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Sample records for strength walking speed

  1. Mobility-Related Fatigue, Walking Speed, and Muscle Strength in Older People

    DEFF Research Database (Denmark)

    Mänty, Minna; Mendes de Leon, Carlos F.; Rantanen, Taina

    2012-01-01

    history, as well as performance-based assessment of walking speed and maximal isometric strength of knee extension, body extension, and handgrip. Results. In the cross-sectional baseline analysis, one unit increase in fatigue score was associated with 0.03 m/s (b = −.03, p ... the degree to which muscle strength accounts for this association. Methods. The study is based on baseline (n = 523) and 5-year follow-up data (n = 292) from a cohort of 75-year-old persons. Standardized assessments include self-report measures of mobility-related fatigue (score range 0–6) and medical......, p strength accounted up to 21% and among men up to 24% for the association. In the prospective analysis, fatigue at baseline was predictive of change in walking speed...

  2. Television Viewing, Walking Speed, and Grip Strength in a Prospective Cohort Study

    Science.gov (United States)

    KEEVIL, VICTORIA L.; WIJNDAELE, KATRIEN; LUBEN, ROBERT; SAYER, AVAN A.; WAREHAM, NICHOLAS J.; KHAW, KAY-TEE

    2015-01-01

    ABSTRACT Purpose Television (TV) watching is the most prevalent sedentary leisure time activity in the United Kingdom. We examined associations between TV viewing time, measured over 10 yr, and two objective measures of physical capability, usual walking speed (UWS) and grip strength. Methods Community-based participants (n = 8623; 48–92 yr old) enrolled in the European Prospective Investigation of Cancer—Norfolk study attended a third health examination (3HC, 2006–2011) for measurement of maximum grip strength (Smedley dynamometer) and UWS. TV viewing time was estimated using a validated questionnaire (n = 6086) administered during two periods (3HC, 2006–2007; 2HC, 1998–2000). Associations between physical capability and TV viewing time category (<2, 2 < 3, 3 < 4, and ≥4 h·d−1) at the 3HC, 2HC, and using an average of the two measures were explored. Sex-stratified analyses were adjusted for age, physical activity, anthropometry, wealth, comorbidity, smoking, and alcohol intake and combined if no sex–TV viewing time interactions were identified. Results Men and women who watched the least TV at the 2HC or 3HC walked at a faster usual pace than those who watched the most TV. There was no evidence of effect modification by sex (Pinteraction = 0.09), and in combined analyses, participants who watched for <2 h·d−1 on average walked 4.29 cm·s−1 (95% confidence interval, 2.56–6.03) faster than those who watched for ≥4 h·d−1, with evidence of a dose–response association (Ptrend < 0.001). However, no strong associations with grip strength were found. Conclusions TV viewing time predicted UWS in older adults. More research is needed to inform public health policy and prospective associations between other measures of sedentariness, such as total sitting time or objectively measured sedentary time, and physical capability should be explored. PMID:25785826

  3. Associations of Walking Speed, Grip Strength, and Standing Balance With Total and Cause-Specific Mortality in a General Population of Japanese Elders.

    Science.gov (United States)

    Nofuji, Yu; Shinkai, Shoji; Taniguchi, Yu; Amano, Hidenori; Nishi, Mariko; Murayama, Hiroshi; Fujiwara, Yoshinori; Suzuki, Takao

    2016-02-01

    Walking speed, grip strength, and standing balance are key components of physical performance in older people. The present study aimed to evaluate (1) associations of these physical performance measures with cause-specific mortality, (2) independent associations of individual physical performance measures with mortality, and (3) the added value of combined use of the 3 physical performance measures in predicting all-cause and cause-specific mortality. Prospective cohort study with a follow-up of 10.5 years. Tokyo Metropolitan Institute of Gerontology Longitudinal Interdisciplinary Study on Aging (TMIG-LISA), Japan. A total of 1085 initially nondisabled older Japanese aged 65 to 89 years. Usual walking speed, grip strength, and standing balance were measured at baseline survey. During follow-up, 324 deaths occurred (122 of cardiovascular disease, 75 of cancer, 115 of other causes, and 12 of unknown causes). All 3 physical performance measures were significantly associated with all-cause, cardiovascular, and other-cause mortality, but not with cancer mortality, independent of potential confounders. When all 3 physical performance measures were simultaneously entered into the model, each was significantly independently associated with all-cause and cardiovascular mortality. The C statistics for all-cause and cardiovascular mortality were significantly increased by adding grip strength and standing balance to walking speed (P balance predicted all-cause, cardiovascular, and other-cause mortality, but not cancer mortality, independent of covariates. Moreover, these 3 components of physical performance were independently associated with all-cause and cardiovascular mortality and their combined use increased prognostic power. Copyright © 2016 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

  4. Activating and relaxing music entrains the speed of beat synchronized walking

    OpenAIRE

    Leman, Marc; Moelants, Dirk; Varewyck, Matthias; Styns, Frederik; van Noorden, Leon; Martens, Jean-Pierre

    2013-01-01

    Inspired by a theory of embodied music cognition, we investigate whether music can entrain the speed of beat synchronized walking. If human walking is in synchrony with the beat and all musical stimuli have the same duration and the same tempo, then differences in walking speed can only be the result of music-induced differences in stride length, thus reflecting the vigor or physical strength of the movement. Participants walked in an open field in synchrony with the beat of 52 different musi...

  5. Effects of walking speed on the step-by-step control of step width.

    Science.gov (United States)

    Stimpson, Katy H; Heitkamp, Lauren N; Horne, Joscelyn S; Dean, Jesse C

    2018-02-08

    Young, healthy adults walking at typical preferred speeds use step-by-step adjustments of step width to appropriately redirect their center of mass motion and ensure mediolateral stability. However, it is presently unclear whether this control strategy is retained when walking at the slower speeds preferred by many clinical populations. We investigated whether the typical stabilization strategy is influenced by walking speed. Twelve young, neurologically intact participants walked on a treadmill at a range of prescribed speeds (0.2-1.2 m/s). The mediolateral stabilization strategy was quantified as the proportion of step width variance predicted by the mechanical state of the pelvis throughout a step (calculated as R 2 magnitude from a multiple linear regression). Our ability to accurately predict the upcoming step width increased over the course of a step. The strength of the relationship between step width and pelvis mechanics at the start of a step was reduced at slower speeds. However, these speed-dependent differences largely disappeared by the end of a step, other than at the slowest walking speed (0.2 m/s). These results suggest that mechanics-dependent adjustments in step width are a consistent component of healthy gait across speeds and contexts. However, slower walking speeds may ease this control by allowing mediolateral repositioning of the swing leg to occur later in a step, thus encouraging slower walking among clinical populations with limited sensorimotor control. Published by Elsevier Ltd.

  6. Walking performance and muscle strength in the later stage poststroke: a nonlinear relationship.

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    Carvalho, Cristiane; Sunnerhagen, Katharina S; Willén, Carin

    2013-05-01

    To evaluate the relation between muscle strength in the lower extremities and walking performance (speed and distance) in subjects in the later stage poststroke and to compare this with normative data. A cross-sectional observational study. University hospital department. Subjects poststroke (n=41; 31 men, 10 women) with a mean age of 59±5.8 years and a time from stroke onset of 52±36 months were evaluated. An urban sample (n=144) of 40- to 79-year-olds (69 men, 75 women) formed the healthy reference group. Not applicable. Muscle strength in the lower extremities was measured with an isokinetic dynamometer and combined into a strength index. Values for the 30-meter walk test for self-selected and maximum speed and the 6-minute walk test were measured. A nonlinear regression model was used. The average strength index was 730±309 in the subjects after stroke compared with 1112±362 in the healthy group. A nonlinear relation between walking performance and muscle strength was evident. The model explained 37% of the variance in self-selected speed in the stroke group and 20% in the healthy group, and 63% and 38%, respectively, in the maximum walking speed. For the 6-minute walk test, the model explained 44% of the variance in the stroke group. Subjects in the later stage poststroke were weaker than the healthy reference group, and their weakness was associated with walking performance. At the same strength index, subjects walked at lower speeds and shorter distances after stroke, indicating that there are multiple impairments that affect walking ability. Treatments focused on increasing muscle strength thus continue to hold promise. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  7. Establishing the Range of Perceptually Natural Visual Walking Speeds for Virtual Walking-In-Place Locomotion

    DEFF Research Database (Denmark)

    Nilsson, Niels Christian; Serafin, Stefania; Nordahl, Rolf

    2014-01-01

    to virtual motion. This paper describes two within-subjects studies performed with the intention of establishing the range of perceptually natural walking speeds for WIP locomotion. In both studies, subjects performed a series of virtual walks while exposed to visual gains (optic flow multipliers) ranging...... from 1.0 to 3.0. Thus, the slowest speed was equal to an estimate of the subjects normal walking speed, while the highest speed was three times greater. The perceived naturalness of the visual speed was assessed using self-reports. The first study compared four different types of movement, namely...... proportional to the degree of underestimation of the virtual speeds for both treadmill-mediated virtual walking and WIP locomotion. Combined, the results constitute a first attempt at establishing a set of guidelines specifying what virtual walking speeds WIP gestures should produce in order to facilitate...

  8. Biomechanical parameters in lower limbs during natural walking and Nordic walking at different speeds.

    Science.gov (United States)

    Dziuba, Alicja K; Żurek, Grzegorz; Garrard, Ian; Wierzbicka-Damska, Iwona

    2015-01-01

    Nordic Walking (NW) is a sport that has a number of benefits as a rehabilitation method. It is performed with specially designed poles and has been often recommended as a physical activity that helps reduce the load to limbs. However, some studies have suggested that these findings might be erroneous. The aim of this paper was to compare the kinematic, kinetic and dynamic parameters of lower limbs between Natural Walking (W) and Nordic Walking (NW) at both low and high walking speeds. The study used a registration system, BTS Smart software and Kistler platform. Eleven subjects walked along a 15-metre path at low (below 2 m⋅s-1) and high (over 2 m⋅s-1) walking speeds. The Davis model was employed for calculations of kinematic, kinetic and dynamic parameters of lower limbs. With constant speed, the support given by Nordic Walking poles does not make the stroke longer and there is no change in pelvic rotation either. The only change observed was much bigger pelvic anteversion in the sagittal plane during fast NW. There were no changes in forces, power and muscle torques in lower limbs. The study found no differences in kinematic, kinetic and dynamic parameters between Natural Walking (W) and Nordic Walking (NW). Higher speeds generate greater ground reaction forces and muscle torques in lower limbs. Gait parameters depend on walking speed rather than on walking style.

  9. Tempo and walking speed with music in the urban context.

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    Franěk, Marek; van Noorden, Leon; Režný, Lukáš

    2014-01-01

    The study explored the effect of music on the temporal aspects of walking behavior in a real outdoor urban setting. First, spontaneous synchronization between the beat of the music and step tempo was explored. The effect of motivational and non-motivational music (Karageorghis et al., 1999) on the walking speed was also studied. Finally, we investigated whether music can mask the effects of visual aspects of the walking route environment, which involve fluctuation of walking speed as a response to particular environmental settings. In two experiments, we asked participants to walk around an urban route that was 1.8 km in length through various environments in the downtown area of Hradec Králové. In Experiment 1, the participants listened to a musical track consisting of world pop music with a clear beat. In Experiment 2, participants were walking either with motivational music, which had a fast tempo and a strong rhythm, or with non-motivational music, which was slower, nice music, but with no strong implication to movement. Musical beat, as well as the sonic character of the music listened to while walking, influenced walking speed but did not lead to precise synchronization. It was found that many subjects did not spontaneously synchronize with the beat of the music at all, and some subjects synchronized only part of the time. The fast, energetic music increases the speed of the walking tempo, while slower, relaxing music makes the walking tempo slower. Further, it was found that listening to music with headphones while walking can mask the influence of the surrounding environment to some extent. Both motivational music and non-motivational music had a larger effect than the world pop music from Experiment 1. Individual differences in responses to the music listened to while walking that were linked to extraversion and neuroticism were also observed. The findings described here could be useful in rhythmic stimulation for enhancing or recovering the features of

  10. Tempo and walking speed with music in the urban context

    Science.gov (United States)

    Franěk, Marek; van Noorden, Leon; Režný, Lukáš

    2014-01-01

    The study explored the effect of music on the temporal aspects of walking behavior in a real outdoor urban setting. First, spontaneous synchronization between the beat of the music and step tempo was explored. The effect of motivational and non-motivational music (Karageorghis et al., 1999) on the walking speed was also studied. Finally, we investigated whether music can mask the effects of visual aspects of the walking route environment, which involve fluctuation of walking speed as a response to particular environmental settings. In two experiments, we asked participants to walk around an urban route that was 1.8 km in length through various environments in the downtown area of Hradec Králové. In Experiment 1, the participants listened to a musical track consisting of world pop music with a clear beat. In Experiment 2, participants were walking either with motivational music, which had a fast tempo and a strong rhythm, or with non-motivational music, which was slower, nice music, but with no strong implication to movement. Musical beat, as well as the sonic character of the music listened to while walking, influenced walking speed but did not lead to precise synchronization. It was found that many subjects did not spontaneously synchronize with the beat of the music at all, and some subjects synchronized only part of the time. The fast, energetic music increases the speed of the walking tempo, while slower, relaxing music makes the walking tempo slower. Further, it was found that listening to music with headphones while walking can mask the influence of the surrounding environment to some extent. Both motivational music and non-motivational music had a larger effect than the world pop music from Experiment 1. Individual differences in responses to the music listened to while walking that were linked to extraversion and neuroticism were also observed. The findings described here could be useful in rhythmic stimulation for enhancing or recovering the features of

  11. Tempo and walking speed with music in the urban context

    Directory of Open Access Journals (Sweden)

    Marek eFranek

    2014-12-01

    Full Text Available The study explored the effect of music on the temporal aspects of walking behavior in a real outdoor urban setting. First, spontaneous synchronization between the beat of the music and step tempo was explored. The effect of motivational and non-motivational music (Karageorghis et al. 1999 on the walking speed was also studied. Finally, we investigated whether music can mask the effects of visual aspects of the walking route environment, which involve fluctuation of walking speed as a response to particular environmental settings. In two experiments, we asked participants to walk around an urban route through various environments in the downtown area of Hradec Králové. In Experiment 1, the participants listened to a musical track consisting of world pop music with a clear beat. In Experiment 2, participants were walking either with motivational music, which had a fast tempo and a strong rhythm, or with non-motivational music, which was slower, nice music, but with no strong implication to movement. Musical beat, as well as the sonic character of the music listened to while walking, influenced walking speed but did not lead to precise synchronization. It was found that many subjects did not spontaneously synchronize with the beat of the music at all, and some subjects synchronized only part of the time. The fast, energetic music increases the speed of the walking tempo, while slower, relaxing music makes the walking tempo slower. Further, it was found that listening to music with headphones while walking can mask the influence of the surrounding environment to some extent. Both motivational music and non-motivational music had a larger effect than the music from Experiment 1. Individual differences in responses to the music listened to while walking that were linked to extraversion and neuroticism were also observed. The findings described here could be useful in rhythmic stimulation for enhancing or recovering the features of movement

  12. Effects of walking and strength training on walking capacity in individuals with claudication: meta-analysis

    Directory of Open Access Journals (Sweden)

    Alessandra de Souza Miranda

    2013-06-01

    Full Text Available CONTEXT: Over the past few years, several clinical trials have been performed to analyze the effects of exercise training on walking ability in patients with intermittent claudication (IC. However, it remains unclear which type of physical exercise provides the maximum benefits in terms of walking ability. OBJECTIVE: To analyze, by means of a meta-analysis, the effects of walking and strength training on the walking capacity in patients with IC. METHODS: Papers analyzing the effects of walking and strength training programs in patients with IC were browsed on the Medline, Lilacs, and Cochrane databases. Randomized clinical trials scoring >4 on the Physiotherapy Evidence Database (PEDro scale and assessing claudication distance (CD and total walking distance (TWD were included in the review. RESULTS: Walking and strength training yielded increases in CD and TWD (P < 0.05. However, walking training yielded greater increases than strength training (P = 0.02. CONCLUSION: Walking and strength training improve walking capacity in patients with IC. However, greater improvements in TWD are obtained with walking training.

  13. Fast visual prediction and slow optimization of preferred walking speed.

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    O'Connor, Shawn M; Donelan, J Maxwell

    2012-05-01

    People prefer walking speeds that minimize energetic cost. This may be accomplished by directly sensing metabolic rate and adapting gait to minimize it, but only slowly due to the compounded effects of sensing delays and iterative convergence. Visual and other sensory information is available more rapidly and could help predict which gait changes reduce energetic cost, but only approximately because it relies on prior experience and an indirect means to achieve economy. We used virtual reality to manipulate visually presented speed while 10 healthy subjects freely walked on a self-paced treadmill to test whether the nervous system beneficially combines these two mechanisms. Rather than manipulating the speed of visual flow directly, we coupled it to the walking speed selected by the subject and then manipulated the ratio between these two speeds. We then quantified the dynamics of walking speed adjustments in response to perturbations of the visual speed. For step changes in visual speed, subjects responded with rapid speed adjustments (lasting 300 s). The timing and direction of these responses strongly indicate that a rapid predictive process informed by visual feedback helps select preferred speed, perhaps to complement a slower optimization process that seeks to minimize energetic cost.

  14. Predicting the walking speed of pedestrians on stairs

    OpenAIRE

    Fujiyama, T.; Tyler, N.

    2010-01-01

    In this paper, we propose a framework in which the behaviour of a pedestrian is predicted based on the characteristics of both the pedestrian and the facility the pedestrian uses. As an example of its application, we develop a model to predict the walking speed of a pedestrian on stairs. We examine the physiology and biomechanics of walking on stairs, and then develop a model that predicts walking speed based on the weight and leg extensor power of the pedestrian, and the gradient of the stai...

  15. Walking speed-related changes in stride time variability: effects of decreased speed

    Directory of Open Access Journals (Sweden)

    Dubost Veronique

    2009-08-01

    Full Text Available Abstract Background Conflicting results have been reported regarding the relationship between stride time variability (STV and walking speed. While some studies failed to establish any relationship, others reported either a linear or a non-linear relationship. We therefore sought to determine the extent to which decrease in self-selected walking speed influenced STV among healthy young adults. Methods The mean value, the standard deviation and the coefficient of variation of stride time, as well as the mean value of stride velocity were recorded while steady-state walking using the GAITRite® system in 29 healthy young adults who walked consecutively at 88%, 79%, 71%, 64%, 58%, 53%, 46% and 39% of their preferred walking speed. Results The decrease in stride velocity increased significantly mean values, SD and CoV of stride time (p Conclusion The results support the assumption that gait variability increases while walking speed decreases and, thus, gait might be more unstable when healthy subjects walk slower compared with their preferred walking speed. Furthermore, these results highlight that a decrease in walking speed can be a potential confounder while evaluating STV.

  16. Activating and relaxing music entrains the speed of beat synchronized walking.

    Science.gov (United States)

    Leman, Marc; Moelants, Dirk; Varewyck, Matthias; Styns, Frederik; van Noorden, Leon; Martens, Jean-Pierre

    2013-01-01

    Inspired by a theory of embodied music cognition, we investigate whether music can entrain the speed of beat synchronized walking. If human walking is in synchrony with the beat and all musical stimuli have the same duration and the same tempo, then differences in walking speed can only be the result of music-induced differences in stride length, thus reflecting the vigor or physical strength of the movement. Participants walked in an open field in synchrony with the beat of 52 different musical stimuli all having a tempo of 130 beats per minute and a meter of 4 beats. The walking speed was measured as the walked distance during a time interval of 30 seconds. The results reveal that some music is 'activating' in the sense that it increases the speed, and some music is 'relaxing' in the sense that it decreases the speed, compared to the spontaneous walked speed in response to metronome stimuli. Participants are consistent in their observation of qualitative differences between the relaxing and activating musical stimuli. Using regression analysis, it was possible to set up a predictive model using only four sonic features that explain 60% of the variance. The sonic features capture variation in loudness and pitch patterns at periods of three, four and six beats, suggesting that expressive patterns in music are responsible for the effect. The mechanism may be attributed to an attentional shift, a subliminal audio-motor entrainment mechanism, or an arousal effect, but further study is needed to figure this out. Overall, the study supports the hypothesis that recurrent patterns of fluctuation affecting the binary meter strength of the music may entrain the vigor of the movement. The study opens up new perspectives for understanding the relationship between entrainment and expressiveness, with the possibility to develop applications that can be used in domains such as sports and physical rehabilitation.

  17. Activating and relaxing music entrains the speed of beat synchronized walking.

    Directory of Open Access Journals (Sweden)

    Marc Leman

    Full Text Available Inspired by a theory of embodied music cognition, we investigate whether music can entrain the speed of beat synchronized walking. If human walking is in synchrony with the beat and all musical stimuli have the same duration and the same tempo, then differences in walking speed can only be the result of music-induced differences in stride length, thus reflecting the vigor or physical strength of the movement. Participants walked in an open field in synchrony with the beat of 52 different musical stimuli all having a tempo of 130 beats per minute and a meter of 4 beats. The walking speed was measured as the walked distance during a time interval of 30 seconds. The results reveal that some music is 'activating' in the sense that it increases the speed, and some music is 'relaxing' in the sense that it decreases the speed, compared to the spontaneous walked speed in response to metronome stimuli. Participants are consistent in their observation of qualitative differences between the relaxing and activating musical stimuli. Using regression analysis, it was possible to set up a predictive model using only four sonic features that explain 60% of the variance. The sonic features capture variation in loudness and pitch patterns at periods of three, four and six beats, suggesting that expressive patterns in music are responsible for the effect. The mechanism may be attributed to an attentional shift, a subliminal audio-motor entrainment mechanism, or an arousal effect, but further study is needed to figure this out. Overall, the study supports the hypothesis that recurrent patterns of fluctuation affecting the binary meter strength of the music may entrain the vigor of the movement. The study opens up new perspectives for understanding the relationship between entrainment and expressiveness, with the possibility to develop applications that can be used in domains such as sports and physical rehabilitation.

  18. Activating and Relaxing Music Entrains the Speed of Beat Synchronized Walking

    Science.gov (United States)

    Leman, Marc; Moelants, Dirk; Varewyck, Matthias; Styns, Frederik; van Noorden, Leon; Martens, Jean-Pierre

    2013-01-01

    Inspired by a theory of embodied music cognition, we investigate whether music can entrain the speed of beat synchronized walking. If human walking is in synchrony with the beat and all musical stimuli have the same duration and the same tempo, then differences in walking speed can only be the result of music-induced differences in stride length, thus reflecting the vigor or physical strength of the movement. Participants walked in an open field in synchrony with the beat of 52 different musical stimuli all having a tempo of 130 beats per minute and a meter of 4 beats. The walking speed was measured as the walked distance during a time interval of 30 seconds. The results reveal that some music is ‘activating’ in the sense that it increases the speed, and some music is ‘relaxing’ in the sense that it decreases the speed, compared to the spontaneous walked speed in response to metronome stimuli. Participants are consistent in their observation of qualitative differences between the relaxing and activating musical stimuli. Using regression analysis, it was possible to set up a predictive model using only four sonic features that explain 60% of the variance. The sonic features capture variation in loudness and pitch patterns at periods of three, four and six beats, suggesting that expressive patterns in music are responsible for the effect. The mechanism may be attributed to an attentional shift, a subliminal audio-motor entrainment mechanism, or an arousal effect, but further study is needed to figure this out. Overall, the study supports the hypothesis that recurrent patterns of fluctuation affecting the binary meter strength of the music may entrain the vigor of the movement. The study opens up new perspectives for understanding the relationship between entrainment and expressiveness, with the possibility to develop applications that can be used in domains such as sports and physical rehabilitation. PMID:23874469

  19. Optimal speeds for walking and running, and walking on a moving walkway.

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    Srinivasan, Manoj

    2009-06-01

    Many aspects of steady human locomotion are thought to be constrained by a tendency to minimize the expenditure of metabolic cost. This paper has three parts related to the theme of energetic optimality: (1) a brief review of energetic optimality in legged locomotion, (2) an examination of the notion of optimal locomotion speed, and (3) an analysis of walking on moving walkways, such as those found in some airports. First, I describe two possible connotations of the term "optimal locomotion speed:" that which minimizes the total metabolic cost per unit distance and that which minimizes the net cost per unit distance (total minus resting cost). Minimizing the total cost per distance gives the maximum range speed and is a much better predictor of the speeds at which people and horses prefer to walk naturally. Minimizing the net cost per distance is equivalent to minimizing the total daily energy intake given an idealized modern lifestyle that requires one to walk a given distance every day--but it is not a good predictor of animals' walking speeds. Next, I critique the notion that there is no energy-optimal speed for running, making use of some recent experiments and a review of past literature. Finally, I consider the problem of predicting the speeds at which people walk on moving walkways--such as those found in some airports. I present two substantially different theories to make predictions. The first theory, minimizing total energy per distance, predicts that for a range of low walkway speeds, the optimal absolute speed of travel will be greater--but the speed relative to the walkway smaller--than the optimal walking speed on stationary ground. At higher walkway speeds, this theory predicts that the person will stand still. The second theory is based on the assumption that the human optimally reconciles the sensory conflict between the forward speed that the eye sees and the walking speed that the legs feel and tries to equate the best estimate of the forward

  20. The Perceived Naturalness of Virtual Walking Speeds during WIP Locomotion

    DEFF Research Database (Denmark)

    Nilsson, Niels Chr.; Serafin, Stefania; Nordahl, Rolf

    2016-01-01

    It is well established that individuals tend to underestimate visually presented walking speeds when relying on treadmills for virtual walking. However, prior to the present studies this perceptual distortion had not been observed in relation to Walking-in-Place (WIP) locomotion, and a number...... to how gait cycle characteristics, visual display properties, and methodological differences affect speed underestimation during treadmill and WIP locomotion. The studies suggested the following: A significant main effect was found for step frequency; both display and geometric field of view were...... inversely proportional to the degree of underestimation; varying degrees of peripheral occlusion and increased HMD weight did not yield significant main effects; and the choice of method (i.e., how the speeds were presented) had a significant effect on the upper and lower bounds of what speeds were...

  1. Measuring In-Home Walking Speed using Wall-Mounted RF Transceiver Arrays

    Science.gov (United States)

    Jacobs, Peter G.; Wan, Eric A.; Schafermeer, Erich; Adenwala, Fatema; Paul, Anindya S.; Preiser, Nick; Kaye, Jeffrey

    2014-01-01

    In this paper we present a new method for passively measuring walking speed using a small array of radio transceivers positioned on the walls of a hallway within a home. As a person walks between a radio transmitter and a receiver, the received signal strength (RSS) detected by the receiver changes in a repeatable pattern that may be used to estimate walking speed without the need for the person to wear any monitoring device. The transceivers are arranged as an array of 4 with a known distance between the array elements. Walking past the first pair of transceivers will cause a peak followed by a second peak when the person passes the second pair of transceivers. The time difference between these peaks is used to estimate walking speed directly. We further show that it is possible to estimate the walking speed by correlating the shape of the signal using a single pair of transceivers positioned across from each other in a hallway or doorframe. RMSE performance was less than 15 cm/s using a 2-element array, and less than 8 cm/s using a 4-element array relative to a gait mat used for ground truth. PMID:25570108

  2. Treadmill Adaptation and Verification of Self-Selected Walking Speed: A Protocol for Children

    Science.gov (United States)

    Amorim, Paulo Roberto S.; Hills, Andrew; Byrne, Nuala

    2009-01-01

    Walking is a common activity of daily life and researchers have used the range 3-6 km.h[superscript -1] as reference for walking speeds habitually used for transportation. The term self-selected (i.e., individual or comfortable walking pace or speed) is commonly used in the literature and is identified as the most efficient walking speed, with…

  3. Loading of Hip Measured by Hip Contact Forces at Different Speeds of Walking and Running.

    Science.gov (United States)

    Giarmatzis, Georgios; Jonkers, Ilse; Wesseling, Mariska; Van Rossom, Sam; Verschueren, Sabine

    2015-08-01

    Exercise plays a pivotal role in maximizing peak bone mass in adulthood and maintaining it through aging, by imposing mechanical loading on the bone that can trigger bone mineralization and growth. The optimal type and intensity of exercise that best enhances bone strength remains, however, poorly characterized, partly because the exact peak loading of the bone produced by the diverse types of exercises is not known. By means of integrated motion capture as an input to dynamic simulations, contact forces acting on the hip of 20 young healthy adults were calculated during walking and running at different speeds. During walking, hip contact forces (HCFs) have a two-peak profile whereby the first peak increases from 4.22 body weight (BW) to 5.41 BW and the second from 4.37 BW to 5.74 BW, by increasing speed from 3 to 6 km/h. During running, there is only one peak HCF that increases from 7.49 BW to 10.01 BW, by increasing speed from 6 to 12 km/h. Speed related profiles of peak HCFs and ground reaction forces (GRFs) reveal a different progression of the two peaks during walking. Speed has a stronger impact on peak HCFs rather than on peak GRFs during walking and running, suggesting an increasing influence of muscle activity on peak HCF with increased speed. Moreover, results show that the first peak of HCF during walking can be predicted best by hip adduction moment, and the second peak of HCF by hip extension moment. During running, peak HCF can be best predicted by hip adduction moment. The present study contributes hereby to a better understanding of musculoskeletal loading during walking and running in a wide range of speeds, offering valuable information to clinicians and scientists exploring bone loading as a possible nonpharmacological osteogenic stimulus. © 2015 American Society for Bone and Mineral Research. © 2015 American Society for Bone and Mineral Research.

  4. Influence of Neuromuscular Noise and Walking Speed on Fall Risk and Dynamic Stability in a 3D Dynamic Walking Model

    OpenAIRE

    Roos, Paulien E.; Dingwell, Jonathan B.

    2013-01-01

    Older adults and those with increased fall risk tend to walk slower. They may do this voluntarily to reduce their fall risk. However, both slower and faster walking speeds can predict increased risk of different types of falls. The mechanisms that contribute to fall risk across speeds are not well known. Faster walking requires greater forward propulsion, generated by larger muscle forces. However, greater muscle activation induces increased signal-dependent neuromuscular noise. These speed-r...

  5. Walking training with cueing of cadence improves walking speed and stride length after stroke more than walking training alone: a systematic review.

    Science.gov (United States)

    Nascimento, Lucas R; de Oliveira, Camila Quel; Ada, Louise; Michaelsen, Stella M; Teixeira-Salmela, Luci F

    2015-01-01

    After stroke, is walking training with cueing of cadence superior to walking training alone in improving walking speed, stride length, cadence and symmetry? Systematic review with meta-analysis of randomised or controlled trials. Adults who have had a stroke. Walking training with cueing of cadence. Four walking outcomes were of interest: walking speed, stride length, cadence and symmetry. This review included seven trials involving 211 participants. Because one trial caused substantial statistical heterogeneity, meta-analyses were conducted with and without this trial. Walking training with cueing of cadence improved walking speed by 0.23 m/s (95% CI 0.18 to 0.27, I(2)=0%), stride length by 0.21 m (95% CI 0.14 to 0.28, I(2)=18%), cadence by 19 steps/minute (95% CI 14 to 23, I(2)=40%), and symmetry by 15% (95% CI 3 to 26, random effects) more than walking training alone. This review provides evidence that walking training with cueing of cadence improves walking speed and stride length more than walking training alone. It may also produce benefits in terms of cadence and symmetry of walking. The evidence appears strong enough to recommend the addition of 30 minutes of cueing of cadence to walking training, four times a week for 4 weeks, in order to improve walking in moderately disabled individuals with stroke. PROSPERO (CRD42013005873). Copyright © 2014 Australian Physiotherapy Association. Published by Elsevier B.V. All rights reserved.

  6. Treadmill walking of the pneumatic biped Lucy: Walking at different speeds and step-lengths

    Science.gov (United States)

    Vanderborght, B.; Verrelst, B.; Van Ham, R.; Van Damme, M.; Versluys, R.; Lefeber, D.

    2008-07-01

    Actuators with adaptable compliance are gaining interest in the field of legged robotics due to their capability to store motion energy and to exploit the natural dynamics of the system to reduce energy consumption while walking and running. To perform research on compliant actuators we have built the planar biped Lucy. The robot has six actuated joints, the ankle, knee and hip of both legs with each joint powered by two pleated pneumatic artificial muscles in an antagonistic setup. This makes it possible to control both the torque and the stiffness of the joint. Such compliant actuators are used in passive walkers to overcome friction when walking over level ground and to improve stability. Typically, this kind of robots is only designed to walk with a constant walking speed and step-length, determined by the mechanical design of the mechanism and the properties of the ground. In this paper, we show that by an appropriate control, the robot Lucy is able to walk at different speeds and step-lengths and that adding and releasing weights does not affect the stability of the robot. To perform these experiments, an automated treadmill was built

  7. Influence of neuromuscular noise and walking speed on fall risk and dynamic stability in a 3D dynamic walking model.

    Science.gov (United States)

    Roos, Paulien E; Dingwell, Jonathan B

    2013-06-21

    Older adults and those with increased fall risk tend to walk slower. They may do this voluntarily to reduce their fall risk. However, both slower and faster walking speeds can predict increased risk of different types of falls. The mechanisms that contribute to fall risk across speeds are not well known. Faster walking requires greater forward propulsion, generated by larger muscle forces. However, greater muscle activation induces increased signal-dependent neuromuscular noise. These speed-related increases in neuromuscular noise may contribute to the increased fall risk observed at faster walking speeds. Using a 3D dynamic walking model, we systematically varied walking speed without and with physiologically-appropriate neuromuscular noise. We quantified how actual fall risk changed with gait speed, how neuromuscular noise affected speed-related changes in fall risk, and how well orbital and local dynamic stability measures predicted changes in fall risk across speeds. When we included physiologically-appropriate noise to the 'push-off' force in our model, fall risk increased with increasing walking speed. Changes in kinematic variability, orbital, and local dynamic stability did not predict these speed-related changes in fall risk. Thus, the increased neuromuscular variability that results from increased signal-dependent noise that is necessitated by the greater muscular force requirements of faster walking may contribute to the increased fall risk observed at faster walking speeds. The lower fall risk observed at slower speeds supports experimental evidence that slowing down can be an effective strategy to reduce fall risk. This may help explain the slower walking speeds observed in older adults and others. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Changes in resting and walking energy expenditure and walking speed during pregnancy in obese women.

    Science.gov (United States)

    Byrne, Nuala M; Groves, Ainsley M; McIntyre, H David; Callaway, Leonie K

    2011-09-01

    Energy-conserving processes reported in undernourished women during pregnancy are a recognized strategy for providing the energy required to support fetal development. Women who are obese before conceiving arguably have sufficient fat stores to support the energy demands of pregnancy without the need to provoke energy-conserving mechanisms. We tested the hypothesis that obese women would show behavioral adaptation [ie, a decrease in self-selected walking (SSW) speed] but not metabolic compensation [ie, a decrease in resting metabolic rate (RMR) or the metabolic cost of walking] during gestation. RMR, SSW speed, metabolic cost of walking, and anthropometric variables were measured in 23 women aged 31 ± 4 y with a BMI (in kg/m(2)) of 33.6 ± 2.5 (mean ± SD) at ≈15 and 30 wk of gestation. RMR was also measured in 2 cohorts of nonpregnant control subjects matched for the age, weight, and height of the pregnant cohort at 15 (n = 23) and 30 (n = 23) wk. Gestational weight gain varied widely (11.3 ± 5.4 kg), and 52% of the women gained more weight than is recommended. RMR increased significantly by an average of 177 ± 176 kcal/d (11 ± 12%; P 80% of the cohort, the net oxygen cost of walking decreased in the same proportion of women. Although the increase in RMR was greater than that explained by weight gain, evidence of both behavioral and biological compensation in the metabolic cost of walking was observed in obese women during gestation. The trial is registered with the Australian Clinical Trials Registry as ACTRN012606000271505.

  9. Tracking Steps on Apple Watch at Different Walking Speeds.

    Science.gov (United States)

    Veerabhadrappa, Praveen; Moran, Matthew Duffy; Renninger, Mitchell D; Rhudy, Matthew B; Dreisbach, Scott B; Gift, Kristin M

    2018-04-09

    QUESTION: How accurate are the step counts obtained from Apple Watch? In this validation study, video steps vs. Apple Watch steps (mean ± SD) were 2965 ± 144 vs. 2964 ± 145 steps; P Apple Watch steps when compared with the manual counts obtained from video recordings. Our study is one of the initial studies to objectively validate the accuracy of the step counts obtained from Apple watch at different walking speeds. Apple Watch tested to be an extremely accurate device for measuring daily step counts for adults.

  10. Effects of changing speed on knee and ankle joint load during walking and running.

    Science.gov (United States)

    de David, Ana Cristina; Carpes, Felipe Pivetta; Stefanyshyn, Darren

    2015-01-01

    Joint moments can be used as an indicator of joint loading and have potential application for sports performance and injury prevention. The effects of changing walking and running speeds on joint moments for the different planes of motion still are debatable. Here, we compared knee and ankle moments during walking and running at different speeds. Data were collected from 11 recreational male runners to determine knee and ankle joint moments during different conditions. Conditions include walking at a comfortable speed (self-selected pacing), fast walking (fastest speed possible), slow running (speed corresponding to 30% slower than running) and running (at 4 m · s(-1) ± 10%). A different joint moment pattern was observed between walking and running. We observed a general increase in joint load for sagittal and frontal planes as speed increased, while the effects of speed were not clear in the transverse plane moments. Although differences tend to be more pronounced when gait changed from walking to running, the peak moments, in general, increased when speed increased from comfortable walking to fast walking and from slow running to running mainly in the sagittal and frontal planes. Knee flexion moment was higher in walking than in running due to larger knee extension. Results suggest caution when recommending walking over running in an attempt to reduce knee joint loading. The different effects of speed increments during walking and running should be considered with regard to the prevention of injuries and for rehabilitation purposes.

  11. Walking speed and subclinical atherosclerosis in healthy older adults: the Whitehall II study

    OpenAIRE

    Hamer, M.; Kivimaki, M.; Lahiri, A.; Yerramasu, A.; Deanfield, J. E.; Marmot, M. G.; Steptoe, A.

    2010-01-01

    Objective Extended walking speed is a predictor of incident cardiovascular disease (CVD) in older individuals, but the ability of an objective short-distance walking speed test to stratify the severity of preclinical conditions remains unclear. This study examined whether performance in an 8-ft walking speed test is associated with metabolic risk factors and subclinical atherosclerosis.Design Cross-sectional.Setting Epidemiological cohort.Participants 530 adults (aged 63 +/- 6 years, 50.3% ma...

  12. Walking speed and subclinical atherosclerosis in healthy older adults: the Whitehall II study

    OpenAIRE

    Hamer, Mark; Kivimaki, Mika; Lahiri, Avijit; Yerramasu, Ajay; Deanfield, John E; Marmot, Michael G; Steptoe, Andrew

    2010-01-01

    Objective Extended walking speed is a predictor of incident cardiovascular disease (CVD) in older individuals, but the ability of an objective short-distance walking speed test to stratify the severity of preclinical conditions remains unclear. This study examined whether performance in an 8-ft walking speed test is associated with metabolic risk factors and subclinical atherosclerosis. Design Cross-sectional. Setting Epidemiological cohort. Participants 530 adults (aged 63?6?years, 50.3% mal...

  13. Walking, running, and resting under time, distance, and average speed constraints: optimality of walk-run-rest mixtures.

    Science.gov (United States)

    Long, Leroy L; Srinivasan, Manoj

    2013-04-06

    On a treadmill, humans switch from walking to running beyond a characteristic transition speed. Here, we study human choice between walking and running in a more ecological (non-treadmill) setting. We asked subjects to travel a given distance overground in a given allowed time duration. During this task, the subjects carried, and could look at, a stopwatch that counted down to zero. As expected, if the total time available were large, humans walk the whole distance. If the time available were small, humans mostly run. For an intermediate total time, humans often use a mixture of walking at a slow speed and running at a higher speed. With analytical and computational optimization, we show that using a walk-run mixture at intermediate speeds and a walk-rest mixture at the lowest average speeds is predicted by metabolic energy minimization, even with costs for transients-a consequence of non-convex energy curves. Thus, sometimes, steady locomotion may not be energy optimal, and not preferred, even in the absence of fatigue. Assuming similar non-convex energy curves, we conjecture that similar walk-run mixtures may be energetically beneficial to children following a parent and animals on long leashes. Humans and other animals might also benefit energetically from alternating between moving forward and standing still on a slow and sufficiently long treadmill.

  14. A Case Study on the Walking Speed of Pedestrian at the Bus Terminal Area

    Directory of Open Access Journals (Sweden)

    Mohamad Ali Mohd Firdaus

    2018-01-01

    Full Text Available Walking speed is one of the factors in understanding the pedestrian walking behaviours. Every pedestrian has different level of walking speed that are regulated by some factors such as gender and age. This study was conducted at a bus terminal area with two objectives in which the first one was to determine the average walking speed of pedestrian by considering the factors of age, gender, people with and without carrying baggage; and the second one was to make a comparison of the average walking speed that considered age as the factor of comparison between pedestrian at the bus terminal area and crosswalk. Demographic factor of pedestrian walking speed in this study are gender and age consist of male, female, and 7 groups of age categories that are children, adult men and women, senior adult men and women, over 70 and disabled person. Data of experiment was obtained by making a video recording of the movement of people that were walking and roaming around at the main lobby for 45 minutes by using a camcorder. Hence, data analysis was done by using software named Human Behaviour Simulator (HBS for analysing the data extracted from the video. The result of this study was male pedestrian walked faster than female with the average of walking speed 1.13m/s and 1.07m/s respectively. Averagely, pedestrian that walked without carrying baggage had higher walking speed compared to pedestrian that were carrying baggage with the speed of 1.02m/s and 0.70m/s respectively. Male pedestrian walks faster than female because they have higher level of stamina and they are mostly taller than female pedestrian. Furthermore, pedestrian with baggage walks slower because baggage will cause distractions such as pedestrian will have more weight to carry and people tend to walk slower.

  15. A Case Study on the Walking Speed of Pedestrian at the Bus Terminal Area

    Science.gov (United States)

    Firdaus Mohamad Ali, Mohd; Salleh Abustan, Muhamad; Hidayah Abu Talib, Siti; Abustan, Ismail; Rahman, Noorhazlinda Abd; Gotoh, Hitoshi

    2018-03-01

    Walking speed is one of the factors in understanding the pedestrian walking behaviours. Every pedestrian has different level of walking speed that are regulated by some factors such as gender and age. This study was conducted at a bus terminal area with two objectives in which the first one was to determine the average walking speed of pedestrian by considering the factors of age, gender, people with and without carrying baggage; and the second one was to make a comparison of the average walking speed that considered age as the factor of comparison between pedestrian at the bus terminal area and crosswalk. Demographic factor of pedestrian walking speed in this study are gender and age consist of male, female, and 7 groups of age categories that are children, adult men and women, senior adult men and women, over 70 and disabled person. Data of experiment was obtained by making a video recording of the movement of people that were walking and roaming around at the main lobby for 45 minutes by using a camcorder. Hence, data analysis was done by using software named Human Behaviour Simulator (HBS) for analysing the data extracted from the video. The result of this study was male pedestrian walked faster than female with the average of walking speed 1.13m/s and 1.07m/s respectively. Averagely, pedestrian that walked without carrying baggage had higher walking speed compared to pedestrian that were carrying baggage with the speed of 1.02m/s and 0.70m/s respectively. Male pedestrian walks faster than female because they have higher level of stamina and they are mostly taller than female pedestrian. Furthermore, pedestrian with baggage walks slower because baggage will cause distractions such as pedestrian will have more weight to carry and people tend to walk slower.

  16. The influence of gait speed on the stability of walking among the elderly.

    Science.gov (United States)

    Fan, Yifang; Li, Zhiyu; Han, Shuyan; Lv, Changsheng; Zhang, Bo

    2016-06-01

    Walking speed is a basic factor to consider when walking exercises are prescribed as part of a training programme. Although associations between walking speed, step length and falling risk have been identified, the relationship between spontaneous walking pattern and falling risk remains unclear. The present study, therefore, examined the stability of spontaneous walking at normal, fast and slow speed among elderly (67.5±3.23) and young (21.4±1.31) individuals. In all, 55 participants undertook a test that involved walking on a plantar pressure platform. Foot-ground contact data were used to calculate walking speed, step length, pressure impulse along the plantar-impulse principal axis and pressure record of time series along the plantar-impulse principal axis. A forward dynamics method was used to calculate acceleration, velocity and displacement of the centre of mass in the vertical direction. The results showed that when the elderly walked at different speeds, their average step length was smaller than that observed among the young (p=0.000), whereas their anterior/posterior variability and lateral variability had no significant difference. When walking was performed at normal or slow speed, no significant between-group difference in cadence was found. When walking at a fast speed, the elderly increased their stride length moderately and their cadence greatly (p=0.012). In summary, the present study found no correlation between fast walking speed and instability among the elderly, which indicates that healthy elderly individuals might safely perform fast-speed walking exercises. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Energy cost of walking: solving the paradox of steady state in the presence of variable walking speed.

    Science.gov (United States)

    Plasschaert, Frank; Jones, Kim; Forward, Malcolm

    2009-02-01

    Measurement of the energy cost of walking in children with cerebral palsy is used for baseline and outcome assessment. However, such testing relies on the establishment of steady state that is deemed present when oxygen consumption is stable. This is often assumed when walking speed is constant but in practice, speed can and does vary naturally. Whilst constant speed is achievable on a treadmill, this is often impractical clinically, thus rendering an energy cost test to an element of subjectivity. This paper attempts to address this issue by presenting a new method for calculating energy cost of walking that automatically applies a mathematically defined threshold for steady state within a (non-treadmill) walking trial and then strips out all of the non-steady state events within that trial. The method is compared with a generic approach that does not remove non-steady state data but rather uses an average value over a complete walking trial as is often used in the clinical environment. Both methods were applied to the calculation of several energy cost of walking parameters of self-selected walking speed in a cohort of unimpaired subjects and children with cerebral palsy. The results revealed that both methods were strongly correlated for each parameter but showed systematic significant differences. It is suggested that these differences are introduced by the rejection of non-steady state data that would otherwise have incorrectly been incorporated into the calculation of the energy cost of walking indices during self-selected walking with its inherent speed variation.

  18. Locomotor Training and Strength and Balance Exercises for Walking Recovery After Stroke: Response to Number of Training Sessions.

    Science.gov (United States)

    Rose, Dorian K; Nadeau, Stephen E; Wu, Samuel S; Tilson, Julie K; Dobkin, Bruce H; Pei, Qinglin; Duncan, Pamela W

    2017-11-01

    Evidence-based guidelines are needed to inform rehabilitation practice, including the effect of number of exercise training sessions on recovery of walking ability after stroke. The objective of this study was to determine the response to increasing number of training sessions of 2 interventions-locomotor training and strength and balance exercises-on poststroke walking recovery. This is a secondary analysis of the Locomotor Experience Applied Post-Stroke (LEAPS) randomized controlled trial. Six rehabilitation sites in California and Florida and participants' homes were used. Participants were adults who dwelled in the community (N=347), had had a stroke, were able to walk at least 3 m (10 ft) with assistance, and had completed the required number of intervention sessions. Participants received 36 sessions (3 times per week for 12 weeks), 90 minutes in duration, of locomotor training (gait training on a treadmill with body-weight support and overground training) or strength and balance training. Talking speed, as measured by the 10-Meter Walk Test, and 6-minute walking distance were assessed before training and following 12, 24, and 36 intervention sessions. Participants at 2 and 6 months after stroke gained in gait speed and walking endurance after up to 36 sessions of treatment, but the rate of gain diminished steadily and, on average, was very low during the 25- to 36-session epoch, regardless of treatment type or severity of impairment. Results may not generalize to people who are unable to initiate a step at 2 months after stroke or people with severe cardiac disease. In general, people who dwelled in the community showed improvements in gait speed and walking distance with up to 36 sessions of locomotor training or strength and balance exercises at both 2 and 6 months after stroke. However, gains beyond 24 sessions tended to be very modest. The tracking of individual response trajectories is imperative in planning treatment. Published by Oxford University

  19. Walking training associated with virtual reality-based training increases walking speed of individuals with chronic stroke: systematic review with meta-analysis

    OpenAIRE

    Juliana M. Rodrigues-Baroni; Lucas R. Nascimento; Louise Ada; Luci F. Teixeira-Salmela

    2014-01-01

    OBJECTIVE: To systematically review the available evidence on the efficacy of walking training associated with virtual reality-based training in patients with stroke. The specific questions were: Is walking training associated with virtual reality-based training effective in increasing walking speed after stroke? Is this type of intervention more effective in increasing walking speed, than non-virtual reality-based walking interventions? METHOD: A systematic review with meta-analysis of rando...

  20. Walking during body-weight-supported treadmill training and acute responses to varying walking speed and body-weight support in ambulatory patients post-stroke.

    Science.gov (United States)

    Aaslund, Mona Kristin; Helbostad, Jorunn Lægdheim; Moe-Nilssen, Rolf

    2013-05-01

    Rehabilitating walking in ambulatory patients post-stroke, with training that is safe, task-specific, intensive, and of sufficient duration, can be challenging. Some challenges can be met by using body-weight-supported treadmill training (BWSTT). However, it is not known to what degree walking characteristics are similar during BWSTT and overground walking. In addition, important questions regarding the training protocol of BWSTT remain unanswered, such as how proportion of body-weight support (BWS) and walking speed affect walking characteristics during training. The objective was therefore to investigate if and how kinematic walking characteristics are different between overground walking and treadmill walking with BWS in ambulatory patients post-stroke, and the acute response of altering walking speed and percent BWS during treadmill walking with BWS. A cross-sectional repeated-measures design was used. Ambulating patients post-stroke walked in slow, preferred, and fast walking speed overground and at comparable speeds on the treadmill with 20% and 40% BWS. Kinematic walking characteristics were obtained using a kinematic sensor attached over the lower back. Forty-four patients completed the protocol. Kinematic walking characteristics were similar during treadmill walking with BWS, compared to walking overground. During treadmill walking, choice of walking speed had greater impact on kinematic walking characteristics than proportion of BWS. Faster walking speeds tended to affect the kinematic walking characteristics positively. This implies that in order to train safely and with sufficient intensity and duration, therapists may choose to include BWSTT in walking rehabilitation also for ambulatory patients post-stroke without aggravating gait pattern during training.

  1. Reliability and Validity of Ten Consumer Activity Trackers Depend on Walking Speed.

    Science.gov (United States)

    Fokkema, Tryntsje; Kooiman, Thea J M; Krijnen, Wim P; VAN DER Schans, Cees P; DE Groot, Martijn

    2017-04-01

    To examine the test-retest reliability and validity of ten activity trackers for step counting at three different walking speeds. Thirty-one healthy participants walked twice on a treadmill for 30 min while wearing 10 activity trackers (Polar Loop, Garmin Vivosmart, Fitbit Charge HR, Apple Watch Sport, Pebble Smartwatch, Samsung Gear S, Misfit Flash, Jawbone Up Move, Flyfit, and Moves). Participants walked three walking speeds for 10 min each; slow (3.2 km·h), average (4.8 km·h), and vigorous (6.4 km·h). To measure test-retest reliability, intraclass correlations (ICC) were determined between the first and second treadmill test. Validity was determined by comparing the trackers with the gold standard (hand counting), using mean differences, mean absolute percentage errors, and ICC. Statistical differences were calculated by paired-sample t tests, Wilcoxon signed-rank tests, and by constructing Bland-Altman plots. Test-retest reliability varied with ICC ranging from -0.02 to 0.97. Validity varied between trackers and different walking speeds with mean differences between the gold standard and activity trackers ranging from 0.0 to 26.4%. Most trackers showed relatively low ICC and broad limits of agreement of the Bland-Altman plots at the different speeds. For the slow walking speed, the Garmin Vivosmart and Fitbit Charge HR showed the most accurate results. The Garmin Vivosmart and Apple Watch Sport demonstrated the best accuracy at an average walking speed. For vigorous walking, the Apple Watch Sport, Pebble Smartwatch, and Samsung Gear S exhibited the most accurate results. Test-retest reliability and validity of activity trackers depends on walking speed. In general, consumer activity trackers perform better at an average and vigorous walking speed than at a slower walking speed.

  2. Energetic consequences of human sociality: walking speed choices among friendly dyads.

    Directory of Open Access Journals (Sweden)

    Janelle Wagnild

    Full Text Available Research has shown that individuals have an optimal walking speed-a speed which minimizes energy expenditure for a given distance. Because the optimal walking speed varies with mass and lower limb length, it also varies with sex, with males in any given population tending to have faster optimal walking speeds. This potentially creates an energetic dilemma for mixed-sex walking groups. Here we examine speed choices made by individuals of varying stature, mass, and sex walking together. Individuals (N = 22 walked around a track alone, with a significant other (with and without holding hands, and with friends of the same and opposite sex while their speeds were recorded every 100 m. Our findings show that males walk at a significantly slower pace to match the females' paces (p = 0.009, when the female is their romantic partner. The paces of friends of either same or mixed sex walking together did not significantly change (p>0.05. Thus significant pace adjustment appears to be limited to romantic partners. These findings have implications for both mobility and reproductive strategies of groups. Because the male carries the energetic burden by adjusting his pace (slowing down 7%, the female is spared the potentially increased caloric cost required to walk together. In energetically demanding environments, we will expect to find gender segregation in group composition, particularly when travelling longer distances.

  3. Improved Walking Capacity and Muscle Strength After Functional Power-Training in Young Children With Cerebral Palsy

    NARCIS (Netherlands)

    van Vulpen, Liesbeth F; de Groot, Sonja; Rameckers, Eugene; Becher, Jules G; Dallmeijer, Annet J

    Background. Strength training programs for children with cerebral palsy (CP) showed inconclusive evidence for improving walking, despite improvements in strength. Recent studies have suggested that strength training with high movement velocity is more effective for improving walking than traditional

  4. Economy, Movement Dynamics, and Muscle Activity of Human Walking at Different Speeds

    DEFF Research Database (Denmark)

    Raffalt, Peter Christian; Guul, Martin Kjær; Nielsen, A. N.

    2017-01-01

    The complex behaviour of human walking with respect to movement variability, economy and muscle activity is speed dependent. It is well known that a U-shaped relationship between walking speed and economy exists. However, it is an open question if the movement dynamics of joint angles and centre...... of mass and muscle activation strategy also exhibit a U-shaped relationship with walking speed. We investigated the dynamics of joint angle trajectories and the centre of mass accelerations at five different speeds ranging from 20 to 180% of the predicted preferred speed (based on Froude speed) in twelve...... healthy males. The muscle activation strategy and walking economy were also assessed. The movement dynamics was investigated using a combination of the largest Lyapunov exponent and correlation dimension. We observed an intermediate stage of the movement dynamics of the knee joint angle and the anterior...

  5. Modulation of walking speed by changing optic flow in persons with stroke

    Directory of Open Access Journals (Sweden)

    Lamontagne Anouk

    2007-06-01

    Full Text Available Abstract Background Walking speed, which is often reduced after stroke, can be influenced by the perception of optic flow (OF speed. The present study aims to: 1 compare the modulation of walking speed in response to OF speed changes between persons with stroke and healthy controls and 2 investigate whether virtual environments (VE manipulating OF speed can be used to promote volitional changes in walking speed post stroke. Methods Twelve persons with stroke and 12 healthy individuals walked on a self-paced treadmill while viewing a virtual corridor in a helmet-mounted display. Two experiments were carried out on the same day. In experiment 1, the speed of an expanding OF was varied sinusoidally at 0.017 Hz (sine duration = 60 s, from 0 to 2 times the subject's comfortable walking speed, for a total duration of 5 minutes. In experiment 2, subjects were exposed to expanding OFs at discrete speeds that ranged from 0.25 to 2 times their comfortable speed. Each test trial was paired with a control trial performed at comfortable speed with matching OF. For each of the test trials, subjects were instructed to walk the distance within the same time as during the immediately preceding control trial. VEs were controlled by the CAREN-2 system (Motek. Instantaneous changes in gait speed (experiment 1 and the ratio of speed changes in the test trial over the control trial (experiment 2 were contrasted between the two groups of subjects. Results When OF speed was changing continuously (experiment 1, an out-of-phase modulation was observed in the gait speed of healthy subjects, such that slower OFs induced faster walking speeds, and vice versa. Persons with stroke displayed weaker (p 0.05, T-test. Conclusion Stroke affects the modulation of gait speed in response to changes in the perception of movement through different OF speeds. Nevertheless, the preservation of even a modest modulation enabled the persons with stroke to increase walking speed when

  6. Osteosarcopenic obesity is associated with reduced handgrip strength, walking abilities, and balance in postmenopausal women.

    Science.gov (United States)

    Ilich, J Z; Inglis, J E; Kelly, O J; McGee, D L

    2015-11-01

    We determined the prevalence of osteosarcopenic obesity (loss of bone and muscle coexistent with increased adiposity) in overweight/obese postmenopausal women and compared their functionality to obese-only women. Results showed that osteosarcopenic obese women were outperformed by obese-only women in handgrip strength and walking/balance abilities indicating their higher risk for mobility impairments. Osteosarcopenic obesity (OSO) is a recently defined triad of osteopenia/osteoporosis, sarcopenia, and adiposity. We identified women with OSO in overweight/obese postmenopausal women and evaluated their functionality comparing them with obese-only (OB) women. Additionally, women with osteopenic/osteoporotic obesity (OO), but no sarcopenia, and those with sarcopenic obesity (SO), but no osteopenia/osteoporosis, were identified and compared. We hypothesized that OSO women will have the lowest scores for each of the functionality measures. Participants (n = 258; % body fat ≥35) were assessed using a Lunar iDXA instrument for bone and body composition. Sarcopenia was determined from negative residuals of linear regression modeled on appendicular lean mass, height, and body fat, using 20th percentile as a cutoff. Participants with T-scores of L1-L4 vertebrae and/or total femur OSO (n = 32) included women with both osteopenia/osteoporosis and sarcopenia, while those with normal bone and no sarcopenia were classified as OB (n = 99). Functionality measures such as handgrip strength, normal/brisk walking speed, and right/left leg stance were evaluated and compared among groups. Women with OSO presented with the lowest handgrip scores, slowest normal and brisk walking speed, and shortest time for each leg stance, but these results were statistically significantly different only from the OB group. These findings indicate a poorer functionality in women presenting with OSO, particularly compared to OB women, increasing the risk for bone fractures and immobility from

  7. Effect of Traffic Noise and Relaxations Sounds on Pedestrian Walking Speed

    Directory of Open Access Journals (Sweden)

    Marek Franěk

    2018-04-01

    Full Text Available Exposure to noise in everyday urban life is considered to be an environmental stressor. A specific outcome of reactions to environmental stress is a fast pace of life that also includes a faster pedestrian walking speed. The present study examined the effect of listening to annoying acoustical stimuli (traffic noise compared with relaxation sounds (forest birdsong on walking speed in a real outdoor urban environment. The participants (N = 83 walked along an urban route of 1.8 km. They listened to either traffic noise or forest birdsong, or they walked without listening to any acoustical stimuli in the control condition. The results showed that participants listening to traffic noise walked significantly faster on the route than both the participants listening to forest birdsong sounds and the participants in the control condition. Participants who listened to forest birdsong walked slightly slower than those under control conditions; however, this difference was not significant. Analysis of the walk experience showed that participants who listened to forest birdsong during the walk liked the route more than those who listened to traffic sounds. The study demonstrated that exposure to traffic noise led to an immediate increase in walking speed. It was also shown that exposure to noise may influence participants’ perception of an environment. The same environment may be more liked in the absence of noise or in the presence of relaxation sounds. The study also documented the positive effect of listening to various kinds of relaxation sounds while walking in an outdoor environment with traffic noise.

  8. Reliability and Validity of Ten Consumer Activity Trackers Depend on Walking Speed

    NARCIS (Netherlands)

    Fokkema, Tryntsje; Kooiman, Thea J. M.; Krijnen, Wim P.; Van der Schans, Cees P.; De Groot, Martijn

    Purpose: To examine the test-retest reliability and validity of ten activity trackers for step counting at three different walking speeds. Methods: Thirty-one healthy participants walked twice on a treadmill for 30 min while wearing 10 activity trackers (Polar Loop, Garmin Vivosmart, Fitbit Charge

  9. Reliability and validity of ten consumer activity trackers depend on walking speed

    NARCIS (Netherlands)

    Fokkema, Tryntsje; Kooiman, Thea; Krijnen, Wim; van der Schans, Cees; de Groot, Martijn

    Purpose: To examine the test–retest reliability and validity of ten activity trackers for step counting at three different walking speeds. Methods: Thirty-one healthy participants walked twice on a treadmill for 30 min while wearing 10 activity trackers (Polar Loop, Garmin Vivosmart, Fitbit Charge

  10. Inertial sensor-based methods in walking speed estimation: a systematic review.

    Science.gov (United States)

    Yang, Shuozhi; Li, Qingguo

    2012-01-01

    Self-selected walking speed is an important measure of ambulation ability used in various clinical gait experiments. Inertial sensors, i.e., accelerometers and gyroscopes, have been gradually introduced to estimate walking speed. This research area has attracted a lot of attention for the past two decades, and the trend is continuing due to the improvement of performance and decrease in cost of the miniature inertial sensors. With the intention of understanding the state of the art of current development in this area, a systematic review on the exiting methods was done in the following electronic engines/databases: PubMed, ISI Web of Knowledge, SportDiscus and IEEE Xplore. Sixteen journal articles and papers in proceedings focusing on inertial sensor based walking speed estimation were fully reviewed. The existing methods were categorized by sensor specification, sensor attachment location, experimental design, and walking speed estimation algorithm.

  11. Inertial Sensor-Based Methods in Walking Speed Estimation: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Qingguo Li

    2012-05-01

    Full Text Available Self-selected walking speed is an important measure of ambulation ability used in various clinical gait experiments. Inertial sensors, i.e., accelerometers and gyroscopes, have been gradually introduced to estimate walking speed. This research area has attracted a lot of attention for the past two decades, and the trend is continuing due to the improvement of performance and decrease in cost of the miniature inertial sensors. With the intention of understanding the state of the art of current development in this area, a systematic review on the exiting methods was done in the following electronic engines/databases: PubMed, ISI Web of Knowledge, SportDiscus and IEEE Xplore. Sixteen journal articles and papers in proceedings focusing on inertial sensor based walking speed estimation were fully reviewed. The existing methods were categorized by sensor specification, sensor attachment location, experimental design, and walking speed estimation algorithm.

  12. The effect of walking speed on local dynamic stability is sensitive to calculation methods

    DEFF Research Database (Denmark)

    Stenum, Jan; Bruijn, Sjoerd M; Jensen, Bente Rona

    2014-01-01

    Local dynamic stability has been assessed by the short-term local divergence exponent (λS), which quantifies the average rate of logarithmic divergence of infinitesimally close trajectories in state space. Both increased and decreased local dynamic stability at faster walking speeds have been...... reported. This might pertain to methodological differences in calculating λS. Therefore, the aim was to test if different calculation methods would induce different effects of walking speed on local dynamic stability. Ten young healthy participants walked on a treadmill at five speeds (60%, 80%, 100%, 120......% and 140% of preferred walking speed) for 3min each, while upper body accelerations in three directions were sampled. From these time-series, λS was calculated by three different methods using: (a) a fixed time interval and expressed as logarithmic divergence per stride-time (λS-a), (b) a fixed number...

  13. The independent effects of speed and propulsive force on joint power generation in walking.

    Science.gov (United States)

    Browne, Michael G; Franz, Jason R

    2017-04-11

    Walking speed is modulated using propulsive forces (F P ) during push-off and both preferred speed and F P decrease with aging. However, even prior to walking slower, reduced F P may be accompanied by potentially unfavorable changes in joint power generation. For example, compared to young adults, older adults exhibit a redistribution of mechanical power generation from the propulsive plantarflexor muscles to more proximal muscles acting across the knee and hip. Here, we used visual biofeedback based on real-time F P measurements to decouple and investigate the interaction between joint-level coordination, whole-body F P , and walking speed. 12 healthy young subjects walked on a dual-belt instrumented treadmill at a range of speeds (0.9-1.3m/s). We immediately calculated the average F P from each speed. Subjects then walked at 1.3m/s while completing a series of biofeedback trials with instructions to match their instantaneous F P to their averaged F P from slower speeds. Walking slower decreased F P and total positive joint work with little effect on relative joint-level contributions. Conversely, subjects walked at a constant speed with reduced F P , not by reducing total positive joint work, but by redistributing the mechanical demands of each step from the plantarflexor muscles during push-off to more proximal leg muscles during single support. Interestingly, these naturally emergent joint- and limb-level biomechanical changes, in the absence of neuromuscular constraints, resemble those due to aging. Our findings provide important reference data to understand the presumably complex interactions between joint power generation, whole-body F P , and walking speed in our aging population. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. [Factors associated with slow walking speed in older adults of a district in Lima, Peru].

    Science.gov (United States)

    Rodríguez, Gabriela; Burga-Cisneros, Daniella; Cipriano, Gabriela; Ortiz, Pedro J; Tello, Tania; Casas, Paola; Aliaga, Elizabeth; Varela, Luis F

    2017-01-01

    To determine the factors associated with slow walking speed in older adults living in a district of Lima, Peru. Analysis of secondary data. Adults older than 60 years were included in the study, while adults with physical conditions who did not allow the evaluation of the walking speed were excluded. The dependent variable was slow walking speed (less than 1 m/s), and the independent variables were sociodemographic, clinical, and geriatric data. Raw and adjusted prevalence ratios (PR) were calculated with 95% confidence intervals (95% CI). The study sample included 416 older adults aged 60 to 99 years, and 41% of the participants met the slow walking speed criterion. The factors associated with slow walking speed in this sample were female gender (PR, 1.45; 95% CI, 1.13-1.88), age > 70 years (PR, 1.73; 95% CI, 1.30- 2.30), lower level of education (PR, 2.07, 95% CI, 1.20-3.55), social-familial problems (PR, 1.66; 95% CI, 1.08-2.54), diabetes mellitus (PR, 1.35; 95% CI, 1.01-1.80), and depression (PR, 1.41; 95% CI, 1.02-1.95). The modifiable factors associated with slow walking speed in older adults included clinical and social-familial problems, and these factors are susceptible to interventions from the early stages of life.

  15. Insect-computer hybrid legged robot with user-adjustable speed, step length and walking gait.

    Science.gov (United States)

    Cao, Feng; Zhang, Chao; Choo, Hao Yu; Sato, Hirotaka

    2016-03-01

    We have constructed an insect-computer hybrid legged robot using a living beetle (Mecynorrhina torquata; Coleoptera). The protraction/retraction and levation/depression motions in both forelegs of the beetle were elicited by electrically stimulating eight corresponding leg muscles via eight pairs of implanted electrodes. To perform a defined walking gait (e.g., gallop), different muscles were individually stimulated in a predefined sequence using a microcontroller. Different walking gaits were performed by reordering the applied stimulation signals (i.e., applying different sequences). By varying the duration of the stimulation sequences, we successfully controlled the step frequency and hence the beetle's walking speed. To the best of our knowledge, this paper presents the first demonstration of living insect locomotion control with a user-adjustable walking gait, step length and walking speed. © 2016 The Author(s).

  16. In vivo fascicle behavior of the flexor hallucis longus muscle at different walking speeds.

    Science.gov (United States)

    Péter, A; Hegyi, A; Finni, T; Cronin, N J

    2017-12-01

    Ankle plantar flexor muscles support and propel the body in the stance phase of locomotion. Besides the triceps surae, flexor hallucis longus muscle (FHL) may also contribute to this role, but very few in vivo studies have examined FHL function during walking. Here, we investigated FHL fascicle behavior at different walking speeds. Ten healthy males walked overground at three different speeds while FHL fascicle length changes were recorded with ultrasound and muscle activity was recorded with surface electromyography (EMG). Fascicle length at heel strike at toe off and at peak EMG activity did not change with speed. Range of FHL fascicle length change (3.5-4.5 and 1.9-2.9 mm on average in stance and push-off phase, respectively), as well as minimum (53.5-54.9 and 53.8-55.7 mm) and maximum (58-58.4 and 56.8-57.7 mm) fascicle length did not change with speed in the stance or push-off phase. Mean fascicle velocity did not change in the stance phase, but increased significantly in the push-off phase between slow and fast walking speeds (P=.021). EMG activity increased significantly in both phases from slow to preferred and preferred to fast speed (P<.02 in all cases). FHL muscle fascicles worked near-isometrically during the whole stance phase (at least during slow walking) and operated at approximately the same length at different walking speeds. FHL and medial gastrocnemius (MG) have similar fiber length to muscle belly length ratios and, according to our results, also exhibit similar fascicle behavior at different walking speeds. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. An observation of the walking speed of evacuees during a simulated tsunami evacuation in Padang, Indonesia

    Science.gov (United States)

    Yosritzal; Kemal, B. M.; Purnawan; Putra, H.

    2018-04-01

    This paper presents a simulation study to observe the walking speed of evacuee in the case of tsunami evacuation in Padang, West Sumatera, Indonesia. A number of 9 volunteers, 6 observers, 1 route with 5 segments were involved in the simulation. The chosen route is the easiest path and the volunteers were ordered to walk in hurry to a particular place which was assumed as a shelter. The observers were placed at some particular places to record the time when an evacuee passes their place. The distance between the observers were measured using a manual distance meter. The study found that the average walking speed during the evacuation was 1.419 m/s. Walking speed is varied by age and gender of the evacuee.

