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Sample records for knee adduction moment

  1. The knee adduction moment measured with an instrumented force shoe in patients with knee osteoarthritis

    NARCIS (Netherlands)

    van den Noort, J.C.; van den Noort, Josien C.; van der Esch, Martin; Steultjens, Martijn P.M.; Dekker, Joost; Schepers, H. Martin; Veltink, Petrus H.; Harlaar, Jaap

    2012-01-01

    The external knee adduction moment (KAdM) during gait is an important parameter in patients with knee osteoarthritis (OA). KAdM measurement is currently restricted to instruments only available in gait laboratories. However, ambulatory movement analysis technology, including instrumented force shoes

  2. Real-Time Tracking of Knee Adduction Moment in Patients with Knee Osteoarthritis

    Science.gov (United States)

    Kang, Sang Hoon; Lee, Song Joo; Zhang, Li-Qun

    2014-01-01

    Background The external knee adduction moment (EKAM) is closely associated with the presence, progression, and severity of knee osteoarthritis (OA). However, there is a lack of convenient and practical method to estimate and track in real-time the EKAM of patients with knee OA for clinical evaluation and gait training, especially outside of gait laboratories. New Method A real-time EKAM estimation method was developed and applied to track and investigate the EKAM and other knee moments during stepping on an elliptical trainer in both healthy subjects and a patient with knee OA. Results Substantial changes were observed in the EKAM and other knee moments during stepping in the patient with knee OA. Comparison with Existing Method(s) This is the first study to develop and test feasibility of real-time tracking method of the EKAM on patients with knee OA using 3-D inverse dynamics. Conclusions The study provides us an accurate and practical method to evaluate in real-time the critical EKAM associated with knee OA, which is expected to help us to diagnose and evaluate patients with knee OA and provide the patients with real-time EKAM feedback rehabilitation training. PMID:24361759

  3. Gender differences in the knee adduction moment after anterior cruciate ligament reconstruction surgery.

    Science.gov (United States)

    Webster, Kate E; McClelland, Jodie A; Palazzolo, Simon E; Santamaria, Luke J; Feller, Julian A

    2012-04-01

    The external knee adduction moment during gait has previously been associated with knee pain and osteoarthritis (OA). Recently, the knee adduction moment has been shown to be increased following anterior cruciate ligament (ACL) reconstruction surgery and has been suggested as a potential mechanism for the progression of early onset knee OA in this population. No study has investigated the gender differences in gait biomechanics following ACL reconstruction. To examine gender differences in gait biomechanics following ACL reconstruction surgery. 36 subjects (18 females, 18 males) who had previously undergone ACL reconstruction surgery (mean time since surgery 20 months) underwent gait analysis at a self-selected walking speed. Males and females were well matched for age, time since surgery and walking speed. Maximum flexion and adduction angles and moments were recorded during the stance phase of level walking and compared between the male and female groups. The knee adduction moment was 23% greater in the female compared with the male ACL group. No gender differences were seen in the sagittal plane. No differences were seen between the reconstructed and contralateral limb. The higher knee adduction moment seen in females compared with males may suggest an increased risk for the development of OA in ACL-reconstructed females.

  4. Knee adduction moment and medial contact force--facts about their correlation during gait.

    Directory of Open Access Journals (Sweden)

    Ines Kutzner

    Full Text Available The external knee adduction moment is considered a surrogate measure for the medial tibiofemoral contact force and is commonly used to quantify the load reducing effect of orthopedic interventions. However, only limited and controversial data exist about the correlation between adduction moment and medial force. The objective of this study was to examine whether the adduction moment is indeed a strong predictor for the medial force by determining their correlation during gait. Instrumented knee implants with telemetric data transmission were used to measure tibiofemoral contact forces in nine subjects. Gait analyses were performed simultaneously to the joint load measurements. Skeletal kinematics, as well as the ground reaction forces and inertial parameters, were used as inputs in an inverse dynamics approach to calculate the external knee adduction moment. Linear regression analysis was used to analyze the correlation between adduction moment and medial force for the whole stance phase and separately for the early and late stance phase. Whereas only moderate correlations between adduction moment and medial force were observed throughout the whole stance phase (R(2 = 0.56 and during the late stance phase (R(2 = 0.51, a high correlation was observed at the early stance phase (R(2 = 0.76. Furthermore, the adduction moment was highly correlated to the medial force ratio throughout the whole stance phase (R(2 = 0.75. These results suggest that the adduction moment is a surrogate measure, well-suited to predicting the medial force ratio throughout the whole stance phase or medial force during the early stance phase. However, particularly during the late stance phase, moderate correlations and high inter-individual variations revealed that the predictive value of the adduction moment is limited. Further analyses are necessary to examine whether a combination of other kinematic, kinetic or neuromuscular factors may lead to a more

  5. Modelling knee flexion effects on joint power absorption and adduction moment.

    Science.gov (United States)

    Nagano, Hanatsu; Tatsumi, Ichiroh; Sarashina, Eri; Sparrow, W A; Begg, Rezaul K

    2015-12-01

    Knee osteoarthritis is commonly associated with ageing and long-term walking. In this study the effects of flexing motions on knee kinetics during stance were simulated. Extended knees do not facilitate efficient loading. It was therefore, hypothesised that knee flexion would promote power absorption and negative work, while possibly reducing knee adduction moment. Three-dimensional (3D) position and ground reaction forces were collected from the right lower limb stance phase of one healthy young male subject. 3D position was sampled at 100 Hz using three Optotrak Certus (Northern Digital Inc.) motion analysis camera units, set up around an eight metre walkway. Force plates (AMTI) recorded ground reaction forces for inverse dynamics calculations. The Visual 3D (C-motion) 'Landmark' function was used to change knee joint positions to simulate three knee flexion angles during static standing. Effects of the flexion angles on joint kinetics during the stance phase were then modelled. The static modelling showed that each 2.7° increment in knee flexion angle produced 2.74°-2.76° increments in knee flexion during stance. Increased peak extension moment was 6.61 Nm per 2.7° of increased knee flexion. Knee flexion enhanced peak power absorption and negative work, while decreasing adduction moment. Excessive knee extension impairs quadriceps' power absorption and reduces eccentric muscle activity, potentially leading to knee osteoarthritis. A more flexed knee is accompanied by reduced adduction moment. Research is required to determine the optimum knee flexion to prevent further damage to knee-joint structures affected by osteoarthritis. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. VIDEO-ANALYSIS OF THE EFFECT OF DIFFERENT TYPES OF ADAPTED SHOES ON KNEE ADDUCTION MOMENT

    Directory of Open Access Journals (Sweden)

    Andrey Yu. Aksenov

    2017-03-01

    Full Text Available Background. The effect of different footwear profiles on knee adduction moment have not been fully studied. Methods. Fifteen healthy volunteer subjects, age 25.3 (±2.73, undertook a series of gait laboratory trials with adapted shoes. Kinematic and kinetic data were collect using 16 Oqus 3+ cameras and the walking speed was controlled using timing gates. High street shoes were adapted to include five different heel heights (varying from a 1.5 cm to 5.5 cm heels, two heel profile conditions (curved and semi-curved heels, three varying apex angles (10, 15, and 20 degrees, and barefoot and 3CR footwear conditions. The baseline shoe had no heel curve, a heel height of 3.5cm, an apex position of 62.5% of the shoe length, an apex angle of 15 deg, and a rigid forepart of the shoe. Results. The shoe with 5.5 cm heel height significantly increased the mean knee adduction moment during 50%–100% of the stance phase compared to the 1.5 cm heel (p = 0.008. The high heel shoe also significantly increased knee adduction impulse (area under the curve versus the 1.5, 2.5, and 3.5 cm heels, and the 10° toe angle and barefoot condition. Ten degrees of toe angle reduced mean knee adduction moment during 0%–50% of the stance phase versus 20° and significantly reduced mean knee adduction moment during the late stance phase versus 15° and 20° toe angle footwear conditions. Walking with the curved heel for the healthy subjects increased mean knee adduction moment during 0%–50% of the stance phase compared to the heel without curvature (p < 0.0009. Conclusion. Further study is required to investigate those changes in patients with high risk of knee osteoarthritis.

  7. The association between submaximal quadriceps force steadiness and the knee adduction moment during walking in patients with knee osteoarthritis

    DEFF Research Database (Denmark)

    Sørensen, Tina Juul; Langberg, Henning; Aaboe, Jens

    2011-01-01

    in this population. METHODS: Forty-one patients with knee OA (34 females and 7 males) were included in the study. Submaximal isometric quadriceps force steadiness was measured during a force target-tracking task. Peak knee adduction moments during ambulation were measured using a 3-dimensional gait analysis system...

  8. Courses of change in knee adduction moment and lateral thrust differ up to 1 year after TKA.

    Science.gov (United States)

    Shimada, Noboru; Deie, Masataka; Hirata, Kazuhiko; Hiate, Yasuhiko; Orita, Naoya; Iwaki, Daisuke; Ito, Yoshihiro; Kimura, Hiroaki; Pappas, Evangelos; Ochi, Mitsuo

    2016-08-01

    In total knee arthroplasty (TKA), dynamic knee loading may loosen the artificial joint and bone or cause polyethylene wear after prolonged use. TKA decreases knee adduction moment at 6 months, but this effect is lost by 1 year post-operatively. However, lateral thrust after TKA has not been clarified. We hypothesized that like knee adduction moment, lateral thrust would return to baseline levels by 1 year post-operatively. Participants were 15 patients who underwent TKA for medial knee OA. Japanese Orthopaedic Association (JOA) score, numeric rating scale, and gait analysis (measurement of peak knee adduction moment, knee varus angle at peak knee adduction moment, lateral thrust, and gait speed) were performed preoperatively (baseline) and 3 weeks, 3 and 6 months, and 1 year post-operatively. JOA score improved from 55 ± 9.8 to 78 ± 12.1 at 1 year post-operatively, and pain decreased significantly from baseline at each follow-up (p < 0.001). Significant increases in gait speed were observed at 6 months and 1 year (p < 0.001). Peak knee adduction moment during stance phase was significantly lower at 3 weeks, 3 months, and 6 months compared to baseline (p < 0.05), but no significant changes were seen at 1 year. Knee varus at peak knee adduction moment did not differ significantly between any measurement points, while lateral thrust was decreased at 6 months and 1 year compared to baseline (p < 0.05). Temporal courses of changes up to 1 year after TKA differed between knee adduction moment and lateral thrust, so our hypothesis was rejected. IV.

  9. Real-time knee adduction moment feedback training using an elliptical trainer.

    Science.gov (United States)

    Kang, Sang Hoon; Lee, Song Joo; Ren, Yupeng; Zhang, Li-Qun

    2014-03-01

    The external knee adduction moment (EKAM) is associated with knee osteoarthritis (OA) in many aspects including presence, progression, and severity of knee OA. Despite of its importance, there is a lack of EKAM estimation methods that can provide patients with knee OA real-time EKAM biofeedback for training and clinical evaluations without using a motion analysis laboratory. A practical real-time EKAM estimation method, which utilizes kinematics measured by a simple six degree-of-freedom goniometer and kinetics measured by a multi-axis force sensor underneath the foot, was developed to provide real-time feedback of the EKAM to the patients during stepping on an elliptical trainer, which can potentially be used to control and alter the EKAM. High reliability (ICC(2,1): 0.9580) of the real-time EKAM estimation method was verified through stepping trials of seven subjects without musculoskeletal disorders. Combined with advantages of elliptical trainers including functional weight-bearing stepping and mitigation of impulsive forces, the real-time EKAM estimation method is expected to help patients with knee OA better control frontal plane knee loading and reduce knee OA development and progression.

  10. Effects of Lateral Heel Wedges and Lateral Forefoot Wedge on the Knee Adduction Moment in Healthy Male Students

    Directory of Open Access Journals (Sweden)

    Fatemeh Shamsi

    2012-01-01

    Full Text Available Objective: Lateral wedged insoles have been designed to decrease the force applied on the medial knee compartment. The aim of this study was to assess the effects of laterally wedged insoles regarding to the placement of the wedge under the sole (under the heel or under the forefoot on the knee adduction moment and the ground reaction forces. Material & Methods: In this pretest-posttest study, three-dimensional gait analysis was performed on 20 healthy men between 18-30 years old. Knee adduction moment and ground reaction forces were compared among following three types of insoles: a flat insole, a 6˚ laterally inclined heel wedged insole and a 6˚ laterally- inclined forefoot wedged insole. Results: there was no difference between three conditions (flat insole (9.72±1.501, lateral heel wedge (9.866±2.141 and lateral forefoot wedge (9.952±1.986 in peak knee adduction moment (P>0.05. Ground reaction forces and spatiotemporal parameters of gait were not affected by any types of these insoles (P>0.05. Conclusion: Based on the current finding, placement of the lateral wedge under the sole, that is, under the heel or under the forefoot has no effect on the efficacy of these insoles on the adduction moment of the knee and ground reaction forces.

  11. Real-Time Knee Adduction Moment Feedback for Gait Retraining Through Visual and Tactile Displays

    KAUST Repository

    Wheeler, Jason W.; Shull, Pete B.; Besier, Thor F.

    2011-01-01

    The external knee adduction moment (KAM) measured during gait is an indicator of tibiofemoral joint osteoarthritis progression and various strategies have been proposed to lower it. Gait retraining has been shown to be an effective, noninvasive approach for lowering the KAM. We present a new gait retraining approach in which the KAM is fed back to subjects in real-time during ambulation. A study was conducted in which 16 healthy subjects learned to alter gait patterns to lower the KAM through visual or tactile (vibration) feedback. Participants converged on a comfortable gait in just a few minutes by using the feedback to iterate on various kinematic modifications. All subjects adopted altered gait patterns with lower KAM compared with normal ambulation (average reduction of 20.7%). Tactile and visual feedbacks were equally effective for real-time training, although subjects using tactile feedback took longer to converge on an acceptable gait. This study shows that real-time feedback of the KAM can greatly increase the effectiveness and efficiency of subject-specific gait retraining compared with conventional methods. © 2011 American Society of Mechanical Engineers.

  12. Altered control strategy between leading and trailing leg increases knee adduction moment in the elderly while descending stairs.

    Science.gov (United States)

    Karamanidis, Kiros; Arampatzis, Adamantios

    2011-02-24

    The aim of the study was to examine the external knee adduction moments in a group of older and younger adults while descending stairs and thus the possibility of an increased risk of knee osteoarthritis due to altered knee joint loading in the elderly. Twenty-seven older and 16 younger adults descended a purpose-built staircase. A motion capture system and a force plate were used to determine the subjects' 3D kinematics and ground reaction forces (GRF) during locomotion. Calculation of the leg kinematics and kinetics was done by means of a rigid, three-segment, 3D leg model. In the initial portion of the support phase, older adults showed a more medio-posterior GRF vector relative to the ankle joint, leading to lower ankle joint moments (Pstairs by using the trailing leg before the initiation of the double support phase more compared to the younger ones. The consequence of this altered control strategy while stepping down is a more medially directed GRF vector increasing the magnitude of external knee adduction moment in the elderly. The observed changes between leading and trailing leg in the elderly may cause a redistribution of the mechanical load at the tibiofemoral joint, affecting the initiation and progression of knee osteoarthritis in the elderly. Copyright © 2010 Elsevier Ltd. All rights reserved.

  13. Combined effects of knee brace, laterally wedged insoles and toe-in gait on knee adduction moment and balance in moderate medial knee osteoarthritis patients.

    Science.gov (United States)

    Khan, Saad Jawaid; Khan, Soobia Saad; Usman, Juliana; Mokhtar, Abdul Halim; Abu Osman, Noor Azuan

    2018-03-01

    To test the hypothesis that toe-in gait (TI) will further reduce first peak (Knee Adduction Moment) KAM and decrease balance when combined with a knee brace (KB) and laterally wedged insoles (LWI) in medial knee osteoarthritis (kOA) patients. Twenty patients with bilateral symptomatic medial kOA. 4-point leverage-based KB, full-length LWI with 5° inclination and toe-in gait (TI). First and second peak knee adduction moment (fKAM and sKAM respectively), balance and pain. The fKAM and sKAM were determined from 3-dimensional gait analysis with six randomized conditions: (1) N (without any intervention), (2) KB, (3) KB + TI, (4) LWI, (5) LWI + TI, (6) KB + LWI + TI. Balance was assessed by Biodex Balance System using three stability settings, (i) Static (ii) Moderate dynamic setting for fall risk (FR12) and (iii) High dynamic setting for fall risk (FR8). The reduction in fKAM and sKAM was greatest (19.75% and 12%) when TI was combined with KB and LWI respectively. No change in balance was observed when TI combined with KB, and LWI and when used concurrently with both the orthosis at static and FR12 conditions. Significant balance reduction was found at FR8 for KB + TI (22.22%), and KB + LWI + TI (35.71%). Pain increased significantly for KB (258%), KB + TI (305%), LWI + TI (210%) and KB + LWI + TI (316%). LWI showed no effect on pain. There is a synergistic effect of TI when combined with KB and LWI concurrently in sKAM reduction. However, the concurrent use of TI, KB and LWI decreases balance and pain as assessed on a highly dynamic platform. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Immediate effect of Masai Barefoot Technology shoes on knee joint moments in women with knee osteoarthritis.

    Science.gov (United States)

    Tateuchi, Hiroshige; Taniguchi, Masashi; Takagi, Yui; Goto, Yusuke; Otsuka, Naoki; Koyama, Yumiko; Kobayashi, Masashi; Ichihashi, Noriaki

    2014-01-01

    Footwear modification can beneficially alter knee loading in patients with knee osteoarthritis. This study evaluated the effect of Masai Barefoot Technology shoes on reductions in external knee moments in patients with knee osteoarthritis. Three-dimensional motion analysis was used to examine the effect of Masai Barefoot Technology versus control shoes on the knee adduction and flexion moments in 17 women (mean age, 63.6 years) with radiographically confirmed knee osteoarthritis. The lateral and anterior trunk lean values, knee flexion and adduction angles, and ground reaction force were also evaluated. The influence of the original walking pattern on the changes in knee moments with Masai Barefoot Technology shoes was evaluated. The knee flexion moment in early stance was significantly reduced while walking with the Masai Barefoot Technology shoes (0.25±0.14Nm/kgm) as compared with walking with control shoes (0.30±0.19 Nm/kgm); whereas the knee adduction moment showed no changes. Masai Barefoot Technology shoes did not increase compensatory lateral and anterior trunk lean. The degree of knee flexion moment in the original walking pattern with control shoes was correlated directly with its reduction when wearing Masai Barefoot Technology shoes by multiple linear regression analysis (adjusted R2=0.44, Pknee flexion moment during walking without increasing the compensatory trunk lean and may therefore reduce external knee loading in women with knee osteoarthritis. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Combining valgus knee brace and lateral foot wedges reduces external forces and moments in osteoarthritis patients

    NARCIS (Netherlands)

    Jafarnezhadgero, Amir Ali; Oliveira, Anderson S.; Mousavi, Seyed Hamed; Madadi-Shad, Morteza

    Osteoarthritis progression can be related to the external knee adduction and flexion moments during walking. Lateral foot wedges and knee braces have been used as treatment for osteoarthritis, but little is known about their influence on knee joint moments generated in the sagittal and frontal

  16. Knee joint moments during high flexion movements: Timing of peak moments and the effect of safety footwear.

    Science.gov (United States)

    Chong, Helen C; Tennant, Liana M; Kingston, David C; Acker, Stacey M

    2017-03-01

    (1) Characterize knee joint moments and peak knee flexion moment timing during kneeling transitions, with the intent of identifying high-risk postures. (2) Determine whether safety footwear worn by kneeling workers (construction workers, tile setters, masons, roofers) alters high flexion kneeling mechanics. Fifteen males performed high flexion kneeling transitions. Kinetics and kinematics were analyzed for differences in ascent and descent in the lead and trail legs. Mean±standard deviation peak external knee adduction and flexion moments during transitions ranged from 1.01±0.31 to 2.04±0.66% body weight times height (BW∗Ht) and from 3.33 to 12.6% BW∗Ht respectively. The lead leg experienced significantly higher adduction moments compared to the trail leg during descent, when work boots were worn (interaction, p=0.005). There was a main effect of leg (higher lead vs. trail) on the internal rotation moment in both descent (p=0.0119) and ascent (p=0.0129) phases. Peak external knee adduction moments during transitions did not exceed those exhibited during level walking, thus increased knee adduction moment magnitude is likely not a main factor in the development of knee OA in occupational kneelers. Additionally, work boots only significantly increased the adduction moment in the lead leg during descent. In cases where one knee is painful, diseased, or injured, the unaffected knee should be used as the lead leg during asymmetric bilateral kneeling. Peak flexion moments occurred at flexion angles above the maximum flexion angle exhibited during walking (approximately 60°), supporting the theory that the loading of atypical surfaces may aid disease development or progression. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. The role of knee joint moments and knee impairments on self-reported knee pain during gait in patients with knee osteoarthritis.

    Science.gov (United States)

    O'Connell, Megan; Farrokhi, Shawn; Fitzgerald, G Kelley

    2016-01-01

    The association between high mechanical knee joint loading during gait with onset and progression of knee osteoarthritis has been extensively studied. However, less attention has been given to risk factors related to increased pain during gait. The purpose of this study was to evaluate knee joint moments and clinical characteristics that may be associated with gait-related knee pain in patients with knee osteoarthritis. Sixty-seven participants with knee osteoarthritis were stratified into three groups of no pain (n=18), mild pain (n=27), or moderate/severe pain (n=22) based on their self-reported symptoms during gait. All participants underwent three-dimensional gait analysis. Quadriceps strength, knee extension range of motion, radiographic knee alignment and self-reported measures of global pain and function were also quantified. The moderate/severe pain group demonstrated worse global pain (Pknee flexion moments during the midstance phase of gait compared to the no pain group (P=0.02). Additionally, the moderate/severe pain group demonstrated greater varus knee malalignment (P=0.009), which was associated with higher weight acceptance peak knee adduction moments (P=0.003) and worse global pain (P=0.003) and physical function scores (P=0.006). Greater knee flexion moment is present during the midstance phase of gait in patients with knee osteoarthritis and moderate/severe pain during gait. Additionally, greater varus malalignment may be a sign of increased global knee joint dysfunction that can influence many activities of daily living beyond gait. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Wide step width reduces knee abduction moment of obese adults during stair negotiation.

    Science.gov (United States)

    Yocum, Derek; Weinhandl, Joshua T; Fairbrother, Jeffrey T; Zhang, Songning

    2018-05-15

    An increased likelihood of developing obesity-related knee osteoarthritis may be associated with increased peak internal knee abduction moments (KAbM). Increases in step width (SW) may act to reduce this moment. The purpose of this study was to determine the effects of increased SW on knee biomechanics during stair negotiation of healthy-weight and obese participants. Participants (24: 10 obese and 14 healthy-weight) used stairs and walked over level ground while walking at their preferred speed in two different SW conditions - preferred and wide (200% preferred). A 2 × 2 (group × condition) mixed model analysis of variance was performed to analyze differences between groups and conditions (p < 0.05). Increased SW increased the loading-response peak knee extension moment during descent and level gait, decreased loading-response KAbMs, knee extension and abduction range of motion (ROM) during ascent, and knee adduction ROM during descent. Increased SW increased loading-response peak mediolateral ground reaction force (GRF), increased peak knee abduction angle during ascent, and decreased peak knee adduction angle during descent and level gait. Obese participants experienced disproportionate changes in loading-response mediolateral GRF, KAbM and peak adduction angle during level walking, and peak knee abduction angle and ROM during ascent. Increased SW successfully decreased loading-response peak KAbM. Implications of this finding are that increased SW may decrease medial compartment knee joint loading, decreasing pain and reducing joint deterioration. Increased SW influenced obese and healthy-weight participants differently and should be investigated further. Copyright © 2018. Published by Elsevier Ltd.

  19. Effect of foot orthoses on magnitude and timing of rearfoot and tibial motions, ground reaction force and knee moment during running.

    Science.gov (United States)

    Eslami, Mansour; Begon, Mickaël; Hinse, Sébastien; Sadeghi, Heydar; Popov, Peter; Allard, Paul

    2009-11-01

    Changes in magnitude and timing of rearfoot eversion and tibial internal rotation by foot orthoses and their contributions to vertical ground reaction force and knee joint moments are not well understood. The objectives of this study were to test if orthoses modify the magnitude and time to peak rearfoot eversion, tibial internal rotation, active ground reaction force and knee adduction moment and determine if rearfoot eversion, tibial internal rotation magnitudes are correlated to peak active ground reaction force and knee adduction moment during the first 60% stance phase of running. Eleven healthy men ran at 170 steps per minute in shod and with foot orthoses conditions. Video and force-plate data were collected simultaneously to calculate foot joint angular displacement, ground reaction forces and knee adduction moments. Results showed that wearing semi-rigid foot orthoses significantly reduced rearfoot eversion 40% (4.1 degrees ; p=0.001) and peak active ground reaction force 6% (0.96N/kg; p=0.008). No significant time differences occurred among the peak rearfoot eversion, tibial internal rotation and peak active ground reaction force in both conditions. A positive and significant correlation was observed between peak knee adduction moment and the magnitude of rearfoot eversion during shod (r=0.59; p=0.04) and shod/orthoses running (r=0.65; p=0.02). In conclusion, foot orthoses could reduce rearfoot eversion so that this can be associated with a reduction of knee adduction moment during the first 60% stance phase of running. Finding implies that modifying rearfoot and tibial motions during running could not be related to a reduction of the ground reaction force.

  20. Knee joint kinetics in response to multiple three-dimensional printed, customised foot orthoses for the treatment of medial compartment knee osteoarthritis.

    Science.gov (United States)

    Allan, Richard; Woodburn, James; Telfer, Scott; Abbott, Mandy; Steultjens, Martijn Pm

    2017-06-01

    The knee adduction moment is consistently used as a surrogate measure of medial compartment loading. Foot orthoses are designed to reduce knee adduction moment via lateral wedging. The 'dose' of wedging required to optimally unload the affected compartment is unknown and variable between individuals. This study explores a personalised approach via three-dimensional printed foot orthotics to assess the biomechanical response when two design variables are altered: orthotic length and lateral wedging. Foot orthoses were created for 10 individuals with symptomatic medial knee osteoarthritis and 10 controls. Computer-aided design software was used to design four full and four three-quarter-length foot orthoses per participant each with lateral posting of 0° 'neutral', 5° rearfoot, 10° rearfoot and 5° forefoot/10° rearfoot. Three-dimensional printers were used to manufacture all foot orthoses. Three-dimensional gait analyses were performed and selected knee kinetics were analysed: first peak knee adduction moment, second peak knee adduction moment, first knee flexion moment and knee adduction moment impulse. Full-length foot orthoses provided greater reductions in first peak knee adduction moment (p = 0.038), second peak knee adduction moment (p = 0.018) and knee adduction moment impulse (p = 0.022) compared to three-quarter-length foot orthoses. Dose effect of lateral wedging was found for first peak knee adduction moment (p knee adduction moment (p knee adduction moment impulse (p knee adduction moment (p = 0.028) and knee adduction moment impulse (p = 0.036). Significant interaction effects were found between orthotic length and wedging condition for second peak knee adduction moment (p = 0.002). No significant changes in first knee flexion moment were found. Individual heterogeneous responses to foot orthosis conditions were observed for first peak knee adduction moment, second peak knee adduction moment and knee adduction moment impulse. Biomechanical response

  1. Predicting the Functional Roles of Knee Joint Muscles from Internal Joint Moments

    DEFF Research Database (Denmark)

    Flaxman, Teresa E; Alkjær, Tine; Simonsen, Erik B

    2017-01-01

    INTRODUCTION: Knee muscles are commonly labeled as flexors or extensors and aptly stabilize the knee against sagittal plane loads. However, how these muscles stabilize the knee against adduction-abduction and rotational loads remains unclear. Our study sought 1) to classify muscle roles as they r...... on its role in maintaining knee joint stability in the frontal and transverse loading planes. This is useful for delineating the roles of biarticular knee joint muscles and could have implications in robotics, musculoskeletal modeling, sports sciences, and rehabilitation....

  2. Sagittal-Plane Knee Moment During Gait and Knee Cartilage Thickness.

    Science.gov (United States)

    Schmitz, Randy J; Harrison, David; Wang, Hsin-Min; Shultz, Sandra J

    2017-06-02

      Understanding the factors associated with thicker cartilage in a healthy population is important when developing strategies aimed at minimizing the cartilage thinning associated with knee osteoarthritis progression. Thicker articular cartilage is commonly thought to be healthier cartilage, but whether the sagittal-plane biomechanics important to gait are related to cartilage thickness is unknown.   To determine the relationship of a weight-bearing region of the medial femoral condyle's cartilage thickness to sagittal gait biomechanics in healthy individuals.   Descriptive laboratory study.   Laboratory.   Twenty-eight healthy participants (15 women: age = 21.1 ± 2.1 years, height = 1.63 ± 0.07 m, weight = 64.6 ± 9.9 kg; 13 men: age = 22.1 ± 2.9 years, height = 1.79 ± 0.05 m, weight = 75.2 ± 9.6 kg).   Tibiofemoral angle (°) was obtained via goniometric assessment, thickness of the medial femoral condyle cartilage (mm) was obtained via ultrasound imaging, and peak internal knee-extensor moment (% body weight · height) was measured during 10 trials of over-ground walking at a self-selected pace. We used linear regression to examine the extent to which peak internal knee-extensor moment predicted cartilage thickness after accounting for tibiofemoral angle and sex.   Sex and tibiofemoral angle (12.3° ± 3.2°) were entered in the initial step as control factors (R 2 = 0.01, P = .872). In the final step, internal knee-extensor moment (1.5% ± 1.3% body weight · height) was entered, which resulted in greater knee-extensor moment being related to greater cartilage thickness (2.0 ± 0.3 mm; R 2 Δ = 0.31, PΔ = .003).   Individuals who walked with a greater peak internal knee-extensor moment during gait had a cartilage structure that is generally considered beneficial in a healthy population. Our study offers promising findings that a potentially modifiable biomechanical factor is associated with cartilage status in a healthy population

  3. Abdominal Hollowing Reduces Lateral Trunk Displacement During Single-Leg Squats in Healthy Females But Does Not Affect Peak Hip Abduction Angle or Knee Abductio Angle/Moment.

    Science.gov (United States)

    Linde, Lukas D; Archibald, Jessica; Lampert, Eve C; Srbely, John Z

    2017-07-17

    Females suffer 4-6 times more non-contact anterior cruciate ligament (ACL) injuries than males due to neuromuscular control deficits of the hip musculature leading to increases in hip adduction angle, knee abduction angle, and knee abduction moment during dynamic tasks such as single-leg squats. Lateral trunk displacement has been further related to ACL injury risk in females, leading to the incorporation of core strength/stability exercises in ACL preventative training programs. However, the direct mechanism relating lateral trunk displacement and lower limb ACL risk factors is not well established. To assess the relationship between lateral trunk displacement and lower limb measures of ACL injury risk by altering trunk control through abdominal activation techniques during single-leg squats in healthy females. Interventional Study Setting: Movement and Posture Laboratory Participants: 13 healthy females (21.3±0.88y, 1.68±0.07m, 58.27±5.46kg) Intervention: Trunk position and lower limb kinematics were recorded using an optoelectric motion capture system during single-leg squats under differing conditions of abdominal muscle activation (abdominal hollowing, abdominal bracing, control), confirmed via surface electromyography. Lateral trunk displacement, peak hip adduction angle, peak knee abduction angle/moment, and average muscle activity from bilateral internal oblique, external oblique, and erector spinae muscles. No differences were observed for peak lateral trunk displacement, peak hip adduction angle or peak knee abduction angle/moment. Abdominal hollowing and bracing elicited greater muscle activation than the control condition, and bracing was greater than hollowing in four of six muscles recorded. The lack of reduction in trunk, hip, and knee measures of ACL injury risk during abdominal hollowing and bracing suggests that these techniques alone may provide minimal benefit in ACL injury prevention training.

  4. Real-time feedback on knee abduction moment does not improve frontal-plane knee mechanics during jump landings.

    Science.gov (United States)

    Beaulieu, M L; Palmieri-Smith, R M

    2014-08-01

    Excessive knee abduction loading is a contributing factor to anterior cruciate ligament (ACL) injury risk. The purpose of this study was to determine whether a double-leg landing training program with real-time visual feedback improves frontal-plane mechanics during double- and single-leg landings. Knee abduction angles and moments and vertical ground reaction forces (GRF) of 21 recreationally active women were quantified for double- and single-leg landings before and after the training program. This program consisted of two sessions of double-leg jump landings with real-time visual feedback on knee abduction moments for the experimental group and without real-time feedback for the control group. No significant differences were found between training groups. In comparison with pre-training data, peak knee abduction moments decreased 12% post-training for both double- and single-leg landings; whereas peak vertical GRF decreased 8% post-training for double-leg landings only, irrespective of training group. Real-time feedback on knee abduction moments, therefore, did not significantly improve frontal-plane knee mechanics during landings. The effect of the training program on knee abduction moments, however, transferred from the double-leg landings (simple task) to single-leg landings (more complex task). Consequently, ACL injury prevention efforts may not need to focus on complex tasks during which injury occurs. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Differences in Knee and Hip Adduction and Hip Muscle Activation in Runners With and Without Iliotibial Band Syndrome.

    Science.gov (United States)

    Baker, Robert L; Souza, Richard B; Rauh, Mitchell J; Fredericson, Michael; Rosenthal, Michael D

    2018-04-26

    Iliotibial band syndrome has been associated with altered hip and knee kinematics in runners. Previous studies have recommended further research on neuromuscular factors at the hip. The frontal plane hip muscles have been a strong focus in strength comparison but not for electromyography investigation. To compare hip surface electromyography, and frontal plane hip and knee kinematics, in runners with and without iliotibial band syndrome. Observational cross-sectional study. Thirty participants were tested for motion capture at the hip and knee and muscle activation in the lateral and posterior hip. Biomechanics research laboratory within a university. Thirty subjects were recruited consisting of 15 injured runners with iliotibial band syndrome and 15 gender-, age-, and body mass index-matched controls. In each group, 8 were male runners and 7 were female runners. Inclusion criteria for the injured group were pain within 2 months related to iliotibial band syndrome and a positive Noble compression test. Participants were excluded if they reported other lower extremity diagnoses within the last year or active lower extremity or low back pain not related to iliotibial band syndrome. Controls were excluded if they reported a history of iliotibial band syndrome. Convenience sampling was used based on referrals from local running clinics and orthopedic clinics. Three-dimensional motion capture was performed with 10 high-speed cameras synchronized with wireless surface electromyography during a 30-minute run. The first data point was at 3 minutes, using a constant speed of 2.74 meters per second. A second data point was at 30 minutes, using a self-selected pace by the participant to allow for a challenging run until completion at 30 minutes. Motion capture was reported as peak kinematic values from heel strike to peak knee flexion for hip adduction and knee adduction. Surface electromyography was reported as a percentage of maximal voluntary contraction for the gluteus

  6. Composition of The Knee Index, a novel three-dimensional biomechanical index for knee joint load, in subjects with mild to moderate knee osteoarthritis

    DEFF Research Database (Denmark)

    Clausen, Brian; Andriacchi, Tom; Nielsen, Dennis Brandborg

    Background Knee joint load is an important factor associated with progression of knee osteoarthritis. To provide an overall understanding of knee joint loading, the Knee Index (KI) has been developed to include moments from all three planes (frontal, sagittal and transversal). However, before KI...... index of joint load for the knee, in patients with mild to moderate knee osteoarthritis. Methods The contribution of frontal, sagittal and transversal plane knee moments to KI was investigated in 24 subjects (13 women, age: 58 ± 7.6 years, BMI: 27.1 ± 3.0) with clinically diagnosed mild to moderate knee...... kinematics (i.e. the knee adduction moment), and secondarily the sagittal plane kinematics (i.e. the knee flexion moment). This holds promise for using KI in clinical trials since both frontal and sagittal knee joint moments have been suggested to be associated with the knee osteoarthritis disease...

  7. Knee joint passive stiffness and moment in sagittal and frontal planes markedly increase with compression.

    Science.gov (United States)

    Marouane, H; Shirazi-Adl, A; Adouni, M

    2015-01-01

    Knee joints are subject to large compression forces in daily activities. Due to artefact moments and instability under large compression loads, biomechanical studies impose additional constraints to circumvent the compression position-dependency in response. To quantify the effect of compression on passive knee moment resistance and stiffness, two validated finite element models of the tibiofemoral (TF) joint, one refined with depth-dependent fibril-reinforced cartilage and the other less refined with homogeneous isotropic cartilage, are used. The unconstrained TF joint response in sagittal and frontal planes is investigated at different flexion angles (0°, 15°, 30° and 45°) up to 1800 N compression preloads. The compression is applied at a novel joint mechanical balance point (MBP) identified as a point at which the compression does not cause any coupled rotations in sagittal and frontal planes. The MBP of the unconstrained joint is located at the lateral plateau in small compressions and shifts medially towards the inter-compartmental area at larger compression forces. The compression force substantially increases the joint moment-bearing capacities and instantaneous angular rigidities in both frontal and sagittal planes. The varus-valgus laxities diminish with compression preloads despite concomitant substantial reductions in collateral ligament forces. While the angular rigidity would enhance the joint stability, the augmented passive moment resistance under compression preloads plays a role in supporting external moments and should as such be considered in the knee joint musculoskeletal models.

  8. Effect of an ankle-foot orthosis on knee joint mechanics: a novel conservative treatment for knee osteoarthritis.

    Science.gov (United States)

    Fantini Pagani, Cynthia H; Willwacher, Steffen; Benker, Rita; Brüggemann, Gert-Peter

    2014-12-01

    Several conservative treatments for medial knee osteoarthritis such as knee orthosis and laterally wedged insoles have been shown to reduce the load in the medial knee compartment. However, those treatments also present limitations such as patient compliance and inconsistent results regarding the treatment success. To analyze the effect of an ankle-foot orthosis on the knee adduction moment and knee joint alignment in the frontal plane in subjects with knee varus alignment. Controlled laboratory study, repeated measurements. In total, 14 healthy subjects with knee varus alignment were analyzed in five different conditions: without orthotic, with laterally wedged insoles, and with an ankle-foot orthosis in three different adjustments. Three-dimensional kinetic and kinematic data were collected during gait analysis. Significant decreases in knee adduction moment, knee lever arm, and joint alignment in the frontal plane were observed with the ankle-foot orthosis in all three different adjustments. No significant differences could be found in any parameter while using the laterally wedged insoles. The ankle-foot orthosis was effective in reducing the knee adduction moment. The decreases in this parameter seem to be achieved by changing the knee joint alignment and thereby reducing the knee lever arm in the frontal plane. This study presents a novel approach for reducing the load in the medial knee compartment, which could be developed as a new treatment option for patients with medial knee osteoarthritis. © The International Society for Prosthetics and Orthotics 2013.

  9. Lateral trunk lean and medializing the knee as gait strategies for knee osteoarthritis

    NARCIS (Netherlands)

    Gerbrands, T. A.; Pisters, M. F.; Theeven, P. J R; Verschueren, S.; Vanwanseele, B.

    2017-01-01

    Objective To determine (1) if Medial Thrust or Trunk Lean reduces the knee adduction moment (EKAM) the most during gait in patients with medial knee osteoarthritis, (2) if the best overall strategy is the most effective for each patient and (3) if these strategies affect ankle and hip kinetics.

  10. Patterns in the knee flexion-extension moment profile during stair ascent and descent in patients with total knee arthroplasty.

    Science.gov (United States)

    McClelland, Jodie A; Feller, Julian A; Menz, Hylton B; Webster, Kate E

    2014-06-03

    The aim of this study was to investigate the prevalence of abnormal knee biomechanical patterns in 40 patients with a modern TKA prosthesis, compared to 40 matched control participants when ascending and descending stairs. Fewer patients were able to ascend (65%) or descend stairs (53%) unassisted than controls (83%). Of the participants who could ascend and descend, cluster analysis classified most patients (up to 77%) as demonstrating a similar knee moment pattern as all controls. A small subgroup of patients who completed the tasks did so with distinctly abnormal biomechanics compared to other patients and controls. These findings suggest that recovery of normal stair climbing is possible. However, rehabilitation might be more effective if it were tailored to account for these differences between patients. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Knee Moment-Angle Characteristics and Semitendinosus Muscle Morphology in Children with Spastic Paresis Selected for Medial Hamstring Lengthening.

    Science.gov (United States)

    Haberfehlner, Helga; Jaspers, Richard T; Rutz, Erich; Becher, Jules G; Harlaar, Jaap; van der Sluijs, Johannes A; Witbreuk, Melinda M; Romkes, Jacqueline; Freslier, Marie; Brunner, Reinald; Maas, Huub; Buizer, Annemieke I

    2016-01-01

    To increase knee range of motion and improve gait in children with spastic paresis (SP), the semitendinosus muscle (ST) amongst other hamstring muscles is frequently lengthened by surgery, but with variable success. Little is known about how the pre-surgical mechanical and morphological characteristics of ST muscle differ between children with SP and typically developing children (TD). The aims of this study were to assess (1) how knee moment-angle characteristics and ST morphology in children with SP selected for medial hamstring lengthening differ from TD children, as well as (2) how knee moment-angle characteristics and ST morphology are related. In nine SP and nine TD children, passive knee moment-angle characteristics and morphology of ST (i.e. fascicle length, muscle belly length, tendon length, physiological cross-sectional area, and volume) were assessed by hand-held dynamometry and freehand 3D ultrasound, respectively. At net knee flexion moments above 0.5 Nm, more flexed knee angles were found for SP compared to TD children. The measured knee angle range between 0 and 4 Nm was 30% smaller in children with SP. Muscle volume, physiological cross-sectional area, and fascicle length normalized to femur length were smaller in SP compared to TD children (62%, 48%, and 18%, respectively). Sixty percent of the variation in knee angles at 4 Nm net knee moment was explained by ST fascicle length. Altered knee moment-angle characteristics indicate an increased ST stiffness in SP children. Morphological observations indicate that in SP children planned for medial hamstring lengthening, the longitudinal and cross-sectional growth of ST muscle fibers is reduced. The reduced fascicle length can partly explain the increased ST stiffness and, hence, a more flexed knee joint in these SP children.

  12. Body mass index affects knee joint mechanics during gait differently with and without moderate knee osteoarthritis.

    Science.gov (United States)

    Harding, Graeme T; Hubley-Kozey, Cheryl L; Dunbar, Michael J; Stanish, William D; Astephen Wilson, Janie L

    2012-11-01

    Obesity is a highly cited risk factor for knee osteoarthritis (OA), but its role in knee OA pathogenesis and progression is not as clear. Excess weight may contribute to an increased mechanical burden and altered dynamic movement and loading patterns at the knee. The objective of this study was to examine the interacting role of moderate knee OA disease presence and obesity on knee joint mechanics during gait. Gait analysis was performed on 104 asymptomatic and 140 individuals with moderate knee OA. Each subject group was divided into three body mass categories based on body mass index (BMI): healthy weight (BMI30). Three-dimensional knee joint angles and net external knee joint moments were calculated and waveform principal component analysis (PCA) was applied to extract major patterns of variability from each. PC scores for major patterns were compared between groups using a two-factor ANOVA. Significant BMI main effects were found in the pattern of the knee adduction moment, the knee flexion moment, and the knee rotation moment during gait. Two interaction effects between moderate OA disease presence and BMI were also found that described different changes in the knee flexion moment and the knee flexion angle with increased BMI with and without knee OA. Our results suggest that increased BMI is associated with different changes in biomechanical patterns of the knee joint during gait depending on the presence of moderate knee OA. Copyright © 2012 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  13. Neuromuscular versus quadriceps strengthening exercise in patients with medial knee osteoarthritis and varus malalignment

    DEFF Research Database (Denmark)

    Bennell, Kim L; Kyriakides, Mary; Metcalf, Ben

    2014-01-01

    OBJECTIVE: To compare the effects of neuromuscular exercise (NEXA) and quadriceps strengthening (QS) on the knee adduction moment (an indicator of mediolateral distribution of knee load), pain, and physical function in patients with medial knee joint osteoarthritis (OA) and varus malalignment. ME...

  14. Comparison of the angles and corresponding moments in the knee and hip during restricted and unrestricted squats.

    Science.gov (United States)

    Lorenzetti, Silvio; Gülay, Turgut; Stoop, Mirjam; List, Renate; Gerber, Hans; Schellenberg, Florian; Stüssi, Edgar

    2012-10-01

    The aim of this study was to compare the angles and corresponding moments in the knee and hip during squats. Twenty subjects performed restricted and unrestricted squats with barbell loads that were 0, ¼, and ½ their body weight. The experimental setup consisted of a motion capture system and 2 force plates. The moments were calculated using inverse dynamics. During the unrestricted squats, the maximum moments in the knee were significantly higher, and those in the hip were significantly lower than during restricted squats. At the lowest position, the maximum knee flexion angles were approximately 86° for the restricted and approximately 106° for the unrestricted techniques, whereas the maximum hip flexion angle was between 95° and 100°. The higher moments in the hip during restricted squats suggest a higher load of the lower back. Athletes who aim to strengthen their quadriceps should consider unrestricted squats because of the larger knee load and smaller back load.

  15. The associations between quadriceps muscle strength, power, and knee joint mechanics in knee osteoarthritis: A cross-sectional study.

    Science.gov (United States)

    Murray, Amanda M; Thomas, Abbey C; Armstrong, Charles W; Pietrosimone, Brian G; Tevald, Michael A

    2015-12-01

    Abnormal knee joint mechanics have been implicated in the pathogenesis and progression of knee osteoarthritis. Deficits in muscle function (i.e., strength and power) may contribute to abnormal knee joint loading. The associations between quadriceps strength, power and knee joint mechanics remain unclear in knee osteoarthritis. Three-dimensional motion analysis was used to collect peak knee joint angles and moments during the first 50% of stance phase of gait in 33 participants with knee osteoarthritis. Quadriceps strength and power were assessed using a knee extension machine. Strength was quantified as the one repetition maximum. Power was quantified as the peak power produced at 40-90% of the one repetition maximum. Quadriceps strength accounted for 15% of the variance in peak knee flexion angle (P=0.016). Quadriceps power accounted for 20-29% of the variance in peak knee flexion angle (Pknee adduction moment (P=0.05). These data suggest that quadriceps power explains more variance in knee flexion angle and knee adduction moment during gait in knee osteoarthritis than quadriceps strength. Additionally, quadriceps power at multiple loads is associated with knee joint mechanics and therefore should be assessed at a variety of loads. Taken together, these results indicate that quadriceps power may be a potential target for interventions aimed at changing knee joint mechanics in knee osteoarthritis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. The effect on knee-joint load of instruction in analgesic use compared with neuromuscular exercise in patients with knee osteoarthritis

    DEFF Research Database (Denmark)

    Clausen, Brian; Holsgaard-Larsen, Anders; Søndergaard, Jens

    2014-01-01

    , compared with optimized analgesics and antiinflammatory drug use, on the measures of knee-joint load in people with mild to moderate medial tibiofemoral knee osteoarthritis. METHOD/DESIGN: One hundred men and women with mild to moderate medial knee osteoarthritis will be recruited from general medical...... during walking (the Knee Index, a composite score of the first external peak total reaction moment on the knee joint from all three planes based on 3D movement analysis) after 8 weeks of intervention. Secondary outcomes include changes in the external peak knee-adduction moment and impulse and functional...

  17. Longitudinal Increases in Knee Abduction Moments in Females during Adolescent Growth

    Science.gov (United States)

    HEWETT, TIMOTHY E.; MYER, GREGORY D.; KIEFER, ADAM W.; FORD, KEVIN R.

    2015-01-01

    ABSTRACT Purpose Knee abduction moment (KAM) is an injury risk factor for anterior cruciate ligament (ACL) injury that shows divergent incidence between males and females during adolescence. The objective of this study was to determine the relation between skeletal growth and increased KAM. The hypotheses tested were that females would demonstrate peak KAM during landing at peak height velocity (PHV) and that they would diverge from males at PHV. Methods The subject pool consisted of 674 females and 218 males (1387 female and 376 male assessments) who participated in a preseason testing session before their basketball or soccer seasons. They were tested longitudinally for multiple years (2 ± 1 yr) to capture maturation via estimates of percent (%) adult stature and biomechanical analysis during a drop vertical jump maneuver. Data were analyzed using three-dimensional motion analysis that used a 37 retroreflective marker body model and inverse dynamics to calculate segment joint centers and peak KAM. Results Mature females, as defined as 92% adult stature or greater, displayed increased peak KAM and knee abduction angles relative to growing (≤91% adult stature) adolescent females (P injury in females. KAM peaked in females at PHV. Tracking longitudinal increases in peak KAM may be useful for the identification of females at increased risk of ACL injury. PMID:25970663

  18. Antagonist muscle moment is increased in ACL deficient subjects during maximal dynamic knee extension

    DEFF Research Database (Denmark)

    Alkjær, Tine; Simonsen, Erik B; Magnusson, S Peter

    2012-01-01

    INTRODUCTION: Coactivation of the hamstring muscles during dynamic knee extension may compensate for increased knee joint laxity in anterior cruciate ligament (ACL) deficient subjects. This study examined if antagonist muscle coactivation during maximal dynamic knee extension was elevated...

  19. Decreased Knee Joint Loading Associated With Early Knee Osteoarthritis After Anterior Cruciate Ligament Injury.

    Science.gov (United States)

    Wellsandt, Elizabeth; Gardinier, Emily S; Manal, Kurt; Axe, Michael J; Buchanan, Thomas S; Snyder-Mackler, Lynn

    2016-01-01

    Anterior cruciate ligament (ACL) injury predisposes individuals to early-onset knee joint osteoarthritis (OA). Abnormal joint loading is apparent after ACL injury and reconstruction. The relationship between altered joint biomechanics and the development of knee OA is unknown. Altered knee joint kinetics and medial compartment contact forces initially after injury and reconstruction are associated with radiographic knee OA 5 years after reconstruction. Case-control study; Level of evidence, 3. Individuals with acute, unilateral ACL injury completed gait analysis before (baseline) and after (posttraining) preoperative rehabilitation and at 6 months, 1 year, and 2 years after reconstruction. Surface electromyographic and knee biomechanical data served as inputs to an electromyographically driven musculoskeletal model to estimate knee joint contact forces. Patients completed radiographic testing 5 years after reconstruction. Differences in knee joint kinetics and contact forces were compared between patients with and those without radiographic knee OA. Patients with OA walked with greater frontal plane interlimb differences than those without OA (nonOA) at baseline (peak knee adduction moment difference: 0.00 ± 0.08 N·m/kg·m [nonOA] vs -0.15 ± 0.09 N·m/kg·m [OA], P = .014; peak knee adduction moment impulse difference: -0.001 ± 0.032 N·m·s/kg·m [nonOA] vs -0.048 ± 0.031 N·m·s/kg·m [OA], P = .042). The involved limb knee adduction moment impulse of the group with osteoarthritis was also lower than that of the group without osteoarthritis at baseline (0.087 ± 0.023 N·m·s/kg·m [nonOA] vs 0.049 ± 0.018 N·m·s/kg·m [OA], P = .023). Significant group differences were absent at posttraining but reemerged 6 months after reconstruction (peak knee adduction moment difference: 0.02 ± 0.04 N·m/kg·m [nonOA] vs -0.06 ± 0.11 N·m/kg·m [OA], P = .043). In addition, the OA group walked with lower peak medial compartment contact forces of the involved limb

  20. 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.

  1. Effects of Knee Alignments and Toe Clip on Frontal Plane Knee Biomechanics in Cycling

    Science.gov (United States)

    Shen, Guangping; Zhang, Songning; Bennett, Hunter J.; Martin, James C.; Crouter, Scott E.; Fitzhugh, Eugene C.

    2018-01-01

    Effects of knee alignment on the internal knee abduction moment (KAM) in walking have been widely studied. The KAM is closely associated with the development of medial knee osteoarthritis. Despite the importance of knee alignment, no studies have explored its effects on knee frontal plane biomechanics during stationary cycling. The purpose of this study was to examine the effects of knee alignment and use of a toe clip on the knee frontal plane biomechanics during stationary cycling. A total of 32 participants (11 varus, 11 neutral, and 10 valgus alignment) performed five trials in each of six cycling conditions: pedaling at 80 rpm and 0.5 kg (40 Watts), 1.0 kg (78 Watts), and 1.5 kg (117 Watts) with and without a toe clip. A motion analysis system and a customized instrumented pedal were used to collect 3D kinematic and kinetic data. A 3 × 2 × 3 (group × toe clip × workload) mixed design ANOVA was used for statistical analysis (p < 0.05). There were two different knee frontal plane loading patterns, internal abduction and adduction moment, which were affected by knee alignment type. The knee adduction angle was 12.2° greater in the varus group compared to the valgus group (p = 0.001), yet no difference was found for KAM among groups. Wearing a toe clip increased the knee adduction angle by 0.95º (p = 0.005). The findings of this study indicate that stationary cycling may be a safe exercise prescription for people with knee malalignments. In addition, using a toe clip may not have any negative effects on knee joints during stationary cycling. Key points Varus or valgus alignment did not cause increased frontal-plane knee joint loading, suggesting stationary cycling is a safe exercise. This study supports that using a toe clip did not lead to abnormal frontal-plane knee loading during stationary cycling. Two different knee frontal plane loading patterns, knee abduction and adduction moment, were observed during stationary cycling, which are likely affected by

  2. Effects of Knee Alignments and Toe Clip on Frontal Plane Knee Biomechanics in Cycling.

    Science.gov (United States)

    Shen, Guangping; Zhang, Songning; Bennett, Hunter J; Martin, James C; Crouter, Scott E; Fitzhugh, Eugene C

    2018-06-01

    Effects of knee alignment on the internal knee abduction moment (KAM) in walking have been widely studied. The KAM is closely associated with the development of medial knee osteoarthritis. Despite the importance of knee alignment, no studies have explored its effects on knee frontal plane biomechanics during stationary cycling. The purpose of this study was to examine the effects of knee alignment and use of a toe clip on the knee frontal plane biomechanics during stationary cycling. A total of 32 participants (11 varus, 11 neutral, and 10 valgus alignment) performed five trials in each of six cycling conditions: pedaling at 80 rpm and 0.5 kg (40 Watts), 1.0 kg (78 Watts), and 1.5 kg (117 Watts) with and without a toe clip. A motion analysis system and a customized instrumented pedal were used to collect 3D kinematic and kinetic data. A 3 × 2 × 3 (group × toe clip × workload) mixed design ANOVA was used for statistical analysis (p < 0.05). There were two different knee frontal plane loading patterns, internal abduction and adduction moment, which were affected by knee alignment type. The knee adduction angle was 12.2° greater in the varus group compared to the valgus group (p = 0.001), yet no difference was found for KAM among groups. Wearing a toe clip increased the knee adduction angle by 0.95º (p = 0.005). The findings of this study indicate that stationary cycling may be a safe exercise prescription for people with knee malalignments. In addition, using a toe clip may not have any negative effects on knee joints during stationary cycling.

  3. Lower extremity joint moments of collegiate soccer players differ between genders during a forward jump.

    Science.gov (United States)

    Hart, Joseph M; Garrison, J Craig; Palmieri-Smith, Riann; Kerrigan, D Casey; Ingersoll, Christopher D

    2008-05-01

    Lower extremity kinetics while performing a single-leg forward jump landing may help explain gender biased risk for noncontact anterior cruciate ligament injury. Gender comparison of lower extremity joint angles and moments. Static groups comparison. Motion analysis laboratory. 8 male and 8 female varsity, collegiate soccer athletes. 5 single-leg landings from a 100cm forward jump. Peak and initial contact external joint moments and joint angles of the ankle, knee, and hip. At initial heel contact, males exhibited a adduction moment whereas females exhibited a abduction moment at the hip. Females also had significantly less peak hip extension moment and significantly less peak hip internal rotation moment than males had. Females exhibited greater knee adduction and hip internal rotation angles than men did. When decelerating from a forward jump, gender differences exist in forces acting at the hip.

  4. Does shoe heel design influence ground reaction forces and knee moments during maximum lunges in elite and intermediate badminton players?

    Directory of Open Access Journals (Sweden)

    Wing-Kai Lam

    Full Text Available Lunge is one frequently executed movement in badminton and involves a unique sagittal footstrike angle of more than 40 degrees at initial ground contact compared with other manoeuvres. This study examined if the shoe heel curvature design of a badminton shoe would influence shoe-ground kinematics, ground reaction forces, and knee moments during lunge.Eleven elite and fifteen intermediate players performed five left-forward maximum lunge trials with Rounded Heel Shoe (RHS, Flattened Heel Shoe (FHS, and Standard Heel Shoes (SHS. Shoe-ground kinematics, ground reaction forces, and knee moments were measured by using synchronized force platform and motion analysis system. A 2 (Group x 3 (Shoe ANOVA with repeated measures was performed to determine the effects of different shoes and different playing levels, as well as the interaction of two factors on all variables.Shoe effect indicated that players demonstrated lower maximum vertical loading rate in RHS than the other two shoes (P < 0.05. Group effect revealed that elite players exhibited larger footstrike angle, faster approaching speed, lower peak horizontal force and horizontal loading rates but higher vertical loading rates and larger peak knee flexion and extension moments (P < 0.05. Analysis of Interactions of Group x Shoe for maximum and mean vertical loading rates (P < 0.05 indicated that elite players exhibited lower left maximum and mean vertical loading rates in RHS compared to FHS (P < 0.01, while the intermediate group did not show any Shoe effect on vertical loading rates.These findings indicate that shoe heel curvature would play some role in altering ground reaction force impact during badminton lunge. The differences in impact loads and knee moments between elite and intermediate players may be useful in optimizing footwear design and training strategy to minimize the potential risks for impact related injuries in badminton.

  5. Does shoe heel design influence ground reaction forces and knee moments during maximum lunges in elite and intermediate badminton players?

    Science.gov (United States)

    Lam, Wing-Kai; Ryue, Jaejin; Lee, Ki-Kwang; Park, Sang-Kyoon; Cheung, Jason Tak-Man; Ryu, Jiseon

    2017-01-01

    Lunge is one frequently executed movement in badminton and involves a unique sagittal footstrike angle of more than 40 degrees at initial ground contact compared with other manoeuvres. This study examined if the shoe heel curvature design of a badminton shoe would influence shoe-ground kinematics, ground reaction forces, and knee moments during lunge. Eleven elite and fifteen intermediate players performed five left-forward maximum lunge trials with Rounded Heel Shoe (RHS), Flattened Heel Shoe (FHS), and Standard Heel Shoes (SHS). Shoe-ground kinematics, ground reaction forces, and knee moments were measured by using synchronized force platform and motion analysis system. A 2 (Group) x 3 (Shoe) ANOVA with repeated measures was performed to determine the effects of different shoes and different playing levels, as well as the interaction of two factors on all variables. Shoe effect indicated that players demonstrated lower maximum vertical loading rate in RHS than the other two shoes (P badminton lunge. The differences in impact loads and knee moments between elite and intermediate players may be useful in optimizing footwear design and training strategy to minimize the potential risks for impact related injuries in badminton.

  6. The effect of shoe design and lateral wedges on knee load and neuromuscular control in healthy subjects during walking

    DEFF Research Database (Denmark)

    Mølgaard, Carsten Møller; Kersting, Uwe G.

    2013-01-01

    and second peak knee adduction moments. However, the variability of this moment between shoe designs was of similar magnitude as the effect of laterally wedged insoles. Only marginal changes in muscle activity for gastrocnemius when walking with the wedged Oxford shoe were revealed. Conclusion: Lateral...

  7. Effects of toe-in and toe-in with wider step width on level walking knee biomechanics in varus, valgus, and neutral knee alignments.

    Science.gov (United States)

    Bennett, Hunter J; Shen, Guangping; Cates, Harold E; Zhang, Songning

    2017-12-01

    Increased peak external knee adduction moments exist for individuals with knee osteoarthritis and varus knee alignments, compared to healthy and neutrally aligned counterparts. Walking with increased toe-in or increased step width have been individually utilized to successfully reduce 1st and 2nd peak knee adduction moments, respectfully, but have not previously been combined or tested among all alignment groups. The purpose of this study was to compare toe-in only and toe-in with wider step width gait modifications in individuals with neutral, valgus, and varus alignments. Thirty-eight healthy participants with confirmed varus, neutral, or valgus frontal-plane knee alignment through anteroposterior radiographs, performed level walking in normal, toe-in, and toe-in with wider step width gaits. A 3×3 (group×intervention) mixed model repeated measures ANOVA compared alignment groups and gait interventions (pstep width compared to normal gait. The 2nd peak adduction moment was increased in toe-in compared to normal and toe-in with wider step width. The adduction impulse was also reduced in toe-in and toe-in with wider step width compared to normal gait. Peak knee flexion and external rotation moments were increased in toe-in and toe-in with wider step width compared to normal gait. Although the toe-in with wider step width gait seems to be a viable option to reduce peak adduction moments for varus alignments, sagittal, and transverse knee loadings should be monitored when implementing this gait modification strategy. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. The Immediate Effects of Conventional Physical Therapy on the Knee Joint Load in Subjects with Moderate Knee Osteoarthritis; A Preliminary Single Blinded Randomized Control Trial

    Directory of Open Access Journals (Sweden)

    Leila Fattahi

    2015-12-01

    Full Text Available Background: Subjects with knee osteoarthritis typically have higher knee adduction moment. Current research efforts are mainly focused on therapeutic procedures that potentially may modify disease progression. This preliminary study was designed as a single blind (examiner randomized control trial to investigate the impact of conventional physical therapy on pain, and knee joint load in subjects with moderate knee osteoarthritis. Methods: Twelve participants diagnosed with moderate knee OA were randomly assigned into control and intervention groups. Three-dimensional knee kinematic and kinetic data were recorded during the gait before and after 10 sessions of conventional physical therapy. In addition, pain intensity was evaluated by visual analog scale and pain subscale of KOOS questionnaire. The control group did not receive any intervention during the same period. Gait parameters were analyzed within and between groups using nonparametric tests. Results: There was a significant difference between groups in baseline KOOS-pain Score and ML knee force (P=0.048 and P=0.01. Immediately after ten sessions of physical therapy the initial (first peak of knee adduction moment was significantly (P=0.03 lower than that of the control group while the first and second peak of knee AP velocity were significantly (P=0.02, P=0.01 respectively higher. In the intervention group, the second peaks of vertical and anteroposterior (AP knee forces were strongly correlated with the pretest KOOS-pain Score (r=0.99 and r=0.98, P<0.001. Therefore a multivariate general linear model was adopted with adjustment to baseline KOOS-pain. By this adjustment, 51% alleviation of VAS pain score and 81% decrement of first peak of knee adduction moment in comparison to control group was statistically significant (P=0.02, P=0.03 respectively. Conclusion: It seems that ten sessions of conventional physical therapy may modify knee joint load in subjects with moderate knee

  9. The association between knee joint biomechanics and neuromuscular control and moderate knee osteoarthritis radiographic and pain severity.

    Science.gov (United States)

    Astephen Wilson, J L; Deluzio, K J; Dunbar, M J; Caldwell, G E; Hubley-Kozey, C L

    2011-02-01

    The objective of this study was to determine the association between biomechanical and neuromuscular factors of clinically diagnosed mild to moderate knee osteoarthritis (OA) with radiographic severity and pain severity separately. Three-dimensional gait analysis and electromyography were performed on a group of 40 participants with clinically diagnosed mild to moderate medial knee OA. Associations between radiographic severity, defined using a visual analog radiographic score, and pain severity, defined with the pain subscale of the WOMAC osteoarthritis index, with knee joint kinematics and kinetics, electromyography patterns of periarticular knee muscles, BMI and gait speed were determined with correlation analyses. Multiple linear regression analyses of radiographic and pain severity were also explored. Statistically significant correlations between radiographic severity and the overall magnitude of the knee adduction moment during stance (r²=21.4%, P=0.003) and the magnitude of the knee flexion angle during the gait cycle (r²=11.4%, P=0.03) were found. Significant correlations between pain and gait speed (r²=28.2%, Pjoint biomechanical variables are associated with structural knee OA severity measured from radiographs in clinically diagnosed mild to moderate levels of disease, but that pain severity is only reflected in gait speed and neuromuscular activation patterns. A combination of the knee adduction moment and BMI better explained structural knee OA severity than any individual factor alone. Copyright © 2010 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  10. Mechanical factors relate to pain in knee osteoarthritis.

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    Maly, Monica R; Costigan, Patrick A; Olney, Sandra J

    2008-07-01

    Pain experienced by people with knee osteoarthritis is related to psychosocial factors and damage to articular tissues and/or the pain pathway itself. Mechanical factors have been speculated to trigger this pain experience; yet mechanics have not been identified as a source of pain in this population. The purpose of this study was to identify whether mechanics could explain variance in pain intensity in people with knee osteoarthritis. Data from 53 participants with physician-diagnosed knee osteoarthritis (mean age=68.5 years; standard deviation=8.6 years) were analyzed. Pain intensity was reported on the Western Ontario and McMaster Universities Osteoarthritis Index. Mechanical measures included weight-bearing varus-valgus alignment, body mass index and isokinetic quadriceps torque. Gait analysis captured the range of adduction-abduction angle, range of flexion-extension angle and external knee adduction moment during level walking. Pain intensity was significantly related to the dynamic range of flexion-extension during gait and body mass index. A total of 29% of the variance in pain intensity was explained by mechanical variables. The range of flexion-extension explained 18% of variance in pain intensity. Body mass index added 11% to the model. The knee adduction moment was unrelated to pain intensity. The findings support that mechanical factors are related to knee osteoarthritis pain. Because limitations in flexion-extension range of motion and body size are modifiable factors, future research could examine whether interventions targeting these mechanics would facilitate pain management.

  11. Increased knee valgus alignment and moment during single-leg landing after overhead stroke as a potential risk factor of anterior cruciate ligament injury in badminton.

    Science.gov (United States)

    Kimura, Yuka; Ishibashi, Yasuyuki; Tsuda, Eiichi; Yamamoto, Yuji; Hayashi, Yoshimitsu; Sato, Shuichi

    2012-03-01

    In badminton, knees opposite to the racket-hand side received anterior cruciate ligament (ACL) injuries during single-leg landing after overhead stroke. Most of them occurred in the backhand-side of the rear court. Comparing lower limb biomechanics during single-leg landing after overhead stroke between the forehand-side and backhand-side court may help explain the different injury rates depending on court position. The knee kinematics and kinetics during single-leg landing after overhead stroke following back-stepping were different between the forehand-side and backhand-side court. Controlled laboratory study. Hip, knee and ankle joint kinematic and knee kinetic data were collected for 17 right-handed female college badminton players using a 3-dimensional motion analysis system. Subjects performed single-left-legged landing after an overhead stroke following left and right back-stepping. The kinematic and kinetic data of the left lower extremities during landing were measured and compared between left and right back-steps. Hip flexion and abduction and knee valgus at the initial contact, hip and knee flexion and knee valgus at the maximum knee flexion and the maximum knee valgus moment were significantly larger for the left back-step than the right back-step (p<0.05). Significant differences in joint kinematics and kinetics of the lower extremity during single-leg landing after overhead stroke were observed between different back-step directions. Increased knee valgus angle and moment following back-stepping to the backhand-side might be related to the higher incidence of ACL injury during single-leg landing after overhead stroke.

  12. A 3D musculoskeletal model of the western lowland gorilla hind limb: moment arms and torque of the hip, knee and ankle

    OpenAIRE

    Goh, Colleen; Blanchard, Mary L.; Crompton, Robin H.; Gunther, Michael M.; Macaulay, Sophie; Bates, Karl T.

    2017-01-01

    Abstract Three?dimensional musculoskeletal models have become increasingly common for investigating muscle moment arms in studies of vertebrate locomotion. In this study we present the first musculoskeletal model of a western lowland gorilla hind limb. Moment arms of individual muscles around the hip, knee and ankle were compared with previously published data derived from the experimental tendon travel method. Considerable differences were found which we attribute to the different methodolog...

  13. Bracing of the Reconstructed and Osteoarthritic Knee during High Dynamic Load Tasks.

    Science.gov (United States)

    Hart, Harvi F; Crossley, Kay M; Collins, Natalie J; Ackland, David C

    2017-06-01

    Lateral compartment osteoarthritis accompanied by abnormal knee biomechanics is frequently reported in individuals with knee osteoarthritis after anterior cruciate ligament reconstruction (ACLR). The aim of this study was to evaluate changes in knee biomechanics produced by an adjusted and unadjusted varus knee brace during high dynamic loading activities in individuals with lateral knee osteoarthritis after ACLR and valgus malalignment. Nineteen participants who had undergone ACLR 5 to 20 yr previously and had symptomatic and radiographic lateral knee osteoarthritis with valgus malalignment were assessed. Quantitative motion analysis experiments were conducted during hopping, stair ascent, and descent under three test conditions: (i) no brace, (ii) unadjusted brace with sagittal plane support and neutral frontal plane alignment, and (iii) adjusted brace with sagittal plane support and varus realignment (valgus to neutral). Sagittal, frontal, and transverse plane knee kinematics, external joint moment, and angular impulse data were calculated. Relative to an unbraced knee, braced conditions significantly increased knee flexion and adduction angles during hopping (P = 0.003 and P = 0.005; respectively), stair ascent (P = 0.003 and P stair ascent (P = 0.008) and flexion moments during stair descent (P = 0.006). There were no significant differences between the adjusted and the unadjusted brace conditions (P > 0.05). A knee brace, with or without varus alignment, can modulate knee kinematics and external joint moments during hopping, stairs ascent, and descent in individuals with predominant lateral knee osteoarthritis after ACLR. Longer-term use of a brace may have implications in slowing osteoarthritis progression.

