Frederiksen, Henrik; Gaist, David; Petersen, Hans Christian
in life is a major problem in terms of prevalence, morbidity, functional limitations, and quality of life. It is therefore of interest to find a phenotype reflecting physical functioning which has a relatively high heritability and which can be measured in large samples. Hand grip strength is known......-55%). A powerful design to detect genes associated with a phenotype is obtained using the extreme discordant and concordant sib pairs, of whom 28 and 77 dizygotic twin pairs, respectively, were found in this study. Hence grip strength is a suitable phenotype for identifying genetic variants of importance to mid...
Goislard de Monsabert, Benjamin; Rossi, Jérémy; Berton, Eric; Vigouroux, Laurent
The aim of this study was to estimate muscle and joint forces during a power grip task. Considering the actual lack of quantification of such internal variables, this information would be essential for sports sciences, medicine, and ergonomics. This study also contributed to the advancement of scientific knowledge concerning hand control during power grip. A specially designed apparatus combining both an instrumented handle and a pressure map was used to record the forces at the hand/handle interface during maximal exertions. Data were processed such that the forces exerted on 25 hand anatomical areas were determined. Joint angles of the five fingers and the wrist were also computed from synchronized kinematic measurements. These processed data were used as input of a hand/wrist biomechanical model, which includes 23 degrees of freedom and 42 muscles to estimate muscle and joint forces. Greater forces were applied on the distal phalanges of the long fingers compared with the middle and the proximal ones. Concomitantly, high solicitations were observed for FDP muscles. A large cocontraction level of extensor muscles was also estimated by the model and confirmed previously reported activities and injuries of extensor muscles related to the power grip. Quantifying hand internal loadings also resulted in new insights into the thumb and the wrist biomechanics. Output muscle tension ratios were all in smaller ranges than the ones reported in the literature. Including wrist and finger interactions in this hand model provided new quantification of muscle load sharing, cocontraction level, and biomechanics of the hand. Such information could complete future investigations concerning handle ergonomics or pathomechanisms of hand musculoskeletal disorders.
Juan G Bonitch-Góngora
Full Text Available The grip is an important technical and tactical aspect through which the judokas dominate the adversary, hindering the application of appropriate techniques and favoring their own attack. The judokas must have high levels of isometric force and endurance to this type of force on the gripping muscles of the forearms, as one of the key aspects for success. This article reviews the grip muscular strength and endurance profiles of judokas of different groups (gender, age and competitive level. In general, the peak isometric strength of elite judokas has not changed in the last 40 years and is similar to that reached by non-elite judokas or even registered in large populations. This indicate that the evaluation of the isometric hand grip endurance may be a more relevant parameter than the peak isometric force in judokas, as during the bouts the grip must be maintained for relatively long periods of time and the maximum force cannot be maintained for long. However there are few studies on the ability to resist successive isometric handgrip stress in judokas.
Shang, X.; Veldhuis, R.N.J.
Secure Grip1 focuses on the development of a hand-grip pattern recognition system, as part of a smart gun. It is intended for use by the police. We collected the hand-grip data from police officers in three sessions in a row with time intervals in between. If data for training and testing come from
Zakariya M P
Full Text Available Background: Grip and pinch strength are commonly employed indices of strength used in hand evaluations. Pinch grip and power grip strengths are used as indices of strength in hand therapy assessments. For all professions grip strength is an important criterion to be successful in their profession. Such phenomena may be explained by differences in nature of work, working environment, and objects workers handle. Method: 200 healthy subjects, satisfying the selection criteria were included and assessed with standardized procedure for power grip and pinch grip (lateral pinch, pad-pad, and tip-tip strength. They were divided in four groups, 50 group each according to profession i.e. medical surgeons, dentist, physiotherapists and nurses. Results: The mean power grip strength shows highly significant difference between medical vs. dental (p>0.01 and medical vs. physiotherapy group (p> 0.05 .The mean lateral pinch strength shows there is highly significant difference (p< 0.001 between dental vs. nursing profession and dental vs. physiotherapy group. No significant difference among other groups. The mean pad-pad pinch strength shows there is significant difference between dental vs. nursing (p< 0.05 and dental vs physiotherapy group (p< 0.05. The mean Tip-Tip pinch strength shows there is significant difference between dental vs nursing profession(p< 0.05 and dental vs. physiotherapy(p< 0.05. No significant different among other groups. Conclusion: Surgeons have highest power grip strength followed by Nursing, Physiotherapy and Dental professionals. Dentists have the maximum pinch strength in all three positions, followed by Surgeons, Nurses and Physiotherapists. Surgeons have maximum pinch strength next to Dentists.
Full Text Available The present study was motivated by a theory, which proposes that speech includes articulatory gestures that are connected to particular hand actions. We hypothesized that certain articulatory gestures would be more associated with the precision grip than with the power grip, and vice versa. In the study, the participants pronounced a syllable and performed simultaneously a precision or power grip that was theorized to be either congruent or incongruent with the syllable. Relatively fast precision grip responses were associated with articulatory gestures in which the tip of the tongue contacted the alveolar ridge ([te] or the aperture of the vocal tract remained small ([hi], as well as gestures that required lip protrusion ([pu]. In contrast, relatively fast power grip responses were associated with gestures that were produced by moving the back of the tongue against the velum ([ke] or in which the aperture of the vocal tract remained large ([hα]. In addition to demonstrating that certain articulatory gestures are systematically connected to different grip types, the study may shed some light on discussion concerning sound symbolism and evolution of speech.
Full Text Available Amputee soccer is one of the types of soccer designed for the disabled, especially those who have undergone amputations, as well as those with extremity dysfunction. The objective of the study was to find the relationship between hand grip strength and sprint time in amputee soccer players. Thirteen field amputee soccer players participated in the study. A SAEHAN hydraulic hand dynamometer manufactured by Jamar was used for hand grip strength measurements. The sprint running test was conducted over a distance of 30 m. The Fusion Smart Speed System was employed for running time measurements. No statistically significant relationships were found between hand grip strength of the left or right hand, and sprint times over 1, 5, 10, 15, 20, 25 and 30 m. Analysis of the running velocity curve of the subjects showed an interesting profile characterized by a 15 meter-long acceleration phase and a significant velocity increase over a distance of 20 – 25 m. The study suggests that there is no relationship between hand grip strength and sprint effectiveness in amputee soccer players. The specificity of locomotion with the use of elbow crutches among elite Polish amputee soccer players probably accounts for the profile of the sprint velocity curve. Extension of the acceleration phase in the sprint run and a velocity increase in the subsequent part of the run were observed.
Erkol İnal, Esra; Çarlı, Alparslan Bayram; Çanak, Sultan; Aksu, Oğuzhan; Köroğlu, Banu Kale; Savaş, Serpil
Hyperthyroidism is a pathologic condition in which the body is exposed to excessive amounts of circulating thyroid hormones. Skeletal muscle is one of the major target organs of thyroid hormones. We evaluated hand grip strength and function in patients with overt hyperthyroidism. Fifty-one patients newly diagnosed with hyperthyroidism and 44 healthy controls participated in this study. Age, height, weight, and dominant hand of all participants were recorded. The diagnosis of hyperthyroidism was confirmed by clinical examination and laboratory tests. Hand grip strength was tested at the dominant hand with a Jamar hand dynamometer. The grooved pegboard test (PGT) was used to evaluate hand dexterity. The Duruöz Hand Index (DHI) was used to assess hand function. No significant differences were found in terms of clinical and demographic findings between the patients with hyperthyroidism and healthy controls (p > 0.05). Significant differences were found between the patients with hyperthyroidism and healthy controls regarding PGT and DHI scores (p Hyperthyroidism seemed to affect hand dexterity and function more than hand grip strength and seemed to be associated with reduced physical function more than muscle strength. This may also indicate that patients with hyperthyroidism should be evaluated by multidisplinary modalities.
Norton, William E.; Belcher, Jewell B.; Vest, Thomas W.; Carden, James R.
Prosthetic hand developed for amputee who retains significant portion of forearm. Outer end of device is end effector including two fingers, one moved by rotating remaining part of forearm about its longitudinal axis. Main body of end effector is end member supporting fingers, roller bearing assembly, and rack-and-pinion mechanism. Advantage of rack-and-pinion mechanism enables user to open or close gap between fingers with precision and force.
Enders, Leah R; Seo, Na Jin
The effect of sensory deficits on power grip force from individual phalanges was examined. The authors found that stroke survivors with sensory deficits (determined by the Semmes-Weinstein monofilament test) gripped with phalanx force directed more tangential to the object surface, than those without, although both groups had similar motor deficits (Chedoke-McMaster and Fugl-Meyer), grip strength, and skin friction. Altered grip force direction elevates risk of finger slippage against the object thus grip loss/object dropping, hindering activities of daily living. Altered grip force direction was associated with altered muscle activation patterns. In summary, the motor impairment level alone may not describe hand motor control in detail. Information about sensory deficits helps elucidate patients' hand motor control with functional relevance.
Aadahl, Mette; Beyer, Nina; Linneberg, Allan
To assess muscular fitness by hand grip strength (HGS) and lower limb extension power (LEP) and to explore associations with age, leisure time physical activity (LTPA) and body composition.......To assess muscular fitness by hand grip strength (HGS) and lower limb extension power (LEP) and to explore associations with age, leisure time physical activity (LTPA) and body composition....
Full Text Available Moa Jeong,1 Hyung Koo Kang,1 Pamela Song,2 Hye Kyeong Park,1 Hoon Jung,1 Sung-Soon Lee,1 Hyeon-Kyoung Koo1 1Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, 2Department of Neurology, Ilsan Paik Hospital, Inje University College of Medicine, Goyang, Republic of Korea Purpose: Hand grip strength (HGS is a simple way of predicting the risk of cardiovascular disease and all-cause mortality in the general population. However, the practical significance of grip strength in patients with COPD is uncertain. The aim of this study was to compare HGS between subjects with and without COPD and to evaluate its clinical relevance in patients with COPD by using a national survey.Methods: Data were collected from the Korean National Health and Nutrition Examination Survey. The study included 421 adults with COPD and 2,542 controls who completed questionnaires, spirometry, and a HGS test. HGS was compared between subjects with and without COPD, and the association between grip strength, lung function, and quality of life (QoL was evaluated.Results: The mean HGS was 33.3±9.1 kg in the COPD group and 29.9±9.5 kg in the non-COPD group; adjusted HGS was 30.9±0.33 kg and 30.9±0.11 kg, respectively (P=0.99. HGS was not related to forced vital capacity (β=0.04, P=0.70 or forced expiratory volume in 1 second (β=0.11, P=0.24 in multivariable analysis. HGS was independently associated with the EQ-5D index, but the relationship was stronger in the COPD group (β=0.30, P<0.001 than in the non-COPD group (β=0.21, P<0.001. The results were similar for each component of the EQ-5D, including mobility (β=-0.25, P<0.001, daily activity (β=-0.19, P=0.01, pain/discomfort (β=-0.32, P<0.001, and anxiety/depression (β=-0.16, P=0.01.Conclusion: HGS was not different between subjects with and without COPD, but was associated with QoL – including mobility, daily activity, pain/discomfort, and anxiety/depression – in patients with COPD. The
Sallinen, Janne; Stenholm, Sari; Rantanen, Taina; Heliövaara, Markku; Sainio, Päivi; Koskinen, Seppo
To determine optimal hand-grip strength cut points for likelihood of mobility limitation in older people and to study whether these cut points differ according to body mass index (BMI). Cross-sectional analysis of data. Data collected in the Finnish population-based Health 2000 Survey. One thousand eighty-four men and 1,562 women aged 55 and older with complete data on anthropometry, hand-grip strength and self-reported mobility. Mobility limitation was defined as difficulty walking 0.5 km or climbing stairs. Receiver operating characteristic analysis was used to estimate hand-grip strength cut points for likelihood of mobility limitation. The overall hand-grip strength cut points for likelihood of mobility limitation were 37 kg (sensitivity 62%; specificity 76%) for men and 21 kg (sensitivity 67%; specificity 73%) for women. The effect of the interaction between hand-grip strength and BMI on mobility limitation was significant in men (P=.02), but no such interaction was observed in women (P=.16). In men, the most-optimal cutoff points were 33 kg (sensitivity 73%; specificity 79%) for normal-weight men, 39 kg (sensitivity 67%; specificity 71%) for overweight men, and 40 kg (sensitivity 57%; specificity 68%) for obese men. In women, BMI-specific hand-grip strength cutoff values was not markedly more accurate than the overall cutoff value. The hand-grip strength test is a useful tool to identify persons at risk of mobility limitation. In men, hand-grip strength cut points for mobility increased with BMI, whereas in women, only one hand-grip strength threshold was identified. © 2010, Copyright the Authors. Journal compilation © 2010, The American Geriatrics Society.
Petersen, Inge; Pedersen, Nancy L; Rantanen, Taina;
and Environment across Multiple Studies consortium. Growth curve parameters were estimated for same-sex pairs, aged 34-99 (N = 10,681). Fisher's test for mixture distribution of within-monozygotic twin-pair differences (N = 1724) was performed on growth curve parameters. We observed significant gene......-environment interaction on grip strength trajectories. Finally, we compared the variability of within-pair differences of growth curve parameters by APOE haplotypes. Though not statistically significant, the results suggested that APOE ɛ2ɛ2/ɛ2ɛ3 haplotypes might buffer environmental influences on grip strength...
Débora Rocha Oliveira
Full Text Available Objective: To evaluate and compare the effectiveness of different methods used for nutritional assessment of outpatients who had hemiplegic stroke. Methods: A cross-section study with adult and elderly patients of both genders enrolled in a rehabilitation center. The analyzed variables were anthropometric measurements, bioelectrical impedance, hand grip strength and thickness of the adductor pollicis muscle. The Pearson χ2 test was used to check the association between variables with a significance level of α = 5%. Results: When evaluating the association between indicators of muscle mass, it was observed that the hand grip strength in both genders was positively correlated with arm muscle circumference (p = 0.0196 and lean mass (p = 0.0002. Fat mass measured by the bioelectrical impedance method already showed a significant inverse relationship with the grip (r = -0.3879. The thickness of the adductor pollicis muscle showed significant association with lean mass (p = 0.0052 and hand grip (p = 0.0024. Conclusion: In this study, the hand grip strength and thickness of the adductor pollicis muscle were well correlated with measurements determined by anthropometry and bioimpedance. The results show the applicability of grip strength and thickness of the adductor pollicis muscle in clinical practice as nutritional assessment methods for this population, especially elderly patients, since they detect functional changes not captured by other parameters in the short term and are important for early identification of risk nutrition.
Ye, Yu; Ma, Le; Yan, Tiebin; Liu, Huihua; Wei, Xijun; Song, Rong
The aim of this study is to investigate quantitative outcome measurements of hand motor performance for subjects after mild to moderate stroke using grip control tasks and characterize abnormal flexion synergy of upper extremities after stroke. A customized dynamometer with force sensors was used to measure grip force and calculate rotation torque during the sub-maximal grip control tasks. The paretic and nonpartic sides of eleven subjects after stroke and the dominant sides of ten healthy persons were tested. Their maximal voluntary grip force was measured and used to set sub-maximal grip control tasks at three different target force levels. Force control ability was characterized by the maximal grip force, mean force percentage, coefficient of variation (CV), target deviation ratio (TDR), and rotation torque ratio (RTR). The motor impairments of subjects after stroke were also evaluated using the Fugl-Meyer assessment for upper extremity (FMA-UE) and Wolf Motor Function Test (WMFT). Maximal grip force of the paretic side was significantly reduced as compared to the nonparetic side and the healthy group, while the difference of maximal grip force between the nonparetic side and the healthy group was not significant. TDR and RTR increased for all three groups with increasing target force level. There were significant differences of CV, TDR and RTR between the paretic side and the healthy group at all the force levels. CV, TDR and RTR showed significant negative correlations with FMA-UE and WMFT at 50% of maximum grip force. This study designed a customized dynamometer together with an innovative measurement, RTR, to investigate the hand motor performance of subjects after mild to moderate stroke during force control tasks. And stroke-induced abnormal flexion synergy of wrist and finger muscles could be characterized by RTR. This study also identified a set of kinetic parameters which can be applied to quantitatively assess the hand motor function of subjects after
Kim, Ji Young; Kim, Seong Yeol
[Purpose] Many assumptions have been made about taping and several studies have considered tape application methods; however, the true effect of taping on muscle strength remains unclear. Most previous studies compared application techniques using Kinesio tape (KT), but studies that compared muscle strength using non-elastic tape (NT) are limited. Moreover, no studies have applied KT and NT in the same way to assess grip strength in normal subjects. The purpose of this study was to evaluate the immediate effect of application of two tapes with different elastic properties on maximal grip strength in healthy adults. [Subjects and Methods] Twenty healthy adults were divided into two groups (KT and NT). Maximal grip strength was measured with a dynamometer. Forearm extensor muscles of the dominant hand were then taped and subjects were immediately asked to perform hand grip movement with maximum strength in the same standardized manner. [Results] In the KT group, maximal grip strength was significantly increased compared to the initial value; however, in the NT group, there was no significant difference in maximal grip strength. [Conclusion] This study suggests that only Kinesio tape can increase maximal grip strength immediately after application on the extensor region of the forearm.
Kim, Ji Young; Kim, Seong Yeol
[Purpose] Many assumptions have been made about taping and several studies have considered tape application methods; however, the true effect of taping on muscle strength remains unclear. Most previous studies compared application techniques using Kinesio tape (KT), but studies that compared muscle strength using non-elastic tape (NT) are limited. Moreover, no studies have applied KT and NT in the same way to assess grip strength in normal subjects. The purpose of this study was to evaluate the immediate effect of application of two tapes with different elastic properties on maximal grip strength in healthy adults. [Subjects and Methods] Twenty healthy adults were divided into two groups (KT and NT). Maximal grip strength was measured with a dynamometer. Forearm extensor muscles of the dominant hand were then taped and subjects were immediately asked to perform hand grip movement with maximum strength in the same standardized manner. [Results] In the KT group, maximal grip strength was significantly increased compared to the initial value; however, in the NT group, there was no significant difference in maximal grip strength. [Conclusion] This study suggests that only Kinesio tape can increase maximal grip strength immediately after application on the extensor region of the forearm. PMID:27313372
Sridharan, Kousik Sarathy; Højlund, Andreas; Johnsen, Erik Lisbjerg
(MEG) from six PD patients performing hand gripping during DBS ON and medicated (levodopa, MED ON) conditions and from ten age-matched healthy controls. Participants performed isotonic contractions (hand gripping) with their right hand, and electromyography (EMG) was recorded from the extensor...... digitorum communis muscle with a belly-tendon montage. We calculated the mean-squared coherence between MEG and the rectified EMG signals. For each group and condition, we selected the maximum CMC value in the beta range (13-30 Hz) within the average of an a priori selection of nine left sensorimotor...
Guo, Beiyuan; Gan, Weide; Fang, Weining
Longitudinal acceleration comfort is one of the essential metrics used to evaluate the ride comfort of train. The aim of this study was to investigate the effectiveness of using hand grip force as a correlate of longitudinal acceleration comfort of rapid transit trains. In the paper, a motion simulation system was set up and a two-stage experiment was designed to investigate the role of the grip force on the longitudinal comfort of rapid transit trains. The results of the experiment show that the incremental grip force was linearly correlated with the longitudinal acceleration value, while the incremental grip force had no correlation with the direction of the longitudinal acceleration vector. The results also show that the effects of incremental grip force and acceleration duration on the longitudinal comfort of rapid transit trains were significant. Based on multiple regression analysis, a step function model was established to predict the longitudinal comfort of rapid transit trains using the incremental grip force and the acceleration duration. The feasibility and practicably of the model was verified by a field test. Furthermore, a comparative analysis shows that the motion simulation system and the grip force based model were valid to support the laboratory studies on the longitudinal comfort of rapid transit trains.