  18. Speed-related spinal excitation from ankle dorsiflexors to knee extensors during human walking

    DEFF Research Database (Denmark)

    Iglesias, Caroline; Nielsen, Jens Bo; Marchand-Pauvert, Véronique

    2008-01-01

    Automatic adjustments of muscle activity throughout the body are required for the maintenance of balance during human walking. One mechanism that is likely to contribute to this control is the heteronymous spinal excitation between human ankle dorsiflexors and knee extensors (CPQ-reflex). Here, we...... investigated the CPQ-reflex at different walking speeds (1-6 km/h) and stride frequencies (0.6-1.3 Hz) in healthy human subjects to provide further evidence of its modulation, and its role in ensuring postural stability during walking. The CPQ-reflex was small or absent at walking speeds below 2-3 km....../h, then increased with walking speeds about 3-4 km/h, and reached a plateau without any further change at walking speeds from 4 to 6 km/h. The reflex showed no modulation when the stride cycle was varied at constant speed (4 km/h; short steps versus long steps). These changes were unlikely to be only caused...

  19. Walking speed and subclinical atherosclerosis in healthy older adults: the Whitehall II study.

    Science.gov (United States)

    Hamer, Mark; Kivimaki, Mika; Lahiri, Avijit; Yerramasu, Ajay; Deanfield, John E; Marmot, Michael G; Steptoe, Andrew

    2010-03-01

    Extended walking speed is a predictor of incident cardiovascular disease (CVD) in older individuals, but the ability of an objective short-distance walking speed test to stratify the severity of preclinical conditions remains unclear. This study examined whether performance in an 8-ft walking speed test is associated with metabolic risk factors and subclinical atherosclerosis. Cross-sectional. Setting Epidemiological cohort. 530 adults (aged 63 + or - 6 years, 50.3% male) from the Whitehall II cohort study with no known history or objective signs of CVD. Electron beam computed tomography and ultrasound was used to assess the presence and extent of coronary artery calcification (CAC) and carotid intima-media thickness (IMT), respectively. High levels of CAC (Agatston score >100) were detected in 24% of the sample; the mean IMT was 0.75 mm (SD 0.15). Participants with no detectable CAC completed the walking course 0.16 s (95% CI 0.04 to 0.28) faster than those with CAC > or = 400. Objectively assessed, but not self-reported, faster walking speed was associated with a lower risk of high CAC (odds ratio 0.62, 95% CI 0.40 to 0.96) and lower IMT (beta=-0.04, 95% CI -0.01 to -0.07 mm) in comparison with the slowest walkers (bottom third), after adjusting for conventional risk factors. Faster walking speed was also associated with lower adiposity, C-reactive protein and low-density lipoprotein cholesterol. Short-distance walking speed is associated with metabolic risk and subclinical atherosclerosis in older adults without overt CVD. These data suggest that a non-aerobically challenging walking test reflects the presence of underlying vascular disease.

  20. EFFECTS OF UNSTABLE SHOES ON ENERGY COST DURING TREADMILL WALKING AT VARIOUS SPEEDS

    Directory of Open Access Journals (Sweden)

    Keiji Koyama

    2012-12-01

    Full Text Available In recent years, shoes having rounded soles in the anterior- posterior direction have been commercially introduced, which are commonly known as unstable shoes (US. However, physiological responses during walking in US, particularly at various speeds, have not been extensively studied to date. The purpose of this study was to investigate the effect of wearing unstable shoes while walking at low to high speeds on the rate of perceived exertion (RPE, muscle activation, oxygen consumption (VO2, and optimum speed. Healthy male adults wore US or normal walking shoes (WS, and walked at various speeds on a treadmill with no inclination. In experiment 1, subjects walked at 3, 4, 5, 6, and 7 km·h-1 (duration, 3 min for all speeds and were recorded on video from the right sagittal plane to calculate the step length and cadence. Simultaneously, electromyogram (EMG was recorded from six different thigh and calf muscles, and the integrated EMG (iEMG was calculated. In experiment 2, RPE, heart rate and VO2 were measured with the walking speed being increased from 3.6 to 7.2 km·h-1 incrementally by 0.9 km·h-1 every 6 min. The optimum speed, defined by the least oxygen cost, was calculated from the fitted quadratic relationship between walking speed and oxygen cost. Wearing US resulted in significantly longer step length and lower cadence compared with WS condition at any given speed. For all speeds, iEMG in the medial gastrocnemius and soleus muscles, heart rate, and VO2 were significantly higher in US than WS. However, RPE and optimum speed (US, 4.75 ± 0.32 km·h-1; WS, 4. 79 ± 0.18 km·h-1 did not differ significantly between the two conditions. These results suggest that unstable shoes can increase muscle activity of lower legs and energy cost without influencing RPE and optimum speed during walking at various speeds

  1. A case study of energy expenditure based on walking speed reduction during walking upstairs situation at a staircase in FKAAS, UTHM, Johor building

    Science.gov (United States)

    Abustan, M. S.; Ali, M. F. M.; Talib, S. H. A.

    2018-04-01

    Walking velocity is a vector quantity that can be determined by calculating the time taken and displacement of a moving objects. In Malaysia, there are very few researches that were done to determine the walking velocity of citizens to be compared with other countries such as the study about walking upstairs during evacuation process is important when emergency case happen, if there are people in underground garages, they have to walk upstairs for exits and look for shelter and the walking velocity of pedestrian in such cases are necessary to be analysed. Therefore, the objective of this study is to determine the walking speed of pedestrian during walking upstairs situation, finding the relationship between pedestrian walking speed and the characteristics of the pedestrian as well as analysing the energy reduction by comparing the walking speed of pedestrian at the beginning and at the end of staircase. In this case study, an experiment was done to determine the average walking speed of pedestrian. The pedestrian has been selected from different gender, physical character, and age. Based on the data collected, the average normal walking speed of male pedestrian was 1.03 m/s while female was 1.08 m/s. During walking upstairs, the walking speed of pedestrian decreased as the number of floor increased. The average speed for the first stairwell was 0.90 m/s and the number decreased to 0.73 m/s for the second stairwell. From the reduction of speed, the energy used has been calculated and the average kinetic energy used was 1.69 J. Hence, the data collected can be used for further research of staircase design and plan of evacuation process.

  2. Walking at speeds close to the preferred transition speed as an approach to obesity treatment

    Directory of Open Access Journals (Sweden)

    Ilić Duško

    2012-01-01

    Full Text Available Introduction. Increasing energy expenditure through certain exercise is an important component of effective interventions to enhance initial weight loss and prevent weight regain. Objective. The purpose of this study was to determine the effect of a 16-week weight loss exercise programme on morpho-functional changes in female adults and to examine the programme effects on two subpopulations with different levels of obesity. Methods. Fifty-six middle-aged women were divided into 2 groups according to their body mass index (BMI: 25-29.9 kg/m2 - overweight (OW and ≥30 kg/m2 - obese (OB. The exercise protocol included a walking technique based on hip rotation at horizontal plane at speeds close to the preferred transition speed (PTS. At the initiation of the study and after 16 weeks of the programme, anthropometric, morphological and cardiovascular parameters of all subjects were assessed. The main effects of Group (OW and OB and Time and the interaction effect of Group by Time were tested by time repeated measures General Linear Model (mixed between-within subjects ANOVA. Results. Mean weight loss during the programme was 10.3 kg and 20.1 kg in OW and OB, respectively. The average fat mass (FM loss was 9.4 kg in OW and 16.9 kg in OB. The Mixed ANOVA revealed a significant Group by Time interaction effects for waist circumference, body weight, body water, fat free mass, FM, %FM and BMI (p<0.05. Conclusion. The applied exercise protocol has proved as beneficial in the treatment of obesity, since it resulted in a significant weight loss and body composition changes. The reduction in body weight was achieved mainly on account of the loss of fat mass.

  3. Required coefficient of friction in the anteroposterior and mediolateral direction during turning at different walking speeds.

    Science.gov (United States)

    Yamaguchi, Takeshi; Suzuki, Akito; Hokkirigawa, Kazuo

    2017-01-01

    This study investigated the required coefficient of friction (RCOF) and the tangent of center of mass (COM)-center of pressure (COP) angle in the mediolateral (ML) and anteroposterior (AP) directions during turning at different walking speeds. Sixteen healthy young adults (8 males and 8 females) participated in this study. The participants were instructed to conduct trials of straight walking and 90° step and spin turns to the right at each of three self-selected speeds (slow, normal, and fast). The ML and AP directions during turning gait were defined using the orientation of the pelvis to construct a body-fixed reference frame. The RCOF values and COM-COP angle tangent in the ML direction during turning at weight acceptance phase were higher than those during straight walking, and those values increased with increasing walking speed. The ML component of the RCOF and COM-COP tangent values during weight acceptance for step turns were higher than those for spin turns. The mean centripetal force during turning tended to increase with an increase in walking speed and had a strong positive correlation with the RCOF values in the ML direction (R = 0.97 during the weight acceptance phase; R = 0.95 during the push-off phase). Therefore, turning, particularly step turn, is likely to cause lateral slip at weight acceptance because of the increased centripetal force compared with straight walking. Future work should test at-risk population and compare with the present results.

  4. Required coefficient of friction in the anteroposterior and mediolateral direction during turning at different walking speeds.

    Directory of Open Access Journals (Sweden)

    Takeshi Yamaguchi

    Full Text Available This study investigated the required coefficient of friction (RCOF and the tangent of center of mass (COM-center of pressure (COP angle in the mediolateral (ML and anteroposterior (AP directions during turning at different walking speeds. Sixteen healthy young adults (8 males and 8 females participated in this study. The participants were instructed to conduct trials of straight walking and 90° step and spin turns to the right at each of three self-selected speeds (slow, normal, and fast. The ML and AP directions during turning gait were defined using the orientation of the pelvis to construct a body-fixed reference frame. The RCOF values and COM-COP angle tangent in the ML direction during turning at weight acceptance phase were higher than those during straight walking, and those values increased with increasing walking speed. The ML component of the RCOF and COM-COP tangent values during weight acceptance for step turns were higher than those for spin turns. The mean centripetal force during turning tended to increase with an increase in walking speed and had a strong positive correlation with the RCOF values in the ML direction (R = 0.97 during the weight acceptance phase; R = 0.95 during the push-off phase. Therefore, turning, particularly step turn, is likely to cause lateral slip at weight acceptance because of the increased centripetal force compared with straight walking. Future work should test at-risk population and compare with the present results.

  5. Vitamin D and walking speed in older adults: Systematic review and meta-analysis.

    Science.gov (United States)

    Annweiler, Cedric; Henni, Samir; Walrand, Stéphane; Montero-Odasso, Manuel; Duque, Gustavo; Duval, Guillaume T

    2017-12-01

    Vitamin D is involved in musculoskeletal health. There is no consensus on a possible association between circulating 25-hydroxyvitamin D (25OHD) concentrations and walking speed, a 'vital sign' in older adults. Our objective was to systematically review and quantitatively assess the association of 25OHD concentration with walking speed. A Medline search was conducted on June 2017, with no limit of date, using the MeSH terms "Vitamin D" OR "Vitamin D Deficiency" combined with "Gait" OR "Gait disorders, Neurologic" OR "Walking speed" OR "Gait velocity". Fixed-effect meta-analyses were performed to compute: i) mean differences in usual and fast walking speeds and Timed Up and Go test (TUG) between participants with severe vitamin D deficiency (≤25nmol/L) (SVDD), vitamin D deficiency (≤50nmol/L) (VDD), vitamin D insufficiency (≤75nmol/L) (VDI) and normal vitamin D (>75nmol/L) (NVD); ii) risk of slow walking speed according to vitamin D status. Of the 243 retrieved studies, 22 observational studies (17 cross-sectional, 5 longitudinal) met the selection criteria. The number of participants ranged between 54 and 4100 (0-100% female). Usual walking speed was slower among participants with hypovitaminosis D, with a clinically relevant difference compared with NVD of -0.18m/s for SVDD, -0.08m/s for VDD and -0.12m/s for VDI. We found similar results regarding the fast walking speed (mean differences -0.04m/s for VDD and VDI compared with NVD) and TUG (mean difference 0.48s for SVDD compared with NVD). A slow usual walking speed was positively associated with SVDD (summary OR=2.17[95%CI:1.52-3.10]), VDD (OR=1.38[95%CI:1.01-1.89]) and VDI (OR=1.38[95%CI:1.04-1.83]), using NVD as the reference. In conclusion, this meta-analysis provides robust evidence that 25OHD concentrations are positively associated with walking speed among adults. Copyright © 2017. Published by Elsevier B.V.

  6. Effects of Door Width and Human Body Size on Walking Speed

    Directory of Open Access Journals (Sweden)

    Jetthumrong Siwalee

    2016-01-01

    Full Text Available Door width is one of the important factors to concern in layout or facilities design because it affects directly to traffic speed and overall traffic time simultaneously. Nowadays, common assessment method is computer simulation which is still not realistic due to the unchanged speed of model while walking through a door. This research aims to study an effect of door width to individual walking speed. Sixty subjects participated in the experiment and performed task by walking through the door that is set the width as 40, 50, 60, 70, 80, 90 and 100 centimetres. The optical motion capture system was used to determine walking speed. The results showed that Fitts’ law was applied to the participants with high weight. Door width below 70 centimetres significantly affected to changing speed at 0-0.5 m. before the door. Additionally, human size also affected changing speed. The factors include shoulder breadth, weight and interaction between shoulder breadth and weight were found to be significant. These factors explained 54.2% of changing speed.

  7. Walking smoothness is associated with self-reported function after accounting for gait speed.

    Science.gov (United States)

    Lowry, Kristin A; Vanswearingen, Jessie M; Perera, Subashan; Studenski, Stephanie A; Brach, Jennifer S

    2013-10-01

    Gait speed has shown to be an indicator of functional status in older adults; however, there may be aspects of physical function not represented by speed but by the quality of movement. The purpose of this study was to determine the relations between walking smoothness, an indicator of the quality of movement based on trunk accelerations, and physical function. Thirty older adults (mean age, 77.7±5.1 years) participated. Usual gait speed was measured using an instrumented walkway. Walking smoothness was quantified by harmonic ratios derived from anteroposterior, vertical, and mediolateral trunk accelerations recorded during overground walking. Self-reported physical function was recorded using the function subscales of the Late-Life Function and Disability Instrument. Anteroposterior smoothness was positively associated with all function components of the Late-Life Function and Disability Instrument, whereas mediolateral smoothness exhibited negative associations. Adjusting for gait speed, anteroposterior smoothness remained associated with the overall and lower extremity function subscales, whereas mediolateral smoothness remained associated with only the advanced lower extremity subscale. These findings indicate that walking smoothness, particularly the smoothness of forward progression, represents aspects of the motor control of walking important for physical function not represented by gait speed alone.

  8. Ankle Plantarflexor Spasticity Does Not Restrict the Recovery of Ankle Plantarflexor Strength or Ankle Power Generation for Push-Off During Walking Following Traumatic Brain Injury.

    Science.gov (United States)

    Williams, Gavin; Banky, Megan; Olver, John

    2016-01-01

    The main aim of this project was to determine the impact of plantarflexor spasticity on muscle performance for ambulant people with traumatic brain injury (TBI). A large metropolitan rehabilitation hospital. Seventy-two ambulant people with TBI who were attending physiotherapy for mobility limitations. Twenty-four participants returned for a 6-month follow-up reassessment. Cross-sectional cohort study. Self-selected walking speed, Tardieu scale, ankle plantarflexor strength, and ankle power generation (APG). Participants with ankle plantarflexor spasticity had significantly lower self-selected walking speed; however, there was no significant difference in ankle plantarflexor strength or APG. Participants with ankle plantarflexor spasticity were not restricted in the recovery of self-selected walking speed, ankle plantarflexor strength, or APG, indicating equivalent ability to improve their mobility over time despite the presence of spasticity. Following TBI, people with ankle plantarflexor spasticity have significantly greater mobility limitations than those without spasticity, yet retain the capacity for recovery of self-selected walking speed, ankle plantarflexor strength, and APG.

  9. Effects of walking speed on asymmetry and bilateral coordination of gait

    Science.gov (United States)

    Plotnik, Meir; Bartsch, Ronny P.; Zeev, Aviva; Giladi, Nir; Hausdorff, Jeffery M.

    2013-01-01

    The mechanisms regulating the bilateral coordination of gait in humans are largely unknown. Our objective was to study how bilateral coordination changes as a result of gait speed modifications during over ground walking. 15 young adults wore force sensitive insoles that measured vertical forces used to determine the timing of the gait cycle events under three walking conditions (i.e., usual-walking, fast and slow). Ground reaction force impact (GRFI) associated with heel-strikes was also quantified, representing the potential contribution of sensory feedback to the regulation of gait. Gait asymmetry (GA) was quantified based on the differences between right and left swing times and the bilateral coordination of gait was assessed using the phase coordination index (PCI), a metric that quantifies the consistency and accuracy of the anti-phase stepping pattern. GA was preserved in the three different gait speeds. PCI was higher (reduced coordination) in the slow gait condition, compared to usual-walking (3.51% vs. 2.47%, respectively, p=0.002), but was not significantly affected in the fast condition. GRFI values were lower in the slow walking as compared to usual-walking and higher in the fast walking condition (pgait related changes in PCI were not associated with the slowed gait related changes in GRFI. The present findings suggest that left-right anti-phase stepping is similar in normal and fast walking, but altered during slowed walking. This behavior might reflect a relative increase in attention resources required to regulate a slow gait speed, consistent with the possibility that cortical function and supraspinal input influences the bilateral coordination of gait. PMID:23680424

  10. Motor fatigue measurement by distance-induced slow down of walking speed in multiple sclerosis.

    Directory of Open Access Journals (Sweden)

    Rémy Phan-Ba

    Full Text Available BACKGROUND AND RATIONALE: Motor fatigue and ambulation impairment are prominent clinical features of people with multiple sclerosis (pMS. We hypothesized that a multimodal and comparative assessment of walking speed on short and long distance would allow a better delineation and quantification of gait fatigability in pMS. Our objectives were to compare 4 walking paradigms: the timed 25-foot walk (T25FW, a corrected version of the T25FW with dynamic start (T25FW(+, the timed 100-meter walk (T100MW and the timed 500-meter walk (T500MW. METHODS: Thirty controls and 81 pMS performed the 4 walking tests in a single study visit. RESULTS: The 4 walking tests were performed with a slower WS in pMS compared to controls even in subgroups with minimal disability. The finishing speed of the last 100-meter of the T500MW was the slowest measurable WS whereas the T25FW(+ provided the fastest measurable WS. The ratio between such slowest and fastest WS (Deceleration Index, DI was significantly lower only in pMS with EDSS 4.0-6.0, a pyramidal or cerebellar functional system score reaching 3 or a maximum reported walking distance ≤ 4000 m. CONCLUSION: The motor fatigue which triggers gait deceleration over a sustained effort in pMS can be measured by the WS ratio between performances on a very short distance and the finishing pace on a longer more demanding task. The absolute walking speed is abnormal early in MS whatever the distance of effort when patients are unaware of ambulation impairment. In contrast, the DI-measured ambulation fatigability appears to take place later in the disease course.

  11. The Time Course of Knee Swelling Post Total Knee Arthroplasty and Its Associations with Quadriceps Strength and Gait Speed.

    Science.gov (United States)

    Pua, Yong-Hao

    2015-07-01

    This study examines the time course of knee swelling post total knee arthroplasty (TKA) and its associations with quadriceps strength and gait speed. Eighty-five patients with unilateral TKA participated. Preoperatively and on post-operative days (PODs) 1, 4, 14, and 90, knee swelling was measured using bioimpedance spectrometry. Preoperatively and on PODs 14 and 90, quadriceps strength was measured using isokinetic dynamometry while fast gait speed was measured using the timed 10-meter walk. On POD1, knee swelling increased ~35% from preoperative levels after which, knee swelling reduced but remained at ~11% above preoperative levels on POD90. In longitudinal, multivariable analyses, knee swelling was associated with quadriceps weakness (P<0.01) and slower gait speed (P=0.03). Interventions to reduce post-TKA knee swelling may be indicated to improve quadriceps strength and gait speed. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. A novel walking speed estimation scheme and its application to treadmill control for gait rehabilitation.

    Science.gov (United States)

    Yoon, Jungwon; Park, Hyung-Soon; Damiano, Diane Louise

    2012-08-28

    Virtual reality (VR) technology along with treadmill training (TT) can effectively provide goal-oriented practice and promote improved motor learning in patients with neurological disorders. Moreover, the VR + TT scheme may enhance cognitive engagement for more effective gait rehabilitation and greater transfer to over ground walking. For this purpose, we developed an individualized treadmill controller with a novel speed estimation scheme using swing foot velocity, which can enable user-driven treadmill walking (UDW) to more closely simulate over ground walking (OGW) during treadmill training. OGW involves a cyclic acceleration-deceleration profile of pelvic velocity that contrasts with typical treadmill-driven walking (TDW), which constrains a person to walk at a preset constant speed. In this study, we investigated the effects of the proposed speed adaptation controller by analyzing the gait kinematics of UDW and TDW, which were compared to those of OGW at three pre-determined velocities. Ten healthy subjects were asked to walk in each mode (TDW, UDW, and OGW) at three pre-determined speeds (0.5 m/s, 1.0 m/s, and 1.5 m/s) with real time feedback provided through visual displays. Temporal-spatial gait data and 3D pelvic kinematics were analyzed and comparisons were made between UDW on a treadmill, TDW, and OGW. The observed step length, cadence, and walk ratio defined as the ratio of stride length to cadence were not significantly different between UDW and TDW. Additionally, the average magnitude of pelvic acceleration peak values along the anterior-posterior direction for each step and the associated standard deviations (variability) were not significantly different between the two modalities. The differences between OGW and UDW and TDW were mainly in swing time and cadence, as have been reported previously. Also, step lengths between OGW and TDW were different for 0.5 m/s and 1.5 m/s gait velocities, and walk ratio between OGS and UDW was

  13. A novel walking speed estimation scheme and its application to treadmill control for gait rehabilitation

    Directory of Open Access Journals (Sweden)

    Yoon Jungwon

    2012-08-01

    Full Text Available Abstract Background Virtual reality (VR technology along with treadmill training (TT can effectively provide goal-oriented practice and promote improved motor learning in patients with neurological disorders. Moreover, the VR + TT scheme may enhance cognitive engagement for more effective gait rehabilitation and greater transfer to over ground walking. For this purpose, we developed an individualized treadmill controller with a novel speed estimation scheme using swing foot velocity, which can enable user-driven treadmill walking (UDW to more closely simulate over ground walking (OGW during treadmill training. OGW involves a cyclic acceleration-deceleration profile of pelvic velocity that contrasts with typical treadmill-driven walking (TDW, which constrains a person to walk at a preset constant speed. In this study, we investigated the effects of the proposed speed adaptation controller by analyzing the gait kinematics of UDW and TDW, which were compared to those of OGW at three pre-determined velocities. Methods Ten healthy subjects were asked to walk in each mode (TDW, UDW, and OGW at three pre-determined speeds (0.5 m/s, 1.0 m/s, and 1.5 m/s with real time feedback provided through visual displays. Temporal-spatial gait data and 3D pelvic kinematics were analyzed and comparisons were made between UDW on a treadmill, TDW, and OGW. Results The observed step length, cadence, and walk ratio defined as the ratio of stride length to cadence were not significantly different between UDW and TDW. Additionally, the average magnitude of pelvic acceleration peak values along the anterior-posterior direction for each step and the associated standard deviations (variability were not significantly different between the two modalities. The differences between OGW and UDW and TDW were mainly in swing time and cadence, as have been reported previously. Also, step lengths between OGW and TDW were different for 0.5 m/s and 1.5 m/s gait velocities

  14. Factors associated with maximal walking speed among older community-living adults

    DEFF Research Database (Denmark)

    Sallinen, Janne; Mänty, Minna; Leinonen, Raija

    2011-01-01

    explained to 38%. Further adjusting for physical activity, smoking status and use of alcohol increased the variation explained by additional 7%. A minor further increase in variability explained was gained by adding chronic diseases and depressive symptoms in the model. In the final model, the single most...... 07330512) involving 605 community-living ambulatory adults aged 75-81 years. Maximal walking speed, leg extensor power, standing balance and body mass index were measured at the research center. Physical activity, smoking, use of alcohol, chronic diseases and depressive symptoms were self-reported using...... standard questionnaires. Results: The mean maximal walking speed was 1.4 m/s (range 0.3-2.9). In linear regression analysis, age, gender and body mass index explained 11% of the variation in maximal walking speed. Adding leg extensor power and standing balance into the model increased the variation...

  15. Effect of walking speed and placement position interactions in determining the accuracy of various newer pedometers

    Directory of Open Access Journals (Sweden)

    Wonil Park

    2014-06-01

    Full Text Available Older types of pedometers had varied levels of accuracy, which ranged from 0% to 45%. In addition, to obtain accurate results, it was also necessary to position them in a certain way. By contrast, newer models can be placed anywhere on the body; however, their accuracy is unknown when they are placed at different body sites. We determined the accuracy of various newer pedometers under controlled laboratory and free walking conditions. A total of 40 participants, who varied widely in age and body mass index, were recruited for the study. The numbers of steps recorded using five different pedometers placed at the waist, the chest, in a pocket, and on an armband were compared against those counted with a hand tally counter. With the exception of one, all the pedometers were accurate at moderate walking speeds, irrespective of their placement on the body. However, the accuracy tended to decrease at slower and faster walking speeds, especially when the pedometers were worn in the pockets or kept in the purse (p < 0.05. In conclusion, most pedometers examined were accurate when they were placed at the waist, chest, and armband irrespective of the walking speed or terrain. However, some pedometers had reduced accuracy when they were kept in a pocket or placed in a purse, especially at a slower and faster walking speeds.

  16. Age-Related Imbalance Is Associated With Slower Walking Speed: An Analysis From the National Health and Nutrition Examination Survey.

    Science.gov (United States)

    Xie, Yanjun J; Liu, Elizabeth Y; Anson, Eric R; Agrawal, Yuri

    Walking speed is an important dimension of gait function and is known to decline with age. Gait function is a process of dynamic balance and motor control that relies on multiple sensory inputs (eg, visual, proprioceptive, and vestibular) and motor outputs. These sensory and motor physiologic systems also play a role in static postural control, which has been shown to decline with age. In this study, we evaluated whether imbalance that occurs as part of healthy aging is associated with slower walking speed in a nationally representative sample of older adults. We performed a cross-sectional analysis of the previously collected 1999 to 2002 National Health and Nutrition Examination Survey (NHANES) data to evaluate whether age-related imbalance is associated with slower walking speed in older adults aged 50 to 85 years (n = 2116). Balance was assessed on a pass/fail basis during a challenging postural task-condition 4 of the modified Romberg Test-and walking speed was determined using a 20-ft (6.10 m) timed walk. Multivariable linear regression was used to evaluate the association between imbalance and walking speed, adjusting for demographic and health-related covariates. A structural equation model was developed to estimate the extent to which imbalance mediates the association between age and slower walking speed. In the unadjusted regression model, inability to perform the NHANES balance task was significantly associated with 0.10 m/s slower walking speed (95% confidence interval: -0.13 to -0.07; P imbalance mediates 12.2% of the association between age and slower walking speed in older adults. In a nationally representative sample, age-related balance limitation was associated with slower walking speed. Balance impairment may lead to walking speed declines. In addition, reduced static postural control and dynamic walking speed that occur with aging may share common etiologic origins, including the decline in visual, proprioceptive, and vestibular sensory and

  17. How much muscle strength is required to walk in a crouch gait?

    NARCIS (Netherlands)

    Steele, K.M.; van der Krogt, M.M.; Schwartz, M.H.; Delp, S.L.

    2012-01-01

    Muscle weakness is commonly cited as a cause of crouch gait in individuals with cerebral palsy; however, outcomes after strength training are variable and mechanisms by which muscle weakness may contribute to crouch gait are unclear. Understanding how much muscle strength is required to walk in a

  18. Obesity does not impair walking economy across a range of speeds and grades.

    Science.gov (United States)

    Browning, Raymond C; Reynolds, Michelle M; Board, Wayne J; Walters, Kellie A; Reiser, Raoul F

    2013-05-01

    Despite the popularity of walking as a form of physical activity for obese individuals, relatively little is known about how obesity affects the metabolic rate, economy, and underlying mechanical energetics of walking across a range of speeds and grades. The purpose of this study was to quantify metabolic rate, stride kinematics, and external mechanical work during level and gradient walking in obese and nonobese adults. Thirty-two obese [18 women, mass = 102.1 (15.6) kg, BMI = 33.9 (3.6) kg/m(2); mean (SD)] and 19 nonobese [10 women, mass = 64.4 (10.6) kg, BMI = 21.6 (2.0) kg/m(2)] volunteers participated in this study. We measured oxygen consumption, ground reaction forces, and lower extremity kinematics while subjects walked on a dual-belt force-measuring treadmill at 11 speeds/grades (0.50-1.75 m/s, -3° to +9°). We calculated metabolic rate, stride kinematics, and external work. Net metabolic rate (Ė net/kg, W/kg) increased with speed or grade across all individuals. Surprisingly and in contrast with previous studies, Ė net/kg was 0-6% less in obese compared with nonobese adults (P = 0.013). External work, although a primary determinant of Ė net/kg, was not affected by obesity across the range of speeds/grades used in this study. We also developed new prediction equations to estimate oxygen consumption and Ė net/kg and found that Ė net/kg was positively related to relative leg mass and step width and negatively related to double support duration. These results suggest that obesity does not impair walking economy across a range of walking speeds and grades.

  19. Genetic Analysis of Daily Maximum Milking Speed by a Random Walk Model in Dairy Cows

    DEFF Research Database (Denmark)

    Karacaören, Burak; Janss, Luc; Kadarmideen, Haja

    Data were obtained from dairy cows stationed at research farm ETH Zurich for maximum milking speed. The main aims of this paper are a) to evaluate if the Wood curve is suitable to model mean lactation curve b) to predict longitudinal breeding values by random regression and random walk models of ...... filter applications: random walk model could give online prediction of breeding values. Hence without waiting for whole lactation records, genetic evaluation could be made when the daily or monthly data is available......Data were obtained from dairy cows stationed at research farm ETH Zurich for maximum milking speed. The main aims of this paper are a) to evaluate if the Wood curve is suitable to model mean lactation curve b) to predict longitudinal breeding values by random regression and random walk models...... of maximum milking speed. Wood curve did not provide a good fit to the data set. Quadratic random regressions gave better predictions compared with the random walk model. However random walk model does not need to be evaluated for different orders of regression coefficients. In addition with the Kalman...

  20. The Effect of Head Mounted Display Weight and Locomotion Method on the Perceived Naturalness of Virtual Walking Speeds

    DEFF Research Database (Denmark)

    Nilsson, Niels Chr.; Serafin, Stefania; Nordahl, Rolf

    This poster details a study investigating the effect of Head Mounted Display (HMD) weight and locomotion method (Walking-In-Place and treadmill walking) on the perceived naturalness of virtual walking speeds. The results revealed significant main effects of movement type, but no significant effec...

  1. The Effect of Maximal Strength Training on Strength, Walking, and Balance in People with Multiple Sclerosis: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Herb I. Karpatkin

    2016-01-01

    Full Text Available There is little literature examining the use of maximal strength training (MST in people with multiple sclerosis (pwMS. This pretest-posttest study examined the effects of a MST program on strength, walking, balance, and fatigue in a sample of pwMS. Seven pwMS (median EDSS 3.0, IQR 1.5 participated in a MST program twice weekly for eight weeks. Strength was assessed with 1-repetition maximum (1RM on each leg. Walking and balance were measured with the 6-Minute Walk Test (6MWT and Berg Balance Scale (BBS, respectively. Fatigue was measured during each week of the program with the Fatigue Severity Scale (FSS. The program was well tolerated, with an attendance rate of 96.4%. Participants had significant improvements in right leg 1RM (t6=-6.032, P=0.001, left leg 1RM (t(6=-5.388, P=0.002, 6MWT distance (t(6=-2.572,P=0.042, and BBS score (Z=-2.371, P=0.018 after the MST intervention. There was no significant change in FSS scores (F(1,3.312=2.411, P=0.092. Participants in the MST program experienced improved balance and walking without an increase in fatigue. This MST program may be utilized by rehabilitation clinicians to improve lower extremity strength, balance, and mobility in pwMS.

  2. Regularity of the Speed of Biased Random Walk in a One-Dimensional Percolation Model

    Science.gov (United States)

    Gantert, Nina; Meiners, Matthias; Müller, Sebastian

    2018-03-01

    We consider biased random walks on the infinite cluster of a conditional bond percolation model on the infinite ladder graph. Axelson-Fisk and Häggström established for this model a phase transition for the asymptotic linear speed \\overline{v} of the walk. Namely, there exists some critical value λ c>0 such that \\overline{v}>0 if λ \\in (0,λ c) and \\overline{v}=0 if λ ≥ λ c. We show that the speed \\overline{v} is continuous in λ on (0,∞) and differentiable on (0,λ c/2). Moreover, we characterize the derivative as a covariance. For the proof of the differentiability of \\overline{v} on (0,λ c/2), we require and prove a central limit theorem for the biased random walk. Additionally, we prove that the central limit theorem fails to hold for λ ≥ λ c/2.

  3. Cross-Cultural Investigation of Male Gait Perception in Relation to Physical Strength and Speed

    Directory of Open Access Journals (Sweden)

    Bernhard Fink

    2017-08-01

    Full Text Available Previous research documents that men and women can accurately judge male physical strength from gait, but also that the sexes differ in attractiveness judgments of strong and weak male walkers. Women’s (but not men’s attractiveness assessments of strong male walkers are higher than for weak male walkers. Here, we extend this research to assessments of strong and weak male walkers in Chile, Germany, and Russia. Men and women judged videos of virtual characters, animated with the walk movements of motion-captured men, on strength and attractiveness. In two countries (Germany and Russia, these videos were additionally presented at 70% (slower and 130% (faster of their original speed. Stronger walkers were judged to be stronger and more attractive than weak walkers, and this effect was independent of country (but not sex. Women tended to provide higher attractiveness judgments to strong walkers, and men tended to provide higher attractiveness judgments to weak walkers. In addition, German and Russian participants rated strong walkers most attractive at slow and fast speed. Thus, across countries men and women can assess male strength from gait, although they tended to differ in attractiveness assessments of strong and weak male walkers. Attractiveness assessments of male gait may be influenced by society-specific emphasis on male physical strength.

  4. Changes in Energy Cost and Total External Work of Muscles in Elite Race Walkers Walking at Different Speeds

    Directory of Open Access Journals (Sweden)

    Chwała Wiesław

    2014-12-01

    Full Text Available The aim of the study was to assess energy cost and total external work (total energy depending on the speed of race walking. Another objective was to determine the contribution of external work to total energy cost of walking at technical, threshold and racing speed in elite competitive race walkers.

  5. Correlation between balance, speed, and walking ability in individuals with chronic hemiparesis

    Directory of Open Access Journals (Sweden)

    Heloisa Maria Jácome de Sousa Britto

    Full Text Available Abstract Alterations in balance and gait are frequently present in patients with hemiparesis. This study aimed at determining whether there is a correlation between static and functional balance, gait speed and walking capacity. To that end, 17 individuals with chronic hemiparesis of both sexes (58.8% men and 42.25 women, mean age of 56.3 ± 9.73 years, took part in the study. Static balance was assessed by computerized baropodometry, under two different sensory conditions: eyes open (EO and eyes closed (EC. Functional balance was evaluated by Berg Balance Scale and walking ability by the Functional Ambulation Classification. Gait speed was assessed by kinemetry. The Kolmogorov-Smirnov test was used to verify data distribution normality. Parametric variables were correlated by Pearson's test and their non-parametric parameters by Spearman's test. Functional balance showed a positive correlation with gait speed (p=0.005; r=0.64 and walking ability (p = 0.019; r = 0.56. Anteroposterior (AP and mediolateral (ML alterations with EO and EC exhibited negative correlations with gait speed (EO: AP amplitude (p = 0.0049 and r = -0.48; mean ML deviation (p = 0.019 and r =-0.56/ EC: mean AP deviation (p = 0.018 and r = -0.56 and mean ML deviation (p = 0.032 and r = -0.52; AP amplitude (p = 0.014 and r = -0.57 and ML amplitude (p = 0.032 and r = -0.52; postural instability (p = 0.019 and r = -0.55 and walking ability (EO: mean AP deviation (p = 0.05 and r = -0.47 and AP amplitude (p = 0.024 and r = -0.54. The results suggest correlations between static and functional balance and gait speed and walking ability, and that balance training can be an important component of gait recovery protocols.

  6. The Combined Effects of Body Weight Support and Gait Speed on Gait Related Muscle Activity: A Comparison between Walking in the Lokomat Exoskeleton and Regular Treadmill Walking

    Science.gov (United States)

    Van Kammen, Klaske; Boonstra, Annemarijke; Reinders-Messelink, Heleen; den Otter, Rob

    2014-01-01

    Background For the development of specialized training protocols for robot assisted gait training, it is important to understand how the use of exoskeletons alters locomotor task demands, and how the nature and magnitude of these changes depend on training parameters. Therefore, the present study assessed the combined effects of gait speed and body weight support (BWS) on muscle activity, and compared these between treadmill walking and walking in the Lokomat exoskeleton. Methods Ten healthy participants walked on a treadmill and in the Lokomat, with varying levels of BWS (0% and 50% of the participants’ body weight) and gait speed (0.8, 1.8, and 2.8 km/h), while temporal step characteristics and muscle activity from Erector Spinae, Gluteus Medius, Vastus Lateralis, Biceps Femoris, Gastrocnemius Medialis, and Tibialis Anterior muscles were recorded. Results The temporal structure of the stepping pattern was altered when participants walked in the Lokomat or when BWS was provided (i.e. the relative duration of the double support phase was reduced, and the single support phase prolonged), but these differences normalized as gait speed increased. Alternations in muscle activity were characterized by complex interactions between walking conditions and training parameters: Differences between treadmill walking and walking in the exoskeleton were most prominent at low gait speeds, and speed effects were attenuated when BWS was provided. Conclusion Walking in the Lokomat exoskeleton without movement guidance alters the temporal step regulation and the neuromuscular control of walking, although the nature and magnitude of these effects depend on complex interactions with gait speed and BWS. If normative neuromuscular control of gait is targeted during training, it is recommended that very low speeds and high levels of BWS should be avoided when possible. PMID:25226302

  7. Clinical tests of ankle plantarflexor strength do not predict ankle power generation during walking.

    Science.gov (United States)

    Kahn, Michelle; Williams, Gavin

    2015-02-01

    The aim of this study was to investigate the relationship between a clinical test of ankle plantarflexor strength and ankle power generation (APG) at push-off during walking. This is a prospective cross-sectional study of 102 patients with traumatic brain injury. Handheld dynamometry was used to measure ankle plantarflexor strength. Three-dimensional gait analysis was performed to quantify ankle power generation at push-off during walking. Ankle plantarflexor strength was only moderately correlated with ankle power generation at push-off (r = 0.43, P < 0.001; 95% confidence interval, 0.26-0.58). There was also a moderate correlation between ankle plantarflexor strength and self-selected walking velocity (r = 0.32, P = 0.002; 95% confidence interval, 0.13-0.48). Handheld dynamometry measures of ankle plantarflexor strength are only moderately correlated with ankle power generation during walking. This clinical test of ankle plantarflexor strength is a poor predictor of calf muscle function during gait in people with traumatic brain injury.

  8. Human growth hormone stabilizes walking and improves strength in a patient with dominantly inherited calpainopathy

    DEFF Research Database (Denmark)

    Prahm, Kira Philipsen; Feldt-Rasmussen, Ulla; Vissing, John

    2017-01-01

    The aim was to investigate if daily low-dose treatment with recombinant human growth hormone (somatropine) can stabilize or improve muscle strength and walking capability in a patient with dominantly inherited calpainopathy. The patient was treated with daily injections of somatropine, except...... for a 6-month pause, over a period of 4.5 years. Efficacy was assessed by repeated muscle dynamometry tests and 6-minute walk tests (6MWT). Strength improved in most muscle groups on treatment, deteriorated in the 6-month off treatment, and improved again when treatment was resumed. The 6MWT stabilized...... during the initial 18-month treatment period, then deteriorated in the 6 months off treatment and improved to pre-trial levels when treatment was resumed. The findings suggest that supplementation with somatropine, within physiological ranges, may improve muscle strength and stabilize walking capability...

  9. Restricted Arm Swing Affects Gait Stability and Increased Walking Speed Alters Trunk Movements in Children with Cerebral Palsy

    Science.gov (United States)

    Delabastita, Tijs; Desloovere, Kaat; Meyns, Pieter

    2016-01-01

    Observational research suggests that in children with cerebral palsy, the altered arm swing is linked to instability during walking. Therefore, the current study investigates whether children with cerebral palsy use their arms more than typically developing children, to enhance gait stability. Evidence also suggests an influence of walking speed on gait stability. Moreover, previous research highlighted a link between walking speed and arm swing. Hence, the experiment aimed to explore differences between typically developing children and children with cerebral palsy taking into account the combined influence of restricting arm swing and increasing walking speed on gait stability. Spatiotemporal gait characteristics, trunk movement parameters and margins of stability were obtained using three dimensional gait analysis to assess gait stability of 26 children with cerebral palsy and 24 typically developing children. Four walking conditions were evaluated: (i) free arm swing and preferred walking speed; (ii) restricted arm swing and preferred walking speed; (iii) free arm swing and high walking speed; and (iv) restricted arm swing and high walking speed. Double support time and trunk acceleration variability increased more when arm swing was restricted in children with bilateral cerebral palsy compared to typically developing children and children with unilateral cerebral palsy. Trunk sway velocity increased more when walking speed was increased in children with unilateral cerebral palsy compared to children with bilateral cerebral palsy and typically developing children and in children with bilateral cerebral palsy compared to typically developing children. Trunk sway velocity increased more when both arm swing was restricted and walking speed was increased in children with bilateral cerebral palsy compared to typically developing children. It is proposed that facilitating arm swing during gait rehabilitation can improve gait stability and decrease trunk movements in

  10. Required coefficient of friction during turning at self-selected slow, normal, and fast walking speeds.

    Science.gov (United States)

    Fino, Peter; Lockhart, Thurmon E

    2014-04-11

    This study investigated the relationship of required coefficient of friction to gait speed, obstacle height, and turning strategy as participants walked around obstacles of various heights. Ten healthy, young adults performed 90° turns around corner pylons of four different heights at their self selected normal, slow, and fast walking speeds using both step and spin turning strategies. Kinetic data was captured using force plates. Results showed peak required coefficient of friction (RCOF) at push off increased with increased speed (slow μ=0.38, normal μ=0.45, and fast μ=0.54). Obstacle height had no effect on RCOF values. The average peak RCOF for fast turning exceeded the OSHA safety guideline for static COF of μ>0.50, suggesting further research is needed into the minimum static COF to prevent slips and falls, especially around corners. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. IMPACT OF BODY WEIGHT SUPPORTED BACKWARD TREADMILL TRAINING ON WALKING SPEED IN CHILDREN WITH SPASTIC DIPLEGIA

    Directory of Open Access Journals (Sweden)

    Hamada El Sayed Abd Allah Ayoub

    2016-10-01

    Full Text Available Background: A lot of the ambulating children with spastic diplegia were able to walk with flexed hips, knees and ankles this gait pattern is known as crouch gait. The most needed functional achievement of diplegic children habilitation is to be able to walk appropriately. The development of an independent and efficient walking is one of the main objectives for children with cerebral palsy especially those with spastic diplegia. Method: Twenty children with spastic diplegia enrolled in this study, they were classified into two groups of equal number, eligibility to our study were ages ranged from seven to ten years, were able to ambulate, They had gait problems and abnormal gait kinematics. The control group (A received selected physical therapy program based on neurodevelopmental approach for such cases, while the study group (B received partial body weight supported backward treadmill training in addition to regular exercise program. Gait pattern was assessed using the Biodex Gait Trainer II for each group pre and post three months of the treatment program. Results: There was statistically significant improvement in walking speed in the study group (P<0.05 with significant difference when comparing post treatment results between groups (p<0.05. Conclusion: These findings suggested that partial body weight supported backward treadmill training can be included as a supplementary therapeutic modality to improve walking speed and functional abilities of children with diplegic cerebral palsy.

  12. Quantitative measures of walking and strength provide insight into brain corticospinal tract pathology in multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Nora E Fritz

    2017-01-01

    Quantitative measures of strength and walking are associated with brain corticospinal tract pathology. The addition of these quantitative measures to basic clinical information explains more of the variance in corticospinal tract fractional anisotropy and magnetization transfer ratio than the basic clinical information alone. Outcome measurement for multiple sclerosis clinical trials has been notoriously challenging; the use of quantitative measures of strength and walking along with tract-specific imaging methods may improve our ability to monitor disease change over time, with intervention, and provide needed guidelines for developing more effective targeted rehabilitation strategies.

  13. Investigating the relationship between energy expenditure, walking speed and angle of turning in humans.

    Directory of Open Access Journals (Sweden)

    M A McNarry

    Full Text Available Recent studies have suggested that changing direction is associated with significant additional energy expenditure. A failure to account for this additional energy expenditure of turning has significant implications in the design and interpretation of health interventions. The purpose of this study was therefore to investigate the influence of walking speed and angle, and their interaction, on energy expenditure in 20 healthy adults (7 female; 28±7 yrs. On two separate days, participants completed a turning protocol at one of 16 speed- (2.5, 3.5, 4.5, 5.5 km∙h-1 and angle (0, 45, 90, 180° combinations, involving three minute bouts of walking, interspersed by three minutes seated rest. Each condition involved 5 m of straight walking before turning through the pre-determined angle with the speed dictated by a digital, auditory metronome. Tri-axial accelerometry and magnetometry were measured at 60 Hz, in addition to gas exchange on a breath-by-breath basis. Mixed models revealed a significant main effect for speed (F = 121.609, P < 0.001 and angle (F = 19.186, P < 0.001 on oxygen uptake ([Formula: see text] and a significant interaction between these parameters (F = 4.433, P < 0.001. Specifically, as speed increased, [Formula: see text] increased but significant increases in [Formula: see text] relative to straight line walking were only observed for 90° and 180° turns at the two highest speeds (4.5 and 5.5 km∙hr-1. These findings therefore highlight the importance of accounting for the quantity and magnitude of turns completed when estimating energy expenditure and have significant implications within both sport and health contexts.

  14. Knee flexor strength and balance control impairment may explain declines during prolonged walking in women with mild multiple sclerosis.

    Science.gov (United States)

    Ramari, Cintia; Moraes, Andréa G; Tauil, Carlos B; von Glehn, Felipe; Motl, Robert; de David, Ana C

    2018-02-01

    Physiological factors such as muscle weakness and balance could explain declines in walking distance by multiple sclerosis (MS) patients. The purpose of this study was to characterize levels and examine associations among decline in walking distance, balance and muscular strength in women with mild MS. Participants included 28 women with mild relapsing-remitting MS and 21 women without MS. We executed the 6-min walk test (6MWT) to verify declines in walking distance. Isokinetic knee flexion (KF) and extension (KE) muscle strength was measured using a dynamometer. Balance was quantified using a force platform, with eyes open and closed, on a rigid and foam surface. The MS patients presented declines in walking, lower KF muscle strength, and worse balance than controls. KF strength and balance correlated with walking in the MS group. The KF strength explained differences between groups in walking. The KF strength and balance presented as predictors of walking slowing down in the 6MWT, in mild MS. Women with mild MS have strength impairment of knee flexor muscles and balance control impairment that may explain walking related motor fatigability during prolonged walking. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. The strength of great apes and the speed of humans.

    Science.gov (United States)

    Walker, Alan

    2009-04-01

    Cliff Jolly developed a causal model of human origins in his paper "The Seed-Eaters," published in 1970. He was one of the first to attempt this, and the paper has since become a classic. I do not have such grand goals; instead, I seek to understand a major difference between the living great apes and humans. More than 50 years ago, Maynard Smith and Savage (1956) showed that the musculoskeletal systems of mammals can be adapted for strength at one extreme and speed at the other but not both. Great apes are adapted for strength--chimpanzees have been shown to be about four times as strong as fit young humans when normalized for body size. The corresponding speed that human limb systems gain at the expense of power is critical for effective human activities such as running, throwing, and manipulation, including tool making. The fossil record can shed light on when the change from power to speed occurred. I outline a hypothesis that suggests that the difference in muscular performance between the two species is caused by chimpanzees having many fewer small motor units than humans, which leads them, in turn, to contract more muscle fibers earlier in any particular task. I outline a histological test of this hypothesis.

  16. Short-term Periodization Models: Effects on Strength and Speed-strength Performance.

    Science.gov (United States)

    Hartmann, Hagen; Wirth, Klaus; Keiner, Michael; Mickel, Christoph; Sander, Andre; Szilvas, Elena

    2015-10-01

    Dividing training objectives into consecutive phases to gain morphological adaptations (hypertrophy phase) and neural adaptations (strength and power phases) is called strength-power periodization (SPP). These phases differ in program variables (volume, intensity, and exercise choice or type) and use stepwise intensity progression and concomitant decreasing volume, converging to peak intensity (peaking phase). Undulating periodization strategies rotate these program variables in a bi-weekly, weekly, or daily fashion. The following review addresses the effects of different short-term periodization models on strength and speed-strength both with subjects of different performance levels and with competitive athletes from different sports who use a particular periodization model during off-season, pre-season, and in-season conditioning. In most periodization studies, it is obvious that the strength endurance sessions are characterized by repetition zones (12-15 repetitions) that induce muscle hypertrophy in persons with a low performance level. Strictly speaking, when examining subjects with a low training level, many periodization studies include mainly hypertrophy sessions interspersed with heavy strength/power sessions. Studies have demonstrated equal or statistically significant higher gains in maximal strength for daily undulating periodization compared with SPP in subjects with a low to moderate performance level. The relatively short intervention period and the lack of concomitant sports conditioning call into question the practical value of these findings for competitive athletes. Possibly owing to differences in mesocycle length, conditioning programs, and program variables, competitive athletes either maintained or improved strength and/or speed-strength performance by integrating daily undulating periodization and SPP during off-season, pre-season and in-season conditioning. In high-performance sports, high-repetition strength training (>15) should be

  17. Assessment of intersegmental coordination of rats during walking at different speeds - Application of continuous relative phase

    DEFF Research Database (Denmark)

    Raffalt, Peter Christian; Nielsen, Louise R; Madsen, Stefan

    2018-01-01

    of the CRP (ACRP) and DP and on the mean ACRP and mean DP was established by statistical parametric mapping (SPM) and a one-way ANOVA for repeated measures. Absolute and relative reliability were assessed by measurement error and intra-class correlation coefficient. The SPM analysis revealed time dependent......The present study investigated the feasibility and reliability of continuous relative phase (CRP) and deviation phase (DP) to assess intersegmental hind limb coordination pattern and coordination variability in rats during walking. Twenty-six adult rats walked at 8 m/min, 12 m/min and 16 m....../min while two-dimensional kinematics were recorded. Segment angles and segment angular velocities of the paw, shank and thigh on the left hind-limb were extracted from 15 strides and CRP was calculated for the paw-shank and shank-thigh coupling. The effect of walking speed on the time point average curve...

  18. The Relationship between Walk Distance and Muscle Strength, Muscle Pain in Visually Disabled People

    Science.gov (United States)

    Akyol, Betül

    2018-01-01

    The purpose of this study is to examine the relationship between six-minute walk test and muscle pain, muscle strength in visually disabled people. The study includes 50 visually disabled people, aged between 17, 21 ± 5,3. Participants were classified into three categories according to their degree of vision (B1, B2, B3). All participants were…

  19. Mildly disabled persons with multiple sclerosis use similar net joint power strategies as healthy controls when walking speed increases

    DEFF Research Database (Denmark)

    Brincks, John; Sørensen, Henrik; Dalgas, Ulrik

    2018-01-01

    flexors in mildly disabled persons with MS and healthy controls at different walking speeds. METHODS:Thirteen persons with MS and thirteen healthy controls participated and peak net joint power was calculated using 3D motion analysis. RESULTS:In general, no differences were found between speed......-matched healthy controls and persons with MS, but the fastest walking speed was significantly higher in healthy controls (2.42 m/s vs. 1.70 m/s). The net joint power increased in hip flexors, hip extensors, hip abductors, knee extensors and plantar flexors in both groups, when walking speed increased. Significant...... correlations between changes in walking speed and changes in net joint power of plantar flexors, hip extensors and hip flexors existed in healthy controls and persons with MS, and in net knee extensor absorption power of persons with MS only. CONCLUSION:In contrast to previous studies, these findings suggest...

  20. The effect of waist twisting on walking speed of an amphibious salamander like robot

    Science.gov (United States)

    Yin, Xin-Yan; Jia, Li-Chao; Wang, Chen; Xie, Guang-Ming

    2016-06-01

    Amphibious salamanders often swing their waist to coordinate quadruped walking in order to improve their crawling speed. A robot with a swing waist joint, like an amphibious salamander, is used to mimic this locomotion. A control method is designed to allow the robot to maintain the rotational speed of its legs continuous and avoid impact between its legs and the ground. An analytical expression is established between the amplitude of the waist joint and the step length. Further, an optimization amplitude is obtained corresponding to the maximum stride. The simulation results based on automatic dynamic analysis of mechanical systems (ADAMS) and physical experiments verify the rationality and validity of this expression.

  1. Linear and Nonlinear Gait Features in Older Adults Walking on Inclined Surfaces at Different Speeds.

    Science.gov (United States)

    Vieira, Marcus Fraga; Rodrigues, Fábio Barbosa; de Sá E Souza, Gustavo Souto; Magnani, Rina Márcia; Lehnen, Georgia Cristina; Andrade, Adriano O

    2017-06-01

    This study evaluated linear and nonlinear gait features in healthy older adults walking on inclined surfaces at different speeds. Thirty-seven active older adults (experimental group) and fifty young adults (control group) walked on a treadmill at 100% and ±20% of their preferred walking speed for 4 min under horizontal (0%), upward (UP) (+8%), and downward (DOWN) (-8%) conditions. Linear gait variability was assessed using the average standard deviation of trunk acceleration between strides (VAR). Gait stability was assessed using the margin of stability (MoS). Nonlinear gait features were assessed by using the maximum Lyapunov exponent, as a measure of local dynamic stability (LDS), and sample entropy (SEn), as a measure of regularity. VAR increased for all conditions, but the interaction effects between treadmill inclination and age, and speed and age were higher for young adults. DOWN conditions showed the lowest stability in the medial-lateral MoS, but not in LDS. LDS was smaller in UP conditions. However, there were no effects of age for either MoS or LDS. The values of SEn decreased almost linearly from the DOWN to the UP conditions, with significant interaction effects of age for anterior-posterior SEn. The overall results supported the hypothesis that inclined surfaces modulate nonlinear gait features and alter linear gait variability, particularly in UP conditions, but there were no significant effects of age for active older adults.

  2. Walking economy is predictably determined by speed, grade, and gravitational load.

    Science.gov (United States)

    Ludlow, Lindsay W; Weyand, Peter G

    2017-11-01

    The metabolic energy that human walking requires can vary by more than 10-fold, depending on the speed, surface gradient, and load carried. Although the mechanical factors determining economy are generally considered to be numerous and complex, we tested a minimum mechanics hypothesis that only three variables are needed for broad, accurate prediction: speed, surface grade, and total gravitational load. We first measured steady-state rates of oxygen uptake in 20 healthy adult subjects during unloaded treadmill trials from 0.4 to 1.6 m/s on six gradients: -6, -3, 0, 3, 6, and 9°. Next, we tested a second set of 20 subjects under three torso-loading conditions (no-load, +18, and +31% body weight) at speeds from 0.6 to 1.4 m/s on the same six gradients. Metabolic rates spanned a 14-fold range from supine rest to the greatest single-trial walking mean (3.1 ± 0.1 to 43.3 ± 0.5 ml O 2 ·kg -body -1 ·min -1 , respectively). As theorized, the walking portion (V̇o 2-walk  =  V̇o 2-gross - V̇o 2-supine-rest ) of the body's gross metabolic rate increased in direct proportion to load and largely in accordance with support force requirements across both speed and grade. Consequently, a single minimum-mechanics equation was derived from the data of 10 unloaded-condition subjects to predict the pooled mass-specific economy (V̇o 2-gross , ml O 2 ·kg -body + load -1 ·min -1 ) of all the remaining loaded and unloaded trials combined ( n = 1,412 trials from 90 speed/grade/load conditions). The accuracy of prediction achieved ( r 2  = 0.99, SEE = 1.06 ml O 2 ·kg -1 ·min -1 ) leads us to conclude that human walking economy is predictably determined by the minimum mechanical requirements present across a broad range of conditions. NEW & NOTEWORTHY Introduced is a "minimum mechanics" model that predicts human walking economy across a broad range of conditions from only three variables: speed, surface grade, and body-plus-load mass. The derivation

  3. Systematics of atom-atom collision strengths at high speeds

    International Nuclear Information System (INIS)

    Gillespie, G.H.; Inokuti, M.

    1980-01-01

    The collision strengths for atom-atom collisions at high speeds are calculated in the first Born approximation. We studied four classes of collisions, distinguished depending upon whether each of the collision partners becomes excited or not. The results of numerical calculations of the collision strengths are presented for all neutral atoms with Z< or =18. The calculations are based on atomic form factors and incoherent scattering functions found in the literature. The relative contribution of each class of collision processes to the total collision cross section is examined in detail. In general, inelastic processes dominate for low-Z atoms, while elastic scattering is more important for large Z. Other systematics of the collision strengths are comprehensively discussed. The relevant experimental literature has been surveyed and the results of this work for the three collision systems H-He, He-He, and H-Ar are compared with the data for electron-loss processes. Finally, suggestions are made for future work in measurements of atom-atom and ion-atom collision cross sections

  4. Maintenance of muscle strength retains a normal metabolic cost in simulated walking after transtibial limb loss

    Science.gov (United States)

    Russell Esposito, Elizabeth

    2018-01-01

    Recent studies on relatively young and fit individuals with limb loss suggest that maintaining muscle strength after limb loss may mitigate the high metabolic cost of walking typically seen in the larger general limb loss population. However, these data are cross-sectional and the muscle strength prior to limb loss is unknown, and it is therefore difficult to draw causal inferences on changes in strength and gait energetics. Here we used musculoskeletal modeling and optimal control simulations to perform a longitudinal study (25 virtual “subjects”) of the metabolic cost of walking pre- and post-limb loss (unilateral transtibial). Simulations of walking were first performed pre-limb loss on a model with two intact biological legs, then post-limb loss on a model with a unilateral transtibial prosthesis, with a cost function that minimized the weighted sum of gait deviations plus metabolic cost. Metabolic costs were compared pre- vs. post-limb loss, with systematic modifications to the muscle strength and prosthesis type (passive, powered) in the post-limb loss model. The metabolic cost prior to limb loss was 3.44±0.13 J/m/kg. After limb loss, with a passive prosthesis the metabolic cost did not increase above the pre-limb loss cost if pre-limb loss muscle strength was maintained (mean -0.6%, p = 0.17, d = 0.17). With 10% strength loss the metabolic cost with the passive prosthesis increased (mean +5.9%, p loss cost for all subjects with strength losses of 10% and 20%, but increased for all subjects with strength loss of 30% (mean +5.9%, p loss, and that a gait with minimal deviations can be achieved when muscle strength is sufficiently high, even when using a passive prosthesis. PMID:29329344

  5. Mildly disabled persons with multiple sclerosis use similar net joint power strategies as healthy controls when walking speed increases.

    Science.gov (United States)

    Brincks, John; Christensen, Lars Ejsing; Rehnquist, Mette Voigt; Petersen, Jesper; Sørensen, Henrik; Dalgas, Ulrik

    2018-01-01

    To improve walking in persons with multiple sclerosis (MS), it is essential to understand the underlying mechanisms of walking. This study examined strategies in net joint power generated or absorbed by hip flexors, hip extensors, hip abductors, knee extensors, and plantar flexors in mildly disabled persons with MS and healthy controls at different walking speeds. Thirteen persons with MS and thirteen healthy controls participated and peak net joint power was calculated using 3D motion analysis. In general, no differences were found between speed-matched healthy controls and persons with MS, but the fastest walking speed was significantly higher in healthy controls (2.42 m/s vs. 1.70 m/s). The net joint power increased in hip flexors, hip extensors, hip abductors, knee extensors and plantar flexors in both groups, when walking speed increased. Significant correlations between changes in walking speed and changes in net joint power of plantar flexors, hip extensors and hip flexors existed in healthy controls and persons with MS, and in net knee extensor absorption power of persons with MS only. In contrast to previous studies, these findings suggest that mildly disabled persons with MS used similar kinetic strategies as healthy controls to increase walking speed.

  6. Effect of walking speed on the gait of king penguins: An accelerometric approach.

    Science.gov (United States)

    Willener, Astrid S T; Handrich, Yves; Halsey, Lewis G; Strike, Siobhán

    2015-12-21

    Little is known about non-human bipedal gaits. This is probably due to the fact that most large animals are quadrupedal and that non-human bipedal animals are mostly birds, whose primary form of locomotion is flight. Very little research has been conducted on penguin pedestrian locomotion with the focus instead on their associated high energy expenditure. In animals, tri-axial accelerometers are frequently used to estimate physiological energy cost, as well as to define the behaviour pattern of a species, or the kinematics of swimming. In this study, we showed how an accelerometer-based technique could be used to determine the biomechanical characteristics of pedestrian locomotion. Eight king penguins, which represent the only family of birds to have an upright bipedal gait, were trained to walk on a treadmill. The trunk tri-axial accelerations were recorded while the bird was walking at four different speeds (1.0, 1.2, 1.4 and 1.6km/h), enabling the amplitude of dynamic body acceleration along the three axes (amplitude of DBAx, DBAy and DBAz), stride frequency, waddling and leaning amplitude, as well as the leaning angle to be defined. The magnitude of the measured variables showed a significant increase with increasing speed, apart from the backwards angle of lean, which decreased with increasing speed. The variability of the measured variables also showed a significant increase with speed apart from the DBAz amplitude, the waddling amplitude, and the leaning angle, where no significant effect of the walking speed was found. This paper is the first approach to describe 3D biomechanics with an accelerometer on wild animals, demonstrating the potential of this technique. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Is perception of self-motion speed a necessary condition for intercepting a moving target while walking?

    Science.gov (United States)

    Morice, Antoine H P; Wallet, Grégory; Montagne, Gilles

    2014-04-30

    While it has been shown that the Global Optic Flow Rate (GOFR) is used in the control of self-motion speed, this study examined its relevance in the control of interceptive actions while walking. We asked participants to intercept approaching targets by adjusting their walking speed in a virtual environment, and predicted that the influence of the GOFR depended on their interception strategy. Indeed, unlike the Constant Bearing Angle (CBA), the Modified Required Velocity (MRV) strategy relies on the perception of self-displacement speed. On the other hand, the CBA strategy involves specific speed adjustments depending on the curvature of the target's trajectory, whereas the MRV does not. We hypothesized that one strategy is selected among the two depending on the informational content of the environment. We thus manipulated the curvature and display of the target's trajectory, and the relationship between physical walking speed and the GOFR (through eye height manipulations). Our results showed that when the target trajectory was not displayed, walking speed profiles were affected by curvature manipulations. Otherwise, walking speed profiles were less affected by curvature manipulations and were affected by the GOFR manipulations. Taken together, these results show that the use of the GOFR for intercepting a moving target while walking depends on the informational content of the environment. Finally we discuss the complementary roles of these two perceptual-motor strategies. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  8. Prefrontal, posterior parietal and sensorimotor network activity underlying speed control during walking

    Directory of Open Access Journals (Sweden)

    Thomas C Bulea

    2015-05-01

    Full Text Available Accumulating evidence suggests cortical circuits may contribute to control of human locomotion. Here, noninvasive electroencephalography (EEG recorded from able-bodied volunteers during a novel treadmill walking paradigm was used to assess neural correlates of walking. A systematic processing method, including a recently developed subspace reconstruction algorithm, reduced movement-related EEG artifact prior to independent component analysis and dipole source localization. We quantified cortical activity while participants tracked slow and fast target speeds across two treadmill conditions: an active mode that adjusted belt speed based on user movements and a passive mode reflecting a typical treadmill. Our results reveal frequency specific, multi-focal task related changes in cortical oscillations elicited by active walking. Low γ band power, localized to the prefrontal and posterior parietal cortices, was significantly increased during double support and early swing phases, critical points in the gait cycle since the active controller adjusted speed based on pelvis position and swing foot velocity. These phasic γ band synchronizations provide evidence that prefrontal and posterior parietal networks, previously implicated in visuo-spatial and somotosensory integration, are engaged to enhance lower limb control during gait. Sustained μ and β band desynchronization within sensorimotor cortex, a neural correlate for movement, was observed during walking thereby validating our methods for isolating cortical activity. Our results also demonstrate the utility of EEG recorded during locomotion for probing the multi-regional cortical networks which underpin its execution. For example, the cortical network engagement elicited by the active treadmill suggests that it may enhance neuroplasticity for more effective motor training.

  9. Effect of the walking speed to the lower limb joint angular displacements, joint moments and ground reaction forces during walking in water.

    Science.gov (United States)

    Miyoshi, Tasuku; Shirota, Takashi; Yamamoto, Shin-ichiro; Nakazawa, Kimitaka; Akai, Masami

    2004-06-17

    The purpose of this study was to compare the changes in ground reaction forces (GRF), joint angular displacements (JAD), joint moments (JM) and electromyographic (EMG) activities that occur during walking at various speeds in water and on land. Fifteen healthy adults participated in this study. In the water experiments, the water depth was adjusted so that body weight was reduced by 80%. A video-motion analysis system and waterproof force platform was used to obtain kinematics and kinetics data and to calculate the JMs. Results revealed that (1) the anterior-posterior GRF patterns differed between walking in water and walking on land, whereas the medio-lateral GRF patterns were similar, (2) the JAD patterns of the hip and ankle were similar between water- and land-walking, whereas the range of motion at the knee joint was lower in water than on land, (3) the JMs in all three joints were lower in water than on land throughout the stance phase, and (4) the hip joint extension moment and hip extensor muscle EMG activity were increased as walking speed increase during walking in water. Rehabilitative water-walking exercise could be designed to incorporate large-muscle activities, especially of the lower-limb extensor muscles, through full joint range of motion and minimization of joint moments.

  10. Human Skeleton Model Based Dynamic Features for Walking Speed Invariant Gait Recognition

    Directory of Open Access Journals (Sweden)

    Jure Kovač

    2014-01-01

    Full Text Available Humans are able to recognize small number of people they know well by the way they walk. This ability represents basic motivation for using human gait as the means for biometric identification. Such biometrics can be captured at public places from a distance without subject's collaboration, awareness, and even consent. Although current approaches give encouraging results, we are still far from effective use in real-life applications. In general, methods set various constraints to circumvent the influence of covariate factors like changes of walking speed, view, clothing, footwear, and object carrying, that have negative impact on recognition performance. In this paper we propose a skeleton model based gait recognition system focusing on modelling gait dynamics and eliminating the influence of subjects appearance on recognition. Furthermore, we tackle the problem of walking speed variation and propose space transformation and feature fusion that mitigates its influence on recognition performance. With the evaluation on OU-ISIR gait dataset, we demonstrate state of the art performance of proposed methods.

  11. Impact of a Pilot Videogame-Based Physical Activity Program on Walking Speed in Adults with Schizophrenia.

    Science.gov (United States)

    Leutwyler, H; Hubbard, E; Cooper, B A; Dowling, G

    2017-11-10

    The purpose of this report is to describe the impact of a videogame-based physical activity program using the Kinect for Xbox 360 game system (Microsoft, Redmond, WA) on walking speed in adults with schizophrenia. In this randomized controlled trial, 28 participants played either an active videogame for 30 min (intervention group) or played a sedentary videogame for 30 min (control group), once a week for 6 weeks. Walking speed was measured objectively with the Short Physical Performance Battery at enrollment and at the end of the 6-week program. The intervention group (n = 13) showed an average improvement in walking speed of 0.08 m/s and the control group (n = 15) showed an average improvement in walking speed of 0.03 m/s. Although the change in walking speed was not statistically significant, the intervention group had between a small and substantial clinically meaningful change. The results suggest a videogame based physical activity program provides clinically meaningful improvement in walking speed, an important indicator of health status.

  12. Self-paced versus fixed speed walking and the effect of virtual reality in children with cerebral palsy.

    Science.gov (United States)

    Sloot, Lizeth H; Harlaar, Jaap; van der Krogt, Marjolein M

    2015-10-01

    While feedback-controlled treadmills with a virtual reality could potentially offer advantages for clinical gait analysis and training, the effect of self-paced walking and the virtual environment on the gait pattern of children and different patient groups remains unknown. This study examined the effect of self-paced (SP) versus fixed speed (FS) walking and of walking with and without a virtual reality (VR) in 11 typically developing (TD) children and nine children with cerebral palsy (CP). We found that subjects walked in SP mode with twice as much between-stride walking speed variability (pinteraction effects between SP and group (TD versus CP) were found for five out of 33 parameters. This suggests that children with CP might need more time to familiarize to SP walking, however, these differences were generally too small to be clinically relevant. The VR environment did not affect the kinematic or kinetic parameters, but walking with VR was rated as more similar to overground walking by both groups (p=0.02). The results of this study indicate that both SP and FS walking, with and without VR, can be used interchangeably for treadmill-based clinical gait analysis in children with and without CP. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Differences in physical aging measured by walking speed: evidence from the English Longitudinal Study of Ageing.