  14. A 3D musculoskeletal model of the western lowland gorilla hind limb: moment arms and torque of the hip, knee and ankle.

    Science.gov (United States)

    Goh, Colleen; Blanchard, Mary L; Crompton, Robin H; Gunther, Michael M; Macaulay, Sophie; Bates, Karl T

    2017-10-01

    Three-dimensional musculoskeletal models have become increasingly common for investigating muscle moment arms in studies of vertebrate locomotion. In this study we present the first musculoskeletal model of a western lowland gorilla hind limb. Moment arms of individual muscles around the hip, knee and ankle were compared with previously published data derived from the experimental tendon travel method. Considerable differences were found which we attribute to the different methodologies in this specific case. In this instance, we argue that our 3D model provides more accurate and reliable moment arm data than previously published data on the gorilla because our model incorporates more detailed consideration of the 3D geometry of muscles and the geometric constraints that exist on their lines-of-action about limb joints. Our new data have led us to revaluate the previous conclusion that muscle moment arms in the gorilla hind limb are optimised for locomotion with crouched or flexed limb postures. Furthermore, we found that bipedalism and terrestrial quadrupedalism coincided more regularly with higher moment arms and torque around the hip, knee and ankle than did vertical climbing. This indicates that the ability of a gorilla to walk bipedally is not restricted by musculoskeletal adaptations for quadrupedalism and vertical climbing, at least in terms of moment arms and torque about hind limb joints. © 2017 The Authors. Journal of Anatomy published by John Wiley & Sons Ltd on behalf of Anatomical Society.

  15. Knee Kinematics and Joint Moments During Stair Negotiation in Participants With Anterior Cruciate Ligament Deficiency and Reconstruction: A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Hajizadeh, Maryam; Hashemi Oskouei, Alireza; Ghalichi, Farzan; Sole, Gisela

    2016-06-01

    Biomechanical changes have been reported for patients with anterior cruciate ligament deficiency (ACLD) and anterior cruciate ligament (ACL reconstruction) (ACLR), likely due to loss of stability and changes in proprioception and neuromotor control. This review evaluated kinematics and kinetics of ACLD and ACLR knees, compared with those on the contralateral uninjured sides, as well as and those in asymptomatic controls during stair navigation. This is a systematic review and meta-analysis. Electronic database searches were conducted from their original available dates to January 2015. Studies that included participants with ACLD or ACLR and reported knee joint angles or moments during stair ascent or descent were included. Nine studies met the inclusion criteria, and the methodological quality of these was assessed with a modified Downs and Black checklist. Effect sizes for differences between injured leg and uninjured contralateral leg or controls were calculated, and meta-analyses were performed if two or more studies considered the same variable. Quality assessment showed an average (± standard deviation) of 70.3% ± 7.2%. Meta-analysis showed less knee flexion at initial contact for ACLR knees compared with that in contralateral knees during stair ascent, with a moderate effect size and minimal heterogeneity. Knees with ACLD showed less peak knee flexion compared with that on contralateral sides during stair ascent, with minimal heterogeneity. External knee flexion moments were lower for ACLR compared with those in controls and contralateral sides during ascent and descent, whereas these moments were decreased for the ACLD compared with controls only during ascent. Meta-analysis results exhibited moderate/high heterogeneity or small/trivial effect sizes. Differences for kinematics and kinetics for the ACL-injured knees indicate long-term compensatory and asymmetric movement patterns while ascending and descending stairs. Due to the heterogeneity as well as

  16. Knee Biomechanics During Jogging After Arthroscopic Partial Meniscectomy: A Longitudinal Study.

    Science.gov (United States)

    Hall, Michelle; Wrigley, Tim V; Metcalf, Ben R; Hinman, Rana S; Cicuttini, Flavia M; Dempsey, Alasdair R; Lloyd, David G; Bennell, Kim L

    2017-07-01

    Altered knee joint biomechanics is thought to play a role in the pathogenesis of knee osteoarthritis and has been reported in patients after arthroscopic partial meniscectomy (APM) while performing various activities. Longitudinally, understanding knee joint biomechanics during jogging may assist future studies to assess the implications of jogging on knee joint health in this population. To investigate knee joint biomechanics during jogging in patients 3 months after APM and a healthy control group at baseline and 2 years later at follow-up. Controlled laboratory study. Seventy-eight patients who underwent medial APM and 38 healthy controls underwent a 3-dimensional motion analysis during barefoot overground jogging at baseline. Sixty-four patients who underwent APM and 23 controls returned at follow-up. External peak moments (flexion and adduction) and the peak knee flexion angle during stance were evaluated for the APM leg, non-APM leg (nonoperated leg), and control leg. At baseline, the peak knee flexion angle was 1.4° lower in the APM leg compared with the non-APM leg ( P = .03). No differences were found between the moments in the APM leg compared with the control leg (all P > .05). However, the normalized peak knee adduction moment was 35% higher in the non-APM leg compared with the control leg ( P = .008). In the non-APM leg, the normalized peak knee adduction and flexion moments were higher compared with the APM leg by 16% and 10%, respectively, at baseline ( P ≤ .004). Despite the increase in the peak knee flexion moment in the APM leg compared with the non-APM leg ( P .05). Comparing the APM leg and control leg, no differences in knee joint biomechanics during jogging for the variables assessed were observed. Higher knee moments in the non-APM leg may have clinical implications for the noninvolved leg. Kinematic differences were small (~1.4°) and therefore of questionable clinical relevance. These results may facilitate future clinical research

  17. Design and Evaluation of a New Type of Knee Orthosis to Align the Mediolateral Angle of the Knee Joint with Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Amir Esrafilian

    2012-01-01

    Full Text Available Background. Osteoarthritis (OA is a disease which influences the performance of the knee joint. Moreover, the force and moments applied on the joint increase in contrast to normal subjects. Various types of knee orthoses have been designed to solve the mentioned problems. However, there are other problems in terms of distal migration during walking and the alignment of the orthosis which cannot be changed following the use of brace. Therefore, the main aim of the research was to design an orthosis to solve the aforementioned problems. Method. A new type of knee orthosis was designed with a modular structure. Two patients with knee OA participated in this research project. The force applied on the foot, moment transmitted through the knee joint, and spatiotemporal gait parameters were measured by use of a motion analysis system. Results. The results of the research showed that the adduction moment applied on the knee joint decreased while subjects walked with the new knee orthosis (P-value < 0.05. Conclusion. The new design of the knee brace can be used as an effective treatment to decrease the loads applied on the knee joint and to improve the alignment whilst walking.

  18. Effect of exercise-induced enhancement of the leg-extensor muscle-tendon unit capacities on ambulatory mechanics and knee osteoarthritis markers in the elderly.

    Science.gov (United States)

    Karamanidis, Kiros; Oberländer, Kai Daniel; Niehoff, Anja; Epro, Gaspar; Brüggemann, Gert-Peter

    2014-01-01

    Leg-extensor muscle weakness could be a key component in knee joint degeneration in the elderly because it may result in altered muscular control during locomotion influencing the mechanical environment within the joint. This work aimed to examine whether an exercise-induced enhancement of the triceps surae (TS) and quadriceps femoris (QF) muscle-tendon unit (MTU) capacities would affect mechanical and biological markers for knee osteoarthritis in the elderly. Twelve older women completed a 14-week TS and QF MTU exercise intervention, which had already been established as increasing muscle strength and tendon stiffness. Locomotion mechanics and serum cartilage oligomeric matrix protein (COMP) levels were examined during incline walking. MTU mechanical properties were assessed using simultaneously ultrasonography and dynamometry. Post exercise intervention, the elderly had higher TS and QF contractile strength and tendon-aponeurosis stiffness. Regarding the incline gait task, the subjects demonstrated a lower external knee adduction moment and lower knee adduction angular impulse during the stance phase post-intervention. Furthermore, post-intervention compared to pre-intervention, the elderly showed lower external hip adduction moment, but revealed higher plantarflexion pushoff moment. The changes in the external knee adduction moment were significantly correlated with the improvement in ankle pushoff function. Serum COMP concentration increased in response to the 0.5-h incline walking exercise with no differences in the magnitude of increment between pre- and post-intervention. This work emphasizes the important role played by the ankle pushoff function in knee joint mechanical loading during locomotion, and may justify the inclusion of the TS MTU in prevention programs aiming to positively influence specific mechanical markers for knee osteoarthritis in the elderly. However, the study was unable to show that COMP is amenable to change in the elderly following a

  19. Relationships between in vivo dynamic knee joint loading, static alignment and tibial subchondral bone microarchitecture in end-stage knee osteoarthritis.

    Science.gov (United States)

    Roberts, B C; Solomon, L B; Mercer, G; Reynolds, K J; Thewlis, D; Perilli, E

    2018-04-01

    To study, in end-stage knee osteoarthritis (OA) patients, relationships between indices of in vivo dynamic knee joint loads obtained pre-operatively using gait analysis, static knee alignment, and the subchondral trabecular bone (STB) microarchitecture of their excised tibial plateau quantified with 3D micro-CT. Twenty-five knee OA patients scheduled for total knee arthroplasty underwent pre-operative gait analysis. Mechanical axis deviation (MAD) was determined radiographically. Following surgery, excised tibial plateaus were micro-CT-scanned and STB microarchitecture analysed in four subregions (anteromedial, posteromedial, anterolateral, posterolateral). Regional differences in STB microarchitecture and relationships between joint loading and microarchitecture were examined. STB microarchitecture differed among subregions (P knee adduction moment (KAM) and internal rotation moment (|r|-range: 0.54-0.74). When controlling for walking speed, KAM and MAD, the ERM explained additional 11-30% of the variations in anteromedial BV/TV and medial-to-lateral BV/TV ratio (R 2  = 0.59, R 2  = 0.69, P knee joint loading indices in end-stage knee OA patients. Particularly, anteromedial BV/TV correlates strongest with ERM, whereas medial-to-lateral BV/TV ratio correlates strongest with indicators of medial-to-lateral joint loading (MAD, KAM) and rotational moments. However, associations with ERM should be interpreted with caution. Copyright © 2018 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  20. Alterations in knee joint laxity during the menstrual cycle in healthy women leads to increases in joint loads during selected athletic movements.

    Science.gov (United States)

    Park, Sang-Kyoon; Stefanyshyn, Darren J; Ramage, Barbara; Hart, David A; Ronsky, Janet L

    2009-06-01

    It has been speculated that the hormonal cycle may be correlated with higher incidence of ACL injury in female athletes, but results have been very contradictory. Knee joint loads are influenced by knee joint laxity (KJL) during the menstrual cycle. Controlled laboratory study. Serum samples and KJL were assessed at the follicular, ovulation, and luteal phases in 26 women. Knee joint mechanics (angle, moment, and impulse) were measured and compared at the same intervals. Each of the 26 subjects had a value for knee laxity at each of the 3 phases of their cycle, and these were ordered and designated low, medium, and high for that subject. Knee joint mechanics were then compared between low, medium, and high laxity. No significant differences in knee joint mechanics were found across the menstrual cycle (no phase effect). However, an increase in KJL was associated with higher knee joint loads during movement (laxity effect). A 1.3-mm increase in KJL resulted in an increase of approximately 30% in adduction impulse in a cutting maneuver, an increase of approximately 20% in knee adduction moment, and a 20% to 45% increase in external rotation loads during a jumping and stopping task (P knee joint loading during movements. Clinical Relevance Our findings will be beneficial for researchers in the development of more effective ACL injury prevention programs.

  1. Effect of rocker-soled shoes on parameters of knee joint load in knee osteoarthritis.

    Science.gov (United States)

    Madden, Elizabeth G; Kean, Crystal O; Wrigley, Tim V; Bennell, Kim L; Hinman, Rana S

    2015-01-01

    This study evaluated the immediate effects of rocker-soled shoes on parameters of the knee adduction moment (KAM) and pain in individuals with knee osteoarthritis (OA). Three-dimensional gait analysis was performed on 30 individuals (mean (SD): age, 61 (7) yr; 15 (50%) male) with radiographic and symptomatic knee OA under three walking conditions in a randomized order: i) wearing rocker-soled shoes (Skechers Shape-ups), ii) wearing non-rocker-soled shoes (ASICS walking shoes), and iii) barefoot. Peak KAM and KAM angular impulse were measured as primary indicators of knee load distribution. Secondary measures included the knee flexion moment (KFM) and knee pain during walking. Peak KAM was significantly lower when wearing the rocker-soled shoes compared with that when wearing the non-rocker-soled shoes (mean difference (95% confidence interval), -0.27 (-0.42 to -0.12) N·m/BW × Ht%; P < 0.001). Post hoc tests revealed no significant difference in KAM impulse between rocker-soled and non-rocker-soled shoe conditions (P = 0.13). Both peak KAM and KAM impulse were significantly higher during both shoe conditions compared with those during the barefoot condition (P < 0.001). There were no significant differences in KFM (P = 0.36) or knee pain (P = 0.89) between conditions. Rocker-soled shoes significantly reduced peak KAM when compared with non-rocker-soled shoes, without a concomitant change in KFM, and thus may potentially reduce medial knee joint loading. However, KAM parameters in the rocker-soled shoes remained significantly higher than those during barefoot walking. Wearing rocker-soled shoes did not have a significant immediate effect on walking pain. Further research is required to evaluate whether rocker-soled shoes can influence symptoms and progression of knee OA with prolonged wear.

  2. The relationship between pain and dynamic knee joint loading in knee osteoarthritis varies with radiographic disease severity. A cross sectional study.

    Science.gov (United States)

    Henriksen, Marius; Aaboe, Jens; Bliddal, Henning

    2012-08-01

    In a cross sectional study, we investigated the relationships between knee pain and mechanical loading across the knee, as indicated by the external knee adduction moment (KAM) during walking in patients with symptomatic knee OA who were distinguished by different radiographic disease severities. Data from 137 symptomatic medial knee OA patients were used. Based on Kellgren/Lawrence (K/L) grading, the patients were divided into radiographically less severe (K/L ≤ 2, n=68) or severe (K/L>2, n=69) medial knee OA. Overall knee pain was rated on a 10 cm visual analog scale, and peak KAM and KAM impulses were obtained from gait analyses. Mixed linear regression analyses were performed with KAM variables as the outcome, and pain and disease severity as independent variables, adjusting for age, gender, and walking speed. In adjusted analyses, less severe patients demonstrated negative relationships between pain intensities and dynamic loading. The severe patient group showed no relationship between pain intensity and peak KAM, and a positive relationship between pain intensity and KAM impulse. In radiographically less severe knee OA, the negative relationships between pain intensity and dynamic knee joint loading indicate a natural reaction to pain, which will limit the stress on the joint. In contrast, either absent or positive relationships between pain and dynamic loading in severe OA may lead to overuse and accelerated disease progression. These findings may have a large potential interest for strategies of treatment in knee OA. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. The influence of sex and obesity on gait biomechanics in people with severe knee osteoarthritis scheduled for arthroplasty.

    Science.gov (United States)

    Paterson, K L; Sosdian, L; Hinman, R S; Wrigley, T V; Kasza, J; Dowsey, M; Choong, P; Bennell, K L

    2017-11-01

    Sex and body mass may influence knee biomechanics associated with poor total knee arthroplasty (TKA) outcomes for knee osteoarthritis (OA). This study aimed to determine if gait differed between men and women, and overweight and class I obese patients with severe knee OA awaiting TKA. 34 patients with severe knee OA (average age 70.0 (SD 7.2) years, body mass index 30.3 (4.1kg/m 2 )) were recruited from a TKA waiting list. Three-dimensional gait analysis was performed at self-selected walking speed. Comparisons were made between men and women, and overweight (body mass index (BMI) 25.0-29.9kg/m 2 ) and class I obese (BMI 30.0-34.9kg/m 2 ) participants. Biomechanical outcomes included absolute and body size-adjusted peak knee adduction moment (KAM), KAM impulse, peak knee flexion moment, as well as peak knee flexion and varus-valgus angles, peak varus-valgus thrust, and peak vertical ground reaction force (GRF). Men had a higher absolute peak KAM, KAM impulse and peak GRF compared to women, and this sex-difference in frontal plane moments remained after adjusting for body size. However, when additionally adjusting for static knee alignment, differences disappeared. Knee biomechanics were similar between obesity groups after adjusting for the greater body weight of those with class I obesity. Men had greater KAM and KAM impulse even after adjustment for body size; however adjustment for their more varus knees removed this difference. Obesity group did not influence knee joint kinematics or moments. This suggests sex- and obesity-differences in these variables may not be associated with TKA outcomes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Comparison of neuromuscular and quadriceps strengthening exercise in the treatment of varus malaligned knees with medial knee osteoarthritis: a randomised controlled trial protocol

    Directory of Open Access Journals (Sweden)

    Bennell Kim L

    2011-12-01

    Full Text Available Abstract Background Osteoarthritis of the knee involving predominantly the medial tibiofemoral compartment is common in older people, giving rise to pain and loss of function. Many people experience progressive worsening of the disease over time, particularly those with varus malalignment and increased medial knee joint load. Therefore, interventions that can reduce excessive medial knee loading may be beneficial in reducing the risk of structural progression. Traditional quadriceps strengthening can improve pain and function in people with knee osteoarthritis but does not appear to reduce medial knee load. A neuromuscular exercise program, emphasising optimal alignment of the trunk and lower limb joints relative to one another, as well as quality of movement performance, while dynamically and functionally strengthening the lower limb muscles, may be able to reduce medial knee load. Such a program may also be superior to traditional quadriceps strengthening with respect to improved pain and physical function because of the functional and dynamic nature. This randomised controlled trial will investigate the effect of a neuromuscular exercise program on medial knee joint loading, pain and function in individuals with medial knee joint osteoarthritis. We hypothesise that the neuromuscular program will reduce medial knee load as well as pain and functional limitations to a greater extent than a traditional quadriceps strengthening program. Methods/Design 100 people with medial knee pain, radiographic medial compartment osteoarthritis and varus malalignment will be recruited and randomly allocated to one of two 12-week exercise programs: quadriceps strengthening or neuromuscular exercise. Each program will involve 14 supervised exercise sessions with a physiotherapist plus four unsupervised sessions per week at home. The primary outcomes are medial knee load during walking (the peak external knee adduction moment from 3D gait analysis, pain, and self

  5. Gait adaptations with aging in healthy participants and people with knee-joint osteoarthritis.

    Science.gov (United States)

    Duffell, Lynsey D; Jordan, Stevan J; Cobb, Justin P; McGregor, Alison H

    2017-09-01

    The relationship between age and gait characteristics in people with and without medial compartment osteoarthritis (OA) remains unclear. We aimed to characterize this relationship and to relate biomechanical and structural parameters in a subset of OA patients. Twenty five participants with diagnosed unilateral medial knee OA and 84 healthy participants, with no known knee pathology were recruited. 3D motion capture was used to analyse sagittal and coronal plane gait parameters while participants walked at a comfortable speed. Participants were categorized according to age (18-30, 31-59 and 60+ years), and those with and without OA were compared between and within age groups. In a subset of OA patients, clinically available Computed Tomography images were used to assess joint structure. Differences in coronal plane kinematics at the hip and knee were noted in participants with OA particularly those who were older compared with our healthy controls, as well as increased knee moments. Knee adduction moment correlated with structural parameters in the subset of OA patients. Increased knee moments and altered kinematics were observed in older participants presenting with OA only, which seem to be related to morphological changes in the joint due to OA, as opposed to being related to the initial cause of medial knee OA. Copyright © 2017. Published by Elsevier B.V.

  6. Evaluation of factors that affect hip moment impulse during gait: A systematic review.

    Science.gov (United States)

    Inai, Takuma; Takabayashi, Tomoya; Edama, Mutsuaki; Kubo, Masayoshi

    2018-03-01

    Decreasing the daily cumulative hip moments in the frontal and sagittal planes may lower the risk of hip osteoarthritis. Therefore, it may be important to evaluate factors that affect hip moment impulse during gait. It is unclear what factors affect hip moment impulse during gait. This systematic review aimed to evaluate different factors that affect hip moment impulse during gait in healthy adults and patients with hip osteoarthritis. Four databases (Scopus, ScienceDirect, PubMed, and PEDro) were searched up to August 2017 to identify studies that examined hip moment impulse during gait. Data extracted for analysis included the sample size, age, height, body mass, type of intervention, and main findings. After screening, 10 of the 975 studies identified were included in our analysis. Several factors, including a rocker bottom shoe, FitFlop™ sandals, ankle push-off, posture, stride length, body-weight unloading, a rollator, walking poles, and a knee brace, were reviewed. The main findings were as follows: increasing ankle push-off decreased both the hip flexion and extension moment impulses; body-weight unloading decreased both the hip extension and adduction moment impulses; the FitFlop™ sandal increased the sum of the hip flexion and extension moment impulses; long strides increased the hip extension moment impulse; and the use of a knee brace increased hip flexion moment impulse. Of note, none of the eligible studies included patients with hip osteoarthritis. The hip moment impulses can be modified by person-specific factors (ankle push-off and long strides) and external factors (body-weight unloading and use of the FitFlop™ sandals and a knee brace). Effects on the progression of hip osteoarthritis remain to be evaluated. Copyright © 2018 Elsevier B.V. All rights reserved.

  7. The effects of neuromuscular exercise on medial knee joint load post-arthroscopic partial medial meniscectomy: 'SCOPEX', a randomised control trial protocol.

    Science.gov (United States)

    Hall, Michelle; Hinman, Rana S; Wrigley, Tim V; Roos, Ewa M; Hodges, Paul W; Staples, Margaret; Bennell, Kim L

    2012-11-27

    Meniscectomy is a risk factor for knee osteoarthritis, with increased medial joint loading a likely contributor to the development and progression of knee osteoarthritis in this group. Therefore, post-surgical rehabilitation or interventions that reduce medial knee joint loading have the potential to reduce the risk of developing or progressing osteoarthritis. The primary purpose of this randomised, assessor-blind controlled trial is to determine the effects of a home-based, physiotherapist-supervised neuromuscular exercise program on medial knee joint load during functional tasks in people who have recently undergone a partial medial meniscectomy. 62 people aged 30-50 years who have undergone an arthroscopic partial medial meniscectomy within the previous 3 to 12 months will be recruited and randomly assigned to a neuromuscular exercise or control group using concealed allocation. The neuromuscular exercise group will attend 8 supervised exercise sessions with a physiotherapist and will perform 6 exercises at home, at least 3 times per week for 12 weeks. The control group will not receive the neuromuscular training program. Blinded assessment will be performed at baseline and immediately following the 12-week intervention. The primary outcomes are change in the peak external knee adduction moment measured by 3-dimensional analysis during normal paced walking and one-leg rise. Secondary outcomes include the change in peak external knee adduction moment during fast pace walking and one-leg hop and change in the knee adduction moment impulse during walking, one-leg rise and one-leg hop, knee and hip muscle strength, electromyographic muscle activation patterns, objective measures of physical function, as well as self-reported measures of physical function and symptoms and additional biomechanical parameters. The findings from this trial will provide evidence regarding the effect of a home-based, physiotherapist-supervised neuromuscular exercise program on medial knee

  8. The effects of neuromuscular exercise on medial knee joint load post-arthroscopic partial medial meniscectomy: ‘SCOPEX’ a randomised control trial protocol

    Science.gov (United States)

    2012-01-01

    Background Meniscectomy is a risk factor for knee osteoarthritis, with increased medial joint loading a likely contributor to the development and progression of knee osteoarthritis in this group. Therefore, post-surgical rehabilitation or interventions that reduce medial knee joint loading have the potential to reduce the risk of developing or progressing osteoarthritis. The primary purpose of this randomised, assessor-blind controlled trial is to determine the effects of a home-based, physiotherapist-supervised neuromuscular exercise program on medial knee joint load during functional tasks in people who have recently undergone a partial medial meniscectomy. Methods/design 62 people aged 30–50 years who have undergone an arthroscopic partial medial meniscectomy within the previous 3 to 12 months will be recruited and randomly assigned to a neuromuscular exercise or control group using concealed allocation. The neuromuscular exercise group will attend 8 supervised exercise sessions with a physiotherapist and will perform 6 exercises at home, at least 3 times per week for 12 weeks. The control group will not receive the neuromuscular training program. Blinded assessment will be performed at baseline and immediately following the 12-week intervention. The primary outcomes are change in the peak external knee adduction moment measured by 3-dimensional analysis during normal paced walking and one-leg rise. Secondary outcomes include the change in peak external knee adduction moment during fast pace walking and one-leg hop and change in the knee adduction moment impulse during walking, one-leg rise and one-leg hop, knee and hip muscle strength, electromyographic muscle activation patterns, objective measures of physical function, as well as self-reported measures of physical function and symptoms and additional biomechanical parameters. Discussion The findings from this trial will provide evidence regarding the effect of a home-based, physiotherapist

  9. The effects of neuromuscular exercise on medial knee joint load post-arthroscopic partial medial meniscectomy: ‘SCOPEX’ a randomised control trial protocol

    Directory of Open Access Journals (Sweden)

    Hall Michelle

    2012-11-01

    Full Text Available Abstract Background Meniscectomy is a risk factor for knee osteoarthritis, with increased medial joint loading a likely contributor to the development and progression of knee osteoarthritis in this group. Therefore, post-surgical rehabilitation or interventions that reduce medial knee joint loading have the potential to reduce the risk of developing or progressing osteoarthritis. The primary purpose of this randomised, assessor-blind controlled trial is to determine the effects of a home-based, physiotherapist-supervised neuromuscular exercise program on medial knee joint load during functional tasks in people who have recently undergone a partial medial meniscectomy. Methods/design 62 people aged 30–50 years who have undergone an arthroscopic partial medial meniscectomy within the previous 3 to 12 months will be recruited and randomly assigned to a neuromuscular exercise or control group using concealed allocation. The neuromuscular exercise group will attend 8 supervised exercise sessions with a physiotherapist and will perform 6 exercises at home, at least 3 times per week for 12 weeks. The control group will not receive the neuromuscular training program. Blinded assessment will be performed at baseline and immediately following the 12-week intervention. The primary outcomes are change in the peak external knee adduction moment measured by 3-dimensional analysis during normal paced walking and one-leg rise. Secondary outcomes include the change in peak external knee adduction moment during fast pace walking and one-leg hop and change in the knee adduction moment impulse during walking, one-leg rise and one-leg hop, knee and hip muscle strength, electromyographic muscle activation patterns, objective measures of physical function, as well as self-reported measures of physical function and symptoms and additional biomechanical parameters. Discussion The findings from this trial will provide evidence regarding the effect of a home

  10. Gait changes in patients with knee osteoarthritis are replicated by experimental knee pain

    DEFF Research Database (Denmark)

    Henriksen, Marius; Nielsen, Thomas Graven; Aaboe, Jens

    2010-01-01

    Medial knee osteoarthritis (OA) is characterized by pain and associated with abnormal knee moments during walking. The relationship between knee OA pain and gait changes remains to be clarified, and a better understanding of this link could advance the treatment and prevention of disease...... progression. This study investigated changes in knee moments during walking following experimental knee pain in healthy volunteers, and whether these changes replicated the joint moments observed in medial knee OA patients....

  11. Kinematic and kinetic analysis of the knee joint before and after a PCL retaining total knee replacement during gait and single step ascent.

    Science.gov (United States)

    Apostolopoulos, Alexandros; Lallos, Stergios; Mastrokalos, Dimitrios; Michos, Ioannis; Darras, Nikolaos; Tzomaki, Magda; Efstathopoulos, Nikolaos

    2011-01-01

    The objective of this study was to capture and analyze the kinetics and kinematics and determine the functional performance of the osteoarthritic knee after a posterior cruciate ligament (PCL) retaining total knee arthroplasty. Kinematic and kinetic gait analysis of level walking was performed in 20 subjects (12 female and 8 male) with knee ostoarthritis. These patients were free of any neurological diseases that could affect their normal gait. Mean age was 69.6 ± 6.6 years; mean height was 157.6 cm ± 7.6 cm; and mean weight was 77.2 ± 12.1 kg. Full body gait analyses were performed using the BIOKIN 3D motion analysis system before and 9 months after total knee arthroplasty procedures. Single-step ascending kinetic analyses and plantar pressure distribution analyses were also performed for all subjects. International Knee Society Scores (IKSSs) were also assessed pre- and postoperatively. Significant increases were noted postoperatively in average cadence (preoperative mean = 99.26, postoperative mean = 110.5; p knee adduction moment were also reported postoperatively. All patients showed a significant improvement of knee kinetics and kinematics after a PCL retaining total knee arthroplasty. Significant differences were found in the cadence, step length, stride length, and walk velocity postoperatively. IKSSs also significantly improved. Further research is warranted to determine the clinical relevance of these findings.

  12. Potential factors associated with knee pain in cyclists: a systematic review

    Directory of Open Access Journals (Sweden)

    Bini RR

    2018-05-01

    Full Text Available Rodrigo Rico Bini, Alice Flores Bini La Trobe Rural Health School, La Trobe University, Flora Hill Campus, Bendigo, VIC, Australia Abstract: The potential factors associated with overuse injuries and pain in cyclists that are supported by evidence remain unclear. Our study aimed at assessing, using a systematic search of the most updated evidence, the main factors related to overuse knee-related pain and/or injuries in cyclists. The search assessed any potential mechanism related to knee pain or injury that could be used in the clinical practice. Databases were searched (i.e., PubMed, Scopus, Web of Science, and EBSCO. Studies were included if they presented results from original studies. They had to include, preferably but not limited to, recreational and/or competitive cyclists with or without knee pain. Quality of articles was assessed. Eleven articles were deemed eligible for full text appraisal. Studies involved generally the assessment of biomechanical outcomes associated with knee pain in cyclists. Overall, studies showed that cyclists with knee pain present larger knee adduction and larger ankle dorsiflexion and differences in activation for hamstrings and quadriceps muscles. Unclear results were observed for knee moments and no differences were observed for knee flexion angle, tibiofemoral and patellofemoral forces. It is important to state that varied types of knee pain were mixed in most studies, with 2 focused on anterior-related pain. Cyclists with overuse-related pain or injuries on their knees presented an increased medial projection of their knees and an altered activation of the Vastus Medialis and Vastus Lateralis muscles. However, this limited evidence is based on retrospective studies comparing cyclists with and without pain, which limits the conclusion on how cyclists develop knee pain and what are the main options for treatment of knee pain. Keywords: injury, cycling, overuse, biomechanics

  13. Combined versus individual effects of a valgus knee brace and lateral wedge foot orthotic during stair use in patients with knee osteoarthritis.

    Science.gov (United States)

    Moyer, Rebecca; Birmingham, Trevor; Dombroski, Colin; Walsh, Robert; Giffin, J Robert

    2017-05-01

    The aim of this study was to investigate the combined and individual biomechanical effects of a valgus knee brace and a lateral wedge foot orthotic during stair ascent and descent in patients with knee osteoarthritis (OA). Thirty-five patients with varus alignment and medial knee OA were prescribed a custom valgus knee brace and lateral wedge foot orthotic. Knee angles and moments in the frontal and sagittal planes were determined from 3D gait analysis completed under four randomized conditions: (1) control (no knee brace or foot orthotic), (2) knee brace, (3) foot orthotic, and (4) combined knee brace and foot orthotic. Additional measures included the vertical ground reaction force, trunk lean, toe out and gait speed. During the combined use of a knee brace and foot orthotic, significant decreases in the knee adduction angle (2.17, 95%CI: 0.50-3.84, p=0.013) and 2nd peak EKAM (0.35, 95%CI: 0.17-0.52, pstair descent; and significant increases in the EKFM were observed during stair ascent (0.54, 95%CI: 0.30-0.78, pstair descent compared to ascent, except for toe out. Findings suggest greater effects on gait when both knee brace and foot orthotic are used together, resulting in a more normal gait pattern. However, whether or not a true change in knee joint load can be inferred when using these orthoses remains unclear. Further research is required to determine the clinical importance of the observed changes. Copyright © 2017. Published by Elsevier B.V.

  14. An Evaluation of the Correlation between the Free Moments Applied on the Lower Extremity and the Knee Extensor Mechanism Force in Pronated Foot Subjects during the Stance Phase of Gait

    Directory of Open Access Journals (Sweden)

    Farzaneh Yazdani

    2016-12-01

    Full Text Available Background: Due to the rotatory nature of the excessive subtalar pronation and the possible impairment of the tibial rotation-knee flexion mechanism, changes of the free moment (FM and changes of the extensor mechanism force are expected in hyper-pronated foot subjects. The purpose of this study was to evaluate the correlation between the FM applied on the lower extremity and the knee extensor mechanism force in subjects with flexible pronated feet. Methods: Fifteen asymptomatic female subjects (21.32±1.66 y, 56.30±6.08 kg, 159±6.3 cm participated in the study. Excessive subtalar pronation was determined by measuring the resting calcaneal stance position (RCSP in the frontal plane during weight bearing. A neutrally aligned foot was defined as having an RCSP between 2° of inversion and 2° of eversion. On the other hand, a flat foot had an RCSP of more than or equal to 4° of eversion. Both kinetic and kinematic data were collected using a six-camera motion analysis system and a single force plate. Three successful barefoot walking trials were recorded at selfselected speeds. The extensor mechanism force and the adductory component of the free moment (ADD FM were calculated. The correlation between the ADD FM and the knee extensor mechanism force was examined using the Pearson correlation test. Results: The Pearson correlation analysis showed a high positive correlation between the ADD FM and the extensor mechanism force (r=0.917, P<0.001. Conclusion: Excessive subtalar pronation, along with a possible impairment of the tibial rotation-knee flexion mechanism, may affect the extensor mechanism force at the knee joint. From a clinical perspective, the possible biomechanical linkage between the knee and the foot complex in the physical examination and treatment of patients should be considered.

  15. Clinical and biomechanical assessment of patella resurfacing in total knee arthroplasty.

    Science.gov (United States)

    Berti, Lisa; Benedetti, Maria Grazia; Ensini, Andrea; Catani, Fabio; Giannini, Sandro

    2006-07-01

    Currently there is a limited understanding of the factors influencing range of motion by comparing patellar resurfacing vs non-resurfacing in total knee arthroplasty during activities of daily living. A recent meta-analysis of patellar replacement confirms better outcome with patella resurfacing; however, the result can be influenced by many other factors, such as: component design, surgeon experience, and technical aspects of the surgery. This study compares the biomechanics of the knee in patients after total knee arthroplasty with and without patellar resurfacing during stair climbing. Forty-seven patients with total knee arthroplasty were assessed at the mean follow-up of 24 months. In all of them a posterior stabilised fixed bearing prosthesis (Optetrak PS, Exactech) was implanted. Twenty-six patients were treated without patellar resurfacing and 21 with patellar resurfacing. Clinical evaluations were performed using the International Knee Society and the Hospital for Special Surgery scores. Ten patients with patellar resurfacing and 10 patients without patellar resurfacing were also studied with motion analysis during stair climbing; 10 healthy subjects were studied for statistical comparison. Clinical passive knee flexion, International Knee Society Function and Hospital for Special Surgery scores were significantly higher in the patellar resurfacing group. During stair climbing, active knee joint range of motion during the stance phase was greater in patients with patellar resurfacing. The maximum adduction moment was significantly higher in the group without patellar resurfacing. Patients with patellar resurfacing demonstrated better clinical scores, and kinematic and kinetic data while ascending stairs.

  16. MUSCLE ACTIVITY RESPONSE TO EXTERNAL MOMENT DURING SINGLE-LEG DROP LANDING IN YOUNG BASKETBALL PLAYERS: THE IMPORTANCE OF BICEPS FEMORIS IN REDUCING INTERNAL ROTATION OF KNEE DURING LANDING

    Directory of Open Access Journals (Sweden)

    Meguru Fujii

    2012-06-01

    Full Text Available Internal tibial rotation with the knee close to full extension combined with valgus collapse during drop landing generally results in non-contact anterior cruciate ligament (ACL injury. The purpose of this study was to investigate the relationship between internal rotation of the knee and muscle activity from internal and external rotator muscles, and between the internal rotation of knee and externally applied loads on the knee during landing in collegiate basketball players. Our hypothesis was that the activity of biceps femoris muscle would be an important factor reducing internal knee rotation during landing. The subjects were 10 collegiate basketball students: 5 females and 5 males. The subjects performed a single-leg drop landing from a 25-cm height. Femoral and tibial kinematics were measured using a 3D optoelectronic tracking system during the drop landings, and then the knee angular motions were determined. Ground reaction forces and muscle activation patterns (lateral hamstring and medial hamstring were simultaneously measured and computed. Results indicated that lower peak internal tibial rotation angle at the time of landing was associated with greater lateral hamstring activity (r = -0.623, p < 0.001. When gender was considered, the statistically significant correlation remained only in females. There was no association between the peak internal tibial rotation angle and the knee internal rotation moment. Control of muscle activity in the lateral to medial hamstring would be an important factor in generating sufficient force to inhibit excessive internal rotation during landing. Strengthening the biceps femoris might mitigate the higher incidence of non-contact ACL injury in female athletes

  17. Non-Sagittal Knee Joint Kinematics and Kinetics during Gait on Level and Sloped Grounds with Unicompartmental and Total Knee Arthroplasty Patients

    Science.gov (United States)

    Komnik, Igor; David, Sina; Weiss, Stefan; Potthast, Wolfgang

    2016-01-01

    After knee arthroplasty (KA) surgery, patients experience abnormal kinematics and kinetics during numerous activities of daily living. Biomechanical investigations have focused primarily on level walking, whereas walking on sloped surfaces, which is stated to affect knee kinematics and kinetics considerably, has been neglected to this day. This study aimed to analyze over-ground walking on level and sloped surfaces with a special focus on transverse and frontal plane knee kinematics and kinetics in patients with KA. A three-dimensional (3D) motion analysis was performed by means of optoelectronic stereophogrammetry 1.8 ± 0.4 years following total knee arthroplasty (TKA) and unicompartmental arthroplasty surgery (UKA). AnyBody™ Modeling System was used to conduct inverse dynamics. The TKA group negotiated the decline walking task with reduced peak knee internal rotation angles compared with a healthy control group (CG). First-peak knee adduction moments were diminished by 27% (TKA group) and 22% (UKA group) compared with the CG during decline walking. No significant differences were detected between the TKA and UKA groups, regardless of the locomotion task. Decline walking exposed apparently more abnormal knee frontal and transverse plane adjustments in KA patients than level walking compared with the CG. Hence, walking on sloped surfaces should be included in further motion analysis studies investigating KA patients in order to detect potential deficits that might be not obvious during level walking. PMID:28002437

  18. Mechanical and physiological factors in knee joint contact mechanics

    DEFF Research Database (Denmark)

    Mølgaard, Carsten

    conservative treatment modalities also increases. The aim of this thesis was to 1) identify relationships between footwear and laterally wedged insoles in a healthy group, 2) to evaluate the mechanical and physiological factors of experimental pain when introducing a laterally wedged insoles to otherwise...... not to the level of healthy matched controls. In conclusion, although similar reductions can be achieved by choice of shoe design the difference between a neutral running shoe and Oxford leather shoes are similar in magnitude compared to the effect of lateral wedges in any type of shoe. Experimental pain does...... not seem to change the effect of lateral wedges independently. The knee adduction moment in patients 3-5 years after a medial arthroscopic partial meniscectomy was at a similar level to what is observed with advanced knee osteoarthritis. Therefore, laterally wedged insoles should be considered part...

  19. DYNAMIC HIP ADDUCTION, ABDUCTION AND ABDOMINAL EXERCISES FROM THE HOLMICH GROIN-INJURY PREVENTION PROGRAM ARE INTENSE ENOUGH TO BE CONSIDERED STRENGTHENING EXERCISES - A CROSS-SECTIONAL STUDY

    DEFF Research Database (Denmark)

    Krommes, Kasper; Bandholm, Thomas; Jakobsen, Markus D

    2017-01-01

    and external obliques during isometric adduction against a football placed between the ankles (IBA), isometric adduction against a football placed between the knees (IBK), folding knife (FK), cross-country skiing on one leg (CCS), adduction partner (ADP) and abduction partner (ABP). The EMG-signals were...

  20. Kinetics features changes before and after intra-articular hyaluronic acid injections in patients with knee osteoarthritis.

    Science.gov (United States)

    Tang, Alice Chu-Wen; Tang, Simon Fuk-Tan; Hong, Wei-Hsien; Chen, Hsieh-Ching

    2015-02-01

    To examine the kinetic features in patients with knee osteoarthritis (OA) after intra-articular hyaluronic acid (IAHA) injections in different time periods. A single group repeated measures study. Gait laboratory in a tertiary hospital. Twenty-five subjects with bilateral symptomatic knee OA and 15 healthy control subjects. Gait analyses were performed in both control and OA groups before (baseline), and after the completion of IAHA injections (1 week, 3 months, and 6 months). Knee pain and functional indices were assessed using a visual analogue scale (VAS) and the Lequesne function Index (LI). Joint kinetic changes were analyzed in the frontal and sagittal planes with 6-camera motion analysis system and two AMTI force plates. VAS and LI scores were both improved in OA group after IAHA injections (pinjections (pinjections can provide significant pain relief and improvement in activity of daily living function for patients with knee OA. However, the reduction in pain and the increase in knee adduction moment may last up to 6 months. This may cause excessive loading on the knee joints, which may further accelerate the rate of knee degeneration. As a result, longer study time is needed to determine whether the observed kinetic findings in this study are associated with detrimental outcomes on the knee joints. © 2015 Elsevier B.V. All rights reserved.

  1. The effect of instruction in analgesic use compared with neuromuscular exercise on knee-joint load in patients with knee osteoarthritis: a randomized, single-blind, controlled trial.

    Science.gov (United States)

    Holsgaard-Larsen, A; Clausen, B; Søndergaard, J; Christensen, R; Andriacchi, T P; Roos, E M

    2017-04-01

    To investigate the effect of a neuro-muscular exercise (NEMEX) therapy program compared with instructions in optimized analgesics and anti-inflammatory drug use (PHARMA), on measures of knee-joint load in people with mild to moderate knee osteoarthritis (OA). We hypothesized that knee joint loading during walking would be reduced by NEMEX and potentially increased by PHARMA. Single-blind, randomized controlled trial (RCT) comparing NEMEX therapy twice a week with PHARMA. Participants with mild-to-moderate medial tibiofemoral knee OA were randomly allocated (1:1) to one of two 8-week treatments. Primary outcome was change in knee load during walking (Knee Index, a composite score from all three planes based on 3D movement analysis) after 8 weeks of intervention. Secondary outcomes were frontal plane peak knee adduction moment (KAM), Knee Injury and Osteoarthritis Outcome Scores (KOOS) and functional performance tests. Ninety three participants (57% women, 58 ± 8 years with a body mass index [BMI] of 27 ± 4 kg/m 2 (mean ± standard deviation [SD])) were randomized to NEMEX group (n = 47) or PHARMA (n = 46); data from 44 (94%) and 41 (89%) participants respectively, were available at follow-up. 49% of the participants in NEMEX and only 7% in PHARMA demonstrated good compliance. We found no difference in the primary outcome as evaluated by the Knee Index -0.07 [-0.17; 0.04] Nm/%BW HT. Secondary outcomes largely supported this finding. We found no difference in the primary outcome; knee joint load change during walking from a NEMEX program vs information on the recommended use of analgesics and anti-inflammatory drugs. ClinicalTrials.gov Identifier: NCT01638962 (July 3, 2012). Ethical Committee: S-20110153. Copyright © 2016 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  2. The effect on knee-joint load of instruction in analgesic use compared with neuromuscular exercise in patients with knee osteoarthritis: study protocol for a randomized, single-blind, controlled trial (the EXERPHARMA trial).

    Science.gov (United States)

    Clausen, Brian; Holsgaard-Larsen, Anders; Søndergaard, Jens; Christensen, Robin; Andriacchi, Thomas P; Roos, Ewa M

    2014-11-15

    Knee osteoarthritis (OA) is a mechanically driven disease, and it is suggested that medial tibiofemoral knee-joint load increases with pharmacologic pain relief, indicating that pharmacologic pain relief may be positively associated with disease progression. Treatment modalities that can both relieve pain and reduce knee-joint load would be preferable. The knee-joint load is influenced by functional alignment of the trunk, pelvis, and lower-limb segments with respect to the knee, as well as the ground-reaction force generated during movement. Neuromuscular exercise can influence knee load and decrease knee pain. It includes exercises to improve balance, muscle activation, functional alignment, and functional knee stability. The primary objective of this randomized controlled trial (RCT) is to investigate the efficacy of a NEuroMuscular EXercise (NEMEX) therapy program, compared with optimized analgesics and antiinflammatory drug use, on the measures of knee-joint load in people with mild to moderate medial tibiofemoral knee osteoarthritis. One hundred men and women with mild to moderate medial knee osteoarthritis will be recruited from general medical practices and randomly allocated (1:1) to one of two 8-week treatments, either (a) NEMEX therapy twice a week or (b) information on the recommended use of analgesics and antiinflammatory drugs (acetaminophen and oral NSAIDs) via a pamphlet and video materials. The primary outcome is change in knee load during walking (the Knee Index, a composite score of the first external peak total reaction moment on the knee joint from all three planes based on 3D movement analysis) after 8 weeks of intervention. Secondary outcomes include changes in the external peak knee-adduction moment and impulse and functional performance measures, in addition to changes in self-reported pain, function, health status, and quality of life. These findings will help determine whether 8 weeks of neuromuscular exercise is superior to optimized use

  3. Predicting dynamic knee joint load with clinical measures in people with medial knee osteoarthritis.

    Science.gov (United States)

    Hunt, Michael A; Bennell, Kim L

    2011-08-01

    Knee joint loading, as measured by the knee adduction moment (KAM), has been implicated in the pathogenesis of knee osteoarthritis (OA). Given that the KAM can only currently be accurately measured in the laboratory setting with sophisticated and expensive equipment, its utility in the clinical setting is limited. This study aimed to determine the ability of a combination of four clinical measures to predict KAM values. Three-dimensional motion analysis was used to calculate the peak KAM at a self-selected walking speed in 47 consecutive individuals with medial compartment knee OA and varus malalignment. Clinical predictors included: body mass; tibial angle measured using an inclinometer; walking speed; and visually observed trunk lean toward the affected limb during the stance phase of walking. Multiple linear regression was performed to predict KAM magnitudes using the four clinical measures. A regression model including body mass (41% explained variance), tibial angle (17% explained variance), and walking speed (9% explained variance) explained a total of 67% of variance in the peak KAM. Our study demonstrates that a set of measures easily obtained in the clinical setting (body mass, tibial alignment, and walking speed) can help predict the KAM in people with medial knee OA. Identifying those patients who are more likely to experience high medial knee loads could assist clinicians in deciding whether load-modifying interventions may be appropriate for patients, whilst repeated assessment of joint load could provide a mechanism to monitor disease progression or success of treatment. Copyright © 2010 Elsevier B.V. All rights reserved.

  4. The effects of fatigue and anticipation on the mechanics of the knee during cutting in female athletes.

    Science.gov (United States)

    Collins, Joseph D; Almonroeder, Thomas G; Ebersole, Kyle T; O'Connor, Kristian M

    2016-06-01

    Unanticipated cutting tasks which do not allow for pre-planning of a movement have been reported to promote knee mechanics which may increase the risk of anterior cruciate ligament injury. Fatigue has also been reported to have similar effects. Athletes must often perform unanticipated tasks when they are fatigued. Previous studies have reported that the effects of anticipation become more prominent as an athlete progresses through a fatigue protocol. However, the protocols previously utilized may not mimic the demands of sports participation. Three-dimensional knee joint kinematics and kinetics were collected from 13 female athletes while they performed a run-and-cut task, before and after completion of an intermittent shuttle run. Trials were further divided (pre-planned, unanticipated) to assess the effects of anticipation. There were no significant interactions between the effects of fatigue and anticipation for the peak knee angles or moments of the knee joint in any plane. Subjects did demonstrate a 68% increase in their peak knee abduction angles following completion of the intermittent shuttle run. Anticipation also had a significant effect on the mechanics of the knee in all planes. Most notably, there was a 23% increase in peak knee abduction angles and a 33% increase in the peak internal knee adduction moments. Both fatigue and anticipation promoted knee mechanics which are associated with an increased risk of knee injury. However, it does not appear that their effects combine when athletes are at a level of fatigue which is thought to reflect sports participation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Long-term use of minimal footwear on pain, self-reported function, analgesic intake, and joint loading in elderly women with knee osteoarthritis: A randomized controlled trial.

    Science.gov (United States)

    Trombini-Souza, Francis; Matias, Alessandra B; Yokota, Mariane; Butugan, Marco K; Goldenstein-Schainberg, Claudia; Fuller, Ricardo; Sacco, Isabel C N

    2015-12-01

    Efforts have been made to retard the progressive debilitating pain and joint dysfunction in patients with knee osteoarthritis. We aimed to evaluate the therapeutic effect of a low-cost minimalist footwear on pain, function, clinical and gait-biomechanical aspects of elderly women with knee osteoarthritis. Throughout a randomized, parallel and controlled clinical trial, fifty-six patients with medial knee osteoarthritis were randomly allocated to an intervention (n=28) or control group (n=28), and assessed at baseline and after three and six months. The intervention involved wearing Moleca(®) footwear for at least 6h/day, 7 days/week, over 6 months. The pain subscale of the Western Ontario and McMaster Universities Osteoarthritis Index was the primary outcome. The secondary outcomes were the other subscales, Lequesne score, distance walked in 6 min, knee oedema and effusion, knee adduction moment and paracetamol intake. Intention-to-treat analysis was performed using two-way casewise ANOVA (coefficient. Intervention group showed improvement in pain (effect size: 1.41, p<.001), function (effect size: 1.22, p=.001), stiffness (effect size: 0.76, p=.001), Lequesne score (effect size: 1.07, p<.001), and reduction by 21.8% in the knee adduction moment impulse (p=.017) during gait wearing Moleca(®). The analgesic intake was lower in the intervention group. The long-term use of Moleca(®) footwear relieves pain, improves self-reported function, reduces the knee loading while wearing Moleca(®), refrains the increase of analgesic intake in elderly women with knee osteoarthritis and can be considered as a conservative mechanical treatment option. ClinicalTrials.gov (NCT01342458). Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Changes in knee joint load indices from before to 12 months after arthroscopic partial meniscectomy

    DEFF Research Database (Denmark)

    Thorlund, Jonas Bloch; Holsgaard-Larsen, Anders; Creaby, M W

    2016-01-01

    with the contra-lateral leg. METHODS: We estimated indices of knee joint loading (external peak knee adduction moment (KAM), KAM impulse and peak knee flexion moment (KFM)) normalized to body size (i.e., body mass (BM) and height (HT)) using 3D gait analysis in 23 patients (17 men, mean (SD) 46.2 (6.4) years, BMI...... 25.8 (3.4) kg/m(2)) without radiographic knee OA before and 12 months after medial APM. Static alignment was assessed by radiography and self-reported outcomes by Knee injury and Osteoarthritis Outcome Score (KOOS). RESULTS: Peak KAM and KAM impulse increased in the APM leg compared to the contra......-lateral leg from before to 12 months after surgery (change difference: 0.38 Nm/BM*HT% 95% CI 0.01 to 0.76 (P = 0.049) and 0.20 Nm*s/BM*HT% 95% CI 0.10 to 0.30 (P

  7. Gait Mechanics in Those With/Without Medial Compartment Knee Osteoarthritis 5 Years After Anterior Cruciate Ligament Reconstruction

    Science.gov (United States)

    Khandha, Ashutosh; Manal, Kurt; Wellsandt, Elizabeth; Capin, Jacob; Snyder-Mackler, Lynn; Buchanan, Thomas S.

    2016-01-01

    The objective of the study was to evaluate differences in gait mechanics 5 years after unilateral anterior cruciate ligament reconstruction surgery, for non-osteoarthritic (n = 24) versus osteoarthritic (n = 9) subjects. For the involved knee, the osteoarthritic group demonstrated significantly lower peak knee flexion angles (non-osteoarthritic = 24.3 ± 4.6°, osteoarthritic = 19.1 ± 2.9°, p = 0.01) and peak knee flexion moments (non-osteoarthritic = 5.3 ± 1.2% Body Weight × Height, osteoarthritic = 4.4 ± 1.2% Body Weight × Height, p = 0.05). Differences in peak knee adduction moment approached significance, with a higher magnitude for the osteoarthritic group (non-osteoarthritic = 2.4 ±0.8% Body Weight × Height, osteoarthritic = 2.9 ± 0.5% Body Weight × Height, p = 0.09). Peak medial compartment joint load was evaluated using electromyography-informed neuromusculoskeletal modeling. Peak medial compartment joint load in the involved knee for the two groups was not different (non-osteoarthritic = 2.4 ± 0.4 Body Weight, osteoarthritic = 2.3 ± 0.6 Body Weight). The results suggest that subjects with dissimilar peak knee moments can have similar peak medial compartment joint load magnitudes. There was no evidence of inter-limb asymmetry for either group. Given the presence of inter-group differences (non-osteoarthritic vs. osteoarthritic) for the involved knee, but an absence of inter-limb asymmetry in either group, it may be necessary to evaluate how symmetry is achieved, over time, and to differentiate between good versus bad inter-limb symmetry, when evaluating knee gait parameters. PMID:27082166

  8. Walking velocity and step length adjustments affect knee joint contact forces in healthy weight and obese adults.

    Science.gov (United States)

    Milner, Clare E; Meardon, Stacey A; Hawkins, Jillian L; Willson, John D

    2018-04-28

    Knee osteoarthritis is a major public health problem and adults with obesity are particularly at risk. One approach to alleviating this problem is to reduce the mechanical load at the joint during daily activity. Adjusting temporospatial parameters of walking could mitigate cumulative knee joint mechanical loads. The purpose of this study was to determine how adjustments to velocity and step length affects knee joint loading in healthy weight adults and adults with obesity. We collected three-dimensional gait analysis data on 10 adults with a normal body mass index and 10 adults with obesity during over ground walking in nine different conditions. In addition to preferred velocity and step length, we also conducted combinations of 15% increased and decreased velocity and step length. Peak tibiofemoral joint impulse and knee adduction angular impulse were reduced in the decreased step length conditions in both healthy weight adults (main effect) and those with obesity (interaction effect). Peak knee joint adduction moment was also reduced with decreased step length, and with decreased velocity in both groups. We conclude from these results that adopting shorter step lengths during daily activity and when walking for exercise can reduce mechanical stimuli associated with articular cartilage degenerative processes in adults with and without obesity. Thus, walking with reduced step length may benefit adults at risk for disability due to knee osteoarthritis. Adopting a shorter step length during daily walking activity may reduce knee joint loading and thus benefit those at risk for knee cartilage degeneration. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 9999:XX-XX, 2018. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  9. Effects of physiotherapy treatment on knee osteoarthritis gait data using principal component analysis.

    Science.gov (United States)

    Gaudreault, Nathaly; Mezghani, Neila; Turcot, Katia; Hagemeister, Nicola; Boivin, Karine; de Guise, Jacques A

    2011-03-01

    Interpreting gait data is challenging due to intersubject variability observed in the gait pattern of both normal and pathological populations. The objective of this study was to investigate the impact of using principal component analysis for grouping knee osteoarthritis (OA) patients' gait data in more homogeneous groups when studying the effect of a physiotherapy treatment. Three-dimensional (3D) knee kinematic and kinetic data were recorded during the gait of 29 participants diagnosed with knee OA before and after they received 12 weeks of physiotherapy treatment. Principal component analysis was applied to extract groups of knee flexion/extension, adduction/abduction and internal/external rotation angle and moment data. The treatment's effect on parameters of interest was assessed using paired t-tests performed before and after grouping the knee kinematic data. Increased quadriceps and hamstring strength was observed following treatment (Pphysiotherapy on gait mechanics of knee osteoarthritis patients may be masked or underestimated if kinematic data are not separated into more homogeneous groups when performing pre- and post-treatment comparisons. Copyright © 2010 Elsevier Ltd. All rights reserved.

  10. DNA adducts as molecular dosimeters

    International Nuclear Information System (INIS)

    Lucier, G.W.

    1990-01-01

    There is compelling evidence that DNA adducts play an important role in the actions of many pulmonary carcinogens. During the last ten years sensitive methods (antibodies and 32 P-postlabeling) have been developed that permit detection of DNA adducts in tissues of animals or humans exposed to low levels of some genotoxic carcinogens. This capability has led to approaches designed to more reliably estimate the shape of the dose-response curve in the low dose region for a few carcinogens. Moreover, dosimetry comparisions can, in some cases, be made between animals and humans which help in judging the adequacy of animal models for human risk assessments. There are several points that need to be considered in the evaluation of DNA adducts as a molecular dosimeter. For example, DNA adduct formation is only one of many events that are needed for tumor development and some potent carcinogens do not form DNA adducts; i.e., TCDD. Other issues that need to be considered are DNA adduct heterogeneity, DNA repair, relationship of DNA adducts to somatic mutation and cell specificity in DNA adduct formation and persistence. Molecular epidemiology studies often require quantitation of adducts in cells such as lymphocytes which may or may not be reliable surrogates for adduct concentrations in target issues. In summary, accurate quantitation of low levels of DNA adducts may provide data useful in species to species extrapolation of risk including the development of more meaningful human monitoring programs

  11. The effect of prosthetic foot push-off on mechanical loading associated with knee osteoarthritis in lower extremity amputees.

    Science.gov (United States)

    Morgenroth, David C; Segal, Ava D; Zelik, Karl E; Czerniecki, Joseph M; Klute, Glenn K; Adamczyk, Peter G; Orendurff, Michael S; Hahn, Michael E; Collins, Steven H; Kuo, Art D

    2011-10-01

    Lower extremity amputation not only limits mobility, but also increases the risk of knee osteoarthritis of the intact limb. Dynamic walking models of non-amputees suggest that pushing-off from the trailing limb can reduce collision forces on the leading limb. These collision forces may determine the peak knee external adduction moment (EAM), which has been linked to the development of knee OA in the general population. We therefore hypothesized that greater prosthetic push-off would lead to reduced loading and knee EAM of the intact limb in unilateral transtibial amputees. Seven unilateral transtibial amputees were studied during gait under three prosthetic foot conditions that were intended to vary push-off. Prosthetic foot-ankle push-off work, intact limb knee EAM and ground reaction impulses for both limbs during step-to-step transition were measured. Overall, trailing limb prosthetic push-off work was negatively correlated with leading intact limb 1st peak knee EAM (slope=-.72±.22; p=.011). Prosthetic push-off work and 1st peak intact knee EAM varied significantly with foot type. The prosthetic foot condition with the least push-off demonstrated the largest knee EAM, which was reduced by 26% with the prosthetic foot producing the most push-off. Trailing prosthetic limb push-off impulse was negatively correlated with leading intact limb loading impulse (slope=-.34±.14; p=.001), which may help explain how prosthetic limb push-off can affect intact limb loading. Prosthetic feet that perform more prosthetic push-off appear to be associated with a reduction in 1st peak intact knee EAM, and their use could potentially reduce the risk and burden of knee osteoarthritis in this population. Published by Elsevier B.V.

  12. High knee abduction moments are common risk factors for patellofemoral pain (PFP) and anterior cruciate ligament (ACL) injury in girls: is PFP itself a predictor for subsequent ACL injury?

    Science.gov (United States)

    Myer, Gregory D; Ford, Kevin R; Di Stasi, Stephanie L; Foss, Kim D Barber; Micheli, Lyle J; Hewett, Timothy E

    2015-01-01

    Identifying risk factors for knee pain and anterior cruciate ligament (ACL) injury can be an important step in the injury prevention cycle. We evaluated two unique prospective cohorts with similar populations and methodologies to compare the incidence rates and risk factors associated with patellofemoral pain (PFP) and ACL injury. The 'PFP cohort' consisted of 240 middle and high school female athletes. They were evaluated by a physician and underwent anthropometric assessment, strength testing and three-dimensional landing biomechanical analyses prior to their basketball season. 145 of these athletes met inclusion for surveillance of incident (new) PFP by certified athletic trainers during their competitive season. The 'ACL cohort' included 205 high school female volleyball, soccer and basketball athletes who underwent the same anthropometric, strength and biomechanical assessment prior to their competitive season and were subsequently followed up for incidence of ACL injury. A one-way analysis of variance was used to evaluate potential group (incident PFP vs ACL injured) differences in anthropometrics, strength and landing biomechanics. Knee abduction moment (KAM) cut-scores that provided the maximal sensitivity and specificity for prediction of PFP or ACL injury risk were also compared between the cohorts. KAM during landing above 15.4 Nm was associated with a 6.8% risk to develop PFP compared to a 2.9% risk if below the PFP risk threshold in our sample. Likewise, a KAM above 25.3 Nm was associated with a 6.8% risk for subsequent ACL injury compared to a 0.4% risk if below the established ACL risk threshold. The ACL-injured athletes initiated landing with a greater knee abduction angle and a reduced hamstrings-to-quadriceps strength ratio relative to the incident PFP group. Also, when comparing across cohorts, the athletes who suffered ACL injury also had lower hamstring/quadriceps ratio than the players in the PFP sample (p15 Nm of knee abduction load

  13. Posterior Tibial Slope Angle Correlates With Peak Sagittal and Frontal Plane Knee Joint Loading During Robotic Simulations of Athletic Tasks

    Science.gov (United States)

    Bates, Nathaniel A.; Nesbitt, Rebecca J.; Shearn, Jason T.; Myer, Gregory D.; Hewett, Timothy E.

    2017-01-01

    tibial slope would lead to greater magnitude knee joint moments, specifically, internally generated knee adduction and flexion torques. Clinical Relevance The knee torques that positively correlated with increased tibial slope angle in this investigation are associated with heightened risk of ACL injury. Therefore, the present data indicated that a higher posterior tibial slope is correlated to increased knee loads that are associated with heightened risk of ACL injury. PMID:27159295

  14. Joint loading decreased by inexpensive and minimalist footwear in elderly women with knee osteoarthritis during stair descent.

    Science.gov (United States)

    Sacco, I C N; Trombini-Souza, F; Butugan, M K; Pássaro, A C; Arnone, A C; Fuller, R

    2012-03-01

    Previous studies indicate that flexible footwear, which mimics the biomechanics of walking barefoot, results in decreased knee loads in patients with knee osteoarthritis (OA) during walking. However, the effect of flexible footwear on other activities of daily living, such as descending stairs, remains unclear. Our objective was to evaluate the influence of inexpensive and minimalist footwear (Moleca) on knee adduction moment (KAM) during stair descent of elderly women with and without knee OA. Thirty-four elderly women were equally divided into an OA group and a control group (CG). Stair descent was evaluated in barefoot condition, while wearing the Moleca, and while wearing heeled shoes. Kinematics and ground reaction forces were measured to calculate KAM by using inverse dynamics. The OA group experienced a higher KAM during midstance under the barefoot condition (233.3%; P = 0.028), the Moleca (379.2%; P = 0.004), and heeled shoes (217.6%; P = 0.007). The OA group had a similar knee load during early, mid, and late stance with the Moleca compared with the barefoot condition. Heeled shoes increased the knee loads during the early-stance (versus barefoot [16.7%; P stair descent. The loads are similar to the barefoot condition and effectively decreased when compared with heeled shoes. Copyright © 2012 by the American College of Rheumatology.

  15. Nuclear moments

    CERN Document Server

    Kopferman, H; Massey, H S W

    1958-01-01

    Nuclear Moments focuses on the processes, methodologies, reactions, and transformations of molecules and atoms, including magnetic resonance and nuclear moments. The book first offers information on nuclear moments in free atoms and molecules, including theoretical foundations of hyperfine structure, isotope shift, spectra of diatomic molecules, and vector model of molecules. The manuscript then takes a look at nuclear moments in liquids and crystals. Discussions focus on nuclear paramagnetic and magnetic resonance and nuclear quadrupole resonance. The text discusses nuclear moments and nucl

  16. Alcohol, Aldehydes, Adducts and Airways

    Directory of Open Access Journals (Sweden)

    Muna Sapkota

    2015-11-01

    Full Text Available Drinking alcohol and smoking cigarettes results in the formation of reactive aldehydes in the lung, which are capable of forming adducts with several proteins and DNA. Acetaldehyde and malondialdehyde are the major aldehydes generated in high levels in the lung of subjects with alcohol use disorder who smoke cigarettes. In addition to the above aldehydes, several other aldehydes like 4-hydroxynonenal, formaldehyde and acrolein are also detected in the lung due to exposure to toxic gases, vapors and chemicals. These aldehydes react with nucleophilic targets in cells such as DNA, lipids and proteins to form both stable and unstable adducts. This adduction may disturb cellular functions as well as damage proteins, nucleic acids and lipids. Among several adducts formed in the lung, malondialdehyde DNA (MDA-DNA adduct and hybrid malondialdehyde-acetaldehyde (MAA protein adducts have been shown to initiate several pathological conditions in the lung. MDA-DNA adducts are pre-mutagenic in mammalian cells and induce frame shift and base-pair substitution mutations, whereas MAA protein adducts have been shown to induce inflammation and inhibit wound healing. This review provides an insight into different reactive aldehyde adducts and their role in the pathogenesis of lung disease.

  17. Reduced knee joint loading with lateral and medial wedge insoles for management of knee osteoarthritis: a protocol for a randomized controlled trial.

    Science.gov (United States)

    Lewinson, Ryan T; Collins, Kelsey H; Vallerand, Isabelle A; Wiley, J Preston; Woodhouse, Linda J; Reimer, Raylene A; Worobets, Jay T; Herzog, Walter; Stefanyshyn, Darren J

    2014-12-03

    Knee osteoarthritis (OA) progression has been linked to increased peak external knee adduction moments (KAMs). Although some trials have attempted to reduce pain and improve function in OA by reducing KAMs with a wedged footwear insole intervention, KAM reduction has not been specifically controlled for in trial designs, potentially explaining the mixed results seen in the literature. Therefore, the primary purpose of this trial is to identify the effects of reduced KAMs on knee OA pain and function. Forty-six patients with radiographically confirmed diagnosis medial knee OA will be recruited for this 3 month randomized controlled trial. Recruitment will be from Alberta and surrounding areas. Eligibility criteria include being between the ages of 40 and 85 years, have knee OA primarily localized to the medial tibiofemoral compartment, based on the American College of Rheumatology diagnostic criteria and be classified as having a Kellgren-Lawrence grade of 1 to 3. Patients will visit the laboratory at baseline for testing that includes dual x-ray absorptiometry, biomechanical testing, and surveys (KOOS, PASE activity scale, UCLA activity scale, comfort visual analog scale). At baseline, patients will be randomized to either a wedged insole group to reduce KAMs, or a waitlist control group where no intervention is provided. The survey tests will be repeated at 3 months, and response to wedged insoles over 3 months will be evaluated. This study represents the first step in systematically evaluating the effects of reduced KAMs on knee OA management by using a patient-specific wedged insole prescription procedure rather than providing the same insole to all patients. The results of this trial will provide indications as to whether reduced KAMs are an effective strategy for knee OA management, and whether a personalized approach to footwear insole prescription is warranted. NCT02067208.

  18. Alterations in walking knee joint stiffness in individuals with knee osteoarthritis and self-reported knee instability.

    Science.gov (United States)

    Gustafson, Jonathan A; Gorman, Shannon; Fitzgerald, G Kelley; Farrokhi, Shawn

    2016-01-01

    Increased walking knee joint stiffness has been reported in patients with knee osteoarthritis (OA) as a compensatory strategy to improve knee joint stability. However, presence of episodic self-reported knee instability in a large subgroup of patients with knee OA may be a sign of inadequate walking knee joint stiffness. The objective of this work was to evaluate the differences in walking knee joint stiffness in patients with knee OA with and without self-reported instability and examine the relationship between walking knee joint stiffness with quadriceps strength, knee joint laxity, and varus knee malalignment. Overground biomechanical data at a self-selected gait velocity was collected for 35 individuals with knee OA without self-reported instability (stable group) and 17 individuals with knee OA and episodic self-reported instability (unstable group). Knee joint stiffness was calculated during the weight-acceptance phase of gait as the change in the external knee joint moment divided by the change in the knee flexion angle. The unstable group walked with lower knee joint stiffness (p=0.01), mainly due to smaller heel-contact knee flexion angles (pknee flexion excursions (pknee stable counterparts. No significant relationships were observed between walking knee joint stiffness and quadriceps strength, knee joint laxity or varus knee malalignment. Reduced walking knee joint stiffness appears to be associated with episodic knee instability and independent of quadriceps muscle weakness, knee joint laxity or varus malalignment. Further investigations of the temporal relationship between self-reported knee joint instability and walking knee joint stiffness are warranted. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Knee mechanics during planned and unplanned sidestepping: a systematic review and meta-analysis.