Roberts, Luke; Singhal, Girish; Kaliki, Rahul
We have designed a closed loop control system that adjusts the grasping force of a prosthetic hand based on the amount of object slip detected by an optical tracking sensor. The system was designed for the i-Limb (a multi-fingered prosthetic hand from Touch Bionics Inc.) and is comprised of an optical sensor embedded inside a silicone prosthetic glove and a control algorithm. In a proof of concept study to demonstrate the effectiveness of optical tracking in slip sensing, we record slip rate while increasing the weight held in the grasp of the hand and compare two cases: grip adjustment on and grip adjustment off. The average slip rate was found to be 0.314 slips/(s · oz) without grip adjustment and 0.0411 slips/(s · oz) with grip adjustment. This paper discusses the advantages of the optical approach in slip detection and presents the experiment and results utilizing the optical sensor and grip control algorithm.
Schreuders, Ton A R; Roebroeck, Marij E; Goumans, Janine; van Nieuwenhuijzen, Johan F; Stijnen, Theo H; Stam, Henk J
There is limited documentation of measurement error of grip and pinch force evaluation methods. The purposes of this study were (1) to determine indexes of measurement error for intraexaminer and interexaminer measurements of grip and pinch force in patients with hand injuries and (2) to investigate whether the measurement error differs between measurements of the injured and noninjured hands and between experienced and inexperienced examiners. The subjects were a consecutive sample of 33 patients with hand injuries who were seen in the Department of Rehabilitation Medicine of Erasmus MC-University Medical Center Rotterdam in the Netherlands. Repeated measurements were taken of grip and pinch force, with a short break of 2 to 3 minutes between sessions. For the grip force in 2 handle positions (distance between handles of 4.6 and 7.2 cm, respectively), tip pinch (with the index finger on top and the thumb below, with the other fingers flexed) and key pinch force (with the thumb on top and the radial side of the index finger below) data were obtained on both hands of the subjects by an experienced examiner and an inexperienced examiner. Intraclass correlation coefficients (ICCs), standard errors of measurement (SEMs), and associated smallest detectable differences (SDDs) were calculated and compared with data from previous studies. The reliability of the measurements was expressed by ICCs between .82 and .97. For grip force measurements (in the second handle position) by the experienced examiner, an SDD of 61 N was found. For tip pinch and key pinch, these values were 12 N and 11 N, respectively. For measurements by the inexperienced examiner, SDDs of 56 N for grip force and 13 N and 18 N for tip pinch and key pinch were found. Based on the SEMs and SDDs, in individual patients only relatively large differences in grip and pinch force measurements can be adequately detected between consecutive measurements. Measurement error did not differ between injured and
Friedman, Nizan; Chan, Vicky; Zondervan, Danny; Bachman, Mark; Reinkensmeyer, David J
People with stroke typically must perform much of their hand exercise at home without professional assistance as soon as two weeks after the stroke. Without feedback and encouragement, individuals often lose motivation to practice using the affected hand, and this disuse contributes to further declines in hand function. We developed the MusicGlove as a way to facilitate and motivate at home practice of hand movement. This low-cost device uses music as an interactive and motivating medium to guide hand exercise and to quantitatively assess hand movement recovery. It requires the user to practice functional movements, including pincer grip, key-pinch grip, and finger-thumb opposition, by using those movements to play different musical notes, played along to songs displayed by an interactive computer game. We report here the design of the glove and the results of a single-session experiment with 10 participants with chronic stroke. We found that the glove is well suited for use by people with an impairment level quantified by a Box and Blocks score of at least around 7; that the glove can be used to obtain a measure of hand dexterity (% of notes hit) that correlates strongly with the Box and Blocks score; and that the incorporation of music into training significantly improved both objective measures of hand motor performance and self-ratings of motivation for training in the single session.
Mohamad, M.; Mardan, N. H.; Ismail, S. S.
Aging is associated with a decline in cognitive and motor function. But, the relationships with motor performance are less well understood. In this study, functional magnetic resonance imaging (fMRI) was used to assess cortical activation in older adults. This study employed power grip task that utilised block paradigm consisted of alternate 30s rest and active. A visual cue was used to pace the hand grip movement that clenched a cylindrical rubber bulb connected with pressure pneumatic gauge that measure the pressure (Psi). The objective of this study is determined the brain areas activated during motor task and the correlation between percentage signal change of each motor area (BA 4 and 6) and hand grip pressure. Result showed there was a significant difference in mean percentage signal change in BA 4 and BA 6 in both hemispheres and negative correlation obtained in BA 4 and BA 6. These results indicate that a reduced ability in the motor networks contribute to age-related decline in motor performance.
Willems, Sara M; Wright, Daniel J.; Day, Felix R
Hand grip strength is a widely used proxy of muscular fitness, a marker of frailty, and predictor of a range of morbidities and all-cause mortality. To investigate the genetic determinants of variation in grip strength, we perform a large-scale genetic discovery analysis in a combined sample of 1...
Willems, Sara M.; Wright, D.J.; Day, Felix R.; Trajanoska, Katerina; Joshi, P.K.; Morris, John A.; Matteini, Amy M.; Garton, Fleur C.; Grarup, Niels; Oskolkov, Nikolay; Thalamuthu, Anbupalam; Mangino, Massimo; Liu, Jun; Demirkan, Ayse; Lek, Monkol; Xu, Liwen; Wang, Guan; Oldmeadow, Christopher; Gaulton, Kyle J.; Lotta, Luca A.; Miyamoto-Mikami, Eri; Rivas, Manuel A.; White, Tom; Loh, Po Ru; Aadahl, Mette; Amin, Najaf; Attia, John R.; Austin, Krista; Benyamin, Beben; Brage, Søren; Cheng, Yu Ching; Ciȩszczyk, Paweł; Derave, Wim; Eriksson, Karl Fredrik; Eynon, Nir; Linneberg, Allan; Lucia, Alejandro; Massidda, Myosotis; Mitchell, Braxton D.; Miyachi, Motohiko; Murakami, Haruka; Padmanabhan, Sandosh; Pandey, Ashutosh; Papadimitriou, Ioannis; Rajpal, Deepak K.; Sale, Craig; Schnurr, Theresia M.; Sessa, Francesco; Shrine, Nick; Tobin, Martin D.; Varley, Ian; Wain, Louise V.; Wray, Naomi R.; Lindgren, Cecilia M.; MacArthur, Daniel G.; Waterworth, Dawn M.; McCarthy, Mark I.; Pedersen, Oluf; Khaw, Kay Tee; Kiel, Douglas P.; Pitsiladis, Yannis; Fuku, Noriyuki; Franks, Paul W.; North, Kathryn N.; Duijn, Van C.M.; Mather, Karen A.; Hansen, Torben; Hansson, Ola; Spector, Tim D.; Murabito, Joanne M.; Richards, J.B.; Rivadeneira, Fernando; Langenberg, Claudia; Perry, John R.B.; Wareham, Nick J.; Scott, Robert A.; Oei, Ling; Zheng, Hou Feng; Forgetta, Vincenzo; Leong, Aaron; Ahmad, Omar S.; Laurin, Charles; Mokry, Lauren E.; Ross, Stephanie; Elks, Cathy E.; Bowden, Jack; Warrington, Nicole M.; Murray, Anna; Ruth, Katherine S.; Tsilidis, Konstantinos K.; Medina-Gómez, Carolina; Estrada, Karol; Bis, Joshua C.; Chasman, Daniel I.; Demissie, Serkalem; Enneman, Anke W.; Hsu, Yi Hsiang; Ingvarsson, Thorvaldur; Kähönen, Mika; Kammerer, Candace; Lacroix, Andrea Z.; Li, Guo; Liu, Ching Ti; Liu, Yongmei; Lorentzon, Mattias; Mägi, Reedik; Mihailov, Evelin; Milani, Lili; Moayyeri, Alireza; Nielson, Carrie M.; Sham, Pack Chung; Siggeirsdotir, Kristin; Sigurdsson, Gunnar; Stefansson, Kari; Trompet, Stella; Thorleifsson, Gudmar; Vandenput, Liesbeth; Velde, Van Der Nathalie; Viikari, Jorma; Xiao, Su Mei; Zhao, Jing Hua; Evans, Daniel S.; Cummings, Steven R.; Cauley, Jane; Duncan, Emma L.; Groot, De Lisette C.P.G.M.; Esko, Tonu; Gudnason, Vilmundar; Harris, Tamara B.; Jackson, Rebecca D.; Jukema, J.W.; Ikram, Arfan M.A.; Karasik, David; Kaptoge, Stephen; Kung, Annie Wai Chee; Lehtimäki, Terho; Lyytikäinen, Leo Pekka; Lips, Paul; Luben, Robert; Metspalu, Andres; Meurs, van Joyce B.; Minster, Ryan L.; Orwoll, Erick; Oei, Edwin; Psaty, Bruce M.; Raitakari, Olli T.; Ralston, Stuart W.; Ridker, Paul M.; Robbins, John A.; Smith, Albert V.; Styrkarsdottir, Unnur; Tranah, Gregory J.; Thorstensdottir, Unnur; Uitterlinden, Andre G.; Zmuda, Joseph; Zillikens, M.C.; Ntzani, Evangelia E.; Evangelou, Evangelos; Ioannidis, John P.A.; Evans, David M.; Ohlsson, Claes
Hand grip strength is a widely used proxy of muscular fitness, a marker of frailty, and predictor of a range of morbidities and all-cause mortality. To investigate the genetic determinants of variation in grip strength, we perform a large-scale genetic discovery analysis in a combined sample of 195,
Zariffa, José; Steeves, John D
The complexity of hand function is such that most existing upper limb rehabilitation robotic devices use only simplified hand interfaces. This is in contrast to the importance of the hand in regaining function after neurological injury. Computer vision technology has been used to identify hand posture in the field of Human Computer Interaction, but this approach has not been translated to the rehabilitation context. We describe a computer vision-based classifier that can be used to discriminate rehabilitation-relevant hand postures, and could be integrated into a virtual reality-based upper limb rehabilitation system. The proposed system was tested on a set of video recordings from able-bodied individuals performing cylindrical grasps, lateral key grips, and tip-to-tip pinches. The overall classification success rate was 91.2%, and was above 98% for 6 out of the 10 subjects. © 2011 IEEE
Full Text Available Grasping is a highly complex movement that requires the coordination of a number of hand joints and muscles. Previous studies showed that spinal premotor interneurons (PreM-INs in the primate cervical spinal cord have divergent synaptic effects on hand motoneurons and that they might contribute to hand-muscle synergies. However, the extent to which these PreM-IN synaptic connections functionally contribute to modulating hand-muscle activity is not clear. In this paper, we explored the contribution of spinal PreM-INs to hand-muscle activation by quantifying the synaptic linkage (SL and functional linkage (FL of the PreM-INs with hand-muscle activities. The activity of 23 PreM-INs was recorded from the cervical spinal cord (C6–T1, with EMG signals measured simultaneously from hand and arm muscles in two macaque monkeys performing a precision grip task. Spike-triggered averages (STAs of rectified EMGs were compiled for 456 neuron–muscle pairs; 63 pairs showed significant post-spike effects (i.e., SL. Conversely, 231 of 456 pairs showed significant cross-correlations between the IN firing rate and rectified EMG (i.e., FL. Importantly, a greater proportion of the neuron–muscle pairs with SL showed FL (43/63 pairs, 68% compared with the pairs without SL (203/393, 52%, and the presence of SL was significantly associated with that of FL. However, a significant number of pairs had SL without FL (SL∩!FL, n = 20 or FL without SL (!SL∩FL, n = 203, and the proportions of these incongruities exceeded the number expected by chance. These results suggested that spinal PreM-INs function to significantly modulate hand-muscle activity during precision grip, but the contribution of other neural structures is also needed to recruit an adequate combination of hand-muscle motoneurons.
Bahat, Gulistan; Tufan, Asli; Ozkaya, Hilal; Tufan, Fatih; Akpinar, Timur Selçuk; Akin, Sibel; Bahat, Zumrut; Kaya, Zuleyha; Kiyan, Esen; Erten, Nilgün; Karan, Mehmet Akif
Adverse-outcomes related to sarcopenia are mostly mentioned as physical disability. As the other skeletal muscles, respiratory muscles may also be affected by sarcopenia. Respiratory muscle strength is known to affect pulmonary functions. Therefore, we aimed to investigate the relations between extremity muscle strength, respiratory muscle strengths and spirometric measures in a group of male nursing home residents. Among a total of 104 male residents, residents with obstructive measures were excluded and final study population was composed of 62 residents. Mean age was 70.5 ± 6.7 years, body mass index: 27.7 ± 5.3 kg/m2 and dominant hand grip strength: 29.7 ± 6.5 kg. Hand grip strength was positively correlated with maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) (r = 0.35, p strength; among spirometric measures only parameter significantly related to grip strength was peak cough flow (PCF). The association of PCF with grip strength disappeared when MIP alone or "MIP and MEP" were included in the regression analysis. In the latter case, PCF was significantly associated only with MIP. We found peripheric muscle strength be associated with MIP and PCF but not with MEP or any other spirometric parameters. The relation between peripheral muscle strength and PCF was mediated by MIP. Our findings suggest that sarcopenia may affect inspiratory muscle strength earlier or more than the expiratory muscle strength. Sarcopenia may cause decrease in PCF in the elderly, which may stand for some common adverse respiratory complications.
Bruch, Juliana Paula; Álvares-DA-Silva, Mário Reis; Alves, Bruna Cherubini; Dall'alba, Valesca
Hepatitis C is a liver disease that causes significant changes in metabolism, and also has an impact on nutritional status. To evaluate the nutritional status and cardiovascular risk in patients with chronic hepatitis C. This cross-sectional study investigated 58 patients with chronic hepatitis C, non-cirrhotic and were not under active pharmacological treatment. Patients with significant alcohol consumption (greater than 10 g ethanol/day) were excluded. Patients underwent nutritional assessment through anthropometric measurements and functional assessment using hand grip strength by dynamometry. The physical activity was assessed using the International Physical Activity Questionnaire. Patients also underwent clinical and laboratory evaluation. Cardiovascular risk was calculated by the Framingham score. The mean age of patients was 51.6±9.7 years, 55.2% were female, and 79.3% had genotype 1. The most prevalent degree of fibrosis was F1 (37.9%) followed by F2 (27.6%) and F3 (1.7%). The prevalence of overweight/obesity considering the body mass index was 70.7%. However, 57.7% of men and 68.8% of women were considered malnourished according to hand grip strength. These patients also had waist circumference (93.5±10.7 cm) and neck circumference (37.0±3.6 cm) high. Almost 60% of patients were considered sedentary or irregularly active. In relation to cardiovascular risk, 50% of patients had high risk of suffering a cardiovascular event within 10 years. Although most patients with hepatitis C presented overweight, associated with high cardiovascular risk, they also have reduced functional capacity, indicative of protein-caloric commitment. Therefore, body mass index can not be considered the only method of assessment for nutritional diagnosis of patients with liver disease. Adopting methods such as hand grip strength can be important for a better understanding of nutritional status of these patients.
Asmaa A. Abo Nour; Saleh, Muhammad G.; Emam H. Elnagmy
Background: hemiparetic children usually tend to avoid the use of their impaired arm and are remarkably tend to perform inherently bimanual tasks of daily living with the less impaired arm only rather than with both arms. In fact, these children actually may have never learned to use their impaired arm for certain motor tasks or may only use it in the simplest manner, so the purpose of the study was to determine the impact of combining HABIT and mirror therapy on hand grip in hemiparetic chil...
Siti Nur Baait Biniti Mohd Sokran
Full Text Available Background: Hand grip strength (HGS is a reliable indicator of peripheral muscle strength. Although, numerous studies have investigated the strength of hand grip; little attention has been given to coronary artery disease (CAD patients, exploring the relationship between HGS and myocardial oxygen consumption (MVO2 index. The current study aimed to evaluate the interaction between HGS and MVO2 index findings before and after cardiac surgery. Methods: Twenty-seven patients with CAD had HGS were assessed using handheld dynamometer. HGS for each hand were documented. MVO2 index was assessed using rate pressure product (RPP, which is the product of the heart rate (HR and systolic blood pressure (SBP. Repeated measures MANOVA were carried out to estimate the interaction between both hands HGS and MVO2 index before and after surgery. Results: There was significant interactions (P<0.001 for both HGS dominant and non-dominant with large effect sizes (HGS dominant×MVO2 index: hp2=0.44; HGS dominant×RPP: hp2=0.49. This signifies that peripheral muscle strength of the upper limb (HGS dominant and non-dominant had different effects on MVO2 index before and after surgery. The interaction graph shows that the increase in MVO2 index after surgery was significantly greater for peripheral muscle strength of the dominant hand when compared to non-dominant. Conclusion: Patients with CAD had interactions between HGS and oxygen consumption before and after surgery. Hence, HGS might be used as a predictor to assess oxygen consumption among cardiac patients.
Fattorini, L; Tirabasso, A; Lunghi, A; Di Giovanni, R; Sacco, F; Marchetti, E
The purpose of this paper is to evaluate the muscular activation of the forearm, with or without vibration stimuli at different frequencies while performing a grip tasks of 45s at various level of exerted force. In 16 individuals, 9 females and 7 males, the surface electromyogram (EMG) of extensor carpi radialis longus and the flexor carpi ulnari muscles were assessed. At a short latency from onset EMG, RMS and the level of MU synchronization were assessed to evaluate the muscular adaptations. Whilst a trend of decay of EMG Median frequency (MDFd) was employed as an index of muscular fatigue. Muscular tasks consists of the grip of an instrumented handle at a force level of 20%, 30%, 40%, 60% of the maximum voluntary force. Vibration was supplied by a shaker to the hand in mono-frequential waves at 20, 30, 33 and 40Hz. In relation to EMG, RMS and MU synchronization, the muscular activation does not seem to change with the superimposition of the mechanical vibrations, on the contrary a lower MDFd was observed at 33Hz than in absence of vibration. This suggests an early muscular fatigue induced by vibration due to the fact that 33Hz is a resonance frequency for the hand-arm system.
Badwe, A. N.; Latti, Ramchandra Girimalappa
Objective: To study the effect of isometric hand grip exercise at 20% on normotensive, treated hypertensive, and non treated hypertensive in supine position, and at 300 and 600 head up tilt.Material and Methods: After recording heart rate in supine position, isometric hand grip exercise at 20% was conducted for 2 minutes with dominant hand and heart rate was recorded for 1 minute in all subjects after end of the exercise. The same maneuver was repeated before head up tilt in supine position a...