    Science.gov (United States)

    Weber, Daniela

    2016-01-28

    Physical functioning and mobility of older populations are of increasing interest when populations are aging. Lower body functioning such as walking is a fundamental part of many actions in daily life. Limitations in mobility threaten independent living as well as quality of life in old age. In this study we examine differences in physical aging and convert those differences into the everyday measure of single years of age. We use the English Longitudinal Study of Ageing, which was collected biennially between 2002 and 2012. Data on physical performance, health as well as information on economics and demographics of participants were collected. Lower body performance was assessed with two timed walks at normal pace each of 8 ft (2.4 m) of survey participants aged at least 60 years. We employed growth curve models to study differences in physical aging and followed the characteristic-based age approach to illustrate those differences in single years of age. First, we examined walking speed of about 11,700 English individuals, and identified differences in aging trajectories by sex and other characteristics (e.g. education, occupation, regional wealth). Interestingly, higher educated and non-manual workers outperformed their counterparts for both men and women. Moreover, we transformed the differences between subpopulations into single years of age to demonstrate the magnitude of those gaps, which appear particularly high at early older ages. This paper expands research on aging and physical performance. In conclusion, higher education provides an advantage in walking of up to 15 years for men and 10 years for women. Thus, enhancements in higher education have the potential to ensure better mobility and independent living in old age for a longer period.

  14. Swiss ball exercises improve muscle strength and walking performance in ankylosing spondylitis: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Marcelo Cardoso de Souza

    Full Text Available ABSTRACT Objective: The purpose was to evaluate the effectiveness of a progressive muscle strengthening program using a Swiss ball for AS patients. Methods: Sixty patients with AS were randomized into the intervention group (IG or the control group (CG. Eight exercises were performed by the IG patients with free weights on a Swiss ball two times per week for 16 weeks. The evaluations were performed by a blinded evaluator at baseline and after 4, 8, 12 and 16 weeks using the following instruments: the one-repetition maximum test (1 RM, BASMI, BASFI, HAQ-S, SF-36, 6-minute walk test, time up and go test, BASDAI, ASDAS, ESR and CRP dosage and Likert scale. Results: There was a statistical difference between groups for: strength (1 RM capacity in the following exercises: abdominal, rowing, squat, triceps and reverse fly (p < 0.005; 6-minute walk test (p < 0.001; timed up and go test (p = 0.025 and Likert scale (p < 0.001, all of them with better results for the IG. No differences were observed between the groups with respect to the functional capacity evaluation using the BASFI, HAQ-S, BASMI, SF-36, TUG, ASDAS, ESR and CPR dosage. Conclusions: Progressive muscle strengthening using a Swiss ball is effective for improving muscle strength and walking performance in patients with AS.

  15. Explosive strength training improves speed and agility in wheelchair basketball athletes

    OpenAIRE

    Tarik Ozmen; Bekir Yuktasir; Necmiye Un Yildirim; Birol Yalcin; Mark ET Willems

    2014-01-01

    INTRODUCTION: Wheelchair basketball is a paralympic sport characterized by intermittent high-intensity activities that require explosive strength and speed. OBJECTIVE: To investigate the effect of explosive strength training on speed and agility performance in wheelchair basketball players. METHODS: Ten male wheelchair basketball players (Mage=31±4 yrs) were divided into two groups [i.e. explosive strength training (ES); control (CN)] based on International Wheelchair Basketball Fede...

  16. Walking, running, and resting under time, distance, and average speed constraints: optimality of walk–run–rest mixtures

    Science.gov (United States)

    Long, Leroy L.; Srinivasan, Manoj

    2013-01-01

    On a treadmill, humans switch from walking to running beyond a characteristic transition speed. Here, we study human choice between walking and running in a more ecological (non-treadmill) setting. We asked subjects to travel a given distance overground in a given allowed time duration. During this task, the subjects carried, and could look at, a stopwatch that counted down to zero. As expected, if the total time available were large, humans walk the whole distance. If the time available were small, humans mostly run. For an intermediate total time, humans often use a mixture of walking at a slow speed and running at a higher speed. With analytical and computational optimization, we show that using a walk–run mixture at intermediate speeds and a walk–rest mixture at the lowest average speeds is predicted by metabolic energy minimization, even with costs for transients—a consequence of non-convex energy curves. Thus, sometimes, steady locomotion may not be energy optimal, and not preferred, even in the absence of fatigue. Assuming similar non-convex energy curves, we conjecture that similar walk–run mixtures may be energetically beneficial to children following a parent and animals on long leashes. Humans and other animals might also benefit energetically from alternating between moving forward and standing still on a slow and sufficiently long treadmill. PMID:23365192

  17. 30 min of treadmill walking at self-selected speed does not increase gait variability in independent elderly.

    Science.gov (United States)

    Da Rocha, Emmanuel S; Kunzler, Marcos R; Bobbert, Maarten F; Duysens, Jacques; Carpes, Felipe P

    2018-06-01

    Walking is one of the preferred exercises among elderly, but could a prolonged walking increase gait variability, a risk factor for a fall in the elderly? Here we determine whether 30 min of treadmill walking increases coefficient of variation of gait in elderly. Because gait responses to exercise depend on fitness level, we included 15 sedentary and 15 active elderly. Sedentary participants preferred a lower gait speed and made smaller steps than the actives. Step length coefficient of variation decreased ~16.9% by the end of the exercise in both the groups. Stride length coefficient of variation decreased ~9% after 10 minutes of walking, and sedentary elderly showed a slightly larger step width coefficient of variation (~2%) at 10 min than active elderly. Active elderly showed higher walk ratio (step length/cadence) than sedentary in all times of walking, but the times did not differ in both the groups. In conclusion, treadmill gait kinematics differ between sedentary and active elderly, but changes over time are similar in sedentary and active elderly. As a practical implication, 30 min of walking might be a good strategy of exercise for elderly, independently of the fitness level, because it did not increase variability in step and stride kinematics, which is considered a risk of fall in this population.

  18. The effect of walking speed on hamstrings length and lengthening velocity in children with spastic cerebral palsy

    NARCIS (Netherlands)

    Krogt, van der M.M.; Doorenbosch, C.A.M.; Harlaar, J.

    2009-01-01

    0.001). These data are important as a reference for valid interpretation of hamstrings length and velocity data in gait analyses at different walking speeds. The results indicate that the presence of spasticity is associated with reduced hamstrings length and lengthening velocity during gait, even

  19. Reference values of maximum walking speed among independent community-dwelling Danish adults aged 60 to 79 years

    DEFF Research Database (Denmark)

    Tibaek, S; Holmestad-Bechmann, N; Pedersen, Trine B

    2015-01-01

    OBJECTIVES: To establish reference values for maximum walking speed over 10m for independent community-dwelling Danish adults, aged 60 to 79 years, and to evaluate the effects of gender and age. DESIGN: Cross-sectional study. SETTING: Danish companies and senior citizens clubs. PARTICIPANTS: Two ...

  20. Unstable footwear as a speed-dependent noise-based training gear to exercise inverted pendulum motion during walking.

    Science.gov (United States)

    Dierick, Frédéric; Bouché, Anne-France; Scohier, Mikaël; Guille, Clément; Buisseret, Fabien

    2018-05-15

    Previous research on unstable footwear has suggested that it may induce mechanical noise during walking. The purpose of this study was to explore whether unstable footwear could be considered as a noise-based training gear to exercise body center of mass (CoM) motion during walking. Ground reaction forces were collected among 24 healthy young women walking at speeds between 3 and 6 km h -1 with control running shoes and unstable rocker-bottom shoes. The external mechanical work, the recovery of mechanical energy of the CoM during and within the step cycles, and the phase shift between potential and kinetic energy curves of the CoM were computed. Our findings support the idea that unstable rocker-bottom footwear could serve as a speed-dependent noise-based training gear to exercise CoM motion during walking. At slow speed, it acts as a stochastic resonance or facilitator that reduces external mechanical work; whereas at brisk speed it acts as a constraint that increases external mechanical work and could mimic a downhill slope.

  1. Combined application of FBG and PZT sensors for plantar pressure monitoring at low and high speed walking.

    Science.gov (United States)

    Suresh, R; Bhalla, S; Singh, C; Kaur, N; Hao, J; Anand, S

    2015-01-01

    Clinical monitoring of planar pressure is vital in several pathological conditions, such as diabetes, where excess pressure might have serious repercussions on health of the patient, even to the extent of amputation. The main objective of this paper is to experimentally evaluate the combined application of the Fibre Bragg Grating (FBG) and the lead zirconate titanate (PZT) piezoceramic sensors for plantar pressure monitoring during walk at low and high speeds. For fabrication of the pressure sensors, the FBGs are embedded within layers of carbon composite material and stacked in an arc shape. From this embedding technique, average pressure sensitivity of 1.3 pm/kPa and resolution of nearly 0.8 kPa is obtained. These sensors are found to be suitable for measuring the static and the low-speed walk generated foot pressure. Simultaneously, PZT patches of size 10 × 10 × 0.3 mm were used as sensors, utilizing the d_{33} (thickness) coupling mode. A sensitivity of 7.06 mV/kPa and a pressure resolution of 0.14 kPa is obtained from these sensors, which are found to be suitable for foot pressure measurement during high speed walking and running. Both types of sensors are attached to the underside of the sole of commercially available shoes. In the experiments, a healthy male subject walks/runs over the treadmill wearing the fabricated shoes at various speeds and the peak pressure is measured using both the sensors. Commercially available low-cost hardware is used for interrogation of the two sensor types. The test results clearly show the feasibility of the FBG and the PZT sensors for measurement of plantar pressure. The PZT sensors are more accurate for measurement of pressure during walking at high speeds. The FBG sensors, on the other hand, are found to be suitable for static and quasi-dynamic (slow walking) conditions. Typically, the measured pressure varied from 400 to 600 kPa below the forefoot and 100 to 1000 kPa below the heel as the walking speed varied from 1

  2. Socioeconomic status, non-communicable disease risk factors, and walking speed in older adults: multi-cohort population based study.

    Science.gov (United States)

    Stringhini, Silvia; Carmeli, Cristian; Jokela, Markus; Avendaño, Mauricio; McCrory, Cathal; d'Errico, Angelo; Bochud, Murielle; Barros, Henrique; Costa, Giuseppe; Chadeau-Hyam, Marc; Delpierre, Cyrille; Gandini, Martina; Fraga, Silvia; Goldberg, Marcel; Giles, Graham G; Lassale, Camille; Kenny, Rose Anne; Kelly-Irving, Michelle; Paccaud, Fred; Layte, Richard; Muennig, Peter; Marmot, Michael G; Ribeiro, Ana Isabel; Severi, Gianluca; Steptoe, Andrew; Shipley, Martin J; Zins, Marie; Mackenbach, Johan P; Vineis, Paolo; Kivimäki, Mika

    2018-03-23

    To assess the association of low socioeconomic status and risk factors for non-communicable diseases (diabetes, high alcohol intake, high blood pressure, obesity, physical inactivity, smoking) with loss of physical functioning at older ages. Multi-cohort population based study. 37 cohort studies from 24 countries in Europe, the United States, Latin America, Africa, and Asia, 1990-2017. 109 107 men and women aged 45-90 years. Physical functioning assessed using the walking speed test, a valid index of overall functional capacity. Years of functioning lost was computed as a metric to quantify the difference in walking speed between those exposed and unexposed to low socioeconomic status and risk factors. According to mixed model estimations, men aged 60 and of low socioeconomic status had the same walking speed as men aged 66.6 of high socioeconomic status (years of functioning lost 6.6 years, 95% confidence interval 5.0 to 9.4). The years of functioning lost for women were 4.6 (3.6 to 6.2). In men and women, respectively, 5.7 (4.4 to 8.1) and 5.4 (4.3 to 7.3) years of functioning were lost by age 60 due to insufficient physical activity, 5.1 (3.9 to 7.0) and 7.5 (6.1 to 9.5) due to obesity, 2.3 (1.6 to 3.4) and 3.0 (2.3 to 4.0) due to hypertension, 5.6 (4.2 to 8.0) and 6.3 (4.9 to 8.4) due to diabetes, and 3.0 (2.2 to 4.3) and 0.7 (0.1 to 1.5) due to tobacco use. In analyses restricted to high income countries, the number of years of functioning lost attributable to low socioeconomic status by age 60 was 8.0 (5.7 to 13.1) for men and 5.4 (4.0 to 8.0) for women, whereas in low and middle income countries it was 2.6 (0.2 to 6.8) for men and 2.7 (1.0 to 5.5) for women. Within high income countries, the number of years of functioning lost attributable to low socioeconomic status by age 60 was greater in the United States than in Europe. Physical functioning continued to decline as a function of unfavourable risk factors between ages 60 and 85. Years of functioning

  3. A structural equation model of the relationship between muscle strength, balance performance, walking endurance and community integration in stroke survivors.

    Directory of Open Access Journals (Sweden)

    P W H Kwong

    Full Text Available To use structural equation modelling (SEM to determine (1 the direct and indirect associations of strength of paretic lower limb muscles with the level of community integration, and (2 the direct association of walking endurance and balance performance with the level of community integration in community-dwelling stroke survivors.In this cross-sectional study of 105 stroke survivors, the Subjective Index of Physical and Social Outcome (SIPSO was used to measure the level of community integration. Lower-limb strength measures included isometric paretic ankle strength and isokinetic paretic knee peak torque. The Berg Balance Scale (BBS and the 6-minute walk test (6MWT were used to evaluate balance performance and walking endurance, respectively.SEM revealed that the distance walked on the 6MWT had the strongest direct association with the SIPSO score (β = 0.41, p <0.001. An increase of one standard deviation in the 6MWT distance resulted in an increase of 0.41 standard deviations in the SIPSO score. Moreover, dorsiflexion strength (β = 0.18, p = 0.044 and the BBS score (β = 0.21, p = 0.021 had direct associations with the SIPSO score.The results of the proposed model suggest that rehabilitation training of community-dwelling stroke survivors could focus on walking endurance, balance performance and dorsiflexor muscle strengthening if the aim is to augment the level of community integration.

  4. Change of Direction Speed: Toward a Strength Training Approach with Accentuated Eccentric Muscle Actions.

    Science.gov (United States)

    Chaabene, Helmi; Prieske, Olaf; Negra, Yassine; Granacher, Urs

    2018-03-28

    There is growing evidence that eccentric strength training appears to have benefits over traditional strength training (i.e., strength training with combined concentric and eccentric muscle actions) from muscular, neuromuscular, tendinous, and metabolic perspectives. Eccentric muscle strength is particularly needed to decelerate and stabilize the body during the braking phase of a jump exercise or during rapid changes of direction (CoD) tasks. However, surprisingly little research has been conducted to elucidate the effects of eccentric strength training or strength training with accentuated eccentric muscle actions on CoD speed performance. In this current opinion article, we present findings from cross-sectional studies on the relationship between measures of eccentric muscle strength and CoD speed performance. In addition, we summarize the few available studies on the effects of strength training with accentuated eccentric muscle actions on CoD speed performance in athletic populations. Finally, we propose strength training with accentuated eccentric muscle actions as a promising element in strength and conditioning programs of sports with high CoD speed demands. Our findings from five cross-sectional studies revealed statistically significant moderate- to large-sized correlations (r = 0.45-0.89) between measures of eccentric muscle strength and CoD speed performance in athletic populations. The identified three intervention studies were of limited methodological quality and reported small- to large-sized effects (d = 0.46-1.31) of strength training with accentuated eccentric muscle actions on CoD speed performance in athletes. With reference to the available but preliminary literature and from a performance-related point of view, we recommend strength and conditioning coaches to include strength training with accentuated eccentric muscle actions in training routines of sports with high CoD speed demands (e.g., soccer, handball, basketball, hockey) to

  5. Exploring the Metabolic and Perceptual Correlates of Self-Selected Walking Speed under Constrained and Un-Constrained Conditions

    Directory of Open Access Journals (Sweden)

    David T Godsiff, Shelly Coe, Charlotte Elsworth-Edelsten, Johnny Collett, Ken Howells, Martyn Morris, Helen Dawes

    2018-03-01

    Full Text Available Mechanisms underpinning self-selected walking speed (SSWS are poorly understood. The present study investigated the extent to which SSWS is related to metabolism, energy cost, and/or perceptual parameters during both normal and artificially constrained walking. Fourteen participants with no pathology affecting gait were tested under standard conditions. Subjects walked on a motorized treadmill at speeds derived from their SSWS as a continuous protocol. RPE scores (CR10 and expired air to calculate energy cost (J.kg-1.m-1 and carbohydrate (CHO oxidation rate (J.kg-1.min-1 were collected during minutes 3-4 at each speed. Eight individuals were re-tested under the same conditions within one week with a hip and knee-brace to immobilize their right leg. Deflection in RPE scores (CR10 and CHO oxidation rate (J.kg-1.min-1 were not related to SSWS (five and three people had deflections in the defined range of SSWS in constrained and unconstrained conditions, respectively (p > 0.05. Constrained walking elicited a higher energy cost (J.kg-1.m-1 and slower SSWS (p 0.05. SSWS did not occur at a minimum energy cost (J.kg-1.m-1 in either condition, however, the size of the minimum energy cost to SSWS disparity was the same (Froude {Fr} = 0.09 in both conditions (p = 0.36. Perceptions of exertion can modify walking patterns and therefore SSWS and metabolism/ energy cost are not directly related. Strategies which minimize perceived exertion may enable faster walking in people with altered gait as our findings indicate they should self-optimize to the same extent under different conditions.

  6. Therapeutic effects of maximal strength training on walking efficiency in patients with schizophrenia - a pilot study.

    Science.gov (United States)

    Heggelund, Jørn; Morken, Gunnar; Helgerud, Jan; Nilsberg, Geir E; Hoff, Jan

    2012-07-03

    Patients with schizophrenia frequently have disabling gait deficits. The net mechanical efficiency of walking (ϵnet) is an accurate measure often used to evaluate walking performance. Patients with gait deficits have a reduced ϵnet with excessive energy expenditure during sub-maximal walking. Maximal strength training (MST) improves ϵnet in healthy individuals and is associated with reduced risk of mortality. The aim of this study was to investigate whether MST improves ϵnet in patients with schizophrenia. Patients (ICD-10 schizophrenia, schizotypal or delusional disorders (F20-F29)) were included in a non-randomized trial. Patients were assigned to one of two groups: 1) MST consisting of 4x4 repetitions at 85-90% one repetition maximum (1RM) performed in a leg press apparatus or 2) playing computer games (CG). Both groups carried out their activity three days per week for eight weeks. 1RM, ϵnet at 60 watt walking, peak oxygen uptake (VO2peak), the Positive and Negative Syndrome Scale (PANSS) and the 36-items short form (SF-36) were measured pre and post intervention. The baseline ϵnet was 17.3 ± 1.2% and 19.4 ± 3.0% in the MST (n = 6) and CG groups (n = 7), respectively, which is categorized as mechanical inefficiency. The MST group improved 1RM by 79 kg (p = 0.006) and ϵnet by 3.4% (p = 0.046) more than the CG group. The MST group improved 1RM and ϵnet, by a mean of 83 kg (p = 0.028) and 3.4% (p = 0.028), respectively. VO2peak at baseline was 34.2 ± 10.2 and 38.3 ± 9.8 ml·kg-1·min-1 in the MST and CG groups, respectively, and did not change (p > 0.05). No change was observed in PANSS or SF-36 (p > 0.05). MST improves 1RM and ϵnet in patients with schizophrenia. MST could be used as a therapeutic intervention for patients with schizophrenia to normalize their reduced ϵnet.

  7. Development and validation of a new method to measure walking speed in free-living environments using the actibelt® platform.

    Directory of Open Access Journals (Sweden)

    Michaela Schimpl

    Full Text Available Walking speed is a fundamental indicator for human well-being. In a clinical setting, walking speed is typically measured by means of walking tests using different protocols. However, walking speed obtained in this way is unlikely to be representative of the conditions in a free-living environment. Recently, mobile accelerometry has opened up the possibility to extract walking speed from long-time observations in free-living individuals, but the validity of these measurements needs to be determined. In this investigation, we have developed algorithms for walking speed prediction based on 3D accelerometry data (actibelt® and created a framework using a standardized data set with gold standard annotations to facilitate the validation and comparison of these algorithms. For this purpose 17 healthy subjects operated a newly developed mobile gold standard while walking/running on an indoor track. Subsequently, the validity of 12 candidate algorithms for walking speed prediction ranging from well-known simple approaches like combining step length with frequency to more sophisticated algorithms such as linear and non-linear models was assessed using statistical measures. As a result, a novel algorithm employing support vector regression was found to perform best with a concordance correlation coefficient of 0.93 (95%CI 0.92-0.94 and a coverage probability CP1 of 0.46 (95%CI 0.12-0.70 for a deviation of 0.1 m/s (CP2 0.78, CP3 0.94 when compared to the mobile gold standard while walking indoors. A smaller outdoor experiment confirmed those results with even better coverage probability. We conclude that walking speed thus obtained has the potential to help establish walking speed in free-living environments as a patient-oriented outcome measure.

  8. Relationship between strength qualities and short track speed skating performance in young athletes.

    Science.gov (United States)

    Felser, S; Behrens, M; Fischer, S; Heise, S; Bäumler, M; Salomon, R; Bruhn, S

    2016-02-01

    This study analyzed the relationships between isometric as well as concentric maximum voluntary contraction (MVC) strength of the leg muscles and the times as well as speeds over different distances in 17 young short track speed skaters. Isometric as well as concentric single-joint MVC strength and multi-joint MVC strength in a stable (without skates) and unstable (with skates) condition were tested. Furthermore, time during maximum skating performances on ice was measured. Results indicate that maximum torques during eversion and dorsal flexion have a significant influence on skating speed. Concentric MVC strength of the knee extensors was higher correlated with times as well as speeds over the different distances than isometric MVC strength. Multi-joint MVC testing revealed that the force loss between measurements without and with skates amounts to 25%, while biceps femoris and soleus showed decreased muscle activity and peroneus longus, tibialis anterior, as well as rectus femoris exhibited increased muscle activity. The results of this study depict evidence that the skating times and speeds are primarily influenced by concentric MVC strength of the leg extensors. To be able to transfer the strength onto ice in an optimal way, it is necessary to stabilize the knee and ankle joints. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. The preferred walk to run transition speed in actual lunar gravity.

    Science.gov (United States)

    De Witt, John K; Edwards, W Brent; Scott-Pandorf, Melissa M; Norcross, Jason R; Gernhardt, Michael L

    2014-09-15

    Quantifying the preferred transition speed (PTS) from walking to running has provided insight into the underlying mechanics of locomotion. The dynamic similarity hypothesis suggests that the PTS should occur at the same Froude number across gravitational environments. In normal Earth gravity, the PTS occurs at a Froude number of 0.5 in adult humans, but previous reports found the PTS occurred at Froude numbers greater than 0.5 in simulated lunar gravity. Our purpose was to (1) determine the Froude number at the PTS in actual lunar gravity during parabolic flight and (2) compare it with the Froude number at the PTS in simulated lunar gravity during overhead suspension. We observed that Froude numbers at the PTS in actual lunar gravity (1.39±0.45) and simulated lunar gravity (1.11±0.26) were much greater than 0.5. Froude numbers at the PTS above 1.0 suggest that the use of the inverted pendulum model may not necessarily be valid in actual lunar gravity and that earlier findings in simulated reduced gravity are more accurate than previously thought. © 2014. Published by The Company of Biologists Ltd.

  10. Speed and Duration of Walking and Other Leisure Time Physical Activity and the Risk of Heart Failure

    DEFF Research Database (Denmark)

    Sævereid, Hans Askelund; Schnohr, Peter; Prescott, Eva

    2014-01-01

    in 1976-2003, we studied the association between updated self-assessed leisure-time PA, speed and duration of walking and subsequent hospitalization or death from HF. Light and moderate/high level of leisure-time PA and brisk walking were associated with reduced risk of HF in both genders whereas...... no consistent association with duration of walking was seen. In 18,209 subjects age 20-80 with 1580 cases of HF, using the lowest activity level as reference, the confounder-adjusted hazard ratios (HR) for light and moderate/high leisure-time physical activity were 0.75 (0.66-0.86) and 0.80 (0......-spread PA and public health measures to curb the increase in HF may benefit from this information....

  11. A clinically meaningful training effect in walking speed using functional electrical stimulation for motor-incomplete spinal cord injury.

    Science.gov (United States)

    Street, Tamsyn; Singleton, Christine

    2018-05-01

    The study aimed to investigate the presence of a training effect for rehabilitation of walking function in motor-incomplete spinal cord injury (SCI) through daily use of functional electrical stimulation (FES). A specialist FES outpatient centre. Thirty-five participants (mean age 53, SD 15, range 18-80; mean years since diagnosis 9, range 5 months - 39 years) with drop foot and motor-incomplete SCI (T12 or higher, ASIA Impairment Scale C and D) able to ambulate 10 metres with the use of a walking stick or frame. FES of the peroneal nerve, glutei and hamstrings as clinically indicated over six months in the community. The data was analysed for a training effect (difference between unassisted ten metre walking speed at baseline and after six months) and orthotic effects (difference between walking speed with and without FES) initially on day one and after six months. The data was further analysed for a minimum clinically important difference (MCID) (>0.06 m/s). A clinically meaningful, significant change was observed for initial orthotic effect (0.13m/s, CI: 0.04-0.17, P = 0.013), total orthotic effect (0.11m/s, CI: 0.04-0.18, P = 0.017) and training effect (0.09m/s, CI: 0.02-0.16, P = 0.025). The results suggest that daily independent use of FES may produce clinically meaningful changes in walking speed which are significant for motor-incomplete SCI. Further research exploring the mechanism for the presence of a training effect may be beneficial in targeting therapies for future rehabilitation.

  12. Explosive strength training improves speed and agility in wheelchair basketball athletes

    Directory of Open Access Journals (Sweden)

    Tarik Ozmen

    2014-04-01

    Full Text Available INTRODUCTION: Wheelchair basketball is a paralympic sport characterized by intermittent high-intensity activities that require explosive strength and speed. OBJECTIVE: To investigate the effect of explosive strength training on speed and agility performance in wheelchair basketball players. METHODS: Ten male wheelchair basketball players (Mage=31±4 yrs were divided into two groups [i.e. explosive strength training (ES; control (CN] based on International Wheelchair Basketball Federation (IWBF classification scores. The ES group underwent 6-weeks of training, twice weekly, at 50% 1RM, 10-12 repetitions and 3-4 sets in addition to routine training. Effects of training were measured by the 20 m sprint test and Illinois agility test. RESULTS: The ES group, showed significantly higher increases in speed and agility performance (p ≤ .05. CONCLUSION: A short-duration (i.e. 6-week explosive strength training programme in wheelchair basketball athletes results in significant improvements in sprint and agility performance.

  13. Does walking speed mediate the association between visual impairment and self-report of mobility disability? The Salisbury Eye Evaluation Study.

    Science.gov (United States)

    Swenor, Bonnielin K; Bandeen-Roche, Karen; Muñoz, Beatriz; West, Sheila K

    2014-08-01

    To determine whether performance speeds mediate the association between visual impairment and self-reported mobility disability over an 8-year period. Longitudinal analysis. Salisbury, Maryland. Salisbury Eye Evaluation Study participants aged 65 and older (N=2,520). Visual impairment was defined as best-corrected visual acuity worse than 20/40 in the better-seeing eye or visual field less than 20°. Self-reported mobility disability on three tasks was assessed: walking up stairs, walking down stairs, and walking 150 feet. Performance speed on three similar tasks was measured: walking up steps (steps/s), walking down steps (steps/s), and walking 4 m (m/s). For each year of observation, the odds of reporting mobility disability was significantly greater for participants who were visually impaired (VI) than for those who were not (NVI) (odds ratio (OR) difficulty walking up steps=1.58, 95% confidence interval (CI)=1.32-1.89; OR difficulty walking down steps=1.90, 95% CI=1.59-2.28; OR difficulty walking 150 feet=2.11, 95% CI=1.77-2.51). Once performance speed on a similar mobility task was included in the models, VI participants were no longer more likely to report mobility disability than those who were NVI (OR difficulty walking up steps=0.84, 95% CI=0.65-1.11; OR difficulty walking down steps=0.96, 95% CI=0.74-1.24; OR difficulty walking 150 feet=1.22, 95% CI=0.98-1.50). Slower performance speed in VI individuals largely accounted for the difference in the odds of reporting mobility disability, suggesting that VI older adults walk slower and are therefore more likely to report mobility disability than those who are NVI. Improving mobility performance in older adults with visual impairment may minimize the perception of mobility disability. © 2014, Copyright the Authors Journal compilation © 2014, The American Geriatrics Society.

  14. Mechanical and neural stretch responses of the human soleus muscle at different walking speeds

    DEFF Research Database (Denmark)

    Cronin, Neil J; Ishikawa, Masaki; Grey, Michael J

    2009-01-01

    responses. Twelve healthy subjects walked on a treadmill with the left leg attached to an actuator capable of rapidly dorsiflexing the ankle joint. Ultrasound was used to measure fascicle lengths in SOL during walking, and surface electromyography (EMG) was used to record muscle activation. Dorsiflexion...

  15. Is Walking Capacity in Subjects with Multiple Sclerosis Primarily Related to Muscle Oxidative Capacity or Maximal Muscle Strength? A Pilot Study

    Directory of Open Access Journals (Sweden)

    Dominique Hansen

    2014-01-01

    Full Text Available Background and Purpose. Walking capacity is reduced in subjects with multiple sclerosis (MS. To develop effective exercise interventions to enhance walking capacity, it is important to determine the impact of factors, modifiable by exercise intervention (maximal muscle strength versus muscle oxidative capacity, on walking capacity. The purpose of this pilot study is to discriminate between the impact of maximal muscle strength versus muscle oxidative capacity on walking capacity in subjects with MS. Methods. From 24 patients with MS, muscle oxidative capacity was determined by calculation of exercise-onset oxygen uptake kinetics (mean response time during submaximal exercise bouts. Maximal muscle strength (isometric knee extension and flexion peak torque was assessed on dynamometer. All subjects completed a 6-minute walking test. Relationships between walking capacity (as a percentage of normal value and muscle strength (of knee flexors and extensors versus muscle oxidative capacity were assessed in multivariate regression analyses. Results. The expanded disability status score (EDSS showed a significant univariate correlation (r=-0.70, P<0.004 with walking capacity. In multivariate regression analyses, EDSS and mean response time, but not muscle strength, were independently related to walking capacity (P<0.05. Conclusions. Walking distance is, next to disability level and not taking neurologic symptoms/deficits into account, primarily related to muscle oxidative capacity in subjects with MS. Additional study is needed to further examine/verify these findings.

  16. Locomotion Mode Affects the Physiological Strain during Exercise at Walk-Run Transition Speed inElderly Men.

    Science.gov (United States)

    Freire, Raul; Farinatti, Paulo; Cunha, Felipe; Silva, Brenno; Monteiro, Walace

    2017-07-01

    This study investigated cardiorespiratory responses and rating of perceived exertion (RPE) during prolonged walking and running exercise performed at the walk-run transition speed (WRTS) in untrained healthy elderly men. 20 volunteers (mean±SE, age: 68.4±1.2 yrs; height: 170.0±0.02 cm; body mass: 74.7±2.3 kg) performed the following bouts of exercise: a) maximal cardiopulmonary exercise test (CPET); b) specific protocol to detect WRTS; and c) two 30-min walking and running bouts at WRTS. Expired gases were collected during exercise bouts via the Ultima CardiO 2 metabolic analyzer. Compared to walking, running at the WRTS resulted in higher oxygen uptake (>0.27 L·min -1 ), pulmonary ventilation (>7.7 L·min -1 ), carbon dioxide output (>0.23 L·min -1 ), heart rate (>15 beats·min -1 ), oxygen pulse (>0.88 15 mL·beats -1 ), energy expenditure (>27 kcal) and cost of oxygen transport (>43 mL·kg -1 ·km -1 ·bout -1 ). The increase of overall and local RPEs with exercise duration was similar across locomotion modes (Pexercise tolerance. © Georg Thieme Verlag KG Stuttgart · New York.

  17. Race Differences: Use of Walking Speed to Identify Community-Dwelling Women at Risk for Poor Health Outcomes--Osteoarthritis Initiative Study.

    Science.gov (United States)

    Kirkness, Carmen S; Ren, Jinma

    2015-07-01

    Onset of disability, risk for future falls, frailty, functional decline, and mortality are strongly associated with a walking speed of less than 1.0 m/s. The study objective was to determine whether there were differences in slow walking speed (differences in walking speed can be attributed to age, obesity, socioeconomic factors, disease severity, or comorbidities. A cross-sectional design was used. Community-dwelling adults were recruited from Baltimore, Maryland; Columbus, Ohio; Pittsburgh, Pennsylvania; and Pawtucket, Rhode Island. Participants were 2,648 women (23% African American) who were 45 to 79 years of age and had a self-selected baseline walking speed of 20 m/s in the Osteoarthritis Initiative Study. Mixed-effects logistic regression models were used to examine racial differences in walking speed (<1.0 m/s versus ≥1.0 m/s), with adjustments for demographic factors, socioeconomic factors, disease severity, and comorbidities. Walking speed was significantly slower for African American women than for white American women (mean walking speed=1.19 and 1.33 m/s, respectively). The prevalence of a walking speed of less than 1.0 m/s in this cohort of middle-aged women was 9%; about 50% of the women with a walking speed of less than 1.0 m/s were younger than 65 years. Women with a walking speed of less than 1.0 m/s had lower values for socioeconomic factors, higher values for disease severity, and higher prevalences of obesity and comorbidities than those with a walking speed of ≥1.0 m/s. After controlling for these covariates, it was found that African American women were 3 times (odds ratio=2.9; 95% confidence interval=2.0, 4.1) more likely to have a walking speed of less than 1.0 m/s than white American women. The study design made it impossible to know whether a walking speed of less than 1.0 m/s in women who were 45 years of age or older was a predictor of future poor health outcomes. In this study, race was independently associated with a walking speed

  18. Muscle function-dependent sarcopenia and cut-off values of possible predictors in community-dwelling Turkish elderly: calf circumference, midarm muscle circumference and walking speed.

    Science.gov (United States)

    Akın, S; Mucuk, S; Öztürk, A; Mazıcıoğlu, M; Göçer, Ş; Arguvanlı, S; Şafak, E D

    2015-10-01

    The aim of this study was to determine the prevalence of muscle strength-based sarcopenia and to determine possible predictors. This is a cross-sectional population-based study in the community-dwelling Turkish elderly. Anthropometric measurements, namely body height, weight, triceps skin fold (TSF), mid upper arm circumference (MUAC), waist circumference (WC) and calf circumference (CC), were noted. The midarm muscle circumference (MAMC) was calculated by using MUAC and TSF measurement. Sarcopenia was assessed, adjusted for body mass index (BMI) and gender, according to muscle strength. Physical performance was determined by 4 m walking speed (WS; m/s). The receiver operating curve analysis was performed to determine cut-offs of CC, MAMC and 4 m WS. A total of 879 elderly subjects, 50.1% of whom were female, were recruited. The mean handgrip strength (HGS) and s.d. was 24.2 (8.8) kg [17.9 (4.8) female, 30.6 (7.1) male]. The muscle function-dependent sarcopenia was 63.4% (female 73.5%, male 53.2%). The muscle mass-dependent sarcopenia for CC (sarcopenia. An adequate muscle mass may not mean a reliable muscle function. Muscle function may describe sarcopenia better compared with muscle mass. The CC, MAMC and 4 m WS cut-offs may be used to assess sarcopenia in certain age groups.

  19. Comparison of Speed, Agility, Anaerobic Strength and Anthropometric Characteristics in Male Football and Futsal Players

    Science.gov (United States)

    Kartal, Resat

    2016-01-01

    The purpose of this study is to compare speed, agility, anaerobic strength and some anthropometric characteristics in male football and futsal players. The sample of the study is composed of male futsal team players of Aydin Adnan Menderes University (19-24 aged) (n = 12) and Aydin Merkez Yeniköy Football Club players (19-24 aged) (n = 12). Within…

  20. Strength, running speed, agility and balance profiles of 9- to 10-year ...

    African Journals Online (AJOL)

    The purpose of this study was to determine the strength, running speed and agility, and balance profiles of 9- to 10-year old learners and the relation between these skills of the learners. Using a stratified random selection from 20 schools with different socio-economic backgrounds, 862 9- to 10-year-old learners (457 boys; ...

  1. Speed-strength abilities and morphological characteristics of basketball players aged 10 and 11

    Directory of Open Access Journals (Sweden)

    Đorđević Alen

    2016-01-01

    Full Text Available The aim of this study was to identify several morphological characteristics and speed-strength abilities in basketball players aged 10 and 11, and to determine possible differences between them, connected with their age. The research was conducted on a sample of 84 young basketball players aged 10 (N=46 and 11 (N=38. The following motor variables were measured: shoulder explosiveness (throwing the ball from basketball position, leg explosiveness (vertical jump, speed strength of the trunk (sit up exercises in 10 seconds, stamina in speed strength of the trunk (sit up exercises in 30 seconds, the speed of changing the direction of moving (agility T-test, acceleration (running for 5 and 20 meters. The following morphological variables were also measured: body height, body mass, percentage of body fat and percentage of muscle tissue. Eleven-year-olds achieved better results than the ten-year-olds in all categories. Statistically significant differences (p<0.01 between the two groups of subjects were found in body height, percentage of muscle tissue in the body, shoulder explosiveness, as well as in the speed of changing the direction of moving. Differences in body mass and ability for acceleration were found on the level of statistical significance (p<0.05.

  2. Increasing FSW join strength by optimizing feed rate, rotating speed and pin angle

    Science.gov (United States)

    Darmadi, Djarot B.; Purnowidodo, Anindito; Siswanto, Eko

    2017-10-01

    Principally the join in Friction Stir Welding (FSW) is formed due to mechanical bonding. At least there are two factors determines the quality of this join, first is the temperature in the area around the interface and secondly the intense of mixing forces in nugget zone to create the mechanical bonding. The adequate temperature creates good flowability of the nugget zone and an intensive mixing force produces homogeneous strong bonding. Based on those two factors in this research the effects of feed rate, rotating speed and pin angle of the FSW process to the tensile strength of resulted join are studied. The true experimental method was used. Feed rate was varied at 24, 42, 55 and 74 mm/minutes and from the experimental results, it can be concluded that the higher feed rate decreases the tensile strength of weld join and it is believed due to the lower heat embedded in the material. Inversely, the higher rotating speed increases the join’s tensile strength as a result of higher heat embedded in base metal and higher mixing force in the nugget zone. The rotating speed were 1842, 2257 and 2904 RPMs. The pin angle determines the direction of mixing force. With variation of pin angle: 0°, 4°, 8° and 12° the higher pin angle generally increases the tensile strength because of more intensive mixing force. For 12° pin angle the lower tensile strength is found since the force tends to push out the nugget area from the joint gap.

  3. Healthy older adults have insufficient hip range of motion and plantar flexor strength to walk like healthy young adults.

    Science.gov (United States)

    Anderson, Dennis E; Madigan, Michael L

    2014-03-21

    Limited plantar flexor strength and hip extension range of motion (ROM) in older adults are believed to underlie common age-related differences in gait. However, no studies of age-related differences in gait have quantified the percentage of strength and ROM used during gait. We examined peak hip angles, hip torques and plantar flexor torques, and corresponding estimates of functional capacity utilized (FCU), which we define as the percentage of available strength or joint ROM used, in 10 young and 10 older healthy adults walking under self-selected and controlled (slow and fast) conditions. Older adults walked with about 30% smaller hip extension angle, 28% larger hip flexion angle, 34% more hip extensor torque in the slow condition, and 12% less plantar flexor torque in the fast condition than young adults. Older adults had higher FCU than young adults for hip flexion angle (47% vs. 34%) and hip extensor torque (48% vs. 27%). FCUs for plantar flexor torque (both age groups) and hip extension angle (older adults in all conditions; young adults in self-selected gait) were not significantly adults lacked sufficient hip extension ROM to walk with a hip extension angle as large as that of young adults. Similarly, in the fast gait condition older adults lacked the strength to match the plantar flexor torque produced by young adults. This supports the hypothesis that hip extension ROM and plantar flexor strength are limiting factors in gait and contribute to age-related differences in gait. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Step-by-step variability of swing phase trajectory area during steady state walking at a range of speeds

    Science.gov (United States)

    Hurt, Christopher P.; Brown, David A.

    2018-01-01

    Background Step kinematic variability has been characterized during gait using spatial and temporal kinematic characteristics. However, people can adopt different trajectory paths both between individuals and even within individuals at different speeds. Single point measures such as minimum toe clearance (MTC) and step length (SL) do not necessarily account for the multiple paths that the foot may take during the swing phase to reach the same foot fall endpoint. The purpose of this study was to test a step-by-step foot trajectory area (SBS-FTA) variability measure that is able to characterize sagittal plane foot trajectories of varying areas, and compare this measure against MTC and SL variability at different speeds. We hypothesize that the SBS-FTA variability would demonstrate increased variability with speed. Second, we hypothesize that SBS-FTA would have a stronger curvilinear fit compared with the CV and SD of SL and MTC. Third, we hypothesize SBS-FTA would be more responsive to change in the foot trajectory at a given speed compared to SL and MTC. Fourth, SBS-FTA variability would not strongly co-vary with SL and MTC variability measures since it represents a different construct related to foot trajectory area variability. Methods We studied 15 nonimpaired individuals during walking at progressively faster speeds. We calculated SL, MTC, and SBS-FTA area. Results SBS-FTA variability increased with speed, had a stronger curvilinear fit compared with the CV and SD of SL and MTC, was more responsive at a given speed, and did not strongly co-vary with SL and MTC variability measures. Conclusion SBS foot trajectory area variability was sensitive to change with faster speeds, captured a relationship that the majority of the other measures did not demonstrate, and did not co-vary strongly with other measures that are also components of the trajectory. PMID:29370202

  5. The adaptation of limb kinematics to increasing walking speeds in freely moving mice 129/Sv and C57BL/6.

    Science.gov (United States)

    Serradj, Nadjet; Jamon, Marc

    2009-07-19

    The kinematics of locomotion was analyzed in two strains of great importance for the creation of mutated mice (C56BL/6 and 129/Sv). Different behavioral situations were used to trigger sequences of movement covering the whole range of velocities in the mice, and the variations of kinematic parameters were analyzed in relation with velocity. Both stride frequency and stride length contributed to the moving speed, but stride frequency was found to be the main contributor to the speed increase. A trot-gallop transition was detected at speed about 70 cm/s, in relation with a sharp shift in limb coordination. The results of this study were consistent with pieces of information previously published concerning the gait analyses of other strains, and provided an integrative view of the basic motor pattern of mice. On the other hand some qualitative differences were found in the movement characteristics of the two strains. The stride frequency showed a higher contribution to speed in 129/Sv than in C57BL/6. In addition, 129/Sv showed a phase shift in the forelimb and hindlimb, and a different position of the foot during the stance time that revealed a different gait and body position during walking. Overall, 129/Sv moved at a slower speed than C57BL/6 in any behavioral situation. This difference was related to a basal lower level of motor activity. The possibility that an alteration in the dopamine circuit was responsible for the different movement pattern in 129/Sv is discussed.

  6. Quadriceps strength, quadriceps power, and gait speed in older U.S. adults with diabetes mellitus: results from the National Health and Nutrition Examination Survey, 1999-2002.

    Science.gov (United States)

    Kalyani, Rita Rastogi; Tra, Yolande; Yeh, Hsin-Chieh; Egan, Josephine M; Ferrucci, Luigi; Brancati, Frederick L

    2013-05-01

    To examine the independent association between diabetes mellitus (and its duration and severity) and quadriceps strength, quadriceps power, and gait speed in a national population of older adults. Cross-sectional nationally representative survey. United States. Two thousand five hundred seventy-three adults aged 50 and older in the National Health and Nutrition Examination Survey 1999-2002 who had assessment of quadriceps strength. Diabetes mellitus was ascertained according to questionnaire. Measurement of isokinetic knee extensor (quadriceps) strength was performed at 60º/s. Gait speed was assessed using a 20-foot walk test. Multiple linear regression analyses were used to assess the association between diabetes mellitus status and outcomes, adjusting for potential confounders or mediators. Older U.S. adults with diabetes mellitus had significantly slower gait speed (0.96 ± 0.02 m/s) than those without (1.08 ± 0.01 m/s; P diabetes mellitus was also associated with significantly lower quadriceps strength (-4.6 ± 1.9 Nm; P = .02) and power (-4.9 ± 2.0 W; P = .02) and slower gait speed (-0.05 ± 0.02 m/s; P = .002). Associations remained significant after adjusting for physical activity and C-reactive protein. After accounting for comorbidities (cardiovascular disease, peripheral neuropathy, amputation, cancer, arthritis, fracture, chronic obstructive pulmonary disease), diabetes mellitus was independently associated only with gait speed (-0.04 ± 0.02 m/s; P = .02). Diabetes mellitus duration in men and women was negatively associated with age-adjusted quadriceps strength (-5.7 and -3.5 Nm/decade of diabetes mellitus, respectively) and power (-6.1 and -3.8 W/decade of diabetes mellitus, respectively) (all P ≤ .001, no significant interactions according to sex). Glycosylated hemoglobin was not associated with outcomes after accounting for body weight. Older U.S. adults with diabetes mellitus have lower quadriceps strength and quadriceps power that is related

  7. Control entropy identifies differential changes in complexity of walking and running gait patterns with increasing speed in highly trained runners.

    Science.gov (United States)

    McGregor, Stephen J; Busa, Michael A; Skufca, Joseph; Yaggie, James A; Bollt, Erik M

    2009-06-01

    Regularity statistics have been previously applied to walking gait measures in the hope of gaining insight into the complexity of gait under different conditions and in different populations. Traditional regularity statistics are subject to the requirement of stationarity, a limitation for examining changes in complexity under dynamic conditions such as exhaustive exercise. Using a novel measure, control entropy (CE), applied to triaxial continuous accelerometry, we report changes in complexity of walking and running during increasing speeds up to exhaustion in highly trained runners. We further apply Karhunen-Loeve analysis in a new and novel way to the patterns of CE responses in each of the three axes to identify dominant modes of CE responses in the vertical, mediolateral, and anterior/posterior planes. The differential CE responses observed between the different axes in this select population provide insight into the constraints of walking and running in those who may have optimized locomotion. Future comparisons between athletes, healthy untrained, and clinical populations using this approach may help elucidate differences between optimized and diseased locomotor control.

  8. Does manipulating the speed of visual flow in virtual reality change distance estimation while walking in Parkinson's disease?

    Science.gov (United States)

    Ehgoetz Martens, Kaylena A; Ellard, Colin G; Almeida, Quincy J

    2015-03-01

    Although dopaminergic replacement therapy is believed to improve sensory processing in PD, while delayed perceptual speed is thought to be caused by a predominantly cholinergic deficit, it is unclear whether sensory-perceptual deficits are a result of corrupt sensory processing, or a delay in updating perceived feedback during movement. The current study aimed to examine these two hypotheses by manipulating visual flow speed and dopaminergic medication to examine which influenced distance estimation in PD. Fourteen PD and sixteen HC participants were instructed to estimate the distance of a remembered target by walking to the position the target formerly occupied. This task was completed in virtual reality in order to manipulate the visual flow (VF) speed in real time. Three conditions were carried out: (1) BASELINE: VF speed was equal to participants' real-time movement speed; (2) SLOW: VF speed was reduced by 50 %; (2) FAST: VF speed was increased by 30 %. Individuals with PD performed the experiment in their ON and OFF state. PD demonstrated significantly greater judgement error during BASELINE and FAST conditions compared to HC, although PD did not improve their judgement error during the SLOW condition. Additionally, PD had greater variable error during baseline compared to HC; however, during the SLOW conditions, PD had significantly less variable error compared to baseline and similar variable error to HC participants. Overall, dopaminergic medication did not significantly influence judgement error. Therefore, these results suggest that corrupt processing of sensory information is the main contributor to sensory-perceptual deficits during movement in PD rather than delayed updating of sensory feedback.

  9. Relationship between strength, power, speed, and change of direction performance of female softball players.

    Science.gov (United States)

    Nimphius, Sophia; McGuigan, Michael R; Newton, Robert U

    2010-04-01

    The purpose of this study was to investigate (a) the cross-sectional relationship of strength, power, and performance variables in trained female athletes and (b) determine if the relationship between these variables changes over the course of a season. Ten female softball players (age = 18.1 +/- 1.6 years, height = 166.5 +/- 8.9 cm, and weight = 72.4 +/- 10.8 kg) from a state Australian Institute of Sport softball team were tested for maximal lower body strength (one repetition maximum [1RM]), peak force (PF), peak velocity (PV), and peak power (PP) during jump squats unloaded and loaded, unloaded countermovement vertical jump height (VJH) 1 base and 2 base sprint performance and change of direction performance on dominant and nondominant sides. The testing sessions occurred pre, mid, and post a 20-week training period. Relationship between body weight (BW), relative strength (1RM/BW), VJH, relative PP, relative PF, PV, speed, and change of direction variables were assessed by Pearson product-moment correlation coefficient at each testing session. Significant relationships were found across all time points with BW, speed, and change of direction measures (r = 0.70-0.93) and relative strength and measures of speed and change of direction ability (r = -0.73-0.85). There were no significant relationships between VJH and any measure of performance at any time point. In conclusion, BW and relative strength have strong to very strong correlations with speed and change of direction ability, and these correlations remain consistent over the course of the season. However, it seems as if many relationships vary with time, and their relationships should therefore be investigated longitudinally to better determine if these cross-sectional relationships truly reflect a deterministic relationship.

  10. Age differences in the required coefficient of friction during level walking do not exist when experimentally-controlling speed and step length.

    Science.gov (United States)

    Anderson, Dennis E; Franck, Christopher T; Madigan, Michael L

    2014-08-01

    The effects of gait speed and step length on the required coefficient of friction (COF) confound the investigation of age-related differences in required COF. The goals of this study were to investigate whether age differences in required COF during self-selected gait persist when experimentally-controlling speed and step length, and to determine the independent effects of speed and step length on required COF. Ten young and 10 older healthy adults performed gait trials under five gait conditions: self-selected, slow and fast speeds without controlling step length, and slow and fast speeds while controlling step length. During self-selected gait, older adults walked with shorter step lengths and exhibited a lower required COF. Older adults also exhibited a lower required COF when walking at a controlled speed without controlling step length. When both age groups walked with the same speed and step length, no age difference in required COF was found. Thus, speed and step length can have a large influence on studies investigating age-related differences in required COF. It was also found that speed and step length have independent and opposite effects on required COF, with step length having a strong positive effect on required COF, and speed having a weaker negative effect.

  11. A community-based Falls Management Exercise Programme (FaME) improves balance, walking speed and reduced fear of falling.

    Science.gov (United States)

    Yeung, Pui Yee; Chan, Wayne; Woo, Jean

    2015-04-01

    Although effective community falls prevention programmes for the older persons have been described, challenges remain in translating proven interventions into daily practice. To evaluate the efficacy, feasibility and acceptability of a falls prevention programme that can be integrated into daily activities in a group of community-dwelling older adults with risk of falling. A cohort study with intervention and comparison groups was designed to evaluate a 36-week group-based falls prevention exercise programme (FaME) in the community setting. Participants were aged 60 years or older, had fallen in the past 12 months, had fear of falling with avoidance of activities or had deficits in balance control. Primary outcome measures included assessment of balance control and mobility; secondary outcome measures included level of physical activity, assessment of fear of falling and health-related quality of life. There were 48 and 51 participants in the intervention and comparison groups, respectively. There were improvements in measurements of balance, walking speed and self-efficacy. The drop out rate was low (14.6% and 3.9% from the intervention and comparison groups, respectively). Overall compliance in the intervention group was 79%. Factors that motivated continued participation include the regular and long-term nature of the programme helping to reinforce their exercise habits, the simplicity of movements and friendliness of the group. The FaME programme improves balance, walking speed and reduces fear of falling. It could be widely promoted and integrated into regular health and social activities in community settings.

  12. In hip osteoarthritis, Nordic Walking is superior to strength training and home based exercise for improving function

    DEFF Research Database (Denmark)

    Bieler, T.; Siersma, Volkert; Magnusson, S. P.

    2017-01-01

    in 60+-year-old persons (n = 152) with hip osteoarthritis (OA) not awaiting hip replacement. Functional performance [i.e., 30-s chair stand test (primary outcome), timed stair climbing, and 6-min walk test] and self-reported outcomes (i.e., physical function, pain, physical activity level, self-efficacy......This observer-blinded, randomized controlled trial compared the short- and long-term effects of 4 months of supervised strength training (ST) in a local fitness center, supervised Nordic Walking (NW) in a local park, and unsupervised home-based exercise (HBE, control) on functional performance...... activity and to both ST and HBE for improving (P exercise modality compared with ST and HBE....

  13. Effect of retro and forward walking on quadriceps muscle strength, pain, function, and mobility in patients with knee osteoarthritis: a protocol for a randomized controlled trial.

    Science.gov (United States)

    Alghadir, Ahmad; Anwer, Shahnawaz

    2016-04-12

    Walking, a closed kinetic chain (CKC) activity, is widely used in knee rehabilitation as it allows early weight bearing and movement. It has been suggested that retro-walking may provide additional benefits beyond those experienced by forward-walking. The present study will investigate the effect of retro- and forward-walking on quadriceps muscle strength, pain, function, balance and mobility in knee Osteoarthritis (OA) subjects. Sixty-nine participants with knee OA will be recruited from the outpatient department in this randomized controlled trial. The participants will be randomly assigned to one of three groups; retro walking, forward walking or control group. The training program will be 3 days/week for 6 weeks. In addition, all the participants will receive a standard physiotherapy training program. An independent assessor blinded to group assignment will measure quadriceps muscle strength, knee pain intensity, functional disability, and mobility at baseline and 6 weeks after training. The results of this study will enhance our understanding on the therapeutic effects of walking (retro- or forward-walking) in knee OA. The findings from this study will help determine whether retro- or forward-walking or both are effective in the rehabilitation of subjects with knee OA. Controlled Trials ISRCTN12850845, Registered 26 January 2015.

  14. Upper body strength and power are associated with shot speed in men's ice hockey

    Directory of Open Access Journals (Sweden)

    Juraj Bežák

    2017-06-01

    Full Text Available Background: Recent studies that addressed shot speed in ice hockey have focused on the relationship between shot speed and variables such as a player's skills or hockey stick construction and its properties. There has been a lack of evidence that considers the relationship between shot speed and player strength, particularly in players at the same skill level. Objective: The aim of this study was to identify the relationship between maximal puck velocity of two shot types (the wrist shot and the slap shot and players' upper body strength and power. Methods: Twenty male professional and semi-professional ice hockey players (mean age 23.3 ± 2.4 years participated in this study. The puck velocity was measured in five trials of the wrist shot and five trials of the slap shot performed by every subject. All of the shots were performed on ice in a stationary position 11.6 meters in front of an electronic device that measures the speed of the puck. The selected strength and power variables were: muscle power in concentric contraction in the countermovement bench press with 40 kg and 50 kg measured with the FiTRODyne Premium device; bench press one-repetition maximum; and grip strength measured by digital hand dynamometer. Results: The correlations between strength/power variables and the puck velocity in the wrist shot and the slap shot ranged between .29-.72 and .16-.62, respectively. Puck velocities produced by wrist shots showed significant correlations with bench press muscle power with 40 kg (p = .004 and 50 kg (p < .001; and one-repetition maximum in bench press (p = .004. The slap shot puck velocity was significantly associated with bench press muscle power with 40 kg (p = .014 and 50 kg (p = .004. Conclusions: This study provides evidence that there are significant associations between shot speed and upper body strength and power.

  15. Six-minute walk test and respiratory muscle strength in patients with uncontrolled severe asthma: a pilot study.

    Science.gov (United States)

    Pereira, Luiz Fernando Ferreira; Mancuzo, Eliane Viana; Rezende, Camila Farnese; Côrrea, Ricardo de Amorim

    2015-01-01

    To evaluate respiratory muscle strength and six-minute walk test (6MWT) variables in patients with uncontrolled severe asthma (UCSA). This was a cross-sectional study involving UCSA patients followed at a university hospital. The patients underwent 6MWT, spirometry, and measurements of respiratory muscle strength, as well as completing the Asthma Control Test (ACT). The Mann-Whitney test was used in order to analyze 6MWT variables, whereas the Kruskal-Wallis test was used to determine whether there was an association between the use of oral corticosteroids and respiratory muscle strength. We included 25 patients. Mean FEV1 was 58.8 ± 21.8% of predicted, and mean ACT score was 14.0 ± 3.9 points. No significant difference was found between the median six-minute walk distance recorded for the UCSA patients and that predicted for healthy Brazilians (512 m and 534 m, respectively; p = 0.14). During the 6MWT, there was no significant drop in SpO2. Mean MIP and MEP were normal (72.9 ± 15.2% and 67.6 ± 22.2%, respectively). Comparing the patients treated with at least four courses of oral corticosteroids per year and those treated with three or fewer, we found no significant differences in MIP (p = 0.15) or MEP (p = 0.45). Our findings suggest that UCSA patients are similar to normal subjects in terms of 6MWT variables and respiratory muscle strength. The use of oral corticosteroids has no apparent impact on respiratory muscle strength.

  16. Nordic Walking Can Be Incorporated in the Exercise Prescription to Increase Aerobic Capacity, Strength, and Quality of Life for Elderly: A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Bullo, Valentina; Gobbo, Stefano; Vendramin, Barbara; Duregon, Federica; Cugusi, Lucia; Di Blasio, Andrea; Bocalini, Danilo Sales; Zaccaria, Marco; Bergamin, Marco; Ermolao, Andrea

    2018-04-01

    The aim of this systematic review and meta-analysis was to summarize and analyze the effects of Nordic Walking on physical fitness, body composition, and quality of life in the elderly. Keyword "Nordic Walking" associated with "elderly" AND/OR "aging" AND/OR "old subjects" AND/OR "aged" AND/OR "older adults" were used in the online database MEDLINE, Embase, PubMed, Scopus, PsycINFO, and SPORTDiscus. Only studies written in English language and published in peer-reviewed journals were considered. A meta-analysis was performed and effect sizes calculated. Fifteen studies were identified; age of participants ranged from 60 to 92 years old. Comparing with a sedentary group, effect sizes showed that Nordic Walking was able to improve dynamic balance (0.30), functional balance (0.62), muscle strength of upper (0.66) and lower limbs (0.43), aerobic capacity (0.92), cardiovascular outcomes (0.23), body composition (0.30), and lipid profile (0.67). It seemed that Nordic Walking had a negative effect on static balance (-0.72). Comparing with a walking (alone) training, effect sizes showed that Nordic Walking improved the dynamic balance (0.30), flexibility of the lower body (0.47), and quality of life (0.53). Walking training was more effective in improving aerobic capacity (-0.21). Comparing Nordic Walking with resistance training, effect sizes showed that Nordic Walking improved dynamic balance (0.33), muscle strength of the lower body (0.39), aerobic capacity (0.75), flexibility of the upper body (0.41), and the quality of life (0.93). Nordic Walking can be considered as a safe and accessible form of aerobic exercise for the elderly population, able to improve cardiovascular outcomes, muscle strength, balance ability, and quality of life.

  17. Speed and duration of walking and other leisure time physical activity and the risk of heart failure: a prospective cohort study from the Copenhagen City Heart Study.

    Directory of Open Access Journals (Sweden)

    Hans Askelund Saevereid

    Full Text Available AIM: Physical activity (PA confers some protection against development of heart failure (HF but little is known of the role of intensity and duration of exercise. METHODS AND RESULTS: In a prospective cohort study of men and women free of previous MI, stroke or HF with one or more examinations in 1976-2003, we studied the association between updated self-assessed leisure-time PA, speed and duration of walking and subsequent hospitalization or death from HF. Light and moderate/high level of leisure-time PA and brisk walking were associated with reduced risk of HF in both genders whereas no consistent association with duration of walking was seen. In 18,209 subjects age 20-80 with 1580 cases of HF, using the lowest activity level as reference, the confounder-adjusted hazard ratios (HR for light and moderate/high leisure-time physical activity were 0.75 (0.66-0.86 and 0.80 (0.69-0.93, respectively. In 9,937 subjects with information on walking available and 542 cases of HF, moderate and high walking speed were associated with adjusted HRs of 0.53 (0.43-0.66 and 0.30 (0.21-0.44, respectively, and daily walking of ½-1 hrs, 1-2 and >2 hrs with HR of 0.80 (0.61-1.06, 0.82 (0.62-1.06, and 0.96 (0.73-1.27, respectively. Results were similar for both genders and remained robust after exclusion of HF related to coronary heart disease and after a series of sensitivity analyses. CONCLUSIONS: Speed rather than duration of walking was associated with reduced risk of HF. Walking is the most wide-spread PA and public health measures to curb the increase in HF may benefit from this information.

  18. EFFECT OF UPPER-LIMB AND THORACIC MUSCLE STRENGTH ON 6-MIN WALK DISTANCE IN COPD PATIENTS

    Directory of Open Access Journals (Sweden)

    D Varalakshmi

    2014-06-01

    Full Text Available Background: Chronic obstructive pulmonary disease (COPD is the only cause of death from chronic disease that will increase worldwide until 2020 and it represents a big burden for patients and society. Patients with COPD characteristically show poor exercise performance indicated by a marked reduction in both peak pulmonary 02 uptake and work rate at peak exercise. The sequelae of exercise intolerance include increased difficulty in performing daily tasks, etc. The objective of the study is to investigate the influence of thoracic and upper limb muscle function on 6-min walk distance (6MWD in patients with COPD. Method: Thirty eight COPD patients were included if they fulfilled the criteria for COPD according to the Global Initiative for Chronic Obstructive Lung Disease guidelines. Prospective, cross-sectional design with sample size of 38 patients. All patients performed 6MWD and 1RM exercises. Results: To study the correlation between variables, Pearson or Spearman coefficients of correlation were used with the level of statistical significance set at 5%.Results of this study suggested for the first time that thoracic muscle strength is a predictor of 6MWD in COPD patients. It also confirms the influence of respiratory muscle strength (Pimax, dyspnea, on the 6MWD of these patients. Conclusion: It is concluded that peripheral muscle strength, respiratory muscle strength, and the sensation of dyspnea all have an influence on the capacity of COPD patients to perform exercises.

  19. The influence of step frequency on the range of perceptually natural visual walking speeds during walking-in-place and treadmill locomotion

    DEFF Research Database (Denmark)

    Nilsson, Niels Christian; Serafin, Stefania; Nordahl, Rolf

    2014-01-01

    Walking-In-Place (WIP) techniques make relatively natural walking experiences within immersive virtual environments possible when the physical interaction space is limited in size. In order to facilitate such experiences it is necessary to establish a natural connection between steps in place and...

  20. Influence of the level of speed-strength preparedness on the agility of volleyball players 12–13 years old

    Directory of Open Access Journals (Sweden)

    Oleg Shevchenko

    2018-02-01

    Full Text Available Purpose: determine the impact level of indicators of speed-strength preparedness for the agility of young volleyball players 12–13 years. Material & Methods: analysis of scientific and methodological literature, pedagogical testing of speed-strength qualities and agility, pedagogical experiment, methods of mathematical statistics. The study involved 25 volleyball players aged 12–13 years, training in the basic training group of the second year of training of the sports club "Lokomotiv" in Kharkov. Young athletes were divided into an experimental – 13 people and a control –12 volleyball team. Results: after the introduction of the experimental methodology, a link was found between the level of speed-strength abilities and the agility of volleyball players. Conclusion: the positive influence of development of speed-strength qualities on indicators of agility of volleyball players that is necessary for selection of means and methods in training process of young athletes is proved.

  1. Means of Speed-Strength Abilities Development in Physical Training Classes with 10th Graders

    Directory of Open Access Journals (Sweden)

    С. А. Пашкевич

    2016-08-01

    Full Text Available The purpose of the research is to determine the means of development of speed-strength abilities manifesting in jump-offs in jumping exercises in classes with the 10th graders in order to improve the compliance with the standards of physical preparedness. Materials and methods. Analysis and collation of scientific and methodological literature, special preparedness testing, methods of mathematical statistics. The participants in the experiment were eight 10th-grade boys who turned fifteen or sixteen at the time of the experiment. Research results. During the experiment, we used the following tests: standing long jump, 30‑meter race from the standing start, standing triple jump. We suggested that the pupils perform special exercises: jumping on two legs and pulling up bent legs to the chest, repeated jumps on two legs over obstacles, jumping on two legs over the gymnastic bench while moving along the bench, jumping off a 60-70-cm height landing in half-squat, jumping off a 30-40-cm height onto two legs followed by a jump over obstacles (3-4 low barriers. Conclusions. When performing jumping exercises, it is necessary to create conditions for the reactive-ballistic type of muscle contractions. Experimental exercises were selected by the criteria of “the dynamic compliance principle” to correspond, fully or partly, to the nature of motor activity: motor structure, jump-off biodynamics, muscle tension regime, peculiarities of manifestation of speed-strength abilities.

  2. [Correlation between gait speed and muscular strength with balance for reducing falls among elderly].

    Science.gov (United States)

    García-Flores, Fabián Ituriel; Rivera-Cisneros, Antonio Eugenio; Sánchez-González, Jorge Manuel; Guardado-Mendoza, Rodolfo; Torres-Gutiérrez, Jorge Luis

    2016-01-01

    Evidence of the benefit on propioceptive neuromuscular facilitation for reducing falls in older people does not exist. The aim of this study is to evaluate the effects of propioceptive facilitation over falls and biomechanical variables, in comparison to standard treatment and control groups. Series cases comparative for the 24 participants were recruited and randomnly assigned to 3 groups. Group 1, propioceptive neuromuscular facilitation, group 2, standard treatment, and 3 control. Falls and biomechanic variables were measured before and after. Chi(2) was used for falls and multiple regression for biomechanical variables, Participants had similar falls in previous year. Women had higher falls in a relation 7:1 women-men. After intervention, there was no difference between 3 groups. A correlation exista between muscular strength and gait speed with one foot position time r(2) = 0.67, p = 0.02. Improving 1kilogram-force of muscular strength of pelvic limb and 0.1meter/second in gait speed, balance (unipodal position time) increases balance by 11.3%. After 3 months of intervention group 2 got 7.9kg-force and 0.26m/s of profit, while group 1 had 4.1kg-force and 0.15m/s and control group 2.4kg-force and 0.1m/s. Copyright © 2015 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

  3. Strength, power, speed, and agility of women basketball players according to playing position.

    Science.gov (United States)

    Delextrat, Anne; Cohen, Daniel

    2009-10-01

    The aim of the present study was to investigate the effect of playing position on strength, power, speed, and agility performances of women basketball players. Thirty subjects playing at national level participated in this study. They were divided into 3 groups according to playing position: guards (positions 1 and 2), forwards (positions 3 and 4), and centers (position 5). Each subject performed 8 tests presented in a random order: The 30-second Wingate Anaerobic test (WAnT), isokinetic testing of the knee extensors, 2 types of jump tests, a 20-m sprint, the agility T-test, a suicide run, and a basketball chest pass. Statistical differences between playing positions were assessed using a 1-way analysis of variance (ANOVA) and Scheffe post hoc analyses. Results showed that guards performed significantly better than centers for the relative peak and mean power achieved during the WAnT (+13% and +16.9%, respectively), relative peak torque of knee extensors (+19.5%), single-leg jump (+21.8), suicide run (+7.5%), and agility T-test (+6.4%, p training must be undertaken according to playing position. The ability to perform the suicide run, the single-leg jump, and the different movements involved in the agility T-test must be developed in guards. In contrast, speed over short distances and strength development of lower body and upper body should be performed by all playing positions.

  4. Non-random walk diffusion enhances the sink strength of semicoherent interfaces

    Science.gov (United States)

    Vattré, A.; Jourdan, T.; Ding, H.; Marinica, M.-C.; Demkowicz, M. J.

    2016-01-01

    Clean, safe and economical nuclear energy requires new materials capable of withstanding severe radiation damage. One strategy of imparting radiation resistance to solids is to incorporate into them a high density of solid-phase interfaces capable of absorbing and annihilating radiation-induced defects. Here we show that elastic interactions between point defects and semicoherent interfaces lead to a marked enhancement in interface sink strength. Our conclusions stem from simulations that integrate first principles, object kinetic Monte Carlo and anisotropic elasticity calculations. Surprisingly, the enhancement in sink strength is not due primarily to increased thermodynamic driving forces, but rather to reduced defect migration barriers, which induce a preferential drift of defects towards interfaces. The sink strength enhancement is highly sensitive to the detailed character of interfacial stresses, suggesting that `super-sink' interfaces may be designed by optimizing interface stress fields. Such interfaces may be used to create materials with unprecedented resistance to radiation-induced damage.

  5. Nonparetic Knee Extensor Strength Is the Determinant of Exercise Capacity of Community-Dwelling Stroke Survivors

    OpenAIRE

    Wang, Wei-Te; Huang, Ling-Tzu; Chou, Ya-Hui; Wei, Ta-Sen; Lin, Chung-Che

    2014-01-01

    Objective. To investigate the relationship among walking speed, exercise capacity, and leg strength in community dwelling stroke subjects and to evaluate which one was the leading determinant factor of them. Design. This is a descriptive, cross-sectional study. Thirty-five chronic stroke patients who were able to walk independently in their community were enrolled. Walking speed was evaluated by using the 12-meter walking test. A maximal exercise test was used to determine the stroke subjects...