    Science.gov (United States)

    Brown, Scott R; Brughelli, Matt; Hume, Patria A

    2014-11-01

    Knee joint mechanics during sidestepping are associated with anterior cruciate ligament injury. Unplanned sidestepping more closely emulates game scenarios when compared with planned sidestepping by limiting decision time, increasing knee loading and challenging the integrity of soft-tissue structures in the knee. It is important to quantify the loads that may challenge the integrity of the knee during planned and unplanned sidestepping. Our objective was to review literature on knee mechanics during planned and unplanned phases of sidestepping. PubMed, CINAHL, MEDLINE (EBSCO), SPORTDiscus and Web of Science were searched using the terms knee mechanics OR knee kine*, AND plan*, unplan*, anticipat*, unanticipat*, side*, cut* or chang*. A systematic approach was used to evaluate 4,629 records. Records were excluded when not available in English, only available in abstract of conference proceedings, not involving a change-of-direction sidestep, not comparing planned and unplanned or maintaining a running velocity greater than 2 m s(−1). Included studies were evaluated independently by two authors using a custom-designed methodological quality assessment derived from the Physiotherapy Evidence Database (PEDro) scale and then confirmed by a third author. Only six studies met the inclusion criteria and were retained for meta-analysis. Magnitude-based inferences were used to assess the standardised effect of the differences between planned and unplanned sidestepping. Knee angles and knee moments were extracted and reported for flexion/extension, abduction/adduction and internal/external rotation for initial contact, weight acceptance, peak push-off and final push-off phases of sidestepping. For kinematic variables, unplanned sidestepping produced a wide range of small to large increases in knee extension angles, small and moderate increases in knee abduction angles and a small increase in internal rotation angle relative to planned sidestepping during the sidestepping

  20. Modification of Knee Flexion Angle Has Patient-Specific Effects on Anterior Cruciate Ligament Injury Risk Factors During Jump Landing.

    Science.gov (United States)

    Favre, Julien; Clancy, Caitlin; Dowling, Ariel V; Andriacchi, Thomas P

    2016-06-01

    The incidence of anterior cruciate ligament (ACL) injuries may be decreased through the use of intervention programs that focus on increasing the knee flexion angle during jump landing, which decreases strain on the ACL. To investigate whether intervention training designed to change the knee flexion angle during landing causes secondary changes in other known measures associated with the risk of ACL injuries and to examine the time points when these secondary measures change. Controlled laboratory study. A total of 39 healthy recreational athletes performed a volleyball block jump task in an instrumented gait laboratory. The participants first completed the jumps without any modification to their normal landing technique. They were then given oral instruction to land softly and to increase their knee flexion angle during landing. Lower body kinematics and kinetics were measured before and after the modification using an optoelectronic motion capture system. The knee flexion angle after the modification significantly increased from 11.2° to 15.2° at initial contact and from 67.8° to 100.7° at maximum flexion, and the time between initial contact and maximum flexion increased from 177.4 to 399.4 milliseconds. The flexion modification produced a substantial reduction in vertical ground-reaction force (243.1 to 187.8 %BW) with a concomitant reduction in the maximum flexion moment. Interestingly, the flexion modification only affected the abduction angle and abduction moment for the group of participants that landed in an initial adducted position before the modification and had no significant effect on the group that landed in an abducted position. Increasing the knee flexion angle during jump landing may be an effective intervention to improve knee biomechanical risk factors associated with an ACL injury. However, the fact that the flexion modification only influenced critical risk factors (the abduction angle and abduction moment) in participants who initially

  1. Knee Injuries

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Knee Injuries KidsHealth / For Teens / Knee Injuries What's in ... can do to protect them. What's in a Knee? The knee is a joint , actually the largest ...

  2. Knee Replacement

    Science.gov (United States)

    Knee replacement is surgery for people with severe knee damage. Knee replacement can relieve pain and allow you to ... Your doctor may recommend it if you have knee pain and medicine and other treatments are not ...

  3. DNA adducts in senescent cells

    International Nuclear Information System (INIS)

    Gaubatz, J.W.

    1987-01-01

    Perturbations in DNA repair and other metabolic processes during development and aging might affect the steady-state level of genomic damage. The persistence or accumulation of DNA lesions in postmitotic cells could have a significant impact on proper cellular function, interfering with gene regulation for example. To test the notion that DNA damage increases as a function of age in non-dividing cells, DNA was purified from heart tissue of C57BL/6Nia mice at different ages and analyzed by post labeling techniques to detect DNA adducts. In the present experiments, four-dimensional, thin-layer chromatography was used to isolate aromatic adducts that were labeled with carrier-free (γ- 32 P) ATP under DNA-P excess conditions. The complexity and frequency of aromatic adducts varied between DNA samples. Several adducts were present in all preparations and were clearly more abundant in nucleotide maps of mature and old heart DNA. However, a direct correlation with age was not observed. In contrast, experiments in which aromatic adducts were first isolated by phase-transfer to 1-butanol, then labeled with excess (γ- 32 P)ATP indicated that there was an age-related increase in these adducts. The results are consistent with their earlier studies that showed alkyl adducts increased during aging of mouse myocardium and suggest that a common repair pathway might be involved

  4. A systematic review and meta-analysis into the effect of lateral wedge arch support insoles for reducing knee joint load in patients with medial knee osteoarthritis

    Science.gov (United States)

    Xing, Fei; Lu, Bin; Kuang, Ming-jie; Wang, Ying; Zhao, Yun-long; Zhao, Jie; Sun, Lei; Wang, Yan; Ma, Jian-xiong; Ma, Xin-long

    2017-01-01

    Abstract Objective: The aim of this study was to evaluate the immediate effects of lateral wedge arch support insoles (LWAS) on reducing the knee joint load in patients with medial knee osteoarthritis (OA) compared with an appropriate control. Methods: Databases including Medline, EMBASE, Web of Science, Wiley Online Library, Cochrane library, and Google Scholar were searched with no limits on study date or language, from the earliest available date to October 31, 2016. The included studies had to have the aim of reducing knee load and have an appropriate control. The main measured values were the first and second peak external knee adduction moments (EKAM) and the knee adduction angular impulse (KAAI). The random-effects model was used for analyzing the eligible studies. Results: Nine studies met the inclusion criteria with a total of 356 participants of whom 337 received LWAS treatment. The risk of methodological bias scores (quality index) ranged from 21 to 27 of 32. Treatment with LWAS resulted in statistically significant reductions in the first peak EKAM (P = .005), the second peak EKAM (P = .01), and the KAAI (P = .03). However, among trials in which the control treatment was control shoes, the LWAS showed no associations on the first peak EKAM (P = .10) or the KAAI (P =  .06); among trials in which the control treatment was neutral insoles, the LWAS showed no associations on the second peak EKAM (P = .21) or the KAAI (P = .23). At the same time, the LWAS showed no statistically significant reduction on the first peak EKAM (P = .39) when compared with flat insoles. Conclusion: Although meta-analysis outcomes of all studies indicated statistically significant associations between LWAS and reductions of the first peak EKAM, second peak EKAM and KAAI in people with medial knee OA while walking, different results existed in subgroups using various control conditions for comparison. These findings do not support the use of LWAS

  5. [Laryngeal adduction reflex].

    Science.gov (United States)

    Ptok, M; Bonenberger, S; Miller, S; Kühn, D; Jungheim, M

    2014-07-01

    Laryngeal Adductor Reflex Background: A rapid closure of the vocal folds is necessary, whenever foreign materials or food particles penetrate into the larynx. Otherwise a passage of these particles into the trachea or the lower respiratory tract would be imminent. An aspiration could mechanically block the respiratory tract and cause severe dyspnoea or cause aspiration pneumonia. For this systematic review a selective literature research in PubMed and Scopus using the keywords "laryngeal adductor reflex" and "vocal fold closure" has been carried out. Apart from the oesophago-glottal and pharyngo-glottal closure reflexes, the laryngeal adductor reflex (LAR) has been investigated in particular. The LAR qualifies as a reflectory laryngeal adductor mechanism and involves early, presumably di- or oligosynaptic ipsilateral LAR1 as well as late polysynaptic ipsi- and contralateral LAR2 components. In clinical routine diagnostic settings of dysphagia, LAR is only assessed qualitatively and usually triggered by air pulses or tactile stimulation. Dysphagiologists often find that not only the laryngeal sensibility in general is impaired, but especially the protective laryngeal adduction mechanism, which results in a higher risk of aspiration. Thus, it appears mandatory to test the LAR not only qualitatively but also quantitatively. Unfortunately a valid and reliable method that can be employed in clinical practice has not yet been put forward. © Georg Thieme Verlag KG Stuttgart · New York.

  6. Gait changes in patients with knee osteoarthritis are replicated by experimental knee pain

    DEFF Research Database (Denmark)

    Henriksen, Marius; Graven-Nielsen, Thomas; Aaboe, Jens

    2010-01-01

    Medial knee osteoarthritis (OA) is characterized by pain and associated with abnormal knee moments during walking. The relationship between knee OA pain and gait changes remains to be clarified, and a better understanding of this link could advance the treatment and prevention of disease...

  7. Efficacy of a biomechanically-based yoga exercise program in knee osteoarthritis: A randomized controlled trial.

    Science.gov (United States)

    Kuntz, Alexander B; Chopp-Hurley, Jaclyn N; Brenneman, Elora C; Karampatos, Sarah; Wiebenga, Emily G; Adachi, Jonathan D; Noseworthy, Michael D; Maly, Monica R

    2018-01-01

    Certain exercises could overload the osteoarthritic knee. We developed an exercise program from yoga postures with a minimal knee adduction moment for knee osteoarthritis. The purpose was to compare the effectiveness of this biomechanically-based yoga exercise (YE), with traditional exercise (TE), and a no-exercise attention-equivalent control (NE) for improving pain, self-reported physical function and mobility performance in women with knee osteoarthritis. Single-blind, three-arm randomized controlled trial. Community in Southwestern Ontario, Canada. A convenience sample of 31 women with symptomatic knee osteoarthritis was recruited through rheumatology, orthopaedic and physiotherapy clinics, newspapers and word-of-mouth. Participants were stratified by disease severity and randomly allocated to one of three 12-week, supervised interventions. YE included biomechanically-based yoga exercises; TE included traditional leg strengthening on machines; and NE included meditation with no exercise. Participants were asked to attend three 1-hour group classes/sessions each week. Primary outcomes were pain, self-reported physical function and mobility performance. Secondary outcomes were knee strength, depression, and health-related quality of life. All were assessed by a blinded assessor at baseline and immediately following the intervention. The YE group demonstrated greater improvements in KOOS pain (mean difference of 22.9 [95% CI, 6.9 to 38.8; p = 0.003]), intermittent pain (mean difference of -19.6 [95% CI, -34.8 to -4.4; p = 0.009]) and self-reported physical function (mean difference of 17.2 [95% CI, 5.2 to 29.2; p = 0.003]) compared to NE. Improvements in these outcomes were similar between YE and TE. However, TE demonstrated a greater improvement in knee flexor strength compared to YE (mean difference of 0.1 [95% CI, 0.1 to 0.2]. Improvements from baseline to follow-up were present in quality of life score for YE and knee flexor strength for TE, while both also

  8. Knee arthroscopy

    Science.gov (United States)

    ... debridement; Meniscus repair; Lateral release; Knee surgery; Meniscus - arthroscopy; Collateral ligament - arthroscopy ... pain relief (anesthesia) may be used for knee arthroscopy surgery: Local anesthesia. Your knee may be numbed ...

  9. Effectiveness of a long-term use of a minimalist footwear versus habitual shoe on pain, function and mechanical loads in knee osteoarthritis: a randomized controlled trial.

    Science.gov (United States)

    Trombini-Souza, Francis; Fuller, Ricardo; Matias, Alessandra; Yokota, Mariane; Butugan, Marco; Goldenstein-Schainberg, Claudia; Sacco, Isabel C N

    2012-07-12

    Recent studies have shown an important reduction of joint overload during locomotion in elderly women with knee osteoarthritis (OA) after short-term use of minimalist shoes. Our aim is to investigate the chronic effect of inexpensive and minimalist footwear on the clinical and functional aspects of OA and gait biomechanics of elderly women with knee OA. Fifty-six elderly women with knee OA grade 2 or 3 (Kellgren and Lawrence) are randomized into blocks and allocated to either the intervention group, which will use flexible, non-heeled shoes- Moleca®-for six months for at least six hours daily, or the control group, which could not use these shoes. Neither group is undergoing physical therapy treatment throughout the intervention period. Moleca® is a women's double canvas, flexible, flat walking shoe without heels, with a 5-mm anti-slip rubber sole and a 3-mm internal wedge of ethylene vinyl acetate. Both groups will be followed for six months and will be assessed at baseline condition, after three months, and after six months (end of intervention). All the assessments will be performed by a physiotherapist that is blind to the group allocation. The primary outcome is the pain Western Ontario and McMaster Universities Osteoarthritis (WOMAC) score. The secondary outcomes are global WOMAC score; joint stiffness and disability WOMAC scores; knee pain with a visual analogue scale; walking distance in the six-minute walk test; Lequesne score; amount and frequency (number of days) of paracetamol (500 mg) intake over six months; knee adduction moment during gait; global medical assessment score; and global patient auto-assessment score. At baseline, all patients receive a diary to record the hours of daily use of the footwear intervention; every two weeks, the same physiotherapist makes phone calls to all patients in order to verify adherence to treatment. The statistical analysis will be based on intention-to-treat analysis, as well as general linear models of

  10. Effectiveness of a long-term use of a minimalist footwear versus habitual shoe on pain, function and mechanical loads in knee osteoarthritis: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Trombini-Souza Francis

    2012-07-01

    Full Text Available Abstract Background Recent studies have shown an important reduction of joint overload during locomotion in elderly women with knee osteoarthritis (OA after short-term use of minimalist shoes. Our aim is to investigate the chronic effect of inexpensive and minimalist footwear on the clinical and functional aspects of OA and gait biomechanics of elderly women with knee OA. Methods/Design Fifty-six elderly women with knee OA grade 2 or 3 (Kellgren and Lawrence are randomized into blocks and allocated to either the intervention group, which will use flexible, non-heeled shoes— Moleca®—for six months for at least six hours daily, or the control group, which could not use these shoes. Neither group is undergoing physical therapy treatment throughout the intervention period. Moleca® is a women’s double canvas, flexible, flat walking shoe without heels, with a 5-mm anti-slip rubber sole and a 3-mm internal wedge of ethylene vinyl acetate. Both groups will be followed for six months and will be assessed at baseline condition, after three months, and after six months (end of intervention. All the assessments will be performed by a physiotherapist that is blind to the group allocation. The primary outcome is the pain Western Ontario and McMaster Universities Osteoarthritis (WOMAC score. The secondary outcomes are global WOMAC score; joint stiffness and disability WOMAC scores; knee pain with a visual analogue scale; walking distance in the six-minute walk test; Lequesne score; amount and frequency (number of days of paracetamol (500 mg intake over six months; knee adduction moment during gait; global medical assessment score; and global patient auto-assessment score. At baseline, all patients receive a diary to record the hours of daily use of the footwear intervention; every two weeks, the same physiotherapist makes phone calls to all patients in order to verify adherence to treatment. The statistical analysis will be based on intention

  11. Effects of sex and obesity on gait biomechanics before and six months after total knee arthroplasty: A longitudinal cohort study.

    Science.gov (United States)

    Paterson, K L; Sosdian, L; Hinman, R S; Wrigley, T V; Kasza, J; Dowsey, M; Choong, P; Bennell, K L

    2018-03-01

    Gait biomechanics, sex, and obesity can contribute to suboptimal outcomes from primary total knee arthroplasty. The aims of this study were to i) determine if sex and/or obesity influence the amount of change in gait biomechanics from pre-surgery to six months post-surgery and; ii) assess if gait returns to normal in men and women. Three-dimensional gait analysis was performed on 43 patients undergoing primary total knee arthroplasty for knee osteoarthritis (pre- and six months post-operative) and 40 asymptomatic controls. Mixed linear regression models were fit to assess which factors influenced change in gait biomechanics within the arthroplasty cohort, and interaction terms were included to assess if biomechanics returned to normal following surgery. Male peak knee adduction moment (p biomechanics after arthroplasty. Men retained abnormal gait patterns after surgery, whilst women did not. Further research should determine the long-term implications of gait abnormalities seen in men after arthroplasty. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. KNEE-JOINT LOADING IN KNEE OSTEOARTHRITIS: INFLUENCE OF ABDOMINAL AND THIGH FAT

    Science.gov (United States)

    Messier, Stephen P.; Beavers, Daniel P.; Loeser, Richard F.; Carr, J. Jeffery; Khajanchi, Shubham; Legault, Claudine; Nicklas, Barbara J.; Hunter, David J.; DeVita, Paul

    2014-01-01

    Purpose Using three separate models that included total body mass, total lean and total fat mass, and abdominal and thigh fat as independent measures, we determined their association with knee-joint loads in older overweight and obese adults with knee osteoarthritis (OA). Methods Fat depots were quantified using computed tomography and total lean and fat mass determined with dual energy x-ray absorptiometry in 176 adults (age = 66.3 yr., BMI = 33.5 kg·m−2) with radiographic knee OA. Knee moments and joint bone-on-bone forces were calculated using gait analysis and musculoskeletal modeling. Results Higher total body mass was significantly associated (p ≤ 0.0001) with greater knee compressive and shear forces, compressive and shear impulses (p knee extensor moments (p = 0.003). Regression analysis with total lean and total fat mass as independent variables revealed significant positive associations of total fat mass with knee compressive (p = 0.0001), shear (p knee extension moment (p = 0.008). Gastrocnemius and quadriceps forces were positively associated with total fat mass. Total lean mass was associated with knee compressive force (p = 0.002). A regression model that included total thigh and total abdominal fat found both were significantly associated with knee compressive and shear forces (p ≤ 0.04). Thigh fat was associated with the knee abduction (p = 0.03) and knee extension moment (p = 0.02). Conclusions Thigh fat, consisting predominately of subcutaneous fat, had similar significant associations with knee joint forces as abdominal fat despite its much smaller volume and could be an important therapeutic target for people with knee OA. PMID:25133996

  13. Knee joint loading in knee osteoarthritis: influence of abdominal and thigh fat.

    Science.gov (United States)

    Messier, Stephen P; Beavers, Daniel P; Loeser, Richard F; Carr, J Jeffery; Khajanchi, Shubham; Legault, Claudine; Nicklas, Barbara J; Hunter, David J; Devita, Paul

    2014-09-01

    Using three separate models that included total body mass, total lean and total fat mass, and abdominal and thigh fat as independent measures, we determined their association with knee joint loads in older overweight and obese adults with knee osteoarthritis (OA). Fat depots were quantified using computed tomography, and total lean and fat mass were determined with dual energy x-ray absorptiometry in 176 adults (age, 66.3 yr; body mass index, 33.5 kg·m) with radiographic knee OA. Knee moments and joint bone-on-bone forces were calculated using gait analysis and musculoskeletal modeling. Higher total body mass was significantly associated (P ≤ 0.0001) with greater knee compressive and shear forces, compressive and shear impulses (P knee extensor moments (P = 0.003). Regression analysis with total lean and total fat mass as independent variables revealed significant positive associations of total fat mass with knee compressive (P = 0.0001), shear (P knee extension moment (P = 0.008). Gastrocnemius and quadriceps forces were positively associated with total fat mass. Total lean mass was associated with knee compressive force (P = 0.002). A regression model that included total thigh and total abdominal fat found that both were significantly associated with knee compressive and shear forces (P ≤ 0.04). Thigh fat was associated with knee abduction (P = 0.03) and knee extension moment (P = 0.02). Thigh fat, consisting predominately of subcutaneous fat, had similar significant associations with knee joint forces as abdominal fat despite its much smaller volume and could be an important therapeutic target for people with knee OA.

  14. DNA adducts-chemical addons

    Directory of Open Access Journals (Sweden)

    T R Rajalakshmi

    2015-01-01

    Full Text Available DNA adduct is a piece of DNA covalently bond to a chemical (safrole, benzopyrenediol epoxide, acetaldehyde. This process could be the start of a cancerous cell. When a chemical binds to DNA, it gets damaged resulting in abnormal replication. This could be the start of a mutation and without proper DNA repair, this can lead to cancer. It is this chemical that binds with the DNA is our prime area of concern. Instead of performing the whole body analysis for diagnosing cancer, this test could be carried out for early detection of cancer. When scanning tunneling microscope is used, the DNA results can be obtained earlier. DNA adducts in scientific experiments are used as biomarkers.

  15. The association between eccentric hip abduction strength and hip and knee angular movements in recreational male runners

    DEFF Research Database (Denmark)

    Brund, René B. Korsgaard; Rasmussen, Sten; Nielsen, Rasmus O.

    2018-01-01

    Weak hip abductors may be related with increased hip adduction and knee abduction angular movement, which may be risk factors of lower extremity injuries. As the role of eccentric hip abduction strength (EHAS) on hip adduction angular movement and knee abduction angular movement (KABD) remains...... and Codamotion active marker system. Using multiple linear regression models (n=186 legs), no relationships between EHAS and hip and knee kinematics were found. A possible reason for the lack of relationship between EHAS and hip and knee kinematics may be owing to differences in the running kinematics. Some...

  16. Runner's Knee

    Science.gov (United States)

    ... require a lot of knee bending, such as biking, jumping, or skiing. Runner's knee happens when the ... is out of alignment, activities like running or biking can wear down the cartilage of the kneecap ( ...

  17. Anterior knee pain

    Science.gov (United States)

    Patellofemoral syndrome; Chondromalacia patella; Runner's knee; Patellar tendinitis; Jumper's knee ... kneecap (patella) sits over the front of your knee joint. As you bend or straighten your knee, ...

  18. Valgus-varus motion of the knee in normal level walking and stair climbing.

    Science.gov (United States)

    Yu, B; Stuart, M J; Kienbacher, T; Growney, E S; An, K-N

    1997-07-01

    OBJECTIVE: The knee valgus-varus moment and the knee angles were compared between normal level walking and stair climbing. DESIGN: Ten healthy subjects were tested for ascent, descent, and level walking. BACKGROUND: An understanding of the normal valgus-varus motion of the knee during stair climbing is needed to apply biomechanical analysis of stair climbing as a evaluation tool for knee osteoarthritis patients. METHODS: A motion analysis system, three force plates, and a flight of stairs were used to collect kinematic and kinetic data. The knee angles and moments were calculated from the collected kinematic and kinetic data. RESULTS: The knee varus angle for the maximum knee valgus moments in stair climbing was significantly greater than that in level walking. The knee valgus moment was significantly correlated to ground reaction forces and knee valgus-varus angle during stair climbing and level walking. CONCLUSIONS: There is a coupling between the knee valgus-varus motion and flexion-extension motion. Ground reaction forces are the major contributors to the within-subject variation in the knee valgus-varus moment during stair climbing and level walking. The knee valgus-varus angle is a major contributor to the between-subject variation in the knee valgus moment during stair climbing and level walking.

  19. DYNAMIC HIP ADDUCTION, ABDUCTION AND ABDOMINAL EXERCISES FROM THE HOLMICH GROIN-INJURY PREVENTION PROGRAM ARE INTENSE ENOUGH TO BE CONSIDERED STRENGTHENING EXERCISES - A CROSS-SECTIONAL STUDY

    DEFF Research Database (Denmark)

    Krommes, Kasper; Bandholm, Thomas; Jakobsen, Markus D

    2017-01-01

    and external obliques during isometric adduction against a football placed between the ankles (IBA), isometric adduction against a football placed between the knees (IBK), folding knife (FK), cross-country skiing on one leg (CCS), adduction partner (ADP) and abduction partner (ABP). The EMG-signals were...... normalized (nEMG) to an isometric maximal voluntary contraction for each tested muscle. RESULTS: Adductor longus activity during IBA was 84% nEMG (95% CI: 70-98) and during IBK it was 118% nEMG (95% CI 106-130). For the dynamic exercises, ADP evoked 87% nEMG (95% CI 69-105) in adductor longus, ABP evoked 88...

  20. Relationships between the center of pressure and the movements of the ankle and knee joints during the stance phase in patients with severe medial knee osteoarthritis.

    Science.gov (United States)

    Fukaya, Takashi; Mutsuzaki, Hirotaka; Okubo, Tomoyuki; Mori, Koichi; Wadano, Yasuyoshi

    2016-08-01

    The knee joint movement during the stance phase is affected by altered ankle movement and the center of pressure (COP). However the relationships between changes in the center of pressure (COP) and the altered kinematics and kinetics of the ankle and knee joints in patients with osteoarthritis (OA) of the knee are not well understood. The purpose of this study was to determine the relationships between changes in the COP and the altered kinematic and kinetic variables in ankle and knee joints during the stance phase in patients with medial knee OA. Fourteen patients with knee OA (21 knees) and healthy subjects were assessed by gait analysis using an eight-camera motion analysis system to record forward and lateral shifts in the COP and the angle and net internal moments of the knee and ankle joint. Spearman rank-correlation coefficients were used to determine the relationship between these results. In knees with medial OA, lateral shifts in the COP were correlated with knee flexion angle. Lateral shifts in the COP were correlated with the second peak of the knee extensor moment and correlated with the knee abductor moment. In patients with medial knee OA, lateral shifts in the COP were negatively correlated with the kinematic and kinetic variables in the sagittal plane of the knee joints. Controlling such lateral shifts in the COP may thus be an effective intervention for mechanical loads on the knee during the stance phase in patients with knee OA. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Formation of adduct of cerium (4) thenoyltrifluoroacetonate

    International Nuclear Information System (INIS)

    Anyfrieva, S.I.; Polyakova, G.V.; Snezhko, N.I.; Pechurova, N.I.; Martynenko, L.I.; Spitsyn, V.I.

    1981-01-01

    Adduct formation of thenoyltrifluoroacetonate of Ce(4) [Ce(TTFA) 4 ] with seven nitrogen- and oxygen-containing donor additional ligands is studied using the methods of IR-spectroscopy, derivatography, X-ray phase analysis. The presence of formation of Ce(TTFA) 4 adducts with phosphorus-containing additional ligands tributyl phosphate (TBP), trioctylphosphine oxide (TOPO), triphenylphosphine oxide (TPPO); α, α'-dipyridyl (Dipy) and o-phenanthroline (Phen) is established. The adduct Ce(TTFA) 4 stable to reduction is formed with Dipy, and in the case of Phen, TBP, TOPO, TPPO in the process of adduct formation the reduction of Ce(4) to Ce(3) takes place [ru

  2. Estimating the Mechanical Behavior of the Knee Joint during Crouch Gait: Implications for Real-Time Motor Control of Robotic Knee Orthoses

    Science.gov (United States)

    Damiano, Diane L.; Bulea, Thomas C.

    2016-01-01

    Individuals with cerebral palsy frequently exhibit crouch gait, a pathological walking pattern characterized by excessive knee flexion. Knowledge of the knee joint moment during crouch gait is necessary for the design and control of assistive devices used for treatment. Our goal was to 1) develop statistical models to estimate knee joint moment extrema and dynamic stiffness during crouch gait, and 2) use the models to estimate the instantaneous joint moment during weight-acceptance. We retrospectively computed knee moments from 10 children with crouch gait and used stepwise linear regression to develop statistical models describing the knee moment features. The models explained at least 90% of the response value variability: peak moment in early (99%) and late (90%) stance, and dynamic stiffness of weight-acceptance flexion (94%) and extension (98%). We estimated knee extensor moment profiles from the predicted dynamic stiffness and instantaneous knee angle. This approach captured the timing and shape of the computed moment (root-mean-squared error: 2.64 Nm); including the predicted early-stance peak moment as a correction factor improved model performance (root-mean-squared error: 1.37 Nm). Our strategy provides a practical, accurate method to estimate the knee moment during crouch gait, and could be used for real-time, adaptive control of robotic orthoses. PMID:27101612

  3. A controlled intervention study assessing the relation between hip abductor strength and knee valgus

    OpenAIRE

    Grytdal, Are

    2015-01-01

    Background: Anterior cruciate ligament (ACL) injury is a common and severe lower limb injury. Knee abduction moment has been associated with risk of non-contact ACL injury, and knee valgus angle has been reported as part of the non-contact ACL injury mechanism. Fatigued and weak hip abductors have been correlated with increased knee abduction moment and knee valgus angle. Strengthening the hip abductor muscles might play an important role in ACL injury prevention. Purpose: T...

  4. The relationship between patellofemoral and tibiofemoral morphology and gait biomechanics following arthroscopic partial medial meniscectomy

    DEFF Research Database (Denmark)

    Dempsey, Alasdair R.; Wang, Yuanyuan; Thorlund, Jonas Bloch

    2013-01-01

    adduction moment, knee adduction moment impulse, 1st peak in the knee flexion moment, knee extension range of motion, and the heel strike transient from the vertical ground reaction force trace were identified from the gait data. Results Increased knee stance phase range of motion was associated...

  5. Sidestep cutting technique and knee abduction loading: implications for ACL prevention exercises.

    Science.gov (United States)

    Kristianslund, Eirik; Faul, Oliver; Bahr, Roald; Myklebust, Grethe; Krosshaug, Tron

    2014-05-01

    Sidestep cutting technique is essential in programmes to prevent anterior cruciate ligament (ACL) injury. A better understanding of how technique affects potentially harmful joint loading may improve prevention programmes. The purpose of this study was to investigate the effect of sidestep cutting technique on maximum knee abduction moments. Cross-sectional study. Whole-body kinematics and knee joint kinetics were calculated in 123 female handball players (mean±SD, 22.5±7.0 years, 171±7 cm, 67±7 kg) performing sidestep cutting. Three cuts from each side were analysed. Linear regression was applied between selected technique factors and maximum knee abduction moment during the first 100 ms of the contact phase. Furthermore, we investigated to what degree the abduction moment originated from the magnitude of the ground reaction force (GRF) or the knee abduction moment arm of the GRF. Technique factors explained 62% of the variance in knee abduction moments. Cut width, knee valgus, toe landing, approach speed and cutting angle were the most significant predictors. An increase in one of these factors of 1 SD increased the knee abduction moment from 12% to 19%. The effect of the moment arm of the GRF was more important than the force magnitude for maximum knee abduction moments. Lower knee abduction loads during sidestep cutting may be achieved if cuts are performed as narrow cuts with low knee valgus and toe landings. These factors may be targeted in ACL injury prevention programmes.

  6. Partial knee replacement

    Science.gov (United States)

    ... good range of motion in your knee. The ligaments in your knee are stable. However, most people with knee arthritis have a surgery called a total knee arthroplasty (TKA). Knee replacement is most often done in people age 60 ...

  7. Jumper's Knee (Patellar Tendonitis)

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Jumper's Knee KidsHealth / For Teens / Jumper's Knee What's in this ... continued damage to the knee. How Does the Knee Work? To understand how jumper's knee happens, it ...

  8. Effects of the racket polar moment of inertia on dominant upper limb joint moments during tennis serve.

    Directory of Open Access Journals (Sweden)

    Isabelle Rogowski

    Full Text Available This study examined the effect of the polar moment of inertia of a tennis racket on upper limb loading in the serve. Eight amateur competition tennis players performed two sets of 10 serves using two rackets identical in mass, position of center of mass and moments of inertia other than the polar moment of inertia (0.00152 vs 0.00197 kg.m2. An eight-camera motion analysis system collected the 3D trajectories of 16 markers, located on the thorax, upper limbs and racket, from which shoulder, elbow and wrist net joint moments and powers were computed using inverse dynamics. During the cocking phase, increased racket polar moment of inertia was associated with significant increases in the peak shoulder extension and abduction moments, as well the peak elbow extension, valgus and supination moments. During the forward swing phase, peak wrist extension and radial deviation moments significantly increased with polar moment of inertia. During the follow-through phase, the peak shoulder adduction, elbow pronation and wrist external rotation moments displayed a significant inverse relationship with polar moment of inertia. During the forward swing, the magnitudes of negative joint power at the elbow and wrist were significantly larger when players served using the racket with a higher polar moment of inertia. Although a larger polar of inertia allows players to better tolerate off-center impacts, it also appears to place additional loads on the upper extremity when serving and may therefore increase injury risk in tennis players.

  9. Effects of the racket polar moment of inertia on dominant upper limb joint moments during tennis serve.

    Science.gov (United States)

    Rogowski, Isabelle; Creveaux, Thomas; Chèze, Laurence; Macé, Pierre; Dumas, Raphaël

    2014-01-01

    This study examined the effect of the polar moment of inertia of a tennis racket on upper limb loading in the serve. Eight amateur competition tennis players performed two sets of 10 serves using two rackets identical in mass, position of center of mass and moments of inertia other than the polar moment of inertia (0.00152 vs 0.00197 kg.m2). An eight-camera motion analysis system collected the 3D trajectories of 16 markers, located on the thorax, upper limbs and racket, from which shoulder, elbow and wrist net joint moments and powers were computed using inverse dynamics. During the cocking phase, increased racket polar moment of inertia was associated with significant increases in the peak shoulder extension and abduction moments, as well the peak elbow extension, valgus and supination moments. During the forward swing phase, peak wrist extension and radial deviation moments significantly increased with polar moment of inertia. During the follow-through phase, the peak shoulder adduction, elbow pronation and wrist external rotation moments displayed a significant inverse relationship with polar moment of inertia. During the forward swing, the magnitudes of negative joint power at the elbow and wrist were significantly larger when players served using the racket with a higher polar moment of inertia. Although a larger polar of inertia allows players to better tolerate off-center impacts, it also appears to place additional loads on the upper extremity when serving and may therefore increase injury risk in tennis players.

  10. No difference in gait between posterior cruciate retention and the posterior stabilized design after total knee arthroplasty

    NARCIS (Netherlands)

    van den Boom, Lennard G. H.; Halbertsma, Jan P. K.; van Raaij, Jos J. A. M.; Brouwer, Reinoud W.; Bulstra, Sjoerd K.; van den Akker-Scheek, Inge

    2014-01-01

    In the present study, knee joint kinematics (e.g. knee flexion/extension) and kinetics (e.g. knee flexion moments) are assessed after total knee arthroplasty (TKA) between patients implanted with either a unilateral posterior stabilized (PS) and a posterior cruciate-retaining (PCR) design. It was

  11. Imidazolidinone adducts of peptides and hemoglobin

    International Nuclear Information System (INIS)

    San George, R.C.; Hoberman, H.D.

    1986-01-01

    Acetaldehyde reacts selectively with the terminal amino groups of the α and β chains of hemoglobin to form stable adducts, the structures of which, based on 13 C NMR studies, are proposed to be diastereomeric 2-methyl imidazolidin-4-ones. In this scheme, acetaldelhyde forms a reversible Schiff base with the α-amino groups of the polypeptide chains which cyclize with the amide nitrogen of the first peptide bond to form the stable imidazolidinone adducts. In support of this mechanism, the authors found that in following the reaction of the peptide val-gly-gly with [1,2- 13 C] acetaldehyde, 13 C NMR resonances attributed to a Schiff base (δ = 170 ppm) were observed which slowly disappeared prior to appearance of resonances from a pair of stable adducts (δ = 70 and 71 ppm) believed to be the diastereomeric imidazolidinones. Schiff base formation appeared to limit the overall rate. Tetraglycine reacted in a similar manner but with a resonance from a single stable adduct observed representing the enantiomeric imidazolidinone adducts of this peptide. Peptides with proline in position 2 should be incapable of forming imidazolidinones, and the authors found that ala-pro-gly did in fact fail to form a stable adduct with acetaldehyde. The 2-methyl imidazolidin-4-one adducts of hemoglobin may be useful in determining the contribution of the amino terminal groups to the structure and functional properties of hemoglobins

  12. Hydrogen abstraction reactions by amide electron adducts

    International Nuclear Information System (INIS)

    Sevilla, M.D.; Sevilla, C.L.; Swarts, S.

    1982-01-01

    Electron reactions with a number of peptide model compounds (amides and N-acetylamino acids) in aqueous glasses at low temperature have been investigated using ESR spectroscopy. The radicals produced by electron attachment to amides, RC(OD)NDR', are found to act as hydrogen abstracting agents. For example, the propionamide electron adduct is found to abstract from its parent propionamide. Electron adducts of other amides investigated show similar behavior except for acetamide electron adduct which does not abstract from its parent compound, but does abstract from other amides. The tendency toward abstraction for amide electron adducts are compared to electron adducts of several carboxylic acids, ketones, aldehydes and esters. The comparison suggests the hydrogen abstraction tendency of the various deuterated electron adducts (DEAs) to be in the following order: aldehyde DEA > acid DEA = approximately ester DEA > ketone DEA > amide DEA. In basic glasses the hydrogen abstraction ability of the amide electron adducts is maintained until the concentration of base is increased sufficiently to convert the DEA to its anionic form, RC(O - )ND 2 . In this form the hydrogen abstracting ability of the radical is greatly diminished. Similar results were found for the ester and carboxylic acid DEA's tested. (author)

  13. Knee Replacement

    Science.gov (United States)

    ... days. Medications prescribed by your doctor should help control pain. During the hospital stay, you'll be encouraged to move your ... exercise your new knee. After you leave the hospital, you'll continue physical ... mobility and a better quality of life. And most knee replacements can be ...

  14. Soft tissue artifact compensation in knee kinematics by multi-body optimization: Performance of subject-specific knee joint models.

    Science.gov (United States)

    Clément, Julien; Dumas, Raphaël; Hagemeister, Nicola; de Guise, Jaques A

    2015-11-05

    Soft tissue artifact (STA) distort marker-based knee kinematics measures and make them difficult to use in clinical practice. None of the current methods designed to compensate for STA is suitable, but multi-body optimization (MBO) has demonstrated encouraging results and can be improved. The goal of this study was to develop and validate the performance of knee joint models, with anatomical and subject-specific kinematic constraints, used in MBO to reduce STA errors. Twenty subjects were recruited: 10 healthy and 10 osteoarthritis (OA) subjects. Subject-specific knee joint models were evaluated by comparing dynamic knee kinematics recorded by a motion capture system (KneeKG™) and optimized with MBO to quasi-static knee kinematics measured by a low-dose, upright, biplanar radiographic imaging system (EOS(®)). Errors due to STA ranged from 1.6° to 22.4° for knee rotations and from 0.8 mm to 14.9 mm for knee displacements in healthy and OA subjects. Subject-specific knee joint models were most effective in compensating for STA in terms of abduction-adduction, inter-external rotation and antero-posterior displacement. Root mean square errors with subject-specific knee joint models ranged from 2.2±1.2° to 6.0±3.9° for knee rotations and from 2.4±1.1 mm to 4.3±2.4 mm for knee displacements in healthy and OA subjects, respectively. Our study shows that MBO can be improved with subject-specific knee joint models, and that the quality of the motion capture calibration is critical. Future investigations should focus on more refined knee joint models to reproduce specific OA knee geometry and physiology. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Hip adduction and abduction strength profiles in elite soccer players

    DEFF Research Database (Denmark)

    Thorborg, Kristian; Serner, Andreas; Petersen, Jesper

    2011-01-01

    An ipsilateral hip adduction/abduction strength ratio of more than 90%, and hip adduction strength equal to that of the contralateral side have been suggested to clinically represent adequate strength recovery of hip adduction strength in athletes after groin injury. However, to what extent side-......-to-side symmetry in isometric hip adduction and abduction strength can be assumed in soccer players remains uncertain.......An ipsilateral hip adduction/abduction strength ratio of more than 90%, and hip adduction strength equal to that of the contralateral side have been suggested to clinically represent adequate strength recovery of hip adduction strength in athletes after groin injury. However, to what extent side...

  16. 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.

  17. Three-dimensional dynamic analysis of knee joint during gait in medial knee osteoarthritis using loading axis of knee.

    Science.gov (United States)

    Nishino, Katsutoshi; Omori, Go; Koga, Yoshio; Kobayashi, Koichi; Sakamoto, Makoto; Tanabe, Yuji; Tanaka, Masaei; Arakawa, Masaaki

    2015-07-01

    We recently developed a new method for three-dimensional evaluation of mechanical factors affecting knee joint in order to help identify factors that contribute to the progression of knee osteoarthritis (KOA). This study aimed to verify the clinical validity of our method by evaluating knee joint dynamics during gait. Subjects were 41 individuals (14 normal knees; 8 mild KOAs; 19 severe KOAs). The positions of skin markers attached to the body were captured during gait, and bi-planar X-ray images of the lower extremities were obtained in standing position. The positional relationship between the markers and femorotibial bones was determined from the X-ray images. Combining this relationship with gait capture allowed for the estimation of relative movement between femorotibial bones. We also calculated the point of intersection of loading axis of knee on the tibial proximal surface (LAK point) to analyze knee joint dynamics. Knee flexion range in subjects with severe KOA during gait was significantly smaller than that in those with normal knees (p=0.011), and knee adduction in those with severe KOA was significantly larger than in those with mild KOA (p<0.000). LAK point was locally loaded on the medial compartment of the tibial surface as KOA progressed, with LAK point of subjects with severe KOA rapidly shifting medially during loading response. Local loading and medial shear force were applied to the tibial surface during stance phase as medial KOA progressed. Our findings suggest that our method is useful for the quantitative evaluation of mechanical factors that affect KOA progression. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Knee pain

    Science.gov (United States)

    ... Fracture of the kneecap or other bones. Iliotibial band syndrome . Injury to the thick band that runs from your hip to the outside ... of your knee pain. When to Contact a Medical Professional Call your provider if: You cannot bear ...

  19. Effects of squats accompanied by hip joint adduction on the selective activity of the vastus medialis oblique.

    Science.gov (United States)

    Hyong, In Hyouk

    2015-06-01

    [Purpose] This study evaluated the effective selective activation method of the vastus medialis oblique for knee joint stabilization in patients with patellofemoral pain syndrome. [Subjects and Methods] Fifteen healthy college students (9 males, 6 females); mean age, height, and weight: 22.2 years, 167.8 cm, and 61.4 kg, respectively) participated. The knee angle was held at 60°. Muscle activities were measured once each during an ordinary squat and a squat accompanied by hip joint adduction. The muscle activities of the vastus medialis oblique and vastus lateralis were measured by electromyography for five seconds while maintaining 60° knee flexion. Electromyography signals were obtained at a sampling rate of 1,000 Hz and band pass filtering at 20-50 Hz. The obtained raw root mean square was divided by the maximal voluntary isometric contraction and expressed as a percentage. The selective activity of the vastus medialis oblique was assessed according to the muscle activity ratio of the vastus medialis oblique to the vastus lateralis. [Results] The activity ratio of the vastus medialis oblique was higher during a squat with hip joint adduction than without. [Conclusion] A squat accompanied by hip joint adduction is effective for the selective activation of the vastus medialis oblique.

  20. Knee Injuries and Disorders

    Science.gov (United States)

    Your knee joint is made up of bone, cartilage, ligaments and fluid. Muscles and tendons help the knee joint move. When any of these structures is hurt or diseased, you have knee problems. Knee problems can cause pain and difficulty ...

  1. Assembling Transgender Moments

    Science.gov (United States)

    Greteman, Adam J.

    2017-01-01

    In this article, the author seeks to assemble moments--scholarly, popular, and aesthetic--in order to explore the possibilities that emerge as moments collect in education's encounters with the needs, struggles, and possibilities of transgender lives and practices. Assembling moments, the author argues, illustrates the value of "moments"…

  2. Influence of Total Knee Arthroplasty on Gait Mechanics of the Replaced and Non-Replaced Limb During Stair Negotiation.

    Science.gov (United States)

    Standifird, Tyler W; Saxton, Arnold M; Coe, Dawn P; Cates, Harold E; Reinbolt, Jeffrey A; Zhang, Songning

    2016-01-01

    This study compared biomechanics during stair ascent in replaced and non-replaced limbs of total knee arthroplasty (TKA) patients with control limbs of healthy participants. Thirteen TKA patients and fifteen controls performed stair ascent. Replaced and non-replaced knees of TKA patients were less flexed at contact compared to controls. The loading response peak knee extension moment was greater in control and non-replaced knees compared with replaced. The push-off peak knee abduction moment was elevated in replaced limbs compared to controls. Loading and push-off peak hip abduction moments were greater in replaced limbs compared to controls. The push-off peak hip abduction moment was greater in non-replaced limbs compared to controls. Future rehabilitation protocols should consider the replaced knee and also the non-replaced knee and surrounding joints. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Association of baseline knee sagittal dynamic joint stiffness during gait and 2-year patellofemoral cartilage damage worsening in knee osteoarthritis.

    Science.gov (United States)

    Chang, A H; Chmiel, J S; Almagor, O; Guermazi, A; Prasad, P V; Moisio, K C; Belisle, L; Zhang, Y; Hayes, K; Sharma, L

    2017-02-01

    Knee sagittal dynamic joint stiffness (DJS) describes the biomechanical interaction between change in external knee flexion moment and flexion angular excursion during gait. In theory, greater DJS may particularly stress the patellofemoral (PF) compartment and thereby contribute to PF osteoarthritis (OA) worsening. We hypothesized that greater baseline knee sagittal DJS is associated with PF cartilage damage worsening 2 years later. Participants all had OA in at least one knee. Knee kinematics and kinetics during gait were recorded using motion capture systems and force plates. Knee sagittal DJS was computed as the slope of the linear regression line for knee flexion moments vs angles during the loading response phase. Knee magnetic resonance imaging (MRI) scans were obtained at baseline and 2 years later. We assessed the association between baseline DJS and baseline-to-2-year PF cartilage damage worsening using logistic regression with generalized estimating equations (GEE). Our sample had 391 knees (204 persons): mean age 64.2 years (SD 10.0); body mass index (BMI) 28.4 kg/m 2 (5.7); 76.5% women. Baseline knee sagittal DJS was associated with baseline-to-2-year cartilage damage worsening in the lateral (OR = 5.35, 95% CI: 2.37-12.05) and any PF (OR = 2.99, 95% CI: 1.27-7.04) compartment. Individual components of baseline DJS (i.e., change in knee moment or angle) were not associated with subsequent PF disease worsening. Capturing the concomitant effect of knee kinetics and kinematics during gait, knee sagittal DJS is a potentially modifiable risk factor for PF disease worsening. Copyright © 2016 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  4. Relationship between selected measures of strength and hip and knee excursion during unilateral and bilateral landings in women.

    Science.gov (United States)

    McCurdy, Kevin; Walker, John; Armstrong, Rusty; Langford, George

    2014-09-01

    The purpose of this study was to compare the relationship between several measures of single-joint, isometric, eccentric, and squat strength and unilateral and bilateral landing mechanics at the hip and knee in women. Twenty six healthy female subjects with previous athletic experience (height, 165.1 ± 7.01 cm; mass, 60.91 ± 7.14 kg; age, 20.9 ± 1.62 years) participated in this study. Hip and knee mechanics were measured using the MotionMonitor capture system (Innovative Sports Training, Inc.) with 3-dimensional electromagnetic sensors during bilateral (60 cm) and unilateral drop jumps (30 cm). On a separate day, isometric hip extension, external rotation, and abduction strength (lbs) were measured using a handheld dynamometer (Hoggan Health Industries, Inc.). Eccentric and isometric knee strength were measured on the Biodex IV Isokinetic Dynamometer (Biodex Medical Systems, Inc.). Free weight was used to measure the bilateral squat and a modified single-leg squat. The strongest correlations were found between squat strength and knee valgus (-0.77 ≤ r ≤ -0.83) and hip adduction (-0.5 ≤ r ≤ -0.65). After controlling for squat strength, hip external rotation strength and unilateral knee valgus (-0.41), hip abduction strength and bilateral knee valgus (-0.43), and knee flexion strength and bilateral hip adduction (-0.57) remained significant. Eccentric knee flexion strength and unilateral knee internal rotation was the only significant correlation for eccentric strength (-0.40). Squat strength seems to be the best predictor of knee valgus and was consistently related to hip adduction. Isometric and eccentric measures demonstrated few significant correlations with hip and knee excursion while demonstrating a low-to-moderate relationship. Hip and knee flexion and rotation do not seem to be related to strength. Squat strength should receive consideration during risk assessment for noncontact knee injury.

  5. Repair of furocoumarin adducts in mammalian cells

    International Nuclear Information System (INIS)

    Zolan, M.E.; Smith, C.A.; Hanawalt, P.C.

    1984-01-01

    DNA repair was studied in cultured mammalian cells treated with the furocoumarins 8-methoxypsoralen (8-MOP), aminomethyl trioxsalen, or angelicin and irradiated with near UV light. The amount of DNA cross-linked by 8-MOP in normal human cells decreased by about one-half in 24 hours after treatment; no decrease was observed in xeroderma pigmentosum cells, group A. At present, it is not known to what extent this decrease represents complete repair events at the sites of cross-links. Furocoumarin adducts elicited excision repair in normal human and monkey cells but not in xeroderma pigmentosum group A cells. This excision repair resembled in several aspects that elicited by pyrimidine dimers, formed in DNA by irradiation with 254-nm UV light; however, it appeared that for at least 8-MOP and aminomethyl trioxsalen, removal of adducts was not as efficient as was the removal of pyrimidine dimers. A comparison was also made of repair in the 172-base-pair repetitive alpha-DNA component of monkey cells to repair in the bulk of the genome. Although repair elicited by pyrimidine dimers in alpha-DNA was the same as in the bulk DNA, that following treatment of cells with either aminomethyl trioxsalen or angelicin and near UV was markedly deficient in alpha-DNA. This deficiency reflected the removal of fewer adducts from alpha-DNA after the same initial adduct frequencies. These results could mean that each furocoumarin may produce several structurally distinct adducts to DNA in cells and that the capacity of cellular repair systems to remove these various adducts may vary greatly

  6. Hip adduction and abduction strength profiles in elite soccer players

    DEFF Research Database (Denmark)

    Thorborg, Kristian; Serner, Andreas; Petersen, Jesper

    2011-01-01

    An ipsilateral hip adduction/abduction strength ratio of more than 90%, and hip adduction strength equal to that of the contralateral side have been suggested to clinically represent adequate strength recovery of hip adduction strength in athletes after groin injury. However, to what extent side-......-to-side symmetry in isometric hip adduction and abduction strength can be assumed in soccer players remains uncertain....

  7. DNA Adducts aand Human Atherosclerotis Lesions

    Czech Academy of Sciences Publication Activity Database

    Strejc, Přemysl; Boubelík, O.; Stávková, Zdena; Chvátalová, Irena; Šrám, Radim

    2001-01-01

    Roč. 42, - (2001), s. 662 ISSN 0008-5472. [Annual Meeting of Proceedings /92./. 24.03.2001-28.03.2001, New Orleans] R&D Projects: GA MZd NM10 Keywords : DNA adducts * LDL cholesterol Subject RIV: DN - Health Impact of the Environment Quality

  8. NITRO MUSK ADDUCTS OF RAINBOW TROUT ...

    Science.gov (United States)

    Rainbow trout and other fish species can serve as 'sentinel' species for the assessment of ecological status and the presence of certain environmental contaminants. As such they act as bioindicators of exposure. Here we present seminal data regarding dose-response and toxicokinetics of trout hemoglobin adduct formation from exposure to nitro musks that are frequently used as fragrance ingredients in formulations of personal care products. Hemoglobin adducts serve as biomarkers of exposure of the sentinel species as we have shown in previous studies of hemoglobin adducts formed in trout and environmental carp exposed to musk xylene (MX) and musk ketone (MK). Gas chromatography-electron capture negative ion chemical ionization-mass spectrometry (GC-NICI-MS) employing selected ion monitoring is used to measure 4-amino-MX (4-AMX), 2-amino-MX (2-AMX), and 2-amino-MK (2-AMK) released by alkaline hydrolysis from the sulfinamide adducts of hemoglobin. Dose-response and toxicokinetics were investigated using this sensitive method for analysis of these metabolites. In the dose-response investigation, the concentrations of 4-AMX and 2-2AMX are observed to pass through a maximum at 0.10 mg/g. In the case of 2-AMK, the adduct concentration is almost the same at dosages in the range of 0.030 to 0.10 mg/g. For toxicokinetics, the concentration of the metabolites in the Hb reaches a maximum in the 3-day sample after administration of MX or MK. Further elimination of the metabo

  9. Magnetic moments of baryons

    International Nuclear Information System (INIS)

    Lipkin, H.J.

    1983-06-01

    The new experimental values of hyperon magnetic moments are compared with sum rules predicted from general quark models. Three difficulties are encountered which are not easily explained by simple models. The isovector contributions of nonstrange quarks to hyperon moments are smaller than the corresponding contribution to nucleon moments, indicating either appreciable configuration mixing present in hyperon wave functions and absent in nucleons or an additional isovector contribution beyond that of valence quarks; e.g. from a pion cloud. The large magnitude of the ω - moment may indicate that the strange quark contribution to the ω moments is considerably larger than the value μ(#betta#) predicted by simple models which have otherwise been very successful. The set of controversial values from different experiments of the μ - moment include a value very close to -(1/2)μ(μ + ) which would indicate that strange quarks do not contribute at all to the μ moments. (author)

  10. 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...

  11. Quasi-stiffness of the knee joint in flexion and extension during the golf swing.

    Science.gov (United States)

    Choi, Ahnryul; Sim, Taeyong; Mun, Joung Hwan

    2015-01-01

    Biomechanical understanding of the knee joint during a golf swing is essential to improve performance and prevent injury. In this study, we quantified the flexion/extension angle and moment as the primary knee movement, and evaluated quasi-stiffness represented by moment-angle coupling in the knee joint. Eighteen skilled and 23 unskilled golfers participated in this study. Six infrared cameras and two force platforms were used to record a swing motion. The anatomical angle and moment were calculated from kinematic and kinetic models, and quasi-stiffness of the knee joint was determined as an instantaneous slope of moment-angle curves. The lead knee of the skilled group had decreased resistance duration compared with the unskilled group (P golf swing and developing rehabilitation strategies following surgery.

  12. Knee arthroscopy - discharge

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000199.htm Knee arthroscopy - discharge To use the sharing features on this ... surgery to treat problems in your knee (knee arthroscopy). You may have been checked for: Torn meniscus. ...

  13. Knee microfracture surgery

    Science.gov (United States)

    Cartilage regeneration - knee ... Three types of anesthesia may be used for knee arthroscopy surgery: Medicine to relax you, and shots of painkillers to numb the knee Spinal (regional) anesthesia General anesthesia (you will be ...

  14. Preventing Knee Injuries

    Science.gov (United States)

    ... Our Newsletter Donate Blog Skip breadcrumb navigation Preventing Knee Injuries Knee injuries in children and adolescent athletes ... this PDF Share this page: WHAT ARE COMMON KNEE INJURIES? Pain Syndromes One of the most common ...

  15. Lepton dipole moments

    CERN Document Server

    Marciano, William J

    2010-01-01

    This book provides a self-contained description of the measurements of the magnetic dipole moments of the electron and muon, along with a discussion of the measurements of the fine structure constant, and the theory associated with magnetic and electric dipole moments. Also included are the searches for a permanent electric dipole moment of the electron, muon, neutron and atomic nuclei. The related topic of the transition moment for lepton flavor violating processes, such as neutrinoless muon or tauon decays, and the search for such processes are included as well. The papers, written by many o

  16. Acetaldehyde Adducts in Alcoholic Liver Disease

    Directory of Open Access Journals (Sweden)

    Mashiko Setshedi

    2010-01-01

    Full Text Available Chronic alcohol abuse causes liver disease that progresses from simple steatosis through stages of steatohepatitis, fibrosis, cirrhosis, and eventually hepatic failure. In addition, chronic alcoholic liver disease (ALD, with or without cirrhosis, increases risk for hepatocellular carcinoma (HCC. Acetaldehyde, a major toxic metabolite, is one of the principal culprits mediating fibrogenic and mutagenic effects of alcohol in the liver. Mechanistically, acetaldehyde promotes adduct formation, leading to functional impairments of key proteins, including enzymes, as well as DNA damage, which promotes mutagenesis. Why certain individuals who heavily abuse alcohol, develop HCC (7.2–15% versus cirrhosis (15–20% is not known, but genetics and co-existing viral infection are considered pathogenic factors. Moreover, adverse effects of acetaldehyde on the cardiovascular and hematologic systems leading to ischemia, heart failure, and coagulation disorders, can exacerbate hepatic injury and increase risk for liver failure. Herein, we review the role of acetaldehyde adducts in the pathogenesis of chronic ALD and HCC.

  17. Adduct formation in Ce(IV) thenolytrifluoroacetonate

    International Nuclear Information System (INIS)

    Anufrieva, S.I.; Polyakova, G.V.; Snezhko, N.I.; Pechurova, N.I.; Martynenko, L.I.; Spitsyn, V.I.

    1982-01-01

    The literature contains no information on adduct formation in Ce(IV) β-diketonates with additional ligands. Since tetrakis-β-diketonates of Ce(IV) have four six-membered chelate rings, we can suppose that the introduction of an additional monodentate or bidentate ligand into the coordination sphere of Ce(IV) β-diketonates would lead to an increase in the coordination number (CN) of the Ce(IV) to nine or ten. The possibility of realization of such a high CN for Ce(IV) has not been proved; a study of adduct formation by Ce(IV) tetrakis-β-diketonates is thus of theoretical interest. Such an investigation might also be of practical interest, because the introduction of an additional ligand into the coordination sphere of a rare-earth β-diketonate usually increases the solubility of the β-diketonate in nonpolar solvents and increases the volatility of the compound; such a modification of the properties is important for various practical purposes. The aim of our work was to study the possibility of separating solid adducts of Ce(IV) tetrakis-thenoyltrifluoroacetonate with certain oxygen-containing and nitrogen-containing donor monodentate and bidentate ligands, and also to investigate their properties. As the β-diketone we used thenoyltrifluoroacetone (HTTFA), since in a parallel investigation it was found that Ce(TTFA) 4 has a high oxidation-reduction stability

  18. Influence of increasing knee flexion angle on knee-ankle varus stress during single-leg jump landing

    Directory of Open Access Journals (Sweden)

    Mariam A. Ameer, PhD

    2017-12-01

    Full Text Available Objectives: The primary aim of this study was to identify the relationship between the peak knee flexion angle and knee-ankle varus stress in the landing phase of the single-leg jump during running. Methods: Fifteen male handball players from the first Saudi Arabian handball team were incorporated in this study. Each player performed a single-leg jump-land after running a fixed distance of 450 cm. The data were measured using a 3D motion analysis system. The maximum knee flexion angle, knee varus angle, centre of pressure pathway in the medio-lateral direction, and ankle varus moment were measured. Results: The Pearson Product Moment Correlation showed that a greater knee flexion angle was related to a greater lateral displacement of the centre of pressure (r = 0.794, P = 0.000, a greater ankle varus moment (r = 0.707, P = 0.003, and a greater knee varus angle (r = 0.753, P = 0.001. In addition, the greater ankle varus moment was related to the greater lateral displacement of the centre of pressure (r = 0.734, P = 0.002. Conclusions: These findings may help physical therapists and conditioning professionals to understand the impact of increasing knee flexion angle on the lower limb joints. Such findings may help to develop training protocols for enhancing the lateral body reaction during the landing phase of the single-leg jump, which may protect the knee and ankle joints from excessive varus stresses. Keywords: 3D motion analysis, Ankle kinetic, Centre of pressure pathway, Handball playing, Knee kinematic, Single-leg jump

  19. Electric dipole moments reconsidered

    International Nuclear Information System (INIS)

    Rupertsberger, H.

    1989-01-01

    The electric dipole moments of elementary particles, atoms, molecules and their connection to the electric susceptibility are discussed for stationary states. Assuming rotational invariance it is emphasized that for such states only in the case of a parity and time reversal violating interaction the considered particles can obtain a nonvanishing expectation value for the electric dipole moment. 1 fig., 13 refs. (Author)

  20. Multi-moment maps

    DEFF Research Database (Denmark)

    Swann, Andrew Francis; Madsen, Thomas Bruun

    2012-01-01

    We introduce a notion of moment map adapted to actions of Lie groups that preserve a closed three-form. We show existence of our multi-moment maps in many circumstances, including mild topological assumptions on the underlying manifold. Such maps are also shown to exist for all groups whose second...

  1. Nuclear Anapole Moments

    Energy Technology Data Exchange (ETDEWEB)

    Michael Ramsey-Musolf; Wick Haxton; Ching-Pang Liu

    2002-03-29

    Nuclear anapole moments are parity-odd, time-reversal-even E1 moments of the electromagnetic current operator. Although the existence of this moment was recognized theoretically soon after the discovery of parity nonconservation (PNC), its experimental isolation was achieved only recently, when a new level of precision was reached in a measurement of the hyperfine dependence of atomic PNC in 133Cs. An important anapole moment bound in 205Tl also exists. In this paper, we present the details of the first calculation of these anapole moments in the framework commonly used in other studies of hadronic PNC, a meson exchange potential that includes long-range pion exchange and enough degrees of freedom to describe the five independent S-P amplitudes induced by short-range interactions. The resulting contributions of pi-, rho-, and omega-exchange to the single-nucleon anapole moment, to parity admixtures in the nuclear ground state, and to PNC exchange currents are evaluated, using configuration-mixed shell-model wave functions. The experimental anapole moment constraints on the PNC meson-nucleon coupling constants are derived and compared with those from other tests of the hadronic weak interaction. While the bounds obtained from the anapole moment results are consistent with the broad ''reasonable ranges'' defined by theory, they are not in good agreement with the constraints from the other experiments. We explore possible explanations for the discrepancy and comment on the potential importance of new experiments.

  2. Nuclear Anapole Moments

    International Nuclear Information System (INIS)

    Michael Ramsey-Musolf; Wick Haxton; Ching-Pang Liu

    2002-01-01

    Nuclear anapole moments are parity-odd, time-reversal-even E1 moments of the electromagnetic current operator. Although the existence of this moment was recognized theoretically soon after the discovery of parity nonconservation (PNC), its experimental isolation was achieved only recently, when a new level of precision was reached in a measurement of the hyperfine dependence of atomic PNC in 133Cs. An important anapole moment bound in 205Tl also exists. In this paper, we present the details of the first calculation of these anapole moments in the framework commonly used in other studies of hadronic PNC, a meson exchange potential that includes long-range pion exchange and enough degrees of freedom to describe the five independent S-P amplitudes induced by short-range interactions. The resulting contributions of pi-, rho-, and omega-exchange to the single-nucleon anapole moment, to parity admixtures in the nuclear ground state, and to PNC exchange currents are evaluated, using configuration-mixed shell-model wave functions. The experimental anapole moment constraints on the PNC meson-nucleon coupling constants are derived and compared with those from other tests of the hadronic weak interaction. While the bounds obtained from the anapole moment results are consistent with the broad ''reasonable ranges'' defined by theory, they are not in good agreement with the constraints from the other experiments. We explore possible explanations for the discrepancy and comment on the potential importance of new experiments

  3. The knee

    International Nuclear Information System (INIS)

    Rand, J.A.; Berquist, T.H.

    1985-01-01

    Evaluation of infection is difficult on the basis of radiographs. A clinical history suggestive of infection, such as excessive prolonged pain, drainage, fever, or a postoperative hematoma, is helpful in assessment. Radiographs may reveal periosteal new bone formation in long-standing cases of infection. Aspiration of the knee may or may not be helpful. Differential Tc-99m and gallium bone scans may be a useful adjunct in difficult cases. The gallium scan should show increased uptake relative to the Tc-99m scan to be considered positive. Bone scanning is not a useful criterion by itself for assessment of loosening

  4. Redshift or adduct stabilization -- a computational study of hydrogen bonding in adducts of protonated carboxylic acids

    DEFF Research Database (Denmark)

    Olesen, Solveig Gaarn; Hammerum, Steen

    2009-01-01

    It is generally expected that the hydrogen bond strength in a D-H-A adduct is predicted by the difference between the proton affinities of D and A, measured by the adduct stabilization, and demonstrated by the IR redshift of the D-H bond stretching vibrational frequency. These criteria do...... not always yield consistent predictions, as illustrated by the hydrogen bonds formed by the E and Z OH groups of protonated carboxylic acids. The delta-PA and the stabilization of a series of hydrogen bonded adducts indicate that the E OH group forms the stronger hydrogen bonds, whereas the bond length...... carboxylic acids are different. The OH bond length and IR redshift afford the better measure of hydrogen bond strength....

  5. The moment problem

    CERN Document Server

    Schmüdgen, Konrad

    2017-01-01

    This advanced textbook provides a comprehensive and unified account of the moment problem. It covers the classical one-dimensional theory and its multidimensional generalization, including modern methods and recent developments. In both the one-dimensional and multidimensional cases, the full and truncated moment problems are carefully treated separately. Fundamental concepts, results and methods are developed in detail and accompanied by numerous examples and exercises. Particular attention is given to powerful modern techniques such as real algebraic geometry and Hilbert space operators. A wide range of important aspects are covered, including the Nevanlinna parametrization for indeterminate moment problems, canonical and principal measures for truncated moment problems, the interplay between Positivstellensätze and moment problems on semi-algebraic sets, the fibre theorem, multidimensional determinacy theory, operator-theoretic approaches, and the existence theory and important special topics of multidime...

  6. Knee pain (image)

    Science.gov (United States)

    The location of knee pain can help identify the problem. Pain on the front of the knee can be due to bursitis, arthritis, or ... synovial fluid) that forms behind the knee. Overall knee pain can be due to bursitis, arthritis, tears in ...

  7. Synthesis and physicochemical investigation of adducts of rare earth thenoyltrifluoroacetonates

    International Nuclear Information System (INIS)

    Anufrieva, S.I.; Snezhko, N.I.; Martynenko, L.I.; Pechurova, N.I.

    1982-01-01

    Adducts of rare earth thenoyltrifluoroacetonates (3) have been synthesized with tributylphosphate (TBP), trioctylphosphenoxide (TOPO), triphenylphosphenoxide (TPO) of 1:1 and 1:2 composition as well as with α, α'-dipyridine (Dipy), o-phenanthroline (Phen) of 1:1 composition. The separated adducts have been studied by methods of element analysis, X-ray phase and derivatographic analyses and IR spectroscopy. It is shown that the adducts are more thermostable compared to the corresponding rare earth thenoyltrifluoroacetonate hydrates

  8. 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.

  9. Quadrupole moments of hadrons

    International Nuclear Information System (INIS)

    Krivoruchenko, M.I.

    1985-01-01

    In chiral bag model an expression is obtained for the quark wave functions with account of color and pion interaction of quarks. The quadrupole moments of nonstrange hadrons are calculated. Quadrupole moment of nucleon isobar is found to be Q(Δ)=-6.3x10 -28 esub(Δ)(cm)sup(2). Fredictions of the chiral bag model are in strong disagreement with the non-relativistic quark model

  10. Particle electric dipole moments

    CERN Document Server

    Pendlebury, J M

    2000-01-01

    Measurements of particle electric dipole moments (EDMs) continue to put powerful constraints on theories of T-symmetry and CP-symmetry violation, which form currently one of the most prominent fields in particle physics. EDM measurements have been concentrated on neutral systems such as the neutron and atoms and molecules. These measurements allow one to deduce, in turn, the electric dipole moments of the fundamental fermions, that is, the lighter leptons and quarks and also those of some heavy nuclei.

  11. Exercise Alters Gait Pattern but Not Knee Load in Patients with Knee Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Ssu-Yu Chang

    2016-01-01

    Full Text Available Six female patients with bilateral medial knee OA and 6 healthy controls were recruited. Patients with knee OA received a 6-week physiotherapist-supervised and home-based exercise program. Outcome measures, including the Western Ontario and McMaster Universities Arthritis Index and Short Form-36 Health Survey as well as objective biomechanical indices were obtained at baseline and follow-up. After treatment, no significant difference was observed in the knee abductor moment (KAM, lever arm, and ground reaction force. We, however, observed significantly improved pain and physical function as well as altered gait patterns, including a higher hip flexor moment and hip extension angle with a faster walking speed. Although KAM was unchanged, patients with bilateral knee OA showed an improved walking speed and altered the gait pattern after 6 weeks of supervised exercise. This finding suggests that the exercise intervention improves proximal joint mechanics during walking and can be considered for patients with bilateral knee OA. Non-weight-bearing strengthening without external resistance combined with stretching exercise may be an option to improve pain and function in individuals with OA who cannot perform high resistance exercises owing to pain or other reasons.

  12. Effects of counteracting external valgus moment on lateral tibial cartilage contact conditions and tibial rotation.

    Science.gov (United States)

    Shriram, Duraisamy; Parween, Rizuwana; Lee, Yee Han Dave; Subburaj, Karupppasamy

    2017-07-01

    Knee osteoarthritis that prevalently occurs at the medial compartment is a progressive chronic disorder affecting the articular cartilage of the knee joint, and lead to loss of joint functionality. Valgus braces have been used as a treatment procedure to unload the medial compartment for patients with medial osteoarthritis. Valgus braces through the application of counteracting external valgus moment shift the load from medial compartment towards the lateral compartment. Previous biomechanical studies focused only on the changes in varus moments before and after wearing the brace. The objective of this study was to investigate the influence of opposing external valgus moment applied by knee braces on the lateral tibial cartilage contact conditions using a 3D finite element model of the knee joint. Finite element simulations were performed on the knee joint model without and with the application of opposing valgus moment to mimic the unbraced and braced conditions. Lateral tibial cartilage contact pressures and contact area, and tibial rotation (varus-valgus and internal-external) were estimated for the complete walking gait cycle. The opposing valgus moment increased the maximum contact pressure and contact area on the lateral tibial cartilage compared to the normal gait moment. A peak contact pressure of 8.2 MPa and maximum cartilage loaded area of 28% (loaded cartilage nodes) on the lateral cartilage with the application of external valgus moment were induced at 50% of the gait cycle. The results show that the use of opposing valgus moment may significantly increase the maximum contact pressures and contact area on the lateral tibial cartilage and increases the risk of articular cartilage damage on the lateral compartment.