Full Text Available Abstract Background Objective assessment of motor function is frequently used to evaluate outcome after surgical treatment of carpal tunnel syndrome (CTS. However a range of outcome measures are used and there appears to be no consensus on which measure of motor function effectively captures change. The purpose of this systematic review was to identify the methods used to assess motor function in randomized controlled trials of surgical interventions for CTS. A secondary aim was to evaluate which instruments reflect clinical change and are psychometrically robust. Methods The bibliographic databases Medline, AMED and CINAHL were searched for randomized controlled trials of surgical interventions for CTS. Data on instruments used, methods of assessment and results of tests of motor function was extracted by two independent reviewers. Results Twenty-two studies were retrieved which included performance based assessments of motor function. Nineteen studies assessed power grip dynamometry, fourteen studies used both power and pinch grip dynamometry, eight used manual muscle testing and five assessed the presence or absence of thenar atrophy. Several studies used multiple tests of motor function. Two studies included both power and pinch strength and reported descriptive statistics enabling calculation of effect sizes to compare the relative responsiveness of grip and pinch strength within study samples. The study findings suggest that tip pinch is more responsive than lateral pinch or power grip up to 12 weeks following surgery for CTS. Conclusion Although used most frequently and known to be reliable, power and key pinch dynamometry are not the most valid or responsive tools for assessing motor outcome up to 12 weeks following surgery for CTS. Tip pinch dynamometry more specifically targets the thenar musculature and appears to be more responsive. Manual muscle testing, which in theory is most specific to the thenar musculature, may be more
Takei, Tomohiko; Seki, Kazuhiko
Grasping is a highly complex movement requiring coordination of a number of hand joints and muscles. In contrast to cortical descending systems, the contribution of the subcortical system for coordinating this higher degree of freedom is largely unknown. Here we explore how spinal interneurons (INs) contribute to the coordination of hand muscles by recording their activity from the cervical spinal cord (C5-T1) simultaneously with electromyographic (EMG) activity from hand and arm muscles in three monkeys performing a precision grip task. Spike-triggered averages of the rectified EMGs were compiled for 255 neurons (4821 neuron-muscle pairs). Twenty-six neurons produced 68 significant postspike effects in hand and arm muscles and were identified as premotor interneurons (PreM-INs), which presumably have relatively direct synaptic effects on spinal motoneurons. The majority of the PreM-INs (22/26 neurons) produced postspike effects in finger muscles (intrinsic and extrinsic hand muscles) compared with wrist (9/26 neurons) and elbow muscles (1/26 neurons). The effects in finger muscles were mostly facilitative [postspike facilitations (PSFs), 19/22 neurons], and few had suppressive effects (postspike suppressions, 3/22 neurons). Moreover, PreM-INs produced more divergent PSFs in intrinsic hand muscles (2.5 ± 1.9 muscles/neuron) than in wrist muscles (1.2 ± 0.4 muscles/neurons). We conclude that spinal PreM-INs produce divergent facilitations preferentially in intrinsic hand muscles. These results suggest that spinal interneurons contribute to the control of hand grasping in primates by combining and coordinating multiple finger muscles.
Hashemi Oskouei, Alireza; Paulin, Michael G; Carman, Allan B
Surface electromyography (EMG) is widely used to evaluate forearm muscle function and predict hand grip forces; however, there is a lack of literature on its intra-session and inter-day reliability. The aim of this study was to determine reliability of surface EMG of finger and wrist flexor muscles across varying grip forces. Surface EMG was measured from six forearm flexor muscles of 23 healthy adults. Eleven of these subjects undertook inter-day test-retest. Six repetitions of five randomized isometric grip forces between 0% and 80% of maximum force (MVC) were recorded and normalized to MVC. Intra- and inter-day reliability were calculated through the intraclass correlation coefficient (ICC) and standard error of measurement (SEM). Normalized EMG produced excellent intra-session ICC of 0.90 when repeated measurements were averaged. Intra-session SEM was low at low grip forces, however, corresponding normalized SEM was high (23-45%) due to the small magnitude of EMG signals. This may limit the ability to evaluate finer forearm muscle function and hand grip forces in daily tasks. Combining EMG of functionally related muscles improved intra-session SEM, improving within-subject reliability without taking multiple measurements. Removing and replacing electrodes inter-day produced poor ICC (ICC < 0.50) but did not substantially affect SEM.
Asmaa A. Abo Nour
Full Text Available Background: hemiparetic children usually tend to avoid the use of their impaired arm and are remarkably tend to perform inherently bimanual tasks of daily living with the less impaired arm only rather than with both arms. In fact, these children actually may have never learned to use their impaired arm for certain motor tasks or may only use it in the simplest manner, so the purpose of the study was to determine the impact of combining HABIT and mirror therapy on hand grip in hemiparetic children. Methods: A total of 30 hemiparetic children divided randomly into two groups (A and B of equal number, (N of each =15. Eligibility criteria to our study were age ranged from 4-8 years, ability to score more than 50 % of grasps and associated domains of quality of upper extremity skills test (QUEST and grade 2 in manual ability classification system (MACS, assessment done by baseline hand held dynamometer for hand palmar & pinch grasp strength (in pounds at start (0 week, reassessed at 4 & 8 weeks. The treatment protocol for two groups include: 2 months total time, 3 sessions\\ week, 1.5 hour\\session. Children in study group (A received selected occupational therapy program with modified mirror apparatus while children in control group (B Children received the same occupational therapy program as in study group but without modified mirror apparatus. Results: there is significant improvement in both groups when comparing the pre and post I & II treatment mean values. However comparing the post treatment results of both groups were statistically non-significant. Conclusion: This study confirmed that combining mirror therapy and HABIT is effective in improving hand function.
Benaglia, P G; Franchignoni, F; Ferriero, G; Zebellin, G; Sartorio, F
Strength measurement of the hand grip is at the core of most protocols of functional assessment of the upper limb and in rehabilitation plays a major role in the analysis of treatment efficacy and patients' occupational ability. The aims of this study were to: a) verify the repeatability of strength measurements made during performance of the hand grip and three types of pinch, carried out under isometric and isokinetic conditions; b) compare maximal isometric strength with the corresponding isokinetic value for each of the manoeuvres studied; c) investigate the correlations between the strength expressed in the different manoeuvres, under both isometric and isokinetic conditions. We studied 14 voluntary subjects over three sessions conducted at 48-hr intervals, employing a computerized isokinetic dynamometer Lido WorkSet equipped with device N(o) 21 for the study of pinch (lateral pinch, pulp pinch, chuck pinch) and device N(o) 52 for the grip study. Isometric contractions resulted stronger than isokinetic ones, and the hand grip was found to be the manoeuvre able to produce most strength. The repeatability of each strength measurement test over the three days was high (Intraclass Correlation Coefficients: 0.89-0.93). Correlations between the isometric and isokinetic performance for each of the manoeuvres examined were always high (Pearson's r coefficients: 0.89-0.95) as were those between the different manoeuvres, whether performed in isometric or isokinetic modality (r: 0.60-0.94).
Kauê Carvalho de Almeida Lima
involving object manipulation. The aim of the study was to compare the performance of diabetic individual without diagnosis of neuropathy with non-diabetic healthy individuals in manipulation task and their maximum power grip strength. Thirteen diabetic individuals without peripheral neuropathy diagnosis (48.6±11.51 years-old; 79.9±10.88 kg; 1.68±0.09 m and 13 healthy age- and gender-matched controls (48.5±10.09 years-old; 76.44±11.79 kg; 1.69±0.1 m participated in the study. Hand cutaneous sensitivity was assessed by the Semmes-Weinstein monofilaments examination (SWME followed by the application of three tests commonly used to assess hand function: Jebsen-Taylor hand function test (JTHFT, nine hole peg test (9HPT and maximum power grip strength test (GSmax. The results of SWME revealed that eight diabetic individuals presented normal cutaneous sensitivity and five showed mild sensory losses, but that was not enough to characterize them as neuropathic diabetics. Regarding the hand function tests, the results revealed no difference between diabetic individuals and healthy controls in any of the tests performed (diabetic individuals and controls - JHHFT: 26.15±3.06 and 25.78±1.29 s; 9HPT: 15.33±1.35 and 15.48±2.39 s; GSmax: 41.15±10.59 and 43.69±12.59 kgf. Therefore, we conclude that diabetic individuals without neuropathy show no hand function impairment, as well as no reduction in the maximum power grip strength.
Geevasinga, Nimeshan; Menon, Parvathi; Kiernan, Matthew C; Vucic, Steve
While task-dependent changes in motor cortical outputs have been previously reported, the issue of whether such changes are specific for complex hand tasks remains unresolved. The aim of the present study was to determine whether cortical inhibitory tone and cortical output were greater during precision grip and power grip. Motor cortex excitability was undertaken by using the transcranial magnetic stimulation threshold tracking technique in 15 healthy subjects. The motor-evoked potential (MEP) responses were recorded over the abductor pollicis brevis (APB), with the hand in the following positions: (1) rest, (2) precision grip and (3) power grip. The MEP amplitude (MEP amplitude REST 23.6 ± 3.3%; MEP amplitude PRECISION GRIP 35.2 ± 5.6%; MEP amplitude POWER GRIP 19.6 ± 3.4%, F = 2.4, P < 0.001) and stimulus-response gradient (SLOPEREST 0.06 ± 0.01; SLOPEPRCISION GRIP 0.15 ± 0.04; SLOPE POWER GRIP 0.07 ± 0.01, P < 0.05) were significantly increased during precision grip. Short interval intracortical inhibition (SICI) was significantly reduced during the precision grip (SICI REST 15.0 ± 2.3%; SICI PRECISION GRIP 9.7 ± 1.5%, SICI POWER GRIP 15.9 ± 2.7%, F = 2.6, P < 0.05). The present study suggests that changes in motor cortex excitability are specific for precision grip, with functional coupling of descending corticospinal pathways controlling thumb and finger movements potentially forming the basis of these cortical changes.
Yefta Daniel Bastiana
Full Text Available In previous studies, duration of hand exercises in patients with rheumatoid arthritis (RA had widely varying ranges, from 3 weeks to 4 months. An experimental study was conducted to evaluate the effect of range of motion (ROM and muscle strengthening exercises for 6 weeks on grip strength and hand function in RA patients. Seventeen patients with chronic RA were randomly assigned to a treatment group and a control group. The treatment group (n=8 was given muscle strengthening exercises and heat therapy using paraffin baths 3 times a week at the hospital and ROM exercises once a day at home for 6 weeks. The control group (n=9 was given only paraffin baths 3 times a week. After 6 weeks, there were significant differences in hand function (p=0.003, right and left grip strength (p=0.000 and p=0.001 and ROM in the interventional group only. ROM and isometric strengthening exercises significantly improved grip strength and hand function in patients with RA, while no impact was found when the patients were given paraffin baths only. In view of the small size of the study population, there is a need for further studies with larger populations.
The GRIPS (Geothermal Resources Impact Projection Study) Commission was established by a Joint Powers Agreement between the California Counties of Lake, Mendocino, Napa, and Sonoma. The objectives of GRIPS are primarily to develop and use a cooperative environmental data collection and use system including natural, social, and economic considerations to facilitate their independent decisions and those of State and Federal agencies related to the environmental effects of geothermal development. This GRIPS Plan was prepared from a wide range of studies, workshops, and staff analyses. The plan is presented in four parts: summary and introduction; environmental data status report; planned programs; and budget. (MHR)
Full Text Available Objective: Hospitalization process causes a variety of physical problems. The decrease of hand use in daily life during hospitalization brings hand dysfunction to mind in inpatients. The aim of this study is to compare the hand functions of hospitalized patients with Rheumatoid Arthritis (RA to outpatients in detail. Methods: Grip and pinch strengths of both hospitalized patients in rheumatology service and outpatients on the routine control day were measured. In addition, 9-Hole Peg Test was performed and the disability level was determined by the Turkish version of Michigan Hand Outcomes Questionnaire (MHOQ. Results: While grip strength and MHOQ scores were similar (p>0.05 in both groups, all three pinch strengths (lateral, bipod, tripod and 9HPT scores were lower (p<0.05 in hospitalized patients. Conclusion: Consequently, besides disease activity, hospitalization process also impairs fine hand functions in rheumatological patients. Evaluation of fine hand functions and appropriate rehabilitative interventions may prevent further disability in hospitalized patients. J Clin Exp Invest 2015; 6 (3: 228-232
Full Text Available We investigate the relation between grip force and grip stiffness for the human hand with and without voluntary cocontraction. Apart from gaining biomechanical insight, this issue is particularly relevant for variable-stiffness robotic systems, which can independently control the two parameters, but for which no clear methods exist to design or efficiently exploit them. Subjects were asked in one task to produce different levels of force, and stiffness was measured. As expected, this task reveals a linear coupling between force and stiffness. In a second task, subjects were then asked to additionally decouple stiffness from force at these force levels by using cocontraction. We measured the electromyogram from relevant groups of muscles and analyzed the possibility to predict stiffness and force. Optical tracking was used for avoiding wrist movements. We found that subjects were able to decouple grip stiffness from force when using cocontraction on average by about 20% of the maximum measured stiffness over all force levels, while this ability increased with the applied force. This result contradicts the force–stiffness behavior of most variable-stiffness actuators. Moreover, we found the thumb to be on average twice as stiff as the index finger and discovered that intrinsic hand muscles predominate our prediction of stiffness, but not of force. EMG activity and grip force allowed to explain 72 ± 12% of the measured variance in stiffness by simple linear regression, while only 33 ± 18% variance in force. Conclusively the high signal-to-noise ratio and the high correlation to stiffness of these muscles allow for a robust and reliable regression of stiffness, which can be used to continuously teleoperate compliance of modern robotic hands.
Höppner, Hannes; Große-Dunker, Maximilian; Stillfried, Georg; Bayer, Justin; van der Smagt, Patrick
We investigate the relation between grip force and grip stiffness for the human hand with and without voluntary cocontraction. Apart from gaining biomechanical insight, this issue is particularly relevant for variable-stiffness robotic systems, which can independently control the two parameters, but for which no clear methods exist to design or efficiently exploit them. Subjects were asked in one task to produce different levels of force, and stiffness was measured. As expected, this task reveals a linear coupling between force and stiffness. In a second task, subjects were then asked to additionally decouple stiffness from force at these force levels by using cocontraction. We measured the electromyogram from relevant groups of muscles and analyzed the possibility to predict stiffness and force. Optical tracking was used for avoiding wrist movements. We found that subjects were able to decouple grip stiffness from force when using cocontraction on average by about 20% of the maximum measured stiffness over all force levels, while this ability increased with the applied force. This result contradicts the force–stiffness behavior of most variable-stiffness actuators. Moreover, we found the thumb to be on average twice as stiff as the index finger and discovered that intrinsic hand muscles predominate our prediction of stiffness, but not of force. EMG activity and grip force allowed to explain 72 ± 12% of the measured variance in stiffness by simple linear regression, while only 33 ± 18% variance in force. Conclusively the high signal-to-noise ratio and the high correlation to stiffness of these muscles allow for a robust and reliable regression of stiffness, which can be used to continuously teleoperate compliance of modern robotic hands. PMID:28588472
Joosten, Etienne; Detroyer, Elke; Milisen, Koen
Anaemia is a common problem in hospitalized older patients and is recognized as a risk factor for a significant number of adverse outcomes. Data of the effect of anaemia on functional status during hospitalization and mortality after discharge are limited. Aim of the study is to examine whether there is an association between anaemia, hand grip strength, gait speed and basic activities of daily living (ADL) during hospitalization and mortality 1 year after discharge in geriatric patients. In a prospective study, data on age, sex, body mass index, Mini-Mental State Examination (MMSE), main clinical diagnosis, number of comorbidities, hand grip strength, gait speed, ADL, haemoglobin, C-reactive protein and estimated Glomerular filtration ratio (eGFR) were recorded in 220 older patients, admitted to the acute geriatric ward of a university hospital. Anaemia was defined as a haemoglobin level anaemia (haemoglobin between 10 and 12 g/dL for women and 10 and 13 g/dL for men). Gait speed (in meters per second) was calculated after a 4.5 m walk and hand grip strength (in kilogram) was assessed with a hydraulic hand dynamometer. Functionality was assessed in the six basic activities of daily living. Information about the vital status was obtained 1 year after discharge with a telephone call. Analysis of covariance (ANCOVA) was used to examine the effect of the anaemia status on the walking speed, hand grip strength and premorbid ADL index and logistic regression analysis was used to examine whether anaemia could be identified as risk factors for mortality 12 months after discharge. Overall, 106 (48 %) patients had anaemia. Hand-grip strength, gait speed and ADL score were not significantly different between anaemic and non-anaemic hospitalized geriatric patients. After adjustment for age, sex, body mass index, eGFR, MMSE, number of comorbidities and main clinical diagnosis, the means for hand-grip strength were 17.3, 19.9 and 19.1 kg (p = 0.38); for gait speed 0
Full Text Available Su Hwan Lee, Soo Jung Kim, Yeji Han, Yon Ju Ryu, Jin Hwa Lee, Jung Hyun Chang Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Ewha Medical Research Institute, Ewha Womans University School of Medicine, Seoul, Korea Background: Muscle mass is known to be associated with mortality in elderly adults. Because hand grip strength (HGS is known as a simple assessment tool for muscular strength, many researchers have studied the association between HGS and disease. However, empirical evidence for the relationship between chronic obstructive pulmonary disease (COPD and HGS is still controversial. The aim of this study was to evaluate the association between COPD and HGS, using Korean population data. Methods: This was a population-based cross-sectional study. Data were obtained from the sixth Korean National Health and Nutrition Examination Survey, which was conducted from 2013 to 2015. To reduce the effects of HGS-related factors and potential confounding factors, propensity score matching was used to match subjects with and without COPD. Results: Among 14,930 subjects, 832 were enrolled in each group (non-COPD and COPD after propensity score matching. COPD subjects did not have lower HGS than non-COPD subjects (non-COPD vs COPD, male, 38.0±7.0 vs 38.9±7.0 kg, P=0.044, female, 23.8±4.6 vs 24.2±4.9 kg, P=0.342. Lung function was classified by Global Initiative for Chronic Obstructive Lung Disease stages and was not significantly associated with HGS. For male COPD subjects, there was a significant correlation between HGS and the EuroQol Five-Dimension Questionnaire (EQ5D utility score index, which is an indicator of quality of life that adjusts for age and body mass index (r=0.201, P<0.001. The correlation was absent for female subjects (r=0.098, P=0.170. Conclusion: COPD subjects did not have lower HGS than non-COPD subjects. HGS did not associate with lung function. However, the HGS of male COPD subjects was
Patrik Alexander Wikman
Full Text Available The neuroanatomical pathways interconnecting auditory and motor cortices play a key role in current models of human auditory cortex (AC. Evidently, auditory-motor interaction is important in speech and music production, but the significance of these cortical pathways in other auditory processing is not well known. We investigated the general effects of motor responding on AC activations to sounds during auditory and visual tasks. During all task blocks, subjects detected targets in the designated modality, reported the relative number of targets at the end of the block, and ignored the stimuli presented in the opposite modality. In each block, they were also instructed to respond to targets either using a precision grip, power grip, or to give no overt target responses. We found that motor responding strongly modulated AC activations. First, during both visual and auditory tasks, activations in widespread regions of AC decreased when subjects made precision and power grip responses to targets. Second, activations in AC were modulated by grip type during the auditory but not during the visual task. Further, the motor effects were distinct from the strong attention-related modulations in AC. These results are consistent with the idea that operations in AC are shaped by its connections with motor cortical regions.
Ozcan, Ayse; Tulum, Zeliha; Pinar, Lamia; Başkurt, Ferdi
This study was done to evaluate differences in pressure pain threshold, grip strength, manual dexterity and touch pressure threshold in the dominant and non-dominant hands of right- and left-handed subjects, and to compare findings within and between these groups. Thirty-nine right-handed and twenty-one left-handed subjects participated in the study. Pressure pain threshold was assessed using a dolorimeter, grip strength was assessed with a hand-grip dynamometer, manual dexterity was evaluated using the VALPAR Component Work Sample-4 system, and touch pressure threshold was determined using Semmes Weinstein monofilaments. Results for the dominant and non-dominant hands were compared within and between the groups. In the right-handed subjects, the dominant hand was significantly faster with the VALPAR Component Work Sample-4, showed significantly greater grip strength, and had a significantly higher pressure pain threshold than the non-dominant hand. The corresponding results for the two hands were similar in the left-handed subjects. The study revealed asymmetrical manual performance in grip strength, manual dexterity and pressure pain threshold in right-handed subjects, but no such asymmetries in left-handed subjects.