  6. Therapeutic effects of maximal strength training on walking efficiency in patients with schizophrenia – a pilot study

    Directory of Open Access Journals (Sweden)

    Heggelund Jørn

    2012-07-01

    Full Text Available Abstract Background Patients with schizophrenia frequently have disabling gait deficits. The net mechanical efficiency of walking (ϵnet is an accurate measure often used to evaluate walking performance. Patients with gait deficits have a reduced ϵnet with excessive energy expenditure during sub-maximal walking. Maximal strength training (MST improves ϵnet in healthy individuals and is associated with reduced risk of mortality. The aim of this study was to investigate whether MST improves ϵnet in patients with schizophrenia. Methods Patients (ICD-10 schizophrenia, schizotypal or delusional disorders (F20-F29 were included in a non-randomized trial. Patients were assigned to one of two groups: 1 MST consisting of 4x4 repetitions at 85-90% one repetition maximum (1RM performed in a leg press apparatus or 2 playing computer games (CG. Both groups carried out their activity three days per week for eight weeks. 1RM, ϵnet at 60 watt walking, peak oxygen uptake (VO2peak, the Positive and Negative Syndrome Scale (PANSS and the 36-items short form (SF-36 were measured pre and post intervention. Results The baseline ϵnet was 17.3 ± 1.2% and 19.4 ± 3.0% in the MST (n = 6 and CG groups (n = 7, respectively, which is categorized as mechanical inefficiency. The MST group improved 1RM by 79 kg (p = 0.006 and ϵnet by 3.4% (p = 0.046 more than the CG group. The MST group improved 1RM and ϵnet, by a mean of 83 kg (p = 0.028 and 3.4% (p = 0.028, respectively. VO2peak at baseline was 34.2 ± 10.2 and 38.3 ± 9.8 ml·kg-1·min-1 in the MST and CG groups, respectively, and did not change (p > 0.05. No change was observed in PANSS or SF-36 (p > 0.05. Conclusions MST improves 1RM and ϵnet in patients with schizophrenia. MST could be used as a therapeutic intervention for patients with schizophrenia to normalize their reduced ϵnet.

  7. Effectiveness of Traditional Strength vs. Power Training on Muscle Strength, Power and Speed with Youth: A Systematic Review and Meta-Analysis

    Science.gov (United States)

    Behm, David G.; Young, James D.; Whitten, Joseph H. D.; Reid, Jonathan C.; Quigley, Patrick J.; Low, Jonathan; Li, Yimeng; Lima, Camila D.; Hodgson, Daniel D.; Chaouachi, Anis; Prieske, Olaf; Granacher, Urs

    2017-01-01

    Numerous national associations and multiple reviews have documented the safety and efficacy of strength training for children and adolescents. The literature highlights the significant training-induced increases in strength associated with youth strength training. However, the effectiveness of youth strength training programs to improve power measures is not as clear. This discrepancy may be related to training and testing specificity. Most prior youth strength training programs emphasized lower intensity resistance with relatively slow movements. Since power activities typically involve higher intensity, explosive-like contractions with higher angular velocities (e.g., plyometrics), there is a conflict between the training medium and testing measures. This meta-analysis compared strength (e.g., training with resistance or body mass) and power training programs (e.g., plyometric training) on proxies of muscle strength, power, and speed. A systematic literature search using a Boolean Search Strategy was conducted in the electronic databases PubMed, SPORT Discus, Web of Science, and Google Scholar and revealed 652 hits. After perusal of title, abstract, and full text, 107 studies were eligible for inclusion in this systematic review and meta-analysis. The meta-analysis showed small to moderate magnitude changes for training specificity with jump measures. In other words, power training was more effective than strength training for improving youth jump height. For sprint measures, strength training was more effective than power training with youth. Furthermore, strength training exhibited consistently large magnitude changes to lower body strength measures, which contrasted with the generally trivial, small and moderate magnitude training improvements of power training upon lower body strength, sprint and jump measures, respectively. Maturity related inadequacies in eccentric strength and balance might influence the lack of training specificity with the unilateral

  8. Effectiveness of Traditional Strength vs. Power Training on Muscle Strength, Power and Speed with Youth: A Systematic Review and Meta-Analysis

    Directory of Open Access Journals (Sweden)

    David G. Behm

    2017-06-01

    Full Text Available Numerous national associations and multiple reviews have documented the safety and efficacy of strength training for children and adolescents. The literature highlights the significant training-induced increases in strength associated with youth strength training. However, the effectiveness of youth strength training programs to improve power measures is not as clear. This discrepancy may be related to training and testing specificity. Most prior youth strength training programs emphasized lower intensity resistance with relatively slow movements. Since power activities typically involve higher intensity, explosive-like contractions with higher angular velocities (e.g., plyometrics, there is a conflict between the training medium and testing measures. This meta-analysis compared strength (e.g., training with resistance or body mass and power training programs (e.g., plyometric training on proxies of muscle strength, power, and speed. A systematic literature search using a Boolean Search Strategy was conducted in the electronic databases PubMed, SPORT Discus, Web of Science, and Google Scholar and revealed 652 hits. After perusal of title, abstract, and full text, 107 studies were eligible for inclusion in this systematic review and meta-analysis. The meta-analysis showed small to moderate magnitude changes for training specificity with jump measures. In other words, power training was more effective than strength training for improving youth jump height. For sprint measures, strength training was more effective than power training with youth. Furthermore, strength training exhibited consistently large magnitude changes to lower body strength measures, which contrasted with the generally trivial, small and moderate magnitude training improvements of power training upon lower body strength, sprint and jump measures, respectively. Maturity related inadequacies in eccentric strength and balance might influence the lack of training specificity with

  9. Rehabilitation that incorporates virtual reality is more effective than standard rehabilitation for improving walking speed, balance and mobility after stroke: a systematic review

    Directory of Open Access Journals (Sweden)

    Davide Corbetta

    2015-07-01

    Full Text Available Question: In people after stroke, does virtual reality based rehabilitation (VRBR improve walking speed, balance and mobility more than the same duration of standard rehabilitation? In people after stroke, does adding extra VRBR to standard rehabilitation improve the effects on gait, balance and mobility? Design: Systematic review with meta-analysis of randomised trials. Participants: Adults with a clinical diagnosis of stroke. Intervention: Eligible trials had to include one these comparisons: VRBR replacing some or all of standard rehabilitation or VRBR used as extra rehabilitation time added to a standard rehabilitation regimen. Outcome measures: Walking speed, balance, mobility and adverse events. Results: In total, 15 trials involving 341 participants were included. When VRBR replaced some or all of the standard rehabilitation, there were statistically significant benefits in walking speed (MD 0.15 m/s, 95% CI 0.10 to 0.19, balance (MD 2.1 points on the Berg Balance Scale, 95% CI 1.8 to 2.5 and mobility (MD 2.3 seconds on the Timed Up and Go test, 95% CI 1.2 to 3.4. When VRBR was added to standard rehabilitation, mobility showed a significant benefit (0.7 seconds on the Timed Up and Go test, 95% CI 0.4 to 1.1, but insufficient evidence was found to comment about walking speed (one trial and balance (high heterogeneity. Conclusion: Substituting some or all of a standard rehabilitation regimen with VRBR elicits greater benefits in walking speed, balance and mobility in people with stroke. Although the benefits are small, the extra cost of applying virtual reality to standard rehabilitation is also small, especially when spread over many patients in a clinic. Adding extra VRBR time to standard rehabilitation also has some benefits; further research is needed to determine if these benefits are clinically worthwhile. [Corbetta D, Imeri F, Gatti R (2015 Rehabilitation that incorporates virtual reality is more effective than standard

  10. Virtual Reality-Based Wii Fit Training in Improving Muscle Strength, Sensory Integration Ability, and Walking Abilities in Patients with Parkinson's Disease: A Randomized Control Trial

    Directory of Open Access Journals (Sweden)

    Ying-Yi Liao

    2015-12-01

    Conclusion: VRWii training is as beneficial as TE in improving walking abilities, sensory integration ability, and muscle strength in patients with PD, and such improvements persisted for at least for 1 month. VRWii training is thus suggested to be implemented in patients with PD.

  11. Hip abductors and thigh muscles strength ratios and their relation to electromyography amplitude during split squat and walking lunge exercises

    Directory of Open Access Journals (Sweden)

    Petr Stastny

    2015-06-01

    Full Text Available Background: The hip abductors (HAB, quadriceps (Q and hamstrings (H reciprocal strength ratios are predictors of electromyography (EMG amplitude during load carrying walking at moderate intensity. Therefore, these strength ratios might predict also the EMG during the exercises as walking lunge (WL or split squat (SSq at submaximal intensity. Objective: To determine whether the EMG amplitude of vastus mediali (VM, vastus laterali (VL, biceps femoris (BF and gluteus medius (Gmed is associated with muscle strength ratio during SSqs and WLs. To determine whether the EMG amplitude differs between individuals with HAB/H ratio above and below one and between individuals with H/Q or HAB/Q ratio above and below 0.5 during SSqs and WLs. Methods: 17 resistance-trained men (age 29.6 ± 4.6 years with at least 3 years of strength training performed in cross-sectional design 5 s maximal voluntary isometric contractions (MVIC on an isokinetic dynamometer for knee extension, knee flexion, and hip abduction. The MVIC was used to normalize the EMG signal and estimate the individual strength ratios. Than participants performed WL and SSq for a 5 repetition maximum, to find out muscle activity at submaximal intensity of exercise. Results: The H/Q ratio was associated by Kendall's tau (τ with VM (τ = .33 and BF (τ = -.71 amplitude, HAB/Q ratio was associated with BF (τ = -.43 and Gmed (τ = .38 amplitude, as well as HAB/H was associated with VM (τ = -.41 and Gmed (τ = .74 amplitude. ANOVA results showed significant differences between SSq and WL (F(4, 79 = 10, p < .001, ηp2 = .34 in Gmed amplitude, where WL resulted in higher Gmed amplitude compared to SSq. Other significant differences were found between H/Q groups (F(4, 29 = 3, p = .04, ηp2 = .28 in VM and Gmed amplitude, where group with H/Q > 0.5 showed higher VMO amplitude and lower Gmed amplitude. Furthermore, significant difference was found

  12. Later Age at Onset of Independent Walking Is Associated With Lower Bone Strength at Fracture-Prone Sites in Older Men.

    Science.gov (United States)

    Ireland, Alex; Muthuri, Stella; Rittweger, Joern; Adams, Judith E; Ward, Kate A; Kuh, Diana; Cooper, Rachel

    2017-06-01

    Later age at onset of independent walking is associated with lower leg bone strength in childhood and adolescence. However, it is unknown whether these associations persist into older age or whether they are evident at axial (central) or upper limb sites. Therefore, we examined walking age obtained at age 2 years and bone outcomes obtained by dual-energy X-ray absorptiometry (DXA) and peripheral quantitative computed tomography (pQCT) scans at ages 60 to 64 years in a nationally representative cohort study of British people, the MRC National Survey of Health and Development. It was hypothesized that later walking age would be associated with lower bone strength at all sites. Later independent walking age was associated with lower height-adjusted hip (standardized regression coefficients with 95% confidence interval [CI] -0.179 [-0.251 to -0.107]), spine (-0.157 [-0.232 to -0.082]), and distal radius (-0.159 [-0.245 to -0.073]) bone mineral content (BMC, indicating bone compressive strength) in men (all p lower lean mass and adolescent sporting ability in later walkers. These associations were also evident for a number of hip geometric parameters (including cross-sectional moment of inertia [CSMI], indicating bone bending/torsional strength) assessed by hip structural analysis (HSA) from DXA scans. Similar height-adjusted associations were also observed in women for several hip, spine, and upper limb outcomes, although adjustment for fat or lean mass led to complete attenuation for most outcomes, with the exception of femoral shaft CSMI and spine bone area (BA). In conclusion, later independent walking age appears to have a lifelong association with bone strength across multiple skeletal sites in men. These effects may result from direct effects of early life loading on bone growth and mediation by adult body composition. Results suggest that late walking age may represent a novel risk factor for subsequent low bone strength. Existing interventions effective in

  13. Speed

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Speed. The rate of information transferred per second is the speed of the information. Measured in bits per second. Need for speed on the net: You-Tube phenomenon; IPTV; 3D Video telephony. Online gaming; HDTV.

  14. Too much or too little step width variability is associated with a fall history in older persons who walk at or near normal gait speed

    Directory of Open Access Journals (Sweden)

    Newman Anne B

    2005-07-01

    Full Text Available Abstract Background Decreased gait speed and increased stride time, stride length, double support time, and stance time variability have consistently been associated with falling whereas step width variability has not been strongly related to falls. The purpose was to examine the linear and nonlinear associations between gait variability and fall history in older persons and to examine the influence of gait speed. Methods Gait characteristics and fall history were obtained in 503 older adults (mean age = 79; 61% female participating in the Cardiovascular Health Study who could ambulate independently. Gait characteristics were recorded from two trials on a 4 meter computerized walkway at the subject's self-selected walking speed. Gait variability was calculated as the coefficient of variation. The presence of a fall in the past 12 months was determined by interview. The nonlinear association between gait variability and fall history was examined using a simple three level classification derived from the distribution of the data and from literature based cut-points. Multivariate logistic regression was used to examine the association between step width variability (extreme or moderate and fall history stratifying by gait speed (1.0 m/s and controlling for age and gender. Results Step length, stance time, and step time variability did not differ with respect to fall history (p > .33. Individuals with extreme step width variability (either low or high step width variability were more likely to report a fall in the past year than individuals with moderate step width variability. In individuals who walked ≥ 1.0 m/s (n = 281, after controlling for age, gender, and gait speed, compared to individuals with moderate step width variability individuals with either low or high step width variability were more likely to have fallen in the past year (OR and 95% CI 4.38 [1.79–10.72]. The association between step width variability and fall history was not

  15. Multicomponent Exercise Improves Hemodynamic Parameters and Mobility, but Not Maximal Walking Speed, Transfer Capacity, and Executive Function of Older Type II Diabetic Patients

    Directory of Open Access Journals (Sweden)

    Hélio José Coelho Junior

    2018-01-01

    Full Text Available The present study aimed to investigate the effects of a 6-month multicomponent exercise program (MCEP on functional, cognitive, and hemodynamic parameters of older Type 2 diabetes mellitus (T2DM patients. Moreover, additional analyses were performed to evaluate if T2DM patients present impaired adaptability in response to physical exercise when compared to nondiabetic volunteers. A total of 72 T2DM patients and 72 age-matched healthy volunteers (CG were recruited and submitted to functional, cognitive, and hemodynamic evaluations before and after six months of a MCEP. The program of exercise was performed twice a week at moderate intensity. Results indicate T2DM and nondiabetic patients present an increase in mobility (i.e., usual walking speed after the MCEP. However, improvements in maximal walking speed, transfer capacity, and executive function were only observed in the CG. On the other hand, only T2DM group reveals a marked decline in blood pressure. In conclusion, data of the current study indicate that a 6-month MCEP improves mobility and reduce blood pressure in T2DM patients. However, maximal walking speed, transfer capacity, and executive function were only improved in CG, indicating that T2DM may present impaired adaptability in response to physical stimulus.

  16. Influence of Nordic Walking Training on Muscle Strength and the Electromyographic Activity of the Lower Body in Women With Low Bone Mass

    Directory of Open Access Journals (Sweden)

    Ossowski Zbigniew

    2016-06-01

    Full Text Available Introduction. Osteoporosis and osteopenia are related to changes in the quantity and quality of skeletal muscle and contribute to a decreased level of muscle strength. The purpose of this study was to evaluate the impact of Nordic walking training on muscle strength and the electromyographic (EMG activity of the lower body in women with low bone mass. Material and methods. The participants of the study were 27 women with low bone mass. The sample was randomly divided into two groups: a control group and an experimental group. Women from the experimental group participated in 12 weeks of regular Nordic walking training. Functional strength was assessed with a 30-second chair stand test. The EMG activities of the gluteus maximus (GMax, rectus femoris (RF, biceps femoris (BF, soleus (SOL, and lumbar (LB muscles were measured using a surface electromyogram. Results. Nordic walking training induced a significant increase in the functional strength (p = 0.006 of the lower body and activity of GMax (p = 0.013 and a decrease in body mass (p = 0.006 in women with reduced bone mass. There was no statistically significant increase in the EMG activities of the RF, BF, SOL, or LB muscles. The study did not indicate any significant changes in functional muscle strength, the EMG activity of the lower body, or anthropometry in women from the control group. Conclusions. Nordic walking training induces positive changes in lower body strength and the electromyographic activity of the gluteus maximus as well as a decrease in body mass in women with low bone mass.

  17. Relationships between field-based measures of strength and power and golf club head speed.

    Science.gov (United States)

    Read, Paul J; Lloyd, Rhodri S; De Ste Croix, Mark; Oliver, Jon L

    2013-10-01

    Increased golf club head speed (CHS) has been shown to result in greater driving distances and is also correlated with golf handicap. The purpose of this study was to investigate the relationships between field-based measures of strength and power and golf CHS with a secondary aim to determine the reliability of the selected tests. A correlation design was used to assess the following variables: anthropometrics, squat jump (SJ) height and squat jump peak power (SJPP), unilateral countermovement jump (CMJ) heights (right leg countermovement jump and left leg countermovement jump [LLCMJ]), bilateral CMJ heights, countermovement jump peak power (CMJPP), and medicine ball seated throw (MBST) and medicine ball rotational throw (MBRT). Fouty-eight male subjects participated in the study (age: 20.1 ± 3.2 years, height: 1.76 ± 0.07 m, mass: 72.8 ± 7.8 kg, handicap: 5.8 ± 2.2). Moderate significant correlations were reported between CHS and MBRT (r = 0.67; p golf athletes using the proposed battery of field tests. Additionally, movements that are more concentrically dominant in nature may display stronger relationships with CHS due to MBST and SJ displaying the highest explained variance after a stepwise linear regression.

  18. A Comparison of Isometric Midthigh-Pull Strength, Vertical Jump, Sprint Speed, and Change-of-Direction Speed in Academy Netball Players.

    Science.gov (United States)

    Thomas, Christopher; Comfort, Paul; Jones, Paul A; Dos'Santos, Thomas

    2017-08-01

    To investigate the relationships between maximal isometric strength, vertical jump (VJ), sprint speed, and change-of-direction speed (CoDS) in academy netball players and determine whether players who have high performance in isometric strength testing would demonstrate superior performance in VJ, sprint speed, and CoDS measures. Twenty-six young female netball players (age 16.1 ± 1.2 y, height 173.9 ± 5.7 cm, body mass 66.0 ± 7.2 kg) from a regional netball academy performed isometric midthigh pull (IMTP), squat jumps (SJs), countermovement jumps (CMJs), 10-m sprints, and CoDS (505). IMTP measures displayed moderate to strong correlations with sprint and CoDS performance (r = -.41 to -.66). The VJs, which included SJs and CMJs, demonstrated strong correlations with 10-m sprint times (r = -.60 to -.65; P strength to enhance VJ, sprint, and CoDS performance in youth netball players, with stronger athletes demonstrating superior VJ, sprint, and CoDS performances.

  19. Effects of material properties and speed of compression on microbial survival and tensile strength in diclofenac tablet formulations.

    Science.gov (United States)

    Ayorinde, J O; Itiola, O A; Odeniyi, M A

    2013-03-01

    A work has been done to study the effects of material properties and compression speed on microbial survival and tensile strength in diclofenac tablet formulations. Tablets were produced from three formulations containing diclofenac and different excipients (DC, DL and DDCP). Two types of machines (Hydraulic hand press and single punch press), which compress the tablets at different speeds, were used. The compression properties of the tablets were analyzed using Heckel and Kawakita equations. A 3-dimensional plot was produced to determine the relationship between the tensile strength, compression speed and percentage survival of Bacillus subtilis in the diclofenac tablets. The mode of consolidation of diclofenac was found to depends on the excipient used in the formulation. DC deformed mainly by plastic flow with the lowest Py and Pk values. DL deformed plastically at the initial stage, followed by fragmentation at the later stage of compression, whereas DDCP deformed mainly by fragmentation with the highest Py and Pk values. The ranking of the percentage survival of B. subtilis in the formulations was DDCP > DL > DC, whereas the ranking of the tensile strength of the tablets was DDCP > DL > DC. Tablets produced on a hydraulic hand press with a lower compression speed had a lower percentage survival of microbial contaminants than those produced on a single punch press, which compressed the tablets at a much higher speed. The mode of consolidation of the materials and the speed at which tablet compression is carried out have effects on both the tensile strength of the tablets and the extent of destruction of microbial contaminants in diclofenac tablet formulations.

  20. Complementarity and quantum walks

    International Nuclear Information System (INIS)

    Kendon, Viv; Sanders, Barry C.

    2005-01-01

    We show that quantum walks interpolate between a coherent 'wave walk' and a random walk depending on how strongly the walker's coin state is measured; i.e., the quantum walk exhibits the quintessentially quantum property of complementarity, which is manifested as a tradeoff between knowledge of which path the walker takes vs the sharpness of the interference pattern. A physical implementation of a quantum walk (the quantum quincunx) should thus have an identifiable walker and the capacity to demonstrate the interpolation between wave walk and random walk depending on the strength of measurement

  1. Respiratory muscle strength and pulmonary function in children with rhinitis and asthma after a six-minute walk test.

    Science.gov (United States)

    Soares, Ana Alice de Almeida; Barros, Camila Moraes; Santos, Cássia Giulliane Costa; Dos Santos, Maria Renata Aragão; Silva, José Rodrigo Santos; Silva Junior, Walderi Monteiro da; Simões, Silvia de Magalhães

    2018-03-01

    Rhinitis and asthma decrease quality of life. Few studies have assessed the performance of children with asthma or rhinitis under submaximal exercise. We evaluated maximal respiratory pressures, spirometric parameters, and ability to sustain submaximal exercise in these children before and after the 6-minute walk test (6MWT), compared to healthy children. This cross-sectional, analytical study included 89 children aged 6-12 years in outpatient follow-up: 27 healthy (H), 31 with rhinitis (R), and 31 with mild asthma under control (A). Pulmonary function parameters and maximal respiratory pressures were measured before and 5, 10, and 30 minutes after the 6MWT. Wilcoxon test was used to compare numerical numerical variables between two groups and analysis of variance or Kruskal-Wallis test for comparison among three groups. Total distance traveled in the 6MWT was similar among the three groups. Compared to pre-test values, VEF1 (Forced Expiratory Volume in 1 second), VEF0.75 (Forced Expiratory Volume in 0.75 second), and FEF25-75 (Forced Expiratory Flow 25-75% of the Forced Vital Capacity - CVF - curve) decreased significantly after the 6MWT in group A, and VEF0.75, FEF25-75, and VEF1/CVF decreased significantly in group R. Groups A and R had lower Maximum Inspiratory Pressure values than group H before and after the 6MWT at all time points assessed. The findings suggest that children with rhinitis and mild asthma present with alterations in respiratory muscle strength and pulmonary function not associated with clinical complaints, reinforcing the concept of the united airways.

  2. Anticipatory changes in control of swing foot and lower limb joints when walking onto a moving surface traveling at constant speed.

    Science.gov (United States)

    Hsu, Wei-Chun; Wang, Ting-Ming; Lu, Hsuan-Lun; Lu, Tung-Wu

    2015-01-01

    Adapting to a predictable moving surface such as an escalator is a crucial part of daily locomotor tasks in modern cities. However, the associated biomechanics have remained unexplored. In a gait laboratory, fifteen young adults walked from the ground onto a moving or a static surface while their kinematic and kinetic data were obtained for calculating foot and pelvis motions, as well as the angles and moments of the lower limb joints. Between-surface-condition comparisons were performed using a paired t-test (α = 0.05). The results showed that anticipatory locomotor adjustments occurred at least a stride before successfully walking onto the moving surface, including increasing step length and speed in the trailing step (p moving surface (p > 0.05), mainly through reduced extension of the trailing hip but increased pelvic anterior tilt and leading swing ankle plantarflexion (p moving surfaces such as escalators. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Nonparetic Knee Extensor Strength Is the Determinant of Exercise Capacity of Community-Dwelling Stroke Survivors

    Directory of Open Access Journals (Sweden)

    Wei-Te Wang

    2014-01-01

    Full Text Available Objective. To investigate the relationship among walking speed, exercise capacity, and leg strength in community dwelling stroke subjects and to evaluate which one was the leading determinant factor of them. Design. This is a descriptive, cross-sectional study. Thirty-five chronic stroke patients who were able to walk independently in their community were enrolled. Walking speed was evaluated by using the 12-meter walking test. A maximal exercise test was used to determine the stroke subjects’ exercise capacity. Knee extensor strength, measured as isokinetic torque, was assessed by isokinetic dynamometer. Results. The main walking speed of our subjects was 0.52 m/s. Peak oxygen uptake (VO2 peak was 1.21±0.43 L/min. Knee extensor strength, no matter whether paretic or nonparetic side, was significantly correlated to 12-meter walking speed and exercise capacity. Linear regression also showed the strength of the affected knee extensor was the determinant of walking speed and that of the nonparetic knee extensor was the determinant of exercise capacity in community dwelling stroke subjects. Conclusions. Walking speed and peak oxygen uptake were markedly decreased after stroke. Knee extensor strength of nonparetic leg was the most important determinant of exercise capacity of the community-dwelling stroke subjects. Knee extensor strengthening should be emphasized to help stroke patient to achieve optimal community living.

  4. Nonparetic knee extensor strength is the determinant of exercise capacity of community-dwelling stroke survivors.

    Science.gov (United States)

    Wang, Wei-Te; Huang, Ling-Tzu; Chou, Ya-Hui; Wei, Ta-Sen; Lin, Chung-Che

    2014-01-01

    To investigate the relationship among walking speed, exercise capacity, and leg strength in community dwelling stroke subjects and to evaluate which one was the leading determinant factor of them. This is a descriptive, cross-sectional study. Thirty-five chronic stroke patients who were able to walk independently in their community were enrolled. Walking speed was evaluated by using the 12-meter walking test. A maximal exercise test was used to determine the stroke subjects' exercise capacity. Knee extensor strength, measured as isokinetic torque, was assessed by isokinetic dynamometer. The main walking speed of our subjects was 0.52 m/s. Peak oxygen uptake (VO₂ peak) was 1.21 ± 0.43 L/min. Knee extensor strength, no matter whether paretic or nonparetic side, was significantly correlated to 12-meter walking speed and exercise capacity. Linear regression also showed the strength of the affected knee extensor was the determinant of walking speed and that of the nonparetic knee extensor was the determinant of exercise capacity in community dwelling stroke subjects. Walking speed and peak oxygen uptake were markedly decreased after stroke. Knee extensor strength of nonparetic leg was the most important determinant of exercise capacity of the community-dwelling stroke subjects. Knee extensor strengthening should be emphasized to help stroke patient to achieve optimal community living.

  5. Effect of the Power Balance® hologram on balance, flexibility, strength and speed-coordination among university students

    Directory of Open Access Journals (Sweden)

    Rafael Merino Marban, Daniel Mayorga Vega, Emilio Fernández Rodríguez, Francisco José Santana Pérez, Oscar Romero Ramos

    2011-01-01

    Full Text Available Based on the body’s energy field, the inventors of Power Balance® have created a hologram that theoretically runs through frequencies that are in our natural environment. Its creators say that people may experience improve balance, strength, flexibility, endurance, concentration, coordination and recovery time, among others. The purpose of this research is to evaluate the effect of Power Balance® hologram on balance, flexibility, strength and speed-coordination in university students. A sample of 105 young volunteers’ physical education students (age 20.91 ± 3.36 years, mass 69.69 ± 11.35 kg, height 171.70 ± 8.07 cm was used. A between-group experimental design with double-blind control group was used to evaluate the possible effects of the Power Balance ® on the dynamic balance, flexibility, abdominal strength, endurance and speed-coordination measured with the Dynamic Balance Test, Sit and Reach, Sit-ups in 30 seconds and Race 10 x 5 m, respectively. A t of Student for independent and dependent samples was used to assess the potential effects between-group and intra-group, respectively. Power Balance®’s hologram produces no significant effects on the balance, flexibility, strength and speed-coordination among university students

  6. Effect of speed endurance and strength training on performance, running economy and muscular adaptations in endurance-trained runners

    DEFF Research Database (Denmark)

    Vorup Petersen, Jacob; Tybirk, Jonas; Gunnarsson, Thomas Petursson

    2016-01-01

    PURPOSE: To investigate the effects of combined strength and speed endurance (SE) training along with a reduced training volume on performance, running economy and muscular adaptations in endurance-trained runners. METHODS: Sixteen male endurance runners (VO2-max: ~60 ml kg(-1) min(-1)) were rand...... and speed endurance training, along with a reduced training volume, can improve short-term exercise capacity and induce muscular adaptations related to anaerobic capacity in endurance-trained runners.......PURPOSE: To investigate the effects of combined strength and speed endurance (SE) training along with a reduced training volume on performance, running economy and muscular adaptations in endurance-trained runners. METHODS: Sixteen male endurance runners (VO2-max: ~60 ml kg(-1) min(-1)) were...... randomly assigned to either a combined strength and SE training (CSS; n = 9) or a control (CON; n = 7) group. For 8 weeks, CSS replaced their normal moderate-intensity training (~63 km week(-1)) with SE (2 × week(-1)) and strength training (2 × week(-1)) as well as aerobic high (1 × week(-1)) and moderate...

  7. Anthropometric, biomechanical, and isokinetic strength predictors of ball release speed in high-performance cricket fast bowlers.

    Science.gov (United States)

    Wormgoor, Shohn; Harden, Lois; Mckinon, Warrick

    2010-07-01

    Fast bowling is fundamental to all forms of cricket. The purpose of this study was to identify parameters that contribute to high ball release speeds in cricket fast bowlers. We assessed anthropometric dimensions, concentric and eccentric isokinetic strength of selected knee and shoulder muscle groups, and specific aspects of technique from a single delivery in 28 high-performance fast bowlers (age 22.0 +/- 3.0 years, ball release speed 34.0 +/- 1.3 m s(-1)). Six 50-Hz cameras and the Ariel Performance Analysis System software were used to analyse the fast and accurate deliveries. Using Pearson's correlation, parameters that showed significant associations with ball release speed were identified. The findings suggest that greater front leg knee extension at ball release (r=0.52), shoulder alignment in the transverse plane rotated further away from the batsman at front foot strike (r=0.47), greater ankle height during the delivery stride (r=0.44), and greater shoulder extension strength (r=0.39) contribute significantly to higher ball release speeds. Predictor variables failed to allow their incorporation into a multivariate model, which is known to exist in less accomplished bowlers, suggesting that factors that determine ball release speed found in other groups may not apply to high-performance fast bowlers.

  8. Comparison of the Mini-Balance Evaluations Systems Test with the Berg Balance Scale in relationship to walking speed and motor recovery post stroke.

    Science.gov (United States)

    Madhavan, Sangeetha; Bishnoi, Alka

    2017-12-01

    The Mini-BESTest is a recently developed balance assessment tool that incorporates challenging dynamic balance tasks. Few studies have compared the psychometric properties of the Mini-BESTest to the commonly used Berg Balance Scale (BBS). However, the utility of these scales in relationship to post stroke walking speeds has not been explored. The purpose of this study was to compare the sensitivity and specificity of the Mini-BESTest and BBS to evaluate walking speeds in individuals with stroke. A retrospective exploratory design. Forty-one individuals with chronic stroke were evaluated with the Mini-BESTest, BBS, and 10-meter self-selected walk test (10MWT). Based on their self-selected gait speeds (below or above 0.8 m/s), participants were classified as slow and fast walkers. Significant linear correlations were observed between the Mini-BESTest vs. BBS (r = 0.72, p ≤ 0.001), Mini-BESTest vs. 10MWT (r = 0.58, p ≤ 0.001), and BBS vs. 10MWT (r = 0.30, p = 0.05). Independent t-tests comparing the balance scores for the slow and fast walkers revealed significant group differences for the Mini-BESTest (p = 0.003), but not for the BBS (p = 0.09). The Mini-BESTest demonstrated higher sensitivity (93%) and specificity (64%) compared to the BBS (sensitivity 81%, specificity 56%) for discriminating participants into slow and fast walkers. The Mini-BESTest has a greater discriminative ability than the BBS to categorize individuals with stroke into slow and fast walkers.

  9. Characteristics of the gait adaptation process due to split-belt treadmill walking under a wide range of right-left speed ratios in humans.

    Science.gov (United States)

    Yokoyama, Hikaru; Sato, Koji; Ogawa, Tetsuya; Yamamoto, Shin-Ichiro; Nakazawa, Kimitaka; Kawashima, Noritaka

    2018-01-01

    The adaptability of human bipedal locomotion has been studied using split-belt treadmill walking. Most of previous studies utilized experimental protocol under remarkably different split ratios (e.g. 1:2, 1:3, or 1:4). While, there is limited research with regard to adaptive process under the small speed ratios. It is important to know the nature of adaptive process under ratio smaller than 1:2, because systematic evaluation of the gait adaptation under small to moderate split ratios would enable us to examine relative contribution of two forms of adaptation (reactive feedback and predictive feedforward control) on gait adaptation. We therefore examined a gait behavior due to on split-belt treadmill adaptation under five belt speed difference conditions (from 1:1.2 to 1:2). Gait parameters related to reactive control (stance time) showed quick adjustments immediately after imposing the split-belt walking in all five speed ratios. Meanwhile, parameters related to predictive control (step length and anterior force) showed a clear pattern of adaptation and subsequent aftereffects except for the 1:1.2 adaptation. Additionally, the 1:1.2 ratio was distinguished from other ratios by cluster analysis based on the relationship between the size of adaptation and the aftereffect. Our findings indicate that the reactive feedback control was involved in all the speed ratios tested and that the extent of reaction was proportionally dependent on the speed ratio of the split-belt. On the contrary, predictive feedforward control was necessary when the ratio of the split-belt was greater. These results enable us to consider how a given split-belt training condition would affect the relative contribution of the two strategies on gait adaptation, which must be considered when developing rehabilitation interventions for stroke patients.

  10. Walking speed, rather than Expanded Disability Status Scale, relates to long-term patient-reported impact in progressive MS

    NARCIS (Netherlands)

    Bosma, L.V.A.E.; Kragt, J.J.; Polman, C.H.; Uitdehaag, B.M.J.

    2013-01-01

    Objective: To study the relationships between 1-2 year changes in well-known physician-rated measurements (Expanded Disability Status Scale (EDSS), Timed 25-Foot Walk (T25FW), 9-Hole Peg Test (9HPT)) and the long-term (= 5 years) outcome in patient-reported outcome (PRO) measures (Multiple Sclerosis

  11. Self-paced versus fixed speed walking and the effect of virtual reality in children with cerebral palsy

    NARCIS (Netherlands)

    Sloot, L.H.; Harlaar, J.; van der Krogt, M.M.

    2015-01-01

    While feedback-controlled treadmills with a virtual reality could potentially offer advantages for clinical gait analysis and training, the effect of self-paced walking and the virtual environment on the gait pattern of children and different patient groups remains unknown. This study examined the

  12. Examining the influence of injection speed and mould temperature on the tensile strength of polypropylene and ABS

    DEFF Research Database (Denmark)

    Aarøe, Esben Raahede; Blaimschein, Karl Stephan; Deker, Lasse

    This report is the final task of course “41738 Experimental Plastics Technology” in the three weeks period of June 2009 at DTU, IPL. The aim of this project has been to investigate the ultimate tensile strength behaviour of two different polymers, with different structural composition, by varying...... the injection speed and the mold temperature independently while keeping all other process parameters fixed. In addition the scaling from production of large to small geometries has been investigated by doing two parallel productions and test setups of respectively injection moulded and micro injection moulded...... specimens. After production and tensile testing the specimens were examined with a microscope to underpin conclusions from the tensile test data. It was experienced that the injection speed in general increased the the tensile strength by orienting the polymeric-chains lengthwise in the specimens and thus...

  13. Features of high-speed and strength qualities development in young biathlonists aged 14–15 in the preparatory period

    Directory of Open Access Journals (Sweden)

    Artem Burla

    2015-04-01

    Full Text Available Purpose: to substantiate a methodology of high-speed and strength qualities development of young biathlonists aged 14–15 during the preparatory period. Material and Methods: young biathlonists aged 14–15 from control and experimental groups took part in the research. There were 12 athletes in each group. Pedagogical methods and methods of mathematical statistics were used in the work. Pedagogical methods of researches were used for level definition of high-speed and strength qualities development of young biathlonists. Results: reliable increase of motive qualities and polydynamometry results testing of young biathlonists from the experimental group due to implementation of the experimental methodology in the preparatory period is established. Conclusions: application of the developed complexes in the preparatory period in the experimental group of young biathlonists aged 14–15 allows to raise indices of motive qualities and polydynamometry testing statistically significantly.

  14. Effect of High-Speed Strength Training on Physical Performance in Young Soccer Players of Different Ages.

    Science.gov (United States)

    Rodríguez-Rosell, David; Franco-Márquez, Felipe; Mora-Custodio, Ricardo; González-Badillo, Juan José

    2017-09-01

    Rodríguez-Rosell, D, Franco-Márquez, F, Mora-Custodio, R, and González-Badillo, JJ. Effect of high-speed strength training on physical performance in young soccer players of different ages. J Strength Cond Res 31(9): 2498-2508, 2017-The aim of the present study was to compare the effectiveness of low-load, low-volume weight training combined with plyometrics on strength, sprint, and jump performance in soccer players of different ages. Eighty-six soccer players from the same academy were categorized into 3 groups by age (under 13 years, U13, n = 30; under 15, U15, n = 28; and under 17, U17, n = 28) and then randomly assigned into 2 subgroups: a strength training group (STG) and a control group (CG). The strength training program was performed twice a week for 6 weeks and consisted of full squats (load: 45-60% 1 repetition maximum; volume: 3 set of 8-4 repetitions), jumps, and straight line sprint exercises. After training intervention, the STGs showed significant improvements in maximal strength (7.5-54.5%; p soccer players in most variables, whereas U15 showed higher improvements in jump and strength parameters than U17 (ES: 0.25-0.90) soccer players. Thus, although our results indicates that a combined weight training and plyometrics program may be effective in eliciting gains in strength, jump, and sprint in soccer players of different ages, the training program used appears to be generally less effective as the age of the soccer players increased. Therefore, it appears that training characteristics (mainly volume, intensity, and type of exercise) should be modified in relation to maturity status and initial strength level.

  15. The Gluteus Medius Vs. Thigh Muscles Strength Ratio and Their Relation to Electromyography Amplitude During a Farmer’s Walk Exercise

    Directory of Open Access Journals (Sweden)

    Stastny Petr

    2015-03-01

    Full Text Available The strength ratio between hamstrings and quadriceps (H/Q is associated with knee injuries as well as hip abductor muscle (HAB weakness. Sixteen resistance trained men (age, 32.5 ± 4.2 years performed 5 s maximal isometric contractions at 75° of knee flexion/extension and 15° of hip abduction on a dynamometer. After this isometric test they performed a Farmer´s walk exercise to find out if the muscle strength ratio predicted the electromyography amplitude expressed as a percentage of maximum voluntary isometric contraction (%MVIC. The carried load represented a moderate intensity of 75% of the exercise six repetitions maximum (6RM. Electromyography data from the vastus medialis (VM, vastus lateralis (VL, biceps femoris (BF and gluteus medius (Gmed on each leg were collected during the procedure. The groups selected were participants with H/Q ≥ 0.5, HQ < 0.5, HAB/H ≥ 1, HAB/H < 1, HAB/Q ≥ 0.5 and HAB/Q < 0.5. One way ANOVA showed that Gmed activity was significantly greater in the group with HAB/H < 1 (42 ± 14 %MVIC as compared to HAB/H ≥ 1 (26 ± 10 %MVIC and HAB/Q < 0.5 (47 ± 19 %MVIC compared to HAB/Q ≥ 0.5 (26 ± 12 %MVIC. The individuals with HAB/H < 1 were found to have greater activation of their Gmed during the Farmer’s walk exercise. Individuals with HAB/Q < 0.5 had greater activation of the Gmed. Gmed strength ratios predict the muscle involvement when a moderate amount of the external load is used. The Farmer’s walk is recommended as an exercise which can strengthen the gluteus medius, especially for individuals with a HAB/H ratio < 1 and HAB/Q < 0.5.

  16. High-intensity resistance training in multiple sclerosis - An exploratory study of effects on immune markers in blood and cerebrospinal fluid, and on mood, fatigue, health-related quality of life, muscle strength, walking and cognition.

    Science.gov (United States)

    Kierkegaard, Marie; Lundberg, Ingrid E; Olsson, Tomas; Johansson, Sverker; Ygberg, Sofia; Opava, Christina; Holmqvist, Lotta Widén; Piehl, Fredrik

    2016-03-15

    High-intensity resistance training is unexplored in people with multiple sclerosis. To evaluate effects of high-intensity resistance training on immune markers and on measures of mood, fatigue, health-related quality of life, muscle strength, walking and cognition. Further, to describe participants' opinion and perceived changes of the training. Twenty patients with relapsing-remitting multiple sclerosis performed high-intensity resistance training at an intensity of 80% of one-repetition maximum, twice a week for 12 weeks. Blood and optional cerebrospinal fluid samples, and data on secondary outcome measures were collected before and after intervention. A study-specific questionnaire was used for capturing participants' opinion. Seventeen participants completed the study. Plasma cytokine levels of tumor necrosis factor were significantly decreased post-intervention (p=0.001). Exploratory cytokine analyses in cerebrospinal fluid (n=8) did not reveal major changes. Significant and clinically important improvements were found in fatigue (p=0.001) and health-related quality of life (p=0.004). Measures of mood (p=0.002), muscle strength (p ≤ 0.001), walking speed (p=0.013) and cognition (p=0.04) were also improved. A majority of participants evaluated the training as very good and perceived changes to the better. High-intensity resistance training in persons with relapsing remitting multiple sclerosis with low disability had positive effects on peripheral pro-inflammatory cytokine levels, led to clinically relevant improvements in measures of fatigue and health-related quality of life, and was well tolerated. These results provide a basis for a larger randomized trial. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Reliability and validity of a smartphone-based assessment of gait parameters across walking speed and smartphone locations: Body, bag, belt, hand, and pocket.

    Science.gov (United States)

    Silsupadol, Patima; Teja, Kunlanan; Lugade, Vipul

    2017-10-01

    The assessment of spatiotemporal gait parameters is a useful clinical indicator of health status. Unfortunately, most assessment tools require controlled laboratory environments which can be expensive and time consuming. As smartphones with embedded sensors are becoming ubiquitous, this technology can provide a cost-effective, easily deployable method for assessing gait. Therefore, the purpose of this study was to assess the reliability and validity of a smartphone-based accelerometer in quantifying spatiotemporal gait parameters when attached to the body or in a bag, belt, hand, and pocket. Thirty-four healthy adults were asked to walk at self-selected comfortable, slow, and fast speeds over a 10-m walkway while carrying a smartphone. Step length, step time, gait velocity, and cadence were computed from smartphone-based accelerometers and validated with GAITRite. Across all walking speeds, smartphone data had excellent reliability (ICC 2,1 ≥0.90) for the body and belt locations, with bag, hand, and pocket locations having good to excellent reliability (ICC 2,1 ≥0.69). Correlations between the smartphone-based and GAITRite-based systems were very high for the body (r=0.89, 0.98, 0.96, and 0.87 for step length, step time, gait velocity, and cadence, respectively). Similarly, Bland-Altman analysis demonstrated that the bias approached zero, particularly in the body, bag, and belt conditions under comfortable and fast speeds. Thus, smartphone-based assessments of gait are most valid when placed on the body, in a bag, or on a belt. The use of a smartphone to assess gait can provide relevant data to clinicians without encumbering the user and allow for data collection in the free-living environment. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. The 1-Minute Sit-to-Stand Test in Adults With Cystic Fibrosis: Correlations With Cardiopulmonary Exercise Test, 6-Minute Walk Test, and Quadriceps Strength.

    Science.gov (United States)

    Gruet, Mathieu; Peyré-Tartaruga, Leonardo Alexandre; Mely, Laurent; Vallier, Jean-Marc

    2016-12-01

    Exercise testing is part of the regular assessment of patients with cystic fibrosis (CF). We aimed to evaluate (1) the convergent validity of the 1-min sit-to-stand (STS) test in CF by investigating its relationships with peak oxygen uptake (peak V̇ O 2 ), quadriceps strength, and quality of life and (2) to compare these associations with those of the 6-min walk test (6MWT). Twenty-five adults with CF (FEV 1 = 59 ± 24%) performed the STS test, the 6MWT, quadriceps strength assessment, and cardiopulmonary exercise test (CPET). Physical activity level, quality of life, and self-esteem were assessed by questionnaires. STS repetitions, 6-min walk distance, quadriceps strength, and peak V̇ O 2 were, respectively, 71 ± 12, 90 ± 10, 93 ± 29, and 62 ± 16% of predicted. The STS test had moderate associations with peak V̇ O 2 (r = 0.56, P = .004), quadriceps strength (r = 0.52, P = .008), and some questionnaire items (eg, perceived physical strength, r = 0.67, P test was strongly associated with oxygen desaturation during CPET (r = 0.80, P test as compared with CPET (P test cannot be used as a replacement for CPET to accurately assess peak exercise capacity in CF. The STS test may have utility in detecting patients with CF who may exhibit a high level of oxygen desaturation during heavy exercise. Further studies should identify the factors contributing to STS performance to confirm the potential interest of STS repetitions × body weight outcome as a useful submaximal exercise parameter in CF. Copyright © 2016 by Daedalus Enterprises.

  19. Relationships between Lower Limb Muscle Strength and Locomotor Capacity in Children and Adolescents with Cerebral Palsy Who Walk Independently

    Science.gov (United States)

    Ferland, Chantale; Lepage, Celine; Moffet, Helene; Maltais, Desiree B.

    2012-01-01

    This study aimed to quantify relationships between lower limb muscle strength and locomotor capacity for children and adolescents with cerebral palsy (CP) to identify key muscle groups for strength training. Fifty 6- to 16-year-olds with CP (Gross Motor Function Classification System level I or II) participated. Isometric muscle strength of hip…

  20. Influence of different crosshead speeds on diametral tensile strength of a methacrylate based resin composite: An in-vitro study.

    Science.gov (United States)

    Sood, Anubhav; Ramarao, Sathyanarayanan; Carounanidy, Usha

    2015-01-01

    The aim was to evaluate the influence of different crosshead speeds on diametral tensile strength (DTS) of a resin composite material (Tetric N-Ceram). The DTS of Tetric N-Ceram was evaluated using four different crosshead speeds 0.5 mm/min (DTS 1), 1 mm/min (DTS 2), 5 mm/min (DTS 3), 10 mm/min (DTS 4). A total of 48 specimens were prepared and divided into four subgroups with 12 specimens in each group. Specimens were made using stainless steel split custom molds of dimensions 6 mm diameter and 3 mm height. The specimens were stored in distilled water at room temperature for 24 h. Universal testing machine was used and DTS values were calculated in MPa. Analysis of variance was used to compare the four groups. Higher mean DTS value was recorded in DTS 2 followed by DTS 4, DTS 1, and DTS 3, respectively. However, the difference in mean tensile strength between the groups was not statistically significant (P > 0.05). The crosshead speed variation between 0.5 and 10 mm/min does not seem to influence the DTS of a resin composite.

  1. Impact of the difference in the plantar flexor strength of the ankle joint in the affected side among hemiplegic patients on the plantar pressure and walking asymmetry.

    Science.gov (United States)

    You, Young Youl; Chung, Sin Ho; Lee, Hyung Jin

    2016-11-01

    [Purpose] This study was to examine the changes in the gait lines and plantar pressures in static and dynamic circumstances, according to the differences in the strengths of the plantar flexors in the ankle joints on the affected sides of hemiplegic patients, and to determine their impacts on walking symmetry. [Subjects and Methods] A total of thirty hospitalized stroke patients suffering from hemiplegia were selected in this study. The subjects had ankylosing patterns in the ankle joints of the affected sides. Fifteen of the patients had plantar flexor manual muscle testing scores between poor and fair, while fifteen of the patients had zero and trace. [Results] The contact pattern of the plantar surface with the ground is a reliable method for walking analysis, which is an important index for understanding the ankle mechanism and the relationship between the plantar surface and the ground. [Conclusion] The functional improvement of patients with stroke could be supported through a verification of the analysis methods of the therapy strategy and walking pattern.

  2. Effects of Muscle Strength and Balance Control on Sit-to-Walk and Turn Durations in the Timed Up and Go Test.

    Science.gov (United States)

    Chen, Tzurei; Chou, Li-Shan

    2017-12-01

    To examine the association of muscle strength and balance control with the amount of time taken to perform sit-to-walk (STW) or turning components of the Timed Up and Go (TUG) test in older adults. Correlations; multiple regression models. General community. Older adults (N=60) age >70 years recruited from the community. Not applicable. Muscle strength, balance control, and TUG test performance time. Muscle strength was quantified by peak joint moments during the isometric maximal voluntary contraction test for bilateral hip abductors, knee extensors, and ankle plantar flexors. Balance control was assessed with the Berg Balance Scale, Fullerton Advanced Balance Scale, and center of mass and ankle inclination angle derived during the TUG test performance. We found that balance control measures were significantly associated with both STW and turning durations even after controlling for muscle strength and other confounders (STW duration: Pbalance control is an important factor that contributes to longer STW and turning durations on the TUG test. Furthermore, strength has a higher association with STW than turning duration. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  3. Predictive neuromechanical simulations indicate why walking performance declines with ageing.

    Science.gov (United States)

    Song, Seungmoon; Geyer, Hartmut

    2018-04-01

    Although the natural decline in walking performance with ageing affects the quality of life of a growing elderly population, its physiological origins remain unknown. By using predictive neuromechanical simulations of human walking with age-related neuro-musculo-skeletal changes, we find evidence that the loss of muscle strength and muscle contraction speed dominantly contribute to the reduced walking economy and speed. The findings imply that focusing on recovering these muscular changes may be the only effective way to improve performance in elderly walking. More generally, the work is of interest for investigating the physiological causes of altered gait due to age, injury and disorders. Healthy elderly people walk slower and energetically less efficiently than young adults. This decline in walking performance lowers the quality of life for a growing ageing population, and understanding its physiological origin is critical for devising interventions that can delay or revert it. However, the origin of the decline in walking performance remains unknown, as ageing produces a range of physiological changes whose individual effects on gait are difficult to separate in experiments with human subjects. Here we use a predictive neuromechanical model to separately address the effects of common age-related changes to the skeletal, muscular and nervous systems. We find in computer simulations of this model that the combined changes produce gait consistent with elderly walking and that mainly the loss of muscle strength and mass reduces energy efficiency. In addition, we find that the slower preferred walking speed of elderly people emerges in the simulations when adapting to muscle fatigue, again mainly caused by muscle-related changes. The results suggest that a focus on recovering these muscular changes may be the only effective way to improve performance in elderly walking. © 2018 The Authors. The Journal of Physiology © 2018 The Physiological Society.

  4. Healthy Older Adults Have Insufficient Hip Range of Motion and Plantar Flexor Strength to Walk Like Healthy Young Adults

    OpenAIRE

    Anderson, Dennis Earl; Madigan, Michael L.

    2014-01-01

    Limited plantar flexor strength and hip extension range of motion (ROM) in older adults are believed to underlie common age-related differences in gait. However, no studies of age-related differences in gait have quantified the percentage of strength and ROM used during gait. We examined peak hip angles, hip torques and plantar flexor torques, and corresponding estimates of functional capacity utilized (FCU), which we define as the percentage of available strength or joint R...

  5. Strength Training Parallel with Plyometric and Cross training Influences on Speed Endurance

    OpenAIRE

    C.C.Chandra Obul Reddy; Dr. K. Rama Subba Reddy

    2017-01-01

    The purpose of the study was to find out the influence of weight training parallel with plyometric and cross training on speed endurance. To achieve this purpose of the study, forty-five men students studying CSSR & SRRM Degree College, Kamalapuram, YSR (D), Andhra Pradesh, India were randomly selected as subjects during the year 2015-2016. They were divided into three equal groups of fifteen subjects each. Group I underwent weight training parallel with plyometric training for three sessions...

  6. The Effect of Visual Display Properties and Gain Presentation Mode on the Perceived Naturalness of Virtual Walking Speeds

    DEFF Research Database (Denmark)

    Nilsson, Niels Chr.; Serafin, Stefania; Nordahl, Rolf

    2015-01-01

    of the visual speed. The third study found a significant main effect of gain presentation mode. Allowing participants to interactively adjust the gain led to a smaller range of perceptually natural gains and this approach was significantly faster. However, the efficiency may come at the expense of confidence...

  7. Correlation between the bending strength and the thickness interlayer of alumina-mild steel friction welded at lower rotational speed

    International Nuclear Information System (INIS)

    Mohamad Zaky Noh; Luay Bakir Hussain; Zainal Arifin Ahmad

    2007-01-01

    The joining of ceramic-metal could be done through a few techniques: brazing, diffusion bonding, friction welding etc. However, the mechanism of ceramic-metal joining was still not properly understood. In this study, alumina rod was bonded to mild steel rod via friction welding technique by using Al 1100 sheet as interlayer. The diameter of the rods was 10 mm. Friction pressure of 20 MPa and forging pressure of 40 MPa were used. Rotational speeds were maintained at 900 rpm and friction times of 2 to 20 seconds were applied. The joining strength was determined through four point bending test. The maximum bending strength, 240 MPa was obtained at the friction times of 20 seconds. Under optical microscope and SEM observation, the deformation of the aluminum interface was clearly obtained. Mechanical interlocking and close contact between the alumina aluminum and aluminum-mild steel were observed at magnifications of 3000X. The strength of alumina-steel bonding is much dependent on the wettability of the alumina surface by the molten aluminum and the existing of mechanical interlocking between interlayer and sample materials. (Author)

  8. Effects of high intensity resistance aquatic training on body composition and walking speed in women with mild knee osteoarthritis: a 4-month RCT with 12-month follow-up.

    Science.gov (United States)

    Waller, B; Munukka, M; Rantalainen, T; Lammentausta, E; Nieminen, M T; Kiviranta, I; Kautiainen, H; Häkkinen, A; Kujala, U M; Heinonen, A

    2017-08-01

    To investigate the effects of 4-months intensive aquatic resistance training on body composition and walking speed in post-menopausal women with mild knee osteoarthritis (OA), immediately after intervention and after 12-months follow-up. Additionally, influence of leisure time physical activity (LTPA) will be investigated. This randomised clinical trial assigned eighty-seven volunteer postmenopausal women into two study arms. The intervention group (n = 43) participated in 48 supervised intensive aquatic resistance training sessions over 4-months while the control group (n = 44) maintained normal physical activity. Eighty four participants continued into the 12-months' follow-up period. Body composition was measured with dual-energy X-ray absorptiometry (DXA). Walking speed over 2 km and the knee injury and osteoarthritis outcome score (KOOS) were measured. LTPA was recorded with self-reported diaries. After the 4-month intervention there was a significant decrease (P = 0.002) in fat mass (mean change: -1.17 kg; 95% CI: -2.00 to -0.43) and increase (P = 0.002) in walking speed (0.052 m/s; 95% CI: 0.018 to 0.086) in favour of the intervention group. Body composition returned to baseline after 12-months. In contrast, increased walking speed was maintained (0.046 m/s; 95% CI 0.006 to 0.086, P = 0.032). No change was seen in lean mass or KOOS. Daily LTPA over the 16-months had a significant effect (P = 0.007) on fat mass loss (f 2  = 0.05) but no effect on walking speed. Our findings show that high intensity aquatic resistance training decreases fat mass and improves walking speed in post-menopausal women with mild knee OA. Only improvements in walking speed were maintained at 12-months follow-up. Higher levels of LTPA were associated with fat mass loss. ISRCTN65346593. Copyright © 2017 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  9. Design of wheel-type walking-assist device

    International Nuclear Information System (INIS)

    Jung, Seung Ho; Kim, Seung Ho; Kim, Chang Hoi; Seo, Yong Chil; Jung, Kyung Min; Lee, Sung Uk

    2006-03-01

    In this research, a outdoor wheel-type walking-assist device is developed to help an elder having a poor muscular strength at legs for walking, sitting and standing up easily at outdoors, and also for going and downing stairs. In conceptually designing, the environments of an elder's activity, the size of an elder's body and a necessary function of helping an elder are considered. This device has 4 wheels for stability. When an elder walks in incline plane with the proposed device, a rear-wing is rotated to keep the supporting device horizontal, regardless of an angle of inclination. A height-controlling device, which can control the height of the supporting device for adjusting an elder's height, is varied vertically to help an elder to sit and stand-up easily. Moreover, a outdoor wheel-type walking-assist device is conceptually designed and is made. In order to design it, the preview research is investigated firstly. On the basis of the proposed walking-assist device, the outdoor walking-assist device is designed and made. The outdoor wheel-type walking-assist device can go and down stairs automatically. This device go up and down the stair of having maximum 20cm height and an angle of 25 degrees with maximum 4 sec/stairs speed, and move at flatland with 60cm/sec speed

  10. Efficiency of developing 15–17-year weightlifters’ training process for a one-year macrocycle with the use of various speed and strength training methods

    Directory of Open Access Journals (Sweden)

    Oleksandr Piven

    2017-10-01

    Full Text Available Purpose: developed and experimentally tested the construction of the training process of weightlifters of 15–17 years during a one-year macrocycle with the use of various speed and strength training methods. Material & Methods: to the experiment were attracted 30 young weightlifters at the age of 15–17 years, they all had II and III sports categories. Results: it was found that the athletes of the experimental group who used the unconventional training method, using different training regimes – isokinetic, plyometric, half-dynamic, impact method with speed-strength training, which included jumping with various devices in depth and jumping out, after the experiment, they improved their strengths in the amount of the duathlon by 16,5 kg, and also set their own records in contrast to the control group that trained by the traditional method and improved the power results by 7,2 kg. Conclusion: it is established that the use of non-traditional methods for the development of speed-strength qualities of weightlifters, namely, different training regimes – isokinetic, plyometric, half-dynamic, shock method, contributes to the more efficient development of speed-strength qualities, and, consequently, leads to an increase in sports performance in weightlifting.

  11. Kinematic control of walking.

    Science.gov (United States)

    Lacquaniti, F; Ivanenko, Y P; Zago, M

    2002-10-01

    The planar law of inter-segmental co-ordination we described may emerge from the coupling of neural oscillators between each other and with limb mechanical oscillators. Muscle contraction intervenes at variable times to re-excite the intrinsic oscillations of the system when energy is lost. The hypothesis that a law of coordinative control results from a minimal active tuning of the passive inertial and viscoelastic coupling among limb segments is congruent with the idea that movement has evolved according to minimum energy criteria (1, 8). It is known that multi-segment motion of mammals locomotion is controlled by a network of coupled oscillators (CPGs, see 18, 33, 37). Flexible combination of unit oscillators gives rise to different forms of locomotion. Inter-oscillator coupling can be modified by changing the synaptic strength (or polarity) of the relative spinal connections. As a result, unit oscillators can be coupled in phase, out of phase, or with a variable phase, giving rise to different behaviors, such as speed increments or reversal of gait direction (from forward to backward). Supra-spinal centers may drive or modulate functional sets of coordinating interneurons to generate different walking modes (or gaits). Although it is often assumed that CPGs control patterns of muscle activity, an equally plausible hypothesis is that they control patterns of limb segment motion instead (22). According to this kinematic view, each unit oscillator would directly control a limb segment, alternately generating forward and backward oscillations of the segment. Inter-segmental coordination would be achieved by coupling unit oscillators with a variable phase. Inter-segmental kinematic phase plays the role of global control variable previously postulated for the network of central oscillators. In fact, inter-segmental phase shifts systematically with increasing speed both in man (4) and cat (38). Because this phase-shift is correlated with the net mechanical power

  12. Strength Training and Kinematics Parameters of Gait in Healthy Female Elderly

    Directory of Open Access Journals (Sweden)

    Heydar Sadeghi

    2008-10-01

    Full Text Available Objectives: This study was under taken to consider the effect of strength training on some kinematics parameters of gait (step length, cadence and speed walking. Methods & Materials: Twenty-four healthy elderly women (with average and standard deviation age of 61.53±2.84 years, height of 157.1±5.5 cm, weight of 69.13±7.6 kg and BMI 28.1±3.6 kg/m participated in this study. The strength of lower limb assessed using leg press test. The subjects were randomly divided in to control and experimental group. Video camera, 3DMax, Premier and Photoshop soft ware’s were used to measure speed walking, cadence and step length before and after training program. The control group continued their daily activity, while experimental group were in eight weeks for strength training for lower limb and body stabilizer muscles. Within group differences using T-test for independent groups and between group differences were analyzed using by T-test for dependent group before and after training at significant level of 0.05. Results: The changes of speed walking and lower limb strength weren't significant in control group. While significant differences observed in step length and speed walking and lower limb strength in experimental group. In comparison between groups, except of cadence, step length, speed walking and lower limb strength showed significant increase in experimental group. Conclusion: The results confirmed the effectiveness of strength training and increasing lower limb and stabilizer muscles strength on step length and speed walking in healthy elder women.

  13. Effects of Three Types of Exercise Interventions on Healthy Old Adults' Gait Speed : A Systematic Review and Meta-Analysis

    NARCIS (Netherlands)

    Hortobagyi, Tibor; Lesinski, Melanie; Gäbler, Martijn; VanSwearingen, Jessie M.; Malatesta, Davide; Granacher, Urs

    2015-01-01

    Background Habitual walking speed predicts many clinical conditions later in life, but it declines with age. However, which particular exercise intervention can minimize the age-related gait speed loss is unclear. Purpose Our objective was to determine the effects of strength, power, coordination,

  14. A COMPARATIVE STUDY OF PASSIVE SHOULDER ROTATION RANGE OF MOTION, ISOMETRIC ROTATION STRENGTH AND SERVE SPEED BETWEEN ELITE TENNIS PLAYERS WITH AND WITHOUT HISTORY OF SHOULDER PAIN.

    Science.gov (United States)

    Moreno-Pérez, V; Elvira, Jll; Fernandez-Fernandez, J; Vera-Garcia, F J

    2018-02-01

    Glenohumeral internal rotation deficit and external rotation strength have been associated with the development of shoulder pain in overhead athletes. To examine the bilateral passive shoulder rotational range of motion (ROM), the isometric rotational strength and unilateral serve speed in elite tennis players with and without shoulder pain history (PH and NPH, respectively) and compare between dominant and non-dominant limbs and between groups. Cohort study. Fifty-eight elite tennis players were distributed into the PH group (n = 20) and the NPH group (n = 38). Serve velocity, dominant and non-dominant passive shoulder external and internal rotation (ER and IR) ROM, total arc of motion (TAM: the sum of IR and ER ROM), ER and IR isometric strength, bilateral deficits and ER/IR strength ratio were measured in both groups. Questionnaires were administered in order to classify characteristics of shoulder pain. The dominant shoulder showed significantly reduced IR ROM and TAM, and increased ER ROM compared to the non-dominant shoulder in both groups. Isometric ER strength and ER/IR strength ratio were significantly lower in the dominant shoulder in the PH group when compared with the NPH group. No significant differences between groups were found for serve speed. These data show specific adaptations in the IR, TAM and ER ROM in the dominant shoulder in both groups. Isometric ER muscle weakness and ER/IR strength ratio deficit appear to be associated with history of shoulder injuries in elite tennis players. It would be advisable for clinicians to use the present information to design injury prevention programs. 2.

  15. The Effects of the Rope Jump Training Program in Physical Education Lessons on Strength, Speed and VO[subscript 2] Max in Children

    Science.gov (United States)

    Eler, Nebahat; Acar, Hakan

    2018-01-01

    The aim of this study is to examine the effects of rope-jump training program in physical education lessons on strength, speed and VO[subscript 2] max in 10-12 year old boys. 240 male students; rope-jump group (n = 120) and control group (n = 120) participated in the study. Rope-Jump group continued 10 weeks of regular physical education and sport…

  16. Measures of static postural control moderate the association of strength and power with functional dynamic balance.

    Science.gov (United States)

    Forte, Roberta; Boreham, Colin A G; De Vito, Giuseppe; Ditroilo, Massimiliano; Pesce, Caterina

    2014-12-01

    Age-related reductions in strength and power are considered to negatively impact balance control, but the existence of a direct association is still an issue of debate. This is possibly due to the fact that balance assessment is complex, reflects different underlying physiologic mechanisms and involves quantitative measurements of postural sway or timing of performance during balance tasks. The present study evaluated the moderator effect of static postural control on the association of power and strength with dynamic balance tasks. Fifty-seven healthy 65-75 year old individuals performed tests of dynamic functional balance (walking speed under different conditions) and of strength, power and static postural control. Dynamic balance performance (walking speed) was associated with lower limb strength and power, as well as postural control under conditions requiring postural adjustments (narrow surface walking r(2) = 0.31, p balance tasks. Practical implications for assessment and training are discussed.

  17. Nine Walks

    DEFF Research Database (Denmark)

    2013-01-01

    Based on studies of, among others, the Situationists and their theories regarding walks as an artistic method and expression nine master students from “Studio Constructing an Archive”, Aarhus School of Architecture, Denmark performed nine walks as part of the exhibition. These walks relate...... to the students’ individual mappings of Behind the Green Door, its structure and content. They highlight a number of motifs found in the exhibition which are of particular interest to the students. The walks represented reflections on the walk as an artistic method and expression. Each walk is an individual...

  18. The use of relative coupling intervals in horses during walk

    DEFF Research Database (Denmark)

    Olsen, Emil; Pfau, Thilo

    Walking speed varies between over-ground trials and a speed-independent gait-parameter does not exist for use in horses. We introduce relative (R) lateral (L) and diagonal (D) coupling intervals (CI) and hypothesize that both are independent of walking speed. Four horses were walked over 8 Kistler...

  19. Walking economy during cued versus non-cued self-selected treadmill walking in persons with Parkinson's disease.

    Science.gov (United States)

    Gallo, Paul M; McIsaac, Tara L; Garber, Carol Ewing

    2014-01-01

    Gait impairments related to Parkinson's disease (PD) include variable step length and decreased walking velocity, which may result in poorer walking economy. Auditory cueing is a common method used to improve gait mechanics in PD that has been shown to worsen walking economy at set treadmill walking speeds. It is unknown if auditory cueing has the same effects on walking economy at self-selected treadmill walking speeds. To determine if auditory cueing will affect walking economy at self-selected treadmill walking speeds and at speeds slightly faster and slower than self-selected. Twenty-two participants with moderate PD performed three, 6-minute bouts of treadmill walking at three speeds (self-selected and ± 0.22 m·sec-1). One session used cueing and the other without cueing. Energy expenditure was measured and walking economy was calculated (energy expenditure/power). Poorer walking economy and higher energy expenditure occurred during cued walking at a self-selected and a slightly faster walking speed, but there was no apparent difference at the slightly slower speed. These results suggest that potential gait benefits of auditory cueing may come at an energy cost and poorer walking economy for persons with PD at least at some treadmill walking speeds.

  20. Strength Enhancement of Car Front Bumper for Slow Speed Impact by FEA Method as per IIHS Regulation

    Science.gov (United States)

    Sonawane, Chandrakant Rameshchandra; Shelar, Ajit Lavaji

    2017-05-01

    Low speed collisions happen significantly due to on road slow moving heavy traffic as well as during parking of vehicles. The bumpers are provided in front and back side of a vehicle has two main purposes: first is to absorb the energy generated during these kinds of slow speed impacts and secondly to protect the expensive parts like main engine parts, radiators and connected engine cooling mechanism, headlights, taillights, etc, by slowing down the vehicles. The problem often in various cars bumper is that they doesn't line-up vertically during low speed impact and leads to damage of various parts which are costly to repair. Many a times bumper design does not have sufficient capacity to absorb the energy generated during these impact. Guideline by International Institute Highway Safety (IIHS) regulation provides useful insight for such low speed impact study. In this paper, slow speed impact test were conducted as per IIHS regulation in three positions namely central impact, left hand corner impact and right hand corner impact. Parameters including bumper material, shape, thickness and impact condition are analyzed using fine element analysis (FEA) to enhance crashworthiness design in low speed impact. Then the vehicle front structure has been modified suitably. It has been observed that lining up the front metal bumper with suitable stiffness provides the best result which ultimately reduces the damage to the vehicle parts.

  1. Examination of factors affecting gait properties in healthy older adults: focusing on knee extension strength, visual acuity, and knee joint pain.

    Science.gov (United States)

    Demura, Tomohiro; Demura, Shin-ichi; Uchiyama, Masanobu; Sugiura, Hiroki

    2014-01-01

    Gait properties change with age because of a decrease in lower limb strength and visual acuity or knee joint disorders. Gait changes commonly result from these combined factors. This study aimed to examine the effects of knee extension strength, visual acuity, and knee joint pain on gait properties of for 181 healthy female older adults (age: 76.1 (5.7) years). Walking speed, cadence, stance time, swing time, double support time, step length, step width, walking angle, and toe angle were selected as gait parameters. Knee extension strength was measured by isometric dynamometry; and decreased visual acuity and knee joint pain were evaluated by subjective judgment whether or not such factors created a hindrance during walking. Among older adults without vision problems and knee joint pain that affected walking, those with superior knee extension strength had significantly greater walking speed and step length than those with inferior knee extension strength (P pain in both knees showed slower walking speed and longer stance time and double support time. A decrease of knee extension strength and visual acuity and knee joint pain are factors affecting gait in the female older adults. Decreased knee extension strength and knee joint pain mainly affect respective distance and time parameters of the gait.