  13. Infrared spectra of volatile adduct of uranyl pivaloyltrifluoroacetonate with hexamethylphosphorotriamide

    International Nuclear Information System (INIS)

    Bukhmarina, V.N.; Dushin, R.B.; Sidorenko, G.V.; Suglobov, D.N.

    1983-01-01

    Adduct of uranyl pivaloyltrifluoroacetonate with hexamethylphosphortriamide (1), sublimated without decomposition and characterized by a high thermal stability, has been synthesized, as well as adducts of uranyl dipivaloylmethanate with hexamethylphosphortriamide (2) and dimethyl sulfoxide (3), sublimated with partial dissociation. IR spectra of crystalline adducts 1-3, their solutions in benzene; gaseous and matrix-isolated adduct 1 have been measured. It is shown that in gaseous phase 1 exists practically completely in non-dissociated form. It is detected that uranyl group in crystalline 1 and 2 and in matrix-isolated 1 in contrast to crystalline 3 and previously studied adducts of uranyl β-diketonates has an asymmetric structure. Strength constants of uranyl group in crystalline 1-3 and matrix-isolated 1 are determined

  14. Partial knee replacement - slideshow

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/presentations/100225.htm Partial knee replacement - series—Normal anatomy To use the sharing ... A.M. Editorial team. Related MedlinePlus Health Topics Knee Replacement A.D.A.M., Inc. is accredited ...

  15. Knee braces - unloading

    Science.gov (United States)

    ... most people talk about the arthritis in their knees, they are referring to a type of arthritis ... is caused by wear and tear inside your knee joints. Cartilage, the firm, rubbery tissue that cushions ...

  16. Loss of knee-extension strength is related to knee swelling after total knee arthroplasty

    DEFF Research Database (Denmark)

    Holm, Bente; Kristensen, Morten T; Bencke, Jesper

    2010-01-01

    To examine whether changes in knee-extension strength and functional performance are related to knee swelling after total knee arthroplasty (TKA).......To examine whether changes in knee-extension strength and functional performance are related to knee swelling after total knee arthroplasty (TKA)....

  17. Moment magnitude scale

    Energy Technology Data Exchange (ETDEWEB)

    Hanks, T.C.; Kanamori, H.

    1979-05-10

    The nearly conincident forms of the relations between seismic moment M/sub o/ and the magnitudes M/sub L/, M/sub s/, and M/sub w/ imply a moment magnitude scale M=2/3 log M/sub o/-10.7 which is uniformly valid for 3< or approx. =M/sub L/< or approx. = 7, 5 < or approx. =M/sub s/< or approx. =7 1/2 and M/sub w/> or approx. = 7 1/2.

  18. Magnetic moments of hyperons

    International Nuclear Information System (INIS)

    Overseth, O.E.

    1981-01-01

    The Fermilab Neutral Hyperon Beam Collaboration has measured the magnetic moments of Λ 0 , XI-neutral and XI-minus hyperons. With a recently published result for the Σ + hyperon, we now have precision measurements on the magnetic moments of six baryons. This allows a sensitive test of the quark model. The data are in qualitative agreement with the simple additive static quark model. Quantitatively however the data disagree with theoretical predictions by typically 15%. Several theoretical attempts to understand or remedy this discrepancy will be mentioned

  19. Risk analysis of occupational factors influencing the development of arthrosis of the knee

    International Nuclear Information System (INIS)

    Sahlstroem, Arne; Montgomery, Fredrik

    1997-01-01

    The aim of this study was to identify occupational activities important for the development of arthrosis of the knee, taking into account the confounding factors that were suspected or could be recognized. In the archives of the Department of Diagnostic Radiology at the Malmoe University Hospital all radiographs of weight-bearing knees of patients with painful knee joints from the period 1982-1986 were reassessed. We found 340 probands, i.e., subjects with arthrosis of the knee of at least grade 1 in the Ahlbaeck classification. These probands and their age- and sex-matched controls (680) were analyzed by a validated questionnaire for details of activities at work inducing knee moment over three 15-year-periods as well as their history of knee injuries at work or in their leisure time. The questionnaire was answered by 266 (79%) arthrosis probands and 463 controls (70%). The results of the questionnaire answers and of the recorded history of knee injuries were statistically analyzed by logistic regression. The relative risk of knee arthrosis was slightly increased (RR: 1.9; CI: 1.4-2.7) in probands with weight-bearing knee bending, i.e., dynamic load of the knee joint when bending, whereas knee injuries (meniscectomies and haemarthrosis) were associated with a higher risk. Weight-bearing knee bending corrected for confounders was not a significant factor for knee arthrosis. Overweight was observed to increase the relative risk. A sedentary profession had, on the other hand, a low risk. The knee injuries (66) were, but for 9 probands, sustained in leisure activities, mainly soccer. We thus conclude that work which induces weight-bearing knee bending by itself does not significantly increase the risk of developing arthrosis of the knee - knee injuries and overweight are more important

  20. Knee Joint Loads and Surrounding Muscle Forces during Stair Ascent in Patients with Total Knee Replacement.

    Directory of Open Access Journals (Sweden)

    Robert Rasnick

    Full Text Available Total knee replacement (TKR is commonly used to correct end-stage knee osteoarthritis. Unfortunately, difficulty with stair climbing often persists and prolongs the challenges of TKR patents. Complete understanding of loading at the knee is of great interest in order to aid patient populations, implant manufacturers, rehabilitation, and future healthcare research. Musculoskeletal modeling and simulation approximates joint loading and corresponding muscle forces during a movement. The purpose of this study was to determine if knee joint loadings following TKR are recovered to the level of healthy individuals, and determine the differences in muscle forces causing those loadings. Data from five healthy and five TKR patients were selected for musculoskeletal simulation. Variables of interest included knee joint reaction forces (JRF and the corresponding muscle forces. A paired samples t-test was used to detect differences between groups for each variable of interest (p<0.05. No differences were observed for peak joint compressive forces between groups. Some muscle force compensatory strategies appear to be present in both the loading and push-off phases. Evidence from knee extension moment and muscle forces during the loading response phase indicates the presence of deficits in TKR in quadriceps muscle force production during stair ascent. This result combined with greater flexor muscle forces resulted in similar compressive JRF during loading response between groups.

  1. In vivo six-degree-of-freedom knee-joint kinematics in overground and treadmill walking following total knee arthroplasty.

    Science.gov (United States)

    Guan, Shanyuanye; Gray, Hans A; Schache, Anthony G; Feller, Julian; de Steiger, Richard; Pandy, Marcus G

    2017-08-01

    No data are available to describe six-degree-of-freedom (6-DOF) knee-joint kinematics for one complete cycle of overground walking following total knee arthroplasty (TKA). The aims of this study were firstly, to measure 6-DOF knee-joint kinematics and condylar motion for overground walking following TKA; and secondly, to determine whether such data differed between overground and treadmill gait when participants walked at the same speed during both tasks. A unique mobile biplane X-ray imaging system enabled accurate measurement of 6-DOF TKA knee kinematics during overground walking by simultaneously tracking and imaging the joint. The largest rotations occurred for flexion-extension and internal-external rotation whereas the largest translations were associated with joint distraction and anterior-posterior drawer. Strong associations were found between flexion-extension and adduction-abduction (R 2  = 0.92), joint distraction (R 2  = 1.00), and anterior-posterior translation (R 2  = 0.77), providing evidence of kinematic coupling in the TKA knee. Although the measured kinematic profiles for overground walking were grossly similar to those for treadmill walking, several statistically significant differences were observed between the two conditions with respect to temporo-spatial parameters, 6-DOF knee-joint kinematics, and condylar contact locations and sliding. Thus, caution is advised when making recommendations regarding knee implant performance based on treadmill-measured knee-joint kinematic data. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1634-1643, 2017. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  2. Knee Arthrodesis After Failure of Knee Arthroplasty

    DEFF Research Database (Denmark)

    Gottfriedsen, Tinne B; Morville Schrøder, Henrik; Odgaard, Anders

    2016-01-01

    BACKGROUND: Arthrodesis is considered a salvage procedure after failure of a knee arthroplasty. Data on the use of this procedure are limited. The purpose of this study was to identify the incidence, causes, surgical techniques, and outcomes of arthrodesis after failed knee arthroplasty...... in a nationwide population. METHODS: Data were extracted from the Danish Civil Registration System, the Danish National Patient Register, and the Danish Knee Arthroplasty Register. A total of 92,785 primary knee arthroplasties performed in Denmark from 1997 to 2013 were identified by linking the data using....... Differences in cumulative incidence were compared with the Gray test. RESULTS: A total of 164 of the 165 arthrodeses were performed for causes related to failed knee arthroplasty. The 15-year cumulative incidence of arthrodesis was 0.26% (95% confidence interval, 0.21% to 0.31%). The 5-year cumulative...

  3. Moments of Negotiation

    NARCIS (Netherlands)

    Pieters, Jurgen

    2001-01-01

    'Moments of Negotiation' offers the first book-length and indepth analysis of the New Historicist reading method, which the American Shakespeare-scolar Stephen Greenblatt introduced at the beginning of the 1980s. Ever since, Greenblatt has been hailed as the prime representative of this movement,

  4. Magnetic moments revisited

    International Nuclear Information System (INIS)

    Towner, I.S.; Khanna, F.C.

    1984-01-01

    Consideration of core polarization, isobar currents and meson-exchange processes gives a satisfactory understanding of the ground-state magnetic moments in closed-shell-plus (or minus)-one nuclei, A = 3, 15, 17, 39 and 41. Ever since the earliest days of the nuclear shell model the understanding of magnetic moments of nuclear states of supposedly simple configurations, such as doubly closed LS shells +-1 nucleon, has been a challenge for theorists. The experimental moments, which in most cases are known with extraordinary precision, show a small yet significant departure from the single-particle Schmidt values. The departure, however, is difficult to evaluate precisely since, as will be seen, it results from a sensitive cancellation between several competing corrections each of which can be as large as the observed discrepancy. This, then, is the continuing fascination of magnetic moments. In this contribution, we revisit the subjet principally to identify the role played by isobar currents, which are of much concern at this conference. But in so doing we warn quite strongly of the dangers of considering just isobar currents in isolation; equal consideration must be given to competing processes which in this context are the mundane nuclear structure effects, such as core polarization, and the more popular meson-exchange currents

  5. The Humanist Moment

    Science.gov (United States)

    Higgins, Chris

    2014-01-01

    In "The Humanist Moment," Chris Higgins sets out to recover a tenable, living humanism, rejecting both the version vilified by the anti-humanists and the one sentimentalized by the reactionary nostalgists. Rescuing humanism from such polemics is only the first step, as we find at least nine rival, contemporary definitions of humanism.…

  6. Quantitation of DNA adducts by stable isotope dilution mass spectrometry

    Science.gov (United States)

    Tretyakova, Natalia; Goggin, Melissa; Janis, Gregory

    2012-01-01

    Exposure to endogenous and exogenous chemicals can lead to the formation of structurally modified DNA bases (DNA adducts). If not repaired, these nucleobase lesions can cause polymerase errors during DNA replication, leading to heritable mutations potentially contributing to the development of cancer. Due to their critical role in cancer initiation, DNA adducts represent mechanism-based biomarkers of carcinogen exposure, and their quantitation is particularly useful for cancer risk assessment. DNA adducts are also valuable in mechanistic studies linking tumorigenic effects of environmental and industrial carcinogens to specific electrophilic species generated from their metabolism. While multiple experimental methodologies have been developed for DNA adduct analysis in biological samples – including immunoassay, HPLC, and 32P-postlabeling – isotope dilution high performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) generally has superior selectivity, sensitivity, accuracy, and reproducibility. As typical DNA adducts concentrations in biological samples are between 0.01 – 10 adducts per 108 normal nucleotides, ultrasensitive HPLC-ESI-MS/MS methodologies are required for their analysis. Recent developments in analytical separations and biological mass spectrometry – especially nanoflow HPLC, nanospray ionization MS, chip-MS, and high resolution MS – have pushed the limits of analytical HPLC-ESI-MS/MS methodologies for DNA adducts, allowing researchers to accurately measure their concentrations in biological samples from patients treated with DNA alkylating drugs and in populations exposed to carcinogens from urban air, drinking water, cooked food, alcohol, and cigarette smoke. PMID:22827593

  7. Determination of adducts of polycyclic aromatic hydrocarbons to DNA

    International Nuclear Information System (INIS)

    Bean, R.M.; Chess, E.K.; Thomas, B.L.; Mann, D.B.; Dankovic, D.A.; Franz, J.A.; Springer, D.L.

    1987-01-01

    Adducts to deoxyribonucleic acid (DNA), formed from metabolites of polynuclear aromatic compounds, are relatively persistent and correlate with bioresponse (carcinogenicity). Therefore, qualitative and quantitative analysis of adducts in the DNA of individuals may provide valuable information as to recent exposure to carcinogenic hydrocarbons. Further, the ability to detect adducts in a large segment of a population may have significant epidemiological significance. The current thrust of the analytical development at PNL is to isolate the DNA, liberate the adducted hydrocarbon residue from the DNA with acid hydrolysis, and prepare derivatives of the hydrolyzed species that will enhance its detection, quantitation, and characterization using gas chromatography/mass spectrometry (GC/MS). They have initiated the development of the necessary techniques using benzo[a]pyrene (B[a]P). Samples of DNA adducts of radiolabeled B[a]P have been prepared for study by reacting DNA isolated from calf thymus with benzo[a]pyrene-7,8-diol-9,10-epoxide (the ultimate carcinogenic form of B[a]P). Other DNA/B[a]P samples have been prepared by painting the skin of mice with radiolabeled B[a]P. The ability to prepare research quantities of adducts using the hepatocyte preparation method reported by Dankovic et al is a significant development to their DNA adduct analysis program

  8. Possibilities and limitations of novel in-vitro knee simulator.

    Science.gov (United States)

    Verstraete, Matthias A; Victor, Jan

    2015-09-18

    The ex-vivo evaluation of knee kinematics remains vital to understand the impact of surgical treatments such as total knee arthroplasty (TKA). To that extent, knee simulators have been developed. However, these simulators have mainly focused on the simulation of a squatting motion. The relevance of this motion pattern for patients' activities of daily living is however questionable as squatting is difficult for elderly patients. Walking, stairs and cycling are more relevant motion patterns. This paper presents the design and control of a simulator that allows to independently control the applied kinematic and kinetic boundary conditions to simulate these daily life activities. Thereby, the knee is left with five degrees of freedom; only the knee flexion is actively controlled. From a kinetic point of view, the quadriceps and hamstring muscles are loaded. Optionally, a varus/valgus moment can be applied, facilitating a dynamic evaluation of the knee's stability. The simulator is based on three control loops, whose synchronization appears satisfactory. The input for these control loops can be determined from either musculoskeletal simulations or in accordance to literature data for traditional knee simulators. This opens the door towards an improved understanding of the knee biomechanics and comparison between different applied motion and force patterns. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Linking the generation of DNA adducts to lung cancer.

    Science.gov (United States)

    Ceppi, Marcello; Munnia, Armelle; Cellai, Filippo; Bruzzone, Marco; Peluso, Marco E M

    2017-09-01

    Worldwide, lung cancer is the leading cause of cancer death. DNA adducts are considered a reliable biomarker that reflects carcinogen exposure to tobacco smoke, but the central question is what is the relationship of DNA adducts and cancer? Therefore, we investigated this relationship by a meta-analysis of twenty-two studies with bronchial adducts for a total of 1091 subjects, 887 lung cancer cases and 204 apparently healthy individuals with no evidence of lung cancer. Our study shows that these adducts are significantly associated to increase lung cancer risk. The value of Mean Ratio lung-cancer (MR) of bronchial adducts resulting from the random effects model was 2.64, 95% C.I. 2.00-3.50, in overall lung cancer cases as compared to controls. The significant difference, with lung cancer patients having significant higher levels of bronchial adducts than controls, persisted after stratification for smoking habits. The MR lung-cancer value between lung cancer patients and controls for smokers was 2.03, 95% C.I. 1.42-2.91, for ex-smokers 3.27, 95% C.I. 1.49-7.18, and for non-smokers was 3.81, 95% C.I. 1.85-7.85. Next, we found that the generation of bronchial adducts is significantly related to inhalation exposure to tobacco smoke carcinogens confirming its association with volatile carcinogens. The MR smoking estimate of bronchial adducts resulting from meta-regression was 2.28, 95% Confidence Interval (C.I.) 1.10-4.73, in overall smokers in respect to non-smokers. The present work provides strengthening of the hypothesis that bronchial adducts are not simply relate to exposure, but are a cause of chemical-induced lung cancer. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. An extended OpenSim knee model for analysis of strains of connective tissues.

    Science.gov (United States)

    Marieswaran, M; Sikidar, Arnab; Goel, Anu; Joshi, Deepak; Kalyanasundaram, Dinesh

    2018-04-17

    OpenSim musculoskeletal models provide an accurate simulation environment that eases limitations of in vivo and in vitro studies. In this work, a biomechanical knee model was formulated with femoral articular cartilages and menisci along with 25 connective tissue bundles representing ligaments and capsules. The strain patterns of the connective tissues in the presence of femoral articular cartilage and menisci in the OpenSim knee model was probed in a first of its kind study. The effect of knee flexion (0°-120°), knee rotation (- 40° to 30°) and knee adduction (- 15° to 15°) on the anterior cruciate, posterior cruciate, medial collateral, lateral collateral ligaments and other connective tissues were studied by passive simulation. Further, a new parameter for assessment of strain namely, the differential inter-bundle strain of the connective tissues were analyzed to provide new insights for injury kinematics. ACL, PCL, LCL and PL was observed to follow a parabolic strain pattern during flexion while MCL represented linear strain patterns. All connective tissues showed non-symmetric parabolic strain variation during rotation. During adduction, the strain variation was linear for the knee bundles except for FL, PFL and TL. Strains higher than 0.1 were observed in most of the bundles during lateral rotation followed by abduction, medial rotation and adduction. In the case of flexion, highest strains were observed in aACL and aPCL. A combination of strains at a flexion of 0° with medial rotation of 30° or a flexion of 80° with rotation of 30° are evaluated as rupture-prone kinematics.

  11. Synthesis and physicochemical investigation of adducts of rare earth thenoyltrifluoroacetonates

    Energy Technology Data Exchange (ETDEWEB)

    Anufrieva, S.I.; Snezhko, N.I.; Martynenko, L.I.; Pechurova, N.I. (Moskovskij Gosudarstvennyj Univ. (USSR))

    1982-11-01

    Adducts of rare earth thenoyltrifluoroacetonates (3) have been synthesized with tributylphosphate (TBP), trioctylphosphenoxide (TOPO), triphenylphosphenoxide (TPO) of 1:1 and 1:2 composition as well as with ..cap alpha.., ..cap alpha..'-dipyridine (Dipy), o-phenanthroline (Phen) of 1:1 composition. The separated adducts have been studied by methods of element analysis, X-ray phase and derivatographic analyses and IR spectroscopy. It is shown that the adducts are more thermostable compared to the corresponding rare earth thenoyltrifluoroacetonate hydrates.

  12. DNA adduct measurements in zebra mussels, Dreissena polymorpha, Pallas

    International Nuclear Information System (INIS)

    Le Goff, J.; Gallois, J.; Pelhuet, L.; Devier, M.H.; Budzinski, H.; Pottier, D.; Andre, V.; Cachot, J.

    2006-01-01

    The purpose of this study was to examine PAH accumulation and bulky DNA adduct formation in the digestive gland of zebra mussels exposed in their habitat or in controlled laboratory conditions to complex mixture of PAH. DNA adducts were measured using a 32 P-postlabelling protocol with nuclease P1 enrichment adapted from Reddy and Randerath [Reddy, M.V., Randerath, K., 1986. Nuclease P1-mediated enhancement of sensitivity of 32 P-postlabelling test for structurally diverse DNA adducts. Carcinogenesis 7, 1543-1551]. Specimens collected in the upper part of the Seine estuary were shown to accumulate higher levels of PAH (up to 1.6 μg g -1 dry weight) in comparison to individuals from the reference site (0.053 μg g -1 dry weight). The former exhibited elevated levels of DNA adducts (up to 4.0/10 8 nucleotides) and higher diversity of individual adducts with five distinct spots being specifically detected in individuals originating from the Seine estuary. Zebra mussels exposed for 5 days to 0.01% (v/v) of organic extract of sediment from the Seine estuary were shown to accumulate high amounts of PAH (up to 138 μg g -1 dry weight) but exhibited relatively low levels of DNA adducts. Exposure to benzo[a]pyrene led to a dose-dependent accumulation of B[a]P (up to 7063 μg g -1 dry weight) and a clear induction of DNA adduct formation in the digestive gland of mussels (up to 1.13/10 8 nucleotides). Comparisons with other bivalves exposed to the same model PAH, revealed similar levels of adducts and comparable adduct profiles with a main adduct spot and a second faint one. This study clearly demonstrated that zebra mussels are able to biotransform B[a]P and probably other PAH into reactive metabolites with DNA-binding activity. This work also demonstrated the applicability of the nuclease P1 enhanced 32 P-postlabelling method for bulky adduct detection in the digestive gland of zebra mussels. DNA adduct measurement in zebra mussels could be a suitable biomarker to monitor

  13. DNA adduct measurements in zebra mussels, Dreissena polymorpha, Pallas

    Energy Technology Data Exchange (ETDEWEB)

    Le Goff, J. [GRECAN, UPRES EA-1772, University of Caen, Caen (France); Gallois, J. [Laboratory F. Duncombe, Conseil General du Calvados, Caen (France); Pelhuet, L. [LPTC, UMR-5472 CNRS, University Bordeaux I, Bordeaux (France); Devier, M.H. [LPTC, UMR-5472 CNRS, University Bordeaux I, Bordeaux (France); Budzinski, H. [LPTC, UMR-5472 CNRS, University Bordeaux I, Bordeaux (France); Pottier, D. [GRECAN, UPRES EA-1772, University of Caen, Caen (France); Andre, V. [GRECAN, UPRES EA-1772, University of Caen, Caen (France); Cachot, J. [LEMA, UPRES EA-3222, IFRMP 23, University of Le Havre, 25 rue Philippe Lebon, B.P. 540, 76058 Le Havre Cedex (France)]. E-mail: jerome.cachot@univ-lehavre.fr

    2006-08-12

    The purpose of this study was to examine PAH accumulation and bulky DNA adduct formation in the digestive gland of zebra mussels exposed in their habitat or in controlled laboratory conditions to complex mixture of PAH. DNA adducts were measured using a {sup 32}P-postlabelling protocol with nuclease P1 enrichment adapted from Reddy and Randerath [Reddy, M.V., Randerath, K., 1986. Nuclease P1-mediated enhancement of sensitivity of {sup 32}P-postlabelling test for structurally diverse DNA adducts. Carcinogenesis 7, 1543-1551]. Specimens collected in the upper part of the Seine estuary were shown to accumulate higher levels of PAH (up to 1.6 {mu}g g{sup -1} dry weight) in comparison to individuals from the reference site (0.053 {mu}g g{sup -1} dry weight). The former exhibited elevated levels of DNA adducts (up to 4.0/10{sup 8} nucleotides) and higher diversity of individual adducts with five distinct spots being specifically detected in individuals originating from the Seine estuary. Zebra mussels exposed for 5 days to 0.01% (v/v) of organic extract of sediment from the Seine estuary were shown to accumulate high amounts of PAH (up to 138 {mu}g g{sup -1} dry weight) but exhibited relatively low levels of DNA adducts. Exposure to benzo[a]pyrene led to a dose-dependent accumulation of B[a]P (up to 7063 {mu}g g{sup -1} dry weight) and a clear induction of DNA adduct formation in the digestive gland of mussels (up to 1.13/10{sup 8} nucleotides). Comparisons with other bivalves exposed to the same model PAH, revealed similar levels of adducts and comparable adduct profiles with a main adduct spot and a second faint one. This study clearly demonstrated that zebra mussels are able to biotransform B[a]P and probably other PAH into reactive metabolites with DNA-binding activity. This work also demonstrated the applicability of the nuclease P1 enhanced {sup 32}P-postlabelling method for bulky adduct detection in the digestive gland of zebra mussels. DNA adduct measurement in

  14. Biomechanical factors associated with the development of tibiofemoral knee osteoarthritis

    DEFF Research Database (Denmark)

    van Tunen, Joyce A C; Dell'Isola, Andrea; Juhl, Carsten

    2016-01-01

    INTRODUCTION: Altered biomechanics, increased joint loading and tissue damage, might be related in a vicious cycle within the development of knee osteoarthritis (KOA). We have defined biomechanical factors as joint-related factors that interact with the forces, moments and kinematics in and aroun...... publications in peer-reviewed journals and presentations at (inter)national conferences. TRIAL REGISTRATION NUMBER: CRD42015025092....

  15. Comments and corrections on 3D modeling studies of locomotor muscle moment arms in archosaurs

    Directory of Open Access Journals (Sweden)

    Karl Bates

    2015-10-01

    Full Text Available In a number of recent studies we used computer modeling to investigate the evolution of muscle leverage (moment arms and function in extant and extinct archosaur lineages (crocodilians, dinosaurs including birds and pterosaurs. These studies sought to quantify the level of disparity and convergence in muscle moment arms during the evolution of bipedal and quadrupedal posture in various independent archosaur lineages, and in doing so further our understanding of changes in anatomy, locomotion and ecology during the group’s >250 million year evolutionary history. Subsequent work by others has led us to re-evaluate our models, which revealed a methodological error that impacted on the results obtained from the abduction–adduction and long-axis rotation moment arms in our published studies. In this paper we present corrected abduction–adduction and long axis rotation moment arms for all our models, and evaluate the impact of this new data on the conclusions of our previous studies. We find that, in general, our newly corrected data differed only slightly from that previously published, with very few qualitative changes in muscle moments (e.g., muscles originally identified as abductors remained abductors. As a result the majority of our previous conclusions regarding the functional evolution of key muscles in these archosaur groups are upheld.

  16. Redefining the political moment

    Directory of Open Access Journals (Sweden)

    James Arvanitakis

    2011-07-01

    Full Text Available On 16 February 2003, more than half a million people gathered in Sydney, Australia, as part of a global anti-war protest aimed at stopping the impending invasion of Iraq by the then US Administration. It is difficult to estimate how many millions marched on the coordinated protest, but it was by far the largest mobilization of a generation. Walking and chanting on the streets of Sydney that day, it seemed that a political moment was upon us. In a culture that rarely embraces large scale activism, millions around Australian demanded to be heard. The message was clear: if you do not hear us, we would be willing to bring down a government. The invasion went ahead, however, with the then Australian government, under the leadership of John Howard, being one of the loudest and staunchest supporters of the Bush Administrations drive to war. Within 18 months, anti-war activists struggled to have a few hundred participants take part in anti-Iraq war rallies, and the Howard Government was comfortably re-elected for another term. The political moment had come and gone, with both social commentators and many members of the public looking for a reason. While the conservative media was often the focus of analysis, this paper argues that in a time of late capitalism, the political moment is hollowed out by ‘Politics’ itself. That is to say, that formal political processes (or ‘Politics’ undermine the political practices that people participate in everyday (or ‘politics’. Drawing on an ongoing research project focusing on democracy and young people, I discuss how the concept of ’politics‘ has been destabilised and subsequently, the political moment has been displaced. This displacement has led to a re-definition of ‘political action’ and, I argue, the emergence of a different type of everyday politics.

  17. Projective moment invariants

    Czech Academy of Sciences Publication Activity Database

    Suk, Tomáš; Flusser, Jan

    2004-01-01

    Roč. 26, č. 10 (2004), s. 1364-1367 ISSN 0162-8828 R&D Projects: GA ČR GA201/03/0675 Institutional research plan: CEZ:AV0Z1075907 Keywords : projective transform * moment invariants * object recognition Subject RIV: JD - Computer Applications, Robotics Impact factor: 4.352, year: 2004 http://library.utia.cas.cz/prace/20040112.pdf

  18. Joint Moment-Angle Properties of the Hip Extensors in Subjects With and Without Patellofemoral Pain.

    Science.gov (United States)

    Kindel, Curtis; Challis, John

    2018-04-01

    Strength deficits of hip extension in individuals with patellofemoral syndrome are commonly reported in literature. No literature to date has examined these deficits with variable positions of the knee and hip; altering knee angle alters the length and therefore potentially the force produced by the biarticular muscles. Beyond strength, neuromuscular control can also be assessed through the analysis of isometric joint moment steadiness. Subjects consisted of a group of individuals with patellofemoral syndrome (n = 9), and a group of age- and size-matched controls with no symptoms (n = 9). Maximum isometric joint moments for hip extension were measured at 4 points within the joint's range of motion, at 2 different knee positions (0° and 90°) for each group. The joint moment signals were analyzed by computing signal Coefficient of Variation (CV). The results indicate that no significant differences were found between the groups of subjects for the hip extension moments when the knee was extended. However, there was a significant difference between the groups for the joint moments of hip extension with the knee flexed at all 4 hip positions. Results also showed hip extension CV values to be significantly higher in the patellofemoral group compared with the control group, indicating greater signal noise and therefore poorer neuromuscular control of the hip extensor musculature. This study demonstrated that individuals with patellofemoral syndrome have reduced hip extension strength and reduced neuromuscular control with the knee flexed compared with a control group. These results have implications for the etiology of patellofemoral syndrome and its rehabilitation.

  19. Adducts of uranium tetrachloride with neutral Schiff bases

    Energy Technology Data Exchange (ETDEWEB)

    Doretti, L; Madalosso, F; Sitran, S; Faleschini, S; Vigato, P A [Consiglio Nazionale delle Ricerche, Padua (Italy). Lab. di Chimica e Tecnologia dei Radioelementi

    1977-01-01

    Studies are reported of adducts of UCl/sub 4/ with various Schiff base ligands: N-(phenyl)benzalaldimine, N-(propyl) salicylaldimine, N-(phenyl) salicylaldimine, N-(2-hydroxyphenyl)benzalaldimine, N-(4-chlorophenyl)salcylaldimine, N-(4-nitrophenyl)salicylaldimine, N,N'-o-phenylenebis(salycylideneimine). The synthesis and characterization of these ligands is reported, and the preparation and characterization of the relative adducts of UCl/sub 4/: their IR spectra are reported and discussed.

  20. Adducts of uranium tetrachloride with neutral Schiff bases

    International Nuclear Information System (INIS)

    Doretti, L.; Madalosso, F.; Sitran, S.; Faleschini, S.; Vigato, P.A.

    1977-01-01

    Studies are reported of adducts of UCl 4 with various Schiff base ligands: N-(phenyl)benzalaldimine, N-(propyl) salicylaldimine, N-(phenyl) salicylaldimine, N-(2-hydroxyphenyl)benzalaldimine, N-(4-chlorophenyl)salcylaldimine, N-(4-nitrophenyl)salicylaldimine, N,N'-o-phenylenebis (salycylideneimine). The synthesis and characterization of these ligands is reported, and the preparation and characterization of the relative adducts of UCl 4 : their IR spectra are reported and discussed. (author)

  1. Detection of Dichlorvos Adducts in a Hepatocyte Cell Line

    Science.gov (United States)

    2014-06-30

    5453543 aldo -keto reductase family 1 member C1 aldo -keto reductase TRUE 3 156523970 alpha-2-HS-glycoprotein preproprotein 5 4503571 alpha-enolase...enolase, (YISPDQLADLYK), three variants were identified with adducts on the first, second, or both tyrosines (Figure 2), and for one peptide in aldo -keto...suggesting the possibility that DDVP adducts could alter biological activities. The modifications of aldo -keto reductase family 1 members at three

  2. Detection of carcinogen-DNA adducts by radioimmunoassay

    International Nuclear Information System (INIS)

    Poirier, M.C.; Yuspa, S.H.; Weinstein, I.B.; Blobstein, S.

    1977-01-01

    Covalent binding of carcinogen to nucleic acids is believed to be an essential component of the carcinogenic process, so it is desirable to have highly sensitive and specific methods for detecting such adducts in cells and tissues exposed to known and suspected carcinogens. A radioimmunoassay is here described capable of detecting nanogram amounts of DNA adducts resulting from the covalent binding of the carcinogen N-2-acetylaminofluorene and its activated N-acetoxy derivative. (author)

  3. How to measure responses of the knee to lateral perturbations during gait? A proof-of-principle for quantification of knee instability.

    Science.gov (United States)

    van den Noort, Josien C; Sloot, Lizeth H; Bruijn, Sjoerd M; Harlaar, Jaap

    2017-08-16

    Knee instability is a major problem in patients with anterior cruciate ligament injury or knee osteoarthritis. A valid and clinically meaningful measure for functional knee instability is lacking. The concept of the gait sensitivity norm, the normalized perturbation response of a walking system to external perturbations, could be a sensible way to quantify knee instability. The aim of this study is to explore the feasibility of this concept for measurement of knee responses, using controlled external perturbations during walking in healthy subjects. Nine young healthy participants walked on a treadmill, while three dimensional kinematics were measured. Sudden lateral translations of the treadmill were applied at five different intensities during stance. Right knee kinematic responses and spatio-temporal parameters were tracked for the perturbed stride and following four cycles, to calculate perturbation response and gait sensitivity norm values (i.e. response/perturbation) in various ways. The perturbation response values in terms of knee flexion and abduction increased with perturbation intensity and decreased with an increased number of steps after perturbation. For flexion and ab/adduction during midswing, the gait sensitivity norm values were shown to be constant over perturbation intensities, demonstrating the potential of the gait sensitivity norm as a robust measure of knee responses to perturbations. These results show the feasibility of using the gait sensitivity norm concept for certain gait indicators based on kinematics of the knee, as a measure of responses during perturbed gait. The current findings in healthy subjects could serve as reference-data to quantify pathological knee instability. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Effects of Prophylactic Knee Bracing on Lower Limb Kinematics, Kinetics, and Energetics During Double-Leg Drop Landing at 2 Heights.

    Science.gov (United States)

    Ewing, Katie A; Begg, Rezaul K; Galea, Mary P; Lee, Peter V S

    2016-07-01

    Anterior cruciate ligament (ACL) injuries commonly occur during landing maneuvers. Prophylactic knee braces were introduced to reduce the risk of ACL injuries, but their effectiveness is debated. We hypothesized that bracing would improve biomechanical factors previously related to the risk of ACL injuries, such as increased hip and knee flexion angles at initial contact and at peak vertical ground-reaction force (GRF), increased ankle plantar flexion angles at initial contact, decreased peak GRFs, and decreased peak knee extension moment. We also hypothesized that bracing would increase the negative power and work of the hip joint and would decrease the negative power and work of the knee and ankle joints. Controlled laboratory study. Three-dimensional motion and force plate data were collected from 8 female and 7 male recreational athletes performing double-leg drop landings from 0.30 m and 0.60 m with and without a prophylactic knee brace. GRFs, joint angles, moments, power, and work were calculated for each athlete with and without a knee brace. Prophylactic knee bracing increased the hip flexion angle at peak GRF by 5.56° (P knee flexion angle at peak GRF by 4.75° (P = .001), and peak hip extension moment by 0.44 N·m/kg (P knee and ankle. No differences in peak GRFs and peak knee extension moment were observed with bracing. The application of a prophylactic knee brace resulted in improvements in important biomechanical factors associated with the risk of ACL injuries. Prophylactic knee braces may help reduce the risk of noncontact knee injuries in recreational and professional athletes while playing sports. Further studies should investigate different types of prophylactic knee braces in conjunction with existing training interventions so that the sports medicine community can better assess the effectiveness of prophylactic knee bracing. © 2016 The Author(s).

  5. Polycyclic aromatic hydrocarbons and PAH-related DNA adducts.

    Science.gov (United States)

    Ewa, Błaszczyk; Danuta, Mielżyńska-Švach

    2017-08-01

    Investigations on the impact of chemicals on the environment and human health have led to the development of an exposome concept. The exposome refers to the totality of exposures received by a person during life, including exposures to life-style factors, from the prenatal period to death. The exposure to genotoxic chemicals and their reactive metabolites can induce chemical modifications of DNA, such as, for example, DNA adducts, which have been extensively studied and which play a key role in chemically induced carcinogenesis. Development of different methods for the identification of DNA adducts has led to adopting DNA adductomic approaches. The ability to simultaneously detect multiple PAH-derived DNA adducts may allow for the improved assessment of exposure, and offer a mechanistic insight into the carcinogenic process following exposure to PAH mixtures. The major advantage of measuring chemical-specific DNA adducts is the assessment of a biologically effective dose. This review provides information about the occurrence of the polycyclic aromatic hydrocarbons (PAHs) and their influence on human exposure and biological effects, including PAH-derived DNA adduct formation and repair processes. Selected methods used for determination of DNA adducts have been presented.

  6. Knee effusion after total knee replacement.

    OpenAIRE

    Cameron, H. U.

    1993-01-01

    The various causes of effusions in artificial knees can be divided into four groups: implant related, technique related, interface problems, and infection. Diagnosis can be made from the patient's history and a clinical examination. Treatment is usually surgical revision.

  7. Traumatic knee extension deficit (the locked knee)

    DEFF Research Database (Denmark)

    Helmark, I C; Neergaard, K; Krogsgaard, M R

    2007-01-01

    In the present study we investigated the validity of magnetic resonance imaging (MRI) and arthroscopy in knees with acute, traumatic extension deficit (the "locked knee"), and evaluated whether arthroscopy of knees with no mechanical pathology could be avoided by MRI evaluation. The study consisted...... of 50 patients who had an acute, traumatic extension deficit of the knee. All patients were submitted to MRI prior to arthroscopy. Following MRI and surgery, standardized forms were filled out, attempting to objectify the findings. The orthopaedic surgeon was not aware of the MRI result prior to surgery....... Evaluating MRI, all grade-3 meniscal lesions were considered able to cause a mechanical block as well as acute partial or total anterior cruciate ligament (ACL)-ruptures. ACL-ruptures with an old appearance were not considered able to cause locking. Assuming that arthroscopy was the gold standard...

  8. Heavy quark and magnetic moment

    International Nuclear Information System (INIS)

    Mubarak, Ahmad; Jallu, M.S.

    1979-01-01

    The magnetic moments and transition moments of heavy hadrons including the conventional particles are obtained under the SU(5) truth symmetry scheme. To this end state vectors are defined and the quark additivity principle is taken into account. (author)

  9. Moment methods for nonlinear maps

    International Nuclear Information System (INIS)

    Pusch, G.D.; Atomic Energy of Canada Ltd., Chalk River, ON

    1993-01-01

    It is shown that Differential Algebra (DA) may be used to push moments of distributions through a map, at a computational cost per moment comparable to pushing a single particle. The algorithm is independent of order, and whether or not the map is symplectic. Starting from the known result that moment-vectors transform linearly - like a tensor - even under a nonlinear map, I suggest that the form of the moment transformation rule indicates that the moment-vectors are elements of the dual to DA-vector space. I propose several methods of manipulating moments and constructing invariants using DA. I close with speculations on how DA might be used to ''close the circle'' to solve the inverse moment problem, yielding an entirely DA-and-moment-based space-charge code. (Author)

  10. Knee Joint Loads and Surrounding Muscle Forces during Stair Ascent in Patients with Total Knee Replacement

    Science.gov (United States)

    Rasnick, Robert; Standifird, Tyler; Reinbolt, Jeffrey A.; Cates, Harold E.

    2016-01-01

    Total knee replacement (TKR) is commonly used to correct end-stage knee osteoarthritis. Unfortunately, difficulty with stair climbing often persists and prolongs the challenges of TKR patents. Complete understanding of loading at the knee is of great interest in order to aid patient populations, implant manufacturers, rehabilitation, and future healthcare research. Musculoskeletal modeling and simulation approximates joint loading and corresponding muscle forces during a movement. The purpose of this study was to determine if knee joint loadings following TKR are recovered to the level of healthy individuals, and determine the differences in muscle forces causing those loadings. Data from five healthy and five TKR patients were selected for musculoskeletal simulation. Variables of interest included knee joint reaction forces (JRF) and the corresponding muscle forces. A paired samples t-test was used to detect differences between groups for each variable of interest (pknee extension moment and muscle forces during the loading response phase indicates the presence of deficits in TKR in quadriceps muscle force production during stair ascent. This result combined with greater flexor muscle forces resulted in similar compressive JRF during loading response between groups. PMID:27258086

  11. Jumper's Knee (Patellar Tendonitis) (For Parents)

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Jumper's Knee (Patellar Tendonitis) KidsHealth / For Parents / Jumper's Knee (Patellar ... prevent continued damage to the knee. How the Knee Works To understand how jumper's knee happens, it ...

  12. Multi-joint postural behavior in patients with knee osteoarthritis.

    Science.gov (United States)

    Turcot, Katia; Sagawa, Yoshimasa; Hoffmeyer, Pierre; Suvà, Domizio; Armand, Stéphane

    2015-12-01

    Previous studies have demonstrated balance impairment in patients with knee osteoarthritis (OA). Although it is currently accepted that postural control depends on multi-joint coordination, no study has previously considered this postural strategy in patients suffering from knee OA. The objectives of this study were to investigate the multi-joint postural behavior in patients with knee OA and to evaluate the association with clinical outcomes. Eighty-seven patients with knee OA and twenty-five healthy elderly were recruited to the study. A motion analysis system and two force plates were used to investigate the joint kinematics (trunk and lower body segments), the lower body joint moments, the vertical ground reaction force ratio and the center of pressure (COP) during a quiet standing task. Pain, functional capacity and quality of life status were also recorded. Patients with symptomatic and severe knee OA adopt a more flexed posture at all joint levels in comparison with the control group. A significant difference in the mean ratio was found between groups, showing an asymmetric weight distribution in patients with knee OA. A significant decrease in the COP range in the anterior-posterior direction was also observed in the group of patients. Only small associations were observed between postural impairments and clinical outcomes. This study brings new insights regarding the postural behavior of patients with severe knee OA during a quiet standing task. The results confirm the multi-joint asymmetric posture adopted by this population. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. The pediatric knee.

    Science.gov (United States)

    Orth, Robert C

    2013-03-01

    Knee pain is a common problem in children and adolescents, and MRI of the knee is the most commonly performed pediatric cross-sectional musculoskeletal imaging exam. The purpose of this pictorial review is to highlight differences between adult and pediatric knee imaging with an emphasis on normal developmental variants, injury and disease patterns unique to children and adolescents, and differences in response and presentation to conditions affecting both adults and children.

  14. Imaging of knee arthroplasty

    International Nuclear Information System (INIS)

    Miller, Theodore T.

    2005-01-01

    Knee replacement surgery, either with unicompartmental or total systems, is common. The purpose of this manuscript is to review the appearance of normal knee arthroplasty and the appearances of complications such as infection, polyethylene wear, aseptic loosening and particle-induced osteolysis, patellofemoral abnormalities, axial instability, and periprosthetic and component fracture. Knowledge of the potential complications and their imaging appearances will help the radiologist in the diagnostic evaluation of the patient with a painful knee arthroplasty

  15. Imaging of knee arthroplasty

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Theodore T. [Department of Radiology, North Shore University Hospital, 825 Northern Blvd., Great Neck, NY 11021 (United States)]. E-mail: TMiller@NSHS.edu

    2005-05-01

    Knee replacement surgery, either with unicompartmental or total systems, is common. The purpose of this manuscript is to review the appearance of normal knee arthroplasty and the appearances of complications such as infection, polyethylene wear, aseptic loosening and particle-induced osteolysis, patellofemoral abnormalities, axial instability, and periprosthetic and component fracture. Knowledge of the potential complications and their imaging appearances will help the radiologist in the diagnostic evaluation of the patient with a painful knee arthroplasty.

  16. Gait analysis of patients with an off-the-shelf total knee replacement versus customized bi-compartmental knee replacement.

    Science.gov (United States)

    Wang, Henry; Foster, Jonathan; Franksen, Natasha; Estes, Jill; Rolston, Lindsey

    2018-04-01

    Newer TKR designs have been introduced to the market with the aim of overcoming common sizing problems with older TKR designs. Furthermore, since a sizable percentage of patients with OA present with disease limited to the medial/lateral knee compartment in addition to the patellofemoral joint, for whom, a customized bi-compartmental knee replacement (BKR) is available as a treatment option. To date, there is very little information regarding knee strength and mechanics during gait for patients implanted with these modern TKR and BKR designs. The purpose of the study was to evaluate knee strength and mechanics during walking for patients with either a modern off the shelf TKR or a customized BKR and compare these findings to a cohort of healthy controls. Twelve healthy controls, eight BKR, and nine TKR patients participated in the study. Maximal isometric knee strength was evaluated. 3D kinematic and kinetic analyses were conducted for level walking. The TKR knee exhibited less peak extensor torque when compared to, both the BKR and control limbs (p < 0.05). The TKR knee had less extensor moment at stance than both the BKR and control knees (p < 0.05). Both the BKR and control knees displayed larger internal rotation at stance than that of the TKR knee (p < 0.05). This study suggests that, for patients that exhibit isolated OA of the tibiofemoral joint, using a customized BKR implant is a viable treatment option and may contribute to superior mechanical advantages.

  17. Paul Callaghan luminous moments

    CERN Document Server

    Callaghan, Paul

    2013-01-01

    Acknowledged internationally for his ground-breaking scientific research in the field of magnetic resonance, Sir Paul Callaghan was a scientist and visionary with a rare gift for promoting science to a wide audience. He was named New Zealander of the Year in 2011. His death in early 2012 robbed New Zealand of an inspirational leader. Paul Callaghan: Luminous Moments brings together some of his most significant writing. Whether he describes his childhood in Wanganui, reflects on discovering the beauty of science, sets out New Zealand's future potential or discusses the experience of fa

  18. Neutron Electric Dipole Moment

    International Nuclear Information System (INIS)

    Mischke, R.E.

    2003-01-01

    The status of experiments to measure the electric dipole moment of the neutron is presented and the planned experiment at Los Alamos is described. The goal of this experiment is an improvement in sensitivity of a factor of 50 to 100 over the current limit. It has the potential to reveal new sources of T and CP violation and to challenge calculations that propose extensions to the Standard Model. The experiment employs several advances in technique to reach its goals and the feasibility of meeting these technical challenges is currently under study

  19. Total knee arthroplasty

    DEFF Research Database (Denmark)

    Schrøder, Henrik M.; Petersen, Michael M.

    2016-01-01

    Total knee arthroplasty (TKA) is a successful treatment of the osteoarthritic knee, which has increased dramatically over the last 30 years. The indication is a painful osteoarthritic knee with relevant radiographic findings and failure of conservative measures like painkillers and exercise...... surgeon seems to positively influence the rate of surgical complications and implant survival. The painful TKA knee should be thoroughly evaluated, but not revised except if a relevant indication can be established. The most frequent indications for revision are: aseptic loosening, instability, infection...

  20. Increased levels of etheno-DNA adducts and genotoxicity biomarkers of long-term exposure to pure diesel engine exhaust.

    Science.gov (United States)

    Shen, Meili; Bin, Ping; Li, Haibin; Zhang, Xiao; Sun, Xin; Duan, Huawei; Niu, Yong; Meng, Tao; Dai, Yufei; Gao, Weimin; Yu, Shanfa; Gu, Guizhen; Zheng, Yuxin

    2016-02-01

    Etheno-DNA adducts are biomarkers for assessing oxidative stress. In this study, the aim was to detect the level of etheno-DNA adducts and explore the relationship between the etheno-DNA adducts and genotoxicity biomarkers of the diesel engine exhaust (DEE)-exposed workers. We recruited 86 diesel engine testing workers with long-term exposure to DEE and 99 non-DEE-exposed workers. The urinary mono-hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) and etheno-DNA adducts (εdA and εdC) were detected by HPLC-MS/MS and UPLC-MS/MS, respectively. Genotoxicity biomarkers were also evaluated by comet assay and cytokinesis-block micronucleus assay. The results showed that urinary εdA was significantly higher in the DEE-exposed workers (p<0.001), exhibited 2.1-fold increase compared with the non-DEE-exposed workers. The levels of urinary OH-PAHs were positively correlated with the level of εdA among all the study subjects (p<0.001). Moreover, we found that the increasing level of εdA was significantly associated with the increased olive tail moment, percentage of tail DNA, or frequency of micronucleus in the study subjects (p<0.01). No significant association was observed between the εdC level and any measured genotoxicity biomarkers. In summary, εdA could serve as an indicator for DEE exposure in the human population. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Moments in time

    Directory of Open Access Journals (Sweden)

    Marc eWittmann

    2011-10-01

    Full Text Available It has been suggested that perception and action can be understood as evolving in temporal epochs or sequential processing units. Successive events are fused into units forming a unitary experience or ‘psychological present’. Studies have identified several temporal integration levels on different time scales which are fundamental for our understanding of behaviour and subjective experience. In recent literature concerning the philosophy and neuroscience of consciousness these separate temporal processing levels are not always precisely distinguished. Therefore, empirical evidence from psychophysics and neuropsychology on these distinct temporal processing levels is presented and discussed within philosophical conceptualizations of time experience. On an elementary level, one can identify a functional moment, a basic temporal building block of perception in the range of milliseconds that defines simultaneity and succession. Below a certain threshold temporal order is not perceived, individual events are processed as co-temporal. On a second level, an experienced moment, which is based on temporal integration of up to a few seconds, has been reported in many qualitatively different experiments in perception and action. It has been suggested that this segmental processing mechanism creates temporal windows that provide a logistical basis for conscious representation and the experience of nowness. On a third level of integration, continuity of experience is enabled by working-memory in the range of multiple seconds allowing the maintenance of cognitive operations and emotional feelings, leading to mental presence, a temporal window of an individual’s experienced presence.

  2. Sex differences in proximal control of the knee joint.

    Science.gov (United States)

    Mendiguchia, Jurdan; Ford, Kevin R; Quatman, Carmen E; Alentorn-Geli, Eduard; Hewett, Timothy E

    2011-07-01

    Following the onset of maturation, female athletes have a significantly higher risk for anterior cruciate ligament (ACL) injury compared with male athletes. While multiple sex differences in lower-extremity neuromuscular control and biomechanics have been identified as potential risk factors for ACL injury in females, the majority of these studies have focused specifically on the knee joint. However, increasing evidence in the literature indicates that lumbo-pelvic (core) control may have a large effect on knee-joint control and injury risk. This review examines the published evidence on the contributions of the trunk and hip to knee-joint control. Specifically, the sex differences in potential proximal controllers of the knee as risk factors for ACL injury are identified and discussed. Sex differences in trunk and hip biomechanics have been identified in all planes of motion (sagittal, coronal and transverse). Essentially, female athletes show greater lateral trunk displacement, altered trunk and hip flexion angles, greater ranges of trunk motion, and increased hip adduction and internal rotation during sport manoeuvres, compared with their male counterparts. These differences may increase the risk of ACL injury among female athletes. Prevention programmes targeted towards trunk and hip neuromuscular control may decrease the risk for ACL injuries.

  3. Sex Differences in Proximal Control of the Knee Joint

    Science.gov (United States)

    Mendiguchia, Jurdan; Ford, Kevin R.; Quatman, Carmen E.; Alentorn-Geli, Eduard; Hewett, Timothy E.

    2014-01-01

    Following the onset of maturation, female athletes have a significantly higher risk for anterior cruciate ligament (ACL) injury compared with male athletes. While multiple sex differences in lower-extremity neuromuscular control and biomechanics have been identified as potential risk factors for ACL injury in females, the majority of these studies have focused specifically on the knee joint. However, increasing evidence in the literature indicates that lumbopelvic (core) control may have a large effect on knee-joint control and injury risk. This review examines the published evidence on the contributions of the trunk and hip to knee-joint control. Specifically, the sex differences in potential proximal controllers of the knee as risk factors for ACL injury are identified and discussed. Sex differences in trunk and hip biomechanics have been identified in all planes of motion (sagittal, coronal and transverse). Essentially, female athletes show greater lateral trunk displacement, altered trunk and hip flexion angles, greater ranges of trunk motion, and increased hip adduction and internal rotation during sport manoeuvres, compared with their male counterparts. These differences may increase the risk of ACL injury among female athletes. Prevention programmes targeted towards trunk and hip neuromuscular control may decrease the risk for ACL injuries. PMID:21688868

  4. Effects of changes in skiing posture on the kinetics of the knee joint.

    Science.gov (United States)

    Koyanagi, Maki; Shino, Konsei; Yoshimoto, Yoji; Inoue, Satoru; Sato, Mutsumi; Nakata, Ken

    2006-01-01

    This study was performed to investigate the effects of changes in the skiing posture on mechanical stress across the knee joint. The aim of the present study was to establish a safer form of skiing for the prevention of injury to the anterior cruciate ligament of the knee (ACL). Ten healthy volunteers were placed on a force plate on an artificial slope, and assumed forward and backward bending postures with a single leg by changing their centre of gravity. The knee flexion angles were limited to approximately 30 degrees by orthotics in each posture. Joint moments of the lower extremity were analyzed using a motion analysis system, and the muscle activities of the lower extremity were recorded by EMG and digitised to integrated EMG in each posture. In addition, extrusion of the lower leg by the boot was measured using a force sensor sheet inserted behind the calf. We found that the extension moment of the hip and ankle joints, and muscular activity of the hamstrings were increased in forward bending, whereas the extension moment of the knee and muscular activity of the quadriceps were decreased. Conversely, the muscular activity of the quadriceps, the flexion moment of the hip, extension moment of the knee joint, and pressure of the boot were increased in backward bending, whereas muscular activity of the hamstrings was decreased. The dependency on the hamstrings increased in forward bending in a skiing posture on a slope with slight knee flexion. Therefore, forward bending seemed to be an advantageous posture for the prevention of ACL injury. Conversely, in a backward bending skiing posture, the extension moment of the knee joint produced by muscle contraction of the quadriceps also increased imbalance in the hamstrings. The results of this study suggest that the internal force exerted by the quadriceps, in addition to the passive factor of extrusion of the lower leg by the boot, may contribute to non-contact ACL injury in a backward bending posture while skiing.

  5. [Knee disarticulation and through-knee amputation].

    Science.gov (United States)

    Baumgartner, R

    2011-10-01

    A knee disarticulation or a through-knee stump is superior compared to a transfemoral stump. The thigh muscles are all preserved, and the muscle balance remains undisturbed. The range of motion of the hip joint is not limited. The bulbous shape of the stump allows full weight bearing at the stump end and can easily be fitted with a prosthesis. An amputee with a bilateral knee disarticulation is able to walk "barefoot". A more distal amputation level, e.g., an ultra-short transtibial amputation, is not possible. Important alternative to transfemoral amputations. Possible for any etiology except for Buerger-Winiwarter's disease. New indications are infected and loosened total knee replacements. Preservation of the knee joint is possible. Knee disarticulation is a very atraumatic procedure, compared to transfemoral amputations. Neither bones nor muscles have to be severed, just skin, ligaments, vessels, and nerves. Even the meniscal cartilages may be left in place to act as axial shock absorbers. The cartilage of the femur is not resected, but only bevelled in case of osteoarthritis. There are no tendon attachments or myoplastic procedures necessary. The patella remains in place and is held in position only by the retinacula. Skin closure must be performed without the slightest tension, and if possible not in the weight-bearing area. Transcondylar amputations across the femoral condyles only are indicated when there are not sufficient soft tissues for wound closure of a knee disarticulation. Alternatives as the techniques of Gritti, Klaes, and Eigler, the shortening of the femur and the Sauerbruch's rotation plasty [14] are presented and discussed. The risk of decubital ulcers is rather high. Correct bandaging of the stump is, therefore, particularly important. Prosthetic fitting is possible 3-6 weeks after surgery. The type of prosthesis depends on the amputee's activity level. The superior performance of amputees with knee disarticulations in sports prove the

  6. Approximating distributions from moments

    Science.gov (United States)

    Pawula, R. F.

    1987-11-01

    A method based upon Pearson-type approximations from statistics is developed for approximating a symmetric probability density function from its moments. The extended Fokker-Planck equation for non-Markov processes is shown to be the underlying foundation for the approximations. The approximation is shown to be exact for the beta probability density function. The applicability of the general method is illustrated by numerous pithy examples from linear and nonlinear filtering of both Markov and non-Markov dichotomous noise. New approximations are given for the probability density function in two cases in which exact solutions are unavailable, those of (i) the filter-limiter-filter problem and (ii) second-order Butterworth filtering of the random telegraph signal. The approximate results are compared with previously published Monte Carlo simulations in these two cases.

  7. Musculoskeletal MR: knee

    International Nuclear Information System (INIS)

    Staebler, A.; Glaser, C.; Reiser, M.

    2000-01-01

    Magnetic resonance imaging is the most sensitive, specific, and accurate noninvasive method for diagnosing internal derangement of the knee. During the past 15 years knowledge of pathologic conditions of the knee had evolved significantly. Beyond the basic principles of imaging knee injuries great impact was made on the understanding of indirect or collateral findings, even in rare diseases. In this article the spectrum of disorders of the knee are reviewed and an overview of the current literature is given. This includes considerations about how to achieve a high-standard MR imaging study of the knee, and principles of imaging anterior cruciate ligament and meniscal tears. A focus is put on distinct diseases including intra-articular and intraosseous ganglion cysts, iliotibial band friction syndrome, transient osteoporosis, osteonecrosis, osteochondritis dissecans, and imaging of the articular cartilage. (orig.)

  8. Characterization of hemoglobin-benzo[a]pyrene adducts

    International Nuclear Information System (INIS)

    Haugen, D.A.; Myers, S.R.

    1987-01-01

    Cultures of Syrian hamster embryo (SHE) cells were supplemented with human Hb (0.2 mM heme) and [ 3 H]BP (1 μM). After a 24-h incubation, the medium was removed and subjected to cation-exchange liquid chromatography (CM-Sepharose) to resolve hemoglobins from serum proteins in the medium. The BP-treated Hb was subjected to analysis in each of three column chromatographic systems established for isolation and characterization of human hemoglobin and its genetic and post-translationally modified variants. Results demonstrate that hemoglobin-carcinogen adducts can be resolved from native hemoglobin by established conventional and high-performance liquid chromatographic procedures, suggesting the basis for development of general approaches for isolating and characterizing hemoglobin-carcinogen adducts. The results also suggest the basis for a model system in which adducts between carcinogens and human hemoglobin are formed in cultures of mammalian cells or tissues

  9. DNA adducts: Mass spectrometry methods and future prospects

    International Nuclear Information System (INIS)

    Farmer, P.B.; Brown, K.; Tompkins, E.; Emms, V.L.; Jones, D.J.L.; Singh, R.; Phillips, D.H.

    2005-01-01

    Detection of DNA adducts is widely used for the monitoring of exposure to genotoxic carcinogens. Knowledge of the nature and amounts of DNA adducts formed in vivo also gives valuable information regarding the mutational effects that may result from particular exposures. The power of mass spectrometry (MS) to achieve qualitative and quantitative analyses of human DNA adducts has increased greatly in recent years with the development of improved chromatographic interfaces and ionisation sources. Adducts have been detected on nucleic acid bases, 2'-deoxynucleosides or 2'-deoxynucleotides, with LC-MS/MS being the favoured technique for many of these analyses. Our current applications of this technique include the determination of N7-(2-carbamoyl-2-hydroxyethyl)-guanine, which was postulated to be found as a DNA repair product in urine following exposure to acrylamide, and of 8-oxo-7,8-dihydro-2'-deoxyguanosine and 8-oxo-7,8-dihydro-2'-deoxyadenosine, as markers of oxidative damage in human lymphocyte DNA. Higher sensitivity (with a detection limit of 1-10 adducts/10 12 nucleotides) may be achieved by the use of accelerator mass spectrometry (AMS), although this requires the presence of certain isotopes, such as [ 14 C], in the material being analysed. In order to make this technique more amenable for studies of human exposure to environmental carcinogens, new postlabelling techniques, incorporating [ 14 C] into specific DNA adducts after formation, are being developed. It is expected that combining the use of advanced MS techniques with existing 32 P-postlabelling and immunochemical methodologies will contribute greatly to the understanding of the burden of human exposure to environmental carcinogens

  10. Moment invariants for particle beams

    International Nuclear Information System (INIS)

    Lysenko, W.P.; Overley, M.S.

    1988-01-01

    The rms emittance is a certain function of second moments in 2-D phase space. It is preserved for linear uncoupled (1-D) motion. In this paper, the authors present new functions of moments that are invariants for coupled motion. These invariants were computed symbolically using a computer algebra system. Possible applications for these invariants are discussed. Also, approximate moment invariants for nonlinear motion are presented

  11. Explanations pertaining to the Hip Joint Flexor Moment During the Stance Phase of Human Walking

    DEFF Research Database (Denmark)

    Simonsen, Erik B; Cappelen, Katrine L; Skorini, Ragnhild

    2012-01-01

    A hip joint flexor moment in the last half of the stance phase during walking has repeatedly been reported. However, the purpose of this moment remains uncertain and it is unknown how it is generated. Nine male subjects were instructed to walk at 4.5 km/h with their upper body in three different...... positions: normal, inclined and reclined. Net joint moments were calculated about the hip, knee and ankle joint. The peak hip joint flexor moment during late stance was significantly lower during inclined walking than in the two other conditions. During normal walking the iliacus muscle showed no or very...... weak activity and first at the transition from stance to swing. When walking reclined, a clear but rather low activity level of the iliacus muscle was seen in the first half of the stance phase, which could contribute to the hip moment. In the inclined condition the iliacus showed much increased...

  12. Effect of hip and knee position on tensor fasciae latae elongation during stretching: An ultrasonic shear wave elastography study.

    Science.gov (United States)

    Umehara, Jun; Ikezoe, Tome; Nishishita, Satoru; Nakamura, Masatoshi; Umegaki, Hiroki; Kobayashi, Takuya; Fujita, Kosuke; Ichihashi, Noriaki

    2015-12-01

    Decreased flexibility of the tensor fasciae latae is one factor that causes iliotibial band syndrome. Stretching has been used to improve flexibility or tightness of the muscle. However, no studies have investigated the effective stretching position for the tensor fasciae latae using an index to quantify muscle elongation in vivo. The aim of this study was to investigate the effects of hip rotation and knee angle on tensor fasciae latae elongation during stretching in vivo using ultrasonic shear wave elastography. Twenty healthy men participated in this study. The shear elastic modulus of the tensor fasciae latae was calculated using ultrasonic shear wave elastography. Stretching was performed at maximal hip adduction and maximal hip extension in 12 different positions with three hip rotation conditions (neutral, internal, and external rotations) and four knee angles (0°, 45°, 90°, and 135°). Two-way analysis of variance showed a significant main effect for knee angle, but not for hip rotation. The post-hoc test for knee angle indicated that the shear elastic modulus at 90° and 135° were significantly greater than those at 0° and 45°. Our results suggest that adding hip rotation to the stretching position with hip adduction and extension may have less effect on tensor fasciae latae elongation, and that stretching at >90° of knee flexion may effectively elongate the tensor fasciae latae. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Swing limb mechanics and minimum toe clearance in people with knee osteoarthritis.

    Science.gov (United States)

    Levinger, Pazit; Lai, Daniel T H; Menz, Hylton B; Morrow, Adam D; Feller, Julian A; Bartlett, John R; Bergman, Neil R; Begg, Rezaul

    2012-02-01

    Knee osteoarthritis (OA) has been shown to be a risk factor for falls. Reductions in foot clearance during the swing phase of walking can cause a trip and potentially lead to a fall. This study examined the swing phase mechanics of people with and without knee OA during walking. Minimum toe clearance (MTC) height, joint angles at the time of MTC and the influence of the angular changes of the hip, knee and ankle of the swing leg on foot clearance using sensitivity analysis were investigated in 50 knee OA participants and 28 age-matched asymptomatic controls. Although both groups had a similar MTC height (controls: 12.8±6.7 mm, knee OA: 13.4±7.0 mm), the knee OA group used a different strategy to achieve the same foot clearance, as evidenced by greater knee flexion (52.5±5.3° vs 49.4±4.8°, p=0.007), greater hip abduction (-3.6±3.3° vs -1.8±3.3°, p=0.03) and less ankle adduction (2.8±1.9° vs 4.2±2.1°, p=0.01). MTC height was comparable between the groups, however a different swing phase mechanism was used by the knee OA. Although adequate MTC is an important component of safe locomotion, it does not appear to be impaired in people with knee OA. Other factors, such as inadequate responses to postural perturbation, may be responsible for falls in this group. Copyright © 2011 Elsevier B.V. All rights reserved.

  14. Face recognition using Krawtchouk moment

    Indian Academy of Sciences (India)

    Zernike moment to enhance the discriminant nature (Pang et al 2006). ... was proposed which is partially invariant to changes in the local image samples, ... tigate the Krawtchouk discrete orthogonal moment-based feature ..... in scale have been achieved by changing the distance between the person and the video camera.

  15. Variational approach to magnetic moments

    Energy Technology Data Exchange (ETDEWEB)

    Lipparini, E; Stringari, S; Traini, M [Dipartimento di Matematica e Fisica, Libera Universita di Trento, Italy

    1977-11-07

    Magnetic moments in nuclei with a spin unsaturated core plus or minus an extra nucleon have been studied using a restricted Hartree-Fock approach. The method yields simple explicit expressions for the deformed ground state and for magnetic moments. Different projection techniques of the HF scheme have been discussed and compared with perturbation theory.

  16. On fractional Fourier transform moments

    NARCIS (Netherlands)

    Alieva, T.; Bastiaans, M.J.

    2000-01-01

    Based on the relation between the ambiguity function represented in a quasi-polar coordinate system and the fractional power spectra, the fractional Fourier transform moments are introduced. Important equalities for the global second-order fractional Fourier transform moments are derived and their

  17. Neutron Electric Dipole Moment Experiments

    OpenAIRE

    Peng, Jen-Chieh

    2008-01-01

    The neutron electric dipole moment (EDM) provides unique information on CP violation and physics beyond the Standard Model. We first review the history of experimental searches for neutron electric dipole moment. The status of future neutron EDM experiments, including experiments using ultra-cold neutrons produced in superfluid helium, will then be presented.

  18. Comparison of estimated dietary intake of acrylamide with hemoglobin adducts of acrylamide and glycidamide

    DEFF Research Database (Denmark)

    Bjellaas, Thomas; Olesen, Pelle Thonning; Frandsen, Henrik Lauritz

    2007-01-01

    , a significant positive correlation was found between the AA-Hb adduct concentration and the intake of chips/snacks and crisp bread. GA-Hb adduct did not correlate with consumption of any of the main food groups. Neither AA-Hb nor GA-Hb adduct concentration correlated with total dietary intake of AA...

  19. 40 CFR 721.3680 - Ethylene oxide adduct of fatty acid ester with pentaerythritol.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Ethylene oxide adduct of fatty acid... New Uses for Specific Chemical Substances § 721.3680 Ethylene oxide adduct of fatty acid ester with... identified generically as ethylene oxide adduct of fatty acid ester with pentaerythritol (PMN P-91-442) is...

  20. Magnetic Moment of $^{59}$Cu

    CERN Multimedia

    2002-01-01

    Experiment IS358 uses the intense and pure beams of copper isotopes provided by the ISOLDE RILIS (resonance ionization laser ion source). The isotopes are implanted and oriented in the low temperature nuclear orientation set-up NICOLE. Magnetic moments are measured by $\\beta$-NMR. Copper (Z=29), with a single proton above the proton-magic nickel isotopes provides an ideal testground for precise shell model calculations of magnetic moments and their experimental verification. In the course of our experiments we already determined the magnetic moments of $^{67}$Ni, $^{67}$Cu, $^{68g}$Cu, $^{69}$Cu and $^{71}$Cu which provide important information on the magicity of the N=40 subshell closure. In 2001 we plan to conclude our systematic investigations by measuring the magnetic moment of the neutron-deficient isotope $^{59}$Cu. This will pave the way for a subsequent study of the magnetic moment of $^{57}$Cu with a complementary method.