Vingerhoets, Guy; Clauwaert, Amanda
Clinical research suggests that imitating meaningless hand postures and pantomiming tool-related hand shapes rely on different neuroanatomical substrates. We investigated the BOLD responses to different tasks of hand posture generation in 14 right handed volunteers. Conjunction and contrast analyses were applied to select regions that were either common or sensitive to imitation and/or pantomime tasks. The selection included bilateral areas of medial and lateral extrastriate cortex, superior and inferior regions of the lateral and medial parietal lobe, primary motor and somatosensory cortex, and left dorsolateral prefrontal, and ventral and dorsal premotor cortices. Functional connectivity analysis revealed that during hand shape generation the BOLD-response of every region correlated significantly with every other area regardless of the hand posture task performed, although some regions were more involved in some hand postures tasks than others. Based on between-task differences in functional connectivity we predict that imitation of novel hand postures would suffer most from left superior parietal disruption and that pantomiming hand postures for tools would be impaired following left frontal damage, whereas both tasks would be sensitive to inferior parietal dysfunction. We also unveiled that posterior temporal cortex is committed to pantomiming tool grips, but that the involvement of this region to the execution of hand postures in general appears limited. We conclude that the generation of hand postures is subserved by a highly interconnected task-general neural network. Depending on task requirements some nodes/connections will be more engaged than others and these task-sensitive findings are in general agreement with recent lesion studies.
Reina, Nicolas; Cavaignac, Etienne; Trousdale, William H; Laffosse, Jean-Michel; Braga, José
It is widely hypothesized that mechanical loading, specifically repetitive low-intensity tasks, influences the inner structure of cancellous bone. As such, there is likely a relationship between handedness and bone morphology. The aim of this study is to determine patterns in trabecular bone between dominant and non-dominant hands in modern humans. Seventeen healthy patients between 22 and 32 years old were included in the study. Radial carpal bones (lunate, capitate, scaphoid, trapezium, trapezoid, 1st, 2nd and 3rd metacarpals) were analyzed with high-resolution micro-computed tomography. Additionally, crush and pinch grip were recorded. Factorial analysis indicated that bone volume ratio, trabeculae number (Tb.N), bone surface to volume ratio (BS.BV), body weight, stature and crush grip were all positively correlated with principal components 1 and 2 explaining 78.7% of the variance. Volumetric and trabecular endostructural parameters (BV/TV, BS/BV or Tb.Th, Tb.N) explain the observed inter-individual variability better than anthropometric or clinical parameters. Factors analysis regressions showed correlations between these parameters and the dominant side for crush strength for the lunate (r(2) = 0.640, P modern human wrist. © 2017 Anatomical Society.
Ruth E Propper
Full Text Available Unilateral hand clenching increases neuronal activity in the frontal lobe of the contralateral hemisphere. Such hand clenching is also associated with increased experiencing of a given hemisphere's "mode of processing." Together, these findings suggest that unilateral hand clenching can be used to test hypotheses concerning the specializations of the cerebral hemispheres during memory encoding and retrieval. We investigated this possibility by testing effects of unilateral hand clenching on episodic memory. The hemispheric Encoding/Retrieval Asymmetry (HERA model proposes left prefrontal regions are associated with encoding, and right prefrontal regions with retrieval, of episodic memories. It was hypothesized that right hand clenching (left hemisphere activation pre-encoding, and left hand clenching (right hemisphere activation pre-recall, would result in superior memory. Results supported the HERA model. Also supported was that simple unilateral hand clenching can be used as a means by which the functional specializations of the cerebral hemispheres can be investigated in intact humans.
Tomporowski, Phillip D.; Albrecht, Chelesa; Pendleton, Daniel M.
Purpose: The purpose of this study was to determine if physical arousal produced by isometric hand-dynamometer contraction performed during word-list learning affects young adults' free recall or recognition memory. Method: Twenty-four young adults (12 female; M[subscript age] = 22 years) were presented with 4 20-item word lists. Moderate arousal…
This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution...Electroencephalographic ( EEG ) measures demonstrate that a mere 90 seconds of left hand clenching increases right hemisphere activity, and similar right
Moscatelli, Fiorenzo; Valenzano, Anna; Petito, Annamaria; Triggiani, Antonio Ivano; Ciliberti, Michela Anna Pia; Luongo, Livio; Carotenuto, Marco; Esposito, Maria; Messina, Antonietta; Monda, Vincenzo; Monda, Marcellino; Capranica, Laura; Messina, Giovanni; Cibelli, Giuseppe
In taekwondo competitions, fatigue has a large influence on performance. Recent studies have reported that the excitability in the primary hand motor cortex, investigated with transcranial magnetic stimulation (TMS), is enhanced at the end of a maximal exercise and that this improvement correlates with blood lactate. The aim of the present study was to investigate the relationship between blood lactate and cortical excitability in taekwondo athletes and non-athletes. The excitability of the primary motor cortex was measured before and after fatiguing hand-grip exercise by TMS. Capillary blood lactate was measured at rest (pre-test), at the end (0 min), and at 3 and 10 min after the exercise by using a "Lactate Pro" portable lactate analyzer. Significant differences in cortical excitability between the two groups were found after the exercise (p taekwondo athletes, lactate may delay the onset of fatigue not only by maintaining the excitability of muscle, but also by increasing the excitability of the primary motor cortex more than in non-athletes.
Amano, Tatsuro; Kai, Seiko; Nakajima, Michi; Ichinose-Kuwahara, Tomoko; Gerrett, Nicola; Kondo, Narihiko; Inoue, Yoshimitsu
What is the central question of this study? Non-thermal factors (e.g. muscle metaboreflex) contribute to the sweating response during exercise. Although it is well recognized that the sweating responses caused by core temperature elevation in prepubertal children and the elderly are attenuated compared with young adults, it is unknown whether non-thermal sweating is also attenuated in these populations. What is the main finding and its importance? The non-thermal sweating response during isometric hand-grip exercise and isolated muscle metaboreflex were attenuated in prepubertal children compared with young adults in a non-uniform manner over the body, but only during the muscle metaboreflex in the elderly. This may explain the maturation- and ageing-related decline of sweating during exercise. The purpose of the present study was to investigate sweating responses to isometric hand-grip (IH) exercise and muscle metaboreflex in prepubertal children and the elderly. In hot conditions (ambient temperature, 35°C; relative humidity, 45%), 13 healthy young adults, 10 prepubertal children and 10 elderly subjects (aged 20.4 ± 1.2, 11.4 ± 0.5 and 63.5 ± 3.1 years, respectively) repeated a three hand-grip exercise protocol that consisted of 1 min IH exercise at 15, 30 or 45% of maximal voluntary contraction (MVC) followed by 2 min postexercise forearm occlusion. Local sweat rates (SRs) on the forehead, chest, forearm, thigh and palm were continuously measured (ventilated capsule method). The forehead SR in prepubertal children during IH exercise at 45% MVC was significantly lower than that of young adults (0.26 ± 0.22 and 0.08 ± 0.15 mg cm(-2) min(-1) for young adults and children, respectively; P elderly at any exercise intensities. The SR on the chest (0.22 ± 0.22 and -0.01 ± 0.05 mg cm(-2) min(-1) for young adults and children, respectively), forearm (0.14 ± 0.12 and 0.03 ± 0.04 mg cm(-2) min(-1) ) and thigh (0.13 ± 0.10 and 0
Lin, Jia-Hua; McGorry, Raymond W; Maikala, Rammohan V
Repetitive use of hand-held power tools is associated with work-related upper extremity musculoskeletal disorders. Using a pneumatic nutrunner, 21 men completed twelve 360 repetitive fastener-driving sessions on three joints (hard, soft and control) at slow and fast pace, and two different work:rest patterns. Handgrip force and perceived exertions were collected throughout each session. For the control joint, the mean grip force exerted was 39.6% of maximum voluntary exertion (MVE) whereas during hard and soft joint sessions it was 48.9% MVE and 56.9% MVE, respectively. Throughout each session, the grip force decreased, more while operating soft and hard joints as compared with the control joint (regression slope: -0.022 and -0.023, compared with -0.007 N/drive, respectively), suggesting considerable upper extremity muscular effort by participants during torque buildup. Fast work pace resulted in higher average grip forces by participants but a greater decrease in the force as the session progressed. Providing rest breaks reduced perceived exertions. The findings gain additional knowledge for assembly task design to possibly reduce the hand/arm injury risks for the operator. Practitioner Summary: Powered hand tools are widely used in assembly and manufacturing industries. However, the nature of their repetitive use on human operator biomechanical and perceptual responses is not fully understood. This study examined work-related risk factors such as joint torque, pace and work:rest ratios on powered hand tool performance.
Nascimento, Dahan da Cunha; Tibana, Ramires Alsamir; Benik, Franklin M; Fontana, Keila Elizabeth; Neto, Frederico Ribeiro; de Santana, Frederico Santos; Santos-Neto, Leopoldo; Silva, Renato André Sousa; Silva, Alessandro Oliveira; Farias, Darlan Lopes; Balsamo, Sandor; Prestes, Jonato
Introduction Hypertension is the most prevalent modifiable risk factor with a high prevalence among older adults. Exercise is a nonpharmacological treatment shown to benefit all patients with hypertension. Objective This study examined the effects of a 14-week moderate intensity resistance training program (RT) on the maintenance of blood pressure and hand grip strength during an extended detraining period in elderly hypertensive women. Methods Twelve hypertensive sedentary elderly women completed 14 weeks of whole body RT at a moderate perceived exertion following a detraining period of 14 weeks. Results Following the training period, participants demonstrated an increase in absolute hand grip strength (P=0.001), relative hand grip strength (P=0.032) and a decrease of systolic (P=0.001), diastolic (P=0.008), and mean blood pressure (P=0.002) when compared to pre-exercise values. In addition, these effects were sustained after 14 weeks of detraining. Conclusion Resistance training may be a valuable method to improve muscular strength and blood pressure in elderly people with benefits being maintained up to 14 weeks following training cessation. PMID:24477221
Pastacaldi, P.; Bracciaferri, F.; Neri, G.; Porciani, M.; Zolesi, V.
Experiments executed on the upper limb are assuming increasing significance in the frame of the Human Physiology in space, for at least two reasons: -the upper limb is the principal means of locomotion for the subject living in aspace station -fatigue can have a significant effect the hand, for the ordinary work on board,and in particular for the extra-vehicular activities. The degradation of the performances affecting the muscular-skeletal apparatus can be easily recognized on the upper limb, by exerting specific scientific protocols, to be repeated through the permanence of the subject in weightlessness conditions. Also, the effectiveness of adequate counter-measures aimed to the reduction of calcium and muscular mass need to be verified, by means of specific assessments on the upper limb. Another aspect relevant to the effect of microgravity on the upper limb is associated with the alteration of the motor control programs due to the different gravity factor, affecting not only the bio-mechanics of the subject, but in general all his/her psycho- physical conditions, induced by the totally different environment. Specific protocols on the upper limb can facilitate the studies on learning mechanisms for the motor control. The results of such experiments can be transferred to the Earth, useful for treatment of subjects with local traumas or diseases of the Central Nervous System.In the frame of the mission of the Italian astronaut Roberto Vittori on board the International Space Station (ISS), the Italian Space Agency (ASI) has promoted the program "Marco Polo", with a number of experiments devoted to the study of the effect of microgravity on the human body. The experiment CHIRO ("Crew's Health: Investigation on Reduced Operability) is a part of the program. Its purpose is the determination of the influence of the altered gravity on the control of the grip force exerted by the hand or by a group of fingers and the adaptive behavior of this control through the
Jonathan Ache Dias
Full Text Available O objetivo deste estudo foi verificar se existe efeito da preensão manual máxima (o ato de realizar ou não a preensão sobre o controle do equilíbrio de judocas em postura restrita, além de verificar se existe correlação entre a força de preensão manual (FPM e o controle do equilíbrio. Foram avaliados sete judocas com um dinamômetro e uma plataforma estabilométrica sendo mensuradas, concomitantemente, a FPM e o centro de pressão (CP. Foi verificado que até 80% da variabilidade do CP pode ser atrelada a preensão manual indicando que a mesma gera perturbações no controle do equilíbrio. Entretanto, foram encontradas correlações (r = 0,348 até 0,816 entre a FPM e o deslocamento do CP. Com isso pode-se concluir que, apesar da preensão manual gerar perturbações no equilíbrio, seu comportamento parece estar relacionado com os movimentos do corpo realizados para manter o equilíbrio, indicando uma possível correlação entre esses fenômenos.The purpose of this study was to verify if there is an effect of maximum hand grip (the act of performing or not the hand grip on the balance control of judokas in a restrict posture, and also to verify if there is a correlation between the hand grip strength (HGS and the balance control. Seven judokas were evaluated with a dynamometer and a stabilometric force platform, being measured, at the same time, the HGS and the center of pressure (COP. It was found that up to 80% of the COP variability was related to the hand grip demonstrating that it generates perturbations to the balance control. However, It was found correlations (r = 0,348 to 0,816 between de HGS and de COP displacement. With that, it can be concluded that, despite the hand grip generating perturbation on the balance, its behavior appears to be related to the body movements performed to sustain balance, indicating a possible correlation between this phenomenons.
Some hand and power tools were described. Section One describes several tools and shop techniques that may be useful in the home or commercial shop. Section Two contains descriptions of tools that are particularly applicable to industrial work, and in Section Three a number of metal working tools are presented.
Hammer, Paula E C; Shiri, Rahman; Kryger, Ann I;
-analyses. RESULTS: Of the 19 studies included, 17 were cross-sectional, 1 was a prospective cohort, and 1 a case-control study. The meta-analyses of studies that controlled their estimates for at least age and gender showed the associations of pinch grip work with proximal interphalangeal joint [OR 1.56, 95...
何其佳; 赵京东; 刘源
假手的运动拟人性主要体现在抓取过程中手指各个关节间的协同性上。根据神经学原理，人手完成一个抓握动作需要几十个肌肉协同作用。人手是假手设计的范本，将这个原理推广到假手中，通过2个电机的协同输入，实现四指12个关节的协同输出。协同的具体参数通过人手抓握数据采集的降维处理计算得出。在拟人假手的设计中，首次提出通过集成在手掌内部的微型行星齿轮来合成2路输入，实现协同控制。经过ADAMS仿真，本假手能够完成多种日常抓握姿势。%The anthropomorphic movement of a prosthetic hand is mainly reflected on the synergy a‐mong various joints of the fingers during the grabbing process .According to the principle in neurology ,a gripping action requires manpower to complete dozens of muscle synergies .Manpower is the template for prosthetic hand design .This principle will be extended to the prosthetic hand .Collaborative output of twelve joints of the four fingers is achieved by collaborative input of two motors .Specific parameters of the synergy are calculated by collection of hand gripping data and dimension reduction .The anthropomorphic prosthetic hand design first proposes that the integrated inside the palm of the minor planet gear can be used to synthesize two inputs to achieve cooperative control .According to the simulation of ADAMS ,the prosthetic hand can complete a variety of daily grip positions .
This GRIPS (Geothermal Resources Impact Project Study) contains over 1700 references on a wide variety of subjects dealing directly or indirectly with geothermal development at the Geysers/Calistoga KGRA. (MHR)
Nascimento D da C
Full Text Available Dahan da Cunha Nascimento,1,5,8 Ramires Alsamir Tibana,1,8 Franklin M Benik,2 Keila Elizabeth Fontana,3 Frederico Ribeiro Neto,8 Frederico Santos de Santana,5,8 Leopoldo Santos-Neto,4 Renato André Sousa Silva,1,5,6 Alessandro Oliveira Silva,1,7 Darlan Lopes Farias,1,7 Sandor Balsamo,4,5,8 Jonato Prestes1 1Postgraduate Program in Physical Education, Catholic University of Brasilia, Brasilia, Brazil; 2Department of Kinesiology and Sports Studies Graduate Program, Eastern Illinois University, Charleston, IL, USA; 3Faculty of Physical Education, University of Brasilia, Brasilia, Brazil; 4Graduate Program in Medical Sciences of the University of Brasilia, School of Medicine and Rheumatology Service, University Hospital of Brasilia (HUB, Brasilia, Brazil; 5Department of Physical Education, University Center Euro American University Center, Brasilia, Brazil; 6Center of Excellence in Medicine of Exercise (CEMEx, Brasilia, Brazil; 7Center University of Brasilia (UNICEUB, Brasilia, Brazil; 8Strength Training and Health Research Group (GEPEEFS, Brasilia, Brazil Introduction: Hypertension is the most prevalent modifiable risk factor with a high prevalence among older adults. Exercise is a nonpharmacological treatment shown to benefit all patients with hypertension. Objective: This study examined the effects of a 14-week moderate intensity resistance training program (RT on the maintenance of blood pressure and hand grip strength during an extended detraining period in elderly hypertensive women. Methods: Twelve hypertensive sedentary elderly women completed 14 weeks of whole body RT at a moderate perceived exertion following a detraining period of 14 weeks. Results: Following the training period, participants demonstrated an increase in absolute hand grip strength (P=0.001, relative hand grip strength (P=0.032 and a decrease of systolic (P=0.001, diastolic (P=0.008, and mean blood pressure (P=0.002 when compared to pre-exercise values. In addition, these
Radwin, Robert G; Chourasia, Amrish O; Howery, Robert S; Fronczak, Frank J; Yen, Thomas Y; Subedi, Yashpal; Sesto, Mary E
A laboratory study investigated the relationship between power hand tool and task-related factors affecting threaded fastener torque accuracy and associated handle reaction force. We previously developed a biodynamic model to predict handle reaction forces. We hypothesized that torque accuracy was related to the same factors that affect operator capacity to react against impulsive tool forces, as predicted by the model. The independent variables included tool (pistol grip on a vertical surface, right angle on a horizontal surface), fastener torque rate (hard, soft), horizontal distance (30 cm and 60 cm), and vertical distance (80 cm, 110 cm, and 140 cm). Ten participants (five male and five female) fastened 12 similar bolts for each experimental condition. Average torque error (audited - target torque) was affected by fastener torque rate and operator position. Torque error decreased 33% for soft torque rates, whereas handle forces greatly increased (170%). Torque error also decreased for the far horizontal distance 7% to 14%, when vertical distance was in the middle or high, but handle force decreased slightly 3% to 5%. The evidence suggests that although both tool and task factors affect fastening accuracy, they each influence handle reaction forces differently. We conclude that these differences are attributed to different parameters each factor influences affecting the dynamics of threaded faster tool operation. Fastener torque rate affects the tool dynamics, whereas posture affects the spring-mass-damping biodynamic properties of the human operator. The prediction of handle reaction force using an operator biodynamic model may be useful for codifying complex and unobvious relationships between tool and task factors for minimizing torque error while controlling handle force.
Full Text Available We examined the effect of hand grip on object recognition by studying the modulation of the mu rhythm when participants made object decisions to objects and non-objects shown with congruent or incongruent hand-grip actions. Despite the grip responses being irrelevant to the task, mu rhythm activity on the scalp over motor and pre-motor cortex was sensitive to the congruency of the hand grip – in particular the event related desynchronization of the mu rhythm was more pronounced for familiar objects grasped with an appropriate grip than for objects given an inappropriate grasp. Also the power of mu activity correlated with RTs to congruently gripped objects. The results suggest that familiar motor responses evoked by the appropriateness of a hand grip facilitate recognition responses to objects.