  2. Comparison between Mother, ActiGraph wGT3X-BT, and a hand tally for measuring steps at various walking speeds under controlled conditions

    DEFF Research Database (Denmark)

    Riel, Henrik; Rathleff, Camilla Rams; Kalstrup, Pernille Møller

    2016-01-01

    Walking is endorsed as health enhancing and is the most common type of physical activity among older adults. Accelerometers are superior to self-reports when measuring steps, however, if they are to be used by clinicians the validity is of great importance. The aim of this study was to investigat...

  3. Effect of elastic band-based high-speed power training on cognitive function, physical performance and muscle strength in older women with mild cognitive impairment.

    Science.gov (United States)

    Yoon, Dong Hyun; Kang, Dongheon; Kim, Hee-Jae; Kim, Jin-Soo; Song, Han Sol; Song, Wook

    2017-05-01

    The effectiveness of resistance training in improving cognitive function in older adults is well demonstrated. In particular, unconventional high-speed resistance training can improve muscle power development. In the present study, the effectiveness of 12 weeks of elastic band-based high-speed power training (HSPT) was examined. Participants were randomly assigned into a HSPT group (n = 14, age 75.0 ± 0.9 years), a low-speed strength training (LSST) group (n = 9, age 76.0 ± 1.3 years) and a control group (CON; n = 7, age 78.0 ± 1.0 years). A 1-h exercise program was provided twice a week for 12 weeks for the HSPT and LSST groups, and balance and tone exercises were carried out by the CON group. Significant increases in levels of cognitive function, physical function, and muscle strength were observed in both the HSPT and LSST groups. In cognitive function, significant improvements in the Mini-Mental State Examination and Montreal Cognitive Assessment were seen in both the HSPT and LSST groups compared with the CON group. In physical functions, Short Physical Performance Battery scores were increased significantly in the HSPT and LSST groups compared with the CON group. In the 12 weeks of elastic band-based training, the HSPT group showed greater improvements in older women with mild cognitive impairment than the LSST group, although both regimens were effective in improving cognitive function, physical function and muscle strength. We conclude that elastic band-based HSPT, as compared with LSST, is more efficient in helping older women with mild cognitive impairment to improve cognitive function, physical performance and muscle strength. Geriatr Gerontol Int 2017; 17: 765-772. © 2016 Japan Geriatrics Society.

  4. Physiotherapy Effects in Gait Speed in Patients with Knee Osteoarthritis.

    Science.gov (United States)

    Tani, Klejda; Kola, Irena; Dhamaj, Fregen; Shpata, Vjollca; Zallari, Kiri

    2018-03-15

    Knee osteoarthritis is a chronic degenerative disease, known as the most common cause of difficulty walking in older adults and subsequently is associated with slow walking. Also one of the main symptoms is a degenerative and mechanics type of pain. Pain is very noticeable while walking in rugged terrain, during ascent and descent of stairs, when changing from sitting to standing position as well as staying in one position for a long time. Many studies have shown that the strength of the quadriceps femoris muscle can affect gait, by improving or weakening it. Kinesio Tape is a physiotherapeutic technique, which reduces pain and increases muscular strength by irritating the skin receptors. The aims of this study was first to verify if the application of Kinesio Tape on quadriceps femoris muscle increases gait speed in patients with knee osteoarthritis and secondly if applying Kinesio Tape on quadriceps femoris muscle reduces pain while walking. Seventy-four patients with primary knee osteoarthritis, aged 50 - 73 years, participated in this study. Firstly we observed the change of gait speed, while walking for 10 meters at normal speed for each patient, before, one day and three days after the application of Kinesio Tape on quadriceps femoris muscle, with the help of the 10 - meter walk test. Secondly, we observed the change of pain, while walking for 10 meters at normal speed for each patient, before, one day and three days after the application, with the help of Numerical Pain Rating Scale - NRS. Our results indicated that there was a significant increase in gait speed while walking for 10 meters one day and also three days after application of Kinesio Tape on quadriceps femoris muscle. Also, there was a significant reduction of pain level 1 and 3 days after application of Kinesio Tape, compared to the level of pain before its application. Our results indicated that there was a significant decrease in pain and increase of gait speed while walking for 10 meters

  5. Random walk on random walks

    NARCIS (Netherlands)

    Hilário, M.; Hollander, den W.Th.F.; Sidoravicius, V.; Soares dos Santos, R.; Teixeira, A.

    2014-01-01

    In this paper we study a random walk in a one-dimensional dynamic random environment consisting of a collection of independent particles performing simple symmetric random walks in a Poisson equilibrium with density ¿¿(0,8). At each step the random walk performs a nearest-neighbour jump, moving to

  6. Tensile bond strength of different adhesive systems to primary dentin treated by Er:YAG laser and conventional high-speed drill

    Science.gov (United States)

    Marques, Barbara A.; Navarro, Ricardo S.; Silvestre, Fellipe D.; Pinheiro, Sergio L.; Freitas, Patricia M.; Imparato, Jose Carlos P.; Oda, Margareth

    2005-03-01

    The aim of this study was to evaluate the tensile strength of different adhesive systems to primary tooth dentin prepared by high-speed drill and Er:YAG laser (2.94μm). Buccal surfaces of 38 primary canines were ground and flattened with sand paper disks (#120-600 grit) and distributed into five groups (n=15): G1: diamond bur in high-speed drill (HD)+ 35% phosphoric acid (PA)+Single Bond (SB); G2: HD+self-etching One Up Bond F (OUB);G3: Er:YAG laser (KaVo 3- LELO-FOUSP)(4Hz, 80mJ, 25,72J/cm2) (L)+PA+SB, G4: L+SB, G5: L+OUB. The inverted truncated cone samples built with Z-100 composite resin after storage in water (37°C/24h) were submitted to tensile bond strength test on Mini Instron 4442 (0.5mm/min, 500N). The data were analyzed with ANOVA and Tukey Test (pHD+PA+SB and HD+OUB (p=0.000), L+SB showed higher values than L+PA+SB and L+OUB (p=0.0311). Er:YAG laser radiation promoted significant increase of bond strength of different adhesive systems evaluated in the dentin of primary teeth.

  7. Criterion-Referenced Values of Grip Strength and Usual Gait Speed Using Instrumental Activities of Daily Living Disability as the Criterion.

    Science.gov (United States)

    Lee, Meng-Chih; Hsu, Chih-Cheng; Tsai, Yi-Fen; Chen, Ching-Yu; Lin, Cheng-Chieh; Wang, Ching-Yi

    Current evidence suggests that grip strength and usual gait speed (UGS) are important predictors of instrumental activities of daily living (IADL) disability. Knowing the optimum cut points of these tests for discriminating people with and without IADL disability could help clinicians or researchers to better interpret the test results and make medical decisions. The purpose of this study was to determine the cutoff values of grip strength and UGS for best discriminating community-dwelling older adults with and without IADL disability, separately for men and women, and to investigate their association with IADL disability. We conducted secondary data analysis on a national dataset collected in the Sarcopenia and Translational Aging Research in Taiwan (START). The data used in this study consisted of health data of 2420 community-dwelling older adults 65 years and older with no history of stroke and with complete data. IADL disability was defined as at least 1 IADL item scored as "need help" or "unable to perform." Receiver operating characteristics analysis was used to estimate the optimum grip strength and UGS cut points for best discriminating older adults with/without IADL disability. The association between each physical performance (grip strength and UGS) and IADL disability was assessed with odds ratios (ORs). With IADL disability as the criterion, the optimal cutoff values of grip strength were 28.7 kg for men and 16.0 kg for women, and those for UGS were 0.76 m/s for men and 0.66 m/s for women. The grip strength test showed satisfactory discriminant validity (area under the curve > 0.7) in men and a strong association with IADL disability (OR > 4). Our cut points using IADL disability as the criterion were close to those indicating frailty or sarcopenia. Our reported cutoffs can serve as criterion-referenced values, along with those previously determined using different indicators, and provide important landmarks on the performance continua of older adults

  8. Nordic Walking Practice Might Improve Plantar Pressure Distribution

    Science.gov (United States)

    Perez-Soriano, Pedro; Llana-Belloch, Salvador; Martinez-Nova, Alfonso; Morey-Klapsing, G.; Encarnacion-Martinez, Alberto

    2011-01-01

    Nordic walking (NW), characterized by the use of two walking poles, is becoming increasingly popular (Morgulec-Adamowicz, Marszalek, & Jagustyn, 2011). We studied walking pressure patterns of 20 experienced and 30 beginner Nordic walkers. Plantar pressures from nine foot zones were measured during trials performed at two walking speeds (preferred…

  9. Walking to health.

    Science.gov (United States)

    Morris, J N; Hardman, A E

    1997-05-01

    Walking is a rhythmic, dynamic, aerobic activity of large skeletal muscles that confers the multifarious benefits of this with minimal adverse effects. Walking, faster than customary, and regularly in sufficient quantity into the 'training zone' of over 70% of maximal heart rate, develops and sustains physical fitness: the cardiovascular capacity and endurance (stamina) for bodily work and movement in everyday life that also provides reserves for meeting exceptional demands. Muscles of the legs, limb girdle and lower trunk are strengthened and the flexibility of their cardinal joints preserved; posture and carriage may improve. Any amount of walking, and at any pace, expends energy. Hence the potential, long term, of walking for weight control. Dynamic aerobic exercise, as in walking, enhances a multitude of bodily processes that are inherent in skeletal muscle activity, including the metabolism of high density lipoproteins and insulin/glucose dynamics. Walking is also the most common weight-bearing activity, and there are indications at all ages of an increase in related bone strength. The pleasurable and therapeutic, psychological and social dimensions of walking, whilst evident, have been surprisingly little studied. Nor has an economic assessment of the benefits and costs of walking been attempted. Walking is beneficial through engendering improved fitness and/or greater physiological activity and energy turnover. Two main modes of such action are distinguished as: (i) acute, short term effects of the exercise; and (ii) chronic, cumulative adaptations depending on habitual activity over weeks and months. Walking is often included in studies of exercise in relation to disease but it has seldom been specifically tested. There is, nevertheless, growing evidence of gains in the prevention of heart attack and reduction of total death rates, in the treatment of hypertension, intermittent claudication and musculoskeletal disorders, and in rehabilitation after heart

  10. The Effect of 12 Weeks Individualized Combined Exercise Rehabilitation Training on Physiological Cost Index (PCI and Walking Speed in Patients with Multiple Sclerosis at all Levels of Physical Disability

    Directory of Open Access Journals (Sweden)

    M Narimani

    2016-11-01

    Full Text Available Background & aim: Most research on the effects of exercise on people with MS rehabilitation exercises sclerosis (MS  have been carried out on patients with low to moderate disability, but research on patients with different severity of disability (physical disability scale of zero to 10 still has to be carefully considered. The aim of this study was to investigate the effects of twelve weeks of rehabilitation exercises personalized compound exercise on physiological cost index (PCI and average speed walking in patients with MS at various levels of disability. Methods: The present research was a semi-experimental practical study. Thus among female patients admitted to the MS Association of Shahrekord city, 96 people were chosen on the basis of physical disability scores and divided into three groups. The first group consisted of less than 5/4 a total of 44 people, the second group between 5/65 and 5/6 up third of each 26 patients were then randomly assigned to an experimental group and a control group. Afterwards each group was divided randomly into an experimental group and a control group. The first group (the scale of disability less than 4.5, N= 44. The second group (the scale of disability 5 - 6.5, N=26. Also 26 patients were in the third group (the scale of disability 6.5 and above. In addition, they were divided into 6 experimental and control groups. Training programs for experimental groups were 12 weeks, three sessions per week and one hour for each session. Factors such as physiological cost index and walking speed were measured with the appropriate tools before and after training. The experimental groups of 1, 2 and 3 each did their own intervention, while the control groups received only stretching exercises. Analysis of data obtained from 96 patients studied was done using descriptive statistics and the analysis of covariance and paired comparing of the adjusted means (P<0.05. ‌‌‌ Results: A significant difference in walking

  11. Gait symmetry and hip strength in women with developmental dysplasia following hip arthroplasty compared to healthy subjects: A cross-sectional study.

    Directory of Open Access Journals (Sweden)

    Ruud A Leijendekkers

    Full Text Available Untreated unilateral developmental dysplasia of the hip (DDH results in asymmetry of gait and hip strength and may lead to early osteoarthritis, which is commonly treated with a total hip arthroplasty (THA. There is limited knowledge about the obtained symmetry of gait and hip strength after the THA. The objectives of this cross-sectional study were to: a identify asymmetries between the operated and non-operated side in kinematics, kinetics and hip strength, b analyze if increased walking speed changed the level of asymmetry in patients c compare these results with those of healthy subjects.Women (18-70 year with unilateral DDH who had undergone unilateral THA were eligible for inclusion. Vicon gait analysis system was used to collect frontal and sagittal plane kinematic and kinetic parameters of the hip joint, pelvis and trunk during walking at comfortable walking speed and increased walking speed. Furthermore, hip abductor and extensor muscle strength was measured.Six patients and eight healthy subjects were included. In the patients, modest asymmetries in lower limb kinematics and kinetics were present during gait, but trunk lateral flexion asymmetry was evident. Patients' trunk lateral flexion also differed compared to healthy subjects. Walking speed did not significantly influence the level of asymmetry. The hip abduction strength asymmetry of 23% was not statistically significant, but the muscle strength of both sides were significantly weaker than those of healthy subjects.In patients with a DDH treated with an IBG THA modest asymmetries in gait kinematics and kinetics were present, with the exception of a substantial asymmetry of the trunk lateral flexion. Increased walking speed did not result in increased asymmetries in gait kinematics and kinetics. Hip muscle strength was symmetrical in patients, but significantly weaker than in healthy subjects. Trunk kinematics should be included as an outcome measure to assess the biomechanical

  12. Effect of low appendicular lean mass, grip strength, and gait speed on the functional outcome after surgery for distal radius fractures.

    Science.gov (United States)

    Roh, Young Hak; Noh, Jung Ho; Gong, Hyun Sik; Baek, Goo Hyun

    2017-12-01

    Patients with low appendicular lean mass plus slow gait speed or weak grip strength are at risk for poor functional recovery after surgery for distal radius fracture, even when they have similar radiologic outcomes. Loss of skeletal muscle mass and consequent loss in muscle function associate with aging, and this condition negatively impacts the activities of daily living and increases elderly individuals' frailty to falls. Thus, patients with low appendicular lean mass would show different functional recovery compared to those without this condition after surgery for distal radius fracture (DRF). This study compares the functional outcomes after surgery for DRF in patients with or without low appendicular lean mass plus slowness or weakness. A total of 157 patients older than 50 years of age with a DRF treated via volar plate fixation were enrolled in this prospective study. A definition of low appendicular lean mass with slowness or weakness was based on the consensus of the Asian Working Group for Sarcopenia. The researchers compared functional assessments (wrist range of motion and Michigan Hand Questionnaire [MHQ]) and radiographic assessments (radial inclination, volar tilt, ulnar variance, and articular congruity) 12 months after surgery between patients with and without low appendicular lean mass plus slowness or weakness. Multivariable regression analyses were performed to determine whether appendicular lean mass, grip strength, gait speed, patient demographic, or injury characteristics accounted for the functional outcomes. Patients with low appendicular lean mass plus slowness or weakness showed a significantly lower recovery of MHQ score than those in the control group throughout 12 months. There was no significant difference in the range of motion between the groups. The radiologic outcomes showed no significant difference between groups in terms of volar tilt, radial inclination, or ulnar variance. According to multivariable regression analysis

  13. Lower limb progressive resistance training improves leg strength but not gait speed or balance in Parkinson's disease: a systematic review and meta-analysis.

    Science.gov (United States)

    Tillman, Alex; Muthalib, Makii; Hendy, Ashlee M; Johnson, Liam G; Rantalainen, Timo; Kidgell, Dawson J; Enticott, Peter G; Teo, Wei-Peng

    2015-01-01

    The use of progressive resistance training (PRT) to improve gait and balance in people with Parkinson's disease (PD) is an emerging area of interest. However, the main effects of PRT on lower limb functions such as gait, balance, and leg strength in people with PD remain unclear. Therefore, the aim of the meta-analysis is to evaluate the evidence surrounding the use of PRT to improve gait and balance in people with PD. Five electronic databases, from inception to December 2014, were searched to identify the relevant studies. Data extraction was performed by two independent reviewers and methodological quality was assessed using the PEDro scale. Standardized mean differences (SMD) and 95% confidence intervals (CIs) of fixed and random effects models were used to calculate the effect sizes between experimental and control groups and I (2) statistics were used to determine levels of heterogeneity. In total, seven studies were identified consisting of 172 participants (experimental n = 84; control n = 88). The pooled results showed a moderate but significant effect of PRT on leg strength (SMD 1.42, 95% CI 0.464-2.376); however, no significant effects were observed for gait speed (SMD 0.418, 95% CI -0.219 to 1.055). No significant effects were observed for balance measures included in this review. In conclusion, our results showed no discernable effect of PRT on gait and balance measures, although this is likely due to the lack of studies available. It may be suggested that PRT be performed in conjunction with balance or task-specific functional training to elicit greater lower limb functional benefits in people with PD.

  14. Lower Limb Progressive Resistance Training Improves Leg Strength but Not Gait Speed or Balance in Parkinson’s Disease: A Systematic Review and Meta-Analysis

    Science.gov (United States)

    Tillman, Alex; Muthalib, Makii; Hendy, Ashlee M.; Johnson, Liam G.; Rantalainen, Timo; Kidgell, Dawson J.; Enticott, Peter G.; Teo, Wei-Peng

    2015-01-01

    The use of progressive resistance training (PRT) to improve gait and balance in people with Parkinson’s disease (PD) is an emerging area of interest. However, the main effects of PRT on lower limb functions such as gait, balance, and leg strength in people with PD remain unclear. Therefore, the aim of the meta-analysis is to evaluate the evidence surrounding the use of PRT to improve gait and balance in people with PD. Five electronic databases, from inception to December 2014, were searched to identify the relevant studies. Data extraction was performed by two independent reviewers and methodological quality was assessed using the PEDro scale. Standardized mean differences (SMD) and 95% confidence intervals (CIs) of fixed and random effects models were used to calculate the effect sizes between experimental and control groups and I2 statistics were used to determine levels of heterogeneity. In total, seven studies were identified consisting of 172 participants (experimental n = 84; control n = 88). The pooled results showed a moderate but significant effect of PRT on leg strength (SMD 1.42, 95% CI 0.464–2.376); however, no significant effects were observed for gait speed (SMD 0.418, 95% CI −0.219 to 1.055). No significant effects were observed for balance measures included in this review. In conclusion, our results showed no discernable effect of PRT on gait and balance measures, although this is likely due to the lack of studies available. It may be suggested that PRT be performed in conjunction with balance or task-specific functional training to elicit greater lower limb functional benefits in people with PD. PMID:25852550

  15. Effect of Body Composition on Walking Economy

    Directory of Open Access Journals (Sweden)

    Maciejczyk Marcin

    2016-12-01

    Full Text Available Purpose. The aim of the study was to evaluate walking economy and physiological responses at two walking speeds in males with similar absolute body mass but different body composition. Methods. The study involved 22 young men with similar absolute body mass, BMI, aerobic performance, calf and thigh circumference. The participants differed in body composition: body fat (HBF group and lean body mass (HLBM group. In the graded test, maximal oxygen uptake (VO2max and maximal heart rate were measured. Walking economy was evaluated during two walks performed at two different speeds (4.8 and 6.0 km ‧ h-1. Results. The VO2max was similar in both groups, as were the physiological responses during slow walking. The absolute oxygen uptake or oxygen uptake relative to body mass did not significantly differentiate the studied groups. The only indicator significantly differentiating the two groups was oxygen uptake relative to LBM. Conclusions. Body composition does not significantly affect walking economy at low speed, while during brisk walking, the economy is better in the HLBM vs. HBF group, provided that walking economy is presented as oxygen uptake relative to LBM. For this reason, we recommend this manner of oxygen uptake normalization in the evaluation of walking economy.

  16. A comparison of at-home walking and 10-meter walking test parameters of individuals with post-stroke hemiparesis.

    Science.gov (United States)

    Nagano, Katsuhito; Hori, Hideaki; Muramatsu, Ken

    2015-02-01

    [Purpose] The purpose of this study was to clarify the difference in gait parameters of at-home walking and the 10-meter walking test results of individuals with hemiparesis. [Subjects] A total of 14 hemiparetic stroke recovery patients participated in this study. Inclusion criteria were: living at home, the ability to walk independently, and demonstrated low extremity on recovery stages III-V on the Brunnstrom Approach. The average age of the subjects was 66 years. [Methods] We used video surveillance and the inked footprint technique to record usual walking speed and maximum speed patterns both in subjects' homes and during the 10-meter walking test. From these methods, walking speed, stride length, and step rate were calculated. [Results] While both usual and maximum walking speeds of the 10-meter walking test correlated with stride length and step rate, at-home walking speeds only significantly correlated with stride length. [Conclusion] Walking patterns of the 10-meter walking test are quantifiably distinct from those demonstrated in patients' homes, and this difference is mainly characterized by stride length. In order to enhance in-home walking ability, exercises that improve length of stride rather than step rate should be recommended.

  17. Progressive strength training (10 RM) commenced immediately after fast-track total knee arthroplasty: is it feasible?

    DEFF Research Database (Denmark)

    Jakobsen, Thomas Linding; Husted, Henrik; Kehlet, Henrik

    2012-01-01

    . They received rehabilitation including progressive strength training of the operated leg (leg press and knee-extension), using relative loads of 10 repetition maximum with three training sessions per week for 2 weeks. Rehabilitation was commenced 1 or 2 days after TKA. At each training session, knee pain, knee...... joint effusion and training load were recorded. Isometric knee-extension strength and maximal walking speed were measured before the first and last session. Results: The training load increased progressively (p training exercises......, but knee pain at rest and knee joint effusion (p training sessions. Isometric knee-extension strength and maximal walking speed increased by 147 and 112%, respectively. Conclusion: Progressive strength training initiated immediately after TKA seems feasible...

  18. Does dynamic stability govern propulsive force generation in human walking?

    Science.gov (United States)

    Browne, Michael G; Franz, Jason R

    2017-11-01

    Before succumbing to slower speeds, older adults may walk with a diminished push-off to prioritize stability over mobility. However, direct evidence for trade-offs between push-off intensity and balance control in human walking, independent of changes in speed, has remained elusive. As a critical first step, we conducted two experiments to investigate: (i) the independent effects of walking speed and propulsive force ( F P ) generation on dynamic stability in young adults, and (ii) the extent to which young adults prioritize dynamic stability in selecting their preferred combination of walking speed and F P generation. Subjects walked on a force-measuring treadmill across a range of speeds as well as at constant speeds while modulating their F P according to a visual biofeedback paradigm based on real-time force measurements. In contrast to improvements when walking slower, walking with a diminished push-off worsened dynamic stability by up to 32%. Rather, we find that young adults adopt an F P at their preferred walking speed that maximizes dynamic stability. One implication of these findings is that the onset of a diminished push-off in old age may independently contribute to poorer balance control and precipitate slower walking speeds.

  19. A randomized trial of functional electrical stimulation for walking in incomplete spinal cord injury: Effects on walking competency.

    Science.gov (United States)

    Kapadia, Naaz; Masani, Kei; Catharine Craven, B; Giangregorio, Lora M; Hitzig, Sander L; Richards, Kieva; Popovic, Milos R

    2014-09-01

    Multi-channel surface functional electrical stimulation (FES) for walking has been used to improve voluntary walking and balance in individuals with spinal cord injury (SCI). To investigate short- and long-term benefits of 16 weeks of thrice-weekly FES-assisted walking program, while ambulating on a body weight support treadmill and harness system, versus a non-FES exercise program, on improvements in gait and balance in individuals with chronic incomplete traumatic SCI, in a randomized controlled trial design. Individuals with traumatic and chronic (≥18 months) motor incomplete SCI (level C2 to T12, American Spinal Cord Injury Association Impairment Scale C or D) were recruited from an outpatient SCI rehabilitation hospital, and randomized to FES-assisted walking therapy (intervention group) or aerobic and resistance training program (control group). Outcomes were assessed at baseline, and after 4, 6, and 12 months. Gait, balance, spasticity, and functional measures were collected. Spinal cord independence measure (SCIM) mobility sub-score improved over time in the intervention group compared with the control group (baseline/12 months: 17.27/21.33 vs. 19.09/17.36, respectively). On all other outcome measures the intervention and control groups had similar improvements. Irrespective of group allocation walking speed, endurance, and balance during ambulation all improved upon completion of therapy, and majority of participants retained these gains at long-term follow-ups. Task-oriented training improves walking ability in individuals with incomplete SCI, even in the chronic stage. Further randomized controlled trials, involving a large number of participants are needed, to verify if FES-assisted treadmill training is superior to aerobic and strength training.

  20. Motor modules in robot-aided walking

    Directory of Open Access Journals (Sweden)

    Gizzi Leonardo

    2012-10-01

    Full Text Available Abstract Background It is hypothesized that locomotion is achieved by means of rhythm generating networks (central pattern generators and muscle activation generating networks. This modular organization can be partly identified from the analysis of the muscular activity by means of factorization algorithms. The activity of rhythm generating networks is described by activation signals whilst the muscle intervention generating network is represented by motor modules (muscle synergies. In this study, we extend the analysis of modular organization of walking to the case of robot-aided locomotion, at varying speed and body weight support level. Methods Non Negative Matrix Factorization was applied on surface electromyographic signals of 8 lower limb muscles of healthy subjects walking in gait robotic trainer at different walking velocities (1 to 3km/h and levels of body weight support (0 to 30%. Results The muscular activity of volunteers could be described by low dimensionality (4 modules, as for overground walking. Moreover, the activation signals during robot-aided walking were bursts of activation timed at specific phases of the gait cycle, underlying an impulsive controller, as also observed in overground walking. This modular organization was consistent across the investigated speeds, body weight support level, and subjects. Conclusions These results indicate that walking in a Lokomat robotic trainer is achieved by similar motor modules and activation signals as overground walking and thus supports the use of robotic training for re-establishing natural walking patterns.

  1. Comparison of Walking, Muscle Strength, Balance, and Fear of Falling Between Repeated Fall Group, One-time Fall Group, and Nonfall Group of the Elderly Receiving Home Care Service.

    Science.gov (United States)

    Jeon, MiYang; Gu, Mee Ock; Yim, JongEun

    2017-12-01

    The purpose of this study was to provide information to develop a program to prevent repeated falls by analyzing the difference in gait, muscle strength, balance, and fear of falling according to their fall experience. The study subjects were 110 elderly individuals aged over 60 years who agreed to their participation in this research. The study participants were categorized into a repeated fall group (n = 40), a one-time fall group (n = 15), and a nonfall group (n = 46) of the elderly. Measurements of gait, muscle strength, balance, and fear of falling were taken in each group. With regard to gait, there were significant differences among three groups in gait cycle (F = 3.50, p = .034), speed (F = 13.06, p balance, the nonfall group had significantly greater results than the one-time fall group and repeated fall group in dynamic balance (F = 10.80, p balance (F = 8.20, p = .001). In the case of the fear of falling, the repeated fall group had significantly higher score than other two groups (F = 20.62, p fall risk factors to enhance gait and balance and lower body muscle strength and reduce the fear of falling to prevent repeated incidences of falls in this population. Copyright © 2017. Published by Elsevier B.V.

  2. Effects of task-specific and impairment-based training compared with usual care on functional walking ability after inpatient stroke rehabilitation: LEAPS Trial.

    Science.gov (United States)

    Nadeau, Stephen E; Wu, Samuel S; Dobkin, Bruce H; Azen, Stanley P; Rose, Dorian K; Tilson, Julie K; Cen, Steven Y; Duncan, Pamela W

    2013-05-01

    After inpatient stroke rehabilitation, many people still cannot participate in community activities because of limited walking ability. To compare the effectiveness of 2 conceptually different, early physical therapy (PT) interventions to usual care (UC) in improving walking 6 months after stroke. The locomotor experience applied post-stroke (LEAPS) study was a single-blind, randomized controlled trial conducted in 408 adults with disabling hemiparetic stroke. Participants were stratified at baseline (2 months) by impairment in walking speed: severe (exercise at home (home exercise program [HEP], n = 126). LTP participants were 18% more likely to transition to a higher functional walking level: severe to >0.4 m/s and moderate to >0.8 m/s than UC participants (95% confidence interval [CI] = 7%-29%), and HEP participants were 17% more likely to transition (95% CI = 5%-29%). Mean gain in walking speed in LTP participants was 0.13 m/s greater (95% CI = 0.09-0.18) and in HEP participants, 0.10 m/s greater (95% CI = 0.05-0.14) than in UC participants. Progressive PT, using either walking training on a treadmill and overground, conducted in a clinic, or strength and balance exercises conducted at home, was superior to UC in improving walking, regardless of severity of initial impairment.

  3. Factors associated with the 6-minute walk test in nursing home residents and community-dwelling older adults

    Science.gov (United States)

    Caballer, Vicent-Benavent; Lisón, Juan Francisco; Rosado-Calatayud, Pedro; Amer-Cuenca, Juan José; Segura-Orti, Eva

    2015-01-01

    [Purpose] The main objective of this study was to determine the contributions and extent to which certain physical measurements explain performance in the 6-minute walk test in healthy older adults living in a geriatric nursing home and for older adults dwelling in the community. [Subjects] The subjects were 122 adults aged 65 and older with no cognitive impairment who were independent in their daily activities. [Methods] The 6-minute walk test, age, body mass index, walking speed, chair stand test, Berg Balance Scale, Timed Up-and-Go test, rectus femoris cross-sectional area, Short Physical Performance Battery, and hand-grip strength were examined. [Results] Strong significant associations were found between mobility, lower-limb function, balance, and the 6-minute walk test. A stepwise multiple regression on the entire sample showed that lower-limb function was a significant and independent predictor for the 6-minute walk test. Additionally, lower-limb function was a strong predictor for the 6-minute walk test in our nursing home group, whereas mobility was found to be the best predictor in our community-dwelling group. [Conclusion] Better lower-limb function, balance, and mobility result in a higher distance covered by healthy older adults. Lower-limb function and mobility appeared to best determine walking performance in the nursing home and community-dwelling groups, respectively. PMID:26696740

  4. Test-retest reliability and minimal detectable change scores for sit-to-stand-to-sit tests, the six-minute walk test, the one-leg heel-rise test, and handgrip strength in people undergoing hemodialysis.

    Science.gov (United States)

    Segura-Ortí, Eva; Martínez-Olmos, Francisco José

    2011-08-01

    Determining the relative and absolute reliability of outcomes of physical performance tests for people undergoing hemodialysis is necessary to discriminate between the true effects of exercise interventions and the inherent variability of this cohort. The aims of this study were to assess the relative reliability of sit-to-stand-to-sit tests (the STS-10, which measures the time [in seconds] required to complete 10 full stands from a sitting position, and the STS-60, which measures the number of repetitions achieved in 60 seconds), the Six-Minute Walk Test (6MWT), the one-leg heel-rise test, and the handgrip strength test and to calculate minimal detectable change (MDC) scores in people undergoing hemodialysis. This study was a prospective, nonexperimental investigation. Thirty-nine people undergoing hemodialysis at 2 clinics in Spain were contacted. Study participants performed the STS-10 (n=37), the STS-60 (n=37), and the 6MWT (n=36). At one of the settings, the participants also performed the one-leg heel-rise test (n=21) and the handgrip strength test (n=12) on both the right and the left sides. Participants attended 2 testing sessions 1 to 2 weeks apart. High intraclass correlation coefficients (≥.88) were found for all tests, suggesting good relative reliability. The MDC scores at 90% confidence intervals were as follows: 8.4 seconds for the STS-10, 4 repetitions for the STS-60, 66.3 m for the 6MWT, 3.4 kg for handgrip strength (force-generating capacity), 3.7 repetitions for the one-leg heel-rise test with the right leg, and 5.2 repetitions for the one-leg heel-rise test with the left leg. Limitations A limited sample of patients was used in this study. The STS-16, STS-60, 6MWT, one-leg heel rise test, and handgrip strength test are reliable outcome measures. The MDC scores at 90% confidence intervals for these tests will help to determine whether a change is due to error or to an intervention.

  5. Isometric muscle strength and mobility capacity in children with cerebral palsy.

    Science.gov (United States)

    Dallmeijer, Annet J; Rameckers, Eugene A; Houdijk, Han; de Groot, Sonja; Scholtes, Vanessa A; Becher, Jules G

    2017-01-01

    To determine the relationship between isometric leg muscle strength and mobility capacity in children with cerebral palsy (CP) compared to typically developing (TD) peers. Participants were 62 children with CP (6-13 years), able to walk with (n = 10) or without (n = 52) walking aids, and 47 TD children. Isometric muscle strength of five muscle groups of the leg was measured using hand-held dynamometry. Mobility capacity was assessed with the 1-min walk, the 10-m walk, sit-to-stand, lateral-step-up and timed-stair tests. Isometric strength of children with CP was reduced to 36-82% of TD. When adjusted for age and height, the percentage of variance in mobility capacity that was explained by isometric strength of the leg muscles was 21-24% (walking speed), 25% (sit-to-stand), 28% (lateral-step-up) and 35% (timed-stair) in children with CP. Hip abductors and knee flexors had the largest contribution to the explained variance, while knee extensors showed the weakest correlation. Weak or no associations were found between strength and mobility capacity in TD children. Isometric strength, especially hip abductor and knee flexor strength, is moderately related to mobility capacity in children with CP, but not in TD children. To what extent training of these muscle groups will lead to better mobility capacity needs further study. Implications for Rehabilitation Strength training in children with cerebral palsy (CP) may be targeted more specifically at hip abductors and knee flexors. The moderate associations imply that large improvements in mobility capacity may not be expected when strength increases.

  6. Merits of using color and shape differentiation to improve the speed and accuracy of drug strength identification on over-the-counter medicines by laypeople.

    Science.gov (United States)

    Hellier, Elizabeth; Tucker, Mike; Kenny, Natalie; Rowntree, Anna; Edworthy, Judy

    2010-09-01

    This study aimed to examine the utility of using color and shape to differentiate drug strength information on over-the-counter medicine packages. Medication errors are an important threat to patient safety, and confusions between drug strengths are a significant source of medication error. A visual search paradigm required laypeople to search for medicine packages of a particular strength from among distracter packages of different strengths, and measures of reaction time and error were recorded. Using color to differentiate drug strength information conferred an advantage on search times and accuracy. Shape differentiation did not improve search times and had only a weak effect on search accuracy. Using color to differentiate drug strength information improves drug strength identification performance. Color differentiation of drug strength information may be a useful way of reducing medication errors and improving patient safety.

  7. Validity of the Nike+ device during walking and running.

    Science.gov (United States)

    Kane, N A; Simmons, M C; John, D; Thompson, D L; Bassett, D R; Basset, D R

    2010-02-01

    We determined the validity of the Nike+ device for estimating speed, distance, and energy expenditure (EE) during walking and running. Twenty trained individuals performed a maximal oxygen uptake test and underwent anthropometric and body composition testing. Each participant was outfitted with a Nike+ sensor inserted into the shoe and an Apple iPod nano. They performed eight 6-min stages on the treadmill, including level walking at 55, 82, and 107 m x min(-1), inclined walking (82 m x min(-1)) at 5 and 10% grades, and level running at 134, 161, and 188 m x min(-1). Speed was measured using a tachometer and EE was measured by indirect calorimetry. Results showed that the Nike+ device overestimated the speed of level walking at 55 m x min(-1) by 20%, underestimated the speed of level walking at 107 m x min(-1) by 12%, but closely estimated the speed of level walking at 82 m x min(-1), and level running at all speeds (pNike+ device overestimated the EE of level walking by 18-37%, but closely estimated the EE of level running (pNike+ in-shoe device provided reasonable estimates of speed and distance during level running at the three speeds tested in this study. However, it overestimated EE during level walking and it did not detect the increased cost of inclined locomotion.

  8. Deep white matter hyperintensities, microstructural integrity and dual task walking in older people.

    Science.gov (United States)

    Ghanavati, Tabassom; Smitt, Myriam Sillevis; Lord, Stephen R; Sachdev, Perminder; Wen, Wei; Kochan, Nicole A; Brodaty, Henry; Delbaere, Kim

    2018-01-03

    To examine neural, physiological and cognitive influences on gait speed under single and dual-task conditions. Sixty-two community-dwelling older people (aged 80.0 ± 4.2 years) participated in our study. Gait speed was assessed with a timed 20-meter walk under single and dual-task (reciting alternate letters of the alphabet) conditions. Participants also underwent tests to estimate physiological fall risk based on five measures of sensorimotor function, cognitive function across five domains, brain white matter (WM) hyperintensities and WM microstructural integrity by measuring fractional anisotropy (FA). Univariate linear regression analyses showed that global physiological and cognitive measures were associated with single (β = 0.594 and β=-0.297, respectively) and dual-task gait speed (β = 0.306 and β=-0.362, respectively). Deep WMHs were associated with dual-task gait speed only (β = 0.257). Multivariate mediational analyses showed that global and executive cognition reduced the strength of the association between deep WMHs and dual-task gait speed by 27% (β = 0.188) and 44% (β = 0.145) respectively. There was a significant linear association between single-task gait speed and mean FA values of the genu (β=-0.295) and splenium (β=-0.326) of the corpus callosum, and between dual-task gait speed and mean FA values of Superior Cerebellar Peduncle (β=-0.284), splenium of the Corpus Callosum (β=-0.286) and Cingulum (β=-0.351). Greater deep WMH volumes are associated with slower walking speed under dual-task conditions, and this relationship is mediated in part by global cognition and executive abilities specifically. Furthermore, both cerebellum and cingulum are related to dual-task walking due to their role in motor skill performance and attention, respectively.

  9. Walking on high heels changes muscle activity and the dynamics of human walking significantly

    DEFF Research Database (Denmark)

    Simonsen, Erik B; Svendsen, Morten Bo Søndergaard; Nørreslet, Andreas

    2012-01-01

    The aim of the study was to investigate the distribution of net joint moments in the lower extremities during walking on high-heeled shoes compared with barefooted walking at identical speed. Fourteen female subjects walked at 4 km/h across three force platforms while they were filmed by five...... digital video cameras operating at 50 frames/second. Both barefooted walking and walking on high-heeled shoes (heel height: 9 cm) were recorded. Net joint moments were calculated by 3D inverse dynamics. EMG was recorded from eight leg muscles. The knee extensor moment peak in the first half of the stance...... phase was doubled when walking on high heels. The knee joint angle showed that high-heeled walking caused the subjects to flex the knee joint significantly more in the first half of the stance phase. In the frontal plane a significant increase was observed in the knee joint abductor moment and the hip...

  10. Give Me Strength.

    Institute of Scientific and Technical Information of China (English)

    维拉

    1996-01-01

    Mort had an absolutely terrible day at the office.Everythingthat could go wrong did go wrong.As he walked home he could beheard muttering strange words to himself:“Oh,give me strength,give me strength.”Mort isn’t asking for the kind of strength thatbuilds strong muscles:he’s asking for the courage or ability to

  11. Functional electrical stimulation-assisted walking for persons with incomplete spinal injuries

    DEFF Research Database (Denmark)

    Ladouceur, M.; Barbeau, H.

    2000-01-01

    This study investigated the changes in maximal overground walking speed (MOWS) that occurred during; walking training with a functional electrical stimulation (FES) orthosis by chronic spinal cord injured persons with incomplete motor function loss. The average walking: speed over a distance of 10...

  12. Allegheny County Walk Scores

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Walk Score measures the walkability of any address using a patented system developed by the Walk Score company. For each 2010 Census Tract centroid, Walk Score...

  13. Toe Walking in Children

    Science.gov (United States)

    ... prone to damage and weaken over time. This diagnosis might be more likely if your child initially walked normally before starting to toe walk. Autism. Toe walking has been linked to autism spectrum ...

  14. Stride rate and walking intensity in healthy older adults.

    Science.gov (United States)

    Peacock, Leslie; Hewitt, Allan; Rowe, David A; Sutherland, Rona

    2014-04-01

    The study investigated (a) walking intensity (stride rate and energy expenditure) under three speed instructions; (b) associations between stride rate, age, height, and walking intensity; and (c) synchronization between stride rate and music tempo during overground walking in a population of healthy older adults. Twenty-nine participants completed 3 treadmill-walking trials and 3 overground-walking trials at 3 self-selected speeds. Treadmill VO2 was measured using indirect calorimetry. Stride rate and music tempo were recorded during overground-walking trials. Mean stride rate exceeded minimum thresholds for moderate to vigorous physical activity (MVPA) under slow (111.41 ± 11.93), medium (118.17 ± 11.43), and fast (123.79 ± 11.61) instructions. A multilevel model showed that stride rate, age, and height have a significant effect (p Music can be a useful way to guide walking cadence.

  15. The Effects of a 12-Week Walking Program on Community-Dwelling Older Adults

    Science.gov (United States)

    Cheng, Shun-Ping; Tsai, Tzu-I; Lii, Yun-Kung; Yu, Shu; Chou, Chen-Liang; Chen, I-Ju

    2009-01-01

    Walking is a popular and easily accessible form of physical activity. However, walking instruction for older adults is based on the evidence gathered from younger populations. This study evaluated walking conditions, strength, balance, and subjective health status after a 12-week walking-training program in community-dwelling adults greater than…

  16. Glucose uptake heterogeneity of the leg muscles is similar between patients with multiple sclerosis and healthy controls during walking.

    Science.gov (United States)

    Kindred, John H; Ketelhut, Nathaniel B; Rudroff, Thorsten

    2015-02-01

    Difficulties in ambulation are one of the main problems reported by patients with multiple sclerosis. A previous study by our research group showed increased recruitment of muscle groups during walking, but the influence of skeletal muscle properties, such as muscle fiber activity, has not been fully elucidated. The purpose of this investigation was to use the novel method of calculating glucose uptake heterogeneity in the leg muscles of patients with multiple sclerosis and compare these results to healthy controls. Eight patients with multiple sclerosis (4 men) and 8 healthy controls (4 men) performed 15 min of treadmill walking at a comfortable self-selected speed following muscle strength tests. Participants were injected with ≈ 8 mCi of [(18)F]-fluorodeoxyglucose during walking after which positron emission tomography/computed tomography imaging was performed. No differences in muscle strength were detected between multiple sclerosis and control groups (P>0.27). Within the multiple sclerosis, group differences in muscle volume existed between the stronger and weaker legs in the vastus lateralis, semitendinosus, and semimembranosus (Pmuscle group or individual muscle of the legs (P>0.16, P≥0.05). Patients with multiple sclerosis and healthy controls showed similar muscle fiber activity during walking. Interpretations of these results, with respect to our previous study, suggest that walking difficulties in patients with multiple sclerosis may be more associated with altered central nervous system motor patterns rather than alterations in skeletal muscle properties. Published by Elsevier Ltd.

  17. Walking for art's sake

    CERN Multimedia

    2005-01-01

    The man who compared himself to a proton ! On 20 May, Gianni Motti went down into the LHC tunnel and walked around the 27 kilometres of the underground ring at an average, unaccelerated pace of 5 kph. This was an artistic rather than an athletic performance, aimed at drawing a parallel between the fantastic speed of the beams produced by the future accelerator and the leisurely stroll of a human. The artist, who hails from Lombardy, was accompanied by cameraman Ivo Zanetti, who filmed the event from start to finish, and physicist Jean-Pierre Merlo. The first part of the film can be seen at the Villa Bernasconi, 8 route du Grand-Lancy, Grand Lancy, until 26 June.

  18. Walking for art's sake

    CERN Multimedia

    2005-01-01

      The man who compared himself to a proton ! On 20 May, Gianni Motti went down into the LHC tunnel and walked around the 27 kilometres of the underground ring at an average, unaccelerated pace of 5 kph. This was an artistic rather than an athletic performance, aimed at drawing a parallel between the fantastic speed of the beams produced by the future accelerator and the leisurely stroll of a human. The artist, who hails from Lombardy, was accompanied by cameraman Ivo Zanetti, who filmed the event from start to finish, and physicist Jean-Pierre Merlo. The first part of the film can be seen at the Villa Bernasconi, 8 route du Grand-Lancy, Grand Lancy, until 26 June.

  19. Effect of uphill and downhill walking on walking performance in geriatric patients using a wheeled walker.

    Science.gov (United States)

    Lindemann, Ulrich; Schwenk, Michael; Schmitt, Syn; Weyrich, Michael; Schlicht, Wolfgang; Becker, Clemens

    2017-08-01

    Wheeled walkers are recommended to improve walking performance in older persons and to encourage and assist participation in daily life. Nevertheless, using a wheeled walker can cause serious problems in the natural environment. This study aimed to compare uphill and downhill walking with walking level in geriatric patients using a wheeled walker. Furthermore, we investigated the effect of using a wheeled walker with respect to dual tasking when walking level. A total of 20 geriatric patients (median age 84.5 years) walked 10 m at their habitual pace along a level surface, uphill and downhill, with and without a standard wheeled walker. Gait speed, stride length and cadence were assessed by wearable sensors and the walk ratio was calculated. When using a wheeled walker while walking level the walk ratio improved (0.58 m/[steps/min] versus 0.57 m/[steps/min], p = 0.023) but gait speed decreased (1.07 m/s versus 1.12 m/s, p = 0.020) when compared to not using a wheeled walker. With respect to the walk ratio, uphill and downhill walking with a wheeled walker decreased walking performance when compared to level walking (0.54 m/[steps/min] versus 0.58 m/[steps/min], p = 0.023 and 0.55 m/[steps/min] versus 0.58 m/[steps/min], p = 0.001, respectively). At the same time, gait speed decreased (0.079 m/s versus 1.07 m/s, p walker improved the quality of level walking but the performance of uphill and downhill walking was worse compared to walking level when using a wheeled walker.

  20. Fire-Walking

    Science.gov (United States)

    Willey, David

    2010-01-01

    This article gives a brief history of fire-walking and then deals with the physics behind fire-walking. The author has performed approximately 50 fire-walks, took the data for the world's hottest fire-walk and was, at one time, a world record holder for the longest fire-walk (www.dwilley.com/HDATLTW/Record_Making_Firewalks.html). He currently…

  1. Relationship between quantum walks and relativistic quantum mechanics

    International Nuclear Information System (INIS)

    Chandrashekar, C. M.; Banerjee, Subhashish; Srikanth, R.

    2010-01-01

    Quantum walk models have been used as an algorithmic tool for quantum computation and to describe various physical processes. This article revisits the relationship between relativistic quantum mechanics and the quantum walks. We show the similarities of the mathematical structure of the decoupled and coupled forms of the discrete-time quantum walk to that of the Klein-Gordon and Dirac equations, respectively. In the latter case, the coin emerges as an analog of the spinor degree of freedom. Discrete-time quantum walk as a coupled form of the continuous-time quantum walk is also shown by transforming the decoupled form of the discrete-time quantum walk to the Schroedinger form. By showing the coin to be a means to make the walk reversible and that the Dirac-like structure is a consequence of the coin use, our work suggests that the relativistic causal structure is a consequence of conservation of information. However, decoherence (modeled by projective measurements on position space) generates entropy that increases with time, making the walk irreversible and thereby producing an arrow of time. The Lieb-Robinson bound is used to highlight the causal structure of the quantum walk to put in perspective the relativistic structure of the quantum walk, the maximum speed of walk propagation, and earlier findings related to the finite spread of the walk probability distribution. We also present a two-dimensional quantum walk model on a two-state system to which the study can be extended.

  2. Race walking gait and its influence on race walking economy in world-class race walkers.

    Science.gov (United States)

    Gomez-Ezeiza, Josu; Torres-Unda, Jon; Tam, Nicholas; Irazusta, Jon; Granados, Cristina; Santos-Concejero, Jordan

    2018-03-06

    The aim of this study was to determine the relationships between biomechanical parameters of the gait cycle and race walking economy in world-class Olympic race walkers. Twenty-One world-class race walkers possessing the Olympic qualifying standard participated in this study. Participants completed an incremental race walking test starting at 10 km·h -1 , where race walking economy (ml·kg -1 ·km -1 ) and spatiotemporal gait variables were analysed at different speeds. 20-km race walking performance was related to race walking economy, being the fastest race walkers those displaying reduced oxygen cost at a given speed (R = 0.760, p < 0.001). Longer ground contact times, shorter flight times, longer midstance sub-phase and shorter propulsive sub-phase during stance were related to a better race walking economy (moderate effect, p < 0.05). According to the results of this study, the fastest race walkers were more economi cal than the lesser performers. Similarly, shorter flight times are associated with a more efficient race walking economy. Coaches and race walkers should avoid modifying their race walking style by increasing flight times, as it may not only impair economy, but also lead to disqualification.

  3. Randomized random walk on a random walk

    International Nuclear Information System (INIS)

    Lee, P.A.

    1983-06-01

    This paper discusses generalizations of the model introduced by Kehr and Kunter of the random walk of a particle on a one-dimensional chain which in turn has been constructed by a random walk procedure. The superimposed random walk is randomised in time according to the occurrences of a stochastic point process. The probability of finding the particle in a particular position at a certain instant is obtained explicitly in the transform domain. It is found that the asymptotic behaviour for large time of the mean-square displacement of the particle depends critically on the assumed structure of the basic random walk, giving a diffusion-like term for an asymmetric walk or a square root law if the walk is symmetric. Many results are obtained in closed form for the Poisson process case, and these agree with those given previously by Kehr and Kunter. (author)

  4. Effects of different strength training frequencies on maximum strength, body composition and functional capacity in healthy older individuals.

    Science.gov (United States)

    Turpela, Mari; Häkkinen, Keijo; Haff, Guy Gregory; Walker, Simon

    2017-11-01

    There is controversy in the literature regarding the dose-response relationship of strength training in healthy older participants. The present study determined training frequency effects on maximum strength, muscle mass and functional capacity over 6months following an initial 3-month preparatory strength training period. One-hundred and six 64-75year old volunteers were randomly assigned to one of four groups; performing strength training one (EX1), two (EX2), or three (EX3) times per week and a non-training control (CON) group. Whole-body strength training was performed using 2-5 sets and 4-12 repetitions per exercise and 7-9 exercises per session. Before and after the intervention, maximum dynamic leg press (1-RM) and isometric knee extensor and plantarflexor strength, body composition and quadriceps cross-sectional area, as well as functional capacity (maximum 7.5m forward and backward walking speed, timed-up-and-go test, loaded 10-stair climb test) were measured. All experimental groups increased leg press 1-RM more than CON (EX1: 3±8%, EX2: 6±6%, EX3: 10±8%, CON: -3±6%, Ptraining frequency would induce greater benefit to maximum walking speed (i.e. functional capacity) despite a clear dose-response in dynamic 1-RM strength, at least when predominantly using machine weight-training. It appears that beneficial functional capacity improvements can be achieved through low frequency training (i.e. 1-2 times per week) in previously untrained healthy older participants. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Effect of Metformin on Handgrip Strength, Gait Speed, Myostatin Serum Level, and Health-related Quality of Life: A Double Blind Randomized Controlled Trial among Non-diabetic Pre-frail Elderly Patients.

    Science.gov (United States)

    Laksmi, Purwita Wijaya; Setiati, Siti; Tamin, Tirza Z; Soewondo, Pradana; Rochmah, Wasilah; Nafrialdi, Nafrialdi; Prihartono, Joedo

    2017-04-01

    sarcopenia contributes to the development of frailty syndrome. Frailty syndrome is potentially improved by modifying insulin resistance, inflammation, and myostatin level. This study is aimed to investigate the effect of metformin on handgrip strength, gait speed, myostatin serum level, and health-related quality of life (HR-QoL) among non-diabetic pre-frail elderly patients. a double blind randomized controlled trial study was conducted on non-diabetic elderly outpatients aged ≥ 60 years with pre-frail status based on phenotype and/ or index criteria (Cardiovascular Health Study and/ or Frailty Index 40 items) consecutively recruited from March 2015 to June 2016 at Cipto Mangunkusumo Hospital. One-hundred-twenty subjects who met the research criteria were randomized and equally assigned into 3 x 500 mg metformin or placebo group. The study outcomes were measured at baseline and after 16 weeks of intervention. out of 120 subjects, 43 subjects in metformin group and 48 subjects in placebo group who completed the intervention. There was a significant improvement on the mean gait speed of metformin group by 0.39 (0.77) second or 0.13 (0.24) meter/second that remained significant after adjusting for important prognostic factors (p = 0.024). There was no significant difference on handgrip strength, myostatin serum level, and HR-QoL between both groups. 3 x 500 mg metformin for 16 weeks was statistically significant and clinically important in improving usual gait speed as one of the HR-QoL dimensions, but did not significantly improve the EQ-5D index score, handgrip strength, nor myostatin serum level.

  6. Relation between random walks and quantum walks

    Science.gov (United States)

    Boettcher, Stefan; Falkner, Stefan; Portugal, Renato

    2015-05-01

    Based on studies of four specific networks, we conjecture a general relation between the walk dimensions dw of discrete-time random walks and quantum walks with the (self-inverse) Grover coin. In each case, we find that dw of the quantum walk takes on exactly half the value found for the classical random walk on the same geometry. Since walks on homogeneous lattices satisfy this relation trivially, our results for heterogeneous networks suggest that such a relation holds irrespective of whether translational invariance is maintained or not. To develop our results, we extend the renormalization-group analysis (RG) of the stochastic master equation to one with a unitary propagator. As in the classical case, the solution ρ (x ,t ) in space and time of this quantum-walk equation exhibits a scaling collapse for a variable xdw/t in the weak limit, which defines dw and illuminates fundamental aspects of the walk dynamics, e.g., its mean-square displacement. We confirm the collapse for ρ (x ,t ) in each case with extensive numerical simulation. The exact values for dw themselves demonstrate that RG is a powerful complementary approach to study the asymptotics of quantum walks that weak-limit theorems have not been able to access, such as for systems lacking translational symmetries beyond simple trees.

  7. Daily intermittent hypoxia enhances walking after chronic spinal cord injury

    Science.gov (United States)

    Hayes, Heather B.; Jayaraman, Arun; Herrmann, Megan; Mitchell, Gordon S.; Rymer, William Z.

    2014-01-01

    Objectives: To test the hypothesis that daily acute intermittent hypoxia (dAIH) and dAIH combined with overground walking improve walking speed and endurance in persons with chronic incomplete spinal cord injury (iSCI). Methods: Nineteen subjects completed the randomized, double-blind, placebo-controlled, crossover study. Participants received 15, 90-second hypoxic exposures (dAIH, fraction of inspired oxygen [Fio2] = 0.09) or daily normoxia (dSHAM, Fio2 = 0.21) at 60-second normoxic intervals on 5 consecutive days; dAIH was given alone or combined with 30 minutes of overground walking 1 hour later. Walking speed and endurance were quantified using 10-Meter and 6-Minute Walk Tests. The trial is registered at ClinicalTrials.gov (NCT01272349). Results: dAIH improved walking speed and endurance. Ten-Meter Walk time improved with dAIH vs dSHAM after 1 day (mean difference [MD] 3.8 seconds, 95% confidence interval [CI] 1.1–6.5 seconds, p = 0.006) and 2 weeks (MD 3.8 seconds, 95% CI 0.9–6.7 seconds, p = 0.010). Six-Minute Walk distance increased with combined dAIH + walking vs dSHAM + walking after 5 days (MD 94.4 m, 95% CI 17.5–171.3 m, p = 0.017) and 1-week follow-up (MD 97.0 m, 95% CI 20.1–173.9 m, p = 0.014). dAIH + walking increased walking distance more than dAIH after 1 day (MD 67.7 m, 95% CI 1.3–134.1 m, p = 0.046), 5 days (MD 107.0 m, 95% CI 40.6–173.4 m, p = 0.002), and 1-week follow-up (MD 136.0 m, 95% CI 65.3–206.6 m, p walking improved walking speed and distance in persons with chronic iSCI. The impact of dAIH is enhanced by combination with walking, demonstrating that combinatorial therapies may promote greater functional benefits in persons with iSCI. Classification of evidence: This study provides Class I evidence that transient hypoxia (through measured breathing treatments), along with overground walking training, improves walking speed and endurance after iSCI. PMID:24285617

  8. Steady and transient coordination structures of walking and running

    NARCIS (Netherlands)

    Lamoth, C.J.C.; Daffertshofer, A.; Huys, R.; Beek, P.J.

    2009-01-01

    We studied multisegmental coordination and stride characteristics in nine participants while walking and running on a treadmill. The study's main aim was to evaluate the coordination patterns of walking and running and their variance as a function of locomotion speed, with a specific focus on gait

  9. Steady and transient coordination structures of walking and running

    NARCIS (Netherlands)

    Lamoth, C. J. C.; Daffertshofer, A.; Huys, R.; Beek, P. J.

    We studied multisegmental coordination and stride characteristics in nine participants while walking and running on a treadmill. The study's main aim was to evaluate the coordination patterns of walking and running and their variance as a function of locomotion speed, with a specific focus on gait

  10. Elastic coupling of limb joints enables faster bipedal walking

    Science.gov (United States)

    Dean, J.C.; Kuo, A.D.

    2008-01-01

    The passive dynamics of bipedal limbs alone are sufficient to produce a walking motion, without need for control. Humans augment these dynamics with muscles, actively coordinated to produce stable and economical walking. Present robots using passive dynamics walk much slower, perhaps because they lack elastic muscles that couple the joints. Elastic properties are well known to enhance running gaits, but their effect on walking has yet to be explored. Here we use a computational model of dynamic walking to show that elastic joint coupling can help to coordinate faster walking. In walking powered by trailing leg push-off, the model's speed is normally limited by a swing leg that moves too slowly to avoid stumbling. A uni-articular spring about the knee allows faster but uneconomical walking. A combination of uni-articular hip and knee springs can speed the legs for improved speed and economy, but not without the swing foot scuffing the ground. Bi-articular springs coupling the hips and knees can yield high economy and good ground clearance similar to humans. An important parameter is the knee-to-hip moment arm that greatly affects the existence and stability of gaits, and when selected appropriately can allow for a wide range of speeds. Elastic joint coupling may contribute to the economy and stability of human gait. PMID:18957360

  11. Implementing quantum walks using orbital angular momentum of classical light

    CSIR Research Space (South Africa)

    Goyal, SK

    2013-06-01

    Full Text Available –5]. This speed up gained in quantum walks promises ad- vantages when applied in quantum computation for cer- tain classes of quantum algorithms [6], for example, quan- tum search algorithms [7, 8]. Quantum walks have also been used to analyze energy transport...

  12. Relativistically speaking: Let's walk or run through the rain?

    OpenAIRE

    Assis, Armando V. D. B.

    2010-01-01

    We analyse under a simple approach the problem one must decide the best strategy to minimize the contact with rain when moving between two points through the rain. The available strategies: walk (low speed boost $

  13. More Adults Are Walking

    Centers for Disease Control (CDC) Podcasts

    This podcast is based on the August 2012 CDC Vital Signs report. While more adults are walking, only half get the recommended amount of physical activity. Listen to learn how communities, employers, and individuals may help increase walking.

  14. Influence of the swing ankle angle on walking stability for a passive dynamic walking robot with flat feet

    Directory of Open Access Journals (Sweden)

    Xizhe Zang

    2016-03-01

    Full Text Available To achieve high walking stability for a passive dynamic walking robot is not easy. In this article, we aim to investigate whether the walking performance for a passive dynamic walking robot can be improved by just simply changing the swing ankle angle before impact. To validate this idea, a passive bipedal walking model with two straight legs, two flat feet, a hip joint, and two ankle joints was built in this study. The walking dynamics that contains double stance phase was derived. By numerical simulation of the walking in MATLAB, we found that the walking performance can be adjusted effectively by only simply changing the swing ankle angle before impact. A bigger swing ankle angle in a reasonable range will lead to a higher walking stability and a lower initial walking speed of the next step. A bigger swing ankle angle before impact leads to a bigger amount of energy lost during impact for the quasi-passive dynamic walking robot which will influence the walking stability of the next step.

  15. Changes in gait and posture as factors of dynamic stability during walking in pregnancy.

    Science.gov (United States)

    Krkeljas, Zarko

    2018-04-01

    Changes in gait and postural control during pregnancy may lead to increased fall rates during walking relative to non-pregnant women. Due to lack of empirical evidence on balance and postural control in dynamic conditions, the primary aim of this study was investigate the changes in gait and postural control as factors of stability during walking. Gait and posture of thirty-five (35) pregnant women (27 ± 6.1 years) were analysed at self-selected walking speed, and at different stage of pregnancy. The results indicate that although the gait kinematics did not differ between the trimesters, significant associations were noted between the step width, the lateral trunk lean, and the medio-lateral deviations in centre of gravity and centre of pressure. In contrast to the static conditions, anterior-posterior postural sway is not present during walking, whereas the lateral trunk lean is the primary factor women use in pregnancy to keep the centre of gravity closer to the base of support. Postural changes and those in gait kinematics were largely affected by the relative mass gain, rather than the absolute mass. Considering the importance of relative mass gain, more attention during healthy pregnancy should be given to monitoring the timing of onset of musculoskeletal changes, and design of antenatal exercise programs targeting core strength and pelvic stability. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Validity and reliability of isometric, isokinetic and isoinertial modalities for the assessment of quadriceps muscle strength in patients with total knee arthroplasty.

    Science.gov (United States)

    Lienhard, K; Lauermann, S P; Schneider, D; Item-Glatthorn, J F; Casartelli, N C; Maffiuletti, N A

    2013-12-01

    Reliability of isometric, isokinetic and isoinertial modalities for quadriceps strength evaluation, and the relation between quadriceps strength and physical function was investigated in 29 total knee arthroplasty (TKA) patients, with an average age of 63 years. Isometric maximal voluntary contraction torque, isokinetic peak torque, and isoinertial one-repetition maximum load of the involved and uninvolved quadriceps were evaluated as well as objective (walking parameters) and subjective physical function (WOMAC). Reliability was good and comparable for the isometric, isokinetic, and isoinertial strength outcomes on both sides (intraclass correlation coefficient range: 0.947-0.966; standard error of measurement range: 5.1-9.3%). Involved quadriceps strength was significantly correlated to walking speed (r range: 0.641-0.710), step length (r range: 0.685-0.820) and WOMAC function (r range: 0.575-0.663), independent from the modality (P strength was also significantly correlated to walking speed (r range: 0.413-0.539), step length (r range: 0.514-0.608) and WOMAC function (r range: 0.374-0.554) (P 0.05). In conclusion, isometric, isokinetic, and isoinertial modalities ensure valid and reliable assessment of quadriceps muscle strength in TKA patients. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Quantum walk computation

    International Nuclear Information System (INIS)

    Kendon, Viv

    2014-01-01

    Quantum versions of random walks have diverse applications that are motivating experimental implementations as well as theoretical studies. Recent results showing quantum walks are “universal for quantum computation” relate to algorithms, to be run on quantum computers. We consider whether an experimental implementation of a quantum walk could provide useful computation before we have a universal quantum computer

  18. Walk-Startup of a Two-Legged Walking Mechanism

    Science.gov (United States)

    Babković, Kalman; Nagy, László; Krklješ, Damir; Borovac, Branislav

    There is a growing interest towards humanoid robots. One of their most important characteristic is the two-legged motion - walk. Starting and stopping of humanoid robots introduce substantial delays. In this paper, the goal is to explore the possibility of using a short unbalanced state of the biped robot to quickly gain speed and achieve the steady state velocity during a period shorter than half of the single support phase. The proposed method is verified by simulation. Maintainig a steady state, balanced gait is not considered in this paper.

  19. Walking-Beam Solar-Cell Conveyor

    Science.gov (United States)

    Feder, H.; Frasch, W.

    1982-01-01

    Microprocessor-controlled walking-beam conveyor moves cells between work stations in automated assembly line. Conveyor has arm at each work station. In unison arms pick up all solar cells and advance them one station; then beam retracks to be in position for next step. Microprocessor sets beam stroke, speed, and position.

  20. Different instructions during the ten-meter walking test determined significant increases in maximum gait speed in individuals with chronic hemiparesis Diferentes instruções durante teste de velocidade de marcha determinam aumento significativo na velocidade máxima de indivíduos com hemiparesia crônica

    Directory of Open Access Journals (Sweden)

    Lucas R. Nascimento

    2012-04-01

    Full Text Available OBJECTIVE: To evaluate the effects of different instructions for the assessment of maximum walking speed during the ten-meter walking test with chronic stroke subjects. METHODS: Participants were instructed to walk under four experimental conditions: (1 comfortable speed, (2 maximum speed (simple verbal command, (3 maximum speed (modified verbal command-"catch a bus" and (4 maximum speed (verbal command + demonstration. Participants walked three times in each condition and the mean time to cover the intermediate 10 meters of a 14-meter corridor was registered to calculate the gait speed (m/s. Repeated-measures ANOVAs, followed by planned contrasts, were employed to investigate differences between the conditions (α=5%. Means, standard deviations and 95% confidence intervals (CI were calculated. RESULTS: The mean values for the four conditions were: (1 0.74m/s; (2 0.85 m/s; (3 0.93 m/s; (4 0.92 m/s, respectively, with significant differences between the conditions (F=40.9; pOBJETIVO: Avaliar os efeitos de diferentes instruções para avaliação da velocidade de marcha máxima de indivíduos hemiparéticos durante o teste de caminhada de 10 metros. MÉTODOS: Os indivíduos deambularam em quatro condições experimentais: (1 velocidade habitual, (2 velocidade máxima (comando verbal simples, (3 velocidade máxima (comando verbal modificado: pegar ônibus, (4 velocidade máxima (comando verbal + demonstração. Solicitou-se a cada participante que deambulasse três vezes em cada condição, e a média do tempo necessário para percorrer os 10 metros intermediários de um corredor de 14 metros foi utilizada para cálculo da velocidade (m/s. A ANOVA de medidas repetidas, com contrastes pré-planejados, foi utilizada para comparação dos dados (α=5%, sendo apresentados valores de média, desvio-padrão e intervalos de confiança (IC de 95%. RESULTADOS: As médias de velocidade para as quatro condições foram: (1 0,74m/s; (2 0,85m/s; (3 0,93m/s; (4

  1. Inferring the high-pressure strength of copper by measurement of longitudinal sound speed in a symmetric impact and release experiment

    Science.gov (United States)

    Rothman, Stephen; Edwards, Rhys; Vogler, Tracy J.; Furnish, M. D.

    2012-03-01

    Velocity-time histories of free- or windowed-surfaces have been used to calculate wave speeds and hence deduce the shear moduli for materials at high pressure. This is important to high velocity impact phenomena, e.g. shaped-charge jets, long rod penetrators, and other projectile/armour interactions. Historically the shock overtake method has required several experiments with different depths of material to account for the effect of the surface on the arrival time of the release. A characteristics method, previously used for analysis of isentropic compression experiments, has been modified to account for the effect of the surface interactions, thus only one depth of material is required. This analysis has been applied to symmetric copper impacts performed at Sandia National Laboratory's Star Facility. A shear modulus of 200GPa, at a pressure of ~180GPa, has been estimated. These results are in broad agreement with previous work by Hayes et al.

  2. Human H-reflexes are smaller in difficult beam walking than in normal treadmill walking.

    Science.gov (United States)

    Llewellyn, M; Yang, J F; Prochazka, A

    1990-01-01

    Hoffman (H) reflexes were elicited from the soleus (SOL) muscle while subjects walked on a treadmill and on a narrow beam (3.5 cm wide, raised 34 cm from the floor). The speed of walking on the treadmill was selected for each subject to match the background activation level of their SOL muscle during beam walking. The normal reciprocal activation pattern of the tibialis anterior and SOL muscles in treadmill walking was replaced by a pattern dominated by co-contraction on the beam. In addition, the step cycle duration was more variable and the time spent in the swing phase was reduced on the beam. The H-reflexes were highly modulated in both tasks, the amplitude being high in the stance phase and low in the swing phase. The H-reflex amplitude was on average 40% lower during beam walking than treadmill walking. The relationship between the H-reflex amplitude and the SOL EMG level was quantified by a regression line relating the two variables. The slope of this line was on average 41% lower in beam walking than treadmill walking. The lower H-reflex gain observed in this study and the high level of fusimotor drive observed in cats performing similar tasks suggest that the two mechanisms which control the excitability of this reflex pathway (i.e. fusimotor action and control of transmission at the muscle spindle to moto-neuron synapse) may be controlled independently.