  1. Theoretical investigations on the formation of nitrobenzanthrone-DNA adducts.

    Science.gov (United States)

    Arlt, Volker M; Phillips, David H; Reynisson, Jóhannes

    2011-09-07

    3-Nitrobenzanthrone (3-NBA) is a potent mutagen and suspected human carcinogen identified in diesel exhaust. The thermochemical formation cascades were calculated for six 3-NBA-derived DNA adducts employing its arylnitrenium ion as precursor using density functional theory (DFT). Clear exothermic pathways were found for four adducts, i.e., 2-(2'-deoxyadenosin-N(6)-yl)-3-aminobenzanthrone, 2-(2'-deoxyguanosin-N(2)-yl)-3-aminobenzanthrone, N-(2'-deoxyguanosin-8-yl)-3-aminobenzanthrone and 2-(2'-deoxyguanosin-8-yl)-3-aminobenzanthrone. All four have been observed to be formed in cell-free experimental systems. The formation of N-(2'-deoxyadenosin-8-yl)-3-aminobenzanthrone is predicted to be not thermochemically viable explaining its absence in either in vitro or in vivo model systems. However, 2-(2'-deoxyadenosin-8-yl)-3-aminobenzanthrone, can be formed, albeit not as a major product, and is a viable candidate for an unknown adenine adduct observed experimentally. 2-nitrobenzanthrone (2-NBA), an isomer of 3-NBA, was also included in the calculations; it has a higher abundance in ambient air than 3-NBA, but a much lower genotoxic potency. Similar thermochemical profiles were obtained for the calculated 2-NBA-derived DNA adducts. This leads to the conclusion that enzymatic activation as well as the stability of its arylnitrenium ion are important determinants of 2-NBA genotoxicity.

  2. Mass spectrometric analyses of organophosphate insecticide oxon protein adducts.

    Science.gov (United States)

    Thompson, Charles M; Prins, John M; George, Kathleen M

    2010-01-01

    Organophosphate (OP) insecticides continue to be used to control insect pests. Acute and chronic exposures to OP insecticides have been documented to cause adverse health effects, but few OP-adducted proteins have been correlated with these illnesses at the molecular level. Our aim was to review the literature covering the current state of the art in mass spectrometry (MS) used to identify OP protein biomarkers. We identified general and specific research reports related to OP insecticides, OP toxicity, OP structure, and protein MS by searching PubMed and Chemical Abstracts for articles published before December 2008. A number of OP-based insecticides share common structural elements that result in predictable OP-protein adducts. The resultant OP-protein adducts show an increase in molecular mass that can be identified by MS and correlated with the OP agent. Customized OP-containing probes have also been used to tag and identify protein targets that can be identified by MS. MS is a useful and emerging tool for the identification of proteins that are modified by activated organophosphate insecticides. MS can characterize the structure of the OP adduct and also the specific amino acid residue that forms the key bond with the OP. Each protein that is modified in a unique way by an OP represents a unique molecular biomarker that with further research can lead to new correlations with exposure.

  3. Thermodynamic parameters for polyether adducts with neutral molecules

    International Nuclear Information System (INIS)

    Spencer, J.N.; Zafar, A.I.; Ganunis, T.F.

    1992-01-01

    Using calorimetry, thermodynamic parameters for the interaction of neutral molecules with polyether adducts are determined. When compared to its analogous acyclic ether, no macrocyclic effect is observed for 12-crown-4. The ether's collective oxygen atoms' action determines interaction with acetonitrile and malononitrile, with dimethyltin dichloride having a specific oxygen-binding site. 14 refs., 1 tab

  4. Vaporization of GaI3Py adduct

    International Nuclear Information System (INIS)

    Timoshkina, A.Yu.; Grigor'ev, A.A.; Suvorov, A.V.

    1995-01-01

    Processes of GaI 3 Py complex vaporization have been studied by mass-spectrometric, tensimetric and calorimetric methods. It is shown that adduct transformation into vapour is accompanied by its thermal dissociation. Thermodynamic characteristics of evaporation and dissociation of GaI 3 Py complex have been obtained. 14 refs., 2 figs., 6 tabs

  5. Conformations of stereoisomeric base adducts to 4-hydroxyequilenin.

    Science.gov (United States)

    Ding, Shuang; Shapiro, Robert; Geacintov, Nicholas E; Broyde, Suse

    2003-06-01

    Exposure to estrogen through estrogen replacement therapy increases the risk of women developing cancer in hormone sensitive tissues. Premarin (Wyeth), which has been the most frequent choice for estrogen replacement therapy in the United States, contains the equine estrogens equilin and equilenin as major components. 4-Hydroxyequilenin (4-OHEN) is a phase I metabolite of both of these substances. This catechol estrogen autoxidizes to potent cytotoxic quinoids that can react with dG, dA, and dC to form unusual stereoisomeric cyclic adducts (Bolton, J. L., et al. (1998) Chem. Res. Toxicol. 11, 1113-1127). Like other bulky DNA adducts, these lesions may exhibit different susceptibilities to DNA repair and mutagenic potential, if not repaired in a structure-dependent manner. To ultimately gain insights into structure-function relationships, we computed conformations of stereoisomeric guanine, adenine, and cytosine base adducts using density functional theory. We find near mirror image conformations in stereoisomer adduct pairs for each modified base, suggesting opposite orientations with respect to the 5' --> 3' direction of the modified strand when the stereoisomer pairs are incorporated into duplex DNA. Such opposite orientations could cause stereoisomer pairs of lesions to respond differently to DNA replication and repair enzymes.

  6. The fate of H atom adducts to 3'-uridine monophosphate.

    Science.gov (United States)

    Wang, Ran; Zhang, Ru Bo; Eriksson, Leif A

    2010-07-29

    The stabilities of the adducts deriving from H free radical addition to the O2, O4, and C5 positions of 3'-uridine monophosphate (3'UMP) are studied by the hybrid density functional B3LYP approach. Upon H atom addition at the O2 position, a concerted low-barrier proton-transfer process will initially occur, followed by the potential ruptures of the N-glycosidic or beta-phosphate bonds. The rupture barriers are strongly influenced by the rotational configuration of the phosphate group at the 3' terminal, and are influenced by bulk solvation effects. The O4-H adduct has the highest thermal stability, as the localization of the unpaired electron does not enable cleavage of either the C1'-N1 or the C3'-O(P) bonds. For the most stable adduct, with H atom added to the C5 position, the rate-controlled step is the H2'a abstraction by the C6 radical site, after which the subsequent strand rupture reactions proceed with low barriers. The main unpaired electron densities are presented for the transient species. Combined with previous results, it is concluded that the H atom adducts are more facile to drive the strand scission rather than N-glycosidic bond ruptures within the nucleic acid bases.

  7. Fullerene–Carbene Lewis Acid–Base Adducts

    KAUST Repository

    Li, Huaping; Risko, Chad; Seo, Jung Hwa; Campbell, Casey; Wu, Guang; Brédas, Jean-Luc; Bazan, Guillermo C.

    2011-01-01

    The reaction between a bulky N-heterocylic carbene (NHC) and C60 leads to the formation of a thermally stable zwitterionic Lewis acid-base adduct that is connected via a C-C single bond. Low-energy absorption bands with weak oscillator strengths

  8. Metal-isonitrile adducts for preparing radionuclide complexes

    International Nuclear Information System (INIS)

    Carpenter, A.P.; Linder, K.E.; Maheu, L.J.; Patz, M.A.; Thompson, J.S.; Tulip, T.H.; Subramanyam, V.

    1988-01-01

    An method for preparing a coordination complex of isonitrile ligand and a radioisotope of Te, Ru, Co, Pt, Re, Os, Ir, W, Re, Cr, Mo, Mn, Ni, Rh, Nb and Ta from a non-radioactive metal adduct of the isonitrile

  9. Characterization of trypsin-derived peptides acrylamide-adducted hemoglobin

    International Nuclear Information System (INIS)

    Springer, D.L.; Goheen, S.C.; Edmonds, C.G.; McCulloch, M.; Sylvester, D.M.; Sander, C.; Bull, R.J.

    1991-01-01

    Even though there are a number of sources for human exposure to acrylamide, reliable biomarkers of exposure are not available. In an effort to develop such a biomarker, the authors are characterizing peptides derived from trypsin digests of acrylamide-adducted hemoglobin. For this, radiolabeled acrylamide was incubated with this, radiolabeled acrylamide was incubated with purified human hemoglobin (Ao) and decomposition products removed by dialysis. When the adducted hemoglobin was separated by reverse-phase HPLC, radioactivity eluted with the α and β subunits, suggesting covalent binding. Digestion of individual subunits with trypsin followed by reverse phase HPLC, indicated that most of the radioactivity associated with the α subunit co-eluted with a single peptide. Similar results were observed for the β subunit except that significant amounts of radioactivity eluted with the solvent front, suggesting that radioactivity was released by trypsin digestion. Currently, these preparation are under further characterization by electrospray ionization mass spectrometry. This approach will aid in the identification of the adducted will aid in the identification of the adducted peptide and subsequent preparation of an acrylamide-specific antibody

  10. Joint angles of the ankle, knee, and hip and loading conditions during split squats.

    Science.gov (United States)

    Schütz, Pascal; List, Renate; Zemp, Roland; Schellenberg, Florian; Taylor, William R; Lorenzetti, Silvio

    2014-06-01

    The aim of this study was to quantify how step length and the front tibia angle influence joint angles and loading conditions during the split squat exercise. Eleven subjects performed split squats with an additional load of 25% body weight applied using a barbell. Each subject's movements were recorded using a motion capture system, and the ground reaction force was measured under each foot. The joint angles and loading conditions were calculated using a cluster-based kinematic approach and inverse dynamics modeling respectively. Increases in the tibia angle resulted in a smaller range of motion (ROM) of the front knee and a larger ROM of the rear knee and hip. The external flexion moment in the front knee/hip and the external extension moment in the rear hip decreased as the tibia angle increased. The flexion moment in the rear knee increased as the tibia angle increased. The load distribution between the legs changed squat execution was varied. Our results describing the changes in joint angles and the resulting differences in the moments of the knee and hip will allow coaches and therapists to adapt the split squat exercise to the individual motion and load demands of athletes.

  11. Knee joint replacement

    Science.gov (United States)

    ... to make everyday tasks easier. Practice using a cane, walker , crutches , or a wheelchair correctly. On the ... ask your doctor Knee joint replacement - discharge Preventing falls Preventing falls - what to ask your doctor Surgical ...

  12. 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.

  13. CT of the knee

    International Nuclear Information System (INIS)

    Ghelman, B.

    1987-01-01

    CT can be combined with arthrography of the knee to study the following abnormalities: meniscal tears and cysts, synovial plicae, chondromalacia patellae, and osteochondritis dissecans. The CT-arthrogram images present abnormalities in a manner that resembles the ''in situ'' surgical findings, allowing management decisions to be made with greater confidence. The CT techniques for imaging the knee after arthrography are discussed, as is the use of plain CT

  14. Dashboard (in the) knee.

    Science.gov (United States)

    Patel, M S; Qureshi, A A; Green, T P

    2015-03-01

    We present the case of a 19-year-old individual presenting to an orthopaedic outpatient clinic several months following a dashboard knee injury during a road traffic accident with intermittent mechanical symptoms. Despite unremarkable examination findings and normal magnetic resonance imaging, the patient was identified subsequently as having an intra-articular plastic foreign body consistent with a piece of dashboard on arthroscopic knee assessment, the retrieval of which resulted in a complete resolution of symptoms.

  15. Prevalent knee pain and sport

    DEFF Research Database (Denmark)

    Hahn, Thomas; Foldspang, Anders

    1998-01-01

    STUDY OBJECTIVE: To estimate the prevalence of knee pain in active athletes and to investigate potential associations to type, amount and duration of sports participation. MEASUREMENTS: 339 athletes gave information about occupation, sports activity and different features of knee pain, based...... on a self-filled questionnaire. MAIN RESULTS: The prevalence of knee pain within the preceding 12 months, constant or recurrent knee pain, absence from sport and absence from work due to knee pain, was 54%, 34%, 19% and 4%, respectively. Knee pain was positively associated with years of jogging...... and with weekly hours of participation in competitive gymnastics but negatively with weekly hours of tennis. Constant or recurrent knee pain was positively associated with years of swimming. Absence from sport due to knee pain was positively associated with weekly hours of soccer participation. CONCLUSIONS: Knee...

  16. Experimental quadriceps muscle pain impairs knee joint control during walking

    DEFF Research Database (Denmark)

    Henriksen, Marius; Alkjaer, Tine; Lund, Hans

    2007-01-01

    Pain is a cardinal symptom in musculoskeletal diseases involving the knee joint, and aberrant movement patterns and motor control strategies are often present in these patients. However, the underlying neuromuscular mechanisms linking pain to movement and motor control are unclear. To investigate...... the functional significance of muscle pain on knee joint control during walking, three-dimensional gait analyses were performed before, during, and after experimentally induced muscle pain by means of intramuscular injections of hypertonic saline (5.8%) into vastus medialis (VM) muscle of 20 healthy subjects....... Isotonic saline (0.9%) was used as control. Surface electromyography (EMG) recordings of VM, vastus lateralis (VL), biceps femoris, and semitendinosus muscles were synchronized with the gait analyses. During experimental muscle pain, the loading response phase peak knee extensor moments were attenuated...

  17. Taking care of your new knee joint

    Science.gov (United States)

    Knee arthroplasty - precautions; Knee replacement - precautions ... After you have knee replacement surgery , you will need to be careful about how you move your knee, especially for the first few ...

  18. Photochemistry of psoralen-DNA adducts, biological effects of psoralen-DNA adducts, applications of psoralen-DNA photochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Yun-bo

    1988-03-01

    This thesis consists of three main parts and totally eight chapters. In Part I, The author will present studies on the photochemistry of psoralen-DNA adducts, specifically, the wavelength dependencies for the photoreversals of thymidine-HMT (4'-hydroxymethyl-4, 5', 8-trimenthylpsoralen) monoadducts and diadduct and the same adducts incorporated in DNA helices and the wavelength dependecies for the photocrossslinking of thymidine-HMT monoadducts in double-stranded helices. In Part II, The author will report some biological effects of psoralen-DNA adducts, i.e., the effects on double-stranded DNA stability, DNA structure, and transcription by E. coli and T7 RNA polymerases. Finally, The author will focus on the applications of psoralen-DNA photochemistry to investigation of protein-DNA interaction during transcription, which includes the interaction of E. coli and T7 RNA polymerases with DNA in elongation complexes arrested at specific psoralen-DNA adduct sites as revealed by DNase I footprinting experiments. 123 refs., 52 figs., 12 tabs.

  19. Photochemistry of psoralen-DNA adducts, biological effects of psoralen-DNA adducts, applications of psoralen-DNA photochemistry

    International Nuclear Information System (INIS)

    Shi, Yun-bo.

    1988-03-01

    This thesis consists of three main parts and totally eight chapters. In Part I, The author will present studies on the photochemistry of psoralen-DNA adducts, specifically, the wavelength dependencies for the photoreversals of thymidine-HMT (4'-hydroxymethyl-4, 5', 8-trimenthylpsoralen) monoadducts and diadduct and the same adducts incorporated in DNA helices and the wavelength dependecies for the photocrossslinking of thymidine-HMT monoadducts in double-stranded helices. In Part II, The author will report some biological effects of psoralen-DNA adducts, i.e., the effects on double-stranded DNA stability, DNA structure, and transcription by E. coli and T7 RNA polymerases. Finally, The author will focus on the applications of psoralen-DNA photochemistry to investigation of protein-DNA interaction during transcription, which includes the interaction of E. coli and T7 RNA polymerases with DNA in elongation complexes arrested at specific psoralen-DNA adduct sites as revealed by DNase I footprinting experiments. 123 refs., 52 figs., 12 tabs

  20. Environmental, Dietary, Maternal, and Fetal Predictors of Bulky DNA Adducts in Cord Blood

    DEFF Research Database (Denmark)

    Pedersen, Marie; Mendez, Michelle A; Schoket, Bernadette

    2015-01-01

    and drinking-water disinfection by-products, mainly trihalomethanes (THMs), were available for a large proportion of the study population. RESULTS: Greek and Spanish neonates had higher adduct levels than the northern European neonates [median, 12.1 (n = 179) vs. 6.8 (n = 332) adducts per 108 nucleotides, p...... with higher adduct levels in adjusted models. Exposure to fine particulate matter and nitrogen dioxide was associated with significantly higher adducts in the Danish subsample only. Overall, the pooled results for THMs in water show no evidence of association with adduct levels; however, there are country...

  1. Formation of DNA adducts in mouse tissues after 1-nitropyrene administration

    International Nuclear Information System (INIS)

    Mitchell, C.E.

    1986-01-01

    DNA adducts were isolated and characterized in mouse lung, liver and kidney after intratracheal instillation of [ 3 H]-1-nitropyrene (1-NP). HPLC analysis of the enzymatically digested DNA indicated the presence of multiple DNA adducts in mouse lung, liver and kidney. These results indicate that DNA adducts of 1-NP are formed in mouse lung, liver and kidney after intratracheal instillation of 1-NP; the HPLC profiles of the multiple adducts suggests that adducts may be formed via metabolic pathways that involve both nitroreduction and ring-oxidation. 6 references, 1 figure

  2. 32P-postlabeling DNA adduct assay: cigarette smoke-induced dna adducts in the respiratory and nonrespiratory rat tissues. Book chapter

    International Nuclear Information System (INIS)

    Gupta, R.C.; Gairola, C.G.

    1990-01-01

    An analysis of the tissue DNA adducts in rats by the sensitive (32)p-postlabeling assay showed one to eight detectable DNA adducts in lung, trachea, larynx, heart and bladder of the sham controls. Chronic exposure of animals to mainstream cigarette smoke showed a remarkable enhancement of most adducts in the lung and heart DNA. Since cigarette smoke contains several thousand chemicals and a few dozen of them are known or potential carcinogens, the difference between the DNA adducts of nasal and the other tissues may reflect the diversity of reactive constituents and their differential absorption in different tissues. In comparison to the lung DNA adducts, the adducts in nasal DNA were less hydrophobic. Identity of the predominant adducts was further investigated by comparison with several reference DNA adducts from 10 PAH and aromatic amines. Since some of these chemicals are present in cigarette smoke, the results suggest that these constituents of cigarette smoke may not be directly responsible for formation of DNA adducts in the lung and heart of the smoke-exposed animals

  3. On the baryon magnetic moments

    International Nuclear Information System (INIS)

    Ferreira, P.L.

    1976-01-01

    In the context of quark confinement ideas, the baryon magnetic moments are calculated by assuming a SU(3) breaking due to the inequalities of the quark masses (m sub(p) different m sub(n) different m lambda ). The modified SU(6) result for the ratio of the magnetic moments of the neutron and proton is obtained. The p-quark is found heavier than the n-quark by circa 15 MeV. and alternative way of evaluating the baryon magnetic moments by means of simple physical considerations based on the properties of the SU(6) baryon S-waves functions is given

  4. Moment Magnitude discussion in Austria

    Science.gov (United States)

    Weginger, Stefan; Jia, Yan; Hausmann, Helmut; Lenhardt, Wolfgang

    2017-04-01

    We implemented and tested the Moment Magnitude estimation „dbmw" from the University of Trieste in our Antelope near real-time System. It is used to get a fast Moment Magnitude solutions and Ground Motion Parameter (PGA, PGV, PSA 0.3, PSA 1.0 and PSA 3.0) to calculate Shake and Interactive maps. A Moment Magnitude Catalogue was generated and compared with the Austrian Earthquake Catalogue and all available Magnitude solution of the neighbouring agencies. Relations of Mw to Ml and Ground Motion to Intensity are presented.

  5. Magnetic moment of 33Cl

    International Nuclear Information System (INIS)

    Matsuta, K.; Arimura, K.; Nagatomo, T.; Akutsu, K.; Iwakoshi, T.; Kudo, S.; Ogura, M.; Takechi, M.; Tanaka, K.; Sumikama, T.; Minamisono, K.; Miyake, T.; Minamisono, T.; Fukuda, M.; Mihara, M.; Kitagawa, A.; Sasaki, M.; Kanazawa, M.; Torikoshi, M.; Suda, M.; Hirai, M.; Momota, S.; Nojiri, Y.; Sakamoto, A.; Saihara, M.; Ohtsubo, T.; Alonso, J.R.; Krebs, G.F.; Symons, T.J.M.

    2004-01-01

    The magnetic moment of 33 Cl (Iπ=3/2+, T1/2=2.51s) has been re-measured precisely by β-NMR method. The obtained magnetic moment |μ|=0.7549(3)μN is consistent with the old value 0.7523(16)μN, but is 5 times more accurate. The value is well reproduced by the shell model calculation, μSM=0.70μN. Combined with the magnetic moment of the mirror partner 33 S, the nuclear matrix elements , , , and were derived

  6. Moment methods with effective nuclear Hamiltonians; calculations of radial moments

    International Nuclear Information System (INIS)

    Belehrad, R.H.

    1981-02-01

    A truncated orthogonal polynomial expansion is used to evaluate the expectation value of the radial moments of the one-body density of nuclei. The expansion contains the configuration moments, , , and 2 >, where R/sup (k)/ is the operator for the k-th power of the radial coordinate r, and H is the effective nuclear Hamiltonian which is the sum of the relative kinetic energy operator and the Bruckner G matrix. Configuration moments are calculated using trace reduction formulae where the proton and neutron orbitals are treated separately in order to find expectation values of good total isospin. The operator averages are taken over many-body shell model states in the harmonic oscillator basis where all particles are active and single-particle orbitals through six major shells are included. The radial moment expectation values are calculated for the nuclei 16 O, 40 Ca, and 58 Ni and find that is usually the largest term in the expansion giving a large model space dependence to the results. For each of the 3 nuclei, a model space is found which gives the desired rms radius and then we find that the other 5 lowest moments compare favorably with other theoretical predictions. Finally, we use a method of Gordon (5) to employ the lowest 6 radial moment expectation values in the calculation of elastic electron scattering from these nuclei. For low to moderate momentum transfer, the results compare favorably with the experimental data

  7. Hip abduction-adduction strength and one-leg hop tests: test-retest reliability and relationship to function in elite ice hockey players.

    Science.gov (United States)

    Kea, J; Kramer, J; Forwell, L; Birmingham, T

    2001-08-01

    Single group, test-retest. To determine: (1) hip abduction and adduction torques during concentric and eccentric muscle actions, (2) medial and lateral one-leg hop distances, (3) the test-retest reliability of these measurements, and (4) the relationship between isokinetic measures of hip muscle strength and hop distances in elite ice hockey players. The skating motion used in ice hockey requires strong contractions of the hip and knee musculature. However, baseline scores for hip strength and hop distances, their test-retest reliability, and measures of the extent to which these tests are related for this population are not available. The dominant leg of 27 men (mean age 20 +/- 3 yrs) was tested on 2 occasions. Hip abduction and adduction movements were completed at 60 degrees.s(-1) angular velocity, with the subject lying on the non-test side and the test leg moving vertically in the subject's coronal plane. One-leg hops requiring jumping from and landing on the same leg without losing balance were completed in the medial and lateral directions. Hip adduction torques were significantly greater than abduction torques during both concentric and eccentric muscle actions, while no significant difference was observed between medial and lateral hop distances. Although hop test scores produced excellent ICCs (> 0.75) when determined using scores on 1 occasion, torques needed to be averaged over 2 test occasions to reach this level. Correlations between the strength and hop tests ranged from slight to low (r = -0.26 to 0.27) and were characterized by wide 95% confidence intervals (-0.54 to 0.61). Isokinetic tests of hip abduction and adduction did not provide a strong indication of performance during sideways hop tests. Although isokinetic tests can provide a measure of muscular strength under specific test conditions, they should not be relied upon as a primary indicator of functional abilities or readiness to return to activity.

  8. On the role of the patella, ACL and joint contact forces in the extension of the knee.

    Directory of Open Access Journals (Sweden)

    Daniel J Cleather

    Full Text Available Traditional descriptions of the knee suggest that the function of the patella is to facilitate knee extension by increasing the moment arm of the quadriceps muscles. Through modelling and evidence from the literature it is shown in this paper that the presence of the patella makes the ability of the quadriceps to rotate the thigh greater than their ability to rotate the tibia. Furthermore, this difference increases as the knee is flexed, thus demonstrating a pattern that is consistent with many human movements. This paper also shows that the anterior cruciate ligament plays a previously unheralded role in extending the shank and that translation at the tibiofemoral and patellofemoral joints is important in improving the capacity for thigh rotation when the knee is flexed. This study provides new insights as to how the structure of the knee is adapted to its purpose and illustrates how the functional anatomy of the knee contributes to its extension function.

  9. Clinical practice guidelines for rest orthosis, knee sleeves, and unloading knee braces in knee osteoarthritis.

    Science.gov (United States)

    Beaudreuil, Johann; Bendaya, Samy; Faucher, Marc; Coudeyre, Emmanuel; Ribinik, Patricia; Revel, Michel; Rannou, François

    2009-12-01

    To develop clinical practice guidelines concerning the use of bracing--rest orthosis, knee sleeves and unloading knee braces--for knee osteoarthritis. The French Physical Medicine and Rehabilitation Society (SOFMER) methodology, associating a systematic literature review, collection of everyday clinical practice, and external review by multidisciplinary expert panel, was used. Few high-level studies of bracing for knee osteoarthritis were found. No evidence exists for the effectiveness of rest orthosis. Evidence for knee sleeves suggests that they decrease pain in knee osteoarthritis, and their use is associated with subjective improvement. These actions do not appear to depend on a local thermal effect. The effectiveness of knee sleeves for disability is not demonstrated for knee osteoarthritis. Short- and mid-term follow-up indicates that valgus knee bracing decreases pain and disability in medial knee osteoarthritis, appears to be more effective than knee sleeves, and improves quality of life, knee proprioception, quadriceps strength, and gait symmetry, and decreases compressive loads in the medial femoro-tibial compartment. However, results of response to valgus knee bracing remain inconsistent; discomfort and side effects can result. Thrombophlebitis of the lower limbs has been reported with the braces. Braces, whatever kind, are infrequently prescribed in clinical practice for osteoarthritis of the lower limbs. Modest evidence exists for the effectiveness of bracing--rest orthosis, knee sleeves and unloading knee braces--for knee osteoarthritis, with only low level recommendations for its use. Braces are prescribed infrequently in French clinical practice for osteoarthritis of the knee. Randomized clinical trials concerning bracing in knee osteoarthritis are still necessary.

  10. Detection of Adriamycin-DNA adducts by accelerator mass spectrometry at clinically relevant Adriamycin concentrations.

    Science.gov (United States)

    Coldwell, Kate E; Cutts, Suzanne M; Ognibene, Ted J; Henderson, Paul T; Phillips, Don R

    2008-09-01

    Limited sensitivity of existing assays has prevented investigation of whether Adriamycin-DNA adducts are involved in the anti-tumour potential of Adriamycin. Previous detection has achieved a sensitivity of a few Adriamycin-DNA adducts/10(4) bp DNA, but has required the use of supra-clinical drug concentrations. This work sought to measure Adriamycin-DNA adducts at sub-micromolar doses using accelerator mass spectrometry (AMS), a technique with origins in geochemistry for radiocarbon dating. We have used conditions previously validated (by less sensitive decay counting) to extract [(14)C]Adriamycin-DNA adducts from cells and adapted the methodology to AMS detection. Here we show the first direct evidence of Adriamycin-DNA adducts at clinically-relevant Adriamycin concentrations. [(14)C]Adriamycin treatment (25 nM) resulted in 4.4 +/- 1.0 adducts/10(7) bp ( approximately 1300 adducts/cell) in MCF-7 breast cancer cells, representing the best sensitivity and precision reported to date for the covalent binding of Adriamycin to DNA. The exceedingly sensitive nature of AMS has enabled over three orders of magnitude increased sensitivity of Adriamycin-DNA adduct detection and revealed adduct formation within an hour of drug treatment. This method has been shown to be highly reproducible for the measurement of Adriamycin-DNA adducts in tumour cells in culture and can now be applied to the detection of these adducts in human tissues.

  11. Analysis of in vitro and in vivo function of total knee replacements using dynamic contact models

    Science.gov (United States)

    Zhao, Dong

    Despite the high incidence of osteoarthritis in human knee joint, its causes remain unknown. Total knee replacement (TKR) has been shown clinically to be effective in restoring the knee function. However, wear of ultra-high molecular weight polyethylene has limited the longevity of TKRs. To address these important issues, it is necessary to investigate the in vitro and in vivo function of total knee replacements using dynamic contact models. A multibody dynamic model of an AMTI knee simulator was developed. Incorporating a wear prediction model into the contact model based on elastic foundation theory enables the contact surface to take into account creep and wear during the dynamic simulation. Comparisons of the predicted damage depth, area, and volume lost with worn retrievals from a physical machine were made to validate the model. In vivo tibial force distributions during dynamic and high flexion activities were investigated using the dynamic contact model. In vivo medial and lateral contact forces experienced by a well-aligned instrumented knee implant, as well as upper and lower bounds on contact pressures for a variety of activities were studied. For all activities, the predicted medial and lateral contact forces were insensitive to the selected material model. For this patient, the load split during the mid-stance phase of gait and during stair is more equal than anticipated. The external knee adduction torque has been proposed as a surrogate measure for medial compartment load during gait. However, a direct link between these two quantities has not been demonstrated using in vivo measurement of medial compartment load. In vivo data collected from a subject with an instrumented knee implant were analyzed to evaluate this link. The subject performed five different overground gait motions (normal, fast, slow, wide, and toe out) while instrumented implant, video motion, and ground reaction data were simultaneously collected. The high correlation coefficient

  12. Fast computation of Krawtchouk moments

    Czech Academy of Sciences Publication Activity Database

    Honarvar Shakibaei Asli, B.; Flusser, Jan

    2014-01-01

    Roč. 288, č. 1 (2014), s. 73-86 ISSN 0020-0255 R&D Projects: GA ČR GAP103/11/1552 Institutional support: RVO:67985556 Keywords : Krawtchouk polynomial * Krawtchouk moment * Geometric moment * Impulse response * Fast computation * Digital filter Subject RIV: JD - Computer Applications, Robotics Impact factor: 4.038, year: 2014 http://library.utia.cas.cz/separaty/2014/ZOI/flusser-0432452.pdf

  13. Sex-Based Differences in Knee Kinetics With Anterior Cruciate Ligament Strain on Cadaveric Impact Simulations

    Science.gov (United States)

    Schilaty, Nathan D.; Bates, Nathaniel A.; Nagelli, Christopher; Krych, Aaron J.; Hewett, Timothy E.

    2018-01-01

    Background: Females are at an increased risk of sustaining noncontact knee ligament injuries as compared with their male counterparts. The kinetics that load the anterior cruciate ligament (ACL) are still under dispute in the literature. Purpose/Hypothesis: The purpose of this study was to determine whether there are differences in knee kinetics between the sexes that lead to greater ACL strain in females when similar external loads are applied during a simulated drop vertical jump landing task. It was hypothesized that female limbs would demonstrate significant differences in knee abduction moment that predispose females to ACL injury when compared with males. Study Design: Controlled laboratory study. Methods: Motion analysis data of 67 athletes who performed a drop vertical jump were collected. The kinematic and kinetic data were used to categorize tertiles of relative risk, and these values were input into a cadaveric impact simulator to assess ligamentous loads during the simulated landing task. Uni- and multiaxial load cells and differential variable reluctance transducer strain sensors were utilized to collect kinetic data and maximum ACL strain for analysis. Conditions of external loads applied to the cadaveric limbs were systematically varied and randomized. Data were analyzed with 2-way repeated-measures analysis of variance and the Fisher exact test. Results: Five kinetic parameters were evaluated. Of the 5 kinetic variables, only knee abduction moment (KAM) demonstrated significant differences in females as compared with males (F 1,136 = 4.398, P = .038). When normalized to height and weight, this difference between males and females increased in significance (F 1,136 = 7.155, P = .008). Compared with males, females exhibited a 10.3-N·m increased knee abduction torque at 66 milliseconds postimpact and a 22.3-N·m increased abduction torque at 100 milliseconds postimpact. For loading condition, the condition of “maximum ACL strain” demonstrated a

  14. Knee arthrography today

    International Nuclear Information System (INIS)

    Otto, H.; Kallenberger, R.

    1987-01-01

    The role of knee arthrography today is demonstrated and technical problems are discussed. Among a lot of variants the position of the patient and the choice of contrast media play a great part concerning the result of the examination. Mild complications occur in 0.25% of the examinations, severe and live threatening complications are extremely rare. Diagnosis of meniscal lesions is most important for knee arthrography; arthroscopy and arthrography are complementary examinations and not mutually exclusive, they achieve combined an accuracy of 97-98%. In the same way arthrography is able to evaluate the condropathy of the femoro-tibial joint, whereas accuracy of arthroscopy in the diagnosis of patellar chondropathy is much higher. There is a great reliability of arthrography regarding the evaluation of lesions of the capsule, but accuracy in lesions of the cruciate ligaments is low. Arthrography is very suitable for evaluation of Baker-cysts, since indications for almost occuring internal derangement of the knee are even available. Knee arthrography is a complex and safe procedure with very less discomfort for the patient; it has a central position in the evaluation of lesions of the knee. (orig.) [de

  15. Epidemiology of jumper's knee.

    Science.gov (United States)

    Ferretti, A

    1986-01-01

    Jumper's knee is a typical functional overload injury because it affects those athletes who submit their knee extensor mechanisms to intense and repeated stress, e.g. volleyball and basketball players, high and long jumpers. According to the classification of Perugia and colleagues, it is an insertional tendinopathy affecting, in order of frequency, the insertion of the patellar tendon into the patella (65% of cases), attachment of the quadriceps tendon to the patella (25%) and the attachment of the patellar tendon to the tibial tuberosity (10%). The frequent occurrence of this injury in athletes led to the study of factors that may contribute to its onset and aggravation. These factors are divided into extrinsic (i.e. kind of sport practised and training methods used) and intrinsic (i.e. connected with the somatic and morphological characteristics of the athletes). On the basis of our experience and after a review of the literature it appears, contrary to what has been repeatedly claimed in the past, the extrinsic factors are more important than the intrinsic in the aetiology of jumper's knee. The effect of traumatic incidents and use of elastic kneecap guards should also be considered negligible. The intrinsic causes of jumper's knee, can be sought in the mechanical properties of tendons (resistance, elasticity and extensibility) rather than in morphological or biomechanical abnormalities of the knee extensor mechanism.

  16. Relationship between lower limb muscle strength, self-reported pain and function, and frontal plane gait kinematics in knee osteoarthritis.

    Science.gov (United States)

    Park, Sang-Kyoon; Kobsar, Dylan; Ferber, Reed

    2016-10-01

    The relationship between muscle strength, gait biomechanics, and self-reported physical function and pain for patients with knee osteoarthritis is not well known. The objective of this study was to investigate these relationships in this population. Twenty-four patients with knee osteoarthritis and 24 healthy controls were recruited. Self-reported pain and function, lower-limb maximum isometric force, and frontal plane gait kinematics during treadmill walking were collected on all patients. Between-group differences were assessed for 1) muscle strength and 2) gait biomechanics. Linear regressions were computed within the knee osteoarthritis group to examine the effect of muscle strength on 1) self-reported pain and function, and 2) gait kinematics. Patients with knee osteoarthritis exhibited reduced hip external rotator, knee extensor, and ankle inversion muscle force output compared with healthy controls, as well as increased peak knee adduction angles (effect size=0.770; p=0.013). Hip abductor strength was a significant predictor of function, but not after controlling for covariates. Ankle inversion, hip abduction, and knee flexion strength were significant predictors of peak pelvic drop angle after controlling for covariates (34.4% unique variance explained). Patients with knee osteoarthritis exhibit deficits in muscle strength and while they play an important role in the self-reported function of patients with knee osteoarthritis, the effect of covariates such as sex, age, mass, and height was more important in this relationship. Similar relationships were observed from gait variables, except for peak pelvic drop, where hip, knee, and ankle strength remained important predictors of this variable after controlling for covariates. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Bottom-up estimation of joint moments during manual lifting using orientation sensors instead of position sensors

    NARCIS (Netherlands)

    Faber, G.S.; Kingma, I.; van Dieen, J.H.

    2010-01-01

    L5/S1, hip and knee moments during manual lifting tasks are, in a laboratory environment, frequently established by bottom-up inverse dynamics, using force plates to measure ground reaction forces (GRFs) and an optoelectronic system to measure segment positions and orientations. For field

  18. Adducts of rare earth tris-acetylacetonates with dimethyl sulfoxide

    International Nuclear Information System (INIS)

    Dzyubenko, N.G.; Kalenichenko, Yu.V.; Martynenko, L.I.

    1988-01-01

    Adducts of rare earth and yttrium (r.e.e., M) acetylacetonates with dimethyl sulfoxide (DMSO), MA 3 xnDMSO are synthesized. The acetylacetonates of light r.e.e. (M=La-Tb) are shown by different physico-chemical methods to form diadducts of the MA 3 x2DMSOxH 2 O composition, where A - -acetylacetonate-ion, and the acetyl-acetonates of heavy r.e.e. (M=Dy-Lu, Y)-monoadducts MA 3 xDMSO. The estimation of adduct thermal stability is carried out using the values of seeming activation energy of their thermal degradation. Monoadducts are shown to give volatile forms of rare earth acetylacetonates during heating in vacuum, and diadducts do not form volatile forms of acetylacetonates

  19. Bouncy knee in a semi-automatic knee lock prosthesis.

    Science.gov (United States)

    Fisher, L D; Lord, M

    1986-04-01

    The Bouncy Knee concept has previously proved of value when fitted to stabilised knee units of active amputees. The stance phase flex-extend action afforded by a Bouncy Knee increased the symmetry of gait and also gave better tolerance to slopes and uneven ground. A bouncy function has now been incorporated into a knee of the semi-automatic knee lock design in a pilot laboratory trial involving six patients. These less active patients did not show consistent changes in symmetry of gait, but demonstrated an improved ability to walk on slopes and increased their walking range. Subjective response was positive, as noted in the previous trials.

  20. Does knee awareness differ between different knee arthroplasty prostheses?

    DEFF Research Database (Denmark)

    Thomsen, Morten G; Latifi, Roshan; Kallemose, Thomas

    2016-01-01

    BACKGROUND: Low knee awareness after Total Knee Arthroplasty (TKA) has become the ultimate goal in trying to achieve a natural feeling knee that meet patient expectations. To accommodate this manufacturers of TKAs have developed new prosthetic designs that potentially could give patients a more...... natural feeling knee during activities. The purpose af this study was to compare the Forgotten Joint Score (FJS) and Oxford Knee Score (OKS) of patients treated with a previous generation standard Cruciate Retaining (CR) TKA to the scores obtained by patients treated with a newer generation CR TKA...

  1. DNA-adducts in fish exposed to alkylating carcinogens

    International Nuclear Information System (INIS)

    Giam, C.S.; Holliday, T.L.; Williams, J.L.; Bahnson, A.; Weller, R.; Hinton, D.E.

    1988-01-01

    There are limited studies on DNA-adduct formation following exposure of fish or fish cells to carcinogens. It will be essential to determine if procarcinogens and carcinogens form the same DNA-adducts in different liver cells and how these compare to those reported in mammalian livers. They are also interested in the influence of different alkylating agents on the type and quantity of DNA-adduct formation and repair in fish. While eggs or small fish are ideal for routine screening, large fish such as trout (Salmo gairdneri) is needed initially for the development of analytical procedures for the isolation, quantitation and identification of various adducts. Trout (Salmo gairdneri) weighing approximately 250 grams were acclimatized at 13 degree C before being given i.p. injection of diethylnitrosoamine (DEN). The exposure period varied, though most animals were sacrificed after 24 hours. Their livers were excised and DNA was isolated mainly according the procedure of Croy et al. The neutral thermal hydrolysate and the acid hydrolysate were analyzed by HPLC-Fluorescent detector for 7-ethylguanine and O 6 -ethylguanine, respectively. O 6 -ethylguanine was detected, 7-ethylguanine was not detected. Attempts are being made to improve the detection of the latter compound. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) was used to establish nanogram quantities of the ethylated bases. Laser desorption FT-IC-MS is particularly useful for characterizing thermally-labile and involatile nucleosides or nucleotides. Excretion of DEN was rapid and high. Exposure of trout (and other fish) to various ethylating agents will be discussed

  2. Protein tyrosine adduct in humans self-poisoned by chlorpyrifos

    International Nuclear Information System (INIS)

    Li, Bin; Eyer, Peter; Eddleston, Michael; Jiang, Wei; Schopfer, Lawrence M.; Lockridge, Oksana

    2013-01-01

    Studies of human cases of self-inflicted poisoning suggest that chlorpyrifos oxon reacts not only with acetylcholinesterase and butyrylcholinesterase but also with other blood proteins. A favored candidate is albumin because in vitro and animal studies have identified tyrosine 411 of albumin as a site covalently modified by organophosphorus poisons. Our goal was to test this proposal in humans by determining whether plasma from humans poisoned by chlorpyrifos has adducts on tyrosine. Plasma samples from 5 self-poisoned humans were drawn at various time intervals after ingestion of chlorpyrifos for a total of 34 samples. All 34 samples were analyzed for plasma levels of chlorpyrifos and chlorpyrifos oxon (CPO) as a function of time post-ingestion. Eleven samples were analyzed for the presence of diethoxyphosphorylated tyrosine by mass spectrometry. Six samples yielded diethoxyphosphorylated tyrosine in pronase digests. Blood collected as late as 5 days after chlorpyrifos ingestion was positive for CPO-tyrosine, consistent with the 20-day half-life of albumin. High plasma CPO levels did not predict detectable levels of CPO-tyrosine. CPO-tyrosine was identified in pralidoxime treated patients as well as in patients not treated with pralidoxime, indicating that pralidoxime does not reverse CPO binding to tyrosine in humans. Plasma butyrylcholinesterase was a more sensitive biomarker of exposure than adducts on tyrosine. In conclusion, chlorpyrifos oxon makes a stable covalent adduct on the tyrosine residue of blood proteins in humans who ingested chlorpyrifos. - Highlights: • Chlorpyrifos-poisoned patients have adducts on protein tyrosine. • Diethoxyphosphate-tyrosine does not lose an alkyl group. • Proteins in addition to AChE and BChE are modified by organophosphates

  3. Protein tyrosine adduct in humans self-poisoned by chlorpyrifos

    Energy Technology Data Exchange (ETDEWEB)

    Li, Bin, E-mail: binli@unmc.edu [Eppley Institute, University of Nebraska Medical Center, Omaha, NE 68198-5950 (United States); Eyer, Peter, E-mail: peter.eyer@lrz.uni-muenchen.de [Walther-Straub-Institut Für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, 80336 München (Germany); Eddleston, Michael, E-mail: M.Eddleston@ed.ac.uk [Clinical Pharmacology Unit, University of Edinburgh, Edinburgh (United Kingdom); Jiang, Wei, E-mail: wjiang@unmc.edu [Eppley Institute, University of Nebraska Medical Center, Omaha, NE 68198-5950 (United States); Schopfer, Lawrence M., E-mail: lmschopf@unmc.edu [Eppley Institute, University of Nebraska Medical Center, Omaha, NE 68198-5950 (United States); Lockridge, Oksana, E-mail: olockrid@unmc.edu [Eppley Institute, University of Nebraska Medical Center, Omaha, NE 68198-5950 (United States)

    2013-06-15

    Studies of human cases of self-inflicted poisoning suggest that chlorpyrifos oxon reacts not only with acetylcholinesterase and butyrylcholinesterase but also with other blood proteins. A favored candidate is albumin because in vitro and animal studies have identified tyrosine 411 of albumin as a site covalently modified by organophosphorus poisons. Our goal was to test this proposal in humans by determining whether plasma from humans poisoned by chlorpyrifos has adducts on tyrosine. Plasma samples from 5 self-poisoned humans were drawn at various time intervals after ingestion of chlorpyrifos for a total of 34 samples. All 34 samples were analyzed for plasma levels of chlorpyrifos and chlorpyrifos oxon (CPO) as a function of time post-ingestion. Eleven samples were analyzed for the presence of diethoxyphosphorylated tyrosine by mass spectrometry. Six samples yielded diethoxyphosphorylated tyrosine in pronase digests. Blood collected as late as 5 days after chlorpyrifos ingestion was positive for CPO-tyrosine, consistent with the 20-day half-life of albumin. High plasma CPO levels did not predict detectable levels of CPO-tyrosine. CPO-tyrosine was identified in pralidoxime treated patients as well as in patients not treated with pralidoxime, indicating that pralidoxime does not reverse CPO binding to tyrosine in humans. Plasma butyrylcholinesterase was a more sensitive biomarker of exposure than adducts on tyrosine. In conclusion, chlorpyrifos oxon makes a stable covalent adduct on the tyrosine residue of blood proteins in humans who ingested chlorpyrifos. - Highlights: • Chlorpyrifos-poisoned patients have adducts on protein tyrosine. • Diethoxyphosphate-tyrosine does not lose an alkyl group. • Proteins in addition to AChE and BChE are modified by organophosphates.

  4. PHOSPHATO AND PHOSPHONATO ADDUCTS: SYNTHESIS AND SPECTROSCOPIC STUDY

    Directory of Open Access Journals (Sweden)

    Mouhamadou Birame Diop

    2014-05-01

    Full Text Available Two new adducts have been synthesized and studied by infrared and NMR spectroscopy. The suggested structures are discrete or of infinite chain type with a phosphate behaving as a bidentate ligand, a phosphonate acting as a monodentate ligand, the environments around the tin centre being tetrahedral or trigonal bipyramidal. In all the studied compounds, supramolecular architectures are obtained when hydrogen bonds are considered.

  5. Protein modification by acrolein: Formation and stability of cysteine adducts

    OpenAIRE

    Cai, Jian; Bhatnagar, Aruni; Pierce, William M.

    2009-01-01

    The toxicity of the ubiquitous pollutant and endogenous metabolite, acrolein, is due in part to covalent protein modifications. Acrolein reacts readily with protein nucleophiles via Michael addition and Schiff base formation. Potential acrolein targets in protein include the nucleophilic side chains of cysteine, histidine, and lysine residues as well as the free amino terminus of proteins. Although cysteine is the most acrolein-reactive residue, cysteine-acrolein adducts are difficult to iden...

  6. Exposure of bus and taxi drivers to urban air pollutants as measured by DNA and protein adducts

    DEFF Research Database (Denmark)

    Hemminki, K.; Zhang, L.F.; Krüger, J.

    1994-01-01

    Urinary 1-hydroxypyrene, lymphocyte DNA adducts, serum protein-bound PAH and hemoglobin-bound alkene adducts were analysed from 4 groups of non-smoking men: urban and suburban bus drivers, taxi drivers and suburban controls. The only differences between the groups were in DNA adducts between...... suburban bus drivers and controls, and in DNA adduct and plasma protein PAH-adducts between taxi drivers and controls....

  7. The Effect of Work Boots on Knee Mechanics and the Center of Pressure at the Knee During Static Kneeling.

    Science.gov (United States)

    Tennant, Liana; Kingston, David; Chong, Helen; Acker, Stacey

    2015-10-01

    Occupational kneeling is associated with an increased risk for the development of knee osteoarthritis. Previous work studying occupational kneeling has neglected to account for the fact that in many industrial settings, workers are required to wear steel-toe work boots. Thus, the purpose of this study was to evaluate the effect of work boot wear on the center of pressure location of the ground reaction force, knee joint angle, and magnitude of the ground reaction force in a kneeling posture. Fifteen healthy males were fit with 3D motion capture markers and knelt statically over a force plate embedded in the floor. Using the tibial tuberosity as the point of reference, the center of pressure in shod condition was shifted significantly medially (on average 0.009 m [P = .005]) compared with the barefoot condition. The knee was significantly less internally rotated (shod: -12.5° vs. barefoot: -17.4° [P = .009]) and the anterior/posterior shear force was significantly greater in the shod condition (shod: 6.0% body weight vs. barefoot: 1.5% body weight [P = .002]). Therefore, wearing work boots alters the kneeling posture compared with barefoot kneeling, potentially loading different surfaces of the knee, as well as altering knee joint moments.

  8. Diagnosis and dosimetry of exposure to sulfur mustard: Development of a standard operating procedure for hemoglobin adducts: Exploratory research on albumin and keratin adducts

    NARCIS (Netherlands)

    Noort, D.; Fidder, A.; Jong, L.P.A. de; Schans, G.P. van der; Benschop, H.P.

    2000-01-01

    A standard operating procedure (SOP) for determination of the sulfur mustard adduct to the N-terminal valine in hemoglobin was developed. By using this SOP, it was found that the Nterminal valine adduct in globin of hairless guinea pigs and marmosets which had been exposed to sulfur mustard (0.5

  9. Effect of turmeric and curcumin on BP-DNA adducts.

    Science.gov (United States)

    Mukundan, M A; Chacko, M C; Annapurna, V V; Krishnaswamy, K

    1993-03-01

    Many human cancers that are widely prevalent today can be prevented through modifications in life-styles, of which diet appears to be an important agent. Several dietary constituents modulate the process of carcinogenesis and prevent genotoxicity. Many plant constituents including turmeric appear to be potent antimutagens and antioxidants. Therefore the modulatory effects of turmeric and curcumin on the levels of benzo[a]pyrene induced DNA adducts in the livers of rats were studied by the newly developed 32P-postlabelling assay method. Turmeric when fed at 0.1, 0.5 and 3% and the active principle of turmeric (curcumin) when fed at a level of 0.03% in the diet for 4 weeks significantly reduced the level of BP-DNA adducts including the major adduct dG-N2-BP, formed within 24 h in response to a single i.p. injection of benzo[a]pyrene. The significance of these effects in terms of the potential anticarcinogenic effects of turmeric is discussed. Further, these results strengthen the various other biological effects of turmeric which have direct relevance to anticarcinogenesis and chemoprevention.

  10. Protein tyrosine adduct in humans self-poisoned by chlorpyrifos

    Science.gov (United States)

    Li, Bin; Eyer, Peter; Eddleston, Michael; Jiang, Wei; Schopfer, Lawrence M.; Lockridge, Oksana

    2013-01-01

    Studies of human cases of self-inflicted poisoning suggest that chlorpyrifos oxon reacts not only with acetylcholinesterase and butyrylcholinesterase but also with other blood proteins. A favored candidate is albumin because in vitro and animal studies have identified tyrosine 411 of albumin as a site covalently modified by organophosphorus poisons. Our goal was to test this proposal in humans by determining whether plasma from humans poisoned by chlorpyrifos has adducts on tyrosine. Plasma samples from 5 self-poisoned humans were drawn at various time intervals after ingestion of chlorpyrifos for a total of 34 samples. All 34 samples were analyzed for plasma levels of chlorpyrifos and chlorpyrifos oxon (CPO) as a function of time post-ingestion. Eleven samples were analyzed for the presence of diethoxyphosphorylated tyrosine by mass spectrometry. Six samples yielded diethoxyphosphorylated tyrosine in pronase digests. Blood collected as late as 5 days after chlorpyrifos ingestion was positive for CPO-tyrosine, consistent with the 20-day half-life of albumin. High plasma CPO levels did not predict detectable levels of CPO-tyrosine. CPO-tyrosine was identified in pralidoxime treated patients as well as in patients not treated with pralidoxime, indicating that pralidoxime does not reverse CPO binding to tyrosine in humans. Plasma butyrylcholinesterase was a more sensitive biomarker of exposure than adducts on tyrosine. In conclusion, chlorpyrifos oxon makes a stable covalent adduct on the tyrosine residue of blood proteins in humans who ingested chlorpyrifos. PMID:23566956

  11. Ground reaction forces and knee mechanics in the weight acceptance phase of a dance leap take-off and landing.

    Science.gov (United States)

    Kulig, Kornelia; Fietzer, Abbigail L; Popovich, John M

    2011-01-01

    Aesthetic constraints allow dancers fewer technique modifications than other athletes to negotiate the demands of leaping. We examined vertical ground reaction force and knee mechanics during a saut de chat performed by healthy dancers. It was hypothesized that vertical ground reaction force during landing would exceed that of take-off, resulting in greater knee extensor moments and greater knee angular stiffness. Twelve dancers (six males, six females; age 18.9 ± 1.2 years, mass 59.2 ± 9.5 kg, height 1.68 ± 0.08 m, dance training 8.9 ± 5.1 years) with no history of low back pain or lower extremity pathology participated in the study. Saut de chat data were captured using an eight-camera Vicon system and AMTI force platforms. Peak ground reaction force was 26% greater during the landing phase, but did not result in increased peak knee extensor moments. Taking into account the 67% greater knee angular displacement during landing, this resulted in less knee angular stiffness during landing. In conclusion, landing was accomplished with less knee angular stiffness despite the greater peak ground reaction force. A link between decreased joint angular stiffness and increased soft tissue injury risk has been proposed elsewhere; therefore, landing from a saut de chat may be more injurious to the knee soft tissue than take-off.

  12. The relationship between leg preference and knee mechanics during sidestepping in collegiate female footballers.

    Science.gov (United States)

    Brown, Scott R; Wang, Henry; Dickin, D Clark; Weiss, Kaitlyn J

    2014-11-01

    This study examined the relationship between leg preference and knee mechanics in females during sidestepping. Three-dimensional data were recorded on 16 female collegiate footballers during a planned 45° sidestep manoeuvre with their preferred and non-preferred kicking leg. Knee kinematics and kinetics during initial contact, weight acceptance, peak push-off, and final push-off phases of sidestepping were analysed in both legs. The preferred leg showed trivial to small increases (ES = 0.19-0.36) in knee flexion angle at initial contact, weight acceptance, and peak push-off, and small increases (ES = 0.21-0.34) in peak power production and peak knee extension velocity. The non-preferred leg showed a trivial increase (ES = 0.10) in knee abduction angle during weight acceptance; small to moderate increases (ES = 0.22-0.64) in knee internal rotation angle at weight acceptance, peak push-off, and final push-off; a small increase (ES = 0.22) in knee abductor moment; and trivial increases (ES = 0.09-0.14) in peak power absorption and peak knee flexion velocity. The results of this study show that differences do exist between the preferred and non-preferred leg in females. The findings of this study will increase the knowledge base of anterior cruciate ligament injury in females and can aid in the design of more appropriate neuromuscular, plyometric, and strength training protocols for injury prevention.

  13. Electric moments in molecule interferometry

    International Nuclear Information System (INIS)

    Eibenberger, Sandra; Gerlich, Stefan; Arndt, Markus; Tuexen, Jens; Mayor, Marcel

    2011-01-01

    We investigate the influence of different electric moments on the shift and dephasing of molecules in a matter wave interferometer. Firstly, we provide a quantitative comparison of two molecules that are non-polar yet polarizable in their thermal ground state and that differ in their stiffness and response to thermal excitations. While C 25 H 20 is rather rigid, its larger derivative C 49 H 16 F 52 is additionally equipped with floppy side chains and vibrationally activated dipole moment variations. Secondly, we elucidate the role of a permanent electric dipole momentby contrasting the quantum interference pattern of a (nearly) non-polar and a polar porphyrin derivative. We find that a high molecular polarizability and even sizeable dipole moment fluctuations are still well compatible with high-contrast quantum interference fringes. The presence of permanent electric dipole moments, however, can lead to a dephasing and rapid degradation of the quantum fringe pattern already at moderate electric fields. This finding is of high relevance for coherence experiments with large organic molecules, which are generally equipped with strong electric moments.

  14. Including the Copenhagen Adduction Exercise in the FIFA 11+ Provides Missing Eccentric Hip Adduction Strength Effect in Male Soccer Players: A Randomized Controlled Trial.

    Science.gov (United States)

    Harøy, Joar; Thorborg, Kristian; Serner, Andreas; Bjørkheim, André; Rolstad, Linn E; Hölmich, Per; Bahr, Roald; Andersen, Thor Einar

    2017-11-01

    The FIFA 11+ was developed as a complete warm-up program to prevent injuries in soccer players. Although reduced hip adduction strength is associated with groin injuries, none of the exercises included in the FIFA 11+ seem to specifically target hip adduction strength. To investigate the effect on eccentric hip adduction strength of the FIFA 11+ warm-up program with or without the Copenhagen adduction exercise. Randomized controlled trial; Level of evidence, 1. We recruited 45 eligible players from 2 U19 elite male soccer teams. Players were randomized into 2 groups; 1 group carried out the standard FIFA 11+ program, while the other carried out the FIFA 11+ but replaced the Nordic hamstring exercise with the Copenhagen adduction exercise. Both groups performed the intervention 3 times weekly for 8 weeks. Players completed eccentric strength and sprint testing before and after the intervention. Per-protocol analyses were performed, and 12 players were excluded due to low compliance (<67% of sessions completed). The main outcome was eccentric hip adduction strength (N·m/kg). Between-group analyses revealed a significantly greater increase in eccentric hip adduction strength of 0.29 Nm/kg (8.9%; P = .01) in favor of the group performing the Copenhagen adduction exercise, whereas no within-group change was noted in the group that used the standard FIFA 11+ program (-0.02 N·m/kg [-0.7%]; P = .69). Including the Copenhagen adduction exercise in the FIFA 11+ program increases eccentric hip adduction strength, while the standard FIFA 11+ program does not. Registration: Registration: ISRCTN13731446 (International Standard Randomised Controlled Trial Number registry).

  15. Heat generated by knee prostheses.

    Science.gov (United States)

    Pritchett, James W

    2006-01-01

    Temperature sensors were placed in 50 knees in 25 patients who had one or both joints replaced. Temperature recordings were made before walking, after walking, and after cycling. The heat generated in healthy, arthritic, and replaced knees was measured. The knee replacements were done using eight different prostheses. A rotating hinge knee prosthesis generated a temperature increase of 7 degrees C in 20 minutes and 9 degrees C in 40 minutes. An unconstrained ceramic femoral prosthesis articulating with a polyethylene tibial prosthesis generated a temperature increase of 4 degrees C compared with a healthy resting knee. The other designs using a cobalt-chrome alloy and high-density polyethylene had temperature increases of 5 degrees-7 degrees C with exercise. Frictional heat generated in a prosthetic knee is not immediately dissipated and may result in wear, creep, and other degenerative processes in the high-density polyethylene. Extended periods of elevated temperature in joints may inhibit cell growth and perhaps contribute to adverse performance via bone resorption or component loosening. Prosthetic knees generate more heat with activity than healthy or arthritic knees. More-constrained knee prostheses generate more heat than less-constrained prostheses. A knee with a ceramic femoral component generates less heat than a knee with the same design using a cobalt-chromium alloy.

  16. Arthroscopic surgery for degenerative knee

    DEFF Research Database (Denmark)

    Thorlund, J B; Juhl, C B; Roos, E M

    2015-01-01

    OBJECTIVE: To determine benefits and harms of arthroscopic knee surgery involving partial meniscectomy, debridement, or both for middle aged or older patients with knee pain and degenerative knee disease. DESIGN: Systematic review and meta-analysis. MAIN OUTCOME MEASURES: Pain and physical function....... RESULTS: The search identified nine trials assessing the benefits of knee arthroscopic surgery in middle aged and older patients with knee pain and degenerative knee disease. The main analysis, combining the primary endpoints of the individual trials from three to 24 months postoperatively, showed a small...... included symptomatic deep venous thrombosis (4.13 (95% confidence interval 1.78 to 9.60) events per 1000 procedures), pulmonary embolism, infection, and death. CONCLUSIONS: The small inconsequential benefit seen from interventions that include arthroscopy for the degenerative knee is limited in time...

  17. Anterior approach for knee arthrography

    International Nuclear Information System (INIS)

    Zurlo, J.V.; Towers, J.D.; Golla, S.

    2001-01-01

    Objective. To develop a new method of magnetic resonance arthrography (MRA) of the knee using an anterior approach analogous to the portals used for knee arthroscopy.Design. An anterior approach to the knee joint was devised mimicking anterior portals used for knee arthroscopy. Seven patients scheduled for routine knee MRA were placed in a decubitus position and under fluoroscopic guidance a needle was advanced from a position adjacent to the patellar tendon into the knee joint. After confirmation of the needle tip location, a dilute gadolinium solution was injected.Results and conclusion. All the arthrograms were technically successful. The anterior approach to knee MRA has greater technical ease than the traditional approach with little patient discomfort. (orig.)

  18. Stochastic Generalized Method of Moments

    KAUST Repository

    Yin, Guosheng; Ma, Yanyuan; Liang, Faming; Yuan, Ying

    2011-01-01

    The generalized method of moments (GMM) is a very popular estimation and inference procedure based on moment conditions. When likelihood-based methods are difficult to implement, one can often derive various moment conditions and construct the GMM objective function. However, minimization of the objective function in the GMM may be challenging, especially over a large parameter space. Due to the special structure of the GMM, we propose a new sampling-based algorithm, the stochastic GMM sampler, which replaces the multivariate minimization problem by a series of conditional sampling procedures. We develop the theoretical properties of the proposed iterative Monte Carlo method, and demonstrate its superior performance over other GMM estimation procedures in simulation studies. As an illustration, we apply the stochastic GMM sampler to a Medfly life longevity study. Supplemental materials for the article are available online. © 2011 American Statistical Association.

  19. Stochastic Generalized Method of Moments

    KAUST Repository

    Yin, Guosheng

    2011-08-16

    The generalized method of moments (GMM) is a very popular estimation and inference procedure based on moment conditions. When likelihood-based methods are difficult to implement, one can often derive various moment conditions and construct the GMM objective function. However, minimization of the objective function in the GMM may be challenging, especially over a large parameter space. Due to the special structure of the GMM, we propose a new sampling-based algorithm, the stochastic GMM sampler, which replaces the multivariate minimization problem by a series of conditional sampling procedures. We develop the theoretical properties of the proposed iterative Monte Carlo method, and demonstrate its superior performance over other GMM estimation procedures in simulation studies. As an illustration, we apply the stochastic GMM sampler to a Medfly life longevity study. Supplemental materials for the article are available online. © 2011 American Statistical Association.

  20. Knee osteoarthritis in traumatic knee symptoms in general practice: 6-year cohort study

    NARCIS (Netherlands)

    M. Kastelein (Marlous); P.A.J. Luijsterburg (Pim); I.M. Koster (Ingrid); J.A.N. Verhaar (Jan); D. Vroegindeweij (Dammis); S.M. Bierma-Zeinstra (Sita); E.H.G. Oei (Edwin)

    2016-01-01

    textabstractAim: To identify degenerative knee abnormalities using MRI and radiography 6 years after knee trauma, their relation with persistent knee symptoms and baseline prognostic factors. Methods: Adults (18–65 years) with incident traumatic knee symptoms visiting their

  1. Knees Lifted High

    Centers for Disease Control (CDC) Podcasts

    The Eagle Books are a series of four books that are brought to life by wise animal characters - Mr. Eagle, Miss Rabbit, and Coyote - who engage Rain That Dances and his young friends in the joy of physical activity, eating healthy foods, and learning from their elders about health and diabetes prevention. Knees Lifted High gives children fun ideas for active outdoor play.

  2. Knee injuries in football

    African Journals Online (AJOL)

    swimming and basketball.1 In 2001 it was reported to have injury rates of 1 000 times ... knee injury in football are the age of the player, a previous injury and the ligamentous .... football is possible, although the success rates may vary from ...

  3. Unicompartmental knee arthroplasty

    NARCIS (Netherlands)

    Kort, Nanne Pieter

    2007-01-01

    This thesis concerns technical aspects of unicompartmental knee arthroplasty. Recent years have witnessed a resurgence of interest in unicompartmental arthroplasty, particularly with the introduction of the minimally invasive technique. In the light of the excellent long-term results of the total

  4. Method of moments in electromagnetics

    CERN Document Server

    Gibson, Walton C

    2007-01-01

    Responding to the need for a clear, up-to-date introduction to the field, The Method of Moments in Electromagnetics explores surface integral equations in electromagnetics and presents their numerical solution using the method of moments (MOM) technique. It provides the numerical implementation aspects at a nuts-and-bolts level while discussing integral equations and electromagnetic theory at a higher level. The author covers a range of topics in this area, from the initial underpinnings of the MOM to its current applications. He first reviews the frequency-domain electromagnetic theory and t

  5. Neutron star moments of inertia

    Science.gov (United States)

    Ravenhall, D. G.; Pethick, C. J.

    1994-01-01

    An approximation for the moment of inertia of a neutron star in terms of only its mass and radius is presented, and insight into it is obtained by examining the behavior of the relativistic structural equations. The approximation is accurate to approximately 10% for a variety of nuclear equations of state, for all except very low mass stars. It is combined with information about the neutron-star crust to obtain a simple expression (again in terms only of mass and radius) for the fractional moment of inertia of the crust.

  6. Knee kinematics and kinetics in former soccer players with a 16-year-old ACL injury – the effects of twelve weeks of knee-specific training

    Directory of Open Access Journals (Sweden)

    Holmström Eva

    2007-04-01

    Full Text Available Abstract Background Training of neuromuscular control has become increasingly important and plays a major role in rehabilitation of subjects with an injury to the anterior cruciate ligament (ACL. Little is known, however, of the influence of this training on knee stiffness during loading. Increased knee stiffness occurs as a loading strategy of ACL-injured subjects and is associated with increased joint contact forces. Increased or altered joint loads contribute to the development of osteoarthritis. The aim of the study was to determine if knee stiffness, defined by changes in knee kinetics and kinematics of gait, step activity and cross-over hop could be reduced through a knee-specific 12-week training programme. Methods A 3-dimensional motion analysis system (VICON and a force plate (AMTI were used to calculate knee kinetics and kinematics before and after 12 weeks of knee-specific training in 12 males recruited from a cohort with ACL injury 16 years earlier. Twelve uninjured males matched for age, sex, BMI and activity level served as a reference group. Self-reported patient-relevant data were obtained by the KOOS questionnaire. Results There were no significant changes in knee stiffness during gait and step activity after training. For the cross-over hop, increased peak knee flexion during landing (from 44 to 48 degrees, p = 0.031 and increased internal knee extensor moment (1.28 to 1.55 Nm/kg, p = 0.017 were seen after training, indicating reduced knee stiffness. The KOOS sport and recreation score improved from 70 to 77 (p = 0.005 and was significantly correlated with the changes in knee flexion during landing for the cross-over hop (r = 0.6, p = 0.039. Conclusion Knee-specific training improved lower extremity kinetics and kinematics, indicating reduced knee stiffness during demanding hop activity. Self-reported sport and recreational function correlated positively with the biomechanical changes supporting a clinical importance of the

  7. Zinc acetylacetonate hydrate adducted with nitrogen donor ligands: Synthesis, spectroscopic characterization, and thermal analysis

    Science.gov (United States)

    Brahma, Sanjaya; Shivashankar, S. A.

    2015-12-01

    We report synthesis, spectroscopic characterization, and thermal analysis of zinc acetylacetonate complex adducted by nitrogen donor ligands, such as pyridine, bipyridine, and phenanthroline. The pyridine adducted complex crystallizes to monoclinic crystal structure, whereas other two adducted complexes have orthorhombic structure. Addition of nitrogen donor ligands enhances the thermal property of these complexes as that with parent metal-organic complex. Zinc acetylacetonate adducted with pyridine shows much higher volatility (106 °C), decomposition temperature (202 °C) as that with zinc acetylacetonate (136 °C, 220 °C), and other adducted complexes. All the adducted complexes are thermally stable, highly volatile and are considered to be suitable precursors for metal organic chemical vapor deposition. The formation of these complexes is confirmed by powder X-ray diffraction, Fourier transform infrared spectroscopy, mass spectroscopy, and elemental analysis. The complexes are widely used as starting precursor materials for the synthesis of ZnO nanostructures by microwave irradiation assisted coating process.

  8. Decay kinetics of nicotine/NNK-DNA adducts in vivo studied by accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Sun, H.F.; He, L.; Liu, Y.F.; Liu, K.X.; Lu, X.Y.; Wang, J.J.; Ma, H.J.; Li, K.

    2000-01-01

    The decay kinetics of nicotine-DNA adducts and NNK-DNA adducts in mice liver after single dosing was studied by accelerator mass spectrometry (AMS). The decay is characterized by a two-stage process. The half-lives of nicotine-DNA adducts are 1.3 d (4-24 h) and 7.0 d (1-21 d), while for NNK-DNA adducts are 0.7 d (4-24 h) and 18.0 d (1-21 d). The relatively faster decay of nicotine-DNA adducts suggests that the genotoxicity of nicotine is weaker than that of NNK. The in vitro study shows that the metabolization of nicotine is necessary for the final formation of nicotine-DNA adducts, and nicotine Δ1'(5') iminium ion is a probable metabolite species that binds to DNA molecule covalently

  9. Fast repair of oxidizing OH adducts of DNA by hydroxycinnamic acid derivatives. A pulse radiolytic study

    International Nuclear Information System (INIS)

    Yue Jiang; Lin Weizhen; Yao Side; Lin Nianyun; Zhu Dayuan

    1999-01-01

    Using pulse radiolytic techniques, it has been demonstrated that the interactions of oxidizing OH adducts of DNA (ssDNA and dsDNA), polyA and polyG with hydroxycinnamic acid derivatives proceed via an electron transfer process (k=5-30x10 8 dm 3 mol -1 s -1 ). In addition, the rates for fast repair of OH adducts of dAMP, polyA and DNA (ssDNA and dsDNA) are slower than the corresponding rates for the rest OH adducts of DNA constituents. The slower rates for repair of oxidizing OH adducts of dAMP may be the rate determining step during the interaction of hydroxycinnamic acid derivatives with OH adducts of DNA containing the varieties of OH adducts of DNA constituents

  10. /sup 32/P-postlabelling analysis of aromatic DNA adducts in human oral mucosal cells

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, B.P.; Stich, H.F.