Dato, Serena; Soerensen, Mette; Montesanto, Alberto; Lagani, Vincenzo; Passarino, Giuseppe; Christensen, Kaare; Christiansen, Lene
An efficient uncoupling process is generally considered to have a protective effect on the aging muscle by slowing down its age-related decay. Genetic polymorphisms in the Uncoupling Protein 3 (UCP3) gene, whose product is mainly expressed in skeletal muscle, were suggested to be associated with hand grip (HG) performances in elderly populations. Considering the population specificity of the quality of aging, we aimed to add further support to this evidence by analyzing the association between four SNPs in the UCP3 gene and relative haplotypes in two large cohorts of middle aged (N=708) and oldest old Danes (N=908). We found that the variability at rs1685354 and rs11235972 was associated with HG levels both at single and haplotypic level in both cohorts. Furthermore, taking advantage of large cohort and period survival data of the oldest cohort, we tested the association of each SNP with survival at 10years from the baseline visit. Interestingly, we found that allele A at rs11235972, associated in this cohort with lowest HG scores, influences also the survival patterns, with people carrying this allele showing higher mortality rates. On the whole, our work supports the role of UCP3 gene in functional status and survival at old age.
Hilbert, M; Shushakov, V; Maassen, N
Acidification has been reported to provide protective effects on force production in vitro. Thus, in this study, we tested if respiratory acid-base changes influence muscle function and excitability in vivo. Nine subjects performed strenuous, intermittent hand grip exercises (10 cycles of 15 s of work/45 s of rest) under respiratory acidosis by CO(2) rebreathing, alkalosis by hyperventilation, or control. The Pco(2), pH, K(+) concentration ([K(+)]), and Na(+) concentration were measured in venous and arterialized blood. Compound action potentials (M-wave) were elicited to examine the excitability of the sarcolemma. The surface electromyogram (EMG) was recorded to estimate the central drive to the muscle. The lowest venous pH during the exercise period was 7.24 ± 0.03 in controls, 7.31 ± 0.05 with alkalosis, and 7.17 ± 0.04 with acidosis (P acidosis than with alkalosis, and, after the second cycle, it was smaller with acidosis than with the control condition (P Respiratory alkalosis stabilized the M-wave area without influencing performance. Thus, we did not find a direct link between performance and alteration of excitability of the sarcolemma due to changes in pH in vivo.
Pastacaldi, P.; Orsini, P.; Bracciaferri, F.; Neri, G.; Porciani, M.; Liuni, L.; Zolesi, V.
Experiments executed on the upper limb are assuming increasing significance in the frame of the Human Physiology in space, for at least two reasons: the upper limb is the principal means of locomotion for the subject living in a space station; furthermore, fatigue can have a significant effect on the hand, for the ordinary work on board, and in particular for the extra-vehicular activities. The degradation of the performances affecting the muscular-skeletal apparatus can be easily recognized on the upper limb, by exerting specific scientific protocols, to be repeated through the permanence of the subject in weightlessness conditions. Another aspect relevant to the effect of microgravity on the upper limb is associated with the alteration of the motor control programs due to the different gravity factor, affecting not only the bio-mechanics of the subject, but in general all his/her psycho-physical conditions, induced by the totally different environment. Specific protocols on the upper limb can facilitate the studies on learning mechanisms for the motor control. The results of such experiments can be transferred to the Earth, useful for treatment of subjects with local traumas or diseases of the Central Nervous System.
Sudhir Vinayakrao. Deshmukh
Full Text Available Study evaluates and assesses the work done by vibrating equipments. It includes the assessment of influence of various independent variables associated with hand tools, operators, work & environmental factors on various dependent variables. Three tools selected for study include Rock drill (Dry type (Tool-1, Concrete breaker (Tool-2, Hand grinder (Tool-3. The impact of vibration exposure on health of operators is assessed by the help of survey. It is found that the human energy expenditure is more in the subjects having low grip strength whereas it is less in the subjects of more grip strength. The subjects having more grip strength show less change in touch sensation. The human energy expenditure of subjects of hand grinder is significantly less than the subjects of rock drill and concrete breaker. The presence of hand arm vibration Syndrome (HAVS in the subjects under heavy work, like rock drill and concrete breaker found very high.
Matthieu B Trudeau
Full Text Available When holding a tablet computer with two hands, the touch keyboard configuration imposes postural constraints on the user because of the need to simultaneously hold the device and type with the thumbs. Designers have provided users with several possible keyboard configurations (device orientation, keyboard layout and location. However, potential differences in performance, usability and postures among these configurations have not been explored. We hypothesize that (1 the narrower standard keyboard layout in the portrait orientation leads to lower self-reported discomfort and less reach than the landscape orientation; (2 a split keyboard layout results in better overall outcomes compared to the standard layout; and (3 the conventional bottom keyboard location leads to the best outcomes overall compared to other locations. A repeated measures laboratory experiment of 12 tablet owners measured typing speed, discomfort, task difficulty, and thumb/wrist joint postures using an active marker system during typing tasks for different combinations of device orientation (portrait and landscape, keyboard layout (standard and split, and keyboard location (bottom, middle, top. The narrower standard keyboard with the device in the portrait orientation was associated with less discomfort (least squares mean (and S.E. 2.9±0.6 than the landscape orientation (4.5±0.7. Additionally, the split keyboard decreased the amount of reaching required by the thumb in the landscape orientation as defined by a reduced range of motion and less MCP extension, which may have led to reduced discomfort (2.7±0.6 compared to the standard layout (4.5±0.7. However, typing speed was greater for the standard layout (127±5 char./min. compared to the split layout (113±4 char./min. regardless of device orientation and keyboard location. Usage guidelines and designers can incorporate these findings to optimize keyboard design parameters and form factors that promote user performance
Trudeau, Matthieu B; Catalano, Paul J; Jindrich, Devin L; Dennerlein, Jack T
When holding a tablet computer with two hands, the touch keyboard configuration imposes postural constraints on the user because of the need to simultaneously hold the device and type with the thumbs. Designers have provided users with several possible keyboard configurations (device orientation, keyboard layout and location). However, potential differences in performance, usability and postures among these configurations have not been explored. We hypothesize that (1) the narrower standard keyboard layout in the portrait orientation leads to lower self-reported discomfort and less reach than the landscape orientation; (2) a split keyboard layout results in better overall outcomes compared to the standard layout; and (3) the conventional bottom keyboard location leads to the best outcomes overall compared to other locations. A repeated measures laboratory experiment of 12 tablet owners measured typing speed, discomfort, task difficulty, and thumb/wrist joint postures using an active marker system during typing tasks for different combinations of device orientation (portrait and landscape), keyboard layout (standard and split), and keyboard location (bottom, middle, top). The narrower standard keyboard with the device in the portrait orientation was associated with less discomfort (least squares mean (and S.E.) 2.9±0.6) than the landscape orientation (4.5±0.7). Additionally, the split keyboard decreased the amount of reaching required by the thumb in the landscape orientation as defined by a reduced range of motion and less MCP extension, which may have led to reduced discomfort (2.7±0.6) compared to the standard layout (4.5±0.7). However, typing speed was greater for the standard layout (127±5 char./min.) compared to the split layout (113±4 char./min.) regardless of device orientation and keyboard location. Usage guidelines and designers can incorporate these findings to optimize keyboard design parameters and form factors that promote user performance and
Background There is a high prevalence of non-specific shoulder pain associated with upper limb functional limitations in older adults. The purpose of this study was to determine the minimal clinically important differences (MCID) of grip strength and pressure pain threshold (PPT) in the upper limb between older adults with or without non-specific shoulder pain. Methods A case-control study was carried out following the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) criteria. A sample of 132 shoulders (mean ± SD years) with (n = 66; 76.04 ± 7.58) and without (n = 66; 75.05 ± 6.26) non-specific pain were recruited. The grip strength and PPT of the anterior deltoid and extensor carpi radialis brevis (ECRB) muscles were assessed. Results There were statistically significant differences (mean ± SD; P-value) for anterior deltoid PPT (2.51 ± 0.69 vs 3.68 ± 0.65, kg/cm2; P PPT (2.20 ± 0.60 vs 3.35 ± 0.38 kg/cm2; P PPT, ECRB PPT and grip strength, respectively, to assess the upper limb of older adults with non-specific shoulder pain after treatment. In addition, univariate and multivariate (linear regression and regression trees) analyses may be used to consider age distribution, sex, pain intensity, grip strength and PPT in older adults including clinical and epidemiological studies with non-specific shoulder pain. PMID:28289561
Cesar Calvo Lobo
Full Text Available Background There is a high prevalence of non-specific shoulder pain associated with upper limb functional limitations in older adults. The purpose of this study was to determine the minimal clinically important differences (MCID of grip strength and pressure pain threshold (PPT in the upper limb between older adults with or without non-specific shoulder pain. Methods A case-control study was carried out following the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE criteria. A sample of 132 shoulders (mean ± SD years with (n = 66; 76.04 ± 7.58 and without (n = 66; 75.05 ± 6.26 non-specific pain were recruited. The grip strength and PPT of the anterior deltoid and extensor carpi radialis brevis (ECRB muscles were assessed. Results There were statistically significant differences (mean ± SD; P-value for anterior deltoid PPT (2.51 ± 0.69 vs 3.68 ± 0.65, kg/cm2; P < .001, ECRB PPT (2.20 ± 0.60 vs 3.35 ± 0.38 kg/cm2; P < .001 and grip strength (20.78 ± 10.94 vs 24.63 ± 9.38 kg; P = .032 between shoulders with and without non-specific pain, respectively. Discussion The MCID of 1.17 kg/cm2, 1.15 kg/cm2 and 3.84 kg were proposed for anterior deltoid PPT, ECRB PPT and grip strength, respectively, to assess the upper limb of older adults with non-specific shoulder pain after treatment. In addition, univariate and multivariate (linear regression and regression trees analyses may be used to consider age distribution, sex, pain intensity, grip strength and PPT in older adults including clinical and epidemiological studies with non-specific shoulder pain.
Full Text Available Background. The majority of hand functionality tests are based on qualitative assessment which largely depends on the experience of the therapist. Computer-assisted methods can provide more objective and accurate measurements of the grip force and other parameters related to grasping.Methods. We analysed the grip force control in 12 patients with muscular dystrophy using the tracking system developed. The system consists of a grip-measuring device with endobjects assessing the force applied in different grips. The device was used as input to a tracking task where the patient applied the grip force according to the visual feedback from the computer screen. Each patient performed two tasks which consisted of tracking a ramp and sinus target.Results. We analysed the maximal grip force as assessed in the ramp task and the tracking accuracy of the sinus task. The results are compared among five different grips (cylindrical, lateral, palmar, pinch and spherical grip, applied with dominant and non-dominant hand. The results show no significant difference in tracking accuracy between the dominant and non-dominant hand.Conclusions. The results obtained in tracking the ramp target showed that the method could be used for the assessment of the muscle fatigue, providing quantitative information on muscle capacity. The results of the sinus-tracking task showed that the method can evaluate the grip force control in different types of grips, providing information on hand dexterity, muscle activation patterns or tremor.
Full Text Available It is well known that Gilles Deleuze is the heir of a complex vitalistic tradition, beginning with Henri Bergson’s Creative Evolution and spanning through an important part of 20th century French philosophy. According to this line of thought, philosophy has to sharpen its vision in order to grasp the irreducible nature of the living. On one hand Deleuze seems to explicitly follow these intuitions, on the other though he strives to find a viable ontological framework for an actual philosophy of life, reaffirming the Nietzschean notion of being as becoming, the Bergsonian virtual coexistence of memory and Scotist univocity of the being. Through such operation, Deleuze actually seems to distance himself from a simply vitalistic approach, and to build instead an original metaphysics that understands life as a powerful inorganic force crossing all levels of reality. The organic, thus, is what traps and diverts (détourne this impersonal and germinal life. Aim of the presentation is to clarify the originality of Deleuze’s vitalistic ontology and point to its ambiguities and debts towards other philosophical traditions. Even if Deleuze apparently overturns his vitalistic roots, it is nevertheless undeniable that the vital domain will engage him throughout all of his work.
Hank, K; Jürges, H; Schupp, J; Wagner, G G
This paper shows that the measurement of hand grip strength provides a non-invasive and reliable objective health indicator for social science research and is easy to collect in general population surveys. Grip strength is not only a useful complement of self-reported indicators of health, but it also exhibits a considerable predictive power with regard to a number of further relevant variables for social gerontological research, such as mortality risks. New data from the 2004 Survey of Health, Ageing and Retirement in Europe (SHARE) and the 2006 wave of the German Socio-Economic Panel Study (SOEP) allow insightful methodological and very first substantive cross-sectional analyses of grip strength in Germany. The focus of the present study is on the analysis of individuals aged 50 or older. The experience of both surveys when measuring grip strength is consistently positive, particularly with regard to the respondents' feedback. Major determinants of isometric grip strength are - beyond the individual's gender - age, body size and weight. A multivariate analysis also provides evidence for a clear positive association between various health indicators and grip strength.
The effectiveness of low-level laser therapy on pain, self-reported hand function, and grip strength compared to placebo or "sham" treatment for adults with carpal tunnel syndrome: A systematic review.
Burger, Marlette; Kriel, Réna; Damon, Andrea; Abel, Amy; Bansda, Anisha; Wakens, Marinique; Ernstzen, Dawn
Carpal tunnel syndrome (CTS) is one of the most common peripheral neuropathies in the upper extremity. The aim of this review was to systematically and critically appraise the available literature for the effectiveness of Low-Level Laser Therapy (LLLT) on pain, self-reported hand function, and grip strength compared to placebo treatment in adults with CTS. Seven databases were searched from 2000 to March 2015 namely: Cinahl, Cochrane Library, EBSCOhost, PEDro, PubMed, Science Direct, and Scopus. Key search terms were: CTS, LLLT, and physiotherapy. Specific inclusion and exclusion criteria were applied. The methodological quality was appraised with the PEDro scale. Data were extracted and captured on an Excel spreadsheet. The nine included randomized control trials (RCTs) had an average score of 8.2/11 according to the PEDro scale. The heterogeneity of the LLLT regimes used made statistical pooling inappropriate for this review and results were described narratively. No strong evidence exists concerning the effects of LLLT on CTS in adults. Studies that used 780-860 nm Lasers and energy dosages of 9-11 J/cm(2) or 10.8 J reported a more favorable outcome for pain, symptom severity, and functional ability as well as grip strength at the end of treatment and short-term follow up.
Hewson, David J; Li, Ke; Frerejean, Alexis; Hogrel, Jean-Yves; Duchene, Jacques
Grip force measurement is routinely used to identify pathologies, evaluate muscular function, and as part of rehabilitation. Grip force has also been shown to be a good indicator of the capacity of elderly to live independently owing to its strong relationship with clinical tests such as the Index of Activities of Daily Living. An autonomous, communicant grip-force measurement device is presented in this paper in order to perform grip-force evaluation at home. The Domo-Grip system consists of the Grip-Ball, the Grip-Box, and Grip-Soft. The Grip-Ball measures the pressure resulting from grip force, the Grip-Box serves as the communication hub, while Grip-Soft is an interactive software suite. The Domo-Grip system can be used as part of a home-based rehabilitation, and also for functional evaluation as part of an assessment of the capacity of elderly to live autonomously.
The aim of this study was to investigate the maximum acceptable contraction frequencies (i.e. work-rest cycles) for an isometric-intermittent handgrip task as a function of grip span, applied force and shoulder posture using psychophysical and physiological approaches. Twelve healthy males served as subjects. The three grip spans investigated were the optimal, 2 cm narrower than the optimal, and 2 cm wider than the optimal. The grip force levels studied were 15% and 30% of maximum voluntary grip force and the two shoulder postures were 25 degrees flexion and 30 degrees abduction. The psychophysical results indicate that subjects work faster with the narrower grip span at 15% of maximum voluntary grip force level in comparison to working with the optimal and the wider spans. However, when the task required 30% of maximum grip force level, the subjects worked faster with the optimal grip span. These findings were supported by the results of electromyography, heart rate, blood pressure and perceived discomfort. The study suggests that grip span of a tool is an important factor to be considered in predicting optimal work-rest cycles for hand grip tasks, and the optimum setting of grip span of the hand-tool depends on the required task force level. That is, the optimality is relative rather than absolute. In addition, it appears that weaker subjects can work at a higher rate than stronger ones at the same relative force level.
Di Domizio, Jennifer; Keir, Peter J
Direction of loading and performance of multiple tasks have been shown to elevate muscle activity in the upper extremity. The purpose of this study was to evaluate the effects of gripping on muscle activity and applied force during pushing and pulling tasks with three forearm postures. Twelve volunteers performed five hand-based tasks in supinated, neutral and pronated forearm postures with the elbow at 90 degrees and upper arm vertical. All tasks were performed with the right (dominant) hand and included hand grip alone, push and pull with and without hand grip. Surface EMG from eight upper extremity muscles, hand grip force, tri-axial push and pull forces and wrist angles were recorded during the 10 s trials. The addition of a pull force to hand grip elevated activity in all forearm muscles (all p push with grip tasks, forearm extensor muscle activity tended to increase when compared with grip only while flexor activity tended to decrease. Forearm extensor muscle activity was higher with the forearm pronated compared with neutral and supinated postures during most isolated grip tasks and push or pull with grip tasks (all p push and pull forces could act to assist in creating grip force, forearm muscle activity generally decreased. These results provide strategies for reducing forearm muscle loading in the workplace. STATEMENT OF RELEVANCE: Tools and tasks designed to take advantage of coupling grip with push or pull actions may be beneficial in reducing stress and injury in the muscles of the forearm. These factors should be considered in assessing the workplace in terms of acute and cumulative loading.
Vermillion, Billy C.; Lum, Peter S; Lee, Sang Wook
During object manipulation, grip force is coordinated with load force, which is primarily determined by object kinematics. Proximal arm kinematics may affect grip force control, as proximal segment motion could affect control of distal hand muscles via biomechanical and/or neural pathways. The aim of this study was to investigate the impact of proximal kinematics on grip force modulation during object manipulation. Fifteen subjects performed three vertical lifting tasks that involved distinct...
Hayden, Charles S.; Zechmann, Edward
At recent NOISE-CON and Acoustical Society of America meetings, noise rating labeling was discussed as a way of manufacturers providing full disclosure information for their noise emitting products. The first step is to gather sound power level data from these products. Sound power level data should be gathered in accordance with existing ANSI and/or ISO standards. Some standards, such as ANSI 12.15, may not define true operational noise emissions[r1] and thus may provide inaccurate information when that information is used to choose a hearing protection device or used to make a purchasing decision. A number of standards were systematically combined by NIOSH researchers to provide the most accurate information on sound power levels of powered hand tools used in the construction industry. This presentation will detail some of the challenges of existing ANSI 12.15 (and draft ANSI 12.41) to measure sound power levels of electric (and pneumatic) powered hand tools.
Nov 1, 2001 ... between strengths of dominant and non-dominant hands. Such discrepancy in ... methodological approaches in evaluation of grip strength, different .... Relations between stronger hand and hand preference. Stronger hand.
Shang, X.; Veldhuis, R.N.J.; Bazen, A.M.; Ganzevoort, W.P.T.
The Secure Grip project1 focuses on the development of a hand-grip pattern recognition system, as part of the smart gun. Its target customer is the police. To explore the authentication performance of this system, we collected data from a group of police officers, and made authentication simulations
Shang, X.; Veldhuis, Raymond N.J.; Bazen, A.M.; Ganzevoort, W.P.T.