  3. Aerobic treadmill plus Bobath walking training improves walking in subacute stroke: a randomized controlled trial.

    Science.gov (United States)

    Eich, H-J; Mach, H; Werner, C; Hesse, S

    2004-09-01

    To evaluate the immediate and long-term effects of aerobic treadmill plus Bobath walking training in subacute stroke survivors compared with Bobath walking training alone. Randomized controlled trial. Rehabilitation unit. Fifty patients, first-time supratentorial stroke, stroke interval less than six weeks, Barthel Index (0-100) from 50 to 80, able to walk a minimum distance of 12 m with either intermittent help or stand-by while walking, cardiovascular stable, minimum 50 W in the bicycle ergometry, randomly allocated to two groups, A and B. Group A 30 min of treadmill training, harness secured and minimally supported according to patients' needs, and 30 min of physiotherapy, every workday for six weeks, speed and inclination of the treadmill were adjusted to achieve a heart rate of HR: (Hrmax-HRrest)*0.6+HRrest; in group B 60 min of daily physiotherapy for six weeks. Primary outcome variables were the absolute improvement of walking velocity (m/s) and capacity (m), secondary were gross motor function including walking ability (score out of 13) and walking quality (score out of 41), blindly assessed before and after the intervention, and at follow-up three months later. Patients tolerated the aerobic training well with no side-effects, significantly greater improvement of walking velocity and capacity both at study end (p =0.001 versus p =0.002) and at follow-up (p Bobath walking training in moderately affected stroke patients was better than Bobath walking training alone with respect to the improvement of walking velocity and capacity. The treatment approach is recommended in patients meeting the inclusion criteria. A multicentre trial should follow to strengthen the evidence.

  4. Detection of Abnormal Muscle Activations during Walking Following Spinal Cord Injury (SCI)

    Science.gov (United States)

    Wang, Ping; Low, K. H.; McGregor, Alison H.; Tow, Adela

    2013-01-01

    In order to identify optimal rehabilitation strategies for spinal cord injury (SCI) participants, assessment of impaired walking is required to detect, monitor and quantify movement disorders. In the proposed assessment, ten healthy and seven SCI participants were recruited to perform an over-ground walking test at slow walking speeds. SCI…

  5. Physical demands on young elite European female basketball players with special reference to speed, agility, explosive strength, and take-off power.

    Science.gov (United States)

    Erčulj, Frane; Blas, Mateja; Bračič, Mitja

    2010-11-01

    The aim of the study was to determine and analyze the level of certain motor abilities (acceleration and agility, the explosive strength of arms, and take-off power) of young elite European female basketball players. We also wanted to establish whether there were any differences between 3 groups of female basketball players who differed in terms of their playing performance. The sample of subjects consists of 65 female basketball players aged 14.49 (± 0.61) years who were divided into 3 groups (divisions A, B, and C of the European Championships). We compare the groups by using 8 motor tests. p Values training status, this is also 1 of the key reasons for these players' lower playing efficiency compared to those from divisions A and B. We hope the findings of this study will enable the generation of model values, which can assist basketball coaches for this age category in basketball clubs, high schools, national teams, and basketball camps.

  6. Effects of temperature and loading speed on interface-dominated strength in fibre/polymer composites: An evaluation for in-situ environment

    International Nuclear Information System (INIS)

    Sethi, Sanghamitra; Rathore, Dinesh Kumar; Ray, Bankim Chandra

    2015-01-01

    Graphical abstract: Some microcracks turn to potential cracks at low loading rates and cause significant reduction in interlaminar shear strength of the composite system while as the loading rate increases the time available to propagate the microcracks is less. This can be attributed to higher ILSS at higher loading rates at these above-ambient temperatures. - Highlights: • Effect of temperature and loading rate has been studied. • Three different types of fibres are used for fabrication. • Flexural and fractography behaviour were studied. • T g was affected by types of fibre and matrix used. - Abstract: The present investigation intends to study the influence of crosshead velocity and in-situ environmental conditioning i.e. high temperature and cryogenic temperature on micromechanical performance of glass fibre/epoxy, carbon fibre/epoxy and Kevlar fibre/epoxy polymer composites. 3-point short beam shear tests were conducted on the conditioned specimens to evaluate the interfacial properties and failure modes which are related to mechanical properties of the composites. The effect of crosshead velocity (within the range 1-10 3 mm/min) on the interlaminar shear strength (ILSS) of all the three composite systems at different temperatures was studied. The glass transition temperature (T g ) of conditioned samples were measured by differential scanning calorimetry (DSC) in the temperature range of 25 °C to 150 °C temperature. At 1 mm/min loading rate, for both glass/epoxy and carbon/epoxy composites maximum increase in ILSS value was about 85.72% with respect to ambient, while for Kevlar/epoxy composite 31.77% reduction in ILSS was observed at -100 °C temperature

  7. Lower limb joint moment during walking in water.

    Science.gov (United States)

    Miyoshi, Tasuku; Shirota, Takashi; Yamamoto, Shin-Ichiro; Nakazawa, Kimitaka; Akai, Masami

    2003-11-04

    Walking in water is a widely used rehabilitation method for patients with orthopedic disorders or arthritis, based on the belief that the reduction of weight in water makes it a safer medium and prevents secondary injuries of the lower-limb joints. To our knowledge, however, no experimental data on lower-limb joint moment during walking in water is available. The aim of this study was to quantify the joint moments of the ankle, knee, and hip during walking in water in comparison with those on land. Eight healthy volunteers walked on land and in water at a speed comfortable for them. A video-motion analysis system and waterproof force platform were used to obtain kinematic data and to calculate the joint moments. The hip joint moment was shown to be an extension moment almost throughout the stance phase during walking in water, while it changed from an extension- to flexion-direction during walking on land. The knee joint moment had two extension peaks during walking on land, whereas it had only one extension peak, a late one, during walking in water. The ankle joint moment during walking in water was considerably reduced but in the same direction, plantarflexion, as that during walking on land. The joint moments of the hip, knee, and ankle were not merely reduced during walking in water; rather, inter-joint coordination was totally changed.

  8. Cardiovascular Responses Associated with Daily Walking in Subacute Stroke

    Directory of Open Access Journals (Sweden)

    Sanjay K. Prajapati

    2013-01-01

    Full Text Available Despite the importance of regaining independent ambulation after stroke, the amount of daily walking completed during in-patient rehabilitation is low. The purpose of this study is to determine if (1 walking-related heart rate responses reached the minimum intensity necessary for therapeutic aerobic exercise (40%–60% heart rate reserve or (2 heart rate responses during bouts of walking revealed excessive workload that may limit walking (>80% heart rate reserve. Eight individuals with subacute stroke attending in-patient rehabilitation were recruited. Participants wore heart rate monitors and accelerometers during a typical rehabilitation day. Walking-related changes in heart rate and walking bout duration were determined. Patients did not meet the minimum cumulative requirements of walking intensity (>40% heart rate reserve and duration (>10 minutes continuously necessary for cardiorespiratory benefit. Only one patient exceeded 80% heart rate reserve. The absence of significant increases in heart rate associated with walking reveals that patients chose to walk at speeds well below a level that has meaningful cardiorespiratory health benefits. Additionally, cardiorespiratory workload is unlikely to limit participation in walking. Measurement of heart rate and walking during in-patient rehabilitation may be a useful approach to encourage patients to increase the overall physical activity and to help facilitate recovery.

  9. Effects of Initial Stance of Quadruped Trotting on Walking Stability

    Directory of Open Access Journals (Sweden)

    Peisun Ma

    2008-11-01

    Full Text Available It is very important for quadruped walking machine to keep its stability in high speed walking. It has been indicated that moment around the supporting diagonal line of quadruped in trotting gait largely influences walking stability. In this paper, moment around the supporting diagonal line of quadruped in trotting gait is modeled and its effects on body attitude are analyzed. The degree of influence varies with different initial stances of quadruped and we get the optimal initial stance of quadruped in trotting gait with maximal walking stability. Simulation results are presented.

  10. Traffic Offences: Planned or Habitual? Using the Theory of Planned Behaviour and habit strength to explain frequency and magnitude of speeding and driving under the influence of alcohol.

    Science.gov (United States)

    Lheureux, Florent; Auzoult, Laurent; Charlois, Colette; Hardy-Massard, Sandrine; Minary, Jean-Pierre

    2016-02-01

    This study addresses the socio-cognitive determinants of traffic offences, in particular of speeding and drinking and driving. It has two aims: (1) to test the hypothesis of a direct effect of habits on offences (i.e., independent of intentions) by employing a specific measure of habits (i.e., the SRIH) and (2) to analyse the offences by taking account of three distinct parameters: Frequency, usual magnitude (i.e., the most frequent deviation from the law) and maximal magnitude (i.e., the greatest deviation occasionally adopted) in order to represent more accurately the variability of the offending behaviours. A total of 642 drivers replied to a questionnaire. The results corroborate the idea that intention and habit are distinct and direct determinants of offences. The use of the SRIH dismisses the criticisms made with regard to the measure of past behaviour. The distinction between the three behavioural parameters proves to be relevant, as their determinants are not exactly similar. Finally, attitude and subjective norm had direct effects on the maximal magnitude and/or on the frequency of the offence. The discussion concerns the contribution of this study to the analysis of offences as well as its limitations and addresses the theoretical plausibility of the direct effects of attitude and the subjective norm. © 2015 The British Psychological Society.

  11. Organic high ionic strength aqueous two-phase solvent system series for separation of ultra-polar compounds by spiral high-speed counter-current chromatography

    Science.gov (United States)

    Zeng, Yun; Liu, Gang; Ma, Ying; Chen, Xiaoyuan; Ito, Yoichiro

    2011-01-01

    Existing two-phase solvent systems for high-speed countercurrent chromatography cover the separation of hydrophobic to moderately polar compounds, but often fail to provide suitable partition coefficient values for highly polar compounds such as sulfonic acids, catecholamines and zwitter ions. The present paper introduces a new solvent series which can be applied for the separation of these polar compounds. It is composed of 1-butanol, ethanol, saturated ammonium sulfate and water at various volume ratios and consists of a series of 10 steps which are arranged according to the polarity of the solvent system so that the two-phase solvent system with suitable K values for the target compound(s) can be found in a few steps. Each solvent system gives proper volume ratio and high density difference between the two phases to provide a satisfactory level of retention of the stationary phase in the spiral column assembly. The method is validated by partition coefficient measurement of four typical polar compounds including methyl green (basic dye), tartrazine (sulfonic acid), tyrosine (zwitter ion) and epinephrine (a catecholamine), all of which show low partition coefficient values in the polar 1-butanol-water system. The capability of the method is demonstrated by separation of three catecholamines. PMID:22033108

  12. Treadmill training improves overground walking economy in Parkinson’s disease: A randomized, controlled pilot study

    Directory of Open Access Journals (Sweden)

    Miguel eFERNANDEZ-DEL-OLMO

    2014-09-01

    Full Text Available Gait disturbances are one of the principal and most incapacitating symptoms of Parkinson’s disease (PD. In addition, walking economy is impaired in PD patients and could contribute to excess fatigue in this population. An important number of studies have shown that treadmill training can improve kinematic parameters in PD patients. However, the effects of treadmill and overground walking on the walking economy remain unknown. The goal of this study was to explore the walking economy changes in response to a treadmill and an overground training program, as well as the differences in the walking economy during treadmill and overground walking. 22 mild PD patients were randomly assigned to a treadmill or overground training group. The training program consisted of 5 weeks (3 sessions/week. We evaluated the energy expenditure of overground walking, before and after each of the training programs. The energy expenditure of treadmill walking (before the program was also evaluated. The treadmill, but not the overground training program, lead to an improvement in the walking economy (the rate of oxygen consumed per distance, during overground walking at a preferred speed in PD patients. In addition, walking on a treadmill required more energy expenditure compared with overground walking at the same speed. This study provides evidence that in mild PD patients, treadmill training is more beneficial compared with that of walking overground, leading to a greater improvement in the walking economy. This finding is of clinical importance for the therapeutic administration of exercise in Parkinson’s disease.

  13. Association with isokinetic ankle strength measurements and normal clinical muscle testing in sciatica patients.

    Science.gov (United States)

    Ustun, N; Erol, O; Ozcakar, L; Ceceli, E; Ciner, O Akar; Yorgancioglu, Z R

    2013-01-01

    Sensitive muscle strength tests are needed to measure muscle strength in the diagnosis and management of sciatica patients. The aim of this study was to assess the isokinetic muscle strength in sciatica patients' and control subjects' ankles that exhibited normal ankle muscle strength when measured clinically. Forty-six patients with L5 and/or S1 nerve compression, and whose age, sex, weight, and height matched 36 healthy volunteers, were recruited to the study. Heel-walking, toe-walking, and manual muscle testing were used to perform ankle dorsiflexion and plantar flexion strengths in clinical examination. Patients with normal ankle dorsiflexion and plantar flexion strengths assessed by manual muscle testing and heel-and toe-walking tests were included in the study. Bilateral isokinetic (concentric/concentric) ankle plantar-flexion-dorsiflexion measurements of the patients and controls were performed within the protocol of 30°/sec (5 repetitions). Peak torque and peak torque/body weight were obtained for each ankle motion of the involved limb at 30°/s speed. L5 and/or S1 nerve compression was evident in 46 patients (76 injured limbs). Mean disease duration was two years. The plantar flexion muscle strength of the patients was found to be lower than that of the controls (p=0.036). The dorsiflexion muscle strength of the patients was found to be the same as that of the controls (p=0.211). Isokinetic testing is superior to clinical muscle testing when evaluating ankle plantar flexion torque in sciatica patients. Therefore, isokinetic muscle testing may be helpful when deciding whether to place a patient into a focused rehabilitation program.

  14. Aging well: Processing speed inhibition and working memory related to balance and aerobic endurance.

    Science.gov (United States)

    Zettel-Watson, Laura; Suen, Meagan; Wehbe, Lara; Rutledge, Dana N; Cherry, Barbara J

    2017-01-01

    The present study explored whether certain physical performance measures could be linked to specific cognitive domains in healthy older adults. A total of 50 adults (mean age 69.5 years, SD 8.1) were evaluated on physical performance using measures of balance (Fullerton Advanced Balance Scale), functional mobility (8-ft up-and-go), lower body strength (30-s chair stand), gait (30-ft walk velocity) and aerobic endurance (6-min walk). Cognitive measures included Stroop Color-Word Test, Digit Span Backward, Trail Making Tests, Everyday Problems Test, Digit Symbol Substitution and a Brown-Peterson test. Principal component analyses reduced cognition to domains of processing speed, inhibition and working memory. Hierarchical regression analyses were carried out with age and each physical measure as potential predictors of the three cognitive domains. The balance scale and 6-min walk were specifically associated with processing speed, inhibition and working memory. Better dynamic balance and aerobic endurance predicted enhanced processing speed, inhibition and working memory in older adults, with these last two domains considered components of executive function. Geriatr Gerontol Int 2017; 17: 108-115. © 2015 Japan Geriatrics Society.

  15. Running for exercise mitigates age-related deterioration of walking economy.

    Directory of Open Access Journals (Sweden)

    Justus D Ortega

    Full Text Available Impaired walking performance is a key predictor of morbidity among older adults. A distinctive characteristic of impaired walking performance among older adults is a greater metabolic cost (worse economy compared to young adults. However, older adults who consistently run have been shown to retain a similar running economy as young runners. Unfortunately, those running studies did not measure the metabolic cost of walking. Thus, it is unclear if running exercise can prevent the deterioration of walking economy.To determine if and how regular walking vs. running exercise affects the economy of locomotion in older adults.15 older adults (69 ± 3 years who walk ≥ 30 min, 3x/week for exercise, "walkers" and 15 older adults (69 ± 5 years who run ≥ 30 min, 3x/week, "runners" walked on a force-instrumented treadmill at three speeds (0.75, 1.25, and 1.75 m/s. We determined walking economy using expired gas analysis and walking mechanics via ground reaction forces during the last 2 minutes of each 5 minute trial. We compared walking economy between the two groups and to non-aerobically trained young and older adults from a prior study.Older runners had a 7-10% better walking economy than older walkers over the range of speeds tested (p = .016 and had walking economy similar to young sedentary adults over a similar range of speeds (p =  .237. We found no substantial biomechanical differences between older walkers and runners. In contrast to older runners, older walkers had similar walking economy as older sedentary adults (p =  .461 and ∼ 26% worse walking economy than young adults (p<.0001.Running mitigates the age-related deterioration of walking economy whereas walking for exercise appears to have minimal effect on the age-related deterioration in walking economy.

  16. Biomechanical implications of walking with indigenous footwear.

    Science.gov (United States)

    Willems, Catherine; Stassijns, Gaetane; Cornelis, Wim; D'Août, Kristiaan

    2017-04-01

    This study investigates biomechanical implications of walking with indigenous "Kolhapuri" footwear compared to barefoot walking among a population of South Indians. Ten healthy adults from South India walked barefoot and indigenously shod at voluntary speed on an artificial substrate. The experiment was repeated outside, on a natural substrate. Data were collected from (1) a heel-mounted 3D-accelerometer recording peak impact at heel contact, (2) an ankle-mounted 3D-goniometer (plantar/dorsiflexion and inversion/eversion), and (3) sEMG electrodes at the m. tibialis anterior and the m. gastrocnemius medialis. Data show that the effect of indigenous footwear on the measured variables, compared to barefoot walking, is relatively small and consistent between substrates (even though subjects walked faster on the natural substrate). Walking barefoot, compared to shod walking yields higher impact accelerations, but the differences are small and only significant for the artificial substrate. The main rotations of the ankle joint are mostly similar between conditions. Only the shod condition shows a faster ankle rotation over the rapid eversion motion on the natural substrate. Maximal dorsiflexion in late stance differs between the footwear conditions on an artificial substrate, with the shod condition involving a less dorsiflexed ankle, and the plantar flexion at toe-off is more extreme when shod. Overall the activity pattern of the external foot muscles is similar. The indigenous footwear studied (Kolhapuri) seems to alter foot biomechanics only in a subtle way. While offering some degree of protection, walking in this type of footwear resembles barefoot gait and this type of indigenous footwear might be considered "minimal". © 2017 The Authors American Journal of Physical Anthropology Published by Wiley Periodicals, Inc.

  17. Comparative analysis of speed's impact on muscle demands during partial body weight support motor-assisted elliptical training.

    Science.gov (United States)

    Burnfield, Judith M; Irons, Sonya L; Buster, Thad W; Taylor, Adam P; Hildner, Gretchen A; Shu, Yu

    2014-01-01

    Individuals with walking limitations often experience challenges engaging in functionally relevant exercise. An adapted elliptical trainer (motor to assist pedal movement, integrated body weight harness, ramps/stairs, and grab rails) has been developed to help individuals with physical disabilities and chronic conditions regain/retain walking capacity and fitness. However, limited published studies are available to guide therapeutic interventions. This repeated measures study examined the influence of motor-assisted elliptical training speed on lower extremity muscle demands at four body weight support (BWS) levels commonly used therapeutically for walking. Electromyography (EMG) and pedal trajectory data were recorded as ten individuals without known disability used the motor-assisted elliptical trainer at three speeds [20,40, 60 revolutions per minute (RPM)] during each BWS level (0%, 20%, 40%, 60%). Overall, the EMG activity (peak, mean, duration) in key stabilizer muscles (i.e., gluteus medius, gluteus maximus, vastus lateralis, medial gastrocnemius and soleus) recorded at 60 RPM exceeded those at 40 RPM, which were higher than values at 20 RPM in all but three situations (gluteus medius mean at 0% BWS, vastus lateralis mean at 20% BWS, soleus duration at 40% BWS); however, these differences did not always achieve statistical significance. Slower motor-assisted speeds can be used to accommodate weakness of gluteus medius, gluteus maximus, vastus lateralis, medial gastrocnemius and soleus. As strength improves, training at faster motor-assisted speeds may provide a means to progressively challenge key lower extremity stabilizers. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Women with fibromyalgia walk with an altered muscle synergy.

    Science.gov (United States)

    Pierrynowski, Michael R; Tiidus, Peter M; Galea, Victoria

    2005-11-01

    Most individuals can use different movement and muscle recruitment patterns to perform a stated task but often only one pattern is selected which optimizes an unknown global objective given the individual's neuromusculoskeletal characteristics. Patients with fibromyalgia syndrome (FS), characterized by their chronic pain, reduced physical work capacity and muscular fatigue, could exhibit a different control signature compared to asymptomatic control volunteers (CV). To test this proposal, 22 women with FS, and 11 CV, were assessed in a gait analysis laboratory. Each subject walked repeatedly at self-selected slow, comfortable, and fast walking speeds. The gait analysis provided, for each walk, each subject's stride time, length, and velocity, and ground reaction force, and lower extremity joint kinematics, moments and powers. The data were then anthropometrically scaled and velocity normalized to reduce the influence of subject mass, leg length, and walking speed on the measured gait outcomes. Similarities and differences in the two groups' scaled and normalized gait patterns were then determined. Results show that FS and CV walk with externally similar stride lengths, times, and velocities, and joint angles and ground reaction forces but they use internally different muscle recruitment patterns. Specifically, FS preferentially power gait using their hip flexors instead of their ankle plantarflexors. Interestingly, CV use a similar muscle fatiguing recruitment pattern to walk fast which parallels the common complaint of fatigue reported by FS walking at comfortable speed.

  19. High on walking

    DEFF Research Database (Denmark)

    Woythal, Bente Martinsen; Haahr, Anita; Dreyer, Pia

    2018-01-01

    a leg, and people who live with Parkinson’s disease. The analysis of the data is inspired by Paul Ricoeur’s philosophy of interpretation. Four themes were identified: (a) I feel high in two ways; (b) Walking has to be automatic; (c) Every Monday, I walk with the girls in the park; and (d) I dream...

  20. James Watt's Leicester Walk

    OpenAIRE

    Bell, Kathleen

    2016-01-01

    a poem in which James Watt, inventor of the separate condenser, walks through contemporary Leicester (his route is from Bonners Lane and alongside the canal, taking in the Statue of Liberty on its traffic island near Sage Road). It is derived from the exercise of taking a character for a walk,

  1. More Adults Are Walking

    Centers for Disease Control (CDC) Podcasts

    2012-07-31

    This podcast is based on the August 2012 CDC Vital Signs report. While more adults are walking, only half get the recommended amount of physical activity. Listen to learn how communities, employers, and individuals may help increase walking.  Created: 7/31/2012 by Centers for Disease Control and Prevention (CDC).   Date Released: 8/7/2012.

  2. Lévy walks

    Science.gov (United States)

    Zaburdaev, V.; Denisov, S.; Klafter, J.

    2015-04-01

    Random walk is a fundamental concept with applications ranging from quantum physics to econometrics. Remarkably, one specific model of random walks appears to be ubiquitous across many fields as a tool to analyze transport phenomena in which the dispersal process is faster than dictated by Brownian diffusion. The Lévy-walk model combines two key features, the ability to generate anomalously fast diffusion and a finite velocity of a random walker. Recent results in optics, Hamiltonian chaos, cold atom dynamics, biophysics, and behavioral science demonstrate that this particular type of random walk provides significant insight into complex transport phenomena. This review gives a self-consistent introduction to Lévy walks, surveys their existing applications, including latest advances, and outlines further perspectives.

  3. Neuromorphic walking gait control.

    Science.gov (United States)

    Still, Susanne; Hepp, Klaus; Douglas, Rodney J

    2006-03-01

    We present a neuromorphic pattern generator for controlling the walking gaits of four-legged robots which is inspired by central pattern generators found in the nervous system and which is implemented as a very large scale integrated (VLSI) chip. The chip contains oscillator circuits that mimic the output of motor neurons in a strongly simplified way. We show that four coupled oscillators can produce rhythmic patterns with phase relationships that are appropriate to generate all four-legged animal walking gaits. These phase relationships together with frequency and duty cycle of the oscillators determine the walking behavior of a robot driven by the chip, and they depend on a small set of stationary bias voltages. We give analytic expressions for these dependencies. This chip reduces the complex, dynamic inter-leg control problem associated with walking gait generation to the problem of setting a few stationary parameters. It provides a compact and low power solution for walking gait control in robots.

  4. Running for exercise mitigates age-related deterioration of walking economy.

    Science.gov (United States)

    Ortega, Justus D; Beck, Owen N; Roby, Jaclyn M; Turney, Aria L; Kram, Rodger

    2014-01-01

    Impaired walking performance is a key predictor of morbidity among older adults. A distinctive characteristic of impaired walking performance among older adults is a greater metabolic cost (worse economy) compared to young adults. However, older adults who consistently run have been shown to retain a similar running economy as young runners. Unfortunately, those running studies did not measure the metabolic cost of walking. Thus, it is unclear if running exercise can prevent the deterioration of walking economy. To determine if and how regular walking vs. running exercise affects the economy of locomotion in older adults. 15 older adults (69 ± 3 years) who walk ≥ 30 min, 3x/week for exercise, "walkers" and 15 older adults (69 ± 5 years) who run ≥ 30 min, 3x/week, "runners" walked on a force-instrumented treadmill at three speeds (0.75, 1.25, and 1.75 m/s). We determined walking economy using expired gas analysis and walking mechanics via ground reaction forces during the last 2 minutes of each 5 minute trial. We compared walking economy between the two groups and to non-aerobically trained young and older adults from a prior study. Older runners had a 7-10% better walking economy than older walkers over the range of speeds tested (p = .016) and had walking economy similar to young sedentary adults over a similar range of speeds (p =  .237). We found no substantial biomechanical differences between older walkers and runners. In contrast to older runners, older walkers had similar walking economy as older sedentary adults (p =  .461) and ∼ 26% worse walking economy than young adults (peconomy whereas walking for exercise appears to have minimal effect on the age-related deterioration in walking economy.

  5. Biomechanical analysis of rollator walking

    DEFF Research Database (Denmark)

    Alkjaer, T; Larsen, Peter K; Pedersen, Gitte

    2006-01-01

    The rollator is a very popular walking aid. However, knowledge about how a rollator affects the walking patterns is limited. Thus, the purpose of the study was to investigate the biomechanical effects of walking with and without a rollator on the walking pattern in healthy subjects.......The rollator is a very popular walking aid. However, knowledge about how a rollator affects the walking patterns is limited. Thus, the purpose of the study was to investigate the biomechanical effects of walking with and without a rollator on the walking pattern in healthy subjects....

  6. Dynamic optimization of a biped model: Energetic walking gaits with different mechanical and gait parameters

    Directory of Open Access Journals (Sweden)

    Kang An

    2015-05-01

    Full Text Available Energy consumption is one of the problems for bipedal robots walking. For the purpose of studying the parameter effects on the design of energetic walking bipeds with strong adaptability, we use a dynamic optimization method on our new walking model to first investigate the effects of the mechanical parameters, including mass and length distribution, on the walking efficiency. Then, we study the energetic walking gait features with the combinations of walking speed and step length. Our walking model is designed upon Srinivasan’s model. Dynamic optimization is used for a free search with minimal constraints. The results show that the cost of transport of a certain gait increases with the increase in the mass and length distribution parameters, except for that the cost of transport decreases with big length distribution parameter and long step length. We can also find a corresponding range of walking speed and step length, in which the variation in one of the two parameters has no obvious effect on the cost of transport. With fixed mechanical parameters, the cost of transport increases with the increase in the walking speed. There is a speed–step length relationship for walking with minimal cost of transport. The hip torque output strategy is adjusted in two situations to meet the walking requirements.

  7. Alzheimer random walk

    Science.gov (United States)

    Odagaki, Takashi; Kasuya, Keisuke

    2017-09-01

    Using the Monte Carlo simulation, we investigate a memory-impaired self-avoiding walk on a square lattice in which a random walker marks each of sites visited with a given probability p and makes a random walk avoiding the marked sites. Namely, p = 0 and p = 1 correspond to the simple random walk and the self-avoiding walk, respectively. When p> 0, there is a finite probability that the walker is trapped. We show that the trap time distribution can well be fitted by Stacy's Weibull distribution b(a/b){a+1}/{b}[Γ({a+1}/{b})]-1x^a\\exp(-a/bx^b)} where a and b are fitting parameters depending on p. We also find that the mean trap time diverges at p = 0 as p- α with α = 1.89. In order to produce sufficient number of long walks, we exploit the pivot algorithm and obtain the mean square displacement and its Flory exponent ν(p) as functions of p. We find that the exponent determined for 1000 step walks interpolates both limits ν(0) for the simple random walk and ν(1) for the self-avoiding walk as [ ν(p) - ν(0) ] / [ ν(1) - ν(0) ] = pβ with β = 0.388 when p ≪ 0.1 and β = 0.0822 when p ≫ 0.1. Contribution to the Topical Issue "Continuous Time Random Walk Still Trendy: Fifty-year History, Current State and Outlook", edited by Ryszard Kutner and Jaume Masoliver.

  8. Variability in energy cost and walking gait during race walking in competitive race walkers.

    Science.gov (United States)

    Brisswalter, J; Fougeron, B; Legros, P

    1998-09-01

    The aim of this study was to examine the variability of energy cost (Cw) and race walking gait after a 3-h walk at the competition pace in race walkers of the same performance level. Nine competitive race walkers were studied. In the same week, after a first test of VO2max determination, each subject completed two submaximal treadmill walks (6 min length, 0% grade, 12 km X h(-1) speed) before and after a 3-h overground test completed at the individual competition speed of the race walker. During the two submaximal tests, subjects were filmed between the 2nd and the 4th min, and physiological parameters were recorded between the 4th and the 6th min. Results showed two trends. On the one hand, we observed a significant and systematic increase in energy cost of walking (mean deltaCw = 8.4%), whereas no variation in the gait kinematics prescribed by the rules of race walking was recorded. On the other hand, this increase in metabolic energy demand was accompanied by variations of different magnitude and direction of stride length, of the excursion of the heel and of the maximal ankle flexion at toe-off among the race walkers. These results indicated that competitive race walkers are able to maintain their walking gait with exercise duration apart from a systematic increase in energy cost. Moreover, in this form of locomotion the effect of fatigue on the gait variability seems to be an individual function of the race walk constraints and the constraints of the performer.

  9. Random walk centrality for temporal networks

    International Nuclear Information System (INIS)

    Rocha, Luis E C; Masuda, Naoki

    2014-01-01

    Nodes can be ranked according to their relative importance within a network. Ranking algorithms based on random walks are particularly useful because they connect topological and diffusive properties of the network. Previous methods based on random walks, for example the PageRank, have focused on static structures. However, several realistic networks are indeed dynamic, meaning that their structure changes in time. In this paper, we propose a centrality measure for temporal networks based on random walks under periodic boundary conditions that we call TempoRank. It is known that, in static networks, the stationary density of the random walk is proportional to the degree or the strength of a node. In contrast, we find that, in temporal networks, the stationary density is proportional to the in-strength of the so-called effective network, a weighted and directed network explicitly constructed from the original sequence of transition matrices. The stationary density also depends on the sojourn probability q, which regulates the tendency of the walker to stay in the node, and on the temporal resolution of the data. We apply our method to human interaction networks and show that although it is important for a node to be connected to another node with many random walkers (one of the principles of the PageRank) at the right moment, this effect is negligible in practice when the time order of link activation is included. (paper)

  10. Random walk centrality for temporal networks

    Science.gov (United States)

    Rocha, Luis E. C.; Masuda, Naoki

    2014-06-01

    Nodes can be ranked according to their relative importance within a network. Ranking algorithms based on random walks are particularly useful because they connect topological and diffusive properties of the network. Previous methods based on random walks, for example the PageRank, have focused on static structures. However, several realistic networks are indeed dynamic, meaning that their structure changes in time. In this paper, we propose a centrality measure for temporal networks based on random walks under periodic boundary conditions that we call TempoRank. It is known that, in static networks, the stationary density of the random walk is proportional to the degree or the strength of a node. In contrast, we find that, in temporal networks, the stationary density is proportional to the in-strength of the so-called effective network, a weighted and directed network explicitly constructed from the original sequence of transition matrices. The stationary density also depends on the sojourn probability q, which regulates the tendency of the walker to stay in the node, and on the temporal resolution of the data. We apply our method to human interaction networks and show that although it is important for a node to be connected to another node with many random walkers (one of the principles of the PageRank) at the right moment, this effect is negligible in practice when the time order of link activation is included.

  11. Cardiorespiratory Responses to Pool Floor Walking in People Poststroke.

    Science.gov (United States)

    Jeng, Brenda; Fujii, Takuto; Lim, Hyosok; Vrongistinos, Konstantinos; Jung, Taeyou

    2018-03-01

    To compare cardiorespiratory responses between pool floor walking and overground walking (OW) in people poststroke. Cross-sectional study. University-based therapeutic exercise facility. Participants (N=28) were comprised of 14 community-dwelling individuals poststroke (5.57±3.57y poststroke) and 14 age- and sex-matched healthy adults (mean age, 58.00±15.51y; male/female ratio, 9:5). Not applicable. A telemetric metabolic system was used to collect cardiorespiratory variables, including oxygen consumption (V˙o 2 ), energy expenditure (EE), and expired volume per unit time (V˙e), during 6-minute walking sessions in chest-depth water and on land at a matched speed, determined by average of maximum walking speed in water. Individuals poststroke elicited no significant differences in cardiorespiratory responses between pool floor walking and OW. However, healthy controls showed significant increases in mean V˙o 2 values by 94%, EE values by 109%, and V˙e values by 94% (all Pstroke group did not. Our results indicate that people poststroke, unlike healthy adults, do not increase EE while walking in water compared with on land. Unlike stationary walking on an aquatic treadmill, forward locomotion during pool floor walking at faster speeds may have increased drag force, which requires greater EE from healthy adults. Without demanding excessive EE, walking in water may offer a naturally supportive environment for gait training in the early stages of rehabilitation. Copyright © 2017 American Congress of Rehabilitation Medicine. All rights reserved.

  12. Spatial search by quantum walk

    International Nuclear Information System (INIS)

    Childs, Andrew M.; Goldstone, Jeffrey

    2004-01-01

    Grover's quantum search algorithm provides a way to speed up combinatorial search, but is not directly applicable to searching a physical database. Nevertheless, Aaronson and Ambainis showed that a database of N items laid out in d spatial dimensions can be searched in time of order √(N) for d>2, and in time of order √(N) poly(log N) for d=2. We consider an alternative search algorithm based on a continuous-time quantum walk on a graph. The case of the complete graph gives the continuous-time search algorithm of Farhi and Gutmann, and other previously known results can be used to show that √(N) speedup can also be achieved on the hypercube. We show that full √(N) speedup can be achieved on a d-dimensional periodic lattice for d>4. In d=4, the quantum walk search algorithm takes time of order √(N) poly(log N), and in d<4, the algorithm does not provide substantial speedup

  13. Which walking capacity tests to use in multiple sclerosis? A multicentre study providing the basis for a core set

    NARCIS (Netherlands)

    Gijbels, D.; Dalgas, U.; Romberg, A.; de Groot, V.; Bethoux, F.; Vaney, C.; Gebara, B.; Santoyo, C.; Maamagi, H.; Rasova, K.; de Maertens, N.B.; Knuts, K.; Feys, P.

    2012-01-01

    Background: Many different walking capacity test formats are being used. It is unclear whether walking speed, obtained from short tests, and walking distance, obtained from long tests, provide different clinical information. Objectives: To determine the differential effect of various short and long

  14. The Act of Walking

    DEFF Research Database (Denmark)

    Vestergaard, Maria Quvang Harck; Olesen, Mette; Helmer, Pernille Falborg

    2014-01-01

    ’ of mobility (Jensen 2013:111) such as the urban environment, and the infrastructures. Walking has indeed also a ‘software dimension’ as an embodied performance that trigger the human senses (Jensen 2013) and which is closely related to the habitus and identity of the individual (Halprin 1963). The individual......The ability to walk in an area is, in the existing literature, often explained by the physical structures like building density and the presence of facilities in an area, and it is often termed ‘walkability’ (Patton 2007; Forsyth and Southworth 2008; Krizek, Handy and Forsyth 2009; Johnson 2003......; Frumkin 2002). The term ‘walkability’ focuses on how the physical structures in the urban environment can promote walking, and how this potentially eases issues of public health and liveability in our cities (Krizek et al. 2009). However, the study of walking should not be reduced merely to the ‘hardware...

  15. Minimal Walking Technicolor

    DEFF Research Database (Denmark)

    Foadi, Roshan; Frandsen, Mads Toudal; A. Ryttov, T.

    2007-01-01

    Different theoretical and phenomenological aspects of the Minimal and Nonminimal Walking Technicolor theories have recently been studied. The goal here is to make the models ready for collider phenomenology. We do this by constructing the low energy effective theory containing scalars......, pseudoscalars, vector mesons and other fields predicted by the minimal walking theory. We construct their self-interactions and interactions with standard model fields. Using the Weinberg sum rules, opportunely modified to take into account the walking behavior of the underlying gauge theory, we find...... interesting relations for the spin-one spectrum. We derive the electroweak parameters using the newly constructed effective theory and compare the results with the underlying gauge theory. Our analysis is sufficiently general such that the resulting model can be used to represent a generic walking technicolor...

  16. Walking - Sensing - Participation

    DEFF Research Database (Denmark)

    Bødker, Mads; Meinhardt, Nina Dam; Browning, David

    2014-01-01

    Building on ethnographic research and social theory in the field of ‘mobilities’, this workshop paper suggests that field work based on simply walking with people entails a form of embodied participation that informs technological interventions by creating a space within which to address a wider ...... set of experiential or ‘felt’ qualities of living with mobile technologies. Moving from reflections on the value of walking with people, the paper outlines some affordances of a smartphone application built to capture place experiences through walking.......Building on ethnographic research and social theory in the field of ‘mobilities’, this workshop paper suggests that field work based on simply walking with people entails a form of embodied participation that informs technological interventions by creating a space within which to address a wider...

  17. What Is Walking Pneumonia?

    Science.gov (United States)

    ... different from regular pneumonia? Answers from Eric J. Olson, M.D. Walking pneumonia is an informal term ... be treated with an antibiotic. With Eric J. Olson, M.D. Goldman L, et al., eds. Mycoplasma ...

  18. walk over ℤ

    Directory of Open Access Journals (Sweden)

    Philippe Leroux

    2005-01-01

    walk over ℤ can be described from a coassociative coalgebra. Relationships between this coalgebra and the set of periodic orbits of the classical chaotic system x↦2x mod⁡1, x∈[0,1], are also given.

  19. Two Legged Walking Robot

    OpenAIRE

    Kraus, V.

    2015-01-01

    The aim of this work is to construct a two-legged wirelessly controlled walking robot. This paper describes the construction of the robot, its control electronics, and the solution of the wireless control. The article also includes a description of the application to control the robot. The control electronics of the walking robot are built using the development kit Arduino Mega, which is enhanced with WiFi module allowing the wireless control, a set of ultrasonic sensors for detecting obstacl...

  20. Foot trajectory approximation using the pendulum model of walking.

    Science.gov (United States)

    Fang, Juan; Vuckovic, Aleksandra; Galen, Sujay; Conway, Bernard A; Hunt, Kenneth J

    2014-01-01

    Generating a natural foot trajectory is an important objective in robotic systems for rehabilitation of walking. Human walking has pendular properties, so the pendulum model of walking has been used in bipedal robots which produce rhythmic gait patterns. Whether natural foot trajectories can be produced by the pendulum model needs to be addressed as a first step towards applying the pendulum concept in gait orthosis design. This study investigated circle approximation of the foot trajectories, with focus on the geometry of the pendulum model of walking. Three able-bodied subjects walked overground at various speeds, and foot trajectories relative to the hip were analysed. Four circle approximation approaches were developed, and best-fit circle algorithms were derived to fit the trajectories of the ankle, heel and toe. The study confirmed that the ankle and heel trajectories during stance and the toe trajectory in both the stance and the swing phases during walking at various speeds could be well modelled by a rigid pendulum. All the pendulum models were centred around the hip with pendular lengths approximately equal to the segment distances from the hip. This observation provides a new approach for using the pendulum model of walking in gait orthosis design.

  1. The effect of impedance-controlled robotic gait training on walking ability and quality in individuals with chronic incomplete spinal cord injury: an explorative study.

    Science.gov (United States)

    Fleerkotte, Bertine M; Koopman, Bram; Buurke, Jaap H; van Asseldonk, Edwin H F; van der Kooij, Herman; Rietman, Johan S

    2014-03-04

    rehabilitation of chronic iSCI individuals. It leads to improvements in walking ability, muscle strength, and quality of walking. Improvements observed at the end of the training period persisted at the eight-week follow-up. Slower walkers benefit the most from the training protocol and achieve the greatest relative improvement in speed and walking distance.

  2. The Influence of Radiographic Severity on the Relationship between Muscle Strength and Joint Loading in Obese Knee Osteoarthritis Patients

    Directory of Open Access Journals (Sweden)

    Jens Aaboe

    2011-01-01

    Full Text Available Objective. To investigate the relationship between knee muscle strength and the external knee adduction moment during walking in obese knee osteoarthritis patients and whether disease severity influences this relationship. Methods. This cross-sectional study included 136 elderly obese (BMI>30 adults with predominant medial knee osteoarthritis. Muscle strength, standing radiographic severity as measured by the Kellgren and Lawrence scale, and the peak external knee adduction moment were measured at self-selected walking speed. Results. According to radiographic severity, patients were classified as “less severe” (KL 1-2, N=73 or “severe” (KL 3-4, N=63. A significant positive association was demonstrated between the peak knee adduction moment and hamstring muscle strength in the whole cohort (P=.047. However, disease severity did not influence the relationship between muscle strength and dynamic medial knee joint loading. Severe patients had higher peak knee adduction moment and more varus malalignment (P<.001. Conclusion. Higher hamstring muscle strength relates to higher estimates of dynamic knee joint loading in the medial compartment. No such relationship existed for quadriceps muscle strength. Although cross sectional, the results suggest that hamstrings function should receive increased attention in future studies and treatments that aim at halting disease progression.

  3. Walking the Everyday

    Directory of Open Access Journals (Sweden)

    Matthew Bissen

    2014-11-01

    Full Text Available Since 2010, @matthewalking (Bissen, 2013 has published real-time public texts of walks in the city. This text-based Twitter feed has developed a narrative of a particular everyday life and developed a space of interface with others that represents a centering of perspective within an urban landscape. Walking the city provides a spatial, tactile, social, and embodied knowledge of the environment as each of us emerges into a space, orients ourselves, and determines a path that is highly localized, but is in connection with distant spaces and cultures. According to Ben Jacks in “Walking the City: Manhattan Projects,” “for urban dwellers and designers, walking is a fundamental tool for laying claim to, understanding, and shaping a livable city. Walking yields bodily knowing, recovers place memory, creates narrative, prioritizes human scale, and reconnects people to places” (75. @matthewalking’s walks, at times for as long as 5 hours, attempt to center an experience of an urban existence in a spatial narrative of the city that at once prioritizes a connection to place, but also is projected outward into a mediated relationship with others. The project is a series of unbounded walks, or dérives (drift, through the city that are logged on Twitter and traced to create an archive map of a set of particular urban experiences. The dérive concept as outlined in “The Theory of the Dérive,” by Guy Debord is when “one or more persons during a certain period drop their relations, their work and leisure activities, and all their other usual motives for movement and action, and let themselves be drawn by the attractions of the terrain and the encounters they find there” (62.

  4. Patient Satisfaction of Using the ActiGait® Drop Foot Stimulator System and Effect of Treatment on Walking

    DEFF Research Database (Denmark)

    Severinsen, Kåre Eg; Grey, Kurt; Juhl, Anne

    2014-01-01

    In this case-control study of ten chronic stroke patients with drop foot we report preliminary data on patient satisfaction, self- assessed changes in walking performance, effect on walking speed as well as adverse effects after surgical implantation of the ActiGait® drop foot stimulator in a cli...... with great care due to the small population size, the case control design and the limitations of the ten meter walk test in describing walking quality and safety....

  5. Inverse association between insulin resistance and gait speed in nondiabetic older men: results from the U.S. National Health and Nutrition Examination Survey (NHANES 1999-2002

    Directory of Open Access Journals (Sweden)

    Yu Yau-Hua

    2009-11-01

    Full Text Available Abstract Background Recent studies have revealed the associations between insulin resistance (IR and geriatric conditions such as frailty and cognitive impairment. However, little is known about the relation of IR to physical impairment and limitation in the aging process, eg. slow gait speed and poor muscle strength. The aim of this study is to determine the effect of IR in performance-based physical function, specifically gait speed and leg strength, among nondiabetic older adults. Methods Cross-sectional data were from the population-based National Health and Nutrition Examination Survey (1999-2002. A total of 1168 nondiabetic adults (≥ 50 years with nonmissing values in fasting measures of insulin and glucose, habitual gait speed (HGS, and leg strength were analyzed. IR was assessed by homeostasis model assessment (HOMA-IR, whereas HGS and peak leg strength by the 20-foot timed walk test and an isokinetic dynamometer, respectively. We used multiple linear regression to examine the association between IR and performance-based physical function. Results IR was inversely associated with gait speed among the men. After adjusting demographics, body mass index, alcohol consumption, smoking status, chronic co-morbidities, and markers of nutrition and cardiovascular risk, each increment of 1 standard deviation in the HOMA-IR level was associated with a 0.04 m/sec decrease (p = 0.003 in the HGS in men. We did not find such association among the women. The IR-HGS association was not changed after further adjustment of leg strength. Last, HOMA-IR was not demonstrated in association with peak leg strength. Conclusion IR is inversely associated with HGS among older men without diabetes. The results suggest that IR, an important indicator of gait function among men, could be further investigated as an intervenable target to prevent walking limitation.

  6. Frontal joint dynamics when initiating stair ascent from a walk versus a stand.

    Science.gov (United States)

    Vallabhajosula, Srikant; Yentes, Jennifer M; Stergiou, Nicholas

    2012-02-02

    Ascending stairs is a challenging activity of daily living for many populations. Frontal plane joint dynamics are critical to understand the mechanisms involved in stair ascension as they contribute to both propulsion and medio-lateral stability. However, previous research is limited to understanding these dynamics while initiating stair ascent from a stand. We investigated if initiating stair ascent from a walk with a comfortable self-selected speed could affect the frontal plane lower-extremity joint moments and powers as compared to initiating stair ascent from a stand and if this difference would exist at consecutive ipsilateral steps on the stairs. Kinematics data using a 3-D motion capture system and kinetics data using two force platforms on the first and third stair treads were recorded simultaneously as ten healthy young adults ascended a custom-built staircase. Data were collected from two starting conditions of stair ascent, from a walk (speed: 1.42 ± 0.21 m/s) and from a stand. Results showed that subjects generated greater peak knee abductor moment and greater peak hip abductor moment when initiating stair ascent from a walk. Greater peak joint moments and powers at all joints were also seen while ascending the second ipsilateral step. Particularly, greater peak hip abductor moment was needed to avoid contact of the contralateral limb with the intermediate step by counteracting the pelvic drop on the contralateral side. This could be important for therapists using stair climbing as a testing/training tool to evaluate hip strength in individuals with documented frontal plane abnormalities (i.e. knee and hip osteoarthritis, ACL injury). Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Human Leg Model Predicts Muscle Forces, States, and Energetics during Walking.

    Science.gov (United States)

    Markowitz, Jared; Herr, Hugh

    2016-05-01

    Humans employ a high degree of redundancy in joint actuation, with different combinations of muscle and tendon action providing the same net joint torque. Both the resolution of these redundancies and the energetics of such systems depend on the dynamic properties of muscles and tendons, particularly their force-length relations. Current walking models that use stock parameters when simulating muscle-tendon dynamics tend to significantly overestimate metabolic consumption, perhaps because they do not adequately consider the role of elasticity. As an alternative, we posit that the muscle-tendon morphology of the human leg has evolved to maximize the metabolic efficiency of walking at self-selected speed. We use a data-driven approach to evaluate this hypothesis, utilizing kinematic, kinetic, electromyographic (EMG), and metabolic data taken from five participants walking at self-selected speed. The kinematic and kinetic data are used to estimate muscle-tendon lengths, muscle moment arms, and joint moments while the EMG data are used to estimate muscle activations. For each subject we perform an optimization using prescribed skeletal kinematics, varying the parameters that govern the force-length curve of each tendon as well as the strength and optimal fiber length of each muscle while seeking to simultaneously minimize metabolic cost and maximize agreement with the estimated joint moments. We find that the metabolic cost of transport (MCOT) values of our participants may be correctly matched (on average 0.36±0.02 predicted, 0.35±0.02 measured) with acceptable joint torque fidelity through application of a single constraint to the muscle metabolic budget. The associated optimal muscle-tendon parameter sets allow us to estimate the forces and states of individual muscles, resolving redundancies in joint actuation and lending insight into the potential roles and control objectives of the muscles of the leg throughout the gait cycle.

  8. Human Leg Model Predicts Muscle Forces, States, and Energetics during Walking.

    Directory of Open Access Journals (Sweden)

    Jared Markowitz

    2016-05-01

    Full Text Available Humans employ a high degree of redundancy in joint actuation, with different combinations of muscle and tendon action providing the same net joint torque. Both the resolution of these redundancies and the energetics of such systems depend on the dynamic properties of muscles and tendons, particularly their force-length relations. Current walking models that use stock parameters when simulating muscle-tendon dynamics tend to significantly overestimate metabolic consumption, perhaps because they do not adequately consider the role of elasticity. As an alternative, we posit that the muscle-tendon morphology of the human leg has evolved to maximize the metabolic efficiency of walking at self-selected speed. We use a data-driven approach to evaluate this hypothesis, utilizing kinematic, kinetic, electromyographic (EMG, and metabolic data taken from five participants walking at self-selected speed. The kinematic and kinetic data are used to estimate muscle-tendon lengths, muscle moment arms, and joint moments while the EMG data are used to estimate muscle activations. For each subject we perform an optimization using prescribed skeletal kinematics, varying the parameters that govern the force-length curve of each tendon as well as the strength and optimal fiber length of each muscle while seeking to simultaneously minimize metabolic cost and maximize agreement with the estimated joint moments. We find that the metabolic cost of transport (MCOT values of our participants may be correctly matched (on average 0.36±0.02 predicted, 0.35±0.02 measured with acceptable joint torque fidelity through application of a single constraint to the muscle metabolic budget. The associated optimal muscle-tendon parameter sets allow us to estimate the forces and states of individual muscles, resolving redundancies in joint actuation and lending insight into the potential roles and control objectives of the muscles of the leg throughout the gait cycle.

  9. Using dynamic walking models to identify factors that contribute to increased risk of falling in older adults.

    Science.gov (United States)

    Roos, Paulien E; Dingwell, Jonathan B

    2013-10-01

    Falls are common in older adults. The most common cause of falls is tripping while walking. Simulation studies demonstrated that older adults may be restricted by lower limb strength and movement speed to regain balance after a trip. This review examines how modeling approaches can be used to determine how different measures predict actual fall risk and what some of the causal mechanisms of fall risk are. Although increased gait variability predicts increased fall risk experimentally, it is not clear which variability measures could best be used, or what magnitude of change corresponded with increased fall risk. With a simulation study we showed that the increase in fall risk with a certain increase in gait variability was greatly influenced by the initial level of variability. Gait variability can therefore not easily be used to predict fall risk. We therefore explored other measures that may be related to fall risk and investigated the relationship between stability measures such as Floquet multipliers and local divergence exponents and actual fall risk in a dynamic walking model. We demonstrated that short-term local divergence exponents were a good early predictor for fall risk. Neuronal noise increases with age. It has however not been fully understood if increased neuronal noise would cause an increased fall risk. With our dynamic walking model we showed that increased neuronal noise caused increased fall risk. Although people who are at increased risk of falling reduce their walking speed it had been questioned whether this slower speed would actually cause a reduced fall risk. With our model we demonstrated that a reduced walking speed caused a reduction in fall risk. This may be due to the decreased kinematic variability as a result of the reduced signal-dependent noise of the smaller muscle forces that are required for slower. These insights may be used in the development of fall prevention programs in order to better identify those at increased risk of

  10. Using Dynamic Walking Models to Identify Factors that Contribute to Increased Risk of Falling in Older Adults

    Science.gov (United States)

    Roos, Paulien E.; Dingwell, Jonathan B.

    2013-01-01

    Falls are common in older adults. The most common cause of falls is tripping while walking. Simulation studies demonstrated that older adults may be restricted by lower limb strength and movement speed to regain balance after a trip. This review examines how modeling approaches can be used to determine how different measures predict actual fall risk and what some of the causal mechanisms of fall risk are. Although increased gait variability predicts increased fall risk experimentally, it is not clear which variability measures could best be used, or what magnitude of change corresponded with increased fall risk. With a simulation study we showed that the increase in fall risk with a certain increase in gait variability was greatly influenced by the initial level of variability. Gait variability can therefore not easily be used to predict fall risk. We therefore explored other measures that may be related to fall risk and investigated the relationship between stability measures such as Floquet multipliers and local divergence exponents and actual fall risk in a dynamic walking model. We demonstrated that short-term local divergence exponents were a good early predictor for fall risk. Neuronal noise increases with age. It has however not been fully understood if increased neuronal noise would cause an increased fall risk. With our dynamic walking model we showed that increased neuronal noise caused increased fall risk. Although people who are at increased risk of falling reduce their walking speed it had been questioned whether this slower speed would actually cause a reduced fall risk. With our model we demonstrated that a reduced walking speed caused a reduction in fall risk. This may be due to the decreased kinematic variability as a result of the reduced signal-dependent noise of the smaller muscle forces that are required for slower. These insights may be used in the development of fall prevention programs in order to better identify those at increased risk of

  11. Physiotherapy Effects in Gait Speed in Patients with Knee Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Klejda Tani

    2018-03-01

    CONCLUSIONS: Our results indicated that there was a significant decrease in pain and increase of gait speed while walking for 10 meters. Kinesio Tape can be used in patients with knee osteoarthritis, especially when changing walking stereotypes is a long-term goal of the treatment.

  12. Changes in executive functions and self-efficacy are independently associated with improved usual gait speed in older women

    Directory of Open Access Journals (Sweden)

    Hsu Chun

    2010-05-01

    Full Text Available Abstract Background Improved usual gait speed predicts substantial reduction in mortality. A better understanding of the modifiable factors that are independently associated with improved gait speed would ensure that intervention strategies are developed based on a valid theoretical framework. Thus, we examined the independent association of change in executive functions and change in falls-related self-efficacy with improved gait speed among community-dwelling senior women. Methods A secondary analysis of the 135 senior women aged 65 to 75 years old who completed a 12-month randomized controlled trial of resistance training. Usual gait speed was assessed using a 4-meter walk. Three executive processes were assessed by standard neuropsychological tests: 1 set shifting; 2 working memory; and 3 selective attention and response inhibition. A linear regression model was constructed to determine the independent association of change in executive functions and falls-related self-efficacy with change in gait speed. Results Improved selective attention and conflict resolution, and falls-related self-efficacy, were independently associated with improved gait speed after accounting for age, global cognition, baseline gait speed, and change in quadriceps strength. The total variance explained was 24%. Conclusions Interventions that target executive functions and falls-related self-efficacy, in addition to physical functions, to improve gait speed may be more efficacious than those that do not. Trial Registration ClinicalTrials.gov Identifier: NCT00426881

  13. Physical Inactivity Predicts Slow Gait Speed in an Elderly Multi-Ethnic Cohort Study: The Northern Manhattan Study.

    Science.gov (United States)

    Willey, Joshua Z; Moon, Yeseon P; Kulick, Erin R; Cheung, Ying Kuen; Wright, Clinton B; Sacco, Ralph L; Elkind, Mitchell S V

    2017-01-01

    Gait speed is associated with multiple adverse outcomes of aging. We hypothesized that physical inactivity would be prospectively inversely associated with gait speed independently of white matter hyperintensity volume and silent brain infarcts on MRI. Participants in the Northern Manhattan Study MRI sub-study had physical activity assessed when they were enrolled into the study. A mean of 5 years after the MRI, participants had gait speed measured via a timed 5-meter walk test. Physical inactivity was defined as reporting no leisure-time physical activity. Multi-variable logistic and quantile regression was performed to examine the associations between physical inactivity and future gait speed adjusted for confounders. Among 711 participants with MRI and gait speed measures (62% women, 71% Hispanic, mean age 74.1 ± 8.4), the mean gait speed was 1.02 ± 0.26 m/s. Physical inactivity was associated with a greater odds of gait speed in the lowest quartile (Physical inactivity is associated with slower gait speed independently of osteoarthritis, grip strength, and subclinical ischemic brain injury. Modifying sedentary behavior poses a target for interventions aimed at reducing decline in mobility. © 2017 S. Karger AG, Basel.

  14. Walks on SPR neighborhoods.

    Science.gov (United States)

    Caceres, Alan Joseph J; Castillo, Juan; Lee, Jinnie; St John, Katherine

    2013-01-01

    A nearest-neighbor-interchange (NNI)-walk is a sequence of unrooted phylogenetic trees, T1, T2, . . . , T(k) where each consecutive pair of trees differs by a single NNI move. We give tight bounds on the length of the shortest NNI-walks that visit all trees in a subtree-prune-and-regraft (SPR) neighborhood of a given tree. For any unrooted, binary tree, T, on n leaves, the shortest walk takes Θ(n²) additional steps more than the number of trees in the SPR neighborhood. This answers Bryant’s Second Combinatorial Challenge from the Phylogenetics Challenges List, the Isaac Newton Institute, 2011, and the Penny Ante Problem List, 2009.

  15. Performance of a six-legged planetary rover - Power, positioning, and autonomous walking

    Science.gov (United States)

    Krotkov, Eric; Simmons, Reid

    The authors quantify several performance metrics for the Ambler, a six-legged robot configured for autonomous traversal of Mars-like terrain. They present power consumption measures for walking on sandy terrain and for vertical lifts at different velocities. They document the accuracy of a novel dead reckoning approach, and analyze the accuracy. They describe the results of autonomous walking experiments in terms of terrain traversed, walking speed, number of instructions executed and endurance.

  16. Fitness Club / Nordic Walking

    CERN Multimedia

    Fitness Club

    2011-01-01

    Nordic Walking at CERN Enrollments are open for Nordic Walking courses and outings at CERN. Classes will be on Tuesdays as of 20 September, and outings for the more experienced will be on Thursdays as of 15 September. We meet at the CERN Club barracks car park (near entrance A). • 18:00 to 19:00 on 20 & 27 September, as well as 4 & 11 October. Check out our schedule and rates and enroll at: http://cern.ch/club-fitness Hope to see you among us! CERN Fitness Club fitness.club@cern.ch  

  17. Physiological aspect walking and Nordic walking as adequate kinetic activities.

    OpenAIRE

    BENEŠ, Václav

    2010-01-01

    This bachelor thesis on the topic of The Physiological Aspect of Walking and Nordic Walking as an adequate physical activity focuses on chosen physiological changes of an organism during a five-month training cycle. In the theoretical part I describe the physiological changes of organism during a regularly repeated strain, and also the technique of walking, Nordic walking and health benefits of these activities are defined here. The research part of the thesis describes the measurement method...

  18. Walking adaptability therapy after stroke: study protocol for a randomized controlled trial.

    Science.gov (United States)

    Timmermans, Celine; Roerdink, Melvyn; van Ooijen, Marielle W; Meskers, Carel G; Janssen, Thomas W; Beek, Peter J

    2016-08-26

    Walking in everyday life requires the ability to adapt walking to the environment. This adaptability is often impaired after stroke, and this might contribute to the increased fall risk after stroke. To improve safe community ambulation, walking adaptability training might be beneficial after stroke. This study is designed to compare the effects of two interventions for improving walking speed and walking adaptability: treadmill-based C-Mill therapy (therapy with augmented reality) and the overground FALLS program (a conventional therapy program). We hypothesize that C-Mill therapy will result in better outcomes than the FALLS program, owing to its expected greater amount of walking practice. This is a single-center parallel group randomized controlled trial with pre-intervention, post-intervention, retention, and follow-up tests. Forty persons after stroke (≥3 months) with deficits in walking or balance will be included. Participants will be randomly allocated to either C-Mill therapy or the overground FALLS program for 5 weeks. Both interventions will incorporate practice of walking adaptability and will be matched in terms of frequency, duration, and therapist attention. Walking speed, as determined by the 10 Meter Walking Test, will be the primary outcome measure. Secondary outcome measures will pertain to walking adaptability (10 Meter Walking Test with context or cognitive dual-task and Interactive Walkway assessments). Furthermore, commonly used clinical measures to determine walking ability (Timed Up-and-Go test), walking independence (Functional Ambulation Category), balance (Berg Balance Scale), and balance confidence (Activities-specific Balance Confidence scale) will be used, as well as a complementary set of walking-related assessments. The amount of walking practice (the number of steps taken per session) will be registered using the treadmill's inbuilt step counter (C-Mill therapy) and video recordings (FALLS program). This process measure will

  19. Displacement of the pelvis during human walking : experimental data and model predictions

    NARCIS (Netherlands)

    Zijlstra, W; Hof, AL

    1997-01-01

    Displacements of the pelvis during treadmill walking were studied in dependence of walking speed, stride frequency and stride length. Displacement curves per stride cycle were described by means of harmonic analysis. Simple mechanical, or geometrical models of the body's center of mass (COM)

  20. Within-day variability on short and long walking tests in persons with multiple sclerosis

    NARCIS (Netherlands)

    Feys, P.; Bibby, B.; Romberg, A.; Santoyo, C.; Gebara, B.; de Noordhout, B.M.; Knuts, K.; Bethoux, F.; Skjerbaek, A.; Jensen, E.; Baert, I.; Vaney, C.; de Groot, V.; Dalgas, U.

    2014-01-01

    Objective To compare within-day variability of short (10 m walking test at usual and fastest speed; 10MWT) and long (2 and 6-minute walking test; 2MWT/6MWT) tests in persons with multiple sclerosis. Design Observational study. Setting MS rehabilitation and research centers in Europe and US within

  1. Locomotor sequence learning in visually guided walking

    DEFF Research Database (Denmark)

    Choi, Julia T; Jensen, Peter; Nielsen, Jens Bo

    2016-01-01

    walking. In addition, we determined how age (i.e., healthy young adults vs. children) and biomechanical factors (i.e., walking speed) affected the rate and magnitude of locomotor sequence learning. The results showed that healthy young adults (age 24 ± 5 years, N = 20) could learn a specific sequence...... of step lengths over 300 training steps. Younger children (age 6-10 years, N = 8) have lower baseline performance, but their magnitude and rate of sequence learning was the same compared to older children (11-16 years, N = 10) and healthy adults. In addition, learning capacity may be more limited...... to modify step length from one trial to the next. Our sequence learning paradigm is derived from the serial reaction-time (SRT) task that has been used in upper limb studies. Both random and ordered sequences of step lengths were used to measure sequence-specific and sequence non-specific learning during...

  2. Speeding up or slowing down?: Gait adaptations to preserve gait stability in response to balance perturbations

    NARCIS (Netherlands)

    Hak, L.; Houdijk, J.H.P.; Steenbrink, F.; van der Wurff, P.; Beek, P.J.; van Dieen, J.H.

    2012-01-01

    It has frequently been proposed that lowering walking speed is a strategy to enhance gait stability and to decrease the probability of falling. However, previous studies have not been able to establish a clear relation between walking speed and gait stability. We investigated whether people do

  3. Treadmill training and body weight support for walking after stroke.

    Science.gov (United States)

    Mehrholz, Jan; Thomas, Simone; Elsner, Bernhard

    2017-08-17

    Treadmill training, with or without body weight support using a harness, is used in rehabilitation and might help to improve walking after stroke. This is an update of the Cochrane review first published in 2003 and updated in 2005 and 2014. To determine if treadmill training and body weight support, individually or in combination, improve walking ability, quality of life, activities of daily living, dependency or death, and institutionalisation or death, compared with other physiotherapy gait-training interventions after stroke. The secondary objective was to determine the safety and acceptability of this method of gait training. We searched the Cochrane Stroke Group Trials Register (last searched 14 February 2017), the Cochrane Central Register of Controlled Trials (CENTRAL) and the Database of Reviews of Effects (DARE) (the Cochrane Library 2017, Issue 2), MEDLINE (1966 to 14 February 2017), Embase (1980 to 14 February 2017), CINAHL (1982 to 14 February 2017), AMED (1985 to 14 February 2017) and SPORTDiscus (1949 to 14 February 2017). We also handsearched relevant conference proceedings and ongoing trials and research registers, screened reference lists, and contacted trialists to identify further trials. Randomised or quasi-randomised controlled and cross-over trials of treadmill training and body weight support, individually or in combination, for the treatment of walking after stroke. Two review authors independently selected trials, extracted data, and assessed risk of bias and methodological quality. The primary outcomes investigated were walking speed, endurance, and dependency. We included 56 trials with 3105 participants in this updated review. The average age of the participants was 60 years, and the studies were carried out in both inpatient and outpatient settings. All participants had at least some walking difficulties and many could not walk without assistance. Overall, the use of treadmill training did not increase the chances of walking

  4. Walking to transit.

    Science.gov (United States)

    2011-12-01

    Using a real-life setting, WalkBostons project focused on developing and testing techniques to broaden the scope and range of public participation in transportation planning in a large neighborhood in Boston. The team explored methods of seeking o...

  5. Walking along water

    DEFF Research Database (Denmark)

    Rasmussen, Mattias Borg

    2014-01-01

    Steep slopes, white peaks and deep valleys make up the Andes. As phenomenologists of landscape have told us, different people have different landscapes. By moving across the terrain, walking along, we might get a sense of how this has been carved out by the movement of wind and water, tectonics...

  6. Effect of subjective knee-joint pain on the laterality of knee extension strength and gait in elderly women.

    Science.gov (United States)

    Sugiura, Hiroki; Demura, Shinichi

    2012-01-01

    This study aimed to examine the effect of subjective knee-joint pain on the laterality of knee extension strength and gait in elderly women. The subjects were 144 elderly women (62-94 years old; mean age 76.2±6.0 years; ±S.D.) who were divided into the following groups: 81 persons without knee-pain (no knee-pain group), 39 persons with the subjective pain in right or left knee (single knee-pain group), and 24 persons with the subjective pain in both knees (double knee-pain group). The subjects took a knee extension strength test and a 12 m maximum effort walk test. Knee extension strength, stance time, swing time, stride length, step length and swing speed were selected as parameters. A significant laterality was found in knee extension strength only in the one knee-pain group. The laterality of gait parameters was not found in all groups. In conclusion, elderly women who can perform daily living activity independently, even though having subjective pain in either knee or laterality in knee extension strength exertion show little laterality of gait during short distance walking. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  7. Functional roles of lower-limb joint moments while walking in water.

    Science.gov (United States)

    Miyoshi, Tasuku; Shirota, Takashi; Yamamoto, Shin-Ichiro; Nakazawa, Kimitaka; Akai, Masami

    2005-02-01

    To clarify the functional roles of lower-limb joint moments and their contribution to support and propulsion tasks while walking in water compared with that on land. Sixteen healthy, young subjects walked on land and in water at several different speeds with and without additional loads. Walking in water is a major rehabilitation therapy for patients with orthopedic disorders. However, the functional role of lower-limb joint moments while walking in water is still unclear. Kinematics, electromyographic activities in biceps femoris and gluteus maximums, and ground reaction forces were measured under the following conditions: walking on land and in water at a self-determined pace, slow walking on land, and fast walking in water with or without additional loads (8 kg). The hip, knee, and ankle joint moments were calculated by inverse dynamics. The contribution of the walking speed increased the hip extension moment, and the additional weight increased the ankle plantar flexion and knee extension moment. The major functional role was different in each lower-limb joint muscle. That of the muscle group in the ankle is to support the body against gravity, and that of the muscle group involved in hip extension is to contribute to propulsion. In addition, walking in water not only reduced the joint moments but also completely changed the inter-joint coordination. It is of value for clinicians to be aware that the greater the viscosity of water produces a greater load on the hip joint when fast walking in water.

  8. Walking football as sustainable exercise for older adults - A pilot investigation.

    Science.gov (United States)

    Reddy, Peter; Dias, Irundika; Holland, Carol; Campbell, Niyah; Nagar, Iaysha; Connolly, Luke; Krustrup, Peter; Hubball, Harry

    2017-06-01

    The health benefits of playing football and the importance of exercise and social contact for healthy ageing are well established, but few older adults in the UK take enough exercise. Football is popular, flexible in format and draws players into engrossing, effortful and social exercise, but the physical demands of play at full speed may make it unsustainable for some older adults. Restricted to walking pace, will play still be engaging? Will health benefits be retained? Will physical demands remain manageable? This pilot study aims to investigate: (1) the experience of older adults playing walking football every week, is it sustainable and rewarding, (2) the intensity and locomotor pattern of walking football, (3) the scale and nature of walking football health benefits and (4) possible cognitive benefits of playing walking football through measures of processing speed, selective and divided attention and updating and inhibition components of executive function.
 'Walking football' and 'waiting list' groups were compared before and after 12 weeks of one-hour per week football. Walking football was found to be engaging, sustainable for older adults and moderately intensive; however, selective health and cognitive benefits were not found from this brief intervention. Highlights Walking football is a lower impact but authentic form of football that enables older players to extend their active participation. Walking football is enjoyable and moderately demanding and may be a sustainable form of exercise for older adults. Health and cognitive benefits to playing walking football were not found.

  9. Walking and Sensing Mobile Lives

    DEFF Research Database (Denmark)

    Bødker, Mads; Meinhardt, Nina Dam

    In this position paper, we discuss how mindful walking with people allow us to explore sensory aspects of mobile lives that are typically absent from research. We present an app that aids researchers collect impressions from a walk.......In this position paper, we discuss how mindful walking with people allow us to explore sensory aspects of mobile lives that are typically absent from research. We present an app that aids researchers collect impressions from a walk....

  10. Kineziologická charakteristika Nordic Walking

    OpenAIRE

    Pospíšilová, Petra

    2009-01-01

    Title: Functional a physiological characteristics of Nordic Walking Purposes: The aim of the thesis is to describe and summarize current knowledge about Nordic Walking Methods: Literature analysis Key words: Nordic Walking, free bipedal walk, health benefits, functional indicator changes

  11. Physical factors underlying the association between lower walking performance and falls in older people: a structural equation model.