    1986-07-01

    Exfoliated mucosal cells were collected from the oral cavity of three groups at high risk for oral cancer: Indian betel nut chewers, Filipino inverted smokers (burning end of cigar in mouth) and Indian Khaini tobacco chewers. DNA was extracted from these samples, as well as from samples of exfoliated cells of Canadian non-smoking controls. DNA was analyzed for the presence of aromatic DNA adducts using /sup 32/P-postlabelling analysis. Five chromatographically distinct adducts were found in samples from both the high risk groups and the nonsmoking controls. Individual adducts were detectable in approximately 30-95% of samples, depending on the adduct and population group. Estimated levels of specific adducts ranged from non-detectable (prevalence relative to normal nucleotides less than 1 X 10(-9)) to occasionally greater than 1 X 10(-7). No adducts were found in high risk groups which did not also appear in control subjects.

  11. Electromyographic preactivation pattern of the gluteus medius during weight-bearing functional tasks in women with and without anterior knee pain

    OpenAIRE

    Nakagawa,Theresa H.; Muniz,Thiago B.; Baldon,Rodrigo M.; Maciel,Carlos D.; Amorim,César F.; Serrão,Fábio V.

    2011-01-01

    BACKGROUND: Proximal factors have been proposed to influence the biomechanics of the patellofemoral joint. A delayed or diminished gluteus medius (GM) activation, before the foot contact on the ground during functional activities could lead to excessive femur adduction and internal rotation and be associated with anterior knee pain (AKP). There are few studies on this topic and the results were inconclusive, therefore, it is necessary to investigate the GM preactivation pattern during functio...

  12. Bulky DNA adducts in white blood cells: a pooled analysis of 3,600 subjects

    DEFF Research Database (Denmark)

    Ricceri, Fulvio; Godschalk, Roger W; Peluso, Marco

    2010-01-01

    Bulky DNA adducts are markers of exposure to genotoxic aromatic compounds, which reflect the ability of an individual to metabolically activate carcinogens and to repair DNA damage. Polycyclic aromatic hydrocarbons (PAHs) represent a major class of carcinogens that are capable of forming such add...... such adducts. Factors that have been reported to be related to DNA adduct levels include smoking, diet, body mass index (BMI), genetic polymorphisms, the season of collection of biologic material, and air pollutants....

  13. Detection and quantification of 4-ABP adducts in DNA from bladder cancer patients.

    Science.gov (United States)

    Zayas, Beatriz; Stillwell, Sara W; Wishnok, John S; Trudel, Laura J; Skipper, Paul; Yu, Mimi C; Tannenbaum, Steven R; Wogan, Gerald N

    2007-02-01

    We analyzed bladder DNA from 27 cancer patients for dG-C8-4-aminobiphenyl (dG-C8-ABP) adducts using the liquid chromatography tandem mass spectrometry method with a 700 attomol (1 adduct in 10(9) bases) detection limit. Hemoglobin (Hb) 4-aminobiphenyl (4-ABP) adduct levels were measured by gas chromatography-mass spectrometry. After isolation of dG-C8-ABP by immunoaffinity chromatography and further purification, deuterated (d9) dG-C8-ABP (MW=443 Da) was added to each sample. Structural evidence and adduct quantification were determined by selected reaction monitoring, based on the expected adduct ion [M+H+]+1, at m/z 435 with fragmentation to the product ion at m/z 319, and monitoring of the transition for the internal standard, m/z 444-->328. The method was validated by analysis of DNA (100 microg each) from calf thymus; livers from ABP-treated and untreated rats; human placentas; and TK6 lymphoblastoid cells. Adduct was detected at femtomol levels in DNA from livers of ABP-treated rats and calf thymus, but not in other controls. The method was applied to 41 DNA samples (200 microg each) from 27 human bladders; 28 from tumor and 14 from surrounding non-tumor tissue. Of 27 tissues analyzed, 44% (12) contained 5-80 dG-C8-ABP adducts per 10(9) bases; only 1 out of 27 (4%) contained adduct in both tumor and surrounding tissues. The Hb adduct was detected in samples from all patients, at levels of 12-1960 pg per gram Hb. There was no correlation between levels of DNA and Hb adducts. The presence of DNA adducts in 44% of the subjects and high levels of Hb adducts in these non-smokers indicate environmental sources of exposure to 4-ABP.

  14. 21 CFR 888.3570 - Knee joint femoral (hemi-knee) metallic uncemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint femoral (hemi-knee) metallic uncemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3570 Knee joint femoral (hemi-knee) metallic uncemented prosthesis. (a) Identification. A knee joint femoral (hemi-knee...

  15. 21 CFR 888.3590 - Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint tibial (hemi-knee) metallic resurfacing... Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis is a device intended to be implanted...

  16. 21 CFR 888.3580 - Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint patellar (hemi-knee) metallic... § 888.3580 Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis is a device made of...

  17. Mass-spectrometric study of volatile uranyl β-diketonates and their adducts

    International Nuclear Information System (INIS)

    Adamov, V.M.; Belyaev, B.N.; Berezinskij, S.O.; Sidorenko, G.V.; Suglobov, D.N.

    1985-01-01

    The mass spectra of a number of uranyl β-diketonates containing methyl, trifluoromethyl and tert-butyl substituents in β-diketonate anion, and their adducts are measured. The form of the unsolvated β-diketonates and their adducts in gas phase is studied. The ways of fragmentation of uranyl β-diketonates and their adducts are investigated. The data concerning the thermal and chemical side reactions proceeding with uranyl β-diketonates and their addicts in an ion source are obtained. The mass spectra of the samples of neptunyl and plutonyl β-diketonate adducts synthesized for the first time are measured

  18. Temporal and spatial features of the formation of DNA adducts in sulfur mustard-exposed skin

    Energy Technology Data Exchange (ETDEWEB)

    Batal, Mohamed [Laboratoire «Lésions des Acides Nucléiques», Université Joseph Fourier – Grenoble 1, CEA/Institut Nanoscience et Cryogénie/SCIB, UMR-E3, Grenoble (France); Département de Toxicologie et Risques Chimiques, Unité de Brûlure Chimique, Institut de Recherche Biomédicale des Armées, Antenne de La Tronche (France); Boudry, Isabelle; Mouret, Stéphane; Wartelle, Julien; Emorine, Sandy; Bertoni, Marine [Département de Toxicologie et Risques Chimiques, Unité de Brûlure Chimique, Institut de Recherche Biomédicale des Armées, Antenne de La Tronche (France); Bérard, Izabel [Laboratoire «Lésions des Acides Nucléiques», Université Joseph Fourier – Grenoble 1, CEA/Institut Nanoscience et Cryogénie/SCIB, UMR-E3, Grenoble (France); Cléry-Barraud, Cécile [Département de Toxicologie et Risques Chimiques, Unité de Brûlure Chimique, Institut de Recherche Biomédicale des Armées, Antenne de La Tronche (France); and others

    2013-12-15

    Sulfur mustard (SM) is a chemical warfare agent that targets skin where it induces large blisters. DNA alkylation is a critical step to explain SM-induced cutaneous symptoms. We determined the kinetics of formation of main SM–DNA adducts and compare it with the development of the SM-induced pathogenesis in skin. SKH-1 mice were exposed to 2, 6 and 60 mg/kg of SM and treated skin was biopsied between 6 h and 21 days. Formation of SM DNA adducts was dose-dependent with a maximum immediately after exposure. However, adducts were persistent and still detectable 21 days post-exposure. The time-dependent formation of DNA adducts was also found to be correlated with the appearance of apoptotic cells. This temporal correlation suggests that these two early events are responsible for the severity of the damage to the skin. Besides, SM–DNA adducts were also detected in areas located next to contaminated zone, thus suggesting that SM diffuses in skin. Altogether, this work provides for the first time a clear picture of SM-induced genotoxicity using DNA adducts as a marker. - Highlights: • Sulfur mustard adducts are formed in DNA after skin exposure. • DNA damage formation is an early event in the pathological process of skin burn. • The amount of SM–DNA adducts is maximal at the earliest time point investigated. • Adducts are still detected 3 weeks after exposure. • Sulfur mustard diffuses in skin especially when large doses are applied.

  19. Quiet Moment around the Campfire

    Centers for Disease Control (CDC) Podcasts

    2014-06-18

    Byron Breedlove reads his essay, "Quiet Moment around the Campfire," about the art of Frederic Remington and the transmission of pathogens as frontiers expand.  Created: 6/18/2014 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 6/19/2014.

  20. Particle electric dipole-moments

    Energy Technology Data Exchange (ETDEWEB)

    Pendlebury, J M [Sussex Univ., Brighton (United Kingdom)

    1997-04-01

    The incentive to detect particle electric dipole-moments, as a window on time-reversal violation, remains undiminished. Efforts to improve the measurements for the neutron, the electron and some nuclei are still making rapid progress as more powerful experimental methods are brought to bear. A new measurement for the neutron at ILL is presented. (author). 7 refs.

  1. Moment of Inertia by Differentiation

    Science.gov (United States)

    Rizcallah, Joseph A.

    2015-01-01

    The calculation of the moment of inertia of an extended body, as presented in standard introductory-level textbooks, involves the evaluation of a definite integral--an operation often not fully mastered by beginners, let alone the conceptual difficulties it presents, even to the advanced student, in understanding and setting up the integral in the…

  2. Unteachable Moments and Pedagogical Relationships

    Science.gov (United States)

    Wang, Hongyu

    2016-01-01

    This paper discusses how Julia Kristeva's theory can inform our understanding of unteachable moments. It proposes a pedagogical relationship that can contain breakdowns of meanings and work toward breakthroughs to new awareness, particularly related to social justice pedagogy in teacher education. First, one example from the author's own teaching…

  3. Moment Distributions of Phase Type

    DEFF Research Database (Denmark)

    Bladt, Mogens; Nielsen, Bo Friis

    2011-01-01

    Moment distributions of phase-type and matrix-exponential distributions are shown to remain within their respective classes. We provide a probabilistic phase-type representation for the former case and an alternative representation, with an analytically appealing form, for the latter. First order...

  4. Moment methods and Lanczos methods

    International Nuclear Information System (INIS)

    Whitehead, R.R.

    1980-01-01

    In contrast to many of the speakers at this conference I am less interested in average properties of nuclei than in detailed spectroscopy. I will try to show, however, that the two are very closely connected and that shell-model calculations may be used to give a great deal of information not normally associated with the shell-model. It has been demonstrated clearly to us that the level spacing fluctuations in nuclear spectra convey very little physical information. This is true when the fluctuations are averaged over the entire spectrum but not if one's interest is in the lowest few states, whose spacings are relatively large. If one wishes to calculate a ground state (say) accurately, that is with an error much smaller than the excitation energy of the first excited state, very high moments, μ/sub n/, n approx. 200, are needed. As I shall show, we use such moments as a matter of course, albeit without actually calculating them; in fact I will try to show that, if at all possible, the actual calculations of moments is to be avoided like the plague. At the heart of the new shell-model methods embodied in the Glasgow shell-model program and one or two similar ones is the so-called Lanczos method and this, it turns out, has many deep and subtle connections with the mathematical theory of moments. It is these connections that I will explore here

  5. Immediate Effects of Sports Taping Applied on the Lead Knee of Low- and High-Handicapped Golfers During Golf Swing.

    Science.gov (United States)

    Kim, Tae-Gyu; Kim, Eun-Kuk; Park, Jong-Chul

    2017-04-01

    Kim, T-G, Kim, E-K, and Park, J-C. Immediate effects of sports taping applied on the lead knee of low- and high-handicapped golfers during golf swing. J Strength Cond Res 31(4): 981-989, 2017-Elite golf athletes suffer from various musculoskeletal injuries due to repeated golf swings. Repetitive varus moment during golf swing has been suggested as a possible cause of injuries to the lead knee. The aim of this study was to objectively and quantitatively evaluate the immediate effects of sports taping on the lead knee of elite golfers to restrict varus moment. Thirty-one elite golfers were assigned to the low- (LHG, n = 15) or high-handicapped group (HHG, n = 16). Using 3-dimensional motion analysis, the lead knee position on the frontal plane with and without rigid taping (RT), elastic taping (ET), and placebo taping was identified in 4 separate phases by the 5 events of golf swing as follows: the peak of the backswing (E1), parallel to the ground during downswing (E2), ball impact (E3), parallel to the ground during follow-through (E4), and finish (E5). The LHG when using a driver club had decreased movement toward knee varus with RT and ET than that without it from E1 to E2 (p = 0.001). The LHG when using a 5-iron club decreased movement toward knee varus with RT than that without it from E1 to E2 (p = 0.006) and from E2 to E3 (p = 0.019). The HHG when using a driver club had decreased movement toward knee varus with RT from E1 to E2 (p = 0.014). Sports taping may be helpful for elite golfers in terms of reducing varus moment of the lead knee during the downswing and be useful for the development of preventive strategies for golf-related knee injuries.

  6. Influence of modern studded and bladed soccer boots and sidestep cutting on knee loading during match play conditions.

    Science.gov (United States)

    Kaila, Rajiv

    2007-09-01

    The influence of modern studded and bladed soccer boots and sidestep cutting on noncontact knee loading during match play conditions is not fully understood. Modern soccer boot type and sidestep cutting compared with straight-ahead running do not significantly influence knee internal tibia axial and valgus moments, anterior joint forces, and flexion angles. Controlled laboratory study. Fifteen professional male outfield soccer players undertook trials of straight-ahead running and sidestep cutting at 30 degrees and 60 degrees with a controlled approach velocity on a Fédération Internationale de Football Association (FIFA) approved soccer surface. Two bladed and 2 studded soccer boots from 2 manufacturers were investigated. Three-dimensional inverse dynamics analysis determined externally applied internal/external tibia axial and valgus/varus moments, anterior forces, and flexion angles throughout stance. The soccer boot type imparted no significant difference on knee loading for each maneuver. Internal tibia and valgus moments were significantly greater for sidestep cutting at 30 degrees and 60 degrees compared with straight-ahead running. Sidestep cutting at 60 degrees compared with straight-ahead running significantly increased anterior joint forces. Varying soccer boot type had no effect on knee loading for each maneuver, but sidestep cutting significantly increased internal tibia and valgus moments and anterior joint forces. Sidestep cutting, irrespective of the modern soccer boot type worn, may be implicated in the high incidence of noncontact soccer anterior cruciate ligament injuries by significantly altering knee loading.

  7. Patients Unicondylar Knee Replacement vs. Total Knee Replacement

    OpenAIRE

    Hedra Eskander

    2017-01-01

    The aim of this review article is to analyse the clinical effectiveness of total knee replacement (TKR) compared to unicondylar knee replacement (UKR) on patients. In terms of survival rates, revision rates and postoperative complications. The keywords used were: knee arthroplasty. Nearly three thousand articles were found on 25 August 2016. Of those, only twenty-five were selected and reviewed because they were strictly focused on the topic of this article. Compared with those who have TKR, ...

  8. Maximal Electric Dipole Moments of Nuclei with Enhanced Schiff Moments

    CERN Document Server

    Ellis, John; Pilaftsis, Apostolos

    2011-01-01

    The electric dipole moments (EDMs) of heavy nuclei, such as 199Hg, 225Ra and 211Rn, can be enhanced by the Schiff moments induced by the presence of nearby parity-doublet states. Working within the framework of the maximally CP-violating and minimally flavour-violating (MCPMFV) version of the MSSM, we discuss the maximal values that such EDMs might attain, given the existing experimental constraints on the Thallium, neutron and Mercury EDMs. The maximal EDM values of the heavy nuclei are obtained with the help of a differential-geometrical approach proposed recently that enables the maxima of new CP-violating observables to be calculated exactly in the linear approximation. In the case of 225Ra, we find that its EDM may be as large as 6 to 50 x 10^{-27} e.cm.

  9. Diphenyl-phosphinyl-morpholide (DPPM) lanthanide trifluoroacetate adducts

    International Nuclear Information System (INIS)

    Carvalho, L.R.F. de; Kim, D.J.

    1984-01-01

    Preparation and properties of adducts of lanthanide salts and diphenyl-phosphinyl-morpholide (DPPM) have been described in the literature. Addition compounds containing lanthanide nitrates, isothiocyanates, perchlorates, chlorides, bromides with DPPM have been obtained. In this article, the preparation and characterization of the addition compounds of lanthanide trifluoroacetates (TFA) with DPPM are reported. The compounds of general formula Ln (TFA) 3 . 3DPPM, Ln= La-Lu, Y were characterized by elemental analysis, melting ranges, infrared spectra, absorption and emission visible spectra, X-ray powder patterns. (Author) [pt

  10. Stability, accumulation and cytotoxicity of an albumin-cisplatin adduct

    DEFF Research Database (Denmark)

    Møller, Charlotte; Tastesen, Hanne Sørup; Gammelgaard, Bente

    2010-01-01

    The accumulation and cytotoxicity of a 10 µmol L¿¹ equimolar human serum albumin-cisplatin adduct (HSA-Pt) was investigated in suspension Ehrlich Ascites Tumor Cells (EATC) and adherent Ehrlich Lettré Ascites Cells (Lettré). HSA-Pt did not induce apoptosis nor was it taken up by the cells to any......-Pt and cisplatin were not stable in RPMI-1640 with 10% serum. The stability was determined using size exclusion chromatography-inductively coupled plasma-mass spectrometry (SEC-ICP-MS) and after 4 h new platinum peaks were observed. These findings indicate that before conducting cell experiments, the stability...

  11. EMG evaluation of hip adduction exercises for soccer players

    DEFF Research Database (Denmark)

    Serner, Andreas; Jakobsen, Markus Due; Andersen, Lars Louis

    2014-01-01

    INTRODUCTION: Exercise programmes are used in the prevention and treatment of adductor-related groin injuries in soccer; however, there is a lack of knowledge concerning the intensity of frequently used exercises. OBJECTIVE: Primarily to investigate muscle activity of adductor longus during six...... traditional and two new hip adduction exercises. Additionally, to analyse muscle activation of gluteals and abdominals. MATERIALS AND METHODS: 40 healthy male elite soccer players, training >5 h a week, participated in the study. Muscle activity using surface electromyography (sEMG) was measured bilaterally...

  12. Total knee arthroplasty for severe valgus knee deformity.

    Science.gov (United States)

    Zhou, Xinhua; Wang, Min; Liu, Chao; Zhang, Liang; Zhou, Yixin

    2014-01-01

    Primary total knee arthroplasty (TKA) in severe valgus knees may prove challenging, and choice of implant depends on the severity of the valgus deformity and the extent of soft-tissue release. The purpose of this study was to review 8 to 11 years (mean, 10 years) follow-up results of primary TKA for varient-III valgus knee deformity with use of different type implants. Between January 2002 and January 2005, 20 women and 12 men, aged 47 to 63 (mean, 57.19 ± 6.08) years old, with varient-III valgus knees underwent primary TKA. Of the 32 patients, 37 knees had varient-III deformities. Pie crusting was carefully performed with small, multiple inside-out incisions, bone resection balanced the knee in lieu of soft tissue releases that were not used in the series. Cruciate-retaining knees (Gemini MKII, Link Company, Germany) were used in 13 knees, Genesis II (Simth & Nephew Company, USA) in 14 knees, and hinged knee (Endo-Model Company, Germany) in 10 knees. In five patients with bilateral variant-III TKAs, three patients underwent 1-stage bilateral procedures, and two underwent 2-stage procedures. All implants were cemented and the patella was not resurfaced. The Hospital for Special Surgery (HSS) knee score was assessed. Patients were followed up from 8 to 11 years. The mean HSS knee score were improved from 50.33 ± 11.60 to 90.06 ± 3.07 (P managed with rivaroxaban and thrombo-embolic deterrent stockings. There was no incidence of pulmonary embolism. Post-operative patient satisfaction was 80.7 ± 10.4 points in the groups. Prosthetic survival rate was 100% at mean 10 years postoperative. Not only hinged implants can be successfully used in variant-III valgus knees. As our results show, if proper ligament balancing techniques are used and proper ligament balance is attained, the knee may not require the use of a more constrained components. Our results also present alternative implant choices for severe knee deformities.

  13. Subject-specific knee joint geometry improves predictions of medial tibiofemoral contact forces

    Science.gov (United States)

    Gerus, Pauline; Sartori, Massimo; Besier, Thor F.; Fregly, Benjamin J.; Delp, Scott L.; Banks, Scott A.; Pandy, Marcus G.; D’Lima, Darryl D.; Lloyd, David G.

    2013-01-01

    Estimating tibiofemoral joint contact forces is important for understanding the initiation and progression of knee osteoarthritis. However, tibiofemoral contact force predictions are influenced by many factors including muscle forces and anatomical representations of the knee joint. This study aimed to investigate the influence of subject-specific geometry and knee joint kinematics on the prediction of tibiofemoral contact forces using a calibrated EMG-driven neuromusculoskeletal model of the knee. One participant fitted with an instrumented total knee replacement walked at a self-selected speed while medial and lateral tibiofemoral contact forces, ground reaction forces, whole-body kinematics, and lower-limb muscle activity were simultaneously measured. The combination of generic and subject-specific knee joint geometry and kinematics resulted in four different OpenSim models used to estimate muscle-tendon lengths and moment arms. The subject-specific geometric model was created from CT scans and the subject-specific knee joint kinematics representing the translation of the tibia relative to the femur was obtained from fluoroscopy. The EMG-driven model was calibrated using one walking trial, but with three different cost functions that tracked the knee flexion/extension moments with and without constraint over the estimated joint contact forces. The calibrated models then predicted the medial and lateral tibiofemoral contact forces for five other different walking trials. The use of subject-specific models with minimization of the peak tibiofemoral contact forces improved the accuracy of medial contact forces by 47% and lateral contact forces by 7%, respectively compared with the use of generic musculoskeletal model. PMID:24074941

  14. Altered joint moment strategy during stair walking in diabetes patients with and without peripheral neuropathy.

    Science.gov (United States)

    Brown, Steven J; Handsaker, Joseph C; Maganaris, Constantinos N; Bowling, Frank L; Boulton, Andrew J M; Reeves, Neil D

    2016-05-01

    To investigate lower limb biomechanical strategy during stair walking in patients with diabetes and patients with diabetic peripheral neuropathy, a population known to exhibit lower limb muscular weakness. The peak lower limb joint moments of twenty-two patients with diabetic peripheral neuropathy and thirty-nine patients with diabetes and no neuropathy were compared during ascent and descent of a staircase to thirty-two healthy controls. Fifty-nine of the ninety-four participants also performed assessment of their maximum isokinetic ankle and knee joint moment (muscle strength) to assess the level of peak joint moments during the stair task relative to their maximal joint moment-generating capabilities (operating strengths). Both patient groups ascended and descended stairs slower than controls (pperipheral neuropathy were lower (pperipheral neuropathy compared to controls, and lower at knee only in patients without neuropathy. Operating strengths were higher (pneuropathy during stair descent compared to the controls, but not during stair ascent. Patients with diabetic peripheral neuropathy walk slower to alter gait strategy during stair walking and account for lower-limb muscular weakness, but still exhibit heightened operating strengths during stair descent, which may impact upon fatigue and the ability to recover a safe stance following postural instability. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  15. Tyrosine-lipid peroxide adducts from radical termination: para coupling and intramolecular Diels-Alder cyclization.

    Science.gov (United States)

    Shchepin, Roman; Möller, Matias N; Kim, Hye-young H; Hatch, Duane M; Bartesaghi, Silvina; Kalyanaraman, Balaraman; Radi, Rafael; Porter, Ned A

    2010-12-15

    Free radical co-oxidation of polyunsaturated lipids with tyrosine or phenolic analogues of tyrosine gave rise to lipid peroxide-tyrosine (phenol) adducts in both aqueous micellar and organic solutions. The novel adducts were isolated and characterized by 1D and 2D NMR spectroscopy as well as by mass spectrometry (MS). The spectral data suggest that the polyunsaturated lipid peroxyl radicals give stable peroxide coupling products exclusively at the para position of the tyrosyl (phenoxy) radicals. These adducts have characteristic (13)C chemical shifts at 185 ppm due to the cross-conjugated carbonyl of the phenol-derived cyclohexadienone. The primary peroxide adducts subsequently undergo intramolecular Diels-Alder (IMDA) cyclization, affording a number of diastereomeric tricyclic adducts that have characteristic carbonyl (13)C chemical shifts at ~198 ppm. All of the NMR HMBC and HSQC correlations support the structure assignments of the primary and Diels-Alder adducts, as does MS collision-induced dissociation data. Kinetic rate constants and activation parameters for the IMDA reaction were determined, and the primary adducts were reduced with cuprous ion to give a phenol-derived 4-hydroxycyclohexa-2,5-dienone. No products from adduction of peroxyls at the phenolic ortho position were found in either the primary or cuprous reduction product mixtures. These studies provide a framework for understanding the nature of lipid-protein adducts formed by peroxyl-tyrosyl radical-radical termination processes. Coupling of lipid peroxyl radicals with tyrosyl radicals leads to cyclohexenone and cyclohexadienone adducts, which are of interest in and of themselves since, as electrophiles, they are likely targets for protein nucleophiles. One consequence of lipid peroxyl reactions with tyrosyls may therefore be protein-protein cross-links via interprotein Michael adducts.

  16. Detection of Riddelliine-Derived DNA Adducts in Blood of Rats Fed Riddelliine

    Directory of Open Access Journals (Sweden)

    Ming W. Chou

    2002-09-01

    Full Text Available Abstract: We have previously shown that riddelliine, a naturally occurring genotoxic pyrrolizidine alkaloid, induces liver tumors in rats and mice through a genotoxic mechanism mediated by the formation of a set of eight 6,7-dihydro-7-hydroxy-1-hydroxymethyl-5Hpyrrolizine ( DHP-derived DNA adducts. In this study we report the formation of these DHP-derived DNA adducts in blood DNA of rats fed riddelliine. In an adduct formation and removal experiment, male and female F344 rats (8 weeks of age were administered riddelliine by gavage at a single dose of 10.0 mg/kg body weight in 0.1 M phosphate buffer. At 8, 24, 48, and 168 hrs after dosing, the levels of DHP-derived DNA adduct in blood and liver were determined by 32P-postlabeling/HPLC. Maximum DNA adduct formation occurred at 48 hr after treatment. From 48 to 168 hours, the adduct levels in female rat blood were 4-fold greater than those in male rats. In a dose response experiment, female rats were gavaged 0.1 and 1.0 mg/kg doses of riddelliine for three consecutive days and the DHPderived DNA adducts in blood DNA were assayed. The levels of the DHP-derived DNA adducts in blood of rats receiving 0.1 and 1.0 mg/kg doses were 12.9 and 51.8 adducts/107 nucleotides. These results suggest that: (i leucocyte DNA can bind with DHP to form a set of DHP-derived DNA adducts generated in liver; (ii DHP-derived DNA adducts in blood can serve as a potential non-invasive biomarkers for assessing the exposure to riddelliine.

  17. Ochratoxin A: In Utero Exposure in Mice Induces Adducts in Testicular DNA

    Directory of Open Access Journals (Sweden)

    Jamie E. Jennings-Gee

    2010-06-01

    Full Text Available Ochratoxin A (OTA is a nephrotoxin and carcinogen that is associated with Balkan endemic nephropathy and urinary tract tumors. OTA crosses the placenta and causes adducts in the liver and kidney DNA of newborns. Because the testis and kidney develop from the same embryonic tissue, we reasoned that OTA also may cause adducts transplacentally in the testis. We tested the hypothesis that acute exposure to OTA, via food and via exposure in utero, causes adducts in testicular DNA and that these lesions are identical to those that can be produced in the kidney and testis by the consumption of OTA. Adult mice received a single dose of OTA (from 0–1,056 µg/kg by gavage. Pregnant mice received a single i.p. injection of OTA (2.5 mg/kg at gestation day 17. DNA adducts were determined by 32P-postlabeling. Gavage-fed animals sacrificed after 48 hours accumulated OTA in kidney and testis and showed DNA adducts in kidney and testis. Some OTA metabolites isolated from the tissues were similar in both organs (kidney and testis. The litters of mice exposed prenatally to OTA showed no signs of overt toxicity. However, newborn and 1-month old males had DNA adducts in kidney and testis that were chromatographically similar to DNA adducts observed in the kidney and testis of gavage-fed adults. One adduct was identified previously as C8-dG-OTA adduct by LC MS/MS. No adducts were observed in males from dams not exposed to OTA. Our findings that in utero exposure to OTA causes adducts in the testicular DNA of male offspring support a possible role for OTA in testicular cancer.

  18. Helical axes of skeletal knee joint motion during running.

    Science.gov (United States)

    van den Bogert, A J; Reinschmidt, C; Lundberg, A

    2008-01-01

    The purpose of this study was to determine the changes in the axis of rotation of the knee that occur during the stance phase of running. Using intracortical pins, the three-dimensional skeletal kinematics of three subjects were measured during the stance phase of five running trials. The stance phase was divided into equal motion increments for which the position and orientation of the finite helical axes (FHA) were calculated relative to a tibial reference frame. Results were consistent within and between subjects. At the beginning of stance, the FHA was located at the midepicondylar point and during the flexion phase moved 20mm posteriorly and 10mm distally. At the time of peak flexion, the FHA shifted rapidly by about 10-20mm in proximal and posterior direction. The angle between the FHA and the tibial transverse plane increased gradually during flexion, to about 15 degrees of medial inclination, and then returned to zero at the start of the extension phase. These changes in position and orientation of FHA in the knee should be considered in analyses of muscle function during human movement, which require moment arms to be defined relative to a functional rotation axis. The finding that substantial changes in axis of rotation occurred independent of flexion angle suggests that musculoskeletal models must have more than one kinematic degree-of-freedom at the knee. The same applies to the design of knee prostheses, if the goal is to restore normal muscle function.

  19. NONINVASIVE DETERMINATION OF KNEE CARTILAGE DEFORMATION DURING JUMPING

    Directory of Open Access Journals (Sweden)

    Djordje Kosanic

    2009-12-01

    Full Text Available The purpose of this investigation was to use a combination of image processing, force measurements and finite element modeling to calculate deformation of the knee cartilage during jumping. Professional athletes performed jumps analyzed using a force plate and high-speed video camera system. Image processing was performed on each frame of video using a color recognition algorithm. A simplified mass-spring-damper model was utilized for determination of global force and moment on the knee. Custom software for fitting the coupling characteristics was created. Simulated results were used as input data for the finite element calculation of cartilage deformation in the athlete's knee. Computer simulation data was compared with the average experimental ground reaction forces. The results show the three-dimensional mechanical deformation distribution inside the cartilage volume. A combination of the image recognition technology, force plate measurements and the finite element cartilage deformation in the knee may be used in the future as an effective noninvasive tool for prediction of injury during jumping

  20. Muscle area of knee O.A

    International Nuclear Information System (INIS)

    Suzuki, Nobuharu; Onozawa, Toshihiro; Shibata, Minoru; Yamasita, Izumi; Kitsunai, Isamu; Asano, Akira

    1983-01-01

    The cross sectional area of the thigh muscles were studied by means of C.T. scan. Twelve normal knees, twelve primary knee O.A. knees, and six R.A. knees were examined. The cross sectional area of the Quadriceps femoris decreased significantly in the patient of the knee O.A. although flexors did not decrease. We discussed the etiology of the knee O.A. from this result. (author)

  1. The floating knee

    DEFF Research Database (Denmark)

    Muñoz Vives, Josep; Bel, Jean-Christophe; Capel Agundez, Arantxa

    2016-01-01

    In 1975, Blake and McBryde established the concept of 'floating knee' to describe ipsilateral fractures of the femur and tibia.1This combination is much more than a bone lesion; the mechanism is usually a high-energy trauma in a patient with multiple injuries and a myriad of other lesions...... fixation when both fractures (femoral and tibial) are extra-articular.Plates are the 'standard of care' in cases with articular fractures.A combination of implants are required by 40% of floating knees.Associated ligamentous and meniscal lesions are common, but may be irrelevant in the case of an intra......-articular fracture which gives the worst prognosis for this type of lesion. Cite this article: Muñoz Vives K, Bel J-C, Capel Agundez A, Chana Rodríguez F, Palomo Traver J, Schultz-Larsen M, Tosounidis, T. The floating knee.EFORT Open Rev2016;1:375-382. DOI: 10.1302/2058-5241.1.000042....

  2. The Critical Moment of Transition

    DEFF Research Database (Denmark)

    Svalgaard, Lotte

    2018-01-01

    By providing a holding environment to acknowledge sensitivities and address emotions, leadership programs prove to be powerful spaces for increasing self- and social awareness. However, the challenge is for one to maintain the newly gained self- and social awareness after leaving the holding...... environment and entering a context characterized by activity and performance. This is a frequently debated challenge for both academics and providers of management learning. Yet, critical moments in this transition remain under-exposed and under-researched. The contribution of this article is a research study......—within the context of an international MBA program—of MBA students applying their knowledge from a Leadership Stream in an international consultancy project. This article contributes to the theory and practice of management learning by providing a lens through which subjective experience of critical moments...

  3. Moment of truth for CMS

    CERN Multimedia

    2006-01-01

    One of the first events reconstructed in the Muon Drift Tubes, the Hadron Calorimeter and elements of the Silicon Tracker (TK) at 3 Tesla. The atmosphere in the CMS control rooms was electric. Everbody was at the helm for the first full-scale testing of the experiment. This was a crunch moment for the entire collaboration. On Tuesday, 22 August the magnet attained almost its nominal power of 4 Tesla! At the same moment, in a tiny improvised control room, the physicists were keyed up to test the entire detector system for the first time. The first cosmic ray tracks appeared on their screens in the week of 15 August. The tests are set to continue for several weeks more until the first CMS components are lowered into their final positions in the cavern.

  4. Three-dimensional kinematic and kinetic analysis of knee rotational stability in ACL-deficient patients during walking, running and pivoting

    DEFF Research Database (Denmark)

    Bohn, Marie Bagger; Petersen, Annemette Krintel; Nielsen, Dennis Brandborg

    2016-01-01

    BACKGROUND: Anterior cruciate ligament (ACL) deficiency leads to altered stability of the knee. The purpose of this study was to compare the dynamic, rotational stability of the knee, expressed as rotational stiffness, between anterior cruciate ligament-deficient (ACLD) knees, their contralateral......: The tibial internal rotation of the ACLD knee was not significantly different from the ACLI knee during all three tasks. During walking and running, the tibial rotation of the control group was significantly different from both legs of the ACL-injured patient. For pivoting, no difference in tibial rotation...... group. During running, the ACLI knee displayed a higher external moment than the ACLD and the healthy control group. This could indicate some type of protective strategy or muscular adaptation in the ACL-injured patients....

  5. Moment Distributions of Phase Type

    DEFF Research Database (Denmark)

    Bladt, Mogens; Nielsen, Bo Friis

    In this paper we prove that the class of distributions on the positive reals with a rational Laplace transform, also known as matrix-exponential distributions, is closed under formation of moment distributions. In particular, the results are hence valid for the well known class of phase-type dist...... alternative representation in terms of sub{intensity matrices. Finally we are able to nd explicit expressions for both the Lorenz curve and the Gini index....

  6. Electric Dipole Moments of Hadrons

    OpenAIRE

    Wirzba, Andreas

    2016-01-01

    A nonzero electric dipole moment (EDM) of the neutron, proton, deuteron, helion or any finite system necessarily involves the breaking of a symmetry, either by the presence of external fields (leading to the case of induced EDMs) or explicitly by the breaking of the discrete parity and time-reflection symmetries in the case of permanent EDMs. Recent - and in the case of the deuteron even unpublished - results for the relevant matrix elements of nuclear EDM operators are presented and the rel...

  7. Fullerene–Carbene Lewis Acid–Base Adducts

    KAUST Repository

    Li, Huaping

    2011-08-17

    The reaction between a bulky N-heterocylic carbene (NHC) and C60 leads to the formation of a thermally stable zwitterionic Lewis acid-base adduct that is connected via a C-C single bond. Low-energy absorption bands with weak oscillator strengths similar to those of n-doped fullerenes were observed for the product, consistent with a net transfer of electron density to the C60 core. Corroborating information was obtained using UV photoelectron spectroscopy, which revealed that the adduct has an ionization potential ∼1.5 eV lower than that of C60. Density functional theory calculations showed that the C-C bond is polarized, with a total charge of +0.84e located on the NHC framework and -0.84e delocalized on the C 60 cage. The combination of reactivity, characterization, and theoretical studies demonstrates that fullerenes can behave as Lewis acids that react with C-based Lewis bases and that the overall process describes n-doping via C-C bond formation. © 2011 American Chemical Society.

  8. Proteomic profiling of acrolein adducts in human lung epithelial cells

    Science.gov (United States)

    Spiess, Page C.; Deng, Bin; Hondal, Robert J.; Matthews, Dwight E.; van der Vliet, Albert

    2011-01-01

    Acrolein (2,3-propenal) is a major indoor and outdoor air pollutant originating largely from tobacco smoke or organic combustion. Given its high reactivity, the adverse effects of inhaled acrolein are likely due to direct interactions with the airway epithelium, resulting in altered epithelial function, but only limited information exists to date regarding the primary direct cellular targets for acrolein. Here, we describe a global proteomics approach to characterize the spectrum of airway epithelial protein targets for Michael adduction in acrolein-exposed bronchial epithelial (HBE1) cells, based on biotin hydrazide labeling and avidin purification of biotinylated proteins or peptides for analysis by LC-MS/MS. Identified protein targets included a number of stress proteins, cytoskeletal proteins, and several key proteins involved in redox signaling, including thioredoxin reductase, thioredoxin, peroxiredoxins, and glutathione S-transferase π. Because of the central role of thioredoxin reductase in cellular redox regulation, additional LC-MS/MS characterization was performed on purified mitochondrial thioredoxin reductase to identify the specific site of acrolein adduction, revealing the catalytic selenocysteine residue as the target responsible for enzyme inactivation. Our findings indicate that these approaches are useful in characterizing major protein targets for acrolein, and will enhance mechanistic understanding of the impact of acrolein on cell biology. PMID:21704744

  9. Kinetics, mechanism and thermodynamics of bisulfite-aldehyde adduct formation

    Energy Technology Data Exchange (ETDEWEB)

    Olson, T.M.; Boyce, S.D.; Hoffmann, M.R.

    1986-04-01

    The kinetics and mechanism of bisulfite addition to benzaldehyde were studied at low pH in order to assess the importance of this reaction in stabilizing S(IV) in fog-, cloud-, and rainwater. Previously, the authors established that appreciable concentrations of the formaldehyde-bisulfite adduct (HMSA) are often present in fogwater. Measured HMSA concentrations in fogwater often do not fully account for observed excess S(IV) concentrations, however, so that other S(IV)-aldehyde adducts may be present. Reaction rates were determined by monitoring the disappearance of benzaldehyde by U.V. spectrophotometry under pseudo-first order conditions, (S(IV))/sub T/ >>(phi-CHO)/sub T/, in the pH range 0 - 4.4 at 25/sup 0/C. The equilibrium constant was determined by dissolving the sodium salt of the addition compound in a solution adjusted to pH 3.9, and measuring the absorbance of the equilibrated solution at 250 nm. A literature value of the extinction coefficient for benzaldehyde was used to calculate the concentration of free benzaldehyde. All solutions were prepared under an N/sub 2/ atmosphere using deoxygenated, deionized water and ionic strength was maintained at 1.0 M with sodium chloride.

  10. Two novel creatinine adducts of andrographolide in human urine.

    Science.gov (United States)

    Qiu, Feng; Cui, Liang; Chen, Lixia; Sun, Jiawen; Yao, Xinsheng

    2012-09-01

    Andrographolide is a major labdane diterpenoid of the traditional Chinese and Ayurvedic medicine. Andrographis paniculate (Burm) Nees, is used in clinical situations in China mainly to treat fever, cold, and inflammation. In our previous study, fifteen metabolites of andrographolide were identified in human urine. However, there are still two other unknown metabolites. The aim of this study was to elucidate the structures of these two metabolites. 3. The two metabolites which are probably epimers were identified as creatinine adducts, and their structures were determined to be 14-deoxy-12-(creatinine-5-yl)-andrographolide-19-O-β-D-glucuronide A (Metabolite 1) and 14-deoxy-12-(creatinine-5-yl)-andrographolide-19-O-β-D-glucuronide B (Metabolite 2) by means of spectroscopic evidences. 4. It is for the first time that the formation of creatinine adducts as a novel metabolic pathway is reported. The mechanism was presumed that β-carbon (C-12) of α, β-unsaturated carbonyl was attacked by a 5-anion intermediate of creatinine formed through elimination of a proton, followed by the double bond migration from 12(13) to 13(14) and elimination of the hydroxyl group at C-14.

  11. Benzo(a)pyrene-DNA adduct formation in cells: time-dependent differences in the benzo(a)pyrene-DNA adducts present

    International Nuclear Information System (INIS)

    Baird, W.M.; Dumaswala, R.U.

    1980-01-01

    Procedures involving isolation of the DNA from tritium labelled hydrocarbon-treated cells are discussed. Enzymatic degradation of the DNA to deoxyribonucleosides, and chromatography of the adducts on columns of water gradients were covered as well

  12. Environmental air pollution and DNA adducts in Copenhagen bus drivers - effect of GSTM1 and NAT2 genotypes on adduct level

    DEFF Research Database (Denmark)

    Nielsen, Per Sabro; de Pater, Nettie; Okkels, Henrik

    1996-01-01

    The lymphocyte bulky PAH-DNA adduct levels have been studied in persons occupationally exposed to ambient air pollution. The exposure group consisted of 90 healthy, nonsmoking bus drivers from the Copenhagen area, divided into three exposure groups according to driving area, and 60 rural controls...... (smokers and non-smokers). PAH-DNA adducts were determined by 32P-postlabelling with the butanol enrichment procedure. The bus drivers answered a comprehensive questionnaire on passive smoking, residential area, diet and other potential confounding variables. A significantly higher adduct level...... was observed in bus drivers working in central Copenhagen (1.214 fmol/microg DNA, n = 49) compared with both those driving in the dormitory (median: 0.507 fmol/microg DNA, P = 0.046, n = 16) and suburban (median: 0.585 fmol/microg DNA, P = 0.041, n = 25) areas. All three groups had higher adduct levels than...

  13. Invariant hip moment pattern while walking with a robotic hip exoskeleton.

    Science.gov (United States)

    Lewis, Cara L; Ferris, Daniel P

    2011-03-15

    Robotic lower limb exoskeletons hold significant potential for gait assistance and rehabilitation; however, we have a limited understanding of how people adapt to walking with robotic devices. The purpose of this study was to test the hypothesis that people reduce net muscle moments about their joints when robotic assistance is provided. This reduction in muscle moment results in a total joint moment (muscle plus exoskeleton) that is the same as the moment without the robotic assistance despite potential differences in joint angles. To test this hypothesis, eight healthy subjects trained with the robotic hip exoskeleton while walking on a force-measuring treadmill. The exoskeleton provided hip flexion assistance from approximately 33% to 53% of the gait cycle. We calculated the root mean squared difference (RMSD) between the average of data from the last 15 min of the powered condition and the unpowered condition. After completing three 30-min training sessions, the hip exoskeleton provided 27% of the total peak hip flexion moment during gait. Despite this substantial contribution from the exoskeleton, subjects walked with a total hip moment pattern (muscle plus exoskeleton) that was almost identical and more similar to the unpowered condition than the hip angle pattern (hip moment RMSD 0.027, angle RMSD 0.134, p<0.001). The angle and moment RMSD were not different for the knee and ankle joints. These findings support the concept that people adopt walking patterns with similar joint moment patterns despite differences in hip joint angles for a given walking speed. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. The effect of age and knee osteoarthritis on muscle activation patterns and knee joint biomechanics during dual belt treadmill gait.

    Science.gov (United States)

    Rutherford, Derek; Baker, Matthew; Wong, Ivan; Stanish, William

    2017-06-01

    To compare a group of individuals with moderate medial compartment knee osteoarthritis (OA) to both an age-matched asymptomatic group of older adults and younger adults to determine whether differences in knee joint muscle activation patterns and joint biomechanics exist during gait between these three groups. 20 young adults, 20 older adults, and 40 individuals with moderate knee OA were recruited. Using standardized procedures, surface electromyograms were recorded from the vastus lateralis and medialis, rectus femoris and the medial and lateral hamstrings. All individuals walked on a dual belt instrumented treadmill while segment motions and ground reaction forces were recorded. Sagittal plane motion and net external sagittal and frontal plane moments were calculated. Discrete measures and principal component analyses extracted amplitude and temporal waveform features. Analysis of Variance models using Bonferroni corrections determined between and within group differences in these gait features (α=0.05). Individuals with knee OA have distinct biomechanics and muscle activation patterns when compared to age-matched asymptomatic adults and younger adults whereas differences between the young and older adults were few and included only measures of muscle activation amplitude. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Inert Reassessment Document for Poly(oxyethylene) adducts of mixed phytosterols

    Science.gov (United States)

    Poly(oxyethy1ene) adducts of mixed phytosterols is uncategorized as to list classification status. Based upon the reasonable certainty of no harm safety finding, the List 4B classification for poly(oxyethy1ene) adducts of mixed phytosterols is affirmed.

  16. 40 CFR 721.3700 - Fatty acid, ester with styrenated phenol, ethylene oxide adduct.

    Science.gov (United States)

    2010-07-01

    ... phenol, ethylene oxide adduct. 721.3700 Section 721.3700 Protection of Environment ENVIRONMENTAL..., ethylene oxide adduct. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified generically as fatty acid, ester with styrenated phenol, ethylene oxide...

  17. Effects of benzo[a]pyrene-DNA adducts on a reconstituted replication system

    International Nuclear Information System (INIS)

    Brown, W.C.; Romano, L.J.

    1991-01-01

    The authors have used a partially reconstituted replication system consisting of T7 DNA polymerase and T7 gene 4 protein to examine the effect of benzo[a]pyrene (B[a]P) adducts on DNA synthesis and gene 4 protein activities. The gene 4 protein is required for T7 DNA replication because of its ability to act as both a primase and helicase. They show here that total synthesis decreases as the level of adducts per molecule of DNA increases, suggesting that the B[a]P adducts are blocking an aspect of the replication process. By challenging synthesis on oligonucleotide-primed B[a]P-modified DNA with unmodified DNA, they present evidence that the T7 DNA polymerase freely dissociates after encountering an adduct. Prior studies have shown that the gene 4 protein alone does not dissociate from the template during translocation upon encountering an adduct. However, when gene 4 protein primed DNA synthesis is challenged, they observe an increase in synthesis but to a lesser extent than observed on oligonucleotide-primed synthesis. Finally, they have examined DNA synthesis on duplex templates and show the B[a]P adducts inhibit synthesis by the T7 DNA polymerase and gene 4 protein to the same extent regardless of whether the adducts are positioned in the leading or lagging strand, while synthesis by the polymerase alone is inhibited only when the adducts are in the template strand

  18. γIrradiation induced formation of PCB-solvent adducts in aliphatic solvents

    International Nuclear Information System (INIS)

    Lepine, F.; Milot, S.; Gagne, N.

    1990-01-01

    γIrradiation induced formation of PCB-solvent adducts was investigated as a model for PCB residues in irradiated food. Formation of cyclohexyl adducts of PCBs was found to be significant when pure PCB congeners and Aroclor mixture were irradiated in cyclohexane and cyclohexene. Reaction pathways were investigated, and the effects of oxygen and electron scavenger were studied

  19. Morphological analysis of the hindlimb in apes and humans. II. Moment arms

    Science.gov (United States)

    Payne, R C; Crompton, R H; Isler, K; Savage, R; Vereecke, E E; Günther, M M; Thorpe, S K S; D'Août, K

    2006-01-01

    Flexion/extension moment arms were obtained for the major muscles crossing the hip, knee and ankle joints in the orang-utan, gibbon, gorilla (Eastern and Western lowland) and bonobo. Moment arms varied with joint motion and were generally longer in proximal limb muscles than distal limb muscles. The shape of the moment arm curves (i.e. the plots of moment arm against joint angle) differed in different hindlimb muscles and in the same muscle in different subjects (both in the same and in different ape species). Most moment arms increased with increasing joint flexion, a finding which may be understood in the context of the employment of flexed postures by most non-human apes (except orang-utans) during both terrestrial and arboreal locomotion. When compared with humans, non-human great apes tended to have muscles better designed for moving the joints through large ranges. This was particularly true of the pedal digital flexors in orang-utans. In gibbons, the only lesser ape studied here, many of the moment arms measured were relatively short compared with those of great apes. This study was performed on a small sample of apes and thus differences noted here warrant further investigation in larger populations. PMID:16761974

  20. Genetic polymorphisms in catalase and CYP1B1 determine DNA adduct formation by bento(a)pyrene ex vivo

    NARCIS (Netherlands)

    Schults, Marten A.; Chiu, Roland K.; Nagle, Peter; Kleinjans, J C; van Schooten, Frederik Jan; Godschalk, Roger W.

    Genetic polymorphisms can partially explain the large inter-individual variation in DNA adduct levels following exposure to polycyclic aromatic hydrocarbons. Effects of genetic polymorphisms on DNA adduct formation are difficult to assess in human studies because exposure misclassification

  1. Moment Closure for the Stochastic Logistic Model

    National Research Council Canada - National Science Library

    Singh, Abhyudai; Hespanha, Joao P

    2006-01-01

    ..., which we refer to as the moment closure function. In this paper, a systematic procedure for constructing moment closure functions of arbitrary order is presented for the stochastic logistic model...

  2. Antigravity treadmill training during the early rehabilitation phase following unicompartmental knee arthroplasty: A case series.

    Science.gov (United States)

    Huang, Chun-Hao; Schroeder, E Todd; Powers, Christopher

    2018-02-26

    Patients who have undergone unicompartmental knee arthroplasty (UKA) have been reported to exhibit altered gait 19-25 months post-surgery. The most common gait impairment in this population is inadequate knee flexion and a corresponding decrease in the knee extensor moment during loading response (i.e., quadriceps avoidance). The purpose of this case series was to determine whether incorporation of antigravity treadmill training into a standard physical therapy program can eliminate quadriceps avoidance gait during the early rehabilitation phase following UKA. Four females who underwent UKA were recruited for this study. Participants completed antigravity treadmill training three times per week for 12 weeks in addition to their standard physical therapy program. Instrumented gait analysis was performed at baseline (pre-intervention), week 6 (mid-intervention), and week 12 (post-intervention). We found that peak knee flexion and the peak knee extensor moment during the weight acceptance phase of gait increased to normal values following the 12-week intervention period (14.1 ± 6.5° to 20.6 ± 1.5° and 0.4 ± 0.3 to 0.7 ± 0.2 Nm/kg respectively). The findings of this case series suggest that a standard physical therapy program that incorporates early gait training using an antigravity treadmill may be beneficial in eliminating "quadriceps avoidance" during the early rehabilitation phase following UKA.

  3. Magnification bone scan of knees for knee pain evaluation

    International Nuclear Information System (INIS)

    Lee, Myoung Hoon; Park, Chan H.; Yoon, Seok Nam; Hwang, Kyung Hoon

    2001-01-01

    Knee pain is one of the common complaints of patients seen in our orthopedic clinic. Routine anterior and posterior views of whole body bone scan (WBBS) is often not sufficient in the evaluation of these patients. An ideal bone scan using pinhole collimator or single photon emission tomography (SPECT), however, is impractical and time consuming in busy nuclear medicine department with limited resources. Therefore, the aim of the study is to assess limited bone scan of knees with magnification (LNSKM) for knee pain evaluation. Technical aspect of LBSKM and diagnostic efficacy are discussed on this poster. Adult patients with knee pain were reffered for LBSKM from an orthopedic surgen specializing knees. Four hundred fifteen LBSKMs were performed since 1999. patients were given 740 MBq (20mCi) Tc-99m MDP intravenously and 3 hours later LBSKM was performed using a low energy high resolution parallel hole collimator and Siemens Orbitor camera. (Simens medical systems. Inc., Hoffman Estates, III., USA). Anterior view of the knees was taken for 5 min, without magnification and both lateral views of symptomatic knees were obtained with electronic magnification (1.25, upto 2.0) for 8 min each. Disease processes such as DJD, traumatic arthritis, P-F tendonitis, SONK, meniscus tear are detected and illustrated along with normal knee scan finding. We believe LBSKM may not be as good as SPECT or pinhole imaging of the knees in the evaluation of knee pain but superior to routine WBBS in the nuclear medicine department with limited resources of instrumentation and manpower

  4. Line narrowing spectroscopic studies of DNA-carcinogen adducts and DNA-dye complexes

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Myungkoo [Iowa State Univ., Ames, IA (United States)

    1995-12-06

    Laser-induced fluorescence line narrowing and non-line narrowing spectroscopic methods were applied to conformational studies of stable DNA adducts of the 7β, 8α-dihydoxy-9α, l0α-epoxy-7,8,9, 10-tetrahydrobenzo[α]pyrene (anti-BPDE). Stereochemically distinct (+)-trans-, (-)-trans-, (+)-cis- and (-)-cis adducts of anti-BPDE bound to exocyclic amino group of the central guanine in an 11-mer oligonucleotide, exist in a mixture of conformations in frozen aqueous buffer matrices. The (+)-trans adduct adopts primarily an external conformation with a smaller fraction ( ~25 %) exists in a partially base-stacked conformation. Both cis adducts were found to be intercalated with significant π-π stacking interactions between the pyrenyl residues and the bases. Conformations of the trans-adduct of (+)-anti -BPDE in 11-mer oligonucleotides were studied as a function of flanking bases. In single stranded form the adduct at G2 or G3 (5 ft-flanking, base guanine) adopts a conformation with strong, interaction with the bases. In contrast, the adduct with a 5ft-flanking, thymine exists in a primarily helixexternal conformation. Similar differences were observed in the double stranded oligonucleotides. The nature of the 3ft-flanking base has little influence on the conformational equilibrium of the (+)-trans-anti BPDE-dG adduct. The formation and repair of BPDE-N2-dG in DNA isolated from the skin of mice treated topically with benzo[α]pyrene (BP) was studied. Low-temperature fluorescence spectroscopy of the intact DNA identified the major adduct as (+)-trans-anti-BPDE-N-dG, and the minor adduct fraction consisted mainly of (+)-cis-anti-BPDE-N2-dG.

  5. Line narrowing spectroscopic studies of DNA-carcinogen adducts and DNA-dye complexes

    International Nuclear Information System (INIS)

    Suh, Myungkoo.

    1995-01-01

    Laser-induced fluorescence line narrowing and non-line narrowing spectroscopic methods were applied to conformational studies of stable DNA adducts of the 7β, 8α-dihydoxy-9α, l0α-epoxy-7,8,9, 10-tetrahydrobenzo[α]pyrene (anti-BPDE). Stereochemically distinct (+)-trans-, (-)-trans-, (+)-cis- and (-)-cis adducts of anti-BPDE bound to exocyclic amino group of the central guanine in an 11-mer oligonucleotide, exist in a mixture of conformations in frozen aqueous buffer matrices. The (+)-trans adduct adopts primarily an external conformation with a smaller fraction ( ∼ 25 %) exists in a partially base-stacked conformation. Both cis adducts were found to be intercalated with significant π-π stacking interactions between the pyrenyl residues and the bases. Conformations of the trans-adduct of (+)-anti -BPDE in 11-mer oligonucleotides were studied as a function of flanking bases. In single stranded form the adduct at G 2 or G 3 (5 ft-flanking, base guanine) adopts a conformation with strong, interaction with the bases. In contrast, the adduct with a 5ft-flanking, thymine exists in a primarily helixexternal conformation. Similar differences were observed in the double stranded oligonucleotides. The nature of the 3ft-flanking base has little influence on the conformational equilibrium of the (+)-trans-anti BPDE-dG adduct. The formation and repair of BPDE-N 2 -dG in DNA isolated from the skin of mice treated topically with benzo[α]pyrene (BP) was studied. Low-temperature fluorescence spectroscopy of the intact DNA identified the major adduct as (+)-trans-anti-BPDE-N-dG, and the minor adduct fraction consisted mainly of (+)-cis-anti-BPDE-N 2 -dG

  6. Ankle and knee kinetics between strike patterns at common training speeds in competitive male runners.

    Science.gov (United States)

    Kuhman, Daniel; Melcher, Daniel; Paquette, Max R

    2016-01-01

    The purpose of this study was to investigate the interaction of foot strike and common speeds on sagittal plane ankle and knee joint kinetics in competitive rear foot strike (RFS) runners when running with a RFS pattern and an imposed forefoot strike (FFS) pattern. Sixteen competitive habitual male RFS runners ran at two different speeds (i.e. 8 and 6 min mile(-1)) using their habitual RFS and an imposed FFS pattern. A repeated measures analysis of variance was used to assess a potential interaction between strike pattern and speed for selected ground reaction force (GRF) variables and, sagittal plane ankle and knee kinematic and kinetic variables. No foot strike and speed interaction was observed for any of the kinetic variables. Habitual RFS yielded a greater loading rate of the vertical GRF, peak ankle dorsiflexor moment, peak knee extensor moment, peak knee eccentric extensor power, peak dorsiflexion and sagittal plane knee range of motion compared to imposed FFS. Imposed FFS yielded greater maximum vertical GRF, peak ankle plantarflexor moment, peak ankle eccentric plantarflexor power and sagittal plane ankle ROM compared to habitual RFS. Consistent with previous literature, imposed FFS in habitual RFS reduces eccentric knee extensor and ankle dorsiflexor involvement but produce greater eccentric ankle plantarflexor action compared to RFS. These acute differences between strike patterns were independent of running speeds equivalent to typical easy and hard training runs in competitive male runners. Current findings along with previous literature suggest differences in lower extremity kinetics between habitual RFS and imposed FFS running are consistent among a variety of runner populations.

  7. Automatic locking orthotic knee device

    Science.gov (United States)

    Weddendorf, Bruce C. (Inventor)

    1993-01-01

    An articulated tang in clevis joint for incorporation in newly manufactured conventional strap-on orthotic knee devices or for replacing such joints in conventional strap-on orthotic knee devices is discussed. The instant tang in clevis joint allows the user the freedom to extend and bend the knee normally when no load (weight) is applied to the knee and to automatically lock the knee when the user transfers weight to the knee, thus preventing a damaged knee from bending uncontrollably when weight is applied to the knee. The tang in clevis joint of the present invention includes first and second clevis plates, a tang assembly and a spacer plate secured between the clevis plates. Each clevis plate includes a bevelled serrated upper section. A bevelled shoe is secured to the tank in close proximity to the bevelled serrated upper section of the clevis plates. A coiled spring mounted within an oblong bore of the tang normally urges the shoes secured to the tang out of engagement with the serrated upper section of each clevic plate to allow rotation of the tang relative to the clevis plate. When weight is applied to the joint, the load compresses the coiled spring, the serrations on each clevis plate dig into the bevelled shoes secured to the tang to prevent relative movement between the tang and clevis plates. A shoulder is provided on the tang and the spacer plate to prevent overextension of the joint.

  8. Recruitment of knee joint ligaments

    NARCIS (Netherlands)

    Blankevoort, L.; Huiskes, H.W.J.; Lange, de A.

    1991-01-01

    On the basis of earlier reported data on the in vitro kinematics of passive knee-joint motions of four knee specimens, the length changes of ligament fiber bundles were determined by using the points of insertion on the tibia and femur. The kinematic data and the insertions of the ligaments were

  9. Somatosensory abnormalities in knee OA.

    Science.gov (United States)

    Wylde, Vikki; Palmer, Shea; Learmonth, Ian D; Dieppe, Paul

    2012-03-01

    The aim of this study was to use quantitative sensory testing (QST) to explore the range and prevalence of somatosensory abnormalities demonstrated by patients with advanced knee OA. One hundred and seven knee OA patients and 50 age- and sex-matched healthy participants attended a 1-h QST session. Testing was performed on the medial side of the knee and the pain-free forearm. Light-touch thresholds were assessed using von Frey filaments, pressure pain thresholds using a digital pressure algometer, and thermal sensation and pain thresholds using a Thermotest MSA. Significant differences in median threshold values from knee OA patients and healthy participants were identified using Mann-Whitney U-tests. The z-score transformations were used to determine the prevalence of the different somatosensory abnormalities in knee OA patients. Testing identified 70% of knee OA patients as having at least one somatosensory abnormality. Comparison of median threshold values between knee OA patients and healthy participants revealed that patients had localized thermal and tactile hypoaesthesia and pressure hyperalgesia at the osteoarthritic knee. Tactile hypoaesthesia and pressure hyperalgesia were also present at the pain-free forearm. The most prevalent somatosensory abnormalities were tactile hypoaesthesia and pressure hyperalgesia, evident in between 20 and 34% of patients. This study found that OA patients demonstrate an array of somatosensory abnormalities, of which the most prevalent were tactile hypoaesthesia and pressure hyperalgesia. Further research is now needed to establish the clinical implications of these somatosensory abnormalities.

  10. Effect of knee joint icing on knee extension strength and knee pain early after total knee arthroplasty: a randomized cross-over study.

    Science.gov (United States)

    Holm, Bente; Husted, Henrik; Kehlet, Henrik; Bandholm, Thomas

    2012-08-01

    To investigate the acute effect of knee joint icing on knee extension strength and knee pain in patients shortly after total knee arthroplasty. A prospective, single-blinded, randomized, cross-over study. A fast-track orthopaedic arthroplasty unit at a university hospital. Twenty patients (mean age 66 years; 10 women) scheduled for primary unilateral total knee arthroplasty. The patients were treated on two days (day 7 and day 10) postoperatively. On one day they received 30 minutes of knee icing (active treatment) and on the other day they received 30 minutes of elbow icing (control treatment). The order of treatments was randomized. Maximal knee extension strength (primary outcome), knee pain at rest and knee pain during the maximal knee extensions were measured 2-5 minutes before and 2-5 minutes after both treatments by an assessor blinded for active or control treatment. The change in knee extension strength associated with knee icing was not significantly different from that of elbow icing (knee icing change (mean (1 SD)) -0.01 (0.07) Nm/kg, elbow icing change -0.02 (0.07) Nm/kg, P = 0.493). Likewise, the changes in knee pain at rest (P = 0.475), or knee pain during the knee extension strength measurements (P = 0.422) were not different between treatments. In contrast to observations in experimental knee effusion models and inflamed knee joints, knee joint icing for 30 minutes shortly after total knee arthroplasty had no acute effect on knee extension strength or knee pain.

  11. On the interpretation of the support moment

    NARCIS (Netherlands)

    Hof, AL

    2000-01-01

    It has been suggested by Winter (J. Biomech. 13 (1980) 923-927) that the 'support moment', the sum of the sagittal extension moments, shows less variability in walking than any of the joint moments separately. A simple model is put forward to explain this finding. It is proposed to reformulate the

  12. Immediate effects of a new microprocessor-controlled prosthetic knee joint: a comparative biomechanical evaluation.

    Science.gov (United States)

    Bellmann, Malte; Schmalz, Thomas; Ludwigs, Eva; Blumentritt, Siegmar

    2012-03-01

    To investigate the immediate biomechanical effects after transition to a new microprocessor-controlled prosthetic knee joint. Intervention cross-over study with repeated measures. Only prosthetic knee joints were changed. Motion analysis laboratory. Men (N=11; mean age ± SD, 36.7±10.2y; Medicare functional classification level, 3-4) with unilateral transfemoral amputation. Two microprocessor-controlled prosthetic knee joints: C-Leg and a new prosthetic knee joint, Genium. Static prosthetic alignment, time-distance parameters, kinematic and kinetic parameters, and center of pressure. After a half-day training and an additional half-day accommodation, improved biomechanical outcomes were demonstrated by the Genium: lower ground reaction forces at weight acceptance during level walking at various velocities, increased swing phase flexion angles during walking on a ramp, and level walking with small steps. Maximum knee flexion angle during swing phase at various velocities was nearly equal for Genium. Step-over-step stair ascent with the Genium knee was more physiologic as demonstrated by a more equal load distribution between the prosthetic and contralateral sides and a more natural gait pattern. When descending stairs and ramps, knee flexion moments with the Genium tended to increase. During quiet stance on a decline, subjects using Genium accepted higher loading of the prosthetic side knee joint, thus reducing same side hip joint loading as well as postural sway. In comparision to the C-Leg, the Genium demonstrated immediate biomechanical advantages during various daily ambulatory activities, which may lead to an increase in range and diversity of activity of people with above-knee amputations. Results showed that use of the Genium facilitated more natural gait biomechanics and load distribution throughout the affected and sound musculoskeletal structure. This was observed during quiet stance on a decline, walking on level ground, and walking up and down ramps and

  13. Overuse Knee Injuries in Athletes

    Directory of Open Access Journals (Sweden)

    Miroslav Kezunović

    2013-03-01

    Full Text Available According to many statistics over 55% of all sports-related injuries are incurred in the knee joint (active sportsmen and recreationists. The statistics definitely differ, depending on type of sport and specific movements habitually performed in a particular sport. Therefore, in addition to acute knee injuries overuse syndromes are common in the knee area also due to specificities of patellofemoral joint just because specific diseases like „jumper's knee“ and „runner's knee“ are related to certain sport activities. Generally speaking, these syndromes occur due to poor orientation of the knee extensor mechanism, i.e. friction of iliotibial band and patellofemoral chondromalacia. It is believed that about 45% of all overuse syndromes in the knee area occur as a result of running.

  14. MR findings in knee osteoarthritis

    International Nuclear Information System (INIS)

    Guermazi, Ali; Taouli, Bachir; Genant, Harry K.; Zaim, Souhil; Miaux, Yves; Peterfy, Charles G.

    2003-01-01

    Knee osteoarthritis (OA) is a leading cause of disability. Recent advances in drug discovery techniques and improvements in understanding the pathophysiology of osteoarthritic disorders have resulted in an unprecedented number of new therapeutic agents. Of all imaging modalities, radiography has been the most widely used for the diagnosis and management of the progression of knee OA. Magnetic resonance imaging is a relatively recent technique and its applications to osteoarthritis have been limited. Compared with conventional radiography, MR imaging offers unparalleled discrimination among articular soft tissues by directly visualizing all components of the knee joint simultaneously and therefore allowing the knee joint to be evaluated as a whole organ. In this article we present the MR findings in knee OA including cartilage abnormalities, osteophytes, bone edema, subarticular cysts, bone attrition, meniscal tears, ligament abnormalities, synovial thickening, joint effusion, intra-articular loose bodies, and periarticular cysts. (orig.)

  15. Anterior knee pain

    International Nuclear Information System (INIS)

    LLopis, Eva; Padron, Mario

    2007-01-01

    Anterior knee pain is a common complain in all ages athletes. It may be caused by a large variety of injuries. There is a continuum of diagnoses and most of the disorders are closely related. Repeated minor trauma and overuse play an important role for the development of lesions in Hoffa's pad, extensor mechanism, lateral and medial restrain structures or cartilage surface, however usually an increase or change of activity is referred. Although the direct relation of cartilage lesions, especially chondral, and pain is a subject of debate these lesions may be responsible of early osteoarthrosis and can determine athlete's prognosis. The anatomy and biomechanics of patellofemoral joint is complex and symptoms are often unspecific. Transient patellar dislocation has MR distinct features that provide evidence of prior dislocation and rules our complication. However, anterior knee pain more often is related to overuse and repeated minor trauma. Patella and quadriceps tendon have been also implicated in anterior knee pain, as well as lateral or medial restraint structures and Hoffa's pad. US and MR are excellent tools for the diagnosis of superficial tendons, the advantage of MR is that permits to rule out other sources of intraarticular derangements. Due to the complex anatomy and biomechanic of patellofemoral joint maltracking is not fully understood; plain films and CT allow the study of malalignment, new CT and MR kinematic studies have promising results but further studies are needed. Our purpose here is to describe how imaging techniques can be helpful in precisely defining the origin of the patient's complaint and thus improve understanding and management of these injuries

  16. Anterior knee pain

    Energy Technology Data Exchange (ETDEWEB)

    LLopis, Eva [Hospital de la Ribera, Alzira, Valencia (Spain) and Carretera de Corbera km 1, 46600 Alzira Valencia (Spain)]. E-mail: ellopis@hospital-ribera.com; Padron, Mario [Clinica Cemtro, Ventisquero de la Condesa no. 42, 28035 Madrid (Spain)]. E-mail: mario.padron@clinicacemtro.com

    2007-04-15

    Anterior knee pain is a common complain in all ages athletes. It may be caused by a large variety of injuries. There is a continuum of diagnoses and most of the disorders are closely related. Repeated minor trauma and overuse play an important role for the development of lesions in Hoffa's pad, extensor mechanism, lateral and medial restrain structures or cartilage surface, however usually an increase or change of activity is referred. Although the direct relation of cartilage lesions, especially chondral, and pain is a subject of debate these lesions may be responsible of early osteoarthrosis and can determine athlete's prognosis. The anatomy and biomechanics of patellofemoral joint is complex and symptoms are often unspecific. Transient patellar dislocation has MR distinct features that provide evidence of prior dislocation and rules our complication. However, anterior knee pain more often is related to overuse and repeated minor trauma. Patella and quadriceps tendon have been also implicated in anterior knee pain, as well as lateral or medial restraint structures and Hoffa's pad. US and MR are excellent tools for the diagnosis of superficial tendons, the advantage of MR is that permits to rule out other sources of intraarticular derangements. Due to the complex anatomy and biomechanic of patellofemoral joint maltracking is not fully understood; plain films and CT allow the study of malalignment, new CT and MR kinematic studies have promising results but further studies are needed. Our purpose here is to describe how imaging techniques can be helpful in precisely defining the origin of the patient's complaint and thus improve understanding and management of these injuries.