The Secure Grip project1 focuses on the development of a hand-grip pattern recognition system, as part of the smart gun. Its target customer is the police. To explore the authentication performance of this system, we collected data from a group of police officers, and made authentication simulations
In our work the verification performance of a biometric recognition system based on grip patterns, as part of a smart gun for use by the police ocers, has been investigated. The biometric features are extracted from a two-dimensional pattern of the pressure, exerted on the grip of a gun by the hand
Tomás, Maria Teresa; Santa-Clara, Helena; Monteiro, Estela; Carolino, Elizabete; Freire, António; Barroso, Eduardo
Familial amiloidotic polyneuropathy (FAP) is an autossomical and dominant neurodegenerative disease related with systemic deposition of amyloid fibre mainly on peripheral nervous system. Clinically, is translated by an autonomous sensitive-motor polyneuropathy with beginning nearly always in foot, involving subsequently the hands. Until now, the unique available treatment for FAP disease is liver transplantation requiring medication that negatively affect muscle metabolism and force production mechanism. To our knowledge there are no quantitative characterizations of peak force in FAP patients or any comparison with healthy people. This knowledge will be extremely important to verify clinical and functional evolution of this disease and eventually prescribe an effective rehabilitation program. The purpose of this study was to analyse and compare levels of hand grip strength (peak force and endurance) in FAP patients with (FAPTx) or without (FAPNTx) a liver transplant with a group of healthy people (GC). The total sample of individuals where two hundred and six, assigned in 3 groups: 59 patients PAFNTx (23 males, 36 female; age 35 ± 8 years); 90 patients PAFTx (53 males, 37 females; age 34 ± 8 years) e 62 healthy persons (GC) (30 males, 32 females; age 33 ± 9 years). Grip strength was assessed by a portable grip dynamometer E-link (Biometrics Ltd, UK). All measurements were taken on standardized positions with standardized orders. The value noted to peak force was classified according to American College of Sports Medicine norms for grip strength. The 3 groups are differents (p < 0,05) for weigth, body mass index (BMI) and grip strength in both hands and endurance for left hand. Negative correlations between age and grip strength were found for PAFNTx and PAFTx but not for GC. According to our results FAP patients have lower values for grip strength in both hands than healthy subjects and consequently a worse classification in ACSM norms. Most patients present
Mat Jais, Ita Suzana; Chan, Kai Li; Loke, Mun Kitt Austin; Abdul Rahim, Saleem; Tay, Shian Chao
Cross-sectional study for clinical measurement. Most daily tasks require individuals to exert grip strength with torque, which can be challenging for elderly as their strength diminishes with age. We postulate that to assess the functional capacity of an individual, it is important to evaluate the functional grip strength instead of the maximal static grip strength. The objective of this cross-sectional study is to establish normative data for the functional grip strength of elderly aged 60 years and older in the Singapore population. In this study, 233 healthy subjects aged 60 years and older were recruited. Using a custom-made hand strength measurement device, the following measurements were recorded: grip strength at neutral position, grip strength with resistive pronation torque, and grip strength with resistive supination torque. Grip strengths measured for both genders decreased by 13% and 16% for males and females respectively, when pronation torque was exerted, and with supination torque, the strength decreased by 18% and 17% for males and females respectively. Normative data for the elderly population in Singapore had been established. The findings from this study can complement the existing ergonomic hand data in designing better assistive tools to improve the independent living of elderly. NA. Copyright © 2016 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.
Vermillion, Billy C; Lum, Peter S; Lee, Sang Wook
During object manipulation, grip force is coordinated with load force, which is primarily determined by object kinematics. Proximal arm kinematics may affect grip force control, as proximal segment motion could affect control of distal hand muscles via biomechanical and/or neural pathways. The aim of this study was to investigate the impact of proximal kinematics on grip force modulation during object manipulation. Fifteen subjects performed three vertical lifting tasks that involved distinct proximal kinematics (elbow/shoulder), but resulted in similar end-point (hand) trajectories. While temporal coordination of grip and load forces remained similar across the tasks, proximal kinematics significantly affected the grip force-to-load force ratio (P = 0.042), intrinsic finger muscle activation (P = 0.045), and flexor-extensor ratio (P muscles and the elbow joint cannot fully explain the observed changes, as task-related changes in intrinsic hand muscle activation were greater than in extrinsic hand muscles. Rather, between-task variation in grip force (highest during task 3) appears to contrast to that in shoulder joint velocity/acceleration (lowest during task 3). These results suggest that complex neural coupling between the distal and proximal upper extremity musculature may affect grip force control during movements, also indicated by task-related changes in intermuscular coherence of muscle pairs, including intrinsic finger muscles. Furthermore, examination of the fingertip force showed that the human motor system may attempt to reduce variability in task-relevant motor output (grip force-to-load force ratio), while allowing larger fluctuations in output less relevant to task goal (shear force-to-grip force ratio).
Cloutier, Aimee; Yang, James
In recent years, there has been a steep rise in the quality of prostheses for patients with upper limb amputations. Researchers have begun to identify methods of making prosthetic hands both functional and cosmetically appealing, in contrast to past designs. Many improvements have occurred because of novel design strategies, such as the use of underactuated mechanisms, which allow for more degrees of freedom (DOF) or help reduce the weight of the prosthesis. The increase in functionality is also due in large part to advancements in control strategies for prosthetic hands. One common control method, using electromyographic (EMG) signals generated by muscle contractions, has allowed for an increase in the DOF of hand designs and a larger number of available grip patterns with little added complexity for the wearer. Another recent improvement in prosthetic hand design instead employs electroneurographic (ENG) signals, requiring an interface directly with the peripheral nervous system (PNS) or the central nervous system (CNS). Despite the recent progress in design and control strategies, however, prosthetic hands are still far more limited than the actual human hand. This review outlines the recent progress in the development of electrode-based prosthetic hands, detailing advancements in the areas of design, sensory feedback, and control through EMG and ENG signals (with a particular focus on interfaces with the PNS). The potential benefits and limitations of both control strategies, in terms of signal classification, invasiveness, and sensory feedback, are discussed. Finally, a brief overview of interfaces with the CNS is provided, and potential future developments for prosthetic hand design are discussed.
Maurício Moreira Reis
Full Text Available Existe uma grande variedade de instrumentos utilizados para a avaliação da força de preensão manual. Porém, não existem estudos demonstrando a validade e a confiabilidade da maioria destes instrumentos. O objetivo deste estudo foi avaliar a validade concorrente e a confiabilidade intraexaminador do dinamômetro Saehan hidráulico comparado-o com o dinamômetro Jamar hidráulico. Cem indivíduos sadios (50 homens e 50 mulheres, entre 20 e 50 anos de idade, sem alterações cognitivas, deficiências físicas, disfunções neuromusculares e ortopédicas e história de lesões nos membros superiores, foram testados com os dinamômetros Jamar e Saehan. A validade concorrente entre o dinamômetro Jamar e o dinamômetro Saehan foi excelente para os testes de força de preensão realizados com as mãos direita (r=0,976 e esquerda (r=0,986. A confiabilidade intra-examinador foi excelente tanto para o dinamômetro Jamar (r=0,985 mãos direita e esquerda quanto para o dinamômetro Saehan (r=0,981 mão direita e r=0,985 mão esquerda. O dinamômetro Saehan é válido, confiável e comparável com o dinamômetro Jamar. Portanto, dados coletados com o dinamômetro Jamar são equivalentes aos dados coletados com o dinamômetro Saehan. Consequentemente, valores de força obtidos por testes com dinamômetro Saehan podem ser comparados com valores de referência de força de preensão que foram obtidos com o dinamômetro Jamar.There is a great variety of instruments available for evaluating hand grip strength. There is, however, a lack of studies showing the validity and reliability of most of these instruments. The purpose of this study was to examine the concurrent validity and test-retest reliability of the hydraulic Saehan dynamometer using the hydraulic Jamar dynamometer. One hundred healthy subjects (50 men and 50 women, between the ages of 20 and 50 years old, without cognitive impairment, physical disability, neuromuscular or orthopedic dysfunction
Full Text Available Biologically inspired robotic systems can find important applications in biomedical robotics, since studying and replicating human behaviour can provide new insights into motor recovery, functional substitution and human-robot interaction. The analysis of human hand motion is essential for collecting information about human hand movements useful for generalizing reaching and grasping actions on a robotic system. This paper focuses on the definition and extraction of quantitative indicators for describing optimal hand grasping postures and replicating them on an anthropomorphic robotic hand. A motion analysis has been carried out on six healthy human subjects performing a transverse volar grasp. The extracted indicators point to invariant grasping behaviours between the involved subjects, thus providing some constraints for identifying the optimal grasping configuration. Hence, an optimization algorithm based on the Nelder-Mead simplex method has been developed for determining the optimal grasp configuration of a robotic hand, grounded on the aforementioned constraints. It is characterized by a reduced computational cost. The grasp stability has been tested by introducing a quality index that satisfies the form-closure property. The grasping strategy has been validated by means of simulation tests and experimental trials on an arm-hand robotic system. The obtained results have shown the effectiveness of the extracted indicators to reduce the non-linear optimization problem complexity and lead to the synthesis of a grasping posture able to replicate the human behaviour while ensuring grasp stability. The experimental results have also highlighted the limitations of the adopted robotic platform (mainly due to the mechanical structure to achieve the optimal grasp configuration.
Easy Ergonomics: A Guide to Selecting Non-Powered Hand Tools Department of Industrial Relations Cal/OSHA Consultation Service Research ... puborder.asp http://www.cdc.gov/niosh Easy Ergonomics: A Guide to Selecting Non-Powered Hand Tools ...
Chang, Wen-Tung; Tseng, Ching-Huan; Wu, Long-Long
In this paper, an auxiliary methodology called the creative mechanism design is introduced into the innovation of gripping devices for prosthetic hands. This methodology is a systematic approach based on modification of existing devices for the generation of all possible topological structures of mechanisms and mechanical devices. An existing gripping device (Teh Lin ATG-5F prosthetic hand) constructed by a planar six-bar linkage with one degree of freedom is dealt with by using this methodology. Through the processes of generalization, number synthesis, specialization and particularization for the existing design, five new mechanisms are created in this study to apply to anthropomorphic prosthetic hands. The results show that the methodology for creative mechanism design is a powerful tool for creating new categories of mechanisms to avoid existing designs that have patent protection and can help designers in the conceptual phase. Also, this methodology is validated as a useful way to improve prosthetic hands for amputees.
Whelan, Lynsay; Flinn, Sharon; Wagner, Nathan
Based on recent advances in prosthetic technology available for individuals with partial hand loss or deficiency, research is needed to best ensure the acceptance of these devices. Additionally, this population is subjected to higher risks of overuse syndromes. With improved technological advances in prosthetic devices, clients can engage in more complex activities with less compensation. The purpose of this study was to describe the tasks identified as both difficult and important to individuals with partial hand loss. Recommendations will be provided regarding matching users' individualized goals with considerations in prosthetic design, functional training, programming, and adaptive equipment.
Goislard de Monsabert, Benjamin; Vigouroux, Laurent; Bendahan, David; Berton, Eric
Owing to limited quantitative data related to the loadings (forces and pressures) acting upon finger joints, several clinical observations regarding mechanical risk factors of hand osteoarthritis remain misunderstood. To improve the knowledge of this pathology, the present study used musculoskeletal modelling to quantify the forces and pressures acting upon hand joints during two grasping tasks. Kinematic and grip force data were recorded during both a pinch and a power grip tasks. Three-dimensional magnetic resonance imaging measurements were conducted to quantify joint contact areas. Using these datasets as input, a musculoskeletal model of the hand and wrist, including twenty-three degrees of freedom and forty-two muscles, has been developed to estimate joint forces and joint pressures. When compared with the power grip task, the pinch grip task resulted in two to eight times higher joint loadings whereas the grip forces exerted on each finger were twice lower. For both tasks, joint forces and pressures increased along a disto-proximal direction for each finger. The quantitative dataset provided by the present hand model clarified two clinical observations about osteoarthritis development which were not fully understood, i.e., the strong risk associated to pinch grip tasks and the high frequency of thumb-base osteoarthritis.
and experimental trials on an arm-hand robotic system. The obtained results have shown the effectiveness of the extracted indicators to reduce the non-linear optimization problem complexity and lead to the synthesis of a grasping posture able to replicate the human behaviour while ensuring grasp stability. The experimental results have also highlighted the limitations of the adopted robotic platform (mainly due to the mechanical structure to achieve the optimal grasp configuration.
Lin, Jia-Hua; Radwin, Robert; Nembhard, David
Applications of a new model for predicting power threaded-fastener-driving tool operator response and capacity to react against impulsive torque reaction forces are explored for use in tool selection and ergonomic workplace design. The model is based on a mechanical analog of the human operator, with parameters dependent on work location (horizontal and vertical distances); work orientation (horizontal and vertical); and tool shape (in-line, pistol grip, and right angle); and is stratified by gender. This model enables prediction of group means and variances of handle displacement and force for a given tool configuration. Response percentiles can be ascertained for specific tool operations. For example, a sample pistol grip nutrunner used on a horizontal surface at 30 cm in front of the ankles and 140 cm above the floor results in a predicted mean handle reaction displacement of 39.0 (SD=28.1) mm for males. Consequently 63%of the male users exceed a 30 mm handle displacement limit. When a right angle tool of similar torque output is used instead, the model predicted that only 4.6%of the male tool users exceed a 30 mm handle displacement. A method is described for interpolating individual subject model parameters at any given work location using linear combinations in relation to the range of modeled factors. Additional examples pertinent to ergonomic workstation design and tool selection are provided to demonstrate how the model can be used to aid tool selection and workstation design.
De Visser, H.; Herder, J.L.
This paper presents the design of a body-powered voluntary closing prosthetic hand. It is argued that the movement of the fingers before establishing a grip is much less relevant for good control of the object held than the distribution of forces once the object has been contacted. Based on this not
Richards, Daniel S; Georgilas, Ioannis; Dagnino, Giulio; Dogramadzi, Sanja
Robotic rehabilitation is a currently underutilised field with the potential to allow huge cost savings within healthcare. Existing rehabilitation exoskeletons oversimplify the importance of movement of the hand while undertaking everyday tasks. Within this study, an investigation was undertaken to establish the extent to which the degrees of freedom within the palm affect ability to undertake everyday tasks. Using a 5DT data glove, bend sensing resistors and restrictors of palm movement, 20 participants were recruited to complete tasks that required various hand shapes. Collected data was processed and palm arching trends were identified for each grasping task. It was found that the extent of utilizing arches in the palm varied with each exercise, but was extensively employed throughout. An exoskeleton was subsequently designed with consideration of the identified palm shapes. This design included a number of key features that accommodated for a variety of hand sizes, a novel thumb joint and a series of dorsally mounted servos. Initial exoskeleton testing was undertaken by having a participant complete the same exercises while wearing the exoskeleton. The angles formed by the user during this process were then compared to those recorded by 2 other participants who had completed the same tasks without exoskeleton. It was found that the exoskeleton was capable of forming the required arches for completing the tasks, with differences between participants attributed to individual ergonomic differences.
Sindbæk, Søren Michael
of communities and their life world. Transcending technology, cultural dispositions and social relations, the study of innovations invites an actor-networks approach, which considers the heterogeneous nature of human-material relations. The archaeological record is potentially a rich source of evidence...... on innovations. Mostly, however, the time-resolution of archaeological data is too coarse-grained to allow us to grasp this potential to the full. In the period c. AD 790-850 a distinctly new artistic motif, the Gripping Beast, emerged in Scandinavia. A series of narrowly dated contexts provide anchor points...
Wachter, N J; Mentzel, M; Hütz, R; Gülke, J
In the assessment of hand and upper limb function, detecting sincerity of effort (SOE) for grip strength is of major importance to identifying feigned loss of strength. Measuring maximal grip strength with a dynamometer is very common, often combined with calculating the coefficient of variation (CV), a measure of the variation over the three grip strength trials. Little data is available about the relevance of these measurements in patients with median nerve impairment due to the heterogeneity of patient groups. This study examined the reliability of grip strength tests as well as the CV to detect SOE in healthy subjects. The power distribution of the individual fingers and the thenar was taken into account. To assess reliability, the measurements were performed in subjects with a median nerve block to simulate a nerve injury. The ability of 21 healthy volunteers to exert maximal grip force and to deliberately exert half-maximal force to simulate reduced SOE in a power grip was examined using the Jamar(®) dynamometer. The experiment was performed in a combined setting with and without median nerve block of the same subject. The force at the fingertips of digits 2-5 and at the thenar eminence was measured with a sensor glove with integrated pressure receptors. For each measurement, three trials were recorded subsequently and the mean and CV were calculated. When exerting submaximal force, the subjects reached 50-62% of maximal force, regardless of the median nerve block. The sensor glove revealed a significant reduction of force when exerting submaximal force (P1 sensor) with (P<0.032) and without median nerve block (P<0.017). An increase in CV at submaximal force was found, although it was not significant. SOE can be detected with the CV at the little finger at using a 10% cut-off (sensitivity 0.84 and 0.92 without and with median nerve block, respectively). These findings suggest low reliability of the power grip measurement with the Jamar(®) dynamometer, as
Anson, J G; Hasegawa, Y; Kasai, T; Latash, M L; Yahagi, S
Our previous study revealed that, during tonic muscle contraction, remarkable functional differences among intrinsic and extrinsic muscles were observed during two different grip movements, i.e., precision and power grips. To verify whether this evidence is true even under the phasic muscle contraction, magnetic stimulation was delivered over the left scalp while a normal human subject performed phasic precision or power grip responses of the right-hand fingers in a simple reaction time (SRT) paradigm. Magnetic stimulation delivered during the latent period revealed different cortico-motoneuronal excitations between the two grip responses. In particular, the contributions of extensor carpi radialis (ECR) muscle were definitely different between the two grip responses, although motor-evoked potentials (MEPs) of first dorsal interosseous (FDI) prior to, and after EMG onset of movement initiation, were not different. These results were similar to previous results obtained during tonic muscle contraction. Thus, we have concluded that the task-dependent EMG discharge pattern in finger manipulation could not be modulated by muscle contraction modes.
Fain, Elizabeth; Weatherford, Cara
Cross-sectional research design. Clinical practice continues to use normative data for grip and pinch measurements that were established in 1985. There is no updated norms despite different hand usage patterns in today's society. Measuring and comparing grip and pinch strengths with normative data is a valid method to determine hand function. This research was implemented to compare the grip and pinch measurements obtained from healthy millennials to the established norms and to describe hand usage patterns for millennials. Grip and lateral pinch measurements were obtained from a sample of 237 healthy millennials (ages 20-34 years). Strength scores were statistically lower that older normative data in all millennial grip strengths, with the exception of the women in the age group of 30-34 years. Specifically, this statistically significant trend was observed in all male grip strengths, as well as in women in the age group of 20-24 years (bilateral grip) and 25-29 years (right grip). However, the lateral pinch data reflected was similar to the older norms with variances of 0.5-1 kg. Current data reflect statistically significant differences from the norms for all male grip measurements, as well as for women in the age group of 20-24 years (bilateral grip) and 25-29 years (right grip). No statistical significance was observed in the independent-sample t tests for the lateral pinch in men of all age groups. Statistical significance was noted for lateral pinch for female age groups for the left hand (20-24 years) and for bilateral lateral pinches (30-34 years). IV. Copyright Â© 2016 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.