    Science.gov (United States)

    Shimada, Hiroyuki; Tiedemann, Anne; Lord, Stephen R; Suzukawa, Megumi; Makizako, Hyuma; Kobayashi, Kumiko; Suzuki, Takao

    2011-01-01

    The purpose of this study was to determine the interrelationships between lower limb muscle performance, balance, gait and falls in older people using structural equation modeling. Study participants were two hundred and thirteen people aged 65 years and older (mean age, 80.0 ± 7.1 years), who used day-care services in Japan. The outcome measures were the history of falls three months retrospectively and physical risk factors for falling, including performance in the chair stand test (CST), one-leg standing test (OLS), tandem walk test, 6m walking time, and the timed up-and-go (TUG) test. Thirty-nine (18.3%) of the 213 participants had fallen at least one or more times during the preceding 3 months. The fall group had significantly slower 6m walking speed and took significantly longer to undertake the TUG test than the non-fall group. In a structural equation model, performance in the CST contributed significantly to gait function, and low gait function was significantly and directly associated with falls in older people. This suggests that task-specific strength exercise as well as general mobility retraining should be important components of exercise programs designed to reduce falls in older people. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  12. Modeling pedestrian crossing speed profiles considering speed change behavior for the safety assessment of signalized intersections.

    Science.gov (United States)

    Iryo-Asano, Miho; Alhajyaseen, Wael K M

    2017-11-01

    Pedestrian safety is one of the most challenging issues in road networks. Understanding how pedestrians maneuver across an intersection is the key to applying countermeasures against traffic crashes. It is known that the behaviors of pedestrians at signalized crosswalks are significantly different from those in ordinary walking spaces, and they are highly influenced by signal indication, potential conflicts with vehicles, and intersection geometries. One of the most important characteristics of pedestrian behavior at crosswalks is the possible sudden speed change while crossing. Such sudden behavioral change may not be expected by conflicting vehicles, which may lead to hazardous situations. This study aims to quantitatively model the sudden speed changes of pedestrians as they cross signalized crosswalks under uncongested conditions. Pedestrian speed profiles are collected from empirical data and speed change events are extracted assuming that the speed profiles are stepwise functions. The occurrence of speed change events is described by a discrete choice model as a function of the necessary walking speed to complete crossing before the red interval ends, current speed, and the presence of turning vehicles in the conflict area. The amount of speed change before and after the event is modeled using regression analysis. A Monte Carlo simulation is applied for the entire speed profile of the pedestrians. The results show that the model can represent the pedestrian travel time distribution more accurately than the constant speed model. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Body weight-supported treadmill training vs. overground walking training for persons with chronic stroke: a pilot randomized controlled trial.

    Science.gov (United States)

    Combs-Miller, Stephanie A; Kalpathi Parameswaran, Anu; Colburn, Dawn; Ertel, Tara; Harmeyer, Amanda; Tucker, Lindsay; Schmid, Arlene A

    2014-09-01

    To compare the effects of body weight-supported treadmill training and overground walking training when matched for task and dose (duration/frequency/intensity) on improving walking function, activity, and participation after stroke. Single-blind, pilot randomized controlled trial with three-month follow-up. University and community settings. A convenience sample of participants (N = 20) at least six months post-stroke and able to walk independently were recruited. Thirty-minute walking interventions (body weight-supported treadmill training or overground walking training) were administered five times a week for two weeks. Intensity was monitored with the Borg Rating of Perceived Exertion Scale at five-minute increments to maintain a moderate training intensity. Walking speed (comfortable/fast 10-meter walk), walking endurance (6-minute walk), spatiotemporal symmetry, and the ICF Measure of Participation and ACTivity were assessed before, immediately after, and three months following the intervention. The overground walking training group demonstrated significantly greater improvements in comfortable walking speed compared with the body weight-supported treadmill training group immediately (change of 0.11 m/s vs. 0.06 m/s, respectively; p = 0.047) and three months (change of 0.14 m/s vs. 0.08 m/s, respectively; p = 0.029) after training. Only the overground walking training group significantly improved comfortable walking speed (p = 0.001), aspects of gait symmetry (p = 0.032), and activity (p = 0.003) immediately after training. Gains were maintained at the three-month follow-up (p training was more beneficial than body weight-supported treadmill training at improving self-selected walking speed for the participants in this study. © The Author(s) 2014.

  14. Variability of leg kinematics during overground walking in persons with chronic incomplete spinal cord injury.

    Science.gov (United States)

    Sohn, Won Joon; Tan, Andrew Q; Hayes, Heather B; Pochiraju, Saahith; Deffeyes, Joan; Trumbower, Randy D

    2018-03-20

    Incomplete spinal cord injury (iSCI) often leads to partial disruption of spinal pathways that are important for motor control of walking. Persons with iSCI present with deficits in walking ability due, in part, to inconsistent leg kinematics during stepping. While kinematic variability is important for normal walking, growing evidence indicates that excessive variability may limit walking ability and increase reliance on assistive devices (AD) after iSCI. The purpose of this study was to assess the effects of iSCI-induced impairments on kinematic variability during overground walking. We hypothesized that iSCI results in greater variability of foot and joint displacement during overground walking compared to controls. We further hypothesized that variability is larger in persons with limited walking speed and greater reliance on ADs. To test these hypotheses, iSCI and control subjects walked overground. Kinematic variability was quantified as step-to-step foot placement variability (endpoint), and variability in hip-knee, hip-ankle, and knee-ankle joint space (angular coefficient of correspondence; ACC). We characterized sensitivity of kinematic variability to cadence, auditory cue, and AD. Supporting our hypothesis, persons with iSCI exhibited greater kinematic variability than controls, which scaled with deficits in overground walking speed (pvariability, and with walking speed, indicates both are markers of walking performance. Moreover, hip-knee and hip-ankle ACC discriminated between AD use, indicating that ACC may capture AD-specific control strategies. We conclude that increased variability of foot and joint displacement are indicative of motor impairment severity and may serve as therapeutic targets to restore walking after iSCI.

  15. [Walking abnormalities in children].

    Science.gov (United States)

    Segawa, Masaya

    2010-11-01

    Walking is a spontaneous movement termed locomotion that is promoted by activation of antigravity muscles by serotonergic (5HT) neurons. Development of antigravity activity follows 3 developmental epochs of the sleep-wake (S-W) cycle and is modulated by particular 5HT neurons in each epoch. Activation of antigravity activities occurs in the first epoch (around the age of 3 to 4 months) as restriction of atonia in rapid eye movement (REM) stage and development of circadian S-W cycle. These activities strengthen in the second epoch, with modulation of day-time sleep and induction of crawling around the age of 8 months and induction of walking by 1 year. Around the age of 1 year 6 months, absence of guarded walking and interlimb cordination is observed along with modulation of day-time sleep to once in the afternoon. Bipedal walking in upright position occurs in the third epoch, with development of a biphasic S-W cycle by the age of 4-5 years. Patients with infantile autism (IA), Rett syndrome (RTT), or Tourette syndrome (TS) show failure in the development of the first, second, or third epoch, respectively. Patients with IA fail to develop interlimb coordination; those with RTT, crawling and walking; and those with TS, walking in upright posture. Basic pathophysiology underlying these condition is failure in restricting atonia in REM stage; this induces dysfunction of the pedunculopontine nucleus and consequently dys- or hypofunction of the dopamine (DA) neurons. DA hypofunction in the developing brain, associated with compensatory upward regulation of the DA receptors causes psychobehavioral disorders in infancy (IA), failure in synaptogenesis in the frontal cortex and functional development of the motor and associate cortexes in late infancy through the basal ganglia (RTT), and failure in functional development of the prefrontal cortex through the basal ganglia (TS). Further, locomotion failure in early childhood causes failure in development of functional

  16. Exoskeleton Motion Control for Children Walking Rehabilitation

    Directory of Open Access Journals (Sweden)

    Cristina Ploscaru

    2016-06-01

    Full Text Available This paper introduces a quick method for motion control of an exoskeleton used on children walking rehabilitation with ages between four to seven years old. The exoskeleton used on this purpose has six servomotors which work independently and actuates each human lower limb joints (hips, knees and ankles. For obtaining the desired motion laws, a high-speed motion analysis equipment was used. The experimental rough data were mathematically modeled in order to obtain the proper motion equations for controlling the exoskeleton servomotors.

  17. Acute Cardiorespiratory and Metabolic Responses During Exoskeleton-Assisted Walking Overground Among Persons with Chronic Spinal Cord Injury.

    Science.gov (United States)

    Evans, Nicholas; Hartigan, Clare; Kandilakis, Casey; Pharo, Elizabeth; Clesson, Ismari

    2015-01-01

    Lower extremity robotic exoskeleton technology is being developed with the promise of affording people with spinal cord injury (SCI) the opportunity to stand and walk. The mobility benefits of exoskeleton-assisted walking can be realized immediately, however the cardiorespiratory and metabolic benefits of this technology have not been thoroughly investigated. The purpose of this pilot study was to evaluate the acute cardiorespiratory and metabolic responses associated with exoskeleton-assisted walking overground and to determine the degree to which these responses change at differing walking speeds. Five subjects (4 male, 1 female) with chronic SCI (AIS A) volunteered for the study. Expired gases were collected during maximal graded exercise testing and two, 6-minute bouts of exoskeleton-assisted walking overground. Outcome measures included peak oxygen consumption (V̇O2peak), average oxygen consumption (V̇O2avg), peak heart rate (HRpeak), walking economy, metabolic equivalent of tasks for SCI (METssci), walk speed, and walk distance. Significant differences were observed between walk-1 and walk-2 for walk speed, total walk distance, V̇O2avg, and METssci. Exoskeleton-assisted walking resulted in %V̇O2peak range of 51.5% to 63.2%. The metabolic cost of exoskeleton-assisted walking ranged from 3.5 to 4.3 METssci. Persons with motor-complete SCI may be limited in their capacity to perform physical exercise to the extent needed to improve health and fitness. Based on preliminary data, cardiorespiratory and metabolic demands of exoskeleton-assisted walking are consistent with activities performed at a moderate intensity.

  18. Acute Cardiorespiratory and Metabolic Responses During Exoskeleton-Assisted Walking Overground Among Persons with Chronic Spinal Cord Injury

    Science.gov (United States)

    Hartigan, Clare; Kandilakis, Casey; Pharo, Elizabeth; Clesson, Ismari

    2015-01-01

    Background: Lower extremity robotic exoskeleton technology is being developed with the promise of affording people with spinal cord injury (SCI) the opportunity to stand and walk. The mobility benefits of exoskeleton-assisted walking can be realized immediately, however the cardiorespiratory and metabolic benefits of this technology have not been thoroughly investigated. Objective: The purpose of this pilot study was to evaluate the acute cardiorespiratory and metabolic responses associated with exoskeleton-assisted walking overground and to determine the degree to which these responses change at differing walking speeds. Methods: Five subjects (4 male, 1 female) with chronic SCI (AIS A) volunteered for the study. Expired gases were collected during maximal graded exercise testing and two, 6-minute bouts of exoskeleton-assisted walking overground. Outcome measures included peak oxygen consumption (V̇O2peak), average oxygen consumption (V̇O2avg), peak heart rate (HRpeak), walking economy, metabolic equivalent of tasks for SCI (METssci), walk speed, and walk distance. Results: Significant differences were observed between walk-1 and walk-2 for walk speed, total walk distance, V̇O2avg, and METssci. Exoskeleton-assisted walking resulted in %V̇O2peak range of 51.5% to 63.2%. The metabolic cost of exoskeleton-assisted walking ranged from 3.5 to 4.3 METssci. Conclusion: Persons with motor-complete SCI may be limited in their capacity to perform physical exercise to the extent needed to improve health and fitness. Based on preliminary data, cardiorespiratory and metabolic demands of exoskeleton-assisted walking are consistent with activities performed at a moderate intensity. PMID:26364281

  19. Speed mathematics

    CERN Document Server

    Handley, Bill

    2012-01-01

    This new, revised edition of the bestselling Speed Mathematics features new chapters on memorising numbers and general information, calculating statistics and compound interest, square roots, logarithms and easy trig calculations. Written so anyone can understand, this book teaches simple strategies that will enable readers to make lightning-quick calculations. People who excel at mathematics use better strategies than the rest of us; they are not necessarily more intelligent. With Speed Mathematics you'll discover methods to make maths easy and fun. This book is perfect for stud

  20. Mind your step: metabolic energy cost while walking an enforced gait pattern.

    Science.gov (United States)

    Wezenberg, D; de Haan, A; van Bennekom, C A M; Houdijk, H

    2011-04-01

    The energy cost of walking could be attributed to energy related to the walking movement and energy related to balance control. In order to differentiate between both components we investigated the energy cost of walking an enforced step pattern, thereby perturbing balance while the walking movement is preserved. Nine healthy subjects walked three times at comfortable walking speed on an instrumented treadmill. The first trial consisted of unconstrained walking. In the next two trials, subject walked while following a step pattern projected on the treadmill. The steps projected were either composed of the averaged step characteristics (periodic trial), or were an exact copy including the variability of the steps taken while walking unconstrained (variable trial). Metabolic energy cost was assessed and center of pressure profiles were analyzed to determine task performance, and to gain insight into the balance control strategies applied. Results showed that the metabolic energy cost was significantly higher in both the periodic and variable trial (8% and 13%, respectively) compared to unconstrained walking. The variation in center of pressure trajectories during single limb support was higher when a gait pattern was enforced, indicating a more active ankle strategy. The increased metabolic energy cost could originate from increased preparatory muscle activation to ensure proper foot placement and a more active ankle strategy to control for lateral balance. These results entail that metabolic energy cost of walking can be influenced significantly by control strategies that do not necessary alter global gait characteristics. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. Gait speed as a measure of functional status in COPD patients

    Directory of Open Access Journals (Sweden)

    Karpman C

    2014-11-01

    Full Text Available Craig Karpman, Roberto Benzo Mindful Breathing Laboratory, Mayo Clinic, Division of Pulmonary and Critical Care Medicine, Rochester, MN, USA Abstract: Chronic obstructive pulmonary disease (COPD is a disease associated with dyspnea, fatigue, and exercise intolerance. The degree of functional debility and level of exercise capacity greatly influences quality of life and mortality in patients with COPD, and the measures of exercise capacity are to be an integral part of patient assessment but often not feasible in routine daily practice, resulting in likely suboptimal care. There is a need for simple ways to identify functional decline in the clinical setting in order to guide resources to preventive interventions or proper care, including palliative care. Gait speed, or measuring how long it takes for a patient to walk a short distance, takes very little time and space, and can serve as a candidate measure of physical function in COPD. Gait speed has been shown to be an indicator of disability, health care utilization, and survival in older adults. It is a simple, reliable, and feasible measure to perform in the clinic and has been promoted as the next vital sign, providing insight into patients' functional capacity. Gait speed is mainly determined by exercise capacity but reflects global well-being as it captures many of the multisystemic effects of disease severity in COPD rather than pulmonary impairment alone. It is an excellent screening measure for exercise capacity and frailty; in COPD, the usual gait speed (4-m course with rolling start has been very accurate in identifying clinically relevant benchmarks of the 6-minute walk test, poor (<350 m and very poor (<200 m 6-minute walk test distances. A specific cut-off point of 0.8 m⋅s-1 had a positive predictive value of 69% and negative predictive value of 98% in predicting very poor exercise capacity. The increasing evidence on gait speed is promising as a simple test that can inform the

  2. Nordic Walking Classes

    CERN Multimedia

    Fitness Club

    2015-01-01

    Four classes of one hour each are held on Tuesdays. RDV barracks parking at Entrance A, 10 minutes before class time. Spring Course 2015: 05.05/12.05/19.05/26.05 Prices 40 CHF per session + 10 CHF club membership 5 CHF/hour pole rental Check out our schedule and enroll at: https://espace.cern.ch/club-fitness/Lists/Nordic%20Walking/NewForm.aspx? Hope to see you among us! fitness.club@cern.ch

  3. Familiarity with music increases walking speed in rhythmic auditory cuing.

    Science.gov (United States)

    Leow, Li-Ann; Rinchon, Cricia; Grahn, Jessica

    2015-03-01

    Rhythmic auditory stimulation (RAS) is a gait rehabilitation method in which patients synchronize footsteps to a metronome or musical beats. Although RAS with music can ameliorate gait abnormalities, outcomes vary, possibly because music properties, such as groove or familiarity, differ across interventions. To optimize future interventions, we assessed how initially familiar and unfamiliar low-groove and high-groove music affected synchronization accuracy and gait in healthy individuals. We also experimentally increased music familiarity using repeated exposure to initially unfamiliar songs. Overall, familiar music elicited faster stride velocity and less variable strides, as well as better synchronization performance (matching of step tempo to beat tempo). High-groove music, as reported previously, led to faster stride velocity than low-groove music. We propose two mechanisms for familiarity's effects. First, familiarity with the beat structure reduces cognitive demands of synchronizing, leading to better synchronization performance and faster, less variable gait. Second, familiarity might have elicited faster gait by increasing enjoyment of the music, as enjoyment was higher after repeated exposure to initially low-enjoyment songs. Future studies are necessary to dissociate the contribution of these mechanisms to the observed RAS effects of familiar music on gait. © 2015 New York Academy of Sciences.

  4. Perceived neighbourhood environmental attributes associated with adults׳ recreational walking

    DEFF Research Database (Denmark)

    Sugiyama, Takemi; Cerin, Ester; Owen, Neville

    2014-01-01

    This study examined the strength and shape of associations between perceived environmental attributes and adults' recreational walking, using data collected from 13,745 adult participants in 12 countries. Perceived residential density, land use mix, street connectivity, aesthetics, safety from cr...

  5. Ways of Walking

    DEFF Research Database (Denmark)

    Eslambolchilar, Parisa; Bødker, Mads; Chamberlain, Alan

    2016-01-01

    It seems logical to argue that mobile computing technologies are intended for use "on-the-go." However, on closer inspection, the use of mobile technologies pose a number of challenges for users who are mobile, particularly moving around on foot. In engaging with such mobile technologies and thei......It seems logical to argue that mobile computing technologies are intended for use "on-the-go." However, on closer inspection, the use of mobile technologies pose a number of challenges for users who are mobile, particularly moving around on foot. In engaging with such mobile technologies...... and their envisaged development, we argue that interaction designers must increasingly consider a multitude of perspectives that relate to walking in order to frame design problems appropriately. In this paper, we consider a number of perspectives on walking, and we discuss how these may inspire the design of mobile...... technologies. Drawing on insights from non-representational theory, we develop a partial vocabulary with which to engage with qualities of pedestrian mobility, and we outline how taking more mindful approaches to walking may enrich and inform the design space of handheld technologies....

  6. Does walking strategy in older people change as a function of walking distance?

    Science.gov (United States)

    Najafi, Bijan; Helbostad, Jorunn L; Moe-Nilssen, Rolf; Zijlstra, Wiebren; Aminian, Kamiar

    2009-02-01

    This study investigates whether the spatio-temporal parameters of gait in the elderly vary as a function of walking distance. The gait pattern of older subjects (n=27) over both short (SWDLWD>20 m) walking was evaluated using an ambulatory device consisting of body-worn sensors (Physilog). The stride velocity (SV), gait cycle time (GCT), and inter-cycle variability of each parameter (CV) were evaluated for each subject. Analysis was undertaken after evaluating the errors and the test-retest reliability of the Physilog device compared with an electronic walkway system (GaitRite) over the SWD with different walking speeds. While both systems were highly reliable with respect to the SV and GCT parameters (ICC>0.82), agreement for the gait variability was poor. Interestingly, our data revealed that the measured gait parameters over SWD and LWD were significantly different. LWD trials had a mean increase of 5.2% (pLWD trials decreased by an average of 1% relative to the SWD case, the drop was not significant. Moreover, reliability for gait variability measures was poor, irrespective of the instrument and despite a moderate improvement for LWD trials. Taken together, our findings indicate that for valid and reliable comparisons, test and retest should be performed under identical distance conditions. Furthermore, our findings suggest that the older subjects may choose different walking strategies for SWD and LWD conditions.

  7. Kinematic Adaptations of Forward and Backward Walking on Land and in Water

    Directory of Open Access Journals (Sweden)

    Cadenas-Sanchez Cristina

    2015-12-01

    Full Text Available The aim of this study was to compare sagittal plane lower limb kinematics during walking on land and submerged to the hip in water. Eight healthy adults (age 22.1 ± 1.1 years, body height 174.8 ± 7.1 cm, body mass 63.4 ± 6.2 kg were asked to cover a distance of 10 m at comfortable speed with controlled step frequency, walking forward or backward. Sagittal plane lower limb kinematics were obtained from three dimensional video analysis to compare spatiotemporal gait parameters and joint angles at selected events using two-way repeated measures ANOVA. Key findings were a reduced walking speed, stride length, step length and a support phase in water, and step length asymmetry was higher compared to the land condition (p<0.05. At initial contact, knees and hips were more flexed during walking forward in water, whilst, ankles were more dorsiflexed during walking backward in water. At final stance, knees and ankles were more flexed during forward walking, whilst the hip was more flexed during backward walking. These results show how walking in water differs from walking on land, and provide valuable insights into the development and prescription of rehabilitation and training programs.

  8. How humans use visual optic flow to regulate stepping during walking.

    Science.gov (United States)

    Salinas, Mandy M; Wilken, Jason M; Dingwell, Jonathan B

    2017-09-01

    Humans use visual optic flow to regulate average walking speed. Among many possible strategies available, healthy humans walking on motorized treadmills allow fluctuations in stride length (L n ) and stride time (T n ) to persist across multiple consecutive strides, but rapidly correct deviations in stride speed (S n =L n /T n ) at each successive stride, n. Several experiments verified this stepping strategy when participants walked with no optic flow. This study determined how removing or systematically altering optic flow influenced peoples' stride-to-stride stepping control strategies. Participants walked on a treadmill with a virtual reality (VR) scene projected onto a 3m tall, 180° semi-cylindrical screen in front of the treadmill. Five conditions were tested: blank screen ("BLANK"), static scene ("STATIC"), or moving scene with optic flow speed slower than ("SLOW"), matched to ("MATCH"), or faster than ("FAST") walking speed. Participants took shorter and faster strides and demonstrated increased stepping variability during the BLANK condition compared to the other conditions. Thus, when visual information was removed, individuals appeared to walk more cautiously. Optic flow influenced both how quickly humans corrected stride speed deviations and how successful they were at enacting this strategy to try to maintain approximately constant speed at each stride. These results were consistent with Weber's law: healthy adults more-rapidly corrected stride speed deviations in a no optic flow condition (the lower intensity stimuli) compared to contexts with non-zero optic flow. These results demonstrate how the temporal characteristics of optic flow influence ability to correct speed fluctuations during walking. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Comparison of the metabolic energy cost of overground and treadmill walking in older adults.

    Science.gov (United States)

    Berryman, Nicolas; Gayda, Mathieu; Nigam, Anil; Juneau, Martin; Bherer, Louis; Bosquet, Laurent

    2012-05-01

    We assessed whether the metabolic energy cost of walking was higher when measured overground or on a treadmill in a population of healthy older adults. We also assessed the association between the two testing modes. Participants (n = 20, 14 men and 6 women aged between 65 and 83 years of age) were randomly divided into two groups. Half of them went through the overground-treadmill sequence while the other half did the opposite order. A familiarization visit was held for each participant prior to the actual testing. For both modes of testing, five walking speeds were experimented (0.67, 0.89, 1.11, 1.33 and 1.67 m s(-1)). Oxygen uptake was monitored for all walking speeds. We found a significant difference between treadmill and track metabolic energy cost of walking, whatever the walking speed. The results show that walking on the treadmill requires more metabolic energy than walking overground for all experimental speeds (P < 0.05). The association between both measures was low to moderate (0.17 < ICC < 0.65), and the standard error of measurement represented 6.9-15.7% of the average value. These data indicate that metabolic energy cost of walking results from a treadmill test does not necessarily apply in daily overground activities. Interventions aiming at reducing the metabolic energy cost of walking should be assessed with the same mode as it was proposed during the intervention. If the treadmill mode is necessary for any purposes, functional overground walking tests should be implemented to obtain a more complete and specific evaluation.

  10. Association between stride time fractality and gait adaptability during unperturbed and asymmetric walking.

    Science.gov (United States)

    Ducharme, Scott W; Liddy, Joshua J; Haddad, Jeffrey M; Busa, Michael A; Claxton, Laura J; van Emmerik, Richard E A

    2018-04-01

    Human locomotion is an inherently complex activity that requires the coordination and control of neurophysiological and biomechanical degrees of freedom across various spatiotemporal scales. Locomotor patterns must constantly be altered in the face of changing environmental or task demands, such as heterogeneous terrains or obstacles. Variability in stride times occurring at short time scales (e.g., 5-10 strides) is statistically correlated to larger fluctuations occurring over longer time scales (e.g., 50-100 strides). This relationship, known as fractal dynamics, is thought to represent the adaptive capacity of the locomotor system. However, this has not been tested empirically. Thus, the purpose of this study was to determine if stride time fractality during steady state walking associated with the ability of individuals to adapt their gait patterns when locomotor speed and symmetry are altered. Fifteen healthy adults walked on a split-belt treadmill at preferred speed, half of preferred speed, and with one leg at preferred speed and the other at half speed (2:1 ratio asymmetric walking). The asymmetric belt speed condition induced gait asymmetries that required adaptation of locomotor patterns. The slow speed manipulation was chosen in order to determine the impact of gait speed on stride time fractal dynamics. Detrended fluctuation analysis was used to quantify the correlation structure, i.e., fractality, of stride times. Cross-correlation analysis was used to measure the deviation from intended anti-phasing between legs as a measure of gait adaptation. Results revealed no association between unperturbed walking fractal dynamics and gait adaptability performance. However, there was a quadratic relationship between perturbed, asymmetric walking fractal dynamics and adaptive performance during split-belt walking, whereby individuals who exhibited fractal scaling exponents that deviated from 1/f performed the poorest. Compared to steady state preferred walking

  11. On your feet: protocol for a randomized controlled trial to compare the effects of pole walking and regular walking on physical and psychosocial health in older adults.

    Science.gov (United States)

    Fritschi, Juliette O; Brown, Wendy J; van Uffelen, Jannique G Z

    2014-04-17

    Physical activity is associated with better physical and mental health in older adults. Pole walking is a form of walking which may have additional health benefits in older adults, because of the addition of hand held poles, and consequent upper limb involvement. However, few studies have examined the potential additional effects of pole walking on physical and psychosocial health in older adults compared with walking. The aim of this study is to compare the effect of a pole walking program with the effects of a walking program, on physical and psychosocial wellbeing, in older adults in assisted living facilities. Sixty men and women from assisted living communities over 65 years will be recruited from senior retirement facilities and randomized into a group based, pole walking program, or walking program. The pole walking group will use the Exerstrider method of pole walking. Total duration of the programs is 12 weeks, with three sessions per week, building from 20 minute to 30 minute sessions.The primary outcome is physical function, as measured by items from the Seniors Fitness Test and hand grip strength. Secondary outcomes include, physical activity levels, sedentary behaviour, joint pain, and quality of life. All outcomes will be assessed before and after the programs, using valid and reliable measures. The study will add to the evidence base for the effects of pole walking, compared with walking, on physical and psychosocial health and physical function, in healthy older adults. This will improve understanding about the feasibility of pole walking programs and its specific benefits in this population. Australian New Zealand Clinical Trials Registry ACTRN12612001127897.

  12. Moderate-Load Muscular Endurance Strength Training Did Not Improve Peak Power or Functional Capacity in Older Men and Women

    Directory of Open Access Journals (Sweden)

    Simon Walker

    2017-09-01

    Full Text Available The present study determined the effects of muscular endurance strength training on maximum strength and power, functional capacity, muscle activation and hypertrophy in older men and women. Eighty-one men and women acted as an intervention group while 22 acted as non-training controls (age range 64–75 y. Intervention training included super-sets (i.e., paired exercises, immediately performing the second exercises following completion of the first with short rest intervals (30–60 s between sets at an intensity of 50–60% one-repetition maximum (1-RM for 15–20 repetitions. Concentric leg press actions measured maximum strength (1-RM and concentric peak power. Functional capacity was assessed by maximum speed walking tests (i.e., forward walk, backward walk, timed-up-and-go, and stair climb tests. Quadriceps muscle activation was assessed by surface electromyogram and twitch interpolation technique. Vastus lateralis cross-sectional area was measured by panoramic ultrasound. Compared to control, the intervention groups increased maximum strength (1-RM; men: 10 ± 7% vs. 2 ± 3%, women: 14 ± 9% vs. 1 ± 6% both P < 0.01 and vastus lateralis cross-sectional area (men: 6 ± 7% vs. −3 ± 6%, women: 10 ± 10% vs. 0 ± 4% both P < 0.05. But there were no between-group differences in peak power, muscle activation or functional capacity (e.g., stair climb; men: −5 ± 7% vs. −4 ± 3%, women: −5 ± 6% vs. −2 ± 5% both P > 0.05. While benefits occurred during muscular endurance strength training, specific stimuli are probably needed to target all aspects of age-related health.

  13. The Effect of Foot Progression Angle on Knee Joint Compression Force during Walking

    DEFF Research Database (Denmark)

    Baldvinsson, Henrik Koblauch; Heilskov-Hansen, Thomas; Alkjær, Tine

    2013-01-01

    males walked at a fixed speed of 4.5 km/h under three conditions: Normal walking, internally rotated and externally rotated. All gait-trials were recorded by six infrared cameras. Net joint moments were calculated by 3D inverse dynamics. The results revealed that the medial knee joint compartment......It is unclear how rotations of the lower limb affect the knee joint compression forces during walking. Increases in the frontal plane knee moment have been reported when walking with internally rotated feet and a decrease when walking with externally rotated feet. The aim of this study...... was to investigate the knee joint compressive forces during walking with internal, external and normal foot rotation and to determine if the frontal plane knee joint moment is an adequate surrogate for the compression forces in the medial and lateral knee joint compartments under such gait modifications. Ten healthy...

  14. Lévy Walks Suboptimal under Predation Risk.

    Directory of Open Access Journals (Sweden)

    Masato S Abe

    2015-11-01

    Full Text Available A key challenge in movement ecology is to understand how animals move in nature. Previous studies have predicted that animals should perform a special class of random walks, called Lévy walk, to obtain more targets. However, some empirical studies did not support this hypothesis, and the relationship between search strategy and ecological factors is still unclear. We focused on ecological factors, such as predation risk, and analyzed whether Lévy walk may not be favored. It was remarkable that the ecological factors often altered an optimal search strategy from Lévy walk to Brownian walk, depending on the speed of the predator's movement, density of predators, etc. This occurred because higher target encounter rates simultaneously led searchers to higher predation risks. Our findings indicate that animals may not perform Lévy walks often, and we suggest that it is crucial to consider the ecological context for evaluating the search strategy performed by animals in the field.

  15. Lévy Walks Suboptimal under Predation Risk

    Science.gov (United States)

    Abe, Masato S.; Shimada, Masakazu

    2015-01-01

    A key challenge in movement ecology is to understand how animals move in nature. Previous studies have predicted that animals should perform a special class of random walks, called Lévy walk, to obtain more targets. However, some empirical studies did not support this hypothesis, and the relationship between search strategy and ecological factors is still unclear. We focused on ecological factors, such as predation risk, and analyzed whether Lévy walk may not be favored. It was remarkable that the ecological factors often altered an optimal search strategy from Lévy walk to Brownian walk, depending on the speed of the predator’s movement, density of predators, etc. This occurred because higher target encounter rates simultaneously led searchers to higher predation risks. Our findings indicate that animals may not perform Lévy walks often, and we suggest that it is crucial to consider the ecological context for evaluating the search strategy performed by animals in the field. PMID:26544687

  16. Wind speed perception and risk.

    Directory of Open Access Journals (Sweden)

    Duzgun Agdas

    Full Text Available BACKGROUND: How accurately do people perceive extreme wind speeds and how does that perception affect the perceived risk? Prior research on human-wind interaction has focused on comfort levels in urban settings or knock-down thresholds. No systematic experimental research has attempted to assess people's ability to estimate extreme wind speeds and perceptions of their associated risks. METHOD: We exposed 76 people to 10, 20, 30, 40, 50, and 60 mph (4.5, 8.9, 13.4, 17.9, 22.3, and 26.8 m/s winds in randomized orders and asked them to estimate wind speed and the corresponding risk they felt. RESULTS: Multilevel modeling showed that people were accurate at lower wind speeds but overestimated wind speeds at higher levels. Wind speed perceptions mediated the direct relationship between actual wind speeds and perceptions of risk (i.e., the greater the perceived wind speed, the greater the perceived risk. The number of tropical cyclones people had experienced moderated the strength of the actual-perceived wind speed relationship; consequently, mediation was stronger for people who had experienced fewer storms. CONCLUSION: These findings provide a clearer understanding of wind and risk perception, which can aid development of public policy solutions toward communicating the severity and risks associated with natural disasters.

  17. Wind speed perception and risk.

    Science.gov (United States)

    Agdas, Duzgun; Webster, Gregory D; Masters, Forrest J

    2012-01-01

    How accurately do people perceive extreme wind speeds and how does that perception affect the perceived risk? Prior research on human-wind interaction has focused on comfort levels in urban settings or knock-down thresholds. No systematic experimental research has attempted to assess people's ability to estimate extreme wind speeds and perceptions of their associated risks. We exposed 76 people to 10, 20, 30, 40, 50, and 60 mph (4.5, 8.9, 13.4, 17.9, 22.3, and 26.8 m/s) winds in randomized orders and asked them to estimate wind speed and the corresponding risk they felt. Multilevel modeling showed that people were accurate at lower wind speeds but overestimated wind speeds at higher levels. Wind speed perceptions mediated the direct relationship between actual wind speeds and perceptions of risk (i.e., the greater the perceived wind speed, the greater the perceived risk). The number of tropical cyclones people had experienced moderated the strength of the actual-perceived wind speed relationship; consequently, mediation was stronger for people who had experienced fewer storms. These findings provide a clearer understanding of wind and risk perception, which can aid development of public policy solutions toward communicating the severity and risks associated with natural disasters.

  18. Wind Speed Perception and Risk

    Science.gov (United States)

    Agdas, Duzgun; Webster, Gregory D.; Masters, Forrest J.

    2012-01-01

    Background How accurately do people perceive extreme wind speeds and how does that perception affect the perceived risk? Prior research on human–wind interaction has focused on comfort levels in urban settings or knock-down thresholds. No systematic experimental research has attempted to assess people's ability to estimate extreme wind speeds and perceptions of their associated risks. Method We exposed 76 people to 10, 20, 30, 40, 50, and 60 mph (4.5, 8.9, 13.4, 17.9, 22.3, and 26.8 m/s) winds in randomized orders and asked them to estimate wind speed and the corresponding risk they felt. Results Multilevel modeling showed that people were accurate at lower wind speeds but overestimated wind speeds at higher levels. Wind speed perceptions mediated the direct relationship between actual wind speeds and perceptions of risk (i.e., the greater the perceived wind speed, the greater the perceived risk). The number of tropical cyclones people had experienced moderated the strength of the actual–perceived wind speed relationship; consequently, mediation was stronger for people who had experienced fewer storms. Conclusion These findings provide a clearer understanding of wind and risk perception, which can aid development of public policy solutions toward communicating the severity and risks associated with natural disasters. PMID:23226230

  19. Callosal hyperintensities and gait speed gain from two types of mobility interventions in older adults.

    Science.gov (United States)

    Nadkarni, Neelesh K; Perera, Subashan; Studenski, Stephanie A; Rosano, Caterina; Aizenstein, Howard J; VanSwearingen, Jessie M

    2015-06-01

    To assess whether the volume of callosal hyperintensities in the genu and splenium of older adults with mobility impairment is differentially associated with the degree of gain in gait speed after 2 types of gait interventions. Single-blind randomized controlled trial of 2 types of gait exercises in older adults. Research center in an academic institution. Ambulatory adults (N=44) aged ≥65 years with a slow and variable gait. Twelve-week physical therapist-guided trial of a conventional walking, endurance, balance, and strength (WEBS) intervention (n=20) versus a timing and coordination of gait (TC) intervention (n=22). Gain in gait speed after the intervention and its relation to callosal hyperintensities in the genu and splenium of the corpus callosum. Gait speed improved in both the WEBS group (mean change, 0.16m/s) and the TC group (mean change, 0.21m/s; both PMobility impaired older adults with genual hyperintensities may benefit from a rehabilitation program focused on motor skill learning rather than on strength and endurance training. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  20. Rugged Walking Robot

    Science.gov (United States)

    Larimer, Stanley J.; Lisec, Thomas R.; Spiessbach, Andrew J.

    1990-01-01

    Proposed walking-beam robot simpler and more rugged than articulated-leg walkers. Requires less data processing, and uses power more efficiently. Includes pair of tripods, one nested in other. Inner tripod holds power supplies, communication equipment, computers, instrumentation, sampling arms, and articulated sensor turrets. Outer tripod holds mast on which antennas for communication with remote control site and video cameras for viewing local and distant terrain mounted. Propels itself by raising, translating, and lowering tripods in alternation. Steers itself by rotating raised tripod on turntable.

  1. Random walk loop soup

    OpenAIRE

    Lawler, Gregory F.; Ferreras, José A. Trujillo

    2004-01-01

    The Brownian loop soup introduced in Lawler and Werner (2004) is a Poissonian realization from a sigma-finite measure on unrooted loops. This measure satisfies both conformal invariance and a restriction property. In this paper, we define a random walk loop soup and show that it converges to the Brownian loop soup. In fact, we give a strong approximation result making use of the strong approximation result of Koml\\'os, Major, and Tusn\\'ady. To make the paper self-contained, we include a proof...

  2. A mathematical nature walk

    CERN Document Server

    Adam, John A

    2009-01-01

    How heavy is that cloud? Why can you see farther in rain than in fog? Why are the droplets on that spider web spaced apart so evenly? If you have ever asked questions like these while outdoors, and wondered how you might figure out the answers, this is a book for you. An entertaining and informative collection of fascinating puzzles from the natural world around us, A Mathematical Nature Walk will delight anyone who loves nature or math or both. John Adam presents ninety-six questions about many common natural phenomena--and a few uncommon ones--and then shows how to answer them using mostly b

  3. Stair-Walking Performance in Adolescents with Intellectual Disabilities

    Directory of Open Access Journals (Sweden)

    Wann-Yun Shieh

    2016-07-01

    Full Text Available Most individuals with intellectual disabilities (ID demonstrate problems in learning and movement coordination. Consequently, they usually have difficulties in activities such as standing, walking, and stair climbing. To monitor the physical impairments of these children, regular gross motor evaluation is crucial. Straight-line level walking is the most frequently used test of their mobility. However, numerous studies have found that unless the children have multiple disabilities, no significant differences can be found between the children with ID and typically-developed children in this test. Stair climbing presents more challenges than level walking because it is associated with numerous physical factors, including lower extremity strength, cardiopulmonary endurance, vision, balance, and fear of falling. Limited ability in those factors is one of the most vital markers for children with ID. In this paper, we propose a sensor-based approach for measuring stair-walking performance, both upstairs and downstairs, for adolescents with ID. Particularly, we address the problem of sensor calibration to ensure measurement accuracy. In total, 62 participants aged 15 to 21 years, namely 32 typically-developed (TD adolescents, 20 adolescents with ID, and 10 adolescents with multiple disabilities (MD, participated. The experimental results showed that stair-walking is more sensitive than straight-line level walking in capturing gait characteristics for adolescents with ID.

  4. Physical implementation of quantum walks

    CERN Document Server

    Manouchehri, Kia

    2013-01-01

    Given the extensive application of random walks in virtually every science related discipline, we may be at the threshold of yet another problem solving paradigm with the advent of quantum walks. Over the past decade, quantum walks have been explored for their non-intuitive dynamics, which may hold the key to radically new quantum algorithms. This growing interest has been paralleled by a flurry of research into how one can implement quantum walks in laboratories. This book presents numerous proposals as well as actual experiments for such a physical realization, underpinned by a wide range of

  5. Quantum walks with entangled coins

    International Nuclear Information System (INIS)

    Venegas-Andraca, S E; Ball, J L; Burnett, K; Bose, S

    2005-01-01

    We present a mathematical formalism for the description of un- restricted quantum walks with entangled coins and one walker. The numerical behaviour of such walks is examined when using a Bell state as the initial coin state, with two different coin operators, two different shift operators, and one walker. We compare and contrast the performance of these quantum walks with that of a classical random walk consisting of one walker and two maximally correlated coins as well as quantum walks with coins sharing different degrees of entanglement. We illustrate that the behaviour of our walk with entangled coins can be very different in comparison to the usual quantum walk with a single coin. We also demonstrate that simply by changing the shift operator, we can generate widely different distributions. We also compare the behaviour of quantum walks with maximally entangled coins with that of quantum walks with non-entangled coins. Finally, we show that the use of different shift operators on two and three qubit coins leads to different position probability distributions in one- and two-dimensional graphs

  6. Joint forces and torques when walking in shallow water.

    Science.gov (United States)

    Orselli, Maria Isabel Veras; Duarte, Marcos

    2011-04-07

    This study reports for the first time an estimation of the internal net joint forces and torques on adults' lower limbs and pelvis when walking in shallow water, taking into account the drag forces generated by the movement of their bodies in the water and the equivalent data when they walk on land. A force plate and a video camera were used to perform a two-dimensional gait analysis at the sagittal plane of 10 healthy young adults walking at comfortable speeds on land and in water at a chest-high level. We estimated the drag force on each body segment and the joint forces and torques at the ankle, knee, and hip of the right side of their bodies using inverse dynamics. The observed subjects' apparent weight in water was about 35% of their weight on land and they were about 2.7 times slower when walking in water. When the subjects walked in water compared with walking on land, there were no differences in the angular displacements but there was a significant reduction in the joint torques which was related to the water's depth. The greatest reduction was observed for the ankle and then the knee and no reduction was observed for the hip. All joint powers were significantly reduced in water. The compressive and shear joint forces were on average about three times lower during walking in water than on land. These quantitative results substantiate the use of water as a safe environment for practicing low-impact exercises, particularly walking. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Random-walk enzymes

    Science.gov (United States)

    Mak, Chi H.; Pham, Phuong; Afif, Samir A.; Goodman, Myron F.

    2015-09-01

    Enzymes that rely on random walk to search for substrate targets in a heterogeneously dispersed medium can leave behind complex spatial profiles of their catalyzed conversions. The catalytic signatures of these random-walk enzymes are the result of two coupled stochastic processes: scanning and catalysis. Here we develop analytical models to understand the conversion profiles produced by these enzymes, comparing an intrusive model, in which scanning and catalysis are tightly coupled, against a loosely coupled passive model. Diagrammatic theory and path-integral solutions of these models revealed clearly distinct predictions. Comparison to experimental data from catalyzed deaminations deposited on single-stranded DNA by the enzyme activation-induced deoxycytidine deaminase (AID) demonstrates that catalysis and diffusion are strongly intertwined, where the chemical conversions give rise to new stochastic trajectories that were absent if the substrate DNA was homogeneous. The C →U deamination profiles in both analytical predictions and experiments exhibit a strong contextual dependence, where the conversion rate of each target site is strongly contingent on the identities of other surrounding targets, with the intrusive model showing an excellent fit to the data. These methods can be applied to deduce sequence-dependent catalytic signatures of other DNA modification enzymes, with potential applications to cancer, gene regulation, and epigenetics.

  8. The quantum Levy walk

    International Nuclear Information System (INIS)

    Caceres, Manuel O; Nizama, Marco

    2010-01-01

    We introduce the quantum Levy walk to study transport and decoherence in a quantum random model. We have derived from second-order perturbation theory the quantum master equation for a Levy-like particle that moves along a lattice through scale-free hopping while interacting with a thermal bath of oscillators. The general evolution of the quantum Levy particle has been solved for different preparations of the system. We examine the evolution of the quantum purity, the localized correlation and the probability to be in a lattice site, all of them leading to important conclusions concerning quantum irreversibility and decoherence features. We prove that the quantum thermal mean-square displacement is finite under a constraint that is different when compared to the classical Weierstrass random walk. We prove that when the mean-square displacement is infinite the density of state has a complex null-set inside the Brillouin zone. We show the existence of a critical behavior in the continuous eigenenergy which is related to its non-differentiability and self-affine characteristics. In general, our approach allows us to study analytically quantum fluctuations and decoherence in a long-range hopping model.

  9. Energy costs and performance of transfemoral amputees and non-amputees during walking and running: A pilot study.

    Science.gov (United States)

    Mengelkoch, Larry J; Kahle, Jason T; Highsmith, M Jason

    2017-10-01

    Limited information is available concerning the effects of prosthetic foot components on energy costs and ambulatory performance for transfemoral amputees. Compare energy costs (VO 2 ; gait economy) and ambulatory performance (self-selected walking speeds, self-selected running speeds, peak running speeds) differences during walking and running for transfemoral amputees and matched, non-amputee runners. Repeated measures. Transfemoral amputees were accommodated and tested with three prosthetic feet: conventional foot, solid-ankle cushioned heel (SACH); energy storing and return foot, Renegade; and running-specific energy storing and return foot, Nitro. During walking, VO 2 was similar between transfemoral amputees but was increased compared to controls. Self-selected walking speeds were slower for SACH compared to Renegade and Nitro. For transfemoral amputees, gait economy was decreased and self-selected walking speeds were slower compared to controls. During fixed running speeds, transfemoral amputees ran using Nitro, and VO 2 was greater compared to controls. Transfemoral amputees ran at self-selected running speeds using Renegade and Nitro. Self-selected running speeds were slower for Renegade compared to Nitro. For transfemoral amputees, gait economy was decreased and self-selected running speeds were slower compared to controls. VO 2 peak was similar between transfemoral amputees and controls, but controls achieved greater peak running speeds and % grade. Energy costs were greater and ambulatory performance was lower for transfemoral amputees compared to matched, non-amputee controls for all prosthetic foot conditions. Clinical relevance Both types of energy storing and return feet may improve walking performance for transfemoral amputees by providing faster self-selected walking speeds. For transfemoral amputees interested in performing vigorous running (exercise and running competition), clinicians should recommend a running-specific energy storing and

  10. Using GPS, accelerometry and heart rate to predict outdoor graded walking energy expenditure.

    Science.gov (United States)

    de Müllenheim, P-Y; Chaudru, S; Emily, M; Gernigon, M; Mahé, G; Bickert, S; Prioux, J; Noury-Desvaux, B; Le Faucheur, A

    2018-02-01

    To determine the best method and combination of methods among global positioning system (GPS), accelerometry, and heart rate (HR) for estimating energy expenditure (EE) during level and graded outdoor walking. Thirty adults completed 6-min outdoor walks at speeds of 2.0, 3.5, and 5.0kmh -1 during three randomized outdoor walking sessions: one level walking session and two graded (uphill and downhill) walking sessions on a 3.4% and a 10.4% grade. EE was measured using a portable metabolic system (K4b 2 ). Participants wore a GlobalSat ® DG100 GPS receiver, an ActiGraph™ wGT3X+ accelerometer, and a Polar ® HR monitor. Linear mixed models (LMMs) were tested for EE predictions based on GPS speed and grade, accelerometer counts or HR-related parameters (alone and combined). Root-mean-square error (RMSE) was used to determine the accuracy of the models. Published speed/grade-, count-, and HR-based equations were also cross-validated. According to the LMMs, GPS was as accurate as accelerometry (RMSE=0.89-0.90kcalmin -1 ) and more accurate than HR (RMSE=1.20kcalmin -1 ) for estimating EE during level walking; GPS was the most accurate method for estimating EE during both level and uphill (RMSE=1.34kcalmin -1 )/downhill (RMSE=0.84kcalmin -1 ) walking; combining methods did not increase the accuracy reached using GPS (or accelerometry for level walking). The cross-validation results were in accordance with the LMMs, except for downhill walking. Our study provides useful information regarding the best method(s) for estimating EE with appropriate equations during level and graded outdoor walking. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  11. Risk of falls in older people during fast-walking--the TASCOG study.

    Science.gov (United States)

    Callisaya, M L; Blizzard, L; McGinley, J L; Srikanth, V K

    2012-07-01

    To investigate the relationship between fast-walking and falls in older people. Individuals aged 60-86 years were randomly selected from the electoral roll (n=176). Gait speed, step length, cadence and a walk ratio were recorded during preferred- and fast-walking using an instrumented walkway. Falls were recorded prospectively over 12 months. Log multinomial regression was used to estimate the relative risk of single and multiple falls associated with gait variables during fast-walking and change between preferred- and fast-walking. Covariates included age, sex, mood, physical activity, sensorimotor and cognitive measures. The risk of multiple falls was increased for those with a smaller walk ratio (shorter steps, faster cadence) during fast-walking (RR 0.92, CI 0.87, 0.97) and greater reduction in the walk ratio (smaller increase in step length, larger increase in cadence) when changing to fast-walking (RR 0.73, CI 0.63, 0.85). These gait patterns were associated with poorer physiological and cognitive function (prisk of multiple falls was also seen for those in the fastest quarter of gait speed (p=0.01) at fast-walking. A trend for better reaction time, balance, memory and physical activity for higher categories of gait speed was stronger for fallers than non-fallers (prisk of multiple falls. There may be two distinct groups at risk--the frail person with short shuffling steps, and the healthy person exposed to greater risk. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Influence of water depth on energy expenditure during aquatic walking in people post stroke.

    Science.gov (United States)

    Lim, Hyosok; Azurdia, Daniel; Jeng, Brenda; Jung, Taeyou

    2018-05-11

    This study aimed to investigate the metabolic cost during aquatic walking at various depths in people post stroke. The secondary purpose was to examine the differences in metabolic cost between aquatic walking and land walking among individuals post stroke. A cross-sectional research design is used. Twelve participants post stroke (aged 55.5 ± 13.3 years) completed 6 min of walking in 4 different conditions: chest-depth, waist-depth, and thigh-depth water, and land. Data were collected on 4 separate visits with at least 48 hr in between. On the first visit, all participants were asked to walk in chest-depth water at their fastest speed. The walking speed was used as a reference speed, which was applied to the remaining 3 walking conditions. The order of remaining walking conditions was randomized. Energy expenditure (EE), oxygen consumption (VO 2 ), and minute ventilation (V E ) were measured with a telemetric metabolic system. Our findings showed statistically significant differences in EE, VO 2 , and V E among the 4 different walking conditions: chest-depth, waist-depth, and thigh-depth water, and land (all p stroke consume less energy in chest-depth water, which may allow them to perform prolonged duration of training. Thigh-depth water demonstrated greater EE compared with other water depths; thus, it can be recommended for time-efficient cardiovascular exercise. Waist-depth water showed similar EE to land walking, which may have been contributed by the countervailing effects of buoyancy and water resistance. Copyright © 2018 John Wiley & Sons, Ltd.

  13. Task difficulty has no effect on haptic anchoring during tandem walking in young and older adults.

    Science.gov (United States)

    Costa, Andréia Abud da Silva; Santos, Luciana Oliveira Dos; Mauerberg-deCastro, Eliane; Moraes, Renato

    2018-02-14

    This study assessed the contribution of the "anchor system's" haptic information to balance control during walking at two levels of difficulty. Seventeen young adults and seventeen older adults performed 20 randomized trials of tandem walking in a straight line, on level ground and on a slightly-raised balance beam, both with and without the use of the anchors. The anchor consists of two flexible cables, whose ends participants hold in each hand, to which weights (125 g) are attached at the opposing ends, and which rest on the ground. As the participants walk, they pull on the cables, dragging the anchors. Spatiotemporal gait variables (step speed and single- and double-support duration) were processed using retro-reflective markers on anatomical sites. An accelerometer positioned in the cervical region registered trunk acceleration. Walking on the balance beam increased single- and double-support duration and reduced step speed in older adults, which suggests that this condition was more difficult than walking on the level ground. The anchors reduced trunk acceleration in the frontal plane, but the level of difficulty of the walking task showed no effect. Thus, varying the difficulty of the task had no influence on the way in which participants used the anchor system while tandem walking. The older adults exhibited more difficulty in walking on the balance beam as compared to the younger adults; however, the effect of the anchor system was similar in both groups. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Older adults adopted more cautious gait patterns when walking in socks than barefoot.

    Science.gov (United States)

    Tsai, Yi-Ju; Lin, Sang-I

    2013-01-01

    Walking barefoot or in socks is common for ambulating indoors and has been reported to be associated with increased risk of falls and related injuries in the elderly. This study sought to determine if gait patterns differed between these two conditions for young and older adults. A motion analysis system was used to record and calculate the stride characteristics and motion of the body's center of mass (COM) of 21 young and 20 older adults. For the walking tasks, the participants walked on a smooth floor surface at their preferred speed either barefoot or in socks in a random order. The socks were commercially available and commonly used. The results demonstrated that while walking in socks, compared with walking barefoot, older adults adopted a more cautious gait pattern including decreased walking speed and shortened stride length as well as reduced COM minimal velocity during the single limb support phase. Young adults, however, did not demonstrate significant changes. These findings suggest that walking with socks might present a greater balance threat for older adults. Clinically, safety precautions about walking in socks should be considered to be given to older adults, especially those with balance deficits. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Effects of upper body parameters on biped walking efficiency studied by dynamic optimization

    Directory of Open Access Journals (Sweden)

    Kang An

    2016-12-01

    Full Text Available Walking efficiency is one of the considerations for designing biped robots. This article uses the dynamic optimization method to study the effects of upper body parameters, including upper body length and mass, on walking efficiency. Two minimal actuations, hip joint torque and push-off impulse, are used in the walking model, and minimal constraints are set in a free search using the dynamic optimization. Results show that there is an optimal solution of upper body length for the efficient walking within a range of walking speed and step length. For short step length, walking with a lighter upper body mass is found to be more efficient and vice versa. It is also found that for higher speed locomotion, the increase of the upper body length and mass can make the walking gait optimal rather than other kind of gaits. In addition, the typical strategy of an optimal walking gait is that just actuating the swing leg at the beginning of the step.

  16. Walking Tips for Older Adults

    Science.gov (United States)

    ... you can continue your walking program. Don’t let a cane or walker stop you It’s OK to use your cane or walker if you already have one. These can improve your balance and help take the load off painful joints. Aim for the right pace Try to walk as fast as you ...

  17. Fractal fluctuations in spatiotemporal variables when walking on a self-paced treadmill.

    Science.gov (United States)

    Choi, Jin-Seung; Kang, Dong-Won; Seo, Jeong-Woo; Tack, Gye-Rae

    2017-12-08

    This study investigated the fractal dynamic properties of stride time (ST), stride length (SL) and stride speed (SS) during walking on a self-paced treadmill (STM) in which the belt speed is automatically controlled by the walking speed. Twelve healthy young subjects participated in the study. The subjects walked at their preferred walking speed under four conditions: STM, STM with a metronome (STM+met), fixed-speed (conventional) treadmill (FTM), and FTM with a metronome (FTM+met). To compare the fractal dynamics between conditions, the mean, variability, and fractal dynamics of ST, SL, and SS were compared. Moreover, the relationship among the variables was examined under each walking condition using three types of surrogates. The mean values of all variables did not differ between the two treadmills, and the variability of all variables was generally larger for STM than for FTM. The use of a metronome resulted in a decrease in variability in ST and SS for all conditions. The fractal dynamic characteristics of SS were maintained with STM, in contrast to FTM, and only the fractal dynamic characteristics of ST disappeared when using a metronome. In addition, the fractal dynamic patterns of the cross-correlated surrogate results were identical to those of all variables for the two treadmills. In terms of the fractal dynamic properties, STM walking was generally closer to overground walking than FTM walking. Although further research is needed, the present results will be useful in research on gait fractal dynamics and rehabilitation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Quantum walks and search algorithms

    CERN Document Server

    Portugal, Renato

    2013-01-01

    This book addresses an interesting area of quantum computation called quantum walks, which play an important role in building quantum algorithms, in particular search algorithms. Quantum walks are the quantum analogue of classical random walks. It is known that quantum computers have great power for searching unsorted databases. This power extends to many kinds of searches, particularly to the problem of finding a specific location in a spatial layout, which can be modeled by a graph. The goal is to find a specific node knowing that the particle uses the edges to jump from one node to the next. This book is self-contained with main topics that include: Grover's algorithm, describing its geometrical interpretation and evolution by means of the spectral decomposition of the evolution operater Analytical solutions of quantum walks on important graphs like line, cycles, two-dimensional lattices, and hypercubes using Fourier transforms Quantum walks on generic graphs, describing methods to calculate the limiting d...

  19. Doing the Data Walk

    Science.gov (United States)

    Cogger, Steve

    2015-01-01

    The traditional Run the Football Field physics activity--in which students are timed as they move at different speeds on a football field to investigate displacement and velocity--has been updated for the 21st century. Nowadays, GPS-enabled tablets and smartphones replace the stopwatches and yard markers of the past, allowing students to collect…

  20. walk around Irkutsk

    Directory of Open Access Journals (Sweden)

    Elena Grigoryeva

    2011-08-01

    Full Text Available It is noteworthy that this country develops through two types of events: either through a jubilee or through a catastrophe.It seems that Irkutsk Airport will be built only after the next crash. At least the interest to this problem returns regularly after sad events, and this occurs almost half a century (a jubilee, too! – the Council of Ministers decided to relocate the Airport away from the city as long ago as 1962. The Airport does not relate to the topic of this issue, but an attentive reader understands that it is our Carthage, and that the Airport should be relocated. The Romans coped with it faster and more effectively.Back to Irkutsk’s jubilee, we should say that we will do without blare of trumpets. We will just make an unpretentious walk around the city in its summer 350. Each our route covers new (some of them have been completed by the jubilee and old buildings, some of them real monuments. All these buildings are integrated into public spaces of different quality and age.We will also touch on the problems, for old houses, especially the wooden ones often provoke a greedy developer to demolish or to burn them down. Thus a primitive thrift estimates an output of additional square meters. Not to mention how attractive it is to seize public spaces without demolition or without reallocation of the dwellers. Or, rather, the one who is to preserve, to cherish and to improve such houses for the good of the citizens never speaks about this sensitive issue. So we have to do it.Walking is a no-hurry genre, unlike the preparation for the celebration. Walking around the city you like is a pleasant and cognitive process. It will acquaint the architects with the works of their predecessors and colleagues. We hope that such a walk may be interesting for Irkutsk citizens and visitors, too. Isn’t it interesting to learn “at first hand” the intimate details of the restoration of the Trubetskoys’ estate

  1. Human treadmill walking needs attention

    Directory of Open Access Journals (Sweden)

    Daniel Olivier

    2006-08-01

    Full Text Available Abstract Background The aim of the study was to assess the attentional requirements of steady state treadmill walking in human subjects using a dual task paradigm. The extent of decrement of a secondary (cognitive RT task provides a measure of the attentional resources required to maintain performance of the primary (locomotor task. Varying the level of difficulty of the reaction time (RT task is used to verify the priority of allocation of attentional resources. Methods 11 healthy adult subjects were required to walk while simultaneously performing a RT task. Participants were instructed to bite a pressure transducer placed in the mouth as quickly as possible in response to an unpredictable electrical stimulation applied on the back of the neck. Each subject was tested under five different experimental conditions: simple RT task alone and while walking, recognition RT task alone and while walking, walking alone. A foot switch system composed of a pressure sensitive sensor was placed under the heel and forefoot of each foot to determine the gait cycle duration. Results Gait cycle duration was unchanged (p > 0.05 by the addition of the RT task. Regardless of the level of difficulty of the RT task, the RTs were longer during treadmill walking than in sitting conditions (p 0.05 was found between the attentional demand of the walking task and the decrement of performance found in the RT task under varying levels of difficulty. This finding suggests that the healthy subjects prioritized the control of walking at the expense of cognitive performance. Conclusion We conclude that treadmill walking in young adults is not a purely automatic task. The methodology and outcome measures used in this study provide an assessment of the attentional resources required by walking on the treadmill at a steady state.

  2. Quantum walks on quotient graphs

    International Nuclear Information System (INIS)

    Krovi, Hari; Brun, Todd A.

    2007-01-01

    A discrete-time quantum walk on a graph Γ is the repeated application of a unitary evolution operator to a Hilbert space corresponding to the graph. If this unitary evolution operator has an associated group of symmetries, then for certain initial states the walk will be confined to a subspace of the original Hilbert space. Symmetries of the original graph, given by its automorphism group, can be inherited by the evolution operator. We show that a quantum walk confined to the subspace corresponding to this symmetry group can be seen as a different quantum walk on a smaller quotient graph. We give an explicit construction of the quotient graph for any subgroup H of the automorphism group and illustrate it with examples. The automorphisms of the quotient graph which are inherited from the original graph are the original automorphism group modulo the subgroup H used to construct it. The quotient graph is constructed by removing the symmetries of the subgroup H from the original graph. We then analyze the behavior of hitting times on quotient graphs. Hitting time is the average time it takes a walk to reach a given final vertex from a given initial vertex. It has been shown in earlier work [Phys. Rev. A 74, 042334 (2006)] that the hitting time for certain initial states of a quantum walks can be infinite, in contrast to classical random walks. We give a condition which determines whether the quotient graph has infinite hitting times given that they exist in the original graph. We apply this condition for the examples discussed and determine which quotient graphs have infinite hitting times. All known examples of quantum walks with hitting times which are short compared to classical random walks correspond to systems with quotient graphs much smaller than the original graph; we conjecture that the existence of a small quotient graph with finite hitting times is necessary for a walk to exhibit a quantum speedup

  3. Disorder and decoherence in coined quantum walks

    International Nuclear Information System (INIS)

    Zhang Rong; Qin Hao; Tang Bao; Xue Peng

    2013-01-01

    This article aims to provide a review on quantum walks. Starting form a basic idea of discrete-time quantum walks, we will review the impact of disorder and decoherence on the properties of quantum walks. The evolution of the standard quantum walks is deterministic and disorder introduces randomness to the whole system and change interference pattern leading to the localization effect. Whereas, decoherence plays the role of transmitting quantum walks to classical random walks. (topical review - quantum information)

  4. Walking drawings and walking ability in children with cerebral palsy.

    Science.gov (United States)

    Chong, Jimmy; Mackey, Anna H; Stott, N Susan; Broadbent, Elizabeth

    2013-06-01

    To investigate whether drawings of the self walking by children with cerebral palsy (CP) were associated with walking ability and illness perceptions. This was an exploratory study in 52 children with CP (M:F = 28:24), mean age 11.1 years (range 5-18), who were attending tertiary level outpatient clinics. Children were asked to draw a picture of themselves walking. Drawing size and content was used to investigate associations with clinical walk tests and children's own perceptions of their CP assessed using a CP version of the Brief Illness Perception Questionnaire. Larger drawings of the self were associated with less distance traveled, higher emotional responses to CP, and lower perceptions of pain or discomfort, independent of age. A larger self-to-overall drawing height ratio was related to walking less distance. Drawings of the self confined within buildings and the absence of other figures were also associated with reduced walking ability. Drawing size and content can reflect walking ability, as well as symptom perceptions and distress. Drawings may be useful for clinicians to use with children with cerebral palsy to aid discussion about their condition. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  5. Inpatient rehabilitation improves functional capacity, peripheral muscle strength and quality of life in patients with community-acquired pneumonia: a randomised trial

    Directory of Open Access Journals (Sweden)

    Anderson José

    2016-04-01

    Full Text Available Question: Among people who are hospitalised for community-acquired pneumonia, does an inpatient exercise-based rehabilitation program improve functional outcomes, symptoms, quality of life and length of hospital stay more than a respiratory physiotherapy regimen? Design: Randomised trial with concealed allocation, intention-to-treat analysis and blinding of some outcomes. Participants: Forty-nine adults hospitalised for community-acquired pneumonia. Intervention: The experimental group (n = 32 underwent a physical training program that included warm-up, stretching, peripheral muscle strength training and walking at a controlled speed for 15 minutes. The control group (n = 17 underwent a respiratory physiotherapy regimen that included percussion, vibrocompression, respiratory exercises and free walking. The intervention regimens lasted 8 days. Outcome measures: The primary outcome was the Glittre Activities of Daily Living test, which assesses the time taken to complete a series of functional tasks (eg, rising from a chair, walking, stairs, lifting and bending. Secondary outcomes were distance walked in the incremental shuttle walk test, peripheral muscle strength, quality of life, dyspnoea, lung function, C-reactive protein and length of hospital stay. Measures were taken 1 day before and 1 day after the intervention period. Results: There was greater improvement in the experimental group than in the control group on the Glittre Activities of Daily Living test (mean between-group difference 39 seconds, 95% CI 20 to 59 and the incremental shuttle walk test (mean between-group difference 130 m, 95% CI 77 to 182. There were also significantly greater improvements in quality of life, dyspnoea and peripheral muscle strength in the experimental group than in the control group. There were no between-group differences in lung function, C-reactive protein or length of hospital stay. Conclusion: The improvement in functional outcomes after an

  6. Exercise as a therapy for improvement of walking ability in adults with multiple sclerosis: a meta-analysis.

    Science.gov (United States)

    Pearson, Melissa; Dieberg, Gudrun; Smart, Neil

    2015-07-01

    To quantify improvements in walking performance commonly observed in patients with multiple sclerosis (pwMS), a systematic literature search and meta-analysis were conducted quantifying the expected benefits of exercise on walking ability in pwMS. Potential studies were identified by systematic search using PubMed (1966 to March 31, 2014), EMBASE (1974 to March 31, 2014), CINAHL (1998 to March 31, 2014), SPORTDiscus (1991 to March 31, 2014), and the Cochrane Central Register of Controlled Trials (1966 to March 31, 2014). The search used key concepts of "multiple sclerosis" AND "exercise." Randomized controlled trials of exercise training in adult pwMS. Data on patient and study characteristics, walking ability, 10-m walk test (10mWT), timed 25-foot walk test (T25FW), 2-minute walk test (2MWT), 6-minute walk test (6MWT), and timed Up and Go (TUG) were extracted and archived. Data from 13 studies were included. In pwMS who exercised, significant improvements were found in walking speed, measured by the 10mWT (mean difference [MD] reduction in walking time of -1.76s; 95% confidence interval [CI], -2.47 to -1.06; Pwalking endurance as measured by the 6MWT and 2MWT, with an increased walking distance of MD=36.46m (95% CI, 15.14-57.79; Pwalking speed and endurance in pwMS. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  7. Negligible motion artifacts in scalp electroencephalography (EEG during treadmill walking

    Directory of Open Access Journals (Sweden)

    Kevin eNathan

    2016-01-01

    Full Text Available Recent Mobile Brain/Body Imaging (MoBI techniques based on active electrode scalp electroencephalogram (EEG allow the acquisition and real-time analysis of brain dynamics during active unrestrained motor behavior involving whole body movements such as treadmill walking, over-ground walking and other locomotive and non-locomotive tasks. Unfortunately, MoBI protocols are prone to physiological and non-physiological artifacts, including motion artifacts that may contaminate the EEG recordings. A few attempts have been made to quantify these artifacts during locomotion tasks but with inconclusive results due in part to methodological pitfalls. In this paper, we investigate the potential contributions of motion artifacts in scalp EEG during treadmill walking at three different speeds (1.5, 3.0, and 4.5 km/h using a wireless 64 channel active EEG system and a wireless inertial sensor attached to the subject’s head. The experimental setup was designed according to good measurement practices using state-of-the-art commercially-available instruments, and the measurements were analyzed using Fourier analysis and wavelet coherence approaches. Contrary to prior claims, the subjects’ motion did not significantly affect their EEG during treadmill walking although precaution should be taken when gait speeds approach 4.5 km/h. Overall, these findings suggest how MoBI methods may be safely deployed in neural, cognitive, and rehabilitation engineering applications.

  8. High-speed scanning ablation of dental hard tissues with a λ = 9.3 μm CO2 laser: adhesion, mechanical strength, heat accumulation, and peripheral thermal damage

    Science.gov (United States)

    Nguyen, Daniel; Chang, Kwang; Hedayatollahnajafi, Saba; Staninec, Michal; Chan, Kenneth; Lee, Robert; Fried, Daniel

    2011-07-01

    CO2 lasers can be operated at high laser pulse repetition rates for the rapid and precise removal of dental decay. Excessive heat accumulation and peripheral thermal damage is a concern when using high pulse repetition rates. Peripheral thermal damage can adversely impact the mechanical strength of the irradiated tissue, particularly for dentin, and reduce the adhesion characteristics of the modified surfaces. The interpulpal temperature rise was recorded using microthermocouples situated at the roof of the pulp chamber on teeth that were occlusally ablated using a rapidly-scanned CO2 laser operating at 9.3 μm with a pulse duration of 10 to 15 μs and repetition rate of 300 Hz over a 2 min time course. The adhesion strength of laser treated enamel and dentin surfaces was measured for various laser scanning parameters with and without post-ablation acid etching using the single-plane shear test. The mechanical strength of laser-ablated dentin surfaces were determined via the four-point bend test and compared to control samples prepared with 320 grit wet sand paper to simulate conventional preparations. Thermocouple measurements indicated that the temperature remained below ambient temperature if water-cooling was used. There was no discoloration of either dentin or enamel laser treated surfaces, the surfaces were uniformly ablated, and there were no cracks visible. Four-point bend tests yielded mean mechanical strengths of 18.2 N (s.d. = 4.6) for ablated dentin and 18.1 N (s.d. = 2.7) for control (p > 0.05). Shear tests yielded mean bond strengths approaching 30 MPa for both enamel and dentin under certain irradiation conditions. These values were slightly lower than nonirradiated acid-etched control samples. Additional studies are needed to determine if the slightly lower bond strength than the acid-etched control samples is clinically significant. These measurements demonstrate that enamel and dentin surfaces can be rapidly ablated by CO2 lasers with minimal

  9. Walking execution is not affected by divided attention in patients with multiple sclerosis with no disability, but there is a motor planning impairment.