  17. Electric and Magnetic Dipole Moments

    CERN Document Server

    CERN. Geneva

    2005-01-01

    The stringent limit on the electric dipole moment of the neutron forced the issue on the strong CP-problem. The most elegant solution of which is the axion field proposed by Peccei and Quinn. The current limit on the QCD parameter theta coming from the limit on the neutron EDM is of order 10-10. I am going to describe the present status on the neutron EDM searches and further prospects on getting down to theta_qcd sensitivity of 10-13 with the new deuteron EDM in storage rings proposal. For completeness the current status and prospects of the muon g-2 experiment will also be given.

  18. The Muon Electric Dipole Moment

    OpenAIRE

    Barger, Vernon; Kao, Chung; Das, Ashok

    1997-01-01

    The electric dipole moment of the muon ($d_\\mu$) is evaluated in a two Higgs doublet model with a softly broken discrete symmetry. For $\\tan\\beta \\equiv |v_2|/|v_1| \\sim 1$, contributions from two loop diagrams involving the $t$ quark and the $W$ boson dominate; while for $\\tan\\beta \\gsim 10$, contributions from two loop diagrams involving the $b$ quark and the $\\tau$ lepton are dominant. For $8 \\gsim \\tan\\beta \\gsim 4$, significant cancellation occurs among the contributions from two loop di...

  19. Knees Lifted High

    Centers for Disease Control (CDC) Podcasts

    2008-08-04

    The Eagle Books are a series of four books that are brought to life by wise animal characters - Mr. Eagle, Miss Rabbit, and Coyote - who engage Rain That Dances and his young friends in the joy of physical activity, eating healthy foods, and learning from their elders about health and diabetes prevention. Knees Lifted High gives children fun ideas for active outdoor play.  Created: 8/4/2008 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 8/5/2008.

  20. Correlation between hip function and knee kinematics evaluated by three-dimensional motion analysis during lateral and medial side-hopping.

    Science.gov (United States)

    Itoh, Hiromitsu; Takiguchi, Kohei; Shibata, Yohei; Okubo, Satoshi; Yoshiya, Shinichi; Kuroda, Ryosuke

    2016-09-01

    [Purpose] Kinematic and kinetic characteristics of the limb during side-hopping and hip/knee interaction during this motion have not been clarified. The purposes of this study were to examine the biomechanical parameters of the knee during side hop and analyze its relationship with clinical measurements of hip function. [Subjects and Methods] Eleven male college rugby players were included. A three-dimensional motion analysis system was used to assess motion characteristics of the knee during side hop. In addition, hip range of motion and muscle strength were evaluated. Subsequently, the relationship between knee motion and the clinical parameters of the hip was analyzed. [Results] In the lateral touchdown phase, the knee was positioned in an abducted and externally rotated position, and increasing abduction moment was applied to the knee. An analysis of the interaction between knee motion and hip function showed that range of motion for hip internal rotation was significantly correlated with external rotation angle and external rotation/abduction moments of the knee during the lateral touchdown phase. [Conclusion] Range of motion for hip internal rotation should be taken into consideration for identifying the biomechanical characteristics in the side hop test results.

  1. Importance of tibial slope for stability of the posterior cruciate ligament deficient knee.

    Science.gov (United States)

    Giffin, J Robert; Stabile, Kathryne J; Zantop, Thore; Vogrin, Tracy M; Woo, Savio L-Y; Harner, Christopher D

    2007-09-01

    Previous studies have shown that increasing tibial slope can shift the resting position of the tibia anteriorly. As a result, sagittal osteotomies that alter slope have recently been proposed for treatment of posterior cruciate ligament (PCL) injuries. Increasing tibial slope with an osteotomy shifts the resting position anteriorly in a PCL-deficient knee, thereby partially reducing the posterior tibial "sag" associated with PCL injury. This shift in resting position from the increased slope causes a decrease in posterior tibial translation compared with the PCL-deficient knee in response to posterior tibial and axial compressive loads. Controlled laboratory study. Three knee conditions were tested with a robotic universal force-moment sensor testing system: intact, PCL-deficient, and PCL-deficient with increased tibial slope. Tibial slope was increased via a 5-mm anterior opening wedge osteotomy. Three external loading conditions were applied to each knee condition at 0 degrees, 30 degrees, 60 degrees, 90 degrees, and 120 degrees of knee flexion: (1) 134-N anterior-posterior (A-P) tibial load, (2) 200-N axial compressive load, and (3) combined 134-N A-P and 200-N axial loads. For each loading condition, kinematics of the intact knee were recorded for the remaining 5 degrees of freedom (ie, A-P, medial-lateral, and proximal-distal translations, internal-external and varus-valgus rotations). Posterior cruciate ligament deficiency resulted in a posterior shift of the tibial resting position to 8.4 +/- 2.6 mm at 90 degrees compared with the intact knee. After osteotomy, tibial slope increased from 9.2 degrees +/- 1.0 degrees in the intact knee to 13.8 degrees +/- 0.9 degrees. This increase in slope reduced the posterior sag of the PCL-deficient knee, shifting the resting position anteriorly to 4.0 +/- 2.0 mm at 90 degrees. Under a 200-N axial compressive load with the osteotomy, an additional increase in anterior tibial translation to 2.7 +/- 1.7 mm at 30 degrees was

  2. Self-reported previous knee injury and low knee function increase knee injury risk in adolescent female football.

    Science.gov (United States)

    Clausen, M B; Tang, L; Zebis, M K; Krustrup, P; Hölmich, P; Wedderkopp, N; Andersen, L L; Christensen, K B; Møller, M; Thorborg, K

    2016-08-01

    Knee injuries are common in adolescent female football. Self-reported previous knee injury and low Knee injury and Osteoarthritis Outcome Score (KOOS) are proposed to predict future knee injuries, but evidence regarding this in adolescent female football is scarce. The aim of this study was to investigate self-reported previous knee injury and low KOOS subscale score as risk factors for future knee injuries in adolescent female football. A sample of 326 adolescent female football players, aged 15-18, without knee injury at baseline, were included. Data on self-reported previous knee injury and KOOS questionnaires were collected at baseline. Time-loss knee injuries and football exposures were reported weekly by answers to standardized text-message questions, followed by injury telephone interviews. A priori, self-reported previous knee injury and low KOOS subscale scores (female football. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Investigation of benzo(a)pyrene-globin adducts

    Energy Technology Data Exchange (ETDEWEB)

    Wallin, H; Jeffre, A M; Santella, R M

    1987-05-01

    The nature of the adducts formed between benzo(a)pyrene (BP) and globin were investigated in animals treated with (/sup 3/H)BP. Modification levels on globin were determined by radioactivity measurements. Since BP tetraols can be released from benzo(a)pyrene diol epoxide modified protein and DNA by acid treatment, globin samples were treated with acid, released tetraols separated by HPLC and quantitated by scintillation counting. In addition, acid released material was measured in competitive enzyme linked immunosorbent assay (ELISA) using antibodies which recognize BP tetraols. Both measurements indicate that only 2% of bound radioactivity could be released as free BP tetraols. These studies indicate that benzo(a)pyrene diol epoxide may not be the major metabolite of BP involved in globin binding. (author). 14 refs.

  4. Vitamin A-aldehyde adducts: AMD risk and targeted therapeutics.

    Science.gov (United States)

    Sparrow, Janet R

    2016-04-26

    Although currently available treatment options for age-related macular degeneration (AMD) are limited, particularly for atrophic AMD, the identification of predisposing genetic variations has informed clinical studies addressing therapeutic options such as complement inhibitors and anti-inflammatory agents. To lower risk of early AMD, recommended lifestyle interventions such as the avoidance of smoking and the intake of low glycemic antioxidant-rich diets have largely followed from the identification of nongenetic modifiable factors. On the other hand, the challenge of understanding the complex relationship between aging and cumulative damage leading to AMD has fueled investigations of the visual cycle adducts that accumulate in retinal pigment epithelial (RPE) cells and are a hallmark of aging retina. These studies have revealed properties of these compounds that provide insights into processes that may compromise RPE and could contribute to disease mechanisms in AMD. This work has also led to the design of targeted therapeutics that are currently under investigation.

  5. Wearable Inertial Sensors Allow for Quantitative Assessment of Shoulder and Elbow Kinematics in a Cadaveric Knee Arthroscopy Model.

    Science.gov (United States)

    Rose, Michael; Curtze, Carolin; O'Sullivan, Joseph; El-Gohary, Mahmoud; Crawford, Dennis; Friess, Darin; Brady, Jacqueline M

    2017-12-01

    To develop a model using wearable inertial sensors to assess the performance of orthopaedic residents while performing a diagnostic knee arthroscopy. Fourteen subjects performed a diagnostic arthroscopy on a cadaveric right knee. Participants were divided into novices (5 postgraduate year 3 residents), intermediates (5 postgraduate year 4 residents), and experts (4 faculty) based on experience. Arm movement data were collected by inertial measurement units (Opal sensors) by securing 2 sensors to each upper extremity (dorsal forearm and lateral arm) and 2 sensors to the trunk (sternum and lumbar spine). Kinematics of the elbow and shoulder joints were calculated from the inertial data by biomechanical modeling based on a sequence of links connected by joints. Range of motion required to complete the procedure was calculated for each group. Histograms were used to compare the distribution of joint positions for an expert, intermediate, and novice. For both the right and left upper extremities, skill level corresponded well with shoulder abduction-adduction and elbow prono-supination. Novices required on average 17.2° more motion in the right shoulder abduction-adduction plane than experts to complete the diagnostic arthroscopy (P = .03). For right elbow prono-supination (probe hand), novices required on average 23.7° more motion than experts to complete the procedure (P = .03). Histogram data showed novices had markedly more variability in shoulder abduction-adduction and elbow prono-supination compared with the other groups. Our data show wearable inertial sensors can measure joint kinematics during diagnostic knee arthroscopy. Range-of-motion data in the shoulder and elbow correlated inversely with arthroscopic experience. Motion pattern-based analysis shows promise as a metric of resident skill acquisition and development in arthroscopy. Wearable inertial sensors show promise as metrics of arthroscopic skill acquisition among residents. Copyright © 2017

  6. Formation of monofunctional cisplatin-DNA adducts in carbonate buffer.

    Science.gov (United States)

    Binter, Alexandra; Goodisman, Jerry; Dabrowiak, James C

    2006-07-01

    Carbonate in its various forms is an important component in blood and the cytosol. Since, under conditions that simulate therapy, carbonate reacts with cisplatin to form carbonato complexes, one of which is taken up and/or modified by the cell [C.R. Centerwall, J. Goodisman, D.J. Kerwood, J. Am. Chem. Soc., 127 (2005) 12768-12769], cisplatin-carbonato complexes may be important in the mechanism of action of cisplatin. In this report we study the binding of cisplatin to pBR322 DNA in two different buffers, using gel electrophoresis. In 23.8mM HEPES, N-(2-hydroxyethyl)-piperazine-N'-2-ethanesulfonic acid, 5mM NaCl, pH 7.4 buffer, cisplatin produces aquated species, which react with DNA to unwind supercoiled Form I DNA, increasing its mobility, and reducing the binding of ethidium to DNA. This behavior is consistent with the formation of the well-known intrastrand crosslink on DNA. In 23.8mM carbonate buffer, 5mM NaCl, pH 7.4, cisplatin forms carbonato species that produce DNA-adducts which do not significantly change supercoiling but enhance binding of ethidium to DNA. This behavior is consistent with the formation of a monofunctional cisplatin adduct on DNA. These results show that aquated cisplatin and carbonato complexes of cisplatin produce different types of lesions on DNA and they underscore the importance of carrying out binding studies with cisplatin and DNA using conditions that approximate those found in the cell.

  7. Paracetamol (acetaminophen) protein adduct concentrations during therapeutic dosing.

    Science.gov (United States)

    Heard, Kennon; Green, Jody L; Anderson, Victoria; Bucher-Bartelson, Becki; Dart, Richard C

    2016-03-01

    Paracetamol protein adducts (PPA) are a biomarker of paracetamol exposure. PPA are quantified as paracetamol-cysteine (APAP-CYS), and concentrations above 1.1 μmol l(-1) have been suggested as a marker of paracetamol-induced hepatotoxicity. However, there is little information on the range of concentrations observed during prolonged therapeutic dosing. The aim of the present study was to describe the concentration of PPA in the serum of subjects taking therapeutic doses of paracetamol for at least 16 days. Preplanned secondary aim of a prospective randomized controlled (placebo vs. 4g day(-1) paracetamol) trial. We measured subjects' serum PPA concentrations every 3 days for a minimum of 16 days. We also measured concentrations on study days 1-3 and 16-25 in subsets of patients. PPA were quantified as APAP-CYS after gel filtration and protein digestion using liquid chromatography/mass spectrometry. Ninety per cent of subjects had detectable PPA after five doses. Median APAP-CYS concentrations in paracetamol-treated subjects increased to a plateau of 0.1 μmol l(-1) on day 7, where they remained. The highest concentration measured was 1.1 μmol l(-1) and two subjects never had detectable PPA levels. PPA were detected in the serum of 78% of subjects 9 days after their final dose. PPA are detectable in the vast majority of subjects taking therapeutic doses of paracetamol. While most have concentrations well below the threshold associated with hepatotoxicity, concentrations may approach 1.1 μmol l(-1) in rare cases. Adducts are detectable after a few doses and can persist for over a week after dosing is stopped. © 2015 The British Pharmacological Society.

  8. Forefoot Adduction Is a Risk Factor for Jones Fracture.

    Science.gov (United States)

    Fleischer, Adam E; Stack, Rebecca; Klein, Erin E; Baker, Jeffrey R; Weil, Lowell; Weil, Lowell Scott

    Jones fractures are among the most common fractures of the foot; however, much remains unknown about their etiology. The purpose of the present study was to further examine the risk factors of forefoot and hindfoot alignment on Jones fractures using an epidemiologic study design. We used a retrospective, matched, case-control study design. Cases consisted of patients with acute, isolated Jones fractures confirmed on plain film radiographs seen at our institute from January 2009 to December 2013. Patients presenting with pain unrelated to metatarsal fractures served as controls. Controls were matched to cases by age (±2 years), gender, and year of presentation. Weightbearing foot radiographs were assessed for 13 angular relationships by a single rater. Conditional multivariable logistic regression was used to identify important risk factors. Fifty patients with acute Jones fractures and 200 controls were included. The only significant variables in the final multivariable model were the metatarsus adductus angle (odds ratio [OR] 1.16, 95% confidence interval [CI] 1.08 to 1.25) and fourth/fifth intermetatarsal angle (OR 0.69, 95% CI 0.57 to 0.83)-both measures of static forefoot adduction. The presence of metatarsus adductus (defined as >15°) on foot radiographs was associated with a 2.4 times greater risk of a Jones fracture (adjusted OR 2.4, 95% CI 1.2 to 4.8). We have concluded that the risk of Jones fracture increases with an adducted forefoot posture. In our population, which consisted primarily of patients presenting after a fall (10 of 50; 20%) or misstep/inversion injury (19 of 50; 38%), the hindfoot alignment appeared to be a less important factor. Copyright © 2017 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  9. Reconstruction of convex bodies from moments

    DEFF Research Database (Denmark)

    Hörrmann, Julia; Kousholt, Astrid

    We investigate how much information about a convex body can be retrieved from a finite number of its geometric moments. We give a sufficient condition for a convex body to be uniquely determined by a finite number of its geometric moments, and we show that among all convex bodies, those which......- rithm that approximates a convex body using a finite number of its Legendre moments. The consistency of the algorithm is established using the stabil- ity result for Legendre moments. When only noisy measurements of Legendre moments are available, the consistency of the algorithm is established under...

  10. Adduction of acrylamide with biomacromolecules at environmental dose level measured by accelerator mass spectrometry (AMS)

    International Nuclear Information System (INIS)

    Xie, Q.Y.; Sun, H.F.; Liu, Y.F.; Ding, X.F.; Fu, D.P.; Liu, K.X.

    2005-01-01

    Acrylamide (AA) is a well-known neurotoxin, which also has developmental, reproductive as well as genetic toxicity. AA has been classified as a probable human carcinogen by IARC in 1994 since its carcinogenic effects in animals were reported after repetitive high level dosing. Over the last 10 years, there have been a large number of studies investigating the effects of AA on rodent reproductive performance. In 2002, the Swedish Food Administration reported the presence of AA in the heat-treated food products. which again elicited great concern on the toxicity of AA. However most of these studies were investigated at a dose level of mg/kg b.w and above, which is much higher than the actual human relevant dose. In this study we investigate the adduction of environmental level AA with biomacromolecules by the ultra-sensitive AMS technique. This may provide some information on the reproductive toxicity of AA under extremely low level exposure. A series doses of [2, 3- 14 C] AA (0, 0.1, 1, 10, 100, 250, 1000 μg/kg bw) were administrated with a single intraperitoneal injection (i.p.) to ICR adult male mice. The blood and spermatozoon were collected 24 h post dosing. Hemoglobin (Hb), serum albumin (SA), protamine, spermatozoon DNA, spermatozoon head and tail were isolated respectively, and then transformed into graphite following our previous procedure, The adduct levels were determined by a 0.6 MV compact AMS facility at the Institute of Heavy Ion Physics of Peking University. The results indicate that: (1) AA adduct number increases with the doses within 0.1-1000 μg/kg b.w. range in a log/log linear mode, except for DNA within 10-1000 μg/kg b.w. range. (2) Comparing protamine, Hb, and SA adducts with that of spermatozoon DNA (see Fig. 1), AA mainly adducts to proteins. For instance, at 1000 μg/kg b.w. dose level, spermatozoon DNA adducts only account for about 0.71%, 1.36% and 0.82% of protamine, Hb and SA adducts, respectively. (3) AA-protamine adducts, AA

  11. Analysing the Hydraulic Actuator-based Knee Unit Kinematics and Correlating the Numerical Results and Walking Human Knee Joint Behavior

    Directory of Open Access Journals (Sweden)

    K. A. Trukhanov

    2014-01-01

    Full Text Available State-of-the-art machinery development enables people with lost lower limb to continue their previous life despite a loss. International companies dealing with this area pursue a minimization of human behaviour problems because of amputation. Researches to create an optimal design of the artificial knee joint are under way.The work task was to define analytical relationships of changing kinematic parameters of the human walking on the flat surface such as an angle of the knee joint, knee point (moment, definition of reduced knee actuator (A load, as well as to compare obtained results with experimental data.As an A in created design, the article proposes to use a controlled shock absorber based on the hydraulic cylinder.A knee unit is a kinematic two-tier mechanism. One of the mechanism links performs rotational motion, and the other is rotation-translational to provide a rotation of the first one.When studying the hydraulic actuator device dynamics, as a generalized coordinate a coordinate of the piston x (or ρ position is chosen while in the study of link movements an angle β is preferable.Experimental data are obtained for a human with the body weight of 57.6 kg walking on the flat surface to estimate a value of the knee joint angle, speed, acceleration, torque, and capacity in the knee joint and are taken from the published works of foreign authors.A trigonometric approximation was used for fitting the experimental data. The resulting dependence of the reduced load on the stock of A is necessary to perform the synthesis of A. The criterion for linear mechanisms mentioned in the D.N. Popov’s work is advisable to use as a possible criterion for optimization of A.The results obtained are as follows:1. Kinematics linkage mechanism is described using relationships for dependencies of its geometrical parameters, namely a cylinder piston stroke x (or ρ and a links angle β.2. Obtained polynomials of kinematic relationships allow a synthesis of

  12. [Periprosthetic knee fractures].

    Science.gov (United States)

    Mittlmeier, T; Beck, M; Bosch, U; Wichelhaus, A

    2016-01-01

    The cumulative incidence of periprosthetic fractures around the knee is increasing further because of an extended indication for knee replacement, previous revision arthroplasty, rising life expectancy and comorbidities. The relevance of local parameters such as malalignment, osseous defects, neighbouring implants, aseptic loosening and low-grade infections may sometimes be hidden behind the manifestation of a traumatic fracture. A differentiated diagnostic approach before the treatment of a periprosthetic fracture is of paramount importance, while the physician in-charge should also have particular expertise in fracture treatment and in advanced techniques of revision endoprosthetics. The following work gives an overview of this topic. Valid classifications are available for categorising periprosthetic fractures of the femur, the tibia and the patella respectively, which are helpful for the selection of treatment. With the wide-ranging modern treatment portfolio bearing in mind the substantial rate of complications and the heterogeneous functional outcome, the adequate analysis of fracture aetiology and the corresponding transformation into an individualised treatment concept offer the chance of an acceptable functional restoration of the patient at early full weight-bearing and prolonged implant survival. The management of complications is crucial to the final outcome.

  13. Inhibition of nitrobenzene-induced DNA and hemoglobin adductions by dietary constituents

    Energy Technology Data Exchange (ETDEWEB)

    Li Hongli; Cheng Yan; Wang Haifang; Sun Hongfang; Liu Yuanfang E-mail: yliu@pku.edu.cn; Liu Kexin; Peng Shixiang

    2003-03-01

    Nitrobenzene (NB), a widely used industrial chemical, is a likely human carcinogen. Many dietary constituents can suppress the DNA-adduction, acting as the inhibitors of cancer. In this study, we investigated the inhibitory effects of vitamin C (VC), vitamin E (VE), tea polyphenols (TP), garlic squeeze, curcumin, and grapestone extract on NB-DNA and NB-hemoglobin (Hb) adductions in mice using an ultrasensitive method of accelerator mass spectrometry (AMS) with {sup 14}C-labelled nitrobenzene. All of these dietary constituents showed their inhibitory effects on DNA or Hb adduction. VC, VE, TP and grapestone extract could efficaciously inhibit the adductions by 33-50%, and all of these six agents could inhibit Hb adduction by 30-64%. We also investigated resveratrol, curcumin, VC and VE as inhibitors of NB-DNA adduction in vitro using liquid scintillation counting technique. These agents in the presence of NADPH and S9 components also pronouncedly blocked DNA adduction in a dose-dependent profile. Our study suggests that these seven constituents may interrupt the process of NB-induced chemical carcinogenesis.

  14. Microdose-Induced Drug-DNA Adducts as Biomarkers of Chemotherapy Resistance in Humans and Mice.

    Science.gov (United States)

    Zimmermann, Maike; Wang, Si-Si; Zhang, Hongyong; Lin, Tzu-Yin; Malfatti, Michael; Haack, Kurt; Ognibene, Ted; Yang, Hongyuan; Airhart, Susan; Turteltaub, Kenneth W; Cimino, George D; Tepper, Clifford G; Drakaki, Alexandra; Chamie, Karim; de Vere White, Ralph; Pan, Chong-Xian; Henderson, Paul T

    2017-02-01

    We report progress on predicting tumor response to platinum-based chemotherapy with a novel mass spectrometry approach. Fourteen bladder cancer patients were administered one diagnostic microdose each of [ 14 C]carboplatin (1% of the therapeutic dose). Carboplatin-DNA adducts were quantified by accelerator mass spectrometry in blood and tumor samples collected within 24 hours, and compared with subsequent chemotherapy response. Patients with the highest adduct levels were responders, but not all responders had high adduct levels. Four patient-derived bladder cancer xenograft mouse models were used to test the possibility that another drug in the regimen could cause a response. The mice were dosed with [ 14 C]carboplatin or [ 14 C]gemcitabine and the resulting drug-DNA adduct levels were compared with tumor response to chemotherapy. At least one of the drugs had to induce high drug-DNA adduct levels or create a synergistic increase in overall adducts to prompt a corresponding therapeutic response, demonstrating proof-of-principle for drug-DNA adducts as predictive biomarkers. Mol Cancer Ther; 16(2); 376-87. ©2016 AACR. ©2016 American Association for Cancer Research.

  15. Electrophilic properties of patulin. Adduct structures and reaction pathways with 4-bromothiophenol and other model nucleophiles.

    Science.gov (United States)

    Fliege, R; Metzler, M

    2000-05-01

    The mycotoxin patulin (PAT) is believed to exert its cytotoxic and chromosome-damaging effects by forming covalent adducts with essential cellular thiols. Since the chemical structures of such adducts are unknown to date, we have studied the reaction of PAT and its O-acetylated derivative with the monofunctional thiol model compound 4-bromothiophenol (BTP), which was chosen due to analytical advantages. By means of analytical and preparative high-performance liquid chromatography, 16 adducts of PAT and 3 adducts of acetyl-PAT were isolated and their chemical structures elucidated by (1)H and (13)C NMR, IR, and UV spectroscopy. Time course studies and analysis of daughter product formation from isolated intermediate adducts led to a detailed scheme for the reaction of PAT with BTP. The structures of adducts of PAT formed with other model nucleophiles, e. g., the aliphatic thiol 2-mercaptoethanol and the aromatic amine 4-bromoaniline, were also elucidated and found to corroborate the reaction scheme. In addition, one further reaction pathway was observed with 2-mercaptoethanol, which appears to be independent from those found for BTP. Our study with model nucleophiles provides insights into the electrophilic reactivity of PAT and proved to be useful for the structure elucidation of PAT adducts with biological nucleophiles of toxicological relevance, as will be reported by Fliege and Metzler [(2000) Chem. Res. Toxicol. 13, 373-381].

  16. Polycyclic Aromatic Hydrocarbon (PAH Exposure and DNA Adduct Semi-Quantitation in Archived Human Tissues

    Directory of Open Access Journals (Sweden)

    M. Margaret Pratt

    2011-06-01

    Full Text Available Polycyclic aromatic hydrocarbons (PAHs are combustion products of organic materials, mixtures of which contain multiple known and probable human carcinogens. PAHs occur in indoor and outdoor air, as well as in char-broiled meats and fish. Human exposure to PAHs occurs by inhalation, ingestion and topical absorption, and subsequently formed metabolites are either rendered hydrophilic and excreted, or bioactivated and bound to cellular macromolecules. The formation of PAH-DNA adducts (DNA binding products, considered a necessary step in PAH-initiated carcinogenesis, has been widely studied in experimental models and has been documented in human tissues. This review describes immunohistochemistry (IHC studies, which reveal localization of PAH-DNA adducts in human tissues, and semi-quantify PAH-DNA adduct levels using the Automated Cellular Imaging System (ACIS. These studies have shown that PAH-DNA adducts concentrate in: basal and supra-basal epithelium of the esophagus, cervix and vulva; glandular epithelium of the prostate; and cytotrophoblast cells and syncitiotrophoblast knots of the placenta. The IHC photomicrographs reveal the ubiquitous nature of PAH-DNA adduct formation in human tissues as well as PAH-DNA adduct accumulation in specific, vulnerable, cell types. This semi-quantative method for PAH-DNA adduct measurement could potentially see widespread use in molecular epidemiology studies.

  17. Moment-to-moment dynamics of ADHD behaviour

    Directory of Open Access Journals (Sweden)

    Aase Heidi

    2005-08-01

    learning long behavioural sequences may ultimately lead to deficient development of verbally governed behaviour and self control. The study represents a new approach to analyzing the moment-to-moment dynamics of behaviour, and provides support for the theory that reinforcement processes are altered in ADHD.

  18. Effect of knee joint icing on knee extension strength and knee pain early after total knee arthroplasty: a randomized cross-over study

    DEFF Research Database (Denmark)

    Holm, Bente; Husted, Henrik; Kehlet, Henrik

    2012-01-01

    Objective: To investigate the acute effect of knee joint icing on knee extension strength and knee pain in patients shortly after total knee arthroplasty.Design: A prospective, single-blinded, randomized, cross-over study.Setting: A fast-track orthopaedic arthroplasty unit at a university hospital.......Participants: Twenty patients (mean age 66 years; 10 women) scheduled for primary unilateral total knee arthroplasty.Interventions: The patients were treated on two days (day 7 and day 10) postoperatively. On one day they received 30 minutes of knee icing (active treatment) and on the other day they received 30...... minutes of elbow icing (control treatment). The order of treatments was randomized.Main outcome measures: Maximal knee extension strength (primary outcome), knee pain at rest and knee pain during the maximal knee extensions were measured 2-5 minutes before and 2-5 minutes after both treatments...

  19. Experimental knee pain reduces muscle strength

    DEFF Research Database (Denmark)

    Henriksen, Marius; Mortensen, Sara Rosager; Aaboe, Jens

    2011-01-01

    Pain is the principal symptom in knee pathologies and reduced muscle strength is a common observation among knee patients. However, the relationship between knee joint pain and muscle strength remains to be clarified. This study aimed at investigating the changes in knee muscle strength following...... experimental knee pain in healthy volunteers, and if these changes were associated with the pain intensities. In a crossover study, 18 healthy subjects were tested on 2 different days. Using an isokinetic dynamometer, maximal muscle strength in knee extension and flexion was measured at angular velocities 0....... Knee pain reduced the muscle strength by 5 to 15% compared to the control conditions (P knee extension and flexion at all angular velocities. The reduction in muscle strength was positively correlated to the pain intensity. Experimental knee pain significantly reduced knee extension...

  20. Direct antioxidant properties of methotrexate: Inhibition of malondialdehyde-acetaldehyde-protein adduct formation and superoxide scavenging

    Directory of Open Access Journals (Sweden)

    Matthew C. Zimmerman

    2017-10-01

    Full Text Available Methotrexate (MTX is an immunosuppressant commonly used for the treatment of autoimmune diseases. Recent observations have shown that patients treated with MTX also exhibit a reduced risk for the development of cardiovascular disease (CVD. Although MTX reduces systemic inflammation and tissue damage, the mechanisms by which MTX exerts these beneficial effects are not entirely known. We have previously demonstrated that protein adducts formed by the interaction of malondialdehyde (MDA and acetaldehyde (AA, known as MAA-protein adducts, are present in diseased tissues of individuals with rheumatoid arthritis (RA or CVD. In previously reported studies, MAA-adducts were shown to be highly immunogenic, supporting the concept that MAA-adducts not only serve as markers of oxidative stress but may have a direct role in the pathogenesis of inflammatory diseases. Because MAA-adducts are commonly detected in diseased tissues and are proposed to mitigate disease progression in both RA and CVD, we tested the hypothesis that MTX inhibits the generation of MAA-protein adducts by scavenging reactive oxygen species. Using a cell free system, we found that MTX reduces MAA-adduct formation by approximately 6-fold, and scavenges free radicals produced during MAA-adduct formation. Further investigation revealed that MTX directly scavenges superoxide, but not hydrogen peroxide. Additionally, using the Nrf2/ARE luciferase reporter cell line, which responds to intracellular redox changes, we observed that MTX inhibits the activation of Nrf2 in cells treated with MDA and AA. These studies define previously unrecognized mechanisms by which MTX can reduce inflammation and subsequent tissue damage, namely, scavenging free radicals, reducing oxidative stress, and inhibiting MAA-adduct formation.

  1. 7-Alkylguanine adduct levels in urine, lungs and liver of mice exposed to styrene by inhalation

    International Nuclear Information System (INIS)

    Vodicka, Pavel Erik; Linhart, Igor; Novak, Jan; Koskinen, Mikko; Vodickova, Ludmila; Hemminki, Kari

    2006-01-01

    This study describes urinary excretion of two nucleobase adducts derived from styrene 7,8-oxide (SO), i.e., 7-(2-hydroxy-1-phenylethyl)guanine (N7αG) and 7-(2-hydroxy-2-phenylethyl)guanine (N7βG), as well as a formation of N7-SO-guanine adducts in lungs and liver of two month old male NMRI mice exposed to styrene by inhalation in a 3-week subacute study. Strikingly higher excretion of both isomeric nucleobase adducts in the first day of exposure was recorded, while the daily excretion of nucleobase adducts in following time intervals reached the steady-state level at 4.32 + 1.14 and 6.91 + 1.17 pmol/animal for lower and higher styrene exposure, respectively. β-SO-guanine DNA adducts in lungs increased with exposure in a linear way (F = 13.7 for linearity and 0.17 for non-linearity, respectively), reaching at the 21st day the level of 23.0 adducts/10 8 normal nucleotides, i.e., 0.74 fmol/μg DNA of 7-alkylguanine DNA adducts for the concentration of 1500 mg/m 3 , while no 7-SO-guanine DNA adducts were detected in the liver after 21 days of inhalation exposure to both of styrene concentrations. A comparison of 7-alkylguanines excreted in urine with 7-SO-guanines in lungs (after correction for depurination and for missing α-isomers) revealed that persisting 7-SO-guanine DNA adducts in lungs account for about 0.5% of the total alkylation at N7 of guanine. The total styrene-specific 7-guanine alkylation accounts for about 1.0 x 10 -5 % of the total styrene uptake, while N1-adenine alkylation contributes to this percentage only negligibly

  2. New Generation Lockable Knee Brace

    Science.gov (United States)

    2000-01-01

    A knee brace that uses Space Shuttle propulsion technology has moved a step closer to being available to help knee injury and stroke patients and may possibly benefit patients with birth defects, spinal cord injuries, and post-polio conditions. After years of hard work, inventors at NASA's Marshall Space Flight Center (MSFC) in Huntsville, Alabama, have turned over the final design and prototype to industry partners at Horton's Orthotic Lab in Little Rock, Arkansas for further clinical testing. The device, called the Selectively Lockable Knee Brace, may mean faster, less painful rehabilitation for patients by allowing the knee to move when weight is not on the heel. Devices currently on the market lock the knee in a rigid, straight-leg position, or allow continuous free motion. The knee brace is just one example of how space technology is being used to improve the lives of people on Earth. NASA's MSFC inventors Michael Shadoan and Neill Myers are space propulsion engineers who use the same mechanisms and materials to build systems for rockets that they used to design and develop the knee brace.

  3. Physiotherapy management of knee osteoarthritis.

    Science.gov (United States)

    Page, Carolyn J; Hinman, Rana S; Bennell, Kim L

    2011-05-01

    Knee osteoarthritis (OA) is a prevalent chronic joint disease causing pain and disability. Physiotherapy, which encompasses a number of modalities, is a non-invasive treatment option in the management of OA. This review summarizes the evidence for commonly used physiotherapy interventions. There is strong evidence to show short-term beneficial effects of exercise on pain and function, although the type of exercise does not seem to influence treatment outcome. Delivery modes, including individual, group or home exercise are all effective, although therapist contact may improve benefits. Attention to improving adherence to exercise is needed to maximize outcomes in the longer-term. Knee taping applied with the aim of realigning the patella and unloading soft tissues can reduce pain. There is also evidence to support the use of knee braces in people with knee OA. Biomechanical studies show that lateral wedge shoe insoles reduce knee load but clinical trials do not support symptomatic benefits. Recent studies suggest individual shoe characteristics also affect knee load and there is current interest in the effect of modified shoe designs. Manual therapy, while not to be used as a stand-alone treatment, may be beneficial. In summary, although the research is not equivocal, there is sufficient evidence to indicate that physiotherapy interventions can reduce pain and improve function in those with knee OA. © 2011 The Authors. International Journal of Rheumatic Diseases © 2011 Asia Pacific League of Associations for Rheumatology and Blackwell Publishing Asia Pty Ltd.

  4. Ground reaction forces and knee kinetics during single and repeated badminton lunges.

    Science.gov (United States)

    Lam, Wing Kai; Ding, Rui; Qu, Yi

    2017-03-01

    Repeated movement (RM) lunge that frequently executed in badminton might be used for footwear evaluation. This study examined the influence of single movement (SM) and RM lunges on the ground reaction forces (GRFs) and knee kinetics during the braking phase of a badminton lunge step. Thirteen male university badminton players performed left-forward lunges in both SM and RM sessions. Force platform and motion capturing system were used to measure GRFs and knee kinetics variables. Paired t-test was performed to determine any significant differences between SM and RM lunges regarding mean and coefficient of variation (CV) in each variable. The kinetics results indicated that compared to SM lunges, the RM lunges had shorter contact time and generated smaller maximum loading rate of impact force, peak knee anterior-posterior force, and peak knee sagittal moment but generated larger peak horizontal resultant forces (Ps < 0.05). Additionally, the RM lunges had lower CV for peak knee medial-lateral and vertical forces (Ps < 0.05). These results suggested that the RM testing protocols had a distinct loading response and adaptation pattern during lunge and that the RM protocol showed higher within-trial reliability, which may be beneficial for the knee joint loading evaluation under different interventions.

  5. Pulse radiolysis studies of the interaction of tea polyphenol derivatives with oxidizing OH adduct of thymine

    International Nuclear Information System (INIS)

    Jiang Yue; Li Hucheng; Yao Side; Zuo Zhihua; Wang Zailan; Zhang Jiashan; Lin Nianyun

    1996-01-01

    The electron transfer reactions between oxidizing OH adduct of thymine with tea polyphenol derivatives has been investigated by pulse radiolysis. The tea polyphenol derivatives are identified as good antioxidants for reduction of oxidizing OH adducts of thymine. From buildup kinetic analysis of radical phenoxyl product, the rate constants for reactions of the N 3 radical with tea polyphenol derivatives have been determined to be (8-9) x 10 9 dm 3 /mol s, while the rate constants of electron transfer from tea polyphenol derivatives to oxidizing OH adducts of thymine was obtained to be around 10 9 dm 3 /mol s. Copyright direct C 1996 Elsevier Science Ltd

  6. DNA-nicotine adduction of lung and liver of mice exposed to passive smoking studied by AMS

    International Nuclear Information System (INIS)

    Hou Qin; Sun Hongfang; Shi Jingyuan; Liu Yuanfang; Wang Jianjun; Lu Xiangyang; Li Kun; Zhao Qiang

    1997-01-01

    The author presents the measurement of adduction of mice lung or liver DNA with nicotine by accelerator mass spectrometry (AMS). Mice were exposed in a toxicity infecting chamber filled up with cigarette smoke for a period of time of simulate the exposure of mice to passive smoking. The dose of nicotine inhaled by mice was determined. The results of AMS showed, when the dose of inhaled nicotine ranged from 33 μg/kg to 330 μg/kg, the adducts number of lung DNA was 10 3 -10 4 adducts/10 12 nucleotides, and the adducts increased linearly with increasing dose of nicotine; the adducts number of liver DNA reached to 10 4 -10 5 adducts/10 12 nucleotides, when the dose of nicotine ranged from 99 μg/kg to 330 μg/kg, and the adducts increased vigorously as dose of nicotine increased. Comparing the DNA adducts levels of the same nicotine dose, liver DNA adducts were more than lung DNA adducts. This study also suggested that the other components of cigarette smoke have synergic effect on the formation of nicotine derived DNA adducts

  7. Mobile ankle and knee perturbator.

    Science.gov (United States)

    Andersen, Jacob Buus; Sinkjaer, Thomas

    2003-10-01

    A mobile ankle and knee perturbator has been developed. It consists of a functional joint with an integrated clutch. Four Bowden wires connect the joint to a powerful motor and a double pneumatic cylinder. When needed during any time of the gait cycle, it is possible to impose an ankle rotation by engaging the clutch and rotating the ankle or knee joint with a predefined displacement. The system is designed to investigate electrophysiological and biomechanical features of the human ankle or knee joint during gait.

  8. The Critical Moment of Transition

    DEFF Research Database (Denmark)

    Svalgaard, Lotte

    2018-01-01

    By providing a holding environment to acknowledge sensitivities and address emotions, leadership programmes prove to be powerful spaces for increasing self- and social awareness. However, the challenge is for one to maintain the newly gained self- and social awareness after leaving the holding...... – within the context of an international MBA program – of MBA students applying their knowledge from a Leadership Stream in an International Consultancy Project. This paper contributes to the theory and practice of management learning by providing lenses to understand subjective experiences of critical...... moments of transition, developing the notion of “mindful avoidance,” and pointing out a major and neglected potential space in the design of management education....

  9. Evaluation and management of knee pain in young athletes: overuse injuries of the knee

    OpenAIRE

    Patel, Dilip R.; Villalobos, Ana

    2017-01-01

    Recurrent or chronic activity related knee pain is common in young athletes. Numerous intrinsic conditions affecting the knee can cause such pain. In addition, knee pain can be referred pain from low back, hip or pelvic pathology. The most common cause of knee pain in young athletes is patellofemoral pain syndrome, or more appropriately termed idiopathic anterior knee pain. Although, numerous anatomical and biomechanical factors have been postulated to contribute the knee pain in young athlet...

  10. Anterior Knee Pain (Chondromalacia Patellae).

    Science.gov (United States)

    Garrick, James G.

    1989-01-01

    This article presents a pragmatic approach to the definition, diagnosis, and management of anterior knee pain. Symptoms and treatment are described. Emphasis is on active involvement of the patient in the rehabilitation exercise program. (IAH)

  11. Unusual Cause of Knee Locking

    Directory of Open Access Journals (Sweden)

    Gazi Huri

    2013-01-01

    Full Text Available We report a case of partial intrasubstance tear of popliteus tendon as an unusual cause of pseudolocking of the knee. A 13-year-old semiprofessional soccer player applied to our clinic with a locked right knee in spite of the therapy applied (cold pack, NSAID, and immobilization in another institution 20 days after the injury. Significant extension loss was observed in his right knee with 30∘–90∘ ROM. Magnetic resonance imaging (MRI and arthroscopy confirmed the intrasubstance tear of popliteus tendon and synovitis. The ruptured part of the tendon was debrided, and the inflammatory tissue around the tendon, which may lead to pseudolocking, was gently removed with a shaver in order to regain the normal ROM. The patient was discharged with full ROM and weight bearing first day after the surgery. To our knowledge, this is the first case demonstrating intrasubstance tear of popliteus tendon causing pseudolocking of the knee.

  12. Bowlegs and Knock-Knees

    Science.gov (United States)

    ... Español Text Size Email Print Share Bowlegs and Knock-Knees Page Content Article Body Toddlers’ legs often ... about two years old, then they’ll look knock-kneed until they are about six years of ...

  13. A pneumatically powered knee-ankle-foot orthosis (KAFO with myoelectric activation and inhibition

    Directory of Open Access Journals (Sweden)

    Ferris Daniel P

    2009-06-01

    Full Text Available Abstract Background The goal of this study was to test the mechanical performance of a prototype knee-ankle-foot orthosis (KAFO powered by artificial pneumatic muscles during human walking. We had previously built a powered ankle-foot orthosis (AFO and used it effectively in studies on human motor adaptation, locomotion energetics, and gait rehabilitation. Extending the previous AFO to a KAFO presented additional challenges related to the force-length properties of the artificial pneumatic muscles and the presence of multiple antagonistic artificial pneumatic muscle pairs. Methods Three healthy males were fitted with custom KAFOs equipped with artificial pneumatic muscles to power ankle plantar flexion/dorsiflexion and knee extension/flexion. Subjects walked over ground at 1.25 m/s under four conditions without extensive practice: 1 without wearing the orthosis, 2 wearing the orthosis with artificial muscles turned off, 3 wearing the orthosis activated under direct proportional myoelectric control, and 4 wearing the orthosis activated under proportional myoelectric control with flexor inhibition produced by leg extensor muscle activation. We collected joint kinematics, ground reaction forces, electromyography, and orthosis kinetics. Results The KAFO produced ~22%–33% of the peak knee flexor moment, ~15%–33% of the peak extensor moment, ~42%–46% of the peak plantar flexor moment, and ~83%–129% of the peak dorsiflexor moment during normal walking. With flexor inhibition produced by leg extensor muscle activation, ankle (Pearson r-value = 0.74 ± 0.04 and knee ( r = 0.95 ± 0.04 joint kinematic profiles were more similar to the without orthosis condition compared to when there was no flexor inhibition (r = 0.49 ± 0.13 for ankle, p = 0.05, and r = 0.90 ± 0.03 for knee, p = 0.17. Conclusion The proportional myoelectric control with flexor inhibition allowed for a more normal gait than direct proportional myoelectric control. The current

  14. A pneumatically powered knee-ankle-foot orthosis (KAFO) with myoelectric activation and inhibition

    Science.gov (United States)

    Sawicki, Gregory S; Ferris, Daniel P

    2009-01-01

    Background The goal of this study was to test the mechanical performance of a prototype knee-ankle-foot orthosis (KAFO) powered by artificial pneumatic muscles during human walking. We had previously built a powered ankle-foot orthosis (AFO) and used it effectively in studies on human motor adaptation, locomotion energetics, and gait rehabilitation. Extending the previous AFO to a KAFO presented additional challenges related to the force-length properties of the artificial pneumatic muscles and the presence of multiple antagonistic artificial pneumatic muscle pairs. Methods Three healthy males were fitted with custom KAFOs equipped with artificial pneumatic muscles to power ankle plantar flexion/dorsiflexion and knee extension/flexion. Subjects walked over ground at 1.25 m/s under four conditions without extensive practice: 1) without wearing the orthosis, 2) wearing the orthosis with artificial muscles turned off, 3) wearing the orthosis activated under direct proportional myoelectric control, and 4) wearing the orthosis activated under proportional myoelectric control with flexor inhibition produced by leg extensor muscle activation. We collected joint kinematics, ground reaction forces, electromyography, and orthosis kinetics. Results The KAFO produced ~22%–33% of the peak knee flexor moment, ~15%–33% of the peak extensor moment, ~42%–46% of the peak plantar flexor moment, and ~83%–129% of the peak dorsiflexor moment during normal walking. With flexor inhibition produced by leg extensor muscle activation, ankle (Pearson r-value = 0.74 ± 0.04) and knee ( r = 0.95 ± 0.04) joint kinematic profiles were more similar to the without orthosis condition compared to when there was no flexor inhibition (r = 0.49 ± 0.13 for ankle, p = 0.05, and r = 0.90 ± 0.03 for knee, p = 0.17). Conclusion The proportional myoelectric control with flexor inhibition allowed for a more normal gait than direct proportional myoelectric control. The current orthosis design

  15. Second vowel formant relationship to adduction: A preliminary study

    Science.gov (United States)

    Hanrahan, Kevin G.

    The relationship between the vocal tract and the larynx in the formation of vowels has been debated for decades. Vowels were first thought to have been formed in the larynx; then later it was believed that they were formed solely in the vocal tract. In the 1960s Fant formalized this belief into the Source-Filter Theory of Vowel Formation. The theory was interpreted by voice teachers to mean that the larynx had very little to do with the formation of vowels, and this interpretation has dominated voice teaching for decades. Recent research, however, is now suggesting that the larynx and the vocal tract are interactive with each other, meaning that a change of muscular function in the larynx will create a change of resonator function in the vocal tract, and vice versa. This conclusion is drawn mainly on the work of Titze, Story, Laukkanen, et.al. They have found that a relationship exists between laryngeal function and the first vowel formant (F1). When examining research on the second vowel formant (F2), this author discovered that there may be a relationship between F2 and adduction. Therefore, based on present evidence, it was hypothesized that an elevated frequency of F2 corresponded to an increase in adduction. The hypothesis was examined by comparing the resonance output and glottal closure between vowels where F2 was elevated and vowels without modification of F2. Subjects were asked to sing [i], [a], and [u] at a medium dynamic level on D4, G#4, and D5 for the female subjects and an octave below for the male subjects, once using a "generic" version of the vowel, meaning what they considered a "nice, easy, and generic" version of the vowel to be, and then again modifying the vowel to increase the frequency of the upper harmonics. Electroglottogram, pitch, intensity, and formant data were collected and compared. An increase in the frequency of F2 corresponded to an increase in the Closed Quotient (CQ), the length of time the vocal folds are closed, in a few

  16. Development of methods to measure hemoglobin adducts by gel electrophoresis - Preliminary results

    International Nuclear Information System (INIS)

    Sun, J.D.; McBride, S.M.

    1988-01-01

    Chemical adducts formed on blood hemoglobin may be a useful biomarker for assessing human exposures to these compounds. This paper reports preliminary results in the development of methods to measure such adducts that may be generally applicable for a wide variety of chemicals. Male F344/N rats were intraperitoneally injected with 14 C-BaP dissolved in corn oil. Twenty-four hours later, the rats were sacrificed. Blood samples were collected and globin was isolated. Globin protein was then cleaved into peptide fragments using cyanogen bromide and the fragments separated using 2-dimensional gel electrophoresis. The results showed that the adducted 14 C-globin fragments migrated to different areas of the gel than did unadducted fragments. Further research is being conducted to develop methods that will allow quantitation of separated adducted globin fragments from human blood samples without the use of a radiolabel. (author)

  17. NEW THIO S2- ADDUCTS WITH ANTIMONY (III AND V HALIDE: SYNTHESIS AND INFRARED STUDY

    Directory of Open Access Journals (Sweden)

    HASSAN ALLOUCH

    2013-12-01

    Full Text Available Five new S2- adducts with SbIII and SbV halides have been synthesized and studied by infrared. Discrete structures have been suggested, the environment around the antimony being tetrahedral, trigonal bipyramidal or octahedral.

  18. Noncommutative QED and anomalous dipole moments

    International Nuclear Information System (INIS)

    Riad, I.F.; Sheikh-Jabbari, M.M.

    2000-09-01

    We study QED on noncommutative spaces, NCQED. In particular we present the detailed calculation for the noncommutative electron-photon vertex and show that the Ward identity is satisfied. We discuss that in the noncommutative case moving electron will show electric dipole effects. In addition, we work out the electric and magnetic dipole moments up to one loop level. For the magnetic moment we show that noncommutative electron has an intrinsic (spin independent) magnetic moment. (author)

  19. Electric dipole moment of diatomic molecules

    International Nuclear Information System (INIS)

    Rosato, A.

    1983-01-01

    The electric dipole moment of some diatomic molecules is calculated using the Variational Cellular Method. The results obtained for the molecules CO, HB, HF and LiH are compared with other calculations and with experimental data. It is shown that there is strong dependence of the electric dipole moment with respect to the geometry of the cells. It is discussed the possibility of fixing the geometry of the problem by giving the experimental value of the dipole moment. (Author) [pt

  20. Electric dipole moment of diatomic molecules

    International Nuclear Information System (INIS)

    Rosato, A.

    1983-01-01

    The electric dipole moment of some diatomic molecules is calculated using the Variational Cellular Method. The results obtained for the CO, HB, HF and LiH molecules are compared with other calculations and with experimental data. It is shown that there is strong dependence of the electric dipole moment with respect to the geometry of the cells. The possibility of fixing the geometry of the problem by giving the experimental value of the dipole moment is discussed. (Author) [pt

  1. Restrictions on the neutrino magnetic dipole moment

    International Nuclear Information System (INIS)

    Duncan, M.J.; Sankar, S.U.; Grifols, J.A.; Mendez, A.

    1987-01-01

    We examine mechanisms for producing neutrino magnetic moments from a wide class of particle theories which are extensions of the standard model. We show that it is difficult to naturally obtain a moment greater than ≅ 10 -2 electron Bohr magnetons. Thus models of phenomena requiring moments of order ≅ 10 -10 magnetons, such as those proposed as a resolution to the solar neutrino puzzle, are in conflict with current perceptions in particle physics. (orig.)

  2. W-boson electric dipole moment

    International Nuclear Information System (INIS)

    He, X.; McKellar, B.H.J.

    1990-01-01

    The W-boson electric dipole moment is calculated in the SU(3) C xSU(2) L xU(1) Y model with several Higgs-boson doublets. Using the constraint on the CP-violating parameters from the experimental upper bound of the neutron electric dipole moment, we find that the W-boson electric dipole moment is constrained to be less than 10 -4

  3. Forefoot strikers exhibit lower running-induced knee loading than rearfoot strikers.

    Science.gov (United States)

    Kulmala, Juha-Pekka; Avela, Janne; Pasanen, Kati; Parkkari, Jari

    2013-12-01

    Knee pain and Achilles tendinopathies are the most common complaints among runners. The differences in the running mechanics may play an important role in the pathogenesis of lower limb overuse injuries. However, the effect of a runner's foot strike pattern on the ankle and especially on the knee loading is poorly understood. The purpose of this study was to examine whether runners using a forefoot strike pattern exhibit a different lower limb loading profile than runners who use rearfoot strike pattern. Nineteen female athletes with a natural forefoot strike (FFS) pattern and pair-matched women with rearfoot strike (RFS) pattern (n = 19) underwent 3-D running analysis at 4 m·s⁻¹. Joint angles and moments, patellofemoral contact force and stresses, and Achilles tendon forces were analyzed and compared between groups. FFS demonstrated lower patellofemoral contact force and stress compared with heel strikers (4.3 ± 1.2 vs 5.1 ± 1.1 body weight, P = 0.029, and 11.1 ± 2.9 vs 13.0 ± 2.8 MPa, P = 0.04). In addition, knee frontal plane moment was lower in the FFS compared with heel strikers (1.49 ± 0.51 vs 1.97 ± 0.66 N·m·kg⁻¹, P =0.015). At the ankle level, FFS showed higher plantarflexor moment (3.12 ± 0.40 vs 2.54 ± 0.37 N·m·kg⁻¹; P = 0.001) and Achilles tendon force (6.3 ± 0.8 vs 5.1 ± 1.3 body weight; P = 0.002) compared with RFS. To our knowledge, this is the first study that shows differences in patellofemoral loading and knee frontal plane moment between FFS and RFS. FFS exhibit both lower patellofemoral stress and knee frontal plane moment than RFS, which may reduce the risk of running-related knee injuries. On the other hand, parallel increase in ankle plantarflexor and Achilles tendon loading may increase risk for ankle and foot injuries.

  4. Mass Spectrometric Characterization of Circulating Covalent Protein Adducts Derived from a Drug Acyl Glucuronide Metabolite: Multiple Albumin Adductions in Diclofenac Patients

    Science.gov (United States)

    Hammond, Thomas G.; Meng, Xiaoli; Jenkins, Rosalind E.; Maggs, James L.; Castelazo, Anahi Santoyo; Regan, Sophie L.; Bennett, Stuart N. L.; Earnshaw, Caroline J.; Aithal, Guruprasad P.; Pande, Ira; Kenna, J. Gerry; Stachulski, Andrew V.; Park, B. Kevin

    2014-01-01

    Covalent protein modifications by electrophilic acyl glucuronide (AG) metabolites are hypothetical causes of hypersensitivity reactions associated with certain carboxylate drugs. The complex rearrangements and reactivities of drug AG have been defined in great detail, and protein adducts of carboxylate drugs, such as diclofenac, have been found in liver and plasma of experimental animals and humans. However, in the absence of definitive molecular characterization, and specifically, identification of signature glycation conjugates retaining the glucuronyl and carboxyl residues, it cannot be assumed any of these adducts is derived uniquely or even fractionally from AG metabolites. We have therefore undertaken targeted mass spectrometric analyses of human serum albumin (HSA) isolated from diclofenac patients to characterize drug-derived structures and, thereby, for the first time, have deconstructed conclusively the pathways of adduct formation from a drug AG and its isomeric rearrangement products in vivo. These analyses were informed by a thorough understanding of the reactions of HSA with diclofenac AG in vitro. HSA from six patients without drug-related hypersensitivities had either a single drug-derived adduct or one of five combinations of 2–8 adducts from among seven diclofenac N-acylations and three AG glycations on seven of the protein’s 59 lysines. Only acylations were found in every patient. We present evidence that HSA modifications by diclofenac in vivo are complicated and variable, that at least a fraction of these modifications are derived from the drug’s AG metabolite, and that albumin adduction is not inevitably a causation of hypersensitivity to carboxylate drugs or a coincidental association. PMID:24902585

  5. Value of knee joint arthrography

    International Nuclear Information System (INIS)

    Luzsa, Gyoergy; Kiss Toth, Peter

    1985-01-01

    On the basis of the literature and the analysis of 204 examinations, the method and clinical application of knee joint arthrography are reviewed. 50 out of the 54 operated cases were perfectly diagnosed. The double contrast knee joint arthrography can be applied to detect meniscus changes, popliteal cysts, synovial disorders and chondral defects. The effectiveness of arthrography and arthroscopy was compared and the introduction of the former in each county seat is suggested. (author)

  6. Does post-operative knee awareness differ between knees in bilateral simultaneous total knee arthroplasty? Predictors of high or low knee awareness

    DEFF Research Database (Denmark)

    Nielsen, Katrine Abildgaard; Thomsen, Morten Grove; Latifi, Roshan

    2016-01-01

    PURPOSE: To evaluate the difference in post-operative knee awareness between knees in patients undergoing bilateral simultaneous total knee arthroplasty (TKA) and to assess factors predicting high or low knee awareness. METHODS: This study was conducted on 99 bilateral simultaneous TKAs performed...... at our institution from 2008 to 2012. All patients received one set of questionnaires [Forgotten Joint Score (FJS) and Oxford Knee Score (OKS)] for each knee. Based on the FJS, the patients' knees were divided into two groups: "best" and "worst" knees. The median of the absolute difference in FJS and OKS...... within each patient was calculated. Multivariate linear regression was performed to identify factors affecting FJS. RESULTS: The difference between knees was 1 point (CI 0-5) for the FJS and 1 point (CI 0-2) for the OKS. The FJS for females increased (decreasing awareness) with increasing age. Males had...

  7. How to introduce the magnetic dipole moment

    International Nuclear Information System (INIS)

    Bezerra, M; Kort-Kamp, W J M; Cougo-Pinto, M V; Farina, C

    2012-01-01

    We show how the concept of the magnetic dipole moment can be introduced in the same way as the concept of the electric dipole moment in introductory courses on electromagnetism. Considering a localized steady current distribution, we make a Taylor expansion directly in the Biot-Savart law to obtain, explicitly, the dominant contribution of the magnetic field at distant points, identifying the magnetic dipole moment of the distribution. We also present a simple but general demonstration of the torque exerted by a uniform magnetic field on a current loop of general form, not necessarily planar. For pedagogical reasons we start by reviewing briefly the concept of the electric dipole moment. (paper)

  8. Gross shell structure of moments of inertia

    International Nuclear Information System (INIS)

    Deleplanque, M.A.; Frauendorf, S.; Pashkevich, V.V.; Chu, S.Y.; Unzhakova, A.

    2002-01-01

    Average yrast moments of inertia at high spins, where the pairing correlations are expected to be largely absent, were found to deviate from the rigid-body values. This indicates that shell effects contribute to the moment of inertia. We discuss the gross dependence of moments of inertia and shell energies on the neutron number in terms of the semiclassical periodic orbit theory. We show that the ground-state shell energies, nuclear deformations and deviations from rigid-body moments of inertia are all due to the same periodic orbits

  9. Analysis of scaled-factorial-moment data

    International Nuclear Information System (INIS)

    Seibert, D.

    1990-01-01

    We discuss the two standard constructions used in the search for intermittency, the exclusive and inclusive scaled factorial moments. We propose the use of a new scaled factorial moment that reduces to the exclusive moment in the appropriate limit and is free of undesirable multiplicity correlations that are contained in the inclusive moment. We show that there are some similarities among most of the models that have been proposed to explain factorial-moment data, and that these similarities can be used to increase the efficiency of testing these models. We begin by calculating factorial moments from a simple independent-cluster model that assumes only approximate boost invariance of the cluster rapidity distribution and an approximate relation among the moments of the cluster multiplicity distribution. We find two scaling laws that are essentially model independent. The first scaling law relates the moments to each other with a simple formula, indicating that the different factorial moments are not independent. The second scaling law relates samples with different rapidity densities. We find evidence for much larger clusters in heavy-ion data than in light-ion data, indicating possible spatial intermittency in the heavy-ion events

  10. DNA adduct formation among workers in a Thai industrial estate and nearby residents.

    Science.gov (United States)

    Peluso, Marco; Srivatanakul, Petcharin; Munnia, Armelle; Jedpiyawongse, Adisorn; Meunier, Aurelie; Sangrajrang, Suleeporn; Piro, Sara; Ceppi, Marcello; Boffetta, Paolo

    2008-01-25

    The genotoxic effects of air pollutant exposures have been studied in people living and working in Map Ta Phut, Rayong province, Thailand, a site where is located the Map Ta Phut Industrial Estate (MIE) one of the largest steel, refinery and petrochemical complex in the South-Eastern Asia. This was done by the conduction of a transversal study aimed to compare the prevalence of bulky DNA adducts in groups of subjects experiencing various degree of air pollution. DNA adduct analysis was performed in the leukocytes of 201 volunteers by the (32)P-postlabelling assay: 79 were workers in the MIE complex, including 24 refinery workers, 40 steel workers and 15 tinplate workers, 72 were people residing downwind in the MIE area and 50 were residents in a control district of the same Rayong province but without industrial exposures. The groups of workers were analyzed separately to evaluate if DNA adduct formation differs by the type of industry. The levels of bulky DNA adducts were 1.17+/-0.17 (SE) adducts/10(8) nucleotides in refinery workers, 1.19+/-0.19 (SE) in steel workers, 0.87+/-0.17 (SE) in tinplate workers, 0.85+/-0.07 (SE) in MIE residents and 0.53+/-0.05 (SE) in district controls. No effects of smoking habits on DNA adducts was found. The multivariate regression analysis shows that the levels of DNA adducts were significantly increased among the individuals living near the MIE industrial complex in respect to those resident in a control district (pindustrial air pollution can experiment an excess of DNA adduct formation. The emissions from the MIE complex are the main source of air pollution in this area and can be the cause of such increment in the levels of DNA damage.

  11. Amino acid-based dithiazines: synthesis and photofragmentation of their benzaldehyde adducts.

    Science.gov (United States)

    Kurchan, Alexei N; Kutateladze, Andrei G

    2002-11-14

    Alpha-amino acids and GABA are functionalized with dithiazine rings via reaction with sodium hydrosulfide in aqueous formaldehyde. The resulting dithiazines are lithiated at -78 degrees C and reacted with benzaldehyde furnishing amino acid-based 2,5-bis-substituted dithiazines. These adducts undergo externally sensitized photofragmentation with quantum efficiency comparable to that of the parent dithiane adducts, thus offering a novel approach to amino acid-based photolabile tethers. [reaction: see text

  12. Structure and Oxidation of Pyrrole Adducts Formed between Aflatoxin B2a and Biological Amines.

    Science.gov (United States)

    Rushing, Blake R; Selim, Mustafa I

    2017-06-19

    Aflatoxin B 2a has been shown to bind to proteins through a dialdehyde intermediate under physiological conditions. The proposed structure of this adduct has been published showing a Schiff base interaction, but adequate verification using structural elucidation instrumental techniques has not been performed. In this work, we synthesized the aflatoxin B 2a amino acid adduct under alkaline conditions, and the formation of a new product was determined using high performance liquid chromatography-time-of-flight mass spectrometry. The resulting accurate mass was used to generate a novel proposed chemical structure of the adduct in which the dialdehyde forms a pyrrole ring with primary amines rather than the previously proposed Schiff base interaction. The pyrrole structure was confirmed using 1 H, 13 C, correlation spectroscopy, heteronuclear single quantum correlation, and heteronuclear multiple bond correlation NMR and tandem mass spectrometry. Reaction kinetics show that the reaction is overall second order and that the rate increases as pH increases. Additionally, this study shows for the first time that aflatoxin B 2a dialdehyde forms adducts with phosphatidylethanolamines and does so through pyrrole ring formation, which makes it the first aflatoxin-lipid adduct to be structurally identified. Furthermore, oxidation of the pyrrole adduct produced a product that was 16 m/z heavier. When the aflatoxin B 2a -lysine (ε) adduct was oxidized, it gave a product with an accurate mass, mass fragmentation pattern, and 1 H NMR spectrum that match aflatoxin B 1 -lysine, which suggest the transformation of the pyrrole ring to a pyrrolin-2-one ring. These data give new insight into the fate and chemical properties of biological adducts formed from aflatoxin B 2a as well as possible interferences with known aflatoxin B 1 exposure biomarkers.

  13. ACL Injury Prevention Training Results in Modification of Hip and Knee Mechanics During a Drop-Landing Task.

    Science.gov (United States)

    Pollard, Christine D; Sigward, Susan M; Powers, Christopher M

    2017-09-01

    Injury prevention training has been shown to be effective in reducing the incidence of noncontact anterior cruciate ligament (ACL) injury; however, the underlying reason for the success of these training programs is unclear. To investigate whether an ACL injury prevention program that has been shown to reduce the incidence of ACL injury alters sagittal plane hip and knee biomechanics during a drop-landing task. Descriptive laboratory study. Thirty female club soccer players (age range, 11-17 years) with no history of knee injury participated in this study. Kinematics and ground-reaction forces were collected while each participant performed a drop-landing task prior to and immediately after participation in a 12-week ACL injury prevention training program. After ACL injury prevention training, participants demonstrated decreased knee extensor moments ( P = .03), increased energy absorption at the hip ( P = .04), decreased knee-to-hip extensor moment ratios ( P = .05), and decreased knee-to-hip energy absorption ratios ( P = .03). Participation in an ACL injury prevention training program decreased reliance on the knee extensor muscles and improved use of the hip extensor muscles, which may explain the protective effect of this type of training program on ACL injury. Based on these findings, clinicians can better understand how ACL injury prevention training, such as the Prevent Injury and Enhance Performance (PEP) Program, may change movement behavior at both the hip and knee. Furthermore, the study findings may support the implementation of the PEP Program, or a similar program, for clinicians aiming to improve use of the hip in an effort to reduce knee loading and consequent injuries.

  14. Chemistry and Chemical Equilibrium Dynamics of BMAA and Its Carbamate Adducts.

    Science.gov (United States)

    Diaz-Parga, Pedro; Goto, Joy J; Krishnan, V V

    2018-01-01

    Beta-N-methylamino-L-alanine (BMAA) has been demonstrated to contribute to the onset of the ALS/Parkinsonism-dementia complex (ALS/PDC) and is implicated in the progression of other neurodegenerative diseases. While the role of BMAA in these diseases is still debated, one of the suggested mechanisms involves the activation of excitatory glutamate receptors. In particular, the excitatory effects of BMAA are shown to be dependent on the presence of bicarbonate ions, which in turn forms carbamate adducts in physiological conditions. The formation of carbamate adducts from BMAA and bicarbonate is similar to the formation of carbamate adducts from non-proteinogenic amino acids. Structural, chemical, and biological information related to non-proteinogenic amino acids provide insight into the formation of and possible neurological action of BMAA. This article reviews the carbamate formation of BMAA in the presence of bicarbonate ions, with a particular focus on how the chemical equilibrium of BMAA carbamate adducts may affect the molecular mechanism of its function. Highlights of nuclear magnetic resonance (NMR)-based studies on the equilibrium process between free BMAA and its adducts are presented. The role of divalent metals on the equilibrium process is also explored. The formation and the equilibrium process of carbamate adducts of BMAA may answer questions on their neuroactive potency and provide strong motivation for further investigations into other toxic mechanisms.

  15. DNA adduct quantification in Eisenia fetida after subchronic exposures to creosote contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Charrois, J.W.A.; McGill, W.B. [Alberta Univ., Dept. of Renewable Resources, Edmonton, AB (Canada)

    1999-07-01

    Within soil ecosystems contaminant toxicity can vary from acute and chronic, depending on the time of exposure. Due to the long times involved chronic toxicity is difficult to determine. DNA adducts fall into the category of biochemical markers that act as an early warning system in environmental monitoring. It has been proposed that they could be used as a sensitive method to determine environmental exposures to compounds such as polycyclic aromatic hydrocarbons (PAHs), which can occur, although not exclusively, in creosote. In this connection, Benzo[a]pyrene (BaP) is a PAH that can be transformed into an electrophilic metabolite, which ultimately results in DNA adduct formation. Use was made of a 32P postlabeling method to quantify the number of DNA adducts occurring in the earthworm Eisenia fetida after exposure to weathered creosote contaminated- and biotreated-soils with and without additions of extra BaP. DNA adducts can be measured in earthworms exposed to creosote contaminated- and biotreated-soils. E. fetida exposed to weathered creosote contaminated soils had significantly more DNA adducts than those exposed to a pristine control soil. Exposures to creosote contaminated soils with additional BaP (1000 mg/kg) or biotreatment did not yield statistically significant increases in DNA adducts compared to the pristine control. (Abstract only)

  16. Single d(ApG)/cis-diamminedichloroplatinum(II) adduct-induced mutagenesis in Escherichia coli

    International Nuclear Information System (INIS)

    Burnouf, D.; Fuchs, R.P.P.; Gauthier, C.; Chottard, J.C.