Bergstra, S A; Murgia, A; Te Velde, A F; Caljouw, S R
Hand exercises are often part of the treatment of hand rheumatoid arthritis; however, it is still unclear whether and what type of exercises is effective in the treatment of this condition. Therefore, a systematic review into the effectiveness of hand exercises in the treatment of hand rheumatoid arthritis has been performed. Studies were identified in the literature databases by predefined search criteria. The eight included studies are peer-reviewed studies published between 2000 and 2014. Hand exercises differed between studies, but always included resistance and/or active range of motion exercises. Grip strength in various grip types (power grip, key pinch, precision pinch and tripod pinch) was found to improve by hand exercise therapy without having adverse effects on pain or disease activity. Adaptations in the range of motion in response to hand exercise therapy were less pronounced. There appears to be some transfer from the improvements on the body functioning level to the level of daily functioning, with the largest improvements found on grip ability. With regard to the intervention content, there was some evidence in favour of a longer therapy duration and a higher therapy intensity. No conclusions could be drawn on the effectiveness of the different types of exercises. Collectively, the studies indicate that hand exercises may have positive effects on strength and some aspects of daily functioning without aggravating disease activity or pain, although caution should be taken for subjects in the exacerbation period.
Wu, Lianjun; Jung de Andrade, Monica; Saharan, Lokesh Kumar; Rome, Richard Steven; Baughman, Ray H; Tadesse, Yonas
This paper focuses on design, fabrication and characterization of a biomimetic, compact, low-cost and lightweight 3D printed humanoid hand (TCP Hand) that is actuated by twisted and coiled polymeric (TCP) artificial muscles. The TCP muscles were recently introduced and provided unprecedented strain, mechanical work, and lifecycle (Haines et al 2014 Science 343 868-72). The five-fingered humanoid hand is under-actuated and has 16 degrees of freedom (DOF) in total (15 for fingers and 1 at the palm). In the under-actuated hand designs, a single actuator provides coupled motions at the phalanges of each finger. Two different designs are presented along with the essential elements consisting of actuators, springs, tendons and guide systems. Experiments were conducted to investigate the performance of the TCP muscles in response to the power input (power magnitude, type of wave form such as pulsed or square wave, and pulse duration) and the resulting actuation stroke and force generation. A kinematic model of the flexor tendons was developed to simulate the flexion motion and compare with experimental results. For fast finger movements, short high-power pulses were employed. Finally, we demonstrated the grasping of various objects using the humanoid TCP hand showing an array of functions similar to a natural hand.
... Navigation Bar Home Current Issue Past Issues Finding Relief from Allergy's Grip Past Issues / Summer 2006 Table ... action for patients who have had inadequate symptom relief with antihistamines and topical nasal steroids. Through injection ...
Kong, Yong-Ku; Lee, Kyung-Sun; Kim, Dae-Min; Jung, Myung-Chul
The objective of this study was to evaluate individual finger force and contribution to a gripping force, the difference between actual and expected finger forces and subjective discomfort rating at 10 different submaximal voluntary contraction (%MVC) levels (10-100% in 10 increments). Seventy-two participants randomly exerted gripping force with a multi-finger force measurement system. The individual finger force, gripping force and discomfort increased as %MVC levels increased. The middle and ring fingers exerted more force and contributed to a gripping force more than the index and little fingers due to their larger mass fractions of the digit flexor muscles. It was apparent at MVC; however, the index finger increased its contribution and exerted even more force than expected at more than 50% MVC. Subjective discomfort supported the results of the objective measures. This could explain the conflicting findings between index and ring fingers in previous finger contribution studies. STATEMENT OF RELEVANCE: Hand tool design is of special interest in ergonomics due to its association with musculoskeletal disorders in the hand. This study reveals a different contribution pattern of the fingers in submaximal voluntary contraction of gripping exertion.
Full Text Available Few studies have investigated the control of grip force when manipulating an object with an extremely small mass using a precision grip, although some related information has been provided by studies conducted in an unusual microgravity environment. Grip-load force coordination was examined while healthy adults (N = 17 held a moveable instrumented apparatus with its mass changed between 6 g and 200 g in 14 steps, with its grip surface set as either sandpaper or rayon. Additional measurements of grip-force-dependent finger-surface contact area and finger skin indentation, as well as a test of weight discrimination, were also performed. For each surface condition, the static grip force was modulated in parallel with load force while holding the object of a mass above 30 g. For objects with mass smaller than 30 g, on the other hand, the parallel relationship was changed, resulting in a progressive increase in grip-to-load force (GF/LF ratio. The rayon had a higher GF/LF force ratio across all mass levels. The proportion of safety margin in the static grip force and normalized moment-to-moment variability of the static grip force were also elevated towards the lower end of the object mass for both surfaces. These findings indicate that the strategy of grip force control for holding objects with an extremely small mass differs from that with a mass above 30 g. The data for the contact area, skin indentation, and weight discrimination suggest that a decreased level of cutaneous feedback signals from the finger pads could have played some role in a cost function in efficient grip force control with low-mass objects. The elevated grip force variability associated with signal-dependent and internal noises, and anticipated inertial force on the held object due to acceleration of the arm and hand, could also have contributed to the cost function.
George K. Hung
Full Text Available The objective of this article is to determine the effect of three different putting grips (conventional, cross-hand, and one-handed on variations in eye and head movements during the putting stroke. Seven volunteer novice players, ranging in age from 21 to 22 years, participated in the study. During each experimental session, the subject stood on a specially designed platform covered with artificial turf and putted golf balls towards a standard golf hole. The three different types of grips were tested at two distances: 3 and 9 ft. For each condition, 20 putts were attempted. For each putt, data were recorded over a 3-s interval at a sampling rate of 100 Hz. Eye movements were recorded using a helmet-mounted eye movement monitor. Head rotation about an imaginary axis through the top of the head and its center-of-rotation was measured by means of a potentiometer mounted on a fixed frame and coupled to the helmet. Putter-head motion was measured using a linear array of infrared phototransistors embedded in the platform. The standard deviation (STD, relative to the initial level was calculated for eye and head movements over the duration of the putt (i.e., from the beginning of the backstroke, through the forward stroke, to impact. The averaged STD for the attempted putts was calculated for each subject. Then, the averaged STDs and other data for the seven subjects were statistically compared across the three grip conditions. The STD of eye movements were greater (p < 0.1 for conventional than cross-hand (9 ft and one-handed (3 and 9 ft grips. Also, the STD of head movements were greater (p < 0.1; 3 ft for conventional than cross-hand and one-handed grips. Vestibulo-ocular responses associated with head rotations could be observed in many 9 ft and some 3 ft putts. The duration of the putt was significantly longer (p < 0.05; 3 and 9 ft for the one-handed than conventional and cross-hand grips. Finally, performance, or percentage putts made, was
Smit, G.; Plettenburg, D.H.; Van der Helm, F.C.
The goal of this study was to find an efficient method of energy transmission for application in an anthropomorphic underactuated body-powered (BP) prosthetic hand. A pulley-cable finger and a hydraulic cylinder finger were designed and tested to compare the pulley-cable transmission principle with
Dijk, van K.J.; Verhagen, R.; Noort, van den J.; Bour, L.J.; Veltink, P.H.; Heida, T.
Objective: The aim of the study is to test whether the PowerGlove (PG), an instrumented glove which consists of inertial (accelerometers and gyroscopes) and magnetic sensors, is a valid and reliable instrument to measure different degrees of hand motor impairments in patients with Parkinson’s diseas
Gubelmann, Cédric; Vollenweider, Peter; Marques-Vidal, Pedro
Background Mechanisms underlying the association between grip strength and cardiovascular mortality are poorly understood. We aimed to assess the association of grip strength with a panel of cardiovascular risk markers. Design The study was based on a cross-sectional analysis of 3468 adults aged 50-75 years (1891 women) from a population-based sample in Lausanne, Switzerland. Methods Grip strength was measured using a hydraulic hand dynamometer. Cardiovascular risk markers included anthropometry, blood pressure, lipids, glucose, adiposity, inflammatory and other metabolic markers. Results In both genders, grip strength was negatively associated with fat mass (Pearson correlation coefficient: women: -0.170, men: -0.198), systolic blood pressure (women: -0.096, men: -0.074), fasting glucose (women: -0.048, men: -0.071), log-transformed leptin (women: -0.074, men: -0.065), log-transformed high-sensitivity C-reactive protein (women: -0.101, men: -0.079) and log-transformed homocysteine (women: -0.109, men: -0.060). In men, grip strength was also positively associated with diastolic blood pressure (0.068), total (0.106) and low density lipoprotein-cholesterol (0.082), and negatively associated with interleukin-6 (-0.071); in women, grip strength was negatively associated with triglycerides (-0.064) and uric acid (-0.059). After multivariate adjustment, grip strength was negatively associated with waist circumference (change per 5 kg increase in grip strength: -0.82 cm in women and -0.77 cm in men), fat mass (-0.56% in women; -0.27% in men) and high-sensitivity C-reactive protein (-6.8% in women; -3.2% in men) in both genders, and with body mass index (0.22 kg/m(2)) and leptin (-2.7%) in men. Conclusion Grip strength shows only moderate associations with cardiovascular risk markers. The effect of muscle strength as measured by grip strength on cardiovascular disease does not seem to be mediated by cardiovascular risk markers.
Vanessa Luzia Barros de Andrade
Full Text Available Pinch grip is used in a large number of handling activities that require precision and control of an object. The position of the upper arm joints affects the fingers force production in order to handle the object. This study aimed to verify the influence of the wrist position in the production of maximum strength and in the control fingers grip pinch submaximum strength control. Participants were 21 right handed adults (10 male, 18-26 years old. They made two attempts of maximum force production and eight attempts of submaximal force production (four at 20% and four at 40% of maximum strength for pinch grip in three wrist positions: neutral, flexion and extension. The results showed that the production of maximum strength is higher in neutral position compared to wrist flexion and extension and higher for men compared to women. In addition, there was a positive correlation between the length of the hand and the production of maximum strength. The results also indicated that the wrist position did not interfere in the submaximum force control during this task. However, participants showed more difficulty controlling 20% than 40% of maximum strength. The present study showed evidence that the motor units used to produce grip pinch maximum strength cross the wrist joint but those used for the 20% and 40% of maximum strength are present only in the fingers and hand.
Slowik, Jonathan S; Requejo, Philip S; Mulroy, Sara J; Neptune, Richard R
The hand pattern (i.e., full-cycle hand path) used during manual wheelchair propulsion is frequently classified as one of four distinct hand pattern types: arc, single loop, double loop or semicircular. Current clinical guidelines recommend the use of the semicircular pattern, which is based on advantageous levels of broad biomechanical metrics implicitly related to the demand placed on the upper extremity (e.g., lower cadence). However, an understanding of the influence of hand pattern on specific measures of upper extremity muscle demand (e.g., muscle power and stress) is needed to help make such recommendations, but these quantities are difficult and impractical to measure experimentally. The purpose of this study was to use musculoskeletal modeling and forward dynamics simulations to investigate the influence of the hand pattern used on specific measures of upper extremity muscle demand. The simulation results suggest that the double loop and semicircular patterns produce the most favorable levels of overall muscle stress and total muscle power. The double loop pattern had the lowest full-cycle and recovery-phase upper extremity demand but required high levels of muscle power during the relatively short contact phase. The semicircular pattern had the second-lowest full-cycle levels of overall muscle stress and total muscle power, and demand was more evenly distributed between the contact and recovery phases. These results suggest that in order to decrease upper extremity demand, manual wheelchair users should consider using either the double loop or semicircular pattern when propelling their wheelchairs at a self-selected speed on level ground.
Gomes-Osman, Joyce; Tibbett, Jacqueline A.; Poe, Brandon P.; Field-Fote, Edelle C.
Many everyday tasks cannot be accomplished without adequate grip strength, and corticomotor drive to the spinal motoneurons is a key determinant of grip strength. In persons with tetraplegia, damage to spinal pathways limits transmission of signals from motor cortex to spinal motoneurons. Corticomotor priming, which increases descending drive, should increase corticospinal transmission through the remaining spinal pathways resulting in increased grip strength. Since the motor and somatosensory cortices share reciprocal connections, corticomotor priming may also have potential to influence somatosensory function. The purpose of this study was to assess changes in grip (precision, power) force and tactile sensation associated with two different corticomotor priming approaches and a conventional training approach and to determine whether baseline values can predict responsiveness to training. Participants with chronic (≥1 year) tetraplegia (n = 49) were randomized to one of two corticomotor priming approaches: functional task practice plus peripheral nerve somatosensory stimulation (FTP + PNSS) or PNSS alone, or to conventional exercise training (CET). To assess whether baseline corticospinal excitability (CSE) is predictive of responsiveness to training, in a subset of participants, we assessed pre-intervention CSE of the thenar muscles. Participants were trained 2 h daily, 5 days/week for 4 weeks. Thirty-seven participants completed the study. Following intervention, significant improvements in precision grip force were observed in both the stronger and weaker hand in the FTP + PNSS group (effect size: 0.51, p = 0.04 and 0.54, p = 0.03, respectively), and significant improvements in weak hand precision grip force were associated with both PNSS and CET (effect size: 0.54, p = 0.03 and 0.75, p = 0.02, respectively). No significant changes were observed in power grip force or somatosensory scores in any group. Across all groups
Gomes-Osman, Joyce; Tibbett, Jacqueline A; Poe, Brandon P; Field-Fote, Edelle C
Many everyday tasks cannot be accomplished without adequate grip strength, and corticomotor drive to the spinal motoneurons is a key determinant of grip strength. In persons with tetraplegia, damage to spinal pathways limits transmission of signals from motor cortex to spinal motoneurons. Corticomotor priming, which increases descending drive, should increase corticospinal transmission through the remaining spinal pathways resulting in increased grip strength. Since the motor and somatosensory cortices share reciprocal connections, corticomotor priming may also have potential to influence somatosensory function. The purpose of this study was to assess changes in grip (precision, power) force and tactile sensation associated with two different corticomotor priming approaches and a conventional training approach and to determine whether baseline values can predict responsiveness to training. Participants with chronic (≥1 year) tetraplegia (n = 49) were randomized to one of two corticomotor priming approaches: functional task practice plus peripheral nerve somatosensory stimulation (FTP + PNSS) or PNSS alone, or to conventional exercise training (CET). To assess whether baseline corticospinal excitability (CSE) is predictive of responsiveness to training, in a subset of participants, we assessed pre-intervention CSE of the thenar muscles. Participants were trained 2 h daily, 5 days/week for 4 weeks. Thirty-seven participants completed the study. Following intervention, significant improvements in precision grip force were observed in both the stronger and weaker hand in the FTP + PNSS group (effect size: 0.51, p = 0.04 and 0.54, p = 0.03, respectively), and significant improvements in weak hand precision grip force were associated with both PNSS and CET (effect size: 0.54, p = 0.03 and 0.75, p = 0.02, respectively). No significant changes were observed in power grip force or somatosensory scores in any group. Across all groups
Shechtman, Orit; Gutierrez, Zeida; Kokendofer, Emily
Controversy exists in the literature concerning the ability of the five-rung grip test to identify submaximal effort. The purpose of this study was to analyze four methods commonly used to evaluate the shape of the curve generated by maximal versus submaximal efforts. Thirty hand therapy patients performed the five-rung grip test maximally and submaximally with both their injured and uninjured hands. Grip strength scores were recorded at each of the five-rung positions. Next, four methods were used to analyze the data 1) visual analysis, 2) analysis of variance, 3) normalization, and 4) calculation of the standard deviation across the five strength scores. Analysis by all methods demonstrated that there were no differences between the injured hand exerting maximal effort and the uninjured hand exerting submaximal effort. In all four methods, the five-rung grip strength test was unable to distinguish between the injured hand exerting maximal effort and the uninjured hand exerting submaximal effort. The results suggest that the five-rung grip strength test should not be used to determine sincerity of effort in people with hand injuries, and that the shape of the curve generated by the five-rung grip strength test may not be related to level of effort but rather to the amount of force generated by the gripping hand.
Lindemann, Oliver; Abolafia, Juan M.; Girardi, Giovanna; Bekkering, Harold
To investigate the functional connection between numerical cognition and action planning, the authors required participants to perform different grasping responses depending on the parity status of Arabic digits. The results show that precision grip actions were initiated faster in response to small numbers, whereas power grips were initiated…
Full Text Available The handloom weaving industry is one of the ancient cottage industries in Bangladesh. Next to agriculture, it is the second largest sources of rural employment and income. The present study is an effort to investigate the present scenario of handloom weaving industries in Bangladesh. Also the analysis the properties and present trends of local woven fabric manufactured by Hand loom and Power loom. The study is based on secondary data.
Full Text Available The overwhelming majority of manual operations is even nowadays performed by using manual hand tools. These tools can be divided into 2 groups – hand tools designed for general use or a single-purpose hand tools for special operations. Tool described in this paper is used in assembling operation in the completion of electric motor. During the design of the existing tools the requirements for a functional part of the tool (lifespan, inability to damage the engine installation were fully considered, demands for ergonomic grip area, however, were not taken into account. Long-term use of incorrectly designed tool causes carpal tunnel syndrome, hand-arm vibration syndrome, diminished sensitivity or tingling in the fingers of workers. These difficulties can be reduced or entirely eliminated due to proper design of the grip of hand tool. Most authors focus on adjusting the grip for optimum ergonomics at individual types of grips (cylindrical, palmar, lateral, etc.. However, as already mentioned, there are tools for specific operations when the working area is limited by space or a specific type of load on the grip is needed. In some cases, it is often necessary to change the type of grip or combine different types of grips. This paper describes the design of an optimal grip of hand tool used for specific operation when assembling motors. Design of prototype mold and production of functional prototypes for ergonomics assessment directly in the workplace were realized. New design of handle should reduce the risk primarily of developing carpal tunnel in long-term use.
Mackay, Rebecca A.; Nathal, Michael V.
Specimens held without slippage, even at high temperatures. Improved gripping system designed to securely hold ends of specimen of composite material during creep or tensile test. Each grip includes pair of wedges having sharply corrugated gripping surfaces. Wedges held between two plates containing cavities sloped to accommodate wedges. Two such grips (one for each end) holds specimen in furnace connected to tensile test machine for creep measurements.
Saharan, Lokesh; de Andrade, Monica Jung; Saleem, Wahaj; Baughman, Ray H.; Tadesse, Yonas
Several works have been reported in powered hand orthosis in the last ten years for assistive or rehabilitative purposes. However, most of these approaches uses conventional actuators such as servo motors to power orthosis. In this work, we demonstrate the recently reported twisted and coiled polymeric (TCP) muscles to drive a compact, light, inexpensive and wearable upper extremity device, iGrab. A 3D printed orthotic hand module was designed, developed and tested for the performance. The device has six 2-ply muscles of diameter 1.35 mm with a length of 380 mm. We used a single 2-ply muscle for each finger and two 2-ply muscles for the thumb. Pulsed actuation of the muscles at 1.8 A current for 25 s with 7% duty cycle under natural cooling showed full flexion of the fingers within 2 s. Modeling and simulation were performed on the device using standard Euler–Lagrangian equations. Our artificial muscles powered hand orthosis demonstrated the capability of pinching and picking objects of different shapes, weights, and sizes.
Noé Gomes Borges Junior
Full Text Available The objective of this study was to compare maximum isometric grip strength (Fmaxbetween different sports and between the dominant (FmaxD and non-dominant (FmaxND hand. Twenty-nine male aikido (AI, jiujitsu (JJ, judo (JU and rowing (RO athletes and 21non-athletes (NA participated in the study. The hand strength test consisted of maintainingmaximum isometric grip strength for 10 seconds using a hand dynamometer. The position of the subjects was that suggested by the American Society of Hand Therapy. Factorial 2X5 ANOVA with Bonferroni correction, followed by a paired t test and Tukey test, was used for statistical analysis. The highest Fmax values were observed for the JJ group when using the dominant hand,followed by the JU, RO, AI and NA groups. Variation in Fmax could be attributed to handdominance (30.9%, sports modality (39.9% and the interaction between hand dominance andsport (21.3%. The present results demonstrated significant differences in Fmax between the JJ and AI groups and between the JJ and NA groups for both the dominant and non-dominant hand. Significant differences in Fmax between the dominant and non-dominant hand were only observed in the AI and NA groups. The results indicate that Fmax can be used for comparisonbetween different sports modalities, and to identify differences between the dominant and nondominanthand. Studies involving a larger number of subjects will permit the identification of differences between other modalities.