    Science.gov (United States)

    Nogueira, Leandro Alberto Calazans; Santos, Luciano Teixeira Dos; Sabino, Pollyane Galinari; Alvarenga, Regina Maria Papais; Thuler, Luiz Claudio Santos

    2013-08-01

    We analysed the cognitive influence on walking in multiple sclerosis (MS) patients, in the absence of clinical disability. A case-control study was conducted with 12 MS patients with no disability and 12 matched healthy controls. Subjects were referred for completion a timed walk test of 10 m and a 3D-kinematic analysis. Participants were instructed to walk at a comfortable speed in a dual-task (arithmetic task) condition, and motor planning was measured by mental chronometry. Scores of walking speed and cadence showed no statistically significant differences between the groups in the three conditions. The dual-task condition showed an increase in the double support duration in both groups. Motor imagery analysis showed statistically significant differences between real and imagined walking in patients. MS patients with no disability did not show any influence of divided attention on walking execution. However, motor planning was overestimated as compared with real walking.

  10. Normalized knee-extension strength or leg-press power after fast-track total knee arthroplasty

    DEFF Research Database (Denmark)

    Aalund, Peter K; Larsen, Kristian; Hansen, Torben Bæk

    2013-01-01

    OBJECTIVE: (s): To investigate which of the two muscle-impairment measures for the operated leg, normalized knee extension strength or leg press power, is more closely associated to performance-based and self-reported measures of function shortly following total knee arthroplasty (TKA). DESIGN...... and dynamic leg presses to determine their body-mass normalized knee extension strength and leg press power, respectively. The 10-m fast speed walking and 30-s chair stand tests were used to determine performance-based function, while the Western Ontario McMaster University Osteoarthritis Index (WOMAC......) and Oxford Knee scores were used to determine self-reported function. RESULTS: Normalized leg press power was more closely associated to both performance-based (r=.82, P...

  11. Is the impact of fatigue related to walking capacity and perceived ability in persons with multiple sclerosis? A multicenter study.

    Science.gov (United States)

    Dalgas, U; Langeskov-Christensen, M; Skjerbæk, A; Jensen, E; Baert, I; Romberg, A; Santoyo Medina, C; Gebara, B; Maertens de Noordhout, B; Knuts, K; Béthoux, F; Rasova, K; Severijns, D; Bibby, B M; Kalron, A; Norman, B; Van Geel, F; Wens, I; Feys, P

    2018-04-15

    The relationship between fatigue impact and walking capacity and perceived ability in patients with multiple sclerosis (MS) is inconclusive in the existing literature. A better understanding might guide new treatment avenues for fatigue and/or walking capacity in patients with MS. To investigate the relationship between the subjective impact of fatigue and objective walking capacity as well as subjective walking ability in MS patients. A cross-sectional multicenter study design was applied. Ambulatory MS patients (n = 189, age: 47.6 ± 10.5 years; gender: 115/74 women/men; Expanded Disability Status Scale (EDSS): 4.1 ± 1.8 [range: 0-6.5]) were tested at 11 sites. Objective tests of walking capacity included short walking tests (Timed 25-Foot Walk (T25FW), 10-Metre Walk Test (10mWT) at usual and fastest speed and the timed up and go (TUG)), and long walking tests (2- and 6-Minute Walk Tests (MWT). Subjective walking ability was tested applying the Multiple Sclerosis Walking Scale-12 (MSWS-12). Fatigue impact was measured by the self-reported modified fatigue impact scale (MFIS) consisting of a total score (MFIS total ) and three subscales (MFIS physical , MFIS cognitive and MFIS psychosocial ). Uni- and multivariate regression analysis were performed to evaluate the relation between walking and fatigue impact. MFIS total was negatively related with long (6MWT, r = -0.14, p = 0.05) and short composite (TUG, r = -0.22, p = 0.003) walking measures. MFIS physical showed a significant albeit weak relationship to walking speed in all walking capacity tests (r = -0.22 to -0.33, p < .0001), which persisted in the multivariate linear regression analysis. Subjective walking ability (MSWS-12) was related to MFIS total (r = 0.49, p < 0.0001), as well as to all other subscales of MFIS (r = 0.24-0.63, p < 0.001), showing stronger relationships than objective measures of walking. The physical impact of fatigue is weakly

  12. Determination of Ankle and Metatarsophalangeal Stiffness During Walking and Jogging.

    Science.gov (United States)

    Mager, Fabian; Richards, Jim; Hennies, Malika; Dötzel, Eugen; Chohan, Ambreen; Mbuli, Alex; Capanni, Felix

    2018-05-29

    Forefoot stiffness has been shown to influence joint biomechanics. However, little or no data exists on metatarsophalangeal stiffness. Twenty-four healthy rearfoot strike runners were recruited from a staff and student population at the University of Central Lancashire. Five repetitions of shod, self-selected speed level walking and jogging were performed. Kinetic and kinematic data were collected using retro-reflective markers placed on the lower limb and foot, to create a three-segment foot model using the Calibrated Anatomical System Technique. Ankle and metatarsophalangeal moments and angles were calculated. Stiffness values were calculated using a linear best fit line of moment versus of angle plots. Paired t-tests were used to compare values between walking and jogging conditions. Significant differences were seen in ankle range of motion (ROM), but not in metatarsophalangeal ROM. Maximum moments were significantly greater in the ankle during jogging, but these were not significantly different at the metatarsophalangeal joint. Average ankle joint stiffness exhibited significantly lower stiffness when walking compared to jogging. However, the metatarsophalangeal joint exhibited significantly greater stiffness when walking compared to jogging. A greater understanding of forefoot stiffness may inform the development of footwear, prosthetic feet and orthotic devices, such as ankle-foot orthoses for walking and sporting activities.

  13. High-speed scanning ablation of dental hard tissues with a λ = 9.3 μm CO2 laser: adhesion, mechanical strength, heat accumulation, and peripheral thermal damage

    OpenAIRE

    Nguyen, Daniel; Chang, Kwang; Hedayatollahnajafi, Saba; Staninec, Michal; Chan, Kenneth; Lee, Robert; Fried, Daniel

    2011-01-01

    CO2 lasers can be operated at high laser pulse repetition rates for the rapid and precise removal of dental decay. Excessive heat accumulation and peripheral thermal damage is a concern when using high pulse repetition rates. Peripheral thermal damage can adversely impact the mechanical strength of the irradiated tissue, particularly for dentin, and reduce the adhesion characteristics of the modified surfaces. The interpulpal temperature rise was recorded using microthermocouples situated at ...

  14. Effects of downhill walking training on aerobic and neuromuscular fitness of young adults

    Directory of Open Access Journals (Sweden)

    Leonardo Coelho Rabello de Lima

    2015-09-01

    Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2015v17n5p539   Eccentric exercise training using low intensity-high volume approach has been performed to improve maximal muscle strength and power. The aim of this study was to compare the effects of short-term downhill walking and level walking training on lower limb strength and maximal oxygen uptake of active individuals. Eighteen young adults were divided into level walking group (n = 9 or downhill walking training group (n = 9. Both groups performed a four-week training program. The level walking group performed seven level walking sessions per week, while the downhill walking group walked downhill (-16% in the same weekly frequency. One week before and one week after the training protocol, maximal oxygen uptake, muscle-bone cross-sectional area and isometric peak torque of knee extensors and plantar flexors were assessed for both groups. A significant group vs. time interaction was found only for cross sectional area of plantar flexors (PF, showing increases for the downhill walking group (112.6 ± 28.9 cm2 vs. 115.9 ± 29 cm2 but not for the level walking group (94.9 ± 23.3 cm2vs. 94.6 ± 228 cm2. Maximal oxygen uptake remained unaltered after training for both groups and IPT was increased after training for both groups. It was concluded that short-term downhill walking training does not seem to be efficient in promoting improvements in cardiorrespiratory fitness of young adults. However, it seems to promote gains in some variables related to neuromuscular fitness

  15. Cracking investigation of Monju emergency generator C unit cylinder liner. Cylinder liner soundness confirmation by a fall cause of the materials strength of the cylinder liner and the supersonic wave speed

    International Nuclear Information System (INIS)

    Kobayashi, Takanori; Sakon, Miyoji; Takada, Osamu; Hatori, Masakazu; Sakamoto, Tsutomu; Sato, Toshiyuki; Kazama, Akihito; Ishizawa, Yoshihiro; Igawa, Katsuhisa; Nakae, Hideo

    2012-02-01

    I confirmed a leak of the effluent gas from cylinder part during a load examination after the check of the emergency generator C unit on December 28, 2010 of the facilities check average and confirmed crack in No.8 cylinder liner part. As a result, because it was not performed oil pressure management properly without attaching an oil pressure gauge when I removed cylinder liner about the cause, crack occurred by having been able to write excessive stress for the cylinder liner and reached damage. By a process of this investigation, a fall of the materials strength of some cylinder liner was confirmed, but because a lead ingredient got mixed with materials by a casting process at the time of the production of the cylinder liner, as for this, Widmannstaetten graphite occurred, and it became clear that materials strength fell. In addition, I performed inspection by the supersonic wave velocity measurement as technique to distinguish this Widmannstaetten graphite easily and confirmed that I was effective. Because this report was the knowledge that there were little inspection contents which modified soundness confirmation technique of the cylinder liner with the possibility of materials strength fall of the cylinder liner by the Widmannstaetten graphite outbreak and the mixture of lead for a report example in the field of cast iron, I gathered it in this report. (author)

  16. The strength and conditioning practices of strongman competitors.

    Science.gov (United States)

    Winwood, Paul W; Keogh, Justin W L; Harris, Nigel K

    2011-11-01

    This study describes the results of a survey of the strength and conditioning practices of strongman competitors. A 65-item online survey was completed by 167 strongman competitors. The subject group included 83 local, 65 national, and 19 international strongman competitors. The survey comprised 3 main areas of enquiry: (a) exercise selection, (b) training protocols and organization, and (c) strongman event training. The back squat and conventional deadlift were reported as the most commonly used squat and deadlift (65.8 and 88.0%, respectively). Eighty percent of the subjects incorporated some form of periodization in their training. Seventy-four percent of subjects included hypertrophy training, 97% included maximal strength training, and 90% included power training in their training organization. The majority performed speed repetitions with submaximal loads in the squat and deadlift (59.9 and 61.1%, respectively). Fifty-four percent of subjects incorporated lower body plyometrics into their training, and 88% of the strongman competitors reported performing Olympic lifts as part of their strongman training. Seventy-eight percent of subjects reported that the clean was the most performed Olympic lift used in their training. Results revealed that 56 and 38% of the strongman competitors used elastic bands and chains in their training, respectively. The findings demonstrate that strongman competitors incorporate a variety of strength and conditioning practices that are focused on increasing muscular size, and the development of maximal strength and power into their conditioning preparation. The farmers walk, log press, and stones were the most commonly performed strongman exercises used in a general strongman training session by these athletes. These data provide information on the training practices required to compete in the sport of strongman.

  17. I Walk My Dog Because It Makes Me Happy: A Qualitative Study to Understand Why Dogs Motivate Walking and Improved Health

    Science.gov (United States)

    Marvin, Garry; Perkins, Elizabeth

    2017-01-01

    Dog walking is a popular everyday physical activity. Dog owners are generally more active than non-owners, but some rarely walk with their dog. The strength of the dog–owner relationship is known to be correlated with dog walking, and this qualitative study investigates why. Twenty-six interviews were combined with autoethnography of dog walking experiences. Dog walking was constructed as “for the dog”, however, owners represented their dog’s needs in a way which aligned with their own. Central to the construction of need was perceptions of dog personality and behaviour. Owners reported deriving positive outcomes from dog walking, most notably, feelings of “happiness”, but these were “contingent” on the perception that their dogs were enjoying the experience. Owner physical activity and social interaction were secondary bonuses but rarely motivating. Perceptions and beliefs of owners about dog walking were continually negotiated, depending on how the needs of the owner and dog were constructed at that time. Complex social interactions with the “significant other” of a pet can strongly motivate human health behaviour. Potential interventions to promote dog walking need to account for this complexity and the effect of the dog-owner relationship on owner mental wellbeing. PMID:28825614

  18. I Walk My Dog Because It Makes Me Happy: A Qualitative Study to Understand Why Dogs Motivate Walking and Improved Health.

    Science.gov (United States)

    Westgarth, Carri; Christley, Robert M; Marvin, Garry; Perkins, Elizabeth

    2017-08-19

    Dog walking is a popular everyday physical activity. Dog owners are generally more active than non-owners, but some rarely walk with their dog. The strength of the dog-owner relationship is known to be correlated with dog walking, and this qualitative study investigates why. Twenty-six interviews were combined with autoethnography of dog walking experiences. Dog walking was constructed as "for the dog", however, owners represented their dog's needs in a way which aligned with their own. Central to the construction of need was perceptions of dog personality and behaviour. Owners reported deriving positive outcomes from dog walking, most notably, feelings of "happiness", but these were "contingent" on the perception that their dogs were enjoying the experience. Owner physical activity and social interaction were secondary bonuses but rarely motivating. Perceptions and beliefs of owners about dog walking were continually negotiated, depending on how the needs of the owner and dog were constructed at that time. Complex social interactions with the "significant other" of a pet can strongly motivate human health behaviour. Potential interventions to promote dog walking need to account for this complexity and the effect of the dog-owner relationship on owner mental wellbeing.

  19. [Six-minute walk test in children with neuromuscular disease.

    Science.gov (United States)

    Cruz-Anleu, Israel Didier; Baños-Mejía, Benjamín Omar; Galicia-Amor, Susana

    2013-01-01

    Background: neuromuscular diseases affect the motor unit. When they evolve, respiratory complications are common; the six-minute walk test plays an important role in the assessment of functional capacity. Methods: prospective, transversal, descriptive and observational study. We studied seven children with a variety of neuromuscular diseases and spontaneous ambulation. We tested their lung function, and administered a six-minute walk test and a test of respiratory muscle strength to these children. Results: the age was 9.8 ± 2.4 years. All patients were males. Forced vital capacity decreased in three patients (42.8 %), forced expiratory volume during the first second (2.04 ± 1.4 L) and peak expiratory flow (4.33 ± 3.3 L/s) were normal. The maximum strength of respiratory muscles was less than 60 % of predicted values. The distance covered in the six-minute walk test was lower when compared with healthy controls (29.9 %). Conclusions: the six-minute walk test can be a useful tool in early stages of this disease, since it is easy to perform and well tolerated by the patients.

  20. A non-Lévy random walk in chacma baboons: what does it mean?

    Directory of Open Access Journals (Sweden)

    Cédric Sueur

    Full Text Available The Lévy walk is found from amoebas to humans and has been described as the optimal strategy for food research. Recent results, however, have generated controversy about this conclusion since animals also display alternatives to the Lévy walk such as the Brownian walk or mental maps and because movement patterns found in some species only seem to depend on food patches distribution. Here I show that movement patterns of chacma baboons do not follow a Lévy walk but a Brownian process. Moreover this Brownian walk is not the main process responsible for movement patterns of baboons. Findings about their speed and trajectories show that baboons use metal maps and memory to find resources. Thus the Brownian process found in this species appears to be more dependent on the environment or might be an alternative when known food patches are depleted and when animals have to find new resources.

  1. Power, speed & automation with Adobe Photoshop

    CERN Document Server

    Scott, Geoff

    2012-01-01

    This is a must for the serious Photoshop user! Power, Speed & Automation explores how to customize and automate Photoshop to increase your speed and productivity.  With numerous step-by-step instructions, the authors-two of Adobe's own software developers!- walk you through the steps to best tailor Photoshop's interface to your personal workflow; write and apply Actions; and use batching and scripts to process large numbers of images quickly and automatically.  You will learn how to build your own dialogs and panels to improve your production workflows in Photoshop, the secrets of changing

  2. Metabolic cost and mechanics of walking in women with fibromyalgia syndrome

    OpenAIRE

    MacPhee, Ren?e S; McFall, Kristen; Perry, Stephen D; Tiidus, Peter M

    2013-01-01

    Background Fibromyalgia syndrome (FS) is characterized by the presence of widespread pain, fatigue, muscle weakness and reduced work capacity. Previous research has demonstrated that women with fibromyalgia have altered walking (gait) patterns, which may be a consequence of muscular pain. This altered gait is characterized by greater reliance on hip flexors rather than ankle plantar flexors and resembles gait patterns seen in normal individuals walking at higher speeds, suggesting that gait o...

  3. Big power from walking

    Science.gov (United States)

    Illenberger, Patrin K.; Madawala, Udaya K.; Anderson, Iain A.

    2016-04-01

    Dielectric Elastomer Generators (DEG) offer an opportunity to capture the energy otherwise wasted from human motion. By integrating a DEG into the heel of standard footwear, it is possible to harness this energy to power portable devices. DEGs require substantial auxiliary systems which are commonly large, heavy and inefficient. A unique challenge for these low power generators is the combination of high voltage and low current. A void exists in the semiconductor market for devices that can meet these requirements. Until these become available, existing devices must be used in an innovative way to produce an effective DEG system. Existing systems such as the Bi-Directional Flyback (BDFB) and Self Priming Circuit (SPC) are an excellent example of this. The BDFB allows full charging and discharging of the DEG, improving power gained. The SPC allows fully passive voltage boosting, removing the priming source and simplifying the electronics. This paper outlines the drawbacks and benefits of active and passive electronic solutions for maximizing power from walking.

  4. The Dead Walk

    Directory of Open Access Journals (Sweden)

    Bill Phillips

    2014-02-01

    Full Text Available Monsters have always enjoyed a significant presence in the human imagination, and religion was instrumental in replacing the physical horror they engendered with that of a moral threat. Zombies, however, are amoral – their motivation purely instinctive and arbitrary, yet they are, perhaps, the most loathed of all contemporary monsters. One explanation for this lies in the theory of the uncanny valley, proposed by robotics engineer Masahiro Mori. According to the theory, we reserve our greatest fears for those things which seem most human, yet are not – such as dead bodies. Such a reaction is most likely a survival mechanism to protect us from danger and disease – a mechanism even more essential when the dead rise up and walk. From their beginnings zombies have reflected western societies’ greatest fears – be they of revolutionary Haitians, women, or communists. In recent years the rise in the popularity of the zombie in films, books and television series reflects our fears for the planet, the economy, and of death itself

  5. Effects of different frequencies of rhythmic auditory cueing on the stride length, cadence, and gait speed in healthy young females.

    Science.gov (United States)

    Yu, Lili; Zhang, Qi; Hu, Chunying; Huang, Qiuchen; Ye, Miao; Li, Desheng

    2015-02-01

    [Purpose] The aim of this study was to explore the effects of different frequencies of rhythmic auditory cueing (RAC) on stride length, cadence, and gait speed in healthy young females. The findings of this study might be used as clinical guidance of physical therapy for choosing the suitable frequency of RAC. [Subjects] Thirteen healthy young females were recruited in this study. [Methods] Ten meters walking tests were measured in all subjects under 4 conditions with each repeated 3 times and a 3-min seated rest period between repetitions. Subjects first walked as usual and then were asked to listen carefully to the rhythm of a metronome and walk with 3 kinds of RAC (90%, 100%, and 110% of the mean cadence). The three frequencies (90%, 100%, and 110%) of RAC were randomly assigned. Gait speed, stride length, and cadence were calculated, and a statistical analysis was performed using the SPSS (version 17.0) computer package. [Results] The gait speed and cadence of 90% RAC walking showed significant decreases compared with normal walking and 100% and 110% RAC walking. The stride length, cadence, and gait speed of 110% RAC walking showed significant increases compared with normal walking and 90% and 100% RAC walking. [Conclusion] Our results showed that 110% RAC was the best of the 3 cueing frequencies for improvement of stride length, cadence, and gait speed in healthy young females.

  6. Distinct sets of locomotor modules control the speed and modes of human locomotion

    Science.gov (United States)

    Yokoyama, Hikaru; Ogawa, Tetsuya; Kawashima, Noritaka; Shinya, Masahiro; Nakazawa, Kimitaka

    2016-01-01

    Although recent vertebrate studies have revealed that different spinal networks are recruited in locomotor mode- and speed-dependent manners, it is unknown whether humans share similar neural mechanisms. Here, we tested whether speed- and mode-dependence in the recruitment of human locomotor networks exists or not by statistically extracting locomotor networks. From electromyographic activity during walking and running over a wide speed range, locomotor modules generating basic patterns of muscle activities were extracted using non-negative matrix factorization. The results showed that the number of modules changed depending on the modes and speeds. Different combinations of modules were extracted during walking and running, and at different speeds even during the same locomotor mode. These results strongly suggest that, in humans, different spinal locomotor networks are recruited while walking and running, and even in the same locomotor mode different networks are probably recruited at different speeds. PMID:27805015

  7. Does hydrotherapy improve strength and physical function in patients with osteoarthritis—a randomised controlled trial comparing a gym based and a hydrotherapy based strengthening programme

    Science.gov (United States)

    Foley, A; Halbert, J; Hewitt, T; Crotty, M

    2003-01-01

    Objective: To compare the effects of a hydrotherapy resistance exercise programme with a gym based resistance exercise programme on strength and function in the treatment of osteoarthritis (OA). Design: Single blind, three arm, randomised controlled trial. Subjects: 105 community living participants aged 50 years and over with clinical OA of the hip or knee. Methods: Participants were randomised into one of three groups: hydrotherapy (n = 35), gym (n = 35), or control (n = 35). The two exercising groups had three exercise sessions a week for six weeks. At six weeks an independent physiotherapist unaware of the treatment allocation performed all outcome assessments (muscle strength dynamometry, six minute walk test, WOMAC OA Index, total drugs, SF-12 quality of life, Adelaide Activities Profile, and the Arthritis Self-Efficacy Scale). Results: In the gym group both left and right quadriceps significantly increased in strength compared with the control group, and right quadriceps strength was also significantly better than in the hydrotherapy group. The hydrotherapy group increased left quadriceps strength only at follow up, and this was significantly different from the control group. The hydrotherapy group was significantly different from the control group for distance walked and the physical component of the SF-12. The gym group was significantly different from the control group for walk speed and self efficacy satisfaction. Compliance rates were similar for both exercise groups, with 84% of hydrotherapy and 75% of gym sessions attended. There were no differences in drug use between groups over the study period. Conclusion: Functional gains were achieved with both exercise programmes compared with the control group. PMID:14644853

  8. Does hydrotherapy improve strength and physical function in patients with osteoarthritis--a randomised controlled trial comparing a gym based and a hydrotherapy based strengthening programme.

    Science.gov (United States)

    Foley, A; Halbert, J; Hewitt, T; Crotty, M

    2003-12-01

    To compare the effects of a hydrotherapy resistance exercise programme with a gym based resistance exercise programme on strength and function in the treatment of osteoarthritis (OA). Single blind, three arm, randomised controlled trial. 105 community living participants aged 50 years and over with clinical OA of the hip or knee. Participants were randomised into one of three groups: hydrotherapy (n = 35), gym (n = 35), or control (n = 35). The two exercising groups had three exercise sessions a week for six weeks. At six weeks an independent physiotherapist unaware of the treatment allocation performed all outcome assessments (muscle strength dynamometry, six minute walk test, WOMAC OA Index, total drugs, SF-12 quality of life, Adelaide Activities Profile, and the Arthritis Self-Efficacy Scale). In the gym group both left and right quadriceps significantly increased in strength compared with the control group, and right quadriceps strength was also significantly better than in the hydrotherapy group. The hydrotherapy group increased left quadriceps strength only at follow up, and this was significantly different from the control group. The hydrotherapy group was significantly different from the control group for distance walked and the physical component of the SF-12. The gym group was significantly different from the control group for walk speed and self efficacy satisfaction. Compliance rates were similar for both exercise groups, with 84% of hydrotherapy and 75% of gym sessions attended. There were no differences in drug use between groups over the study period. Functional gains were achieved with both exercise programmes compared with the control group.

  9. Walking around to grasp interaction

    DEFF Research Database (Denmark)

    Lykke, Marianne; Jantzen, Christian

    2013-01-01

    The paper presents experiences from a study using walk-alongs to provide insight into museum visitors’ experience with interactive features of sound art installations. The overall goal of the study was to learn about the participants’ opinions and feelings about the possibility of interaction...... with the sound installations. The aim was to gain an understanding of the role of the in-teraction, if interaction makes a difference for the understanding of the sound art. 30 walking interviews were carried out at ZKM, Karlsruhe with a total of 57 museum guests, individuals or groups. During the walk......-alongs the research-ers acted as facilitators and partners in the engagement with the sound installa-tions. The study provided good insight into advantages and challenges with the walk-along method, for instance the importance of shared, embodied sensing of space for the understanding of the experience. The common...

  10. Quantum snake walk on graphs

    International Nuclear Information System (INIS)

    Rosmanis, Ansis

    2011-01-01

    I introduce a continuous-time quantum walk on graphs called the quantum snake walk, the basis states of which are fixed-length paths (snakes) in the underlying graph. First, I analyze the quantum snake walk on the line, and I show that, even though most states stay localized throughout the evolution, there are specific states that most likely move on the line as wave packets with momentum inversely proportional to the length of the snake. Next, I discuss how an algorithm based on the quantum snake walk might potentially be able to solve an extended version of the glued trees problem, which asks to find a path connecting both roots of the glued trees graph. To the best of my knowledge, no efficient quantum algorithm solving this problem is known yet.

  11. High-speed resistance training is more effective than low-speed resistance training to increase functional capacity and muscle performance in older women.

    Science.gov (United States)

    Ramírez-Campillo, Rodrigo; Castillo, Angélica; de la Fuente, Carlos I; Campos-Jara, Christian; Andrade, David C; Álvarez, Cristian; Martínez, Cristian; Castro-Sepúlveda, Mauricio; Pereira, Ana; Marques, Mário C; Izquierdo, Mikel

    2014-10-01

    To examine the effects of 12 weeks of high-speed resistance training (RT) versus low-speed RT on muscle strength [one repetition of maximum leg-press (1RMLP) and bench-press (1RMBP), plus dominant (HGd) and non-dominant maximum isometric handgrip], power [counter-movement jump (CMJ), ball throwing (BT) and 10-m walking sprint (S10)], functional performance [8-foot up-and-go test (UG) and sit-to-stand test (STS)], and perceived quality of life in older women. 45 older women were divided into a high-speed RT group [EG, n=15, age=66.3±3.7y], a low-speed RT group [SG, n=15, age=68.7±6.4y] and a control group [CG, n=15, age=66.7±4.9y]. The SG and EG were submitted to a similar 12-week RT program [3 sets of 8 reps at 40-75% of the one-repetition maximum (1work per exercise without CMJ and BT). Over the 12-week training period, both RT groups showed small to large clinically significant improvements in the dependent variables; however, a significant difference was found between the EG and SG for the performance changes in BT, S10 and UG (20% vs. 11%, pperformance and quality of life in older women, although a high-speed RT program induces greater improvements in muscle power and functional capacity. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Hearing acuity as a predictor of walking difficulties in older women.

    Science.gov (United States)

    Viljanen, Anne; Kaprio, Jaakko; Pyykkö, Ilmari; Sorri, Martti; Koskenvuo, Markku; Rantanen, Taina

    2009-12-01

    To examine whether hearing acuity correlates with walking ability and whether impaired hearing at baseline predicts new self-reported walking difficulties after 3 years. Prospective follow-up. Research laboratory and community. Four hundred thirty-four women aged 63 to 76. Hearing was measured using clinical audiometry. A person was defined as having a hearing impairment if a pure-tone average of thresholds at 0.5 to 4 kHz in the better ear was 21 dB or greater. Maximal walking speed was measured over 10 m (m/s), walking endurance as the distance (m), covered in 6 minutes and difficulties in walking 2 km according to self-report. At baseline, women with hearing impairment (n=179) had slower maximal walking speed (1.7 +/- 0.3 m/s vs 1.8 +/- 0.3 m/s, P=.007), lower walking endurance (520 +/- 75 m vs 536 +/- 75 m, P=.08), and more selfreported major difficulties in walking 2 km (12.8% vs 5.5%, P=.02) than those without hearing impairment. During follow-up, major walking difficulties developed for 33 participants. Women with hearing impairment at baseline had a twice the age-adjusted risk for new walking difficulties as those without hearing impairment (odds ratio=2.04, 95% confidence interval=0.96-4.33). Hearing acuity correlated with mobility, which may be explained by the association between impaired hearing and poor balance and greater risk for falls, both of which underlie decline in mobility. Prevention of hearing loss is not only important for the ability to communicate, but may also have more wide-ranging influences on functional ability.

  13. Kinesthetic taping improves walking function in patients with stroke: a pilot cohort study.

    Science.gov (United States)

    Boeskov, Birgitte; Carver, Line Tornehøj; von Essen-Leise, Anders; Henriksen, Marius

    2014-01-01

    Stroke is an important cause of severe disability and impaired motor function. Treatment modalities that improve motor function in patients with stroke are needed. The objective of this study was to investigate the effect of kinesthetic taping of the anterior thigh and knee on maximal walking speed and clinical indices of spasticity in patients with stroke. Thirty-two patients (9 women) receiving rehabilitation after stroke (average, 50 days since stroke) who had impaired walking ability were recruited. Primary outcome was maximal walking speed measured by the 10-meter walk test. Secondary outcomes were number of steps taken during the test and clinical signs of spasticity measured by the Tardieu Scale. Tests were conducted before and immediately after application of kinesthetic tape to the anterior thigh and knee of the paretic lower limb. After application of the tape, the maximal walking speed increased, on average, by 0.08 m/s (95% CI, 0.04 to 0.12; P kinesthetic taping of the anterior thigh and knee provides an immediate improvement in walking function in patients with stroke. Such a positive effect on motor function could be a valuable adjunct in physical therapy and rehabilitation of patients with stroke.

  14. Influence of treadmill acceleration on actual walk-to-run transition.

    Science.gov (United States)

    Van Caekenberghe, I; Segers, V; De Smet, K; Aerts, P; De Clercq, D

    2010-01-01

    When accelerating continuously, humans spontaneously change from a walking to a running pattern by means of a walk-to-run transition (WRT). Results of previous studies indicate that when higher treadmill accelerations are imposed, higher WRT-speeds can be expected. By studying the kinematics of the WRT at different accelerations, the underlying mechanisms can be unravelled. 19 young, healthy female subjects performed walk-to-run transitions on a constantly accelerating treadmill (0.1, 0.2 and 0.5 m s(-2)). A higher acceleration induced a higher WRT-speed, by effecting the preparation of transition, as well as the actual transition step. Increasing the acceleration caused a higher WRT-speed as a result of a greater step length during the transition step, which was mainly a consequence of a prolonged airborne phase. Besides this effect on the transition step, the direct preparation phase of transition (i.e. the last walking step before transition) appeared to fulfil specific constraints required to execute the transition regardless of the acceleration imposed. This highlights an important role for this step in the debate regarding possible determinants of WRT. In addition spatiotemporal and kinematical data confirmed that WRT remains a discontinuous change of gait pattern in all accelerations imposed. It is concluded that the walk-to-run transition is a discontinuous switch from walking to running which depends on the magnitude of treadmill belt acceleration. Copyright 2009 Elsevier B.V. All rights reserved.

  15. The efficacy of the Ankle Mimicking Prosthetic Foot prototype 4.0 during walking: Physiological determinants.

    Science.gov (United States)

    De Pauw, Kevin; Cherelle, Pierre; Roelands, Bart; Lefeber, Dirk; Meeusen, Romain

    2018-04-01

    Evaluating the effectiveness of a novel prosthetic device during walking is an important step in product development. To investigate the efficacy of a novel quasi-passive ankle prosthetic device, Ankle Mimicking Prosthetic Foot 4.0, during walking at different speeds, using physiological determinants in transtibial and transfemoral amputees. Nonrandomized crossover design for amputees. Six able-bodied subjects, six unilateral transtibial amputees, and six unilateral transfemoral amputees underwent a 6-min walk test at normal speed, followed by series of 2-min walking at slow, normal, and fast speeds. The intensity of effort and subjective measures were determined. Amputees performed all walking tests on a treadmill with current and novel prostheses. Shapiro-Wilk normality tests and parametric and nonparametric tests were conducted (p 4.0 is a novel quasi-passive ankle prosthesis with state-of-the-art technological parts. Subjective measures show the importance of this technology, but the intensity of effort during walking still remains higher compared to current passive prostheses, especially in transfemoral amputees.

  16. Impaired Economy of Gait and Decreased Six-Minute Walk Distance in Parkinson's Disease

    Directory of Open Access Journals (Sweden)

    Leslie I. Katzel

    2012-01-01

    Full Text Available Changes in the biomechanics of gait may alter the energy requirements of walking in Parkinson's Disease (PD. This study investigated economy of gait during submaximal treadmill walking in 79 subjects with mild to moderate PD and the relationship between gait economy and 6-minute walk distance (6 MW. Oxygen consumption (VO2 at the self-selected treadmill walking speed averaged 64% of peak oxygen consumption (VO2 peak. Submaximal VO2 levels exceeded 70% of VO2 peak in 30% of the subjects. Overall the mean submaximal VO2 was 51% higher than VO2 levels expected for the speed and grade consistent with severe impairment in economy of gait. There was an inverse relationship between economy of gait and 6MW (r=−0.31, P<0.01 and with the self-selected walking speed (r=−0.35, P<0.01. Thus, the impairment in economy of gait and decreased physiologic reserve result in routine walking being performed at a high percentage of VO2 peak.

  17. Use of mobility aids reduces attentional demand in challenging walking conditions.

    Science.gov (United States)

    Miyasike-daSilva, Veronica; Tung, James Y; Zabukovec, Jeanie R; McIlroy, William E

    2013-02-01

    While mobility aids (e.g., four-wheeled walkers) are designed to facilitate walking and prevent falls in individuals with gait and balance impairments, there is evidence indicating that walkers may increase attentional demands during walking. We propose that walkers may reduce attentional demands under conditions that challenge balance control. This study investigated the effect of walker use on walking performance and attentional demand under a challenged walking condition. Young healthy subjects walked along a straight pathway, or a narrow beam. Attentional demand was assessed with a concurrent voice reaction time (RT) task. Slower RTs, reduced gait speed, and increased number of missteps (>92% of all missteps) were observed during beam-walking. However, walker use reduced attentional demand (faster RTs) and was linked to improved walking performance (increased gait speed, reduced missteps). Data from two healthy older adult cases reveal similar trends. In conclusion, mobility aids can be beneficial by reducing attentional demands and increasing gait stability when balance is challenged. This finding has implications on the potential benefit of mobility aids for persons who rely on walkers to address balance impairments. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. The influence of water depth on kinematic and spatiotemporal gait parameters during aquatic treadmill walking.

    Science.gov (United States)

    Jung, Taeyou; Kim, Yumi; Lim, Hyosok; Vrongistinos, Konstantinos

    2018-01-16

    The purpose of this study was to investigate kinematic and spatiotemporal variables of aquatic treadmill walking at three different water depths. A total of 15 healthy individuals completed three two-minute walking trials at three different water depths. The aquatic treadmill walking was conducted at waist-depth, chest-depth and neck-depth, while a customised 3-D underwater motion analysis system captured their walking. Each participant's self-selected walking speed at the waist level was used as a reference speed, which was applied to the remaining two test conditions. A repeated measures ANOVA showed statistically significant differences among the three walking conditions in stride length, cadence, peak hip extension, hip range of motion (ROM), peak ankle plantar flexion and ankle ROM (All p values hip ROM as the water depth rose from waist and chest to the neck level. However, our study found no significant difference between waist and chest level water in all variables. Hydrodynamics, such as buoyancy and drag force, in response to changes in water depths, can affect gait patterns during aquatic treadmill walking.

  19. Ground reaction forces during level ground walking with body weight unloading

    Science.gov (United States)

    Barela, Ana M. F.; de Freitas, Paulo B.; Celestino, Melissa L.; Camargo, Marcela R.; Barela, José A.

    2014-01-01

    Background: Partial body weight support (BWS) systems have been broadly used with treadmills as a strategy for gait training of individuals with gait impairments. Considering that we usually walk on level ground and that BWS is achieved by altering the load on the plantar surface of the foot, it would be important to investigate some ground reaction force (GRF) parameters in healthy individuals walking on level ground with BWS to better implement rehabilitation protocols for individuals with gait impairments. Objective: To describe the effects of body weight unloading on GRF parameters as healthy young adults walked with BWS on level ground. Method: Eighteen healthy young adults (27±4 years old) walked on a walkway, with two force plates embedded in the middle of it, wearing a harness connected to a BWS system, with 0%, 15%, and 30% BWS. Vertical and horizontal peaks and vertical valley of GRF, weight acceptance and push-off rates, and impulse were calculated and compared across the three experimental conditions. Results: Overall, participants walked more slowly with the BWS system on level ground compared to their normal walking speed. As body weight unloading increased, the magnitude of the GRF forces decreased. Conversely, weight acceptance rate was similar among conditions. Conclusions: Different amounts of body weight unloading promote different outputs of GRF parameters, even with the same mean walk speed. The only parameter that was similar among the three experimental conditions was the weight acceptance rate. PMID:25590450

  20. Ground reaction forces during level ground walking with body weight unloading

    Directory of Open Access Journals (Sweden)

    Ana M. F. Barela

    2014-12-01

    Full Text Available Background: Partial body weight support (BWS systems have been broadly used with treadmills as a strategy for gait training of individuals with gait impairments. Considering that we usually walk on level ground and that BWS is achieved by altering the load on the plantar surface of the foot, it would be important to investigate some ground reaction force (GRF parameters in healthy individuals walking on level ground with BWS to better implement rehabilitation protocols for individuals with gait impairments. Objective: To describe the effects of body weight unloading on GRF parameters as healthy young adults walked with BWS on level ground. Method: Eighteen healthy young adults (27±4 years old walked on a walkway, with two force plates embedded in the middle of it, wearing a harness connected to a BWS system, with 0%, 15%, and 30% BWS. Vertical and horizontal peaks and vertical valley of GRF, weight acceptance and push-off rates, and impulse were calculated and compared across the three experimental conditions. Results: Overall, participants walked more slowly with the BWS system on level ground compared to their normal walking speed. As body weight unloading increased, the magnitude of the GRF forces decreased. Conversely, weight acceptance rate was similar among conditions. Conclusions: Different amounts of body weight unloading promote different outputs of GRF parameters, even with the same mean walk speed. The only parameter that was similar among the three experimental conditions was the weight acceptance rate.

  1. Analysis of absorbing times of quantum walks

    International Nuclear Information System (INIS)

    Yamasaki, Tomohiro; Kobayashi, Hirotada; Imai, Hiroshi

    2003-01-01

    Quantum walks are expected to provide useful algorithmic tools for quantum computation. This paper introduces absorbing probability and time of quantum walks and gives both numerical simulation results and theoretical analyses on Hadamard walks on the line and symmetric walks on the hypercube from the viewpoint of absorbing probability and time

  2. Feasibility and Preliminary Efficacy of Visual Cue Training to Improve Adaptability of Walking after Stroke: Multi-Centre, Single-Blind Randomised Control Pilot Trial

    Science.gov (United States)

    Hollands, Kristen L.; Pelton, Trudy A.; Wimperis, Andrew; Whitham, Diane; Tan, Wei; Jowett, Sue; Sackley, Catherine M.; Wing, Alan M.; Tyson, Sarah F.; Mathias, Jonathan; Hensman, Marianne; van Vliet, Paulette M.

    2015-01-01

    Objectives Given the importance of vision in the control of walking and evidence indicating varied practice of walking improves mobility outcomes, this study sought to examine the feasibility and preliminary efficacy of varied walking practice in response to visual cues, for the rehabilitation of walking following stroke. Design This 3 arm parallel, multi-centre, assessor blind, randomised control trial was conducted within outpatient neurorehabilitation services Participants Community dwelling stroke survivors with walking speed adaptability practice using visual cues are feasible and may improve mobility and balance. Future studies should continue a carefully phased approach using identified methods to improve retention. Trial Registration Clinicaltrials.gov NCT01600391 PMID:26445137

  3. Random walk through fractal environments

    International Nuclear Information System (INIS)

    Isliker, H.; Vlahos, L.

    2003-01-01

    We analyze random walk through fractal environments, embedded in three-dimensional, permeable space. Particles travel freely and are scattered off into random directions when they hit the fractal. The statistical distribution of the flight increments (i.e., of the displacements between two consecutive hittings) is analytically derived from a common, practical definition of fractal dimension, and it turns out to approximate quite well a power-law in the case where the dimension D F of the fractal is less than 2, there is though, always a finite rate of unaffected escape. Random walks through fractal sets with D F ≤2 can thus be considered as defective Levy walks. The distribution of jump increments for D F >2 is decaying exponentially. The diffusive behavior of the random walk is analyzed in the frame of continuous time random walk, which we generalize to include the case of defective distributions of walk increments. It is shown that the particles undergo anomalous, enhanced diffusion for D F F >2 is normal for large times, enhanced though for small and intermediate times. In particular, it follows that fractals generated by a particular class of self-organized criticality models give rise to enhanced diffusion. The analytical results are illustrated by Monte Carlo simulations

  4. Inpatient rehabilitation improves functional capacity, peripheral muscle strength and quality of life in patients with community-acquired pneumonia: a randomised trial.

    Science.gov (United States)

    José, Anderson; Dal Corso, Simone

    2016-04-01

    Among people who are hospitalised for community-acquired pneumonia, does an inpatient exercise-based rehabilitation program improve functional outcomes, symptoms, quality of life and length of hospital stay more than a respiratory physiotherapy regimen? Randomised trial with concealed allocation, intention-to-treat analysis and blinding of some outcomes. Forty-nine adults hospitalised for community-acquired pneumonia. The experimental group (n=32) underwent a physical training program that included warm-up, stretching, peripheral muscle strength training and walking at a controlled speed for 15 minutes. The control group (n=17) underwent a respiratory physiotherapy regimen that included percussion, vibrocompression, respiratory exercises and free walking. The intervention regimens lasted 8 days. The primary outcome was the Glittre Activities of Daily Living test, which assesses the time taken to complete a series of functional tasks (eg, rising from a chair, walking, stairs, lifting and bending). Secondary outcomes were distance walked in the incremental shuttle walk test, peripheral muscle strength, quality of life, dyspnoea, lung function, C-reactive protein and length of hospital stay. Measures were taken 1 day before and 1 day after the intervention period. There was greater improvement in the experimental group than in the control group on the Glittre Activities of Daily Living test (mean between-group difference 39 seconds, 95% CI 20 to 59) and the incremental shuttle walk test (mean between-group difference 130 m, 95% CI 77 to 182). There were also significantly greater improvements in quality of life, dyspnoea and peripheral muscle strength in the experimental group than in the control group. There were no between-group differences in lung function, C-reactive protein or length of hospital stay. The improvement in functional outcomes after an inpatient rehabilitation program was greater than the improvement after standard respiratory physiotherapy. The

  5. The Need for Speed in Rodent Locomotion Analyses

    Science.gov (United States)

    Batka, Richard J.; Brown, Todd J.; Mcmillan, Kathryn P.; Meadows, Rena M.; Jones, Kathryn J.; Haulcomb, Melissa M.

    2016-01-01

    Locomotion analysis is now widely used across many animal species to understand the motor defects in disease, functional recovery following neural injury, and the effectiveness of various treatments. More recently, rodent locomotion analysis has become an increasingly popular method in a diverse range of research. Speed is an inseparable aspect of locomotion that is still not fully understood, and its effects are often not properly incorporated while analyzing data. In this hybrid manuscript, we accomplish three things: (1) review the interaction between speed and locomotion variables in rodent studies, (2) comprehensively analyze the relationship between speed and 162 locomotion variables in a group of 16 wild-type mice using the CatWalk gait analysis system, and (3) develop and test a statistical method in which locomotion variables are analyzed and reported in the context of speed. Notable results include the following: (1) over 90% of variables, reported by CatWalk, were dependent on speed with an average R2 value of 0.624, (2) most variables were related to speed in a nonlinear manner, (3) current methods of controlling for speed are insufficient, and (4) the linear mixed model is an appropriate and effective statistical method for locomotion analyses that is inclusive of speed-dependent relationships. Given the pervasive dependency of locomotion variables on speed, we maintain that valid conclusions from locomotion analyses cannot be made unless they are analyzed and reported within the context of speed. PMID:24890845

  6. Energy expenditure and physiological responses during walking on a treadmill and moving on the Torqway vehicle.

    Science.gov (United States)

    Maciejczyk, Marcin; Wiecek, Magdalena; Szymura, Jadwiga; Szygula, Zbigniew

    2016-01-01

    One of the new products which can be used to increase physical activity and energy expenditure is the Torqway vehicle, powered by the upper limbs. The aim of this study was to (1) assess the usefulness and repeatability of the Torqway vehicle for physical exercise, (2) compare energy expenditure and physiological responses during walking on a treadmill and during physical effort while moving on the Torqway at a constant speed. The participants (11 men, aged 20.2 ± 1.3) performed the incremental test and submaximal exercises (walking on the treadmill and moving on the Torqway vehicle at the same speed). Energy expenditure during the exercise on the Torqway was significantly higher (p = 0.001) than during the walking performed at the same speed. The intensity of the exercise performed on the Torqway expressed as %VO2max and %HRmax was significantly ( p walking (respectively: 35.0 ± 6.0 vs. 29.4 ± 7.4 %VO2max and 65.1 ± 7.3 vs. 47.2 ± 7.4 %HRmax). Exercise on the Torqway vehicle allows for the intensification of the exercise at a low movement speed, comparable to walking. Moving on the Torqway vehicle could be an effective alternative activity for physical fitness and exercise rehabilitation programs.

  7. Walking while performing working memory tasks changes the prefrontal cortex hemodynamic activations and gait kinematics

    Directory of Open Access Journals (Sweden)

    Ming-I Brandon Lin

    2016-05-01

    Full Text Available BackgroundIncreasing evidence suggests that walking while performing a concurrent task negatively influences gait performance. However, it remains unclear how higher-level cognitive processes and coordination of limb movements are altered in challenging walking environments. This study investigated the influence of cognitive task complexity and walking road condition on the neutral correlates of executive function and postural control in dual-task walking. MethodsTwenty-four healthy young adults completed a series of overground walks with three walking road conditions (wide, narrow, with obstacles with and without the concurrent n-back working memory tasks of two complexity levels (1-back and 3-back. Prefrontal brain activation was assessed by functional near-infrared spectroscopy. A three-dimensional motion analysis system was used simultaneously to measure gait performance and lower-extremity kinematics. Repeated measures analysis of variance were performed to examine the differences between the conditions. ResultsIn comparison with standing still, participants showed lower n-back task accuracy while walking, with the worst performance from the road with obstacles. Spatiotemporal gait parameters, lower-extremity joint movements, and the relative changes in oxygenated hemoglobin (HbO concentration levels were all significantly different across the task complexity and walking path conditions. While dual-tasking participants were found to flex their hips and knees less, leading to a slower gait speed, longer stride time, shorter step length, and greater gait variability than during normal walking. For narrow-road walking, smaller ankle dorsiflexion and larger hip flexion were observed, along with a reduced gait speed. Obstacle negotiation was mainly characterized by increased gait variability than other conditions. HbO levels appeared to be lower during dual-task walking than normal walking. Compared to wide and obstacle conditions, walking on

  8. FDG-PET imaging of lower extremity muscular activity during level walking

    International Nuclear Information System (INIS)

    Oi, Naoyuki; Iwaya, Tsutomu; Tobimatsu, Yoshiko; Fujimoto, Toshihiko; Itoh, Masatoshi; Yamaguchi, Keiichiro

    2003-01-01

    We analyzed muscular activity of the lower extremities during level walking using positron emission tomography (PET) with 18 F-fluorodeoxyglucose ( 18 F-FDG). We examined 17 healthy male subjects; 11 were assigned to a walking group and 6 to a resting group. After 18 F-FDG injection, the walking group subjects walked at a free speed for 15 min. A whole-body image was then obtained by a PET camera, and the standardized uptake ratio (SUR) was computed for each muscle. The SUR for each muscle of the walking group was compared with that for the corresponding muscles in the resting group. The level of muscular activity of all the muscles we examined were higher during level walking than when resting. The activity of the lower leg muscles was higher than that of the thigh muscles during level walking. The muscular activity of the soleus was highest among all the muscles examined. Among the gluteal muscles, the muscular activity of the gluteus minimus was higher than that of the gluteus maximus and gluteus medius. The concurrent validity of measuring muscular activity of the lower extremity during level walking by the PET method using 18 F-FDG was demonstrated. (author)

  9. ENGINEERING DESIGN OPTIMIZATION OF HEEL TESTING EQUIPMENT IN THE EXPERIMENTAL VALIDATION OF SAFE WALKING

    Directory of Open Access Journals (Sweden)

    Cristiano Fragassa

    2017-06-01

    Full Text Available Experimental test methods for the evaluation of the resistance of heels of ladies' shoes in the case of impact loads are fully defined by International Organization for Standardization (ISO procedures that indicate all the conditions of experiment. A first Standard (ISO 19553 specifies the test method for determining the strength of the heels in the case of single impact. The result offers a valuation of the liability to fail under the sporadic heavy blows. A second Standard (ISO 19556 details a method for testing the capability of heels of women' shoes to survive to the repetition of small impacts provoked by normal walking. These Standards strictly define the features for two different testing devices (with specific materials, geometries, weights, etc. and all the experimental procedures to be followed during tests. On the contrary, this paper describes the technical solutions adopted to design one single experimental device able to perform impact testing of heels in both conditions. Joining the accuracy of mechanic movements with the speed of an electronic control system, a new and flexible equipment for the complete characterization of heels respect to (single or fatigue impacts was developed. Moreover a new level of performances in experimental validation of heel resistance was introduced by the versatility of the user-defined software control programs, able to encode every complex time-depending cycle of impact loads. Dynamic simulations permitted to investigate the impacts on heel in different conditions of testing, optimizing the machine design. The complexity of real stresses on shoes during an ordinary walk and in other common situations (as going up and downstairs was considered for a proper dimensioning.

  10. Functional electrical stimulation of the ankle dorsiflexors during walking in spastic cerebral palsy: a systematic review.

    Science.gov (United States)

    Moll, Irene; Vles, Johannes S H; Soudant, Dan L H M; Witlox, Adhiambo M A; Staal, Heleen M; Speth, Lucianne A W M; Janssen-Potten, Yvonne J M; Coenen, Marcel; Koudijs, Suzanne M; Vermeulen, R Jeroen

    2017-12-01

    To assess the effect of functional electrical stimulation (FES) of ankle dorsiflexors in children and adolescents with spastic cerebral palsy (CP) during walking. A systematic review was performed using the American Academy of Cerebral Palsy and Developmental Medicine methodology and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Six databases were searched for studies applying interventions to patients aged younger than 20 years. Outcomes were classified according to the International Classification of Functioning, Disability and Health (ICF). Seven hundred and eighty abstracts were found, 35 articles were fully screened, and 14 articles were used for analysis. Only five articles (three studies) were of level I to III evidence. At ICF participation and activity level, there is limited evidence for a decrease in self-reported frequency of toe-drag and falls. At ICF body structure and function level, there is clear evidence (I-III) that FES increased (active) ankle dorsiflexion angle, strength, and improved selective motor control, balance, and gait kinematics, but decreased walking speed. Adverse events include skin irritation, toleration, and acceptation issues. There are insufficient data supporting functional gain by FES on activity and participation level. However, evidence points towards a role for FES as an alternative to orthoses in children with spastic CP. Effects of functional electrical stimulation (FES) point towards a potential role as an alternative to orthoses for patients with spastic cerebral palsy (CP). Some evidence for a decrease in self-reported frequency of toe-drag and falls with the use of FES in spastic CP. Limited evidence for improvements in activity and participation in patients with spastic CP using FES. © 2017 Mac Keith Press.

  11. Pedestrian Walking Behavior Revealed through a Random Walk Model

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    Hui Xiong

    2012-01-01

    Full Text Available This paper applies method of continuous-time random walks for pedestrian flow simulation. In the model, pedestrians can walk forward or backward and turn left or right if there is no block. Velocities of pedestrian flow moving forward or diffusing are dominated by coefficients. The waiting time preceding each jump is assumed to follow an exponential distribution. To solve the model, a second-order two-dimensional partial differential equation, a high-order compact scheme with the alternating direction implicit method, is employed. In the numerical experiments, the walking domain of the first one is two-dimensional with two entrances and one exit, and that of the second one is two-dimensional with one entrance and one exit. The flows in both scenarios are one way. Numerical results show that the model can be used for pedestrian flow simulation.

  12. The effect of uphill and downhill walking on gait parameters: A self-paced treadmill study.

    Science.gov (United States)

    Kimel-Naor, Shani; Gottlieb, Amihai; Plotnik, Meir

    2017-07-26

    It has been shown that gait parameters vary systematically with the slope of the surface when walking uphill (UH) or downhill (DH) (Andriacchi et al., 1977; Crowe et al., 1996; Kawamura et al., 1991; Kirtley et al., 1985; McIntosh et al., 2006; Sun et al., 1996). However, gait trials performed on inclined surfaces have been subject to certain technical limitations including using fixed speed treadmills (TMs) or, alternatively, sampling only a few gait cycles on inclined ramps. Further, prior work has not analyzed upper body kinematics. This study aims to investigate effects of slope on gait parameters using a self-paced TM (SPTM) which facilitates more natural walking, including measuring upper body kinematics and gait coordination parameters. Gait of 11 young healthy participants was sampled during walking in steady state speed. Measurements were made at slopes of +10°, 0° and -10°. Force plates and a motion capture system were used to reconstruct twenty spatiotemporal gait parameters. For validation, previously described parameters were compared with the literature, and novel parameters measuring upper body kinematics and bilateral gait coordination were also analyzed. Results showed that most lower and upper body gait parameters were affected by walking slope angle. Specifically, UH walking had a higher impact on gait kinematics than DH walking. However, gait coordination parameters were not affected by walking slope, suggesting that gait asymmetry, left-right coordination and gait variability are robust characteristics of walking. The findings of the study are discussed in reference to a potential combined effect of slope and gait speed. Follow-up studies are needed to explore the relative effects of each of these factors. Copyright © 2017. Published by Elsevier Ltd.

  13. Metabolic cost and mechanics of walking in women with fibromyalgia syndrome.

    Science.gov (United States)

    MacPhee, Renée S; McFall, Kristen; Perry, Stephen D; Tiidus, Peter M

    2013-10-18

    Fibromyalgia syndrome (FS) is characterized by the presence of widespread pain, fatigue, muscle weakness and reduced work capacity. Previous research has demonstrated that women with fibromyalgia have altered walking (gait) patterns, which may be a consequence of muscular pain. This altered gait is characterized by greater reliance on hip flexors rather than ankle plantar flexors and resembles gait patterns seen in normal individuals walking at higher speeds, suggesting that gait of individuals with fibromyalgia may be less efficient.This study compared rates of energy expenditure of 6 females with FS relative to 6 normal, age and weight matched controls, at various walking speeds on a motorized treadmill. Metabolic measurements including V02 (ml/kg/min), respirations, heart rate and calculated energy expenditures as well as the Borg Scale of Perceived Exertion scale ratings were determined at baseline and for 10 min while walking at each of 2, 4 and 5 km/hour on 1% grade. Kinematic recordings of limb and body movements while treadmill walking and separate measurements of ground reaction forces while walking over ground were also determined. In addition, all subjects completed the RAND 36-Item Health Survey (1.0). Gait analysis results were similar to previous reports of altered gait patterns in FS females. Despite noticeable differences in gait patterns, no significant differences (p > 0.05) existed between the FS and control subjects on any metabolic measures at any walking speed. Total number of steps taken was also similar between groups. Ratings on the Borg Scale of Perceived Exertion, the RAND and self-reported levels of pain indicated significantly greater (p gait patterns and greater perceptions of effort and pain did not significantly increase the metabolic costs of walking in women with FS and hence, increased sensations of fatigue in FS women may not be related to alteration in metabolic cost of ambulation.

  14. Testosterone Replacement, Muscle Strength, and Physical Function

    Directory of Open Access Journals (Sweden)

    You-Seon Nam

    2018-05-01

    Full Text Available Muscle strength and physical function decrease in older men, as do testosterone levels. Nonetheless, the effects of testosterone replacement therapy on muscle strength and physical function remain inconclusive and equivocal. We conducted a rapid systematic review, the results of which showed that testosterone replacement does not affect muscle strength (measured by hand grip strength and leg muscle strength, although it may increase physical function (measured by the 6-minute walk test, Physical Activity Scale for the Elderly score, and other physical performance tests. However, most of the studies were conducted in the United States or Europe and did not include participants from Asian or other ethnic backgrounds; therefore, further studies are needed to evaluate the effects of testosterone replacement in a broader population.

  15. Mechanical design of walking machines.

    Science.gov (United States)

    Arikawa, Keisuke; Hirose, Shigeo

    2007-01-15

    The performance of existing actuators, such as electric motors, is very limited, be it power-weight ratio or energy efficiency. In this paper, we discuss the method to design a practical walking machine under this severe constraint with focus on two concepts, the gravitationally decoupled actuation (GDA) and the coupled drive. The GDA decouples the driving system against the gravitational field to suppress generation of negative power and improve energy efficiency. On the other hand, the coupled drive couples the driving system to distribute the output power equally among actuators and maximize the utilization of installed actuator power. First, we depict the GDA and coupled drive in detail. Then, we present actual machines, TITAN-III and VIII, quadruped walking machines designed on the basis of the GDA, and NINJA-I and II, quadruped wall walking machines designed on the basis of the coupled drive. Finally, we discuss walking machines that travel on three-dimensional terrain (3D terrain), which includes the ground, walls and ceiling. Then, we demonstrate with computer simulation that we can selectively leverage GDA and coupled drive by walking posture control.

  16. Differences in foot kinematics between young and older adults during walking.

    Science.gov (United States)

    Arnold, John B; Mackintosh, Shylie; Jones, Sara; Thewlis, Dominic

    2014-02-01

    Our understanding of age-related changes to foot function during walking has mainly been based on plantar pressure measurements, with little information on differences in foot kinematics between young and older adults. The purpose of this study was to investigate the differences in foot kinematics between young and older adults during walking using a multi-segment foot model. Joint kinematics of the foot and ankle for 20 young (mean age 23.2 years, standard deviation (SD) 3.0) and 20 older adults (mean age 73.2 years, SD 5.1) were quantified during walking with a 12 camera Vicon motion analysis system using a five segment kinematic model. Differences in kinematics were compared between older adults and young adults (preferred and slow walking speeds) using Student's t-tests or if indicated, Mann-Whitney U tests. Effect sizes (Cohen's d) for the differences were also computed. The older adults had a less plantarflexed calcaneus at toe-off (-9.6° vs. -16.1°, d = 1.0, p = range of motion (ROM) of the midfoot (11.9° vs. 14.8°, d = 1.3, p = young adults. Walking speed did not influence these differences, as they remained present when groups walked at comparable speeds. The findings of this study indicate that independent of walking speed, older adults exhibit significant differences in foot kinematics compared to younger adults, characterised by less propulsion and reduced mobility of multiple foot segments. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Within-day variability on short and long walking tests in persons with multiple sclerosis.

    Science.gov (United States)

    Feys, Peter; Bibby, Bo; Romberg, Anders; Santoyo, Carme; Gebara, Benoit; de Noordhout, Benoit Maertens; Knuts, Kathy; Bethoux, Francois; Skjerbæk, Anders; Jensen, Ellen; Baert, Ilse; Vaney, Claude; de Groot, Vincent; Dalgas, Ulrik

    2014-03-15

    To compare within-day variability of short (10 m walking test at usual and fastest speed; 10MWT) and long (2 and 6-minute walking test; 2MWT/6MWT) tests in persons with multiple sclerosis. Observational study. MS rehabilitation and research centers in Europe and US within RIMS (European network for best practice and research in MS rehabilitation). Ambulatory persons with MS (Expanded Disability Status Scale 0-6.5). Subjects of different centers performed walking tests at 3 time points during a single day. 10MWT, 2MWT and 6MWT at fastest speed and 10MWT at usual speed. Ninety-five percent limits of agreement were computed using a random effects model with individual pwMS as random effect. Following this model, retest scores are with 95% certainty within these limits of baseline scores. In 102 subjects, within-day variability was constant in absolute units for the 10MWT, 2MWT and 6MWT at fastest speed (+/-0.26, 0.16 and 0.15m/s respectively, corresponding to +/-19.2m and +/-54 m for the 2MWT and 6MWT) independent on the severity of ambulatory dysfunction. This implies a greater relative variability with increasing disability level, often above 20% depending on the applied test. The relative within-day variability of the 10MWT at usual speed was +/-31% independent of ambulatory function. Absolute values of within-day variability on walking tests at fastest speed were independent of disability level and greater with short compared to long walking tests. Relative within-day variability remained overall constant when measured at usual speed. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

  18. Quantum walks based on an interferometric analogy

    International Nuclear Information System (INIS)

    Hillery, Mark; Bergou, Janos; Feldman, Edgar

    2003-01-01

    There are presently two models for quantum walks on graphs. The ''coined'' walk uses discrete-time steps, and contains, besides the particle making the walk, a second quantum system, the coin, that determines the direction in which the particle will move. The continuous walk operates with continuous time. Here a third model for quantum walks is proposed, which is based on an analogy to optical interferometers. It is a discrete-time model, and the unitary operator that advances the walk one step depends only on the local structure of the graph on which the walk is taking place. This type of walk also allows us to introduce elements, such as phase shifters, that have no counterpart in classical random walks. Several examples are discussed

  19. Shoe-Insole Technology for Injury Prevention in Walking

    Directory of Open Access Journals (Sweden)

    Hanatsu Nagano

    2018-05-01

    Full Text Available Impaired walking increases injury risk during locomotion, including falls-related acute injuries and overuse damage to lower limb joints. Gait impairments seriously restrict voluntary, habitual engagement in injury prevention activities, such as recreational walking and exercise. There is, therefore, an urgent need for technology-based interventions for gait disorders that are cost effective, willingly taken-up, and provide immediate positive effects on walking. Gait control using shoe-insoles has potential as an effective population-based intervention, and new sensor technologies will enhance the effectiveness of these devices. Shoe-insole modifications include: (i ankle joint support for falls prevention; (ii shock absorption by utilising lower-resilience materials at the heel; (iii improving reaction speed by stimulating cutaneous receptors; and (iv preserving dynamic balance via foot centre of pressure control. Using sensor technology, such as in-shoe pressure measurement and motion capture systems, gait can be precisely monitored, allowing us to visualise how shoe-insoles change walking patterns. In addition, in-shoe systems, such as pressure monitoring and inertial sensors, can be incorporated into the insole to monitor gait in real-time. Inertial sensors coupled with in-shoe foot pressure sensors and global positioning systems (GPS could be used to monitor spatiotemporal parameters in real-time. Real-time, online data management will enable ‘big-data’ applications to everyday gait control characteristics.

  20. Understanding the Demographic Differences in Neighborhood Walking Supports.

    Science.gov (United States)

    Carlson, Susan A; Watson, Kathleen B; Paul, Prabasaj; Schmid, Thomas L; Fulton, Janet E

    2017-04-01

    Information about how presence and usefulness of neighborhood supports for walking differs by demographic characteristics can help guide community strategies to promote walking. Reported presence and usefulness of neighborhood supports (shops, transit stops, sidewalks, parks, interesting things to look at, well-lit at night, low crime rate, and cars following speed limit) were examined in 3973 U.S. adults who completed the 2014 SummerStyles survey. Percentage reporting neighborhood supports as present ranged from 25.3% (SE = 0.8) for interesting things to 55.8% (SE = 1.0) for low crime rate. Percentage who reported a support as useful ranged from 24.6% (SE = 1.4) for transit stops to 79.0% (SE = 1.1) for sidewalks among those with the support. This percentage ranged from 13.4% (SE = 0.8) for transit stops to 52.8% (SE = 1.1) for shops among those without the support. One or more demographic differences were observed for the presence of each support, and the presence of all supports differed by education and metro status. Demographic patterns were less clear when examining usefulness and patterns often differed by support type and presence. Presence and usefulness of neighborhood supports for walking can differ by type and demographic characteristics. Recognizing these difference can help communities plan and implement strategies to promote walking.

  1. Required friction during overground walking is lower among obese compared to non-obese older men, but does not differ with obesity among women.

    Science.gov (United States)

    Arena, Sara L; Garman, Christina R; Nussbaum, Maury A; Madigan, Michael L

    2017-07-01

    Obesity and aging have been independently associated with altered required friction during walking, but it is unclear how these factors interact to influence the likelihood of slipping. Therefore, the purpose of this study was to determine whether there are differences related to obesity and aging on required friction during overground walking. Fourteen older non-obese, 11 older obese, 20 younger non-obese, and 20 younger obese adults completed walking trials at both a self-selected and hurried speed. When walking at a hurried speed, older obese men walked at a slower gait speed and exhibited lower frictional demands compared both to older non-obese men and to younger obese men. No differences in required friction were found between non-obese and obese younger adults. These results suggest that the increased rate of falls among obese or older adults is not likely due to a higher risk of slip initiation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Gait characteristics under different walking conditions: Association with the presence of cognitive impairment in community-dwelling older people.

    Directory of Open Access Journals (Sweden)

    Anne-Marie De Cock

    Full Text Available Gait characteristics measured at usual pace may allow profiling in patients with cognitive problems. The influence of age, gender, leg length, modified speed or dual tasking is unclear.Cross-sectional analysis was performed on a data registry containing demographic, physical and spatial-temporal gait parameters recorded in five walking conditions with a GAITRite® electronic carpet in community-dwelling older persons with memory complaints. Four cognitive stages were studied: cognitively healthy individuals, mild cognitive impaired patients, mild dementia patients and advanced dementia patients.The association between spatial-temporal gait characteristics and cognitive stages was the most prominent: in the entire study population using gait speed, steps per meter (translation for mean step length, swing time variability, normalised gait speed (corrected for leg length and normalised steps per meter at all five walking conditions; in the 50-to-70 years old participants applying step width at fast pace and steps per meter at usual pace; in the 70-to-80 years old persons using gait speed and normalised gait speed at usual pace, fast pace, animal walk and counting walk or steps per meter and normalised steps per meter at all five walking conditions; in over-80 years old participants using gait speed, normalised gait speed, steps per meter and normalised steps per meter at fast pace and animal dual-task walking. Multivariable logistic regression analysis adjusted for gender predicted in two compiled models the presence of dementia or cognitive impairment with acceptable accuracy in persons with memory complaints.Gait parameters in multiple walking conditions adjusted for age, gender and leg length showed a significant association with cognitive impairment. This study suggested that multifactorial gait analysis could be more informative than using gait analysis with only one test or one variable. Using this type of gait analysis in clinical practice

  3. Who walks? Factors associated with walking behavior in disabled older women with and without self-reported walking difficulty.

    Science.gov (United States)

    Simonsick, E M; Guralnik, J M; Fried, L P

    1999-06-01

    To determine how severity of walking difficulty and sociodemographic, psychosocial, and health-related factors influence walking behavior in disabled older women. Cross-sectional analyses of baseline data from the Women's Health and Aging Study (WHAS). An urban community encompassing 12 contiguous zip code areas in the eastern portion of Baltimore City and part of Baltimore County, Maryland. A total of 920 moderately to severely disabled community-resident women, aged 65 years and older, identified from an age-stratified random sample of Medicare beneficiaries. Walking behavior was defined as minutes walked for exercise and total blocks walked per week. Independent variables included self-reported walking difficulty, sociodemographic factors, psychological status (depression, mastery, anxiety, and cognition), and health-related factors (falls and fear of falling, fatigue, vision and balance problems, weight, smoking, and cane use). Walking at least 8 blocks per week was strongly negatively related to severity of walking difficulty. Independent of difficulty level, older age, black race, fatigue, obesity, and cane use were also negatively associated with walking; living alone and high mastery had a positive association with walking. Even among functionally limited women, sociocultural, psychological, and health-related factors were independently associated with walking behavior. Thus, programs aimed at improving walking ability need to address these factors in addition to walking difficulties to maximize participation and compliance.

  4. Single and Dual Task Walking

    Directory of Open Access Journals (Sweden)

    Natalie de Bruin

    2010-01-01

    Full Text Available This study explored the viability and efficacy of integrating cadence-matched, salient music into a walking intervention for patients with Parkinson's disease (PD. Twenty-two people with PD were randomised to a control (CTRL, n=11 or experimental (MUSIC, n=11 group. MUSIC subjects walked with an individualised music playlist three times a week for the intervention period. Playlists were designed to meet subject's musical preferences. In addition, the tempo of the music closely matched (±10–15 bpm the subject's preferred cadence. CTRL subjects continued with their regular activities during the intervention. The effects of training accompanied by “walking songs” were evaluated using objective measures of gait score. The MUSIC group improved gait velocity, stride time, cadence, and motor symptom severity following the intervention. This is the first study to demonstrate that music listening can be safely implemented amongst PD patients during home exercise.

  5. Walking the history of healthcare.

    Science.gov (United States)

    Black, Nick

    2007-12-01

    The history of healthcare is complex, confusing and contested. In Walking London's medical history the story of how health services developed from medieval times to the present day is told through seven walks. The book also aims to help preserve our legacy, as increasingly former healthcare buildings are converted to other uses, an