    1990-01-01

    The mutation spectrum induced by the widely used antitumor drug cis-diamminedichloroplatinum(II) (cis-DDP) showed that cisDDP[d(ApG)] adducts, although they account for only 25% of the lesions formed are ∼5 times more mutagenic than the major GG adduct. The authors report the construction of vectors bearing a single cisDDP[d(ApG)] lesion and their use in mutagenesis experiments in Escherichia coli. The mutagenic processing of the lesion is found to depend strictly on induction of the SOS system of the bacterial host cells. In SOS-induced cells, mutation frequencies of 1-2% were detected. All these mutations are targeted to the 5' base of the adduct. Single A → T transversions are mainly observed (80%), whereas A → G transitions account for 10% of the total mutations. Tandem base-pair substitutions involving the adenine residue and the thymine residue immediately 5' to the adduct occur at a comparable frequency (10%). No selective loss of the strand bearing the platinum adduct was seen, suggesting that, in vivo, cisDDP[d(ApG)] adducts are not blocking lesions. The high mutation specificity of cisDDP-[d(ApG)]-induced mutagenesis is discussed in relation to structural data

  17. Scavenging of Toxic Acrolein by Resveratrol and Hesperetin and Identification of Adducts.

    Science.gov (United States)

    Wang, Weixin; Qi, Yajing; Rocca, James R; Sarnoski, Paul J; Jia, Aiqun; Gu, Liwei

    2015-11-04

    The objective of this study was to investigate the ability of resveratrol and hesperetin to scavenge acrolein at pH 7.4 and 37 °C. About 6.4 or 5.2% of acrolein remained after reaction with resveratrol or hesperetin for 12 h at equimolar concentrations. An acrolein-resveratrol adduct and two acrolein-hesperetin adducts were isolated. Their structures were elucidated using mass and NMR spectroscopy. Acrolein reacted with resveratrol at the C-2 and C-3 positions through nucleophilic addition and formed an additional heterocyclic ring. Two similar monoacrolein-conjugated adducts were identified for hesperetin. Spectroscopic data suggested each acrolein-hesperetin adduct was a mixture of four stereoisomers due to the existence of two chiral carbon atoms. Yield of adducts was low at pH 5.4 but increased at pH 7.4 and 8.4. Higher pH also promoted the formation of diacrolein adducts. Results suggest that resveratrol and hesperetin exert health benefits in part through neutralizing toxic acrolein in vivo.

  18. DNA adduct profiling of in vitro colonic meat digests to map red vs. white meat genotoxicity.

    Science.gov (United States)

    Hemeryck, Lieselot Y; Rombouts, Caroline; De Paepe, Ellen; Vanhaecke, Lynn

    2018-05-01

    The consumption of red meat has been linked to an increased colorectal cancer (CRC) risk. One of the major hypotheses states that heme iron (present in red meat) stimulates the formation of genotoxic N-nitroso compounds (NOCs) and lipid peroxidation products (LPOs). By means of DNA adductomics, chemically induced DNA adduct formation can be mapped in relation to e.g. dietary exposures. In this study, this state-of-the-art methodology was used to investigate alkylation and (lipid per)oxidation induced DNA adduct formation in in vitro red vs. white meat digests. In doing so, 90 alkylation and (lipid per)oxidation induced DNA adduct types could be (tentatively) identified. Overall, 12 NOC- and/or LPO-related DNA adduct types, i.e. dimethyl-T (or ethyl-T), hydroxymethyl-T, tetramethyl-T, methylguanine (MeG), guanidinohydantoin, hydroxybutyl-C, hydroxymethylhydantoin, malondialdehyde-x3-C, O 6 -carboxymethylguanine, hydroxyethyl-T, carboxyethyl-T and 3,N 4 -etheno-C were singled out as potential heme-rich meat digestion markers. The retrieval of these DNA adduct markers is in support of the heme, NOC and LPO hypotheses, suggesting that DNA adduct formation may indeed contribute to red meat related CRC risk. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Capturing Labile Sulfenamide and Sulfinamide Serum Albumin Adducts of Carcinogenic Arylamines by Chemical Oxidation

    Science.gov (United States)

    Peng, Lijuan; Turesky, Robert J.

    2013-01-01

    Aromatic amines and heterocyclic aromatic amines (HAAs) are a class of structurally related carcinogens that are formed during the combustion of tobacco or during the high temperature cooking of meats. These procarcinogens undergo metabolic activation by N-oxidation of the exocyclic amine group to produce N-hydroxylated metabolites, which are critical intermediates implicated in toxicity and DNA damage. The arylhydroxylamines and their oxidized arylnitroso derivatives can also react with cysteine (Cys) residues of glutathione or proteins to form, respectively, sulfenamide and sulfinamide adducts. However, sulfur-nitrogen linked adducted proteins are often difficult to detect because they are unstable and undergo hydrolysis during proteolytic digestion. Synthetic N-oxidized intermediates of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), a carcinogenic HAA produced in cooked meats, and 4-aminobiphenyl, a carcinogenic aromatic amine present in tobacco smoke were reacted with human serum albumin (SA) and formed labile sulfenamide or sulfinamide adducts at the Cys34 residue. Oxidation of the carcinogen-modified SA with m-chloroperoxybenzoic acid (m-CPBA) produced the arylsulfonamide adducts, which were stable to heat and the chemical reduction conditions employed to denature SA. The sulfonamide adducts of PhIP and 4-ABP were identified, by liquid chromatography/mass spectrometry, in proteolytic digests of denatured SA. Thus, selective oxidation of arylamine-modified SA produces stable arylsulfonamide-SA adducts, which may serve as biomarkers of these tobacco and dietary carcinogens. PMID:23240913

  20. A fluorescent-based HPLC assay for quantification of cysteine and cysteamine adducts in Escherichia coli-derived proteins.

    Science.gov (United States)

    Soriano, Brian D; Tam, Lei-Ting T; Lu, Hsieng S; Valladares, Violeta G

    2012-01-01

    Recombinant proteins expressed in Escherichia coli are often produced as unfolded, inactive forms accumulated in inclusion bodies. Redox-coupled thiols are typically employed in the refolding process in order to catalyze the formation of correct disulfide bonds at maximal folding efficiency. These thiols and the recombinant proteins can form mixed disulfide bonds to generate thiol-protein adducts. In this work, we apply a fluorescent-based assay for the quantification of cysteine and cysteamine adducts as observed in E. coli-derived proteins. The thiols are released by reduction of the adducted protein, collected and labeled with a fluorescent reagent, 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate. The derivatized thiols are separated by reversed-phase HPLC and can be accurately quantified after method optimization. The estimated thiol content represents total amount of adducted forms present in the analyzed samples. The limit of quantification (LOQ) was established; specifically, the lowest amount of quantifiable cysteine adduction is 30 picograms and the lowest amount of quantifiable cysteamine adduction is 60 picograms. The assay is useful for quantification of adducts in final purified products as well as in-process samples from various purification steps. The assay indicates that the purification process accomplishes a decrease in cysteine adduction from 0.19 nmol adduct/nmol protein to 0.03 nmol adduct/nmol protein as well as a decrease in cysteamine adduction from 0.24 nmol adduct/nmol protein to 0.14 nmol adduct/nmol protein. Copyright © 2011. Published by Elsevier B.V.

  1. The neutron electric dipole moment

    International Nuclear Information System (INIS)

    He, X.G.; McKellar, B.H.J.; Pakvasa, S.

    1989-01-01

    A systematic study was made of the electric dipole moment (EDM) of neutron D n in various models of CP violation. It was found that in the standard KM model with 3 families the neutron EDM is in the range 1.4x10 -33 ≤ D n ≤ 1.6x10 -31 ecm; that the two Higgs doublet model has approximately the same value of D n as the standard model; that D n in the Weinberg model is predicted to satisfy D n > 10 -25 ecm; that in a class of left-right symmetric models D n is of the order of 10 -26-11 ecm; that in supersymmetric models D n is of the order 10 -22 φ ecm with φ being the possible phase difference of the phases of gluino mass and the gluino-quark-smark mixing matrix and that the strong CP parameter θ is found to be θ -9 , using the present experimental limit that D n -25 ecm with 90% confidence. 65 refs., 10 figs

  2. Kant’s Machiavellian Moment

    Directory of Open Access Journals (Sweden)

    Jay Foster

    2015-11-01

    Full Text Available At least two recent collections of essays – Postmodernism and the Enlightenment (2001 and What’s Left of Enlightenment?: A Postmodern Question (2001 – have responded to postmodern critiques of Enlightenment by arguing that Enlightenment philosophes themselves embraced a number of post-modern themes. This essay situates Kant’s essay Was ist Aufklärung (1784 in the context of this recent literature about the appropriate characterization of modernity and the Enlightenment. Adopting an internalist reading of Kant’s Aufklärung essay, this paper observes that Kant is surprisingly ambivalent about who might be Enlightened and unspecific about when Enlightenment might be achieved. The paper argues that this is because Kant is concerned less with elucidating his concept of Enlightenment and more with characterizing a political condition that might provide the conditions for the possibility of Enlightenment. This paper calls this political condition modernity and it is achieved when civil order can be maintained alongside fractious and possibly insoluble public disagreement about matters of conscience, including the nature and possibility of Enlightenment. Thus, the audience for the Aufklärung essay is not the tax collector, soldier or clergyman, but rather the sovereign. Kant enjoins and advises the prince that discord and debate about matters of conscience need not entail any political unrest or upheaval. It is in this restricted (Pocockian sense that the Enlightenment essay is Kant’s Machiavellian moment.

  3. Stereo Correspondence Using Moment Invariants

    Science.gov (United States)

    Premaratne, Prashan; Safaei, Farzad

    Autonomous navigation is seen as a vital tool in harnessing the enormous potential of Unmanned Aerial Vehicles (UAV) and small robotic vehicles for both military and civilian use. Even though, laser based scanning solutions for Simultaneous Location And Mapping (SLAM) is considered as the most reliable for depth estimation, they are not feasible for use in UAV and land-based small vehicles due to their physical size and weight. Stereovision is considered as the best approach for any autonomous navigation solution as stereo rigs are considered to be lightweight and inexpensive. However, stereoscopy which estimates the depth information through pairs of stereo images can still be computationally expensive and unreliable. This is mainly due to some of the algorithms used in successful stereovision solutions require high computational requirements that cannot be met by small robotic vehicles. In our research, we implement a feature-based stereovision solution using moment invariants as a metric to find corresponding regions in image pairs that will reduce the computational complexity and improve the accuracy of the disparity measures that will be significant for the use in UAVs and in small robotic vehicles.

  4. Closed forms and multi-moment maps

    DEFF Research Database (Denmark)

    Madsen, Thomas Bruun; Swann, Andrew Francis

    2013-01-01

    We extend the notion of multi-moment map to geometries defined by closed forms of arbitrary degree. We give fundamental existence and uniqueness results and discuss a number of essential examples, including geometries related to special holonomy. For forms of degree four, multi-moment maps are gu...

  5. Magnetic moment of single layer graphene rings

    Science.gov (United States)

    Margulis, V. A.; Karpunin, V. V.; Mironova, K. I.

    2018-01-01

    Magnetic moment of single layer graphene rings is investigated. An analytical expression for the magnetic moment as a function of the magnetic field flux through the one-dimensional quantum rings is obtained. This expression has the oscillation character. The oscillation period is equal to one flux quanta.

  6. 6-quark contribution to nuclear magnetic moments

    International Nuclear Information System (INIS)

    Ito, H.

    1985-01-01

    The magnetic moments of nuclei with LS closed shell +/-1 particle are calculated. Core polarization and meson exchange current are treated realistically in order to single out the 6-quark contribution. Overall agreement with experimental values is quite good. It is shown that the 6-quark system contributes to the respective iso-vector and iso-scalar moments with reasonable magnitudes

  7. D-dimensional moments of inertia

    International Nuclear Information System (INIS)

    Bender, C.M.; Mead, L.R.

    1995-01-01

    We calculate the moments of inertia of D-dimensional spheres and spherical shells, where D is a complex number. We also examine the moments of inertia of fractional-dimensional geometrical objects such as the Cantor set and the Sierpinski carpet and their D-dimensional analogs. copyright 1995 American Association of Physics Teachers

  8. Dynamical moments of inertia for superdeformed nuclei

    International Nuclear Information System (INIS)

    Obikhod, T.V.

    1995-01-01

    The method of quantum groups has been applied for calculation the dynamical moments of inertia for the yrast superdeformed bands in 194 Hg and 192 Hg as well as to calculation of the dynamical moments of inertia of superdeformed bands in 150 Gd and 148 Gd

  9. Polarization electric dipole moment in nonaxial nuclei

    International Nuclear Information System (INIS)

    Denisov, V.Yu.; Davidovskaya, O.I.

    1996-01-01

    An expression for the macroscopic polarization electric dipole moment is obtained for nonaxial nuclei whose radii of the proton and neutron surfaces are related by a linear equation. Dipole transitions associated with the polarization electric dipole moment are analyzed for static and dynamical multipole deformations

  10. Droplet-model electric dipole moments

    International Nuclear Information System (INIS)

    Myers, W.D.; Swiatecki, W.J.

    1991-01-01

    Denisov's recent criticism of the droplet-model formula for the dipole moment of a deformed nucleus as derived by Dorso et al., it shown to be invalid. This helps to clarify the relation of theory to the measured dipole moments, as discussed in the review article by Aberg et al. (orig.)

  11. Teachable Moment: Google Earth Takes Us There

    Science.gov (United States)

    Williams, Ann; Davinroy, Thomas C.

    2015-01-01

    In the current educational climate, where clearly articulated learning objectives are required, it is clear that the spontaneous teachable moment still has its place. Authors Ann Williams and Thomas Davinroy think that instructors from almost any discipline can employ Google Earth as a tool to take advantage of teachable moments through the…

  12. DNA adduct formation among workers in a Thai industrial estate and nearby residents

    International Nuclear Information System (INIS)

    Peluso, Marco; Srivatanakul, Petcharin; Munnia, Armelle; Jedpiyawongse, Adisorn; Meunier, Aurelie; Sangrajrang, Suleeporn; Piro, Sara; Ceppi, Marcello; Boffetta, Paolo

    2008-01-01

    The genotoxic effects of air pollutant exposures have been studied in people living and working in Map Ta Phut, Rayong province, Thailand, a site where is located the Map Ta Phut Industrial Estate (MIE) one of the largest steel, refinery and petrochemical complex in the South-Eastern Asia. This was done by the conduction of a transversal study aimed to compare the prevalence of bulky DNA adducts in groups of subjects experiencing various degree of air pollution. DNA adduct analysis was performed in the leukocytes of 201 volunteers by the 32 P-postlabelling assay: 79 were workers in the MIE complex, including 24 refinery workers, 40 steel workers and 15 tinplate workers, 72 were people residing downwind in the MIE area and 50 were residents in a control district of the same Rayong province but without industrial exposures. The groups of workers were analyzed separately to evaluate if DNA adduct formation differs by the type of industry. The levels of bulky DNA adducts were 1.17 ± 0.17 (SE) adducts/10 8 nucleotides in refinery workers, 1.19 ± 0.19 (SE) in steel workers, 0.87 ± 0.17 (SE) in tinplate workers, 0.85 ± 0.07 (SE) in MIE residents and 0.53 ± 0.05 (SE) in district controls. No effects of smoking habits on DNA adducts was found. The multivariate regression analysis shows that the levels of DNA adducts were significantly increased among the individuals living near the MIE industrial complex in respect to those resident in a control district (p < 0.05). In the groups of occupationally exposed workers, the highest levels of DNA adducts were found among the workers experiencing an occupational exposure to polycyclic aromatic hydrocarbons, e.g. the steel factory and refinery workers. When we have evaluated if the levels of DNA adducts of the PAH exposed workers were different from those of the MIE residents, a statistical significantly difference was found (p < 0.05). Our present study indicates that people living near point sources of industrial air

  13. Effect of isometric quadriceps exercise on muscle strength, pain, and function in patients with knee osteoarthritis: a randomized controlled study.

    Science.gov (United States)

    Anwer, Shahnawaz; Alghadir, Ahmad

    2014-05-01

    [Purpose] The aim of present study was to investigate the effects of isometric quadriceps exercise on muscle strength, pain, and function in knee osteoarthritis. [Subjects and Methods] Outpatients (N=42, 21 per group; age range 40-65 years; 13 men and 29 women) with osteoarthritis of the knee participated in the study. The experimental group performed isometric exercises including isometric quadriceps, straight leg raising, and isometric hip adduction exercise 5 days a week for 5 weeks, whereas the control group did not performed any exercise program. The outcome measures or dependent variables selected for this study were pain intensity, isometric quadriceps strength, and knee function. These variables were measured using the Numerical Rating Scale (NRS), strength gauge device, and reduced WOMAC index, respectively. All the measurements were taken at baseline (week 0) and at the end of the trial at week 5. [Results] In between-group comparisons, the maximum isometric quadriceps strength, reduction in pain intensity, and improvement in function in the isometric exercise group at the end of the 5th week were significantly greater than those of the control group (pisometric quadriceps exercise program showed beneficial effects on quadriceps muscle strength, pain, and functional disability in patients with osteoarthritis of the knee.

  14. Effects of thiourea and ammonium bicarbonate on the formation and stability of bifunctional cisplatin-DNA adducts : consequences for the accurate quantification of adducts in (cellular) DNA

    NARCIS (Netherlands)

    Fichtinger-Schepman, A.M.J.; Dijk-Knijnenburg, H.C.M. van; Dijt, F.J.; Velde-Visser, S.D. van der; Berends, F.; Baan, R.A.

    1995-01-01

    Cisplatin reacts with DNA by forming mainly bifunctional adducts via reactive monofunctional intermediates. When freshly platinated DNA was postincubated with thiourea (10 mM, at 23 or 37°C) for periods of up to 24 h, followed by determination of mono- and diadducts, a rapid initial decrease was

  15. Revisiting the stability of endo/exo Diels-Alder adducts between cyclopentadiene and 1,4-benzoquinone

    International Nuclear Information System (INIS)

    Tormena, Claudio F.; Lacerda Junior, Valdemar; Oliveira, Kleber T. de

    2010-01-01

    In this work it is presented a detailed theoretical analysis of the relative stability of endo/exo Diels-Alder adducts formed by the reaction between cyclopentadiene (1) and 1,4-benzoquinone (2). The intrinsic reaction coordinate (IRC) showed the existence of only one transition state for the reaction studied, for both endo 3 and exo 4 adducts. The energies of both adducts were obtained at high level of theory (CBS-Q) confirming that the endo adduct is more stable than exo, which is in the opposite way to the observed in reactions that usually follow Alder's rule. An electronic structure analysis was performed through NBO methodology, indicating that the attractive delocalization interaction predominates over the steric repulsive interaction in the endo adducts. In summary, for the studied cycloaddition reaction the endo adduct is the thermodynamic and kinetic product, which can be also confirmed by experimental data mentioned in this work. (author)

  16. Revisiting the stability of endo/exo Diels-Alder adducts between cyclopentadiene and 1,4-benzoquinone

    Energy Technology Data Exchange (ETDEWEB)

    Tormena, Claudio F. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Quimica. Dept. de Quimica Organica; Lacerda Junior, Valdemar [Universidade Federal do Espirito Santo (UFES), Vitoria, ES (Brazil). Centro de Ciencias Exatas. Dept. de Quimica; Oliveira, Kleber T. de [Universidade Federal do ABC (UFABC), Santo Andre, SP (Brazil). Centro de Ciencias Naturais e Humanas

    2010-07-01

    In this work it is presented a detailed theoretical analysis of the relative stability of endo/exo Diels-Alder adducts formed by the reaction between cyclopentadiene (1) and 1,4-benzoquinone (2). The intrinsic reaction coordinate (IRC) showed the existence of only one transition state for the reaction studied, for both endo 3 and exo 4 adducts. The energies of both adducts were obtained at high level of theory (CBS-Q) confirming that the endo adduct is more stable than exo, which is in the opposite way to the observed in reactions that usually follow Alder's rule. An electronic structure analysis was performed through NBO methodology, indicating that the attractive delocalization interaction predominates over the steric repulsive interaction in the endo adducts. In summary, for the studied cycloaddition reaction the endo adduct is the thermodynamic and kinetic product, which can be also confirmed by experimental data mentioned in this work. (author)

  17. Analysis of hemoglobin adducts from acrylamide, glycidamide, and ethylene oxide in paired mother/cord blood samples from Denmark

    DEFF Research Database (Denmark)

    von Stedingk, Hans; Vikström, Anna C; Rydberg, Per

    2011-01-01

    The knowledge about fetal exposure to acrylamide/glycidamide from the maternal exposure through food is limited. Acrylamide, glycidamide, and ethylene oxide are electrophiles and form adducts with hemoglobin (Hb), which could be used for in vivo dose measurement. In this study, a method.......20-0.73) for glycidamide, and 0.43 (range 0.17-1.34) for ethylene oxide. In vitro studies with acrylamide and glycidamide showed a lower (0.38-0.48) rate of adduct formation with Hb in cord blood than with Hb in maternal blood, which is compatible with the structural differences in fetal and adult Hb. Together...... for analysis of Hb adducts by liquid chromatography-mass spectrometry, the adduct FIRE procedure, was applied to measurements of adducts from these compounds in maternal blood samples (n = 87) and umbilical cord blood samples (n = 219). The adduct levels from the three compounds, acrylamide, glycidamide...

  18. Active knee joint flexibility and sports activity

    DEFF Research Database (Denmark)

    Hahn, Thomas; Foldspang, Anders; Vestergaard, E

    1999-01-01

    was significantly higher in women than in men and significantly positively associated with weekly hours of swimming and weekly hours of competitive gymnastics. Active knee flexion was significantly positively associated with participation in basketball, and significantly negatively associated with age and weekly......The aim of the study was to estimate active knee flexion and active knee extension in athletes and to investigate the potential association of each to different types of sports activity. Active knee extension and active knee flexion was measured in 339 athletes. Active knee extension...... hours of soccer, European team handball and swimming. The results point to sport-specific adaptation of active knee flexion and active knee extension. Udgivelsesdato: 1999-Apr...

  19. Risks of hip and knee replacement

    Science.gov (United States)

    ... is normal to lose blood during and after hip or knee replacement surgery. Some people need a ... clot form are higher during and soon after hip or knee replacement surgery. Sitting or lying down ...

  20. Knee Confidence as it Relates to Self-Reported and Objective Correlates of Knee Osteoarthritis

    DEFF Research Database (Denmark)

    Skou, Søren T; Rasmussen, Sten; Simonsen, Ole

    2015-01-01

    osteoarthritis (OA). Background Lack of knee confidence is a frequent symptom in patients with knee OA, but little is known of associations between knee confidence and other common correlates of knee OA. Methods Baseline data from 220 patients with knee OA were applied in ordinal regression analyses, with knee...... confidence, assessed using item Q3 of the Knee injury and Osteoarthritis Outcome Score, as the dependent variable and self-reported (pain on walking, general health, fear of movement, self-efficacy, function, and previous serious injury) and objective measures (muscle strength, 20-m walk time.......21; 95% CI: 1.09, 1.34), and general health (OR = 0.024; 95% CI: 0.002, 0.259) explained 19% of the variance in knee confidence (Pcommon finding in individuals with knee OA. Pain on walking was confirmed as a correlate of knee confidence, whereas...

  1. Slightly flexed knee position within a standard knee coil: MR delineation of the anterior cruciate ligament

    Energy Technology Data Exchange (ETDEWEB)

    Niitsu, M.; Itai, Y. [Department of Radiology, Institute of Clinical Medicine, University of Tsukuba, Tennodai, Tsukuba, Ibaraki 305 (Japan); Ikeda, K. [Department of Orthopedic Surgery, Institute of Clinical Medicine, University of Tsukuba, Tennodai, Tsukuba, Ibaraki 305 (Japan)

    1998-02-01

    The purpose of this study was to assess the value of positioning the knee slightly flexed within a standard MR knee coil in delineation of the anterior cruciate ligament (ACL). Within the confined space of a commercially available knee coil, knee could bend as much as 30 , average 17 of flexion. Sets of oblique sagittal MR images were obtained at both fully extended and slightly flexed positions. Twenty-two normal knees and 18 knees with ACL tears were examined and paired MR images were evaluated by two observers. Compared with knee extension, the MR images for knee flexion provided better clarity in 57 % of reviews of full length of the ACL and 53 % of the femoral attachment. In the extended position the anterior margin of the ligament was obscured due to partial averaging with the intercondylar roof. We recommend examining the knee in an achievable flexed position within the standard knee coil. (orig.) With 3 figs., 1 tab., 6 refs.

  2. Knee extensor muscle weakness is a risk factor for development of knee osteoarthritis

    DEFF Research Database (Denmark)

    Oiestad, B E; Juhl, C B; Eitzen, I

    2015-01-01

    The objective of this study was to perform a systematic review and meta-analysis on the association between knee extensor muscle weakness and the risk of developing knee osteoarthritis. A systematic review and meta-analysis was conducted with literature searches in Medline, SPORTDiscus, EMBASE......, CINAHL, and AMED. Eligible studies had to include participants with no radiographic or symptomatic knee osteoarthritis at baseline; have a follow-up time of a minimum of 2 years, and include a measure of knee extensor muscle strength. Hierarchies for extracting data on knee osteoarthritis and knee...... extensor muscle strength were defined prior to data extraction. Meta-analysis was applied on the basis of the odds ratios (ORs) of developing symptomatic knee osteoarthritis or radiographic knee osteoarthritis in subjects with knee extensor muscle weakness. ORs for knee osteoarthritis and 95% confidence...

  3. Slightly flexed knee position within a standard knee coil: MR delineation of the anterior cruciate ligament

    International Nuclear Information System (INIS)

    Niitsu, M.; Itai, Y.; Ikeda, K.

    1998-01-01

    The purpose of this study was to assess the value of positioning the knee slightly flexed within a standard MR knee coil in delineation of the anterior cruciate ligament (ACL). Within the confined space of a commercially available knee coil, knee could bend as much as 30 , average 17 of flexion. Sets of oblique sagittal MR images were obtained at both fully extended and slightly flexed positions. Twenty-two normal knees and 18 knees with ACL tears were examined and paired MR images were evaluated by two observers. Compared with knee extension, the MR images for knee flexion provided better clarity in 57 % of reviews of full length of the ACL and 53 % of the femoral attachment. In the extended position the anterior margin of the ligament was obscured due to partial averaging with the intercondylar roof. We recommend examining the knee in an achievable flexed position within the standard knee coil. (orig.)

  4. KNEE PROPRIOCEPTION FOLLOWING MENISCAL REPAIR

    Directory of Open Access Journals (Sweden)

    Brytsko A. A.

    2018-02-01

    Full Text Available Background. It is well known that meniscectomy leads to osteoarthritis of the knee and proprioception impairment. Objective. The aim of this study was to assess retrospectively the joint position sense after meniscal suture and partial medial meniscal resection and to estimate the patients’ satisfaction with knee function. Material and Methods. We evaluated the outcomes of 27 patients after meniscal repair and compared them to those of 24 patients after partial meniscal resection. We estimated the joint position sense at 30°, 45° and 60° of flexion using the Biodex system 4 Pro. All patients were assessed with the IKDC 2000 subjective knee score. Results. A statistically significant worsening in reproducing the injured joint position in comparison to the healthy limb in both groups was observed. These impairments were mostly expressed at 45° and 60° of knee flexion, and were worsening over time in the group of patients who had undergone medial meniscal resection. An average value by the IKDC 2000 scale after 24 months in the meniscorrhaphy group was 76.73 ± 11.17% and 68.93 ± 14.76% after partial medial meniscal resection. Сonclusion. The control over position of the knee is not impaired after meniscal repair. An overall satisfaction with joint function is higher in patients who undergo meniscal suture in comparison to the partial medial meniscal resection group.

  5. The Knee: Theory and Experiment

    International Nuclear Information System (INIS)

    Yodh, Gaurang B

    2006-01-01

    A review of current status of theoretical paradigm and results of direct and indirect experiments to study cosmic rays through the knee region are presented and discussed. There is general agreement that the knee is around a PeV and that it reflects a rigidity cutoff. The composition of cosmic rays in the knee region is mixed and changing with energy. The two direct experiments, JACEE and RUNJOB with measurements in the 100 TeV per particle to 1000 TeV per particle and with similar exposures do not agree. While JACEE indicates a increase in (lnA) from its low energy value of 1.5 to a value closer to 3 , the RUNJOB experiment sees no change in the composition albeit with large uncertainty. Of the indirect experiments, KASKADE, SPASEAMANDA, HEGRA-Airobic, CACTI, TUNKA and Tibet favor ''Heavy'' composition above the knee and beyond. The KASKADE energy range extends to 100 PeV where their analysis indicates iron dominance. KASKADE does not see a proton rigidity cutoff until about 3 PeV, while Tibet measures a steepening of the proton slope at a few hundred TeV. BLANCA and DICE favor little composition change or a change towards a proton dominated composition around 10 PeV. We need experiments with much better mass resolution in the energy range of the knee and a more quantitative understanding of the hadron production in the forward region at these energies to make definitive progress

  6. TOTAL KNEE REPLACEMENT IN PATIENTS WITH BELOW-KNEE AMPUTATION

    Science.gov (United States)

    Karam, Matthew D; Willey, Michael; Shurr, Donald G

    2010-01-01

    Total knee replacement (TKR) is reserved for patients with severe and disabling arthritis that is non-responsive to conservative measures. Based on existing data, total knee replacement is a safe and cost-effective treatment for alleviating pain and improving physical function in patients who do not respond to conservative therapy. Despite the large variation in health status of patients and types of prosthesis implanted, total knee replacement has proven to be a relatively low risk and successful operation. Each year in the United States surgeons perform approximately 300,000 TKR.1 Likewise, lower extremity amputation is commonly performed in the United States with an annual incidence of 110,000 per year.2 Nearly 70% of all lower extremity amputations are performed as the result of chronic vascular disease, followed by trauma (22%), congenital etiology and tumor (4% each).3 Approximately 50% of all lower extremity amputations are performed secondary to complications from Diabetes Mellitus. Norvell et al. demonstrated that patients who have previously undergone transtibial amputation and ambulate with a prosthesis are more likely to develop degenerative joint disease in the con-tralateral extremity than the ipsilateral extremity.4 Further, radiographic changes consistent with osteoporosis have been demonstrated in up to 88% of limbs that have undergone transtibial amputation.8 To our knowledge, there have been only three reported cases of total knee replacement in patients with ipsilateral transtibial amputation.5,7 The purpose of the present study is to review the existing data on total knee replacement in patients who have undergone transtibial amputation. Further we present a patient with a transtibial amputation who underwent contralateral total knee replacement. PMID:21045987

  7. DNA adduct formation by the ubiquitous environmental pollutant 3-nitrobenzanthrone and its metabolites in rats

    International Nuclear Information System (INIS)

    Arlt, Volker M.; Sorg, Bernd L.; Osborne, Martin; Hewer, Alan; Seidel, Albrecht; Schmeiser, Heinz H.; Phillips, David H.

    2003-01-01

    Diesel exhaust is known to induce tumours in animals and is suspected of being carcinogenic in humans. Of the compounds found in diesel exhaust, 3-nitrobenzanthrone (3-NBA) is an extremely potent mutagen and suspected human carcinogen forming multiple DNA adducts in vitro. 3-Aminobenzanthrone (3-ABA), 3-acetylaminobenzanthrone (3-Ac-ABA), and N-acetyl-N-hydroxy-3-aminobenzanthrone (N-Ac-N-OH-ABA) were identified as 3-NBA metabolites. In order to gain insight into the pathways of metabolic activation leading to 3-NBA-derived DNA adducts we treated Wistar rats intraperitoneally with 2 mg/kg body weight of 3-NBA, 3-ABA, 3-Ac-ABA, or N-Ac-N-OH-ABA and compared DNA adducts present in different organs. With each compound either four or five DNA adduct spots were detected by TLC in all tissues examined (lung, liver, kidney, heart, pancreas, and colon) using the nuclease P1 or butanol enrichment version of the 32 P-postlabelling method, respectively. Using HPLC co-chromatographic analysis we showed that all major 3-NBA-DNA adducts produced in vivo in rats are derived from reductive metabolites bound to purine bases and lack an N-acetyl group. Our results indicate that 3-NBA metabolites (3-ABA, 3-Ac-ABA and N-Ac-N-OH-ABA) undergo several biotransformations and that N-hydroxy-3-aminobenzanthrone (N-OH-ABA) appears to be the common intermediate in 3-NBA-derived DNA adduct formation. Therefore, 3-NBA-DNA adducts are useful biomarkers for exposure to 3-NBA and its metabolites and may help to identify enzymes involved in their metabolic activation

  8. Effects of timing of signal indicating jump directions on knee biomechanics in jump-landing-jump tasks.

    Science.gov (United States)

    Stephenson, Mitchell L; Hinshaw, Taylour J; Wadley, Haley A; Zhu, Qin; Wilson, Margaret A; Byra, Mark; Dai, Boyi

    2018-03-01

    A variety of the available time to react (ATR) has been utilised to study knee biomechanics during reactive jump-landing tasks. The purpose was to quantify knee kinematics and kinetics during a jump-land-jump task of three possible directions as the ATR was reduced. Thirty-four recreational athletes performed 45 trials of a jump-land-jump task, during which the direction of the second jump (lateral, medial or vertical) was indicated before they initiated the first jump, the instant they initiated the first jump, 300 ms before landing, 150 ms before landing or at the instant of landing. Knee joint angles and moments close to the instant of landing were significantly different when the ATR was equal to or more than 300 ms before landing, but became similar when the ATR was 150 ms or 0 ms before landing. As the ATR was decreased, knee moments decreased for the medial jump direction, but increased for the lateral jump direction. When the ATR is shorter than an individual's reaction time, the movement pattern cannot be pre-planned before landing. Knee biomechanics are dependent on the timing of the signal and the subsequent jump direction. Precise control of timing and screening athletes with low ATR are suggested.

  9. Biomechanical balance response during induced falls under dual task conditions in people with knee osteoarthritis.

    Science.gov (United States)

    Levinger, Pazit; Nagano, Hanatsu; Downie, Calum; Hayes, Alan; Sanders, Kerrie M; Cicuttini, Flavia; Begg, Rezaul

    2016-07-01

    People with knee osteoarthritis (OA) are at twice the risk of falling compared to older people without knee OA, however the mechanism for this is poorly understood. This study investigated the biomechanical response of the trunk and lower limb joints during a forward induced fall under different task conditions in people with and without knee OA. Twenty-four participants with OA (68.6±6.2 years) and 15 asymptomatic controls (72.4±4.8 years) participated in the study. Forward fall was induced by releasing participants from a static forward leaning position. Participants were required to recover balance during three conditions: normal, physical (obstacle clearance) and cognitive dual tasks (counting backwards). Spatiotemporal parameters, lower limb joint kinematics and kinetics of the recovery limb were compared between the two groups and across the three task conditions. The OA group demonstrated slower spatio-temporal characteristics and reduced hip and knee flexion angles, joint moments/powers and reduced muscle negative work at the knee and ankle (pfall, participants with OA demonstrated difficulty in absorbing the impact and slowing down the forward momentum of the body during a recovery step. Moreover, poor dynamic postural control was demonstrated as task complexity increased. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. A Soft-Inflatable Exosuit for Knee Rehabilitation: Assisting Swing Phase During Walking

    Directory of Open Access Journals (Sweden)

    Saivimal Sridar

    2018-05-01

    Full Text Available In this paper, we present a soft-inflatable exosuit to assist knee extension during gait training for stroke rehabilitation. The soft exosuit is designed to provide 25% of the knee moment required during the swing phase of the gait cycle and is integrated with inertial measurement units (IMUs and smart shoe insole sensors to improve gait phase detection and controller design. The stiffness of the knee joint during level walking is computed using inverse dynamics. The soft-inflatable actuators, with an I cross-section, are mechanically characterized at varying angles to enable generation of the required stiffness outputs. A linear relation between the inflatable actuator stiffness and internal pressure as a function of the knee angle is obtained, and a two-layer stiffness controller is implemented to assist the knee joint by providing appropriate stiffness during the swing phase. Finally, to evaluate the ability of the exosuit to assist in swing motion, surface-electromyography (sEMG sensors are placed on the three muscle groups of the quadriceps and two groups of the hamstrings, on three healthy participants. A reduction in muscle activity of the rectus femoris, vastus lateralis, and vastus medialis is observed, which demonstrates feasibility of operation and potential future usage of the soft inflatable exosuit by impaired users.

  11. Barefoot running and hip kinematics: good news for the knee?

    Science.gov (United States)

    McCarthy, Colm; Fleming, Neil; Donne, Bernard; Blanksby, Brian

    2015-05-01

    Patellofemoral pain and iliotibial band syndromes are common running injuries. Excessive hip adduction (HADD), hip internal rotation (HIR), and contralateral pelvic drop (CLPD) during running have been suggested as causes of injury in female runners. This study compared these kinematic variables during barefoot and shod running. Three-dimensional gait analyses of 23 habitually shod, uninjured female recreational athletes running at 3.33 m·s while shod and barefoot were studied. Spatiotemporal and kinematic data at initial contact (IC), 10% of stance (corresponding to the vertical impact peak), and peak angles were collected from each participant for HADD, HIR, and CLPD, and differences were compared across footwear conditions. Step rates when running barefoot were 178 ± 13 versus 172 ± 11 steps per minute when shod (P strike patterns changed from a group mean heel-toe latency indicating a rear-foot strike (20.8 ms) when shod, to one indicating a forefoot strike (-1.1 ms) when barefoot (P knee injuries in female runners, barefoot running could have potential for injury prevention or treatment in this cohort.

  12. Are undesirable contact kinematics minimized after kinematically aligned total knee arthroplasty? An intersurgeon analysis of consecutive patients.

    Science.gov (United States)

    Howell, Stephen M; Hodapp, Esther E; Vernace, Joseph V; Hull, Maury L; Meade, Thomas D

    2013-10-01

    Tibiofemoral contact kinematics or knee implant motions have a direct influence on patient function and implant longevity and should be evaluated for any new alignment technique such as kinematically aligned total knee arthroplasty (TKA). Edge loading of the tibial liner and external rotation (reverse of normal) and adduction of the tibial component on the femoral component are undesirable contact kinematics that should be minimized. Accordingly, this study determined whether the overall prevalence of undesirable contact kinematics during standing, mid kneeling near 90 degrees and full kneeling with kinematically aligned TKA are minimal and not different between groups of consecutive patients treated by different surgeons. Three surgeons were asked to perform cemented, kinematically aligned TKA with patient-specific guides in a consecutive series of patients with their preferred cruciate-retaining (CR) implant. In vivo tibiofemoral contact positions were obtained using a 3- to 2-dimensional image registration technique in 69 subjects (Vanguard CR-TKA N = 22, and Triathlon CR-TKA N = 47). Anterior or posterior edge loading of the tibial liner was not observed. The overall prevalence of external rotation of the tibial component on the femoral component of 6 % was low and not different between surgeons (n.s.). The overall prevalence of adduction of the tibial component on the femoral component of 4 % was low and not different between surgeons (n.s.). Kinematically aligned TKA minimized the undesirable contact kinematics of edge loading of the tibial liner, and external rotation and adduction of the tibial component on the femoral component during standing and kneeling, which suggests an optimistic prognosis for durable long-term function. III.

  13. Proprioception in knee osteoarthritis: a narrative review

    NARCIS (Netherlands)

    Knoop, J.; Steultjens, M.P.M.; van der Leeden, M.; van der Esch, M.; Thorstensson, C.A.; Roorda, L.D.; Lems, W.F.; Dekker, J.

    2011-01-01

    Objective: To give an overview of the literature on knee proprioception in knee osteoarthritis (OA) patients. Method: A literature search was performed and reviewed using the narrative approach. Results: (1) Three presumed functions of knee proprioception have been described in the literature:

  14. Lifestyle, Environmental, and Genetic Predictors of Bulky DNA Adducts in a Study Population Nested within a Prospective Danish Cohort

    DEFF Research Database (Denmark)

    Eriksen, K. T.; Sørensen, M.; Autrup, H.

    2010-01-01

    Danish cohort. At enrollment, blood samples were collected and information on lifestyle, including dietary and smoking habits, obtained. Previously, bulky DNA adducts were measured in 245 individuals who developed lung cancer and 255 control members of the cohort. Of these 500 individuals, data on 375...... of bulky DNA adduct levels were analyzed by univariate and multivariate regression analyses. Women tended to have higher adduct levels than men. Living in central Copenhagen and surface darkness of fried meat and fish were associated with quantitative higher adduct levels. No significant associations were...

  15. Aminoazo dye-protein-adduct enhances inhibitory effect on digestibility and damages to Gastro-Duodenal-Hepatic axis.

    Directory of Open Access Journals (Sweden)

    Li-Yun Lin

    Full Text Available 4-Dimethylaminoazobenzene (DAB, methyl yellow, or butter yellow, a human carcinogen, has been banned for use in foods since 1988. In 2014, DAB adulteration in Tofu occurred in Taiwan. We hypothesize that DAB can form [DAB•SBP]adduct adduct with soybean protein (SBP which could damage Gastro-Duodenal-Hepatic axis. Sprague-Dawley rats gavage fed [DAB•SBP]adduct adduct revealed severely reduced body weight and damaged duodenum, liver, hepatic mitochondria, and spleen. Hepatic levels of glutathione and ATP were severely reduced. Serum GOT and GPT were substantially elevated. Analysis by the adsorption isotherm clearly revealed DAB formed very stable [DAB•SBP]adduct adduct at 1:1 molar ration (Phase A. The equilibrium constant of this colloidal adduct [DAB•SBP]adduct was KeqA = ∝, behaving as the most stable and toxic species. At higher protein concentration (Phase C it formed conjugate [DAB×SBPgross]conjugate, with KeqC = 3.23×10-2 mg/mL, implicating a moderately strong adsorption. The in vitro pepsin digestibility test showed apparently reduced digestibility by 27% (by Ninhydrin assay or 8% (by Bradford assay. Conclusively, this is the first report indicating that [DAB•SBP]adduct potentially is capable to damage the Gastro-Duodenal-Hepatic axis.

  16. On multipole moments in general relativity

    International Nuclear Information System (INIS)

    Hoenselaers, C.

    1986-01-01

    In general situations, involving gravitational waves the question of multiple moments in general relativity restricts the author to stationary axisymmetric situations. Here it has been shown that multipole moments, a set of numbers defined at spatial infinity as far away from the source as possible, determine a solution of Einstein's equations uniquely. With the rather powerful methods for generating solutions one might hope to get solutions with predefined multipole moments. Before doing so, however, one needs an efficient algorithm for calculating the moments of a given solution. Chapter 2 deals with a conjecture pertaining to such a calculational procedure and shows it to be not true. There is another context in which multipole moments are important. Consider a system composed of several objects. To separate, if possible, the various parts of their interaction, one needs a definition for multipole moments of individual members of a many body system. In spite of the fact that there is no definition for individual moments, with the exception of mass and angular momentum, Chapter 3 shows what can be done for the double Kerr solution. The authors can identify various terms in he interaction of two aligned Kerr objects and show that gravitational spin-spin interaction is indeed proportional to the product of the angular momenta

  17. Table of Nuclear Electric Quadrupole Moments

    International Nuclear Information System (INIS)

    Stone, N.J.

    2013-12-01

    This Table is a compilation of experimental measurements of static electric quadrupole moments of ground states and excited states of atomic nuclei throughout the periodic table. To aid identification of the states, their excitation energy, half-life, spin and parity are given, along with a brief indication of the method and any reference standard used in the particular measurement. Experimental data from all quadrupole moment measurements actually provide a value of the product of the moment and the electric field gradient [EFG] acting at the nucleus. Knowledge of the EFG is thus necessary to extract the quadrupole moment. A single recommended value of the moment is given for each state, based, for each element, wherever possible, upon a standard reference moment for a nuclear state of that element studied in a situation in which the electric field gradient has been well calculated. For several elements one or more subsidiary reference EFG/moment references are required and their use is specified. The literature search covers the period to mid-2013. (author)

  18. Theory of nuclear magnetic moments - LT-35

    Energy Technology Data Exchange (ETDEWEB)

    Kerman, A. K.

    1952-09-15

    The purpose of these notes is to give an account of some attempts at interpreting the observed values of nuclear magnetic moments. There is no attempt at a complete summary of the field as that would take much more space than is used here. In many cases the arguments are only outlined and references are given for those interested in further details. A discussion of the theory of nuclear magnetic moments necessitates many excursions into the details of the nuclear models because the magnetic moments have a direct bearing on the validity of these models. However the main emphasis here is on those features which tend to explain the magnetic moments and other evidence is not discussed unless it has a direct bearing on the problem. In the first part of the discussion the Shell Model of the nucleus is used, as this model seems to correlate a large body of data relating to the heavier nuclei. Included here are the modifications proposed to explain the fact that the experimental magnetic moments do not fit quantitatively with the exact predictions of the Shell Model. The next sections deal with some of the more drastic modifications introduced to explain the large nuclear quadrupole moments and the effect of these modifications on the magnetic moments. Finally we turn to more detailed investigations of the light nuclei, in particular the - Conjugate nuclei. (author)

  19. Maximum acceptable weight of lift reflects peak lumbosacral extension moments in a functional capacity evaluation test using free style, stoop and squat lifting.

    Science.gov (United States)

    Kuijer, P P F M; van Oostrom, S H; Duijzer, K; van Dieën, J H

    2012-01-01

    It is unclear whether the maximum acceptable weight of lift (MAWL), a common psychophysical method, reflects joint kinetics when different lifting techniques are employed. In a within-participants study (n = 12), participants performed three lifting techniques--free style, stoop and squat lifting from knee to waist level--using the same dynamic functional capacity evaluation lifting test to assess MAWL and to calculate low back and knee kinetics. We assessed which knee and back kinetic parameters increased with the load mass lifted, and whether the magnitudes of the kinetic parameters were consistent across techniques when lifting MAWL. MAWL was significantly different between techniques (p = 0.03). The peak lumbosacral extension moment met both criteria: it had the highest association with the load masses lifted (r > 0.9) and was most consistent between the three techniques when lifting MAWL (ICC = 0.87). In conclusion, MAWL reflects the lumbosacral extension moment across free style, stoop and squat lifting in healthy young males, but the relation between the load mass lifted and lumbosacral extension moment is different between techniques. Tests of maximum acceptable weight of lift (MAWL) from knee to waist height are used to assess work capacity of individuals with low-back disorders. This article shows that the MAWL reflects the lumbosacral extension moment across free style, stoop and squat lifting in healthy young males, but the relation between the load mass lifted and lumbosacral extension moment is different between techniques. This suggests that standardisation of lifting technique used in tests of the MAWL would be indicated if the aim is to assess the capacity of the low back.

  20. Computational modelling of locomotor muscle moment arms in the basal dinosaur Lesothosaurus diagnosticus: assessing convergence between birds and basal ornithischians.

    Science.gov (United States)

    Bates, Karl T; Maidment, Susannah C R; Allen, Vivian; Barrett, Paul M

    2012-03-01

    ornithischians and birds. Craniad migration of the iliofemoralis group muscles in birds correlates with increased leverage and use of medial femoral rotation to counter stance phase adduction moments at the hip. In Lesothosaurus the iliofemoralis group maintains significantly higher moment arms for abduction, consistent with the hip abduction mode of lateral limb support hypothesized for basal dinosaurs. Sensitivity analysis highlights ambiguity in the role of musculature associated with the retroverted pubis (puboischiofemoralis externus group) in ornithischians. However, it seems likely that this musculature may have predominantly functioned similarly to homologous muscles in extant birds, activating during the swing phase to adduct the lower limb through lateral rotation of the femur. Overall the results suggest that locomotor muscle leverage in Lesothosaurus (and by inference basal ornithischians in general) was more similar to that of other non-avian dinosaurs than the ostrich, representing what was probably the basal dinosaur condition. This work thereby contradicts previous hypotheses of ornithischian-bird functional convergence. © 2012 The Authors. Journal of Anatomy © 2012 Anatomical Society.

  1. DNA adduct formation and mutation induction by aristolochic acid in rat kidney and liver

    International Nuclear Information System (INIS)

    Mei, Nan; Arlt, Volker M.; Phillips, David H.; Heflich, Robert H.; Chen, Tao

    2006-01-01

    Aristolochic acid (AA) is a potent nephrotoxin and carcinogen and is the causative factor for Chinese herb nephropathy. AA has been associated with the development of urothelial cancer in humans, and kidney and forestomach tumors in rodents. To investigate the molecular mechanisms responsible for the tumorigenicity of AA, we determined the DNA adduct formation and mutagenicity of AA in the liver (nontarget tissue) and kidney (target tissue) of Big Blue rats. Groups of six male rats were gavaged with 0, 0.1, 1.0 and 10.0 mg AA/kg body weight five times/week for 3 months. The rats were sacrificed 1 day after the final treatment, and the livers and kidneys were isolated. DNA adduct formation was analyzed by 32 P-postlabeling and mutant frequency (MF) was determined using the λ Select-cII Mutation Detection System. Three major adducts (7-[deoxyadenosin-N 6 -yl]-aristolactam I, 7-[deoxyadenosin-N 6 -yl]-aristolactam II and 7-[deoxyguanosin-N 2 -yl]-aristolactam I) were identified. There were strong linear dose-responses for AA-induced DNA adducts in treated rats, ranging from 25 to 1967 adducts/10 8 nucleotides in liver and 95-4598 adducts/10 8 nucleotides in kidney. A similar trend of dose-responses for mutation induction also was found, the MFs ranging from 37 to 666 x 10 -6 in liver compared with the MFs of 78-1319 x 10 -6 that we previously reported for the kidneys of AA-treated rats. Overall, kidneys had at least two-fold higher levels of DNA adducts and MF than livers. Sequence analysis of the cII mutants revealed that there was a statistically significant difference between the mutation spectra in both kidney and liver of AA-treated and control rats, but there was no significant difference between the mutation spectra in AA-treated livers and kidneys. A:T → T:A transversion was the predominant mutation in AA-treated rats; whereas G:C → A:T transition was the main type of mutation in control rats. These results indicate that the AA treatment that eventually

  2. DNA adduct formation and mutation induction by aristolochic acid in rat kidney and liver

    Energy Technology Data Exchange (ETDEWEB)

    Mei, Nan [Division of Genetic and Reproductive Toxicology, National Center for Toxicological Research, FDA, Jefferson, AR 72079 (United States)]. E-mail: nan.mei@fda.hhs.gov; Arlt, Volker M. [Section of Molecular Carcinogenesis, Institute of Cancer Research, Cotswold Road, Sutton, Surrey SM2 5NG (United Kingdom); Phillips, David H. [Section of Molecular Carcinogenesis, Institute of Cancer Research, Cotswold Road, Sutton, Surrey SM2 5NG (United Kingdom); Heflich, Robert H. [Division of Genetic and Reproductive Toxicology, National Center for Toxicological Research, FDA, Jefferson, AR 72079 (United States); Chen, Tao [Division of Genetic and Reproductive Toxicology, National Center for Toxicological Research, FDA, Jefferson, AR 72079 (United States)

    2006-12-01

    Aristolochic acid (AA) is a potent nephrotoxin and carcinogen and is the causative factor for Chinese herb nephropathy. AA has been associated with the development of urothelial cancer in humans, and kidney and forestomach tumors in rodents. To investigate the molecular mechanisms responsible for the tumorigenicity of AA, we determined the DNA adduct formation and mutagenicity of AA in the liver (nontarget tissue) and kidney (target tissue) of Big Blue rats. Groups of six male rats were gavaged with 0, 0.1, 1.0 and 10.0 mg AA/kg body weight five times/week for 3 months. The rats were sacrificed 1 day after the final treatment, and the livers and kidneys were isolated. DNA adduct formation was analyzed by {sup 32}P-postlabeling and mutant frequency (MF) was determined using the {lambda} Select-cII Mutation Detection System. Three major adducts (7-[deoxyadenosin-N {sup 6}-yl]-aristolactam I, 7-[deoxyadenosin-N {sup 6}-yl]-aristolactam II and 7-[deoxyguanosin-N {sup 2}-yl]-aristolactam I) were identified. There were strong linear dose-responses for AA-induced DNA adducts in treated rats, ranging from 25 to 1967 adducts/10{sup 8} nucleotides in liver and 95-4598 adducts/10{sup 8} nucleotides in kidney. A similar trend of dose-responses for mutation induction also was found, the MFs ranging from 37 to 666 x 10{sup -6} in liver compared with the MFs of 78-1319 x 10{sup -6} that we previously reported for the kidneys of AA-treated rats. Overall, kidneys had at least two-fold higher levels of DNA adducts and MF than livers. Sequence analysis of the cII mutants revealed that there was a statistically significant difference between the mutation spectra in both kidney and liver of AA-treated and control rats, but there was no significant difference between the mutation spectra in AA-treated livers and kidneys. A:T {sup {yields}} T:A transversion was the predominant mutation in AA-treated rats; whereas G:C {sup {yields}} A:T transition was the main type of mutation in control

  3. Moments analysis of concurrent Poisson processes

    International Nuclear Information System (INIS)

    McBeth, G.W.; Cross, P.

    1975-01-01

    A moments analysis of concurrent Poisson processes has been carried out. Equations are given which relate combinations of distribution moments to sums of products involving the number of counts associated with the processes and the mean rate of the processes. Elimination of background is discussed and equations suitable for processing random radiation, parent-daughter pairs in the presence of background, and triple and double correlations in the presence of background are given. The theory of identification of the four principle radioactive series by moments analysis is discussed. (Auth.)

  4. Exchange currents for hypernuclear magnetic moments

    International Nuclear Information System (INIS)

    Saito, K.; Oka, M.; Suzuki, T.

    1997-01-01

    The meson (K and π) exchange currents for the hypernuclear magnetic moments are calculated using the effective Lagrangian method. The seagull diagram, the mesonic diagram and the Σ 0 -excitation diagram are considered. The Λ-N exchange magnetic moments for 5 Λ He and A=6 hypernuclei are calculated employing the harmonic oscillator shell model. It is found that the two-body correction is about -9% of the single particle value for 5 Λ He. The π exchange current, induced only in the Σ 0 -excitation diagram, is found to give dominant contribution for the isovector magnetic moments of hypernuclei with A=6. (orig.)

  5. Moment analysis of hadronic vacuum polarization

    Directory of Open Access Journals (Sweden)

    Eduardo de Rafael

    2014-09-01

    Full Text Available I suggest a new approach to the determination of the hadronic vacuum polarization (HVP contribution to the anomalous magnetic moment of the muon aμHVP in lattice QCD. It is based on properties of the Mellin transform of the hadronic spectral function and their relation to the HVP self-energy in the Euclidean. I show how aμHVP is very well approximated by a few moments associated to this Mellin transform and how these moments can be evaluated in lattice QCD, providing thus a series of tests when compared with the corresponding determinations using experimental data.

  6. Moment analysis of hadronic vacuum polarization

    International Nuclear Information System (INIS)

    Rafael, Eduardo de

    2014-01-01

    I suggest a new approach to the determination of the hadronic vacuum polarization (HVP) contribution to the anomalous magnetic moment of the muon a μ HVP in lattice QCD. It is based on properties of the Mellin transform of the hadronic spectral function and their relation to the HVP self-energy in the Euclidean. I show how a μ HVP is very well approximated by a few moments associated to this Mellin transform and how these moments can be evaluated in lattice QCD, providing thus a series of tests when compared with the corresponding determinations using experimental data

  7. Moment analysis of hadronic vacuum polarization

    Energy Technology Data Exchange (ETDEWEB)

    Rafael, Eduardo de

    2014-09-07

    I suggest a new approach to the determination of the hadronic vacuum polarization (HVP) contribution to the anomalous magnetic moment of the muon a{sub μ}{sup HVP} in lattice QCD. It is based on properties of the Mellin transform of the hadronic spectral function and their relation to the HVP self-energy in the Euclidean. I show how a{sub μ}{sup HVP} is very well approximated by a few moments associated to this Mellin transform and how these moments can be evaluated in lattice QCD, providing thus a series of tests when compared with the corresponding determinations using experimental data.

  8. Moment approach to charged particle beam dynamics

    International Nuclear Information System (INIS)

    Channell, P.J.

    1983-01-01

    We have derived the hierarchy of moment equations that describes the dynamics of charged-particle beams in linear accelerators and can truncate the hierarchy at any level either by discarding higher moments or by a cumulant expansion discarding only correlation functions. We have developed a procedure for relating the density expansion linearly to the moments to any order. The relation of space-charge fields to the density has been derived; and an accurate, systematic, and computationally convenient expansion of the resultant integrals has been developed

  9. Dipole moments of the rho meson

    International Nuclear Information System (INIS)

    Hecht, M.B.; McKellar, B.H.P.

    1997-04-01

    The electric and magnetic dipole moments (EDM) of the rho meson are calculated using the propagators and vertices derived from the quantum chromodynamics Dyson-Schwinger equations. Results obtained from using the Bethe-Salpeter amplitude studied by Chappell, Mitchell et. al., and Pichowsky and Lee, are compared. The rho meson EDM is generated through the inclusion of a quark electric dipole moment, which is left as a free variable. These results are compared to the perturbative results to obtain a measure of the effects of quark interactions and confinement. The two dipole moments are also calculated using the phenomenological MIT bag model to provide a further basis for comparison

  10. Moments method in the theory of accelerators

    International Nuclear Information System (INIS)

    Perel'shtejn, Eh.A.

    1984-01-01

    The moments method is widely used for solution of different physical and calculation problems in the theory of accelerators, magnetic optics and dynamics of high-current beams. Techniques using moments of the second order-mean squape characteristics of charged particle beams is shown to be most developed. The moments method is suitable and sometimes even the only technique applicable for solution of computerized problems on optimization of accelerating structures, beam transport channels, matching and other systems with accout of a beam space charge

  11. Targeted mutations induced by a single acetylaminofluorene DNA adduct in mammalian cells and bacteria

    International Nuclear Information System (INIS)

    Moryia, M.; Takeshita, M.; Johnson, F.; Peden, K.; Will, S.; Grollman, A.P.

    1988-01-01

    Mutagenic specificity of 2-acetylaminofluorene (AAF) has been established in mammalian cells and several strains of bacteria by using a shuttle plasmid vector containing a single N-(deoxyguanosin-8-yl)acetylaminofluorene (C8-dG-AAF) adduct. The nucleotide sequence of the gene conferring tetracycline resistance was modified by conservative codon replacement so as to accommodate the sequence d(CCTTCGCTAC) flanked by two restriction sites, Bsm I and Xho I. The corresponding synthetic oligodeoxynucleotide underwent reaction with 2-(N-acetoxy-N-acetylamino)-fluorene (AAAF), forming a single dG-AAF adduct. This modified oligodeoxynucleotide was hybridized to its complementary strand and ligated between the Bsm I and Xho I sites of the vector. Plasmids containing the C8-dG-AAF adduct were used to transfect simian virus 40-transformed simian kidney (COS-1) cells and to transform several AB strains of Escherichia coli. Colonies containing mutant plasmides were detected by hybridization to 32 P-labeled oligodeoxynucleotides. Presence of the single DNA adduct increased the mutation frequency by 8-fold in both COS cells and E. coli. Over 80% of mutations detected in both systems were targeted and represented G x C → C x G or G x C → T x A transversions or single nucleotide deletions. The authors conclude that modification of a deoxyguanosine residue with AAF preferentially induces mutations targeted at this site when a plasmid containing a single C8-dG-AAF adduct is introduced into mammalian cells or bacteria

  12. Chemical structure of the adducts formed by the oxidation of benzidine in the presence of phenols

    International Nuclear Information System (INIS)

    Josephy, P.D.; Mason, R.P.; Eling, T.

    1982-01-01

    Bioactivation of carcinogens by peroxidases has received increasing attention since the discovery of the oxidation of carcinogens by prostaglandin hydroperoxidase. Benzidine and 3,5,3',5'-tetramethylbenzidine are oxidized by horseradish peroxidase and prostaglandin synthase to two-electron oxidation products (di-imines). Di-imines readily react with the phenolic anti-oxidant butylated hydroxyanisole to form adducts. In this paper, we have studied the oxidation of benzidine by horseradish peroxidase in the presence of phenolic compounds and characterized the resultant benzidine/phenol adducts. A benzidine/2,6-dimethylphenol adduct was isolated and characterized by mass spectrometry and high field n.m.r. The reaction of [ 14 C]benzidine in the presence of horseradish peroxidase and phenol yielded only the benzidine/phenol adduct. Our results indicate that the benzidine/phenol adducts are analogous to the indoaniline dyes, differing only in substitution of a biphenyl group for a benzene ring. The reaction of benzidine di-imine with endogenous phenols may represent a new pathway for detoxication, removing potentially harmful metabolites of benzidine

  13. Inhibition of nicotine-DNA adduct formation by polyphenolic compounds in vitro

    International Nuclear Information System (INIS)

    Cheng Yan; Wang Haifang; Sun Hongfang; Li Hongli

    2004-01-01

    Nicotine[3-(1-methyl-2-pyrrolidinyl)-pyridine], a major alkaloid in tobacco products, has proven to be a potential genotoxic compound. Some polyphenolic compounds can suppress the DNA adduction, and hence act as the potential inhibitors of carcinogenesis. In this study, the inhibitory effects of three polyphenolic compounds, curcumin (diferuloylmethane), resveratrol (trans-3, 5, 4-trihydroxystilbene) and tea polyphenols, on the nicotine-DNA adduction have been investigated in vitro using radiolabelled nicotine and liquid scintillation counting (LSC) technique. Also, the inhibition mechanism of these chemopreventive agents in regard to the activity of the biotransformation enzymes, including cytochrome P450 (CYP450), cytochrome b 5 (CYb 5 ) and glutathione S-transferase (GST), has been studied. The results demonstrated that these three polyphenols induced marked dose-dependent decrease in nicotine-DNA adducts as compared with the controls. The elimination rate of adducts reached above 46% at the highest dose for all the three agents with 51.6% for resveratrol. Correspondingly, three polyphenols all suppressed CYP450 and CYb 5 , whereas curcumin and resveratrol induced GST. The authors may arrive at a point that the three polyphenols are beneficial to prevent the nicotine adduct formation, and thus may be used to block the potential carcinogenesis induced by nicotine. (authors)

  14. Aflatoxin B1-lysine adduct in dried blood spot samples of animals and humans.

    Science.gov (United States)

    Xue, Kathy S; Cai, Wenjie; Tang, Lili; Wang, Jia-Sheng

    2016-12-01

    Dried blood spots (DBS) were proposed as potentially viable method for exposure assessment of environmental toxicants in infant and young children. For this study, we validated an experimental protocol to quantify AFB 1 -lysine adduct in DBS samples of AFB 1 -treated F344 rats, as well as samples from human field study. Significant dose-response relationships in AFB 1 -lysine adduct formation were found in DBS samples of rats treated with single- and repeated-dose AFB 1 . AFB 1 -lysine levels in DBS samples were highly correlated with corresponding serum sample levels. The Person coefficients were 0.997 for the single-dose exposure, and 0.996 for the repeated-dose exposure. Levels of AFB 1 -lysine adduct had also good agreement between DBS and serum samples as shown by Bland-Altman plot analysis. For human field study samples (n = 36), a Pearson correlation coefficient of 0.784 was found between AFB 1 -lysine adduct levels of DBS and corresponding serum samples. Bland-Altman plots showed the distribution of the log differences between DBS and serum AFB 1 -lysine levels are within 95% confidence intervals. These results showed AFB 1 -lysine adduct levels in DBS cards and serum samples from animals and human samples are comparable, and the DBS technique and analytical protocol is a good means to assess AFB 1 exposure in infant and children populations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Induction of stable protein-deoxyribonucleic acid adducts in Chinese hamster cell chromatin by ultraviolet light

    International Nuclear Information System (INIS)

    Strniste, G.F.; Rall, S.C.

    1976-01-01

    Ultraviolet (uv)-light-mediated formation of protein-DNA adducts in Chinese hamster cell chromatin was investigated in an attempt to compare chromatin alterations induced in vitro with those observed in vivo. Three independent methods of analysis indicated stable protein-DNA associations: a membrane filter assay which retained DNA on the filter in the presence of high salt-detergent; a Sepharose 4B column assay in which protein eluted coincident with DNA; and a CsCl density gradient equilibrium assay which showed both protein and DNA banding at densities other than their respective native densities. Treatment of the irradiated chromatin with DNase provided further evidence that protein--DNA and not protein-protein adducts were being observed in the column assay. There is a fluence-dependent response of protein-DNA adduct formation when the chromatin is irradiated at low ionic strength and is linear for protein over the range studied. When the chromatin is exposed to differing conditions of pH, ionic strength, or divalent metal ion concentration, the quantity of adduct formed upon uv irradiation varies. Susceptibility to adduct formation can be partially explained in terms of the condensation state of the chromatin and other factors such as rearrangement, denaturation, and dissociation of the chromatin components. Besides providing information on the biological significance of these types of uv-induced lesions, this technique may be useful as a probe of chromatin structure

  16. Pyrrolizidine alkaloid-derived DNA adducts are common toxicological biomarkers of pyrrolizidine alkaloid N-oxides.

    Science.gov (United States)

    He, Xiaobo; Xia, Qingsu; Woodling, Kellie; Lin, Ge; Fu, Peter P

    2017-10-01

    There are 660 pyrrolizidine alkaloids (PAs) and PA N-oxides present in the plants, with approximately half being possible carcinogens. We previously reported that a set of four PA-derived DNA adducts is formed in the liver of rats administered a series of hepatocarcinogenic PAs and a PA N-oxide. Based on our findings, we hypothesized that this set of DNA adducts is a common biological biomarker of PA-induced liver tumor formation. In this study, we determined that rat liver microsomal metabolism of five hepatocarcinogenic PAs (lasiocarpine, retrorsine, riddelliine, monocrotaline, and heliotrine) and their corresponding PA N-oxides produced the same set of DNA adducts. Among these compounds, lasiocarpine N-oxide, retrorsine N-oxide, monocrotaline N-oxide, and heliotrine N-oxide are for first time shown to be able to produce these DNA adducts. These results further support the role of these DNA adducts as potential common biomarkers of PA-induced liver tumor initiation. Copyright © 2017. Published by Elsevier B.V.

  17. Pyrrolizidine alkaloid-derived DNA adducts are common toxicological biomarkers of pyrrolizidine alkaloid N-oxides

    Directory of Open Access Journals (Sweden)

    Xiaobo He

    2017-10-01

    Full Text Available There are 660 pyrrolizidine alkaloids (PAs and PA N-oxides present in the plants, with approximately half being possible carcinogens. We previously reported that a set of four PA-derived DNA adducts is formed in the liver of rats administered a series of hepatocarcinogenic PAs and a PA N-oxide. Based on our findings, we hypothesized that this set of DNA adducts is a common biological biomarker of PA-induced liver tumor formation. In this study, we determined that rat liver microsomal metabolism of five hepatocarcinogenic PAs (lasiocarpine, retrorsine, riddelliine, monocrotaline, and heliotrine and their corresponding PA N-oxides produced the same set of DNA adducts. Among these compounds, lasiocarpine N-oxide, retrorsine N-oxide, monocrotaline N-oxide, and heliotrine N-oxide are for first time shown to be able to produce these DNA adducts. These results further support the role of these DNA adducts as potential common biomarkers of PA-induced liver tumor initiation.

  18. Characterization of model peptide adducts with reactive metabolites of naphthalene by mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Nathalie T Pham

    Full Text Available Naphthalene is a volatile polycyclic aromatic hydrocarbon generated during combustion and is a ubiquitous chemical in the environment. Short term exposures of rodents to air concentrations less than the current OSHA standard yielded necrotic lesions in the airways and nasal epithelium of the mouse, and in the nasal epithelium of the rat. The cytotoxic effects of naphthalene have been correlated with the formation of covalent protein adducts after the generation of reactive metabolites, but there is little information about the specific sites of adduction or on the amino acid targets of these metabolites. To better understand the chemical species produced when naphthalene metabolites react with proteins and peptides, we studied the formation and structure of the resulting adducts from the incubation of model peptides with naphthalene epoxide, naphthalene diol epoxide, 1,2-naphthoquinone, and 1,4-naphthoquinone using high resolution mass spectrometry. Identification of the binding sites, relative rates of depletion of the unadducted peptide, and selectivity of binding to amino acid residues were determined. Adduction occurred on the cysteine, lysine, and histidine residues, and on the N-terminus. Monoadduct formation occurred in 39 of the 48 reactions. In reactions with the naphthoquinones, diadducts were observed, and in one case, a triadduct was detected. The results from this model peptide study will assist in data interpretation from ongoing work to detect peptide adducts in vivo as markers of biologic effect.

  19. MR imaging of the knee

    International Nuclear Information System (INIS)

    Mink, J.H.

    1987-01-01

    There is increasing evidence that MR imaging of the knee can accurately evaluate the menisci and the cruciate and collateral ligaments with an accuracy equal to that of conventional anthrography. MR imaging can, as a simple test, definitively assess a wide spectrum of the causes of knee pain, including osteonecrosis/osteochondritis dissecans, chondral and bony fractures, abnormal plicae, and chondromalacia. The presentation focuses on the optimal imaging parameters that will ensure accuracy and maximize patient throughput. The etiology and significance of meniscal signal is discussed, and the criteria for an MR imaging-based diagnosis of meniscal tears, cruciate and collateral ligament and extensor mechanism abnormalities, osteonecrosis, and stress fractures are presented

  20. Total knee arthroplasty in ochronosis

    Directory of Open Access Journals (Sweden)

    Vaibhav G. Patel, MBBS

    2015-09-01

    Full Text Available Alkaptonuria is disorder of tyrosine metabolism due to deficiency of homogentisic oxidase characterized by excretion of homogentisic acid in urine, deposition of oxidized homogensitate pigments in connective tissues and articular cartilages (ochronosis. The result is dark pigmentation and weakening of the tissues resulting in chronic inflammation and osteoarthritis. Management of alkaptonuric ochronic osteoarthritis is usually symptomatic and replacements have comparable outcomes to osteoarthritis in patients without ochronosis. I report a case of a patient with ochronosis of knee treated with total knee replacement and report operative pearls for surgery in this rare disorder.