Doshi, R; Yeh, C; LeBlanc, M
Current prosthetic hands, although functional, have the potential of being improved significantly. We report here the design and development of a novel prosthetic hand that is lighter in weight, less expensive, and more functional than current hands. The new prosthesis features an endoskeleton embedded in self-skinning foam that provides a realistic look and feel and obviates the need for a separate cosmetic glove. The voluntary-closing mechanism offers variable grip strength. Placement of joints at three locations (metacarpophalangeal and proximal and distal interphalangeal) within each of four fingers affords realistic finger movement. High-strength synthetic cable attached to the distal phalanx of each finger is used to effect flexion. A multiposition passive thumb provides both precision and power grips. The new prosthesis can securely grasp objects with various shapes and sizes. Compared to current hands, weight has been reduced by approximately 50%, and cable excursion required for full finger flexion by more than 50%. The new endoskeletal prosthesis requires approximately 12-24% less force input to grasp a variety of everyday objects, largely due to its adaptive grip. Production cost estimates reveal the new prosthesis to be significantly less expensive than current prosthetic hands.
Luciane Fernanda Rodrigues Martinho Fernandes
Full Text Available O objetivo do estudo foi correlacionar a força de preensão palmar em diferentes posições de abertura, com variáveis antropométricas da mão. Participaram 73 voluntários de ambos os sexos (40 homens e 33 mulheres, com idade média de 23±4,61 anos. As medidas antropométricas largura da palma, comprimento do dedo indicador, espessura da palma, largura da mão, circunferência da palma e da mão foram realizadas bilateralmente. Para as medidas lineares, utilizou-se um paquímetro digital e, para as medidas de circunferência, a fita métrica. As medidas de força de preensão foram realizadas por meio de um dinamômetro hidráulico (UFTM Jamar®. Os valores antropométricos foram correlacionados com as medidas de força nas cinco posições de abertura. Os homens e as mulheres tiveram maior força na mão direita e, entre as posições, a maior força dos homens foi na de número 3 (45,5±15,53 kgf e das mulheres, na de posição 2 (25,5±6,28 kgf. Verificaram-se correlações significativas entre a força e os valores antropométricos nas medidas da largura da mão e circunferência da palma - que representam a maior medida transversal e o maior trofismo da mão, respectivamente, no grupo dos homens e a medida de comprimento do dedo, que representa a maior medida longitudinal no grupo das mulheres. Com isso, pode-se concluir que, para os homens, a maior força está relacionada à maior medida transversal e ao maior trofismo da mão e, para as mulheres, ao maior comprimento longitudinal da mão.The aim of this study was to correlate the grip strength of hand, in different opening positions, with hand anthropometric measures. The study included 73 volunteers (40 male and 33 female with mean age of 23±4.61 years old. Anthropometric measures, such as palm width, forefinger length, palm thickness, hand width, palm and hand circumferences, were performed bilaterally. For linear measures, a digital caliper rule was used as well as a tape
Full Text Available Anodal transcranial Direct Current Stimulation (tDCS has been shown to be an effective non-invasive brain stimulation method for improving cognitive and motor functioning in patients with neurological deficits. tDCS over motor cortex (M1, for instance, facilitates motor learning in stroke patients. However, the literature on anodal tDCS effects on motor learning in healthy participants is inconclusive, and the effects of tDCS on visuo-motor integration are not well understood. In the present study we examined whether tDCS over the contralateral motor cortex enhances learning of grip-force output in a visually guided feedback task in young and neurologically healthy volunteers. Twenty minutes of 1 mA anodal tDCS were applied over the primary motor cortex (M1 contralateral to the dominant (right hand, during the first half of a 40 min power-grip task. This task required the control of a visual signal by modulating the strength of the power-grip for six seconds per trial. Each participant completed a two-session sham-controlled crossover protocol. The stimulation conditions were counterbalanced across participants and the sessions were one week apart. Performance measures comprised time-on-target and target-deviation, and were calculated for the periods of stimulation (or sham and during the afterphase respectively. Statistical analyses revealed significant performance improvements over the stimulation and the afterphase, but this learning effect was not modulated by tDCS condition. This suggests that the form of visuomotor learning taking place in the present task was not sensitive to neurostimulation. These null effects, together with similar reports for other types of motor tasks, lead to the proposition that tDCS facilitation of motor learning might be restricted to cases or situations where the motor system is challenged, such as motor deficits, advanced age, or very high task demand.
Kim, Dae-Min; Kong, Yong-Ku
A total of 25 males participated to investigate the effects of the grip spans of pliers on the total grip force, individual finger forces and muscle activities in the maximum gripping task and wire-cutting tasks. In the maximum gripping task, results showed that the 50-mm grip span had significantly higher total grip strength than the other grip spans. In the cutting task, the 50-mm grip span also showed significantly higher grip strength than the 65-mm and 80-mm grip spans, whereas the muscle activities showed a higher value at 80-mm grip span. The ratios of cutting force to maximum grip strength were also investigated. Ratios of 30.3%, 31.3% and 41.3% were obtained by grip spans of 50-mm, 65-mm, and 80-mm, respectively. Thus, the 50-mm grip span for pliers might be recommended to provide maximum exertion in gripping tasks, as well as lower maximum-cutting force ratios in the cutting tasks.
Bird, R. Keith; Johnson, George W.
Pair of grips for tensile and compressive test specimens operate at temperatures up to 1,500 degrees F. Grips include wedges holding specimen inside furnace, where heated to uniform temperature. Hydraulic pistons drive wedges, causing them to exert clamping force. Hydraulic pistons and hydraulic fluid remain outside furnace, at room temperature. Cooling water flows through parts of grips to reduce heat transferred to external components. Advantages over older devices for gripping specimens in high-temperature tests; no need to drill holes in specimens, maintains constant gripping force on specimens, and heated to same temperature as that of specimen without risk of heating hydraulic fluid and acuator components.
Han, Wen-Peng; Huang, Yuan-Yuan; Yu, Miao; Zhang, Jun-Cheng; Yan, Xu; Yu, Gui-Feng; Zhang, Hong-Di; Yan, Shi-Ying; Long, Yun-Ze
A conventional electrospinning setup cannot work without a plug (electricity supply). In this article, we report a self-powered electrospinning setup based on a hand-operated Wimshurst generator. The new device has better applicability and portability than a typical conventional electrospinning setup because it is lightweight and can work without an external power supply. Experimental parameters of the apparatus such as the minimum number of handle turns to generate enough energy to spin, rotation speed of the handle and electrospinning distance were investigated. Different polymers such as polystyrene (PS), poly(vinylidene fluoride) (PVDF), polycaprolactone (PCL) and polylactic acid (PLA) were electrospun into ultrathin fibers successfully by this apparatus. The stability, reliability, and repeatability of the new apparatus demonstrate that it can be used as not only a demonstrator for an electrospinning process, but also a beneficial complement to conventional electrospinning especially where or when without a power supply, and may be used in wound healing and rapid hemostasis, etc.
Full Text Available With advances in technology and ageing societal concerns growing, personal care devices are gaining importance globally. One such area is lower-limb exoskeletons, used to assist persons to move around for normal daily living. Most of the commercially available assistive exoskeletons use rechargeable Li-ion batteries, which require frequent charging to meet the operational needs. Charging becomes a problem when a person relying on a mobility exoskeleton has to go outdoors for shopping or a leisure walk. Experimental data from on-going research to develop assistive mobility exoskeletons for elderly persons indicates that, the power required for exoskeletons is around 45–60 W which falls in the output range of hand-crank generators. So use of hand-crank generators as a charging source is discussed. In this work, we develop a mathematical model to investigate the potential of hand-crank devices in charging mobility exoskeletons and to give relation between input cranking speed and output charging power, and estimate the cranking time.
Lee, Sang Wook; Landers, Katlin A; Park, Hyung-Soon
Significant functional impairment of the hand is commonly observed among stroke survivors. In order to restore the functional use of the affected hand, we developed a biomimetic device that assists in generating functional movements of the hand. The device is actuated by exotendons that replicate the kinetic functional of the hand muscle-tendons, therefore it can reproduce the spatial finger joint coordination patterns of the functional manual tasks (e.g., power grip and pinch) with a reduced number of actuators. The system includes a thumb actuation mechanism, whose action is coordinated with finger exotendons to perform various manual tasks, thereby restoring the functional use of the hand. This paper presents the design of the device and the preliminary data of the functional movement generation by the system.
Kong, Yong-Ku; Seo, Min-Tae; Kang, Hyun-Sung
The present study evaluated the effect of grip span on finger forces and defined the best grip span for maximising total grip strength based on the finger forces and subjective discomfort in a static exertion. Five grip spans (45, 50, 55, 60 and 65 mm) of the opposing (A-type) handle shape were tested in this study to measure total grip strength and individual finger force among Korean population. A total of 30 males who participated in this study were asked to exert a maximum grip force with two repetitions, and to report the subjective discomfort experienced between exertions using the Borg's CR-10 scale. The highest grip strength was obtained at 45 mm and 50 mm grip spans. Results also showed that forces of all fingers, except for the middle finger force, significantly differed over the grip spans. The lowest subjective discomfort was observed in the 50 mm grip span. The results might be used as development guidelines for ergonomic opposing (A-type) hand tools for Korean population.
Joel M. Phillips M.S., OTRL
Full Text Available The purpose of this study was to create a norm reference of current grip and pinch strength norms for working-age Michigan adults. This normative study included a convenience sample of 179 volunteers who were employees at car plants in South East Michigan or hospital sites in West Michigan. Participants’ ages ranged from between 20 and 62 years of age with a mean age of 49.15 years. There were 78 females (44% and 101 males (56%. Subjects were classified by gender and in the age categories of ages 20 to 49 years and ages 50-62 years. Grip and pinch strength norms were collected following the American Society of Hand Therapy protocol. The norms from these working adults were calculated with descriptive statistics for males and females in two age classifications: ages 20 to 49 and ages 50 to 62 years. Standard Errors (SE are better than the 1985 norms for both males and females ages 20 to 49 years. SEs are higher than the ages 20 to 49 years’ norms for the ages 50 to 62 years age categories in both males and females. These norms offer a point of comparison for clinicians to use for clients in Michigan who are ages 20 to 62 years and who have a goal to improve their grip strength. Clients’ grip and pinch strength could be compared to their age level or gender norms using the comparison for one standard deviation above, below, or at the means.
Hamburg, E.; Vunder, V.; Johanson, U.; Kaasik, F.; Aabloo, A.
We report on a multifunctional four-finger gripper for soft robotics, suitable for performing delicate manipulation tasks. The gripping device is comprised of separately driven gripping and lifting mechanisms, both made from a separate single piece of smart material - ionic capacitive laminate (ICL) also known as artificial muscle. Compared to other similar devices the relatively high force output of the ICL material allows one to construct a device able to grab and lift objects exceeding multiple times its own weight. Due to flexible design of ICL grips, the device is able to adapt the complex shapes of different objects and allows grasping single or multiple objects simultaneously without damage. The performance of the gripper is evaluated in two different configurations: a) the ultimate grasping strength of the gripping hand; and b) the maximum lifting force of the lifting actuator. The ICL is composed of three main layers: a porous membrane consisting of non-ionic polymer poly(vinylidene fluoride-co-hexafluoropropene) (PVdF-HFP), ionic liquid 1-ethyl-3-methylimidazolium trifluoromethane-sulfonate (EMITFS), and a reinforcing layer of woven fiberglass cloth. Both sides of the membrane are coated with a carbonaceous electrode. The electrodes are additionally covered with thin gold layers, serving as current collectors. Device made of this material operates silently, requires low driving voltage (<3 V), and is suitable for performing tasks in open air environment.
Jin Hee Shim
Full Text Available BackgroundMeasuring grip and pinch strength is an important part of hand injury evaluation. Currently, there are no standardized values of normal grip and pinch strength among the Korean population, and lack of such data prevents objective evaluation of post-surgical recovery in strength. This study was designed to establish the normal values of grip and pinch strength among the healthy Korean population and to identify any dependent variables affecting grip and pinch strength.MethodsA cross-sectional study was carried out. The inclusion criterion was being a healthy Korean person without a previous history of hand trauma. The grip strength was measured using a Jamar dynamometer. Pulp and key pinch strength were measured with a hydraulic pinch gauge. Intra-individual and inter-individual variations in these variables were analyzed in a standardized statistical manner.ResultsThere were a total of 336 healthy participants between 13 and 77 years of age. As would be expected in any given population, the mean grip and pinch strength was greater in the right hand than the left. Male participants (137 showed mean strengths greater than female participants (199 when adjusted for age. Among the male participants, anthropometric variables correlated positively with grip strength, but no such correlations were identifiable in female participants in a statistically significant way.ConclusionsObjective measurements of hand strength are an important component of hand injury evaluation, and population-specific normative data are essential for clinical and research purposes. This study reports updated normative hand strengths of the South Korean population in the 21st century.
Zhang, Wei; Johnston, Jamie A; Ross, Mark A; Sanniec, Kyle; Gleason, Elizabeth A; Dueck, Amylou C; Santello, Marco
Carpal tunnel syndrome (CTS) impairs sensation of a subset of digits. Although the effects of CTS on manipulation performed with CTS-affected digits have been studied using precision grip tasks, the extent to which CTS affects multi-digit force coordination has only recently been studied. Whole-hand manipulation studies have shown that CTS patients retain the ability to modulate multi-digit forces to object mass, mass distribution, and texture. However, CTS results in sensorimotor deficits relative to healthy controls, including significantly larger grip force and lower ability to balance the torques generated by the digits. Here we investigated the effects of CTS on multi-digit force modulation to object weight when manipulating an object with a variable number of fingers. We hypothesized that CTS patients would be able to modulate digit forces to object weight. However, as different grip types involve the exclusive use of CTS-affected digits ('uniform' grips) or a combination of CTS-affected and non-affected digits ('mixed' grips), we addressed the question of whether 'mixed' grips would reduce or worsen CTS-induced force coordination deficits. The former scenario would be due to adding digits with intact tactile feedback, whereas the latter scenario might occur due to a potentially greater challenge for the central nervous system of integrating 'noisy' and intact tactile feedback. CTS patients learned multi-digit force modulation to object weight regardless of grip type. Although controls exerted the same total grip force across all grip types, patients exerted significantly larger grip force than controls but only for manipulations with four and five digits. Importantly, this effect was due to CTS patients' inability to change the finger force distribution when adding the ring and little fingers. These findings suggest that CTS primarily challenges sensorimotor integration processes for dexterous manipulation underlying the coordination of CTS-affected and non
Full Text Available Carpal tunnel syndrome (CTS impairs sensation of a subset of digits. Although the effects of CTS on manipulation performed with CTS-affected digits have been studied using precision grip tasks, the extent to which CTS affects multi-digit force coordination has only recently been studied. Whole-hand manipulation studies have shown that CTS patients retain the ability to modulate multi-digit forces to object mass, mass distribution, and texture. However, CTS results in sensorimotor deficits relative to healthy controls, including significantly larger grip force and lower ability to balance the torques generated by the digits. Here we investigated the effects of CTS on multi-digit force modulation to object weight when manipulating an object with a variable number of fingers. We hypothesized that CTS patients would be able to modulate digit forces to object weight. However, as different grip types involve the exclusive use of CTS-affected digits ('uniform' grips or a combination of CTS-affected and non-affected digits ('mixed' grips, we addressed the question of whether 'mixed' grips would reduce or worsen CTS-induced force coordination deficits. The former scenario would be due to adding digits with intact tactile feedback, whereas the latter scenario might occur due to a potentially greater challenge for the central nervous system of integrating 'noisy' and intact tactile feedback. CTS patients learned multi-digit force modulation to object weight regardless of grip type. Although controls exerted the same total grip force across all grip types, patients exerted significantly larger grip force than controls but only for manipulations with four and five digits. Importantly, this effect was due to CTS patients' inability to change the finger force distribution when adding the ring and little fingers. These findings suggest that CTS primarily challenges sensorimotor integration processes for dexterous manipulation underlying the coordination of CTS
Han, Wen-Peng; Huang, Yuan-Yuan; Yu, Miao; Zhang, Jun-Cheng; Yan, Xu; Yu, Gui-Feng; Zhang, Hong-Di; Yan, Shi-Ying; Long, Yun-Ze
A conventional electrospinning setup cannot work without a plug (electricity supply). In this article, we report a self-powered electrospinning setup based on a hand-operated Wimshurst generator. The new device has better applicability and portability than a typical conventional electrospinning setup because it is lightweight and can work without an external power supply. Experimental parameters of the apparatus such as the minimum number of handle turns to generate enough energy to spin, rotation speed of the handle and electrospinning distance were investigated. Different polymers such as polystyrene (PS), poly(vinylidene fluoride) (PVDF), polycaprolactone (PCL) and polylactic acid (PLA) were electrospun into ultrathin fibers successfully by this apparatus. The stability, reliability, and repeatability of the new apparatus demonstrate that it can be used as not only a demonstrator for an electrospinning process, but also a beneficial complement to conventional electrospinning especially where or when without a power supply, and may be used in wound healing and rapid hemostasis, etc.A conventional electrospinning setup cannot work without a plug (electricity supply). In this article, we report a self-powered electrospinning setup based on a hand-operated Wimshurst generator. The new device has better applicability and portability than a typical conventional electrospinning setup because it is lightweight and can work without an external power supply. Experimental parameters of the apparatus such as the minimum number of handle turns to generate enough energy to spin, rotation speed of the handle and electrospinning distance were investigated. Different polymers such as polystyrene (PS), poly(vinylidene fluoride) (PVDF), polycaprolactone (PCL) and polylactic acid (PLA) were electrospun into ultrathin fibers successfully by this apparatus. The stability, reliability, and repeatability of the new apparatus demonstrate that it can be used as not only a demonstrator
Bergman, K; Ornholmer, L; Zackrisson, K; Thyberg, M
Eight patients with a traumatic unilateral upper limb amputation, who used conventional myoelectric prostheses, were also fitted with a commercially available myoelectric prosthetic hand with an adaptive grip, in order to compare the functional benefit of the two types of prostheses. Comparisons were made regarding width of grip, force of grip, scores in a standardised grip function test and prosthesis preference. The conventional prosthesis showed significantly better results regarding these parameters. The adaptive hand does not appear to be fully developed for practical use in prosthetic rehabilitation.
Soma, Masayuki; Murata, Shin; Kai, Yoshihiro; Nakae, Hideyuki; Satou, Yousuke; Murata, Jun; Miyazaki, Junya
[Purpose] This study examined the relationship between toe grip strength and its associated factors by focusing on factors that were suggested to have a relationship with toe grip strength in previous studies, aiming to clarify the factors influencing the toe grip strength of healthy women. [Subjects and Methods] Twelve healthy young women were selected for this study. Their toe grip strength, angular changes in their ankle joint during toe grip, maximum voluntary contraction activities of the rectus femoris, biceps femoris, and tibialis anterior muscles, and the medial head of the gastrocnemius muscles were measured using electromyography. Their toe curl ability, foot-arch height ratio, and weight were also measured. [Results] Multiple regression analysis demonstrated that the predictors of toe grip strength in the resulting model were foot-arch height ratio and the percentage of integrated electromyography (%IEMG) of the tibialis anterior muscle, as the dependent variables. This reveals that women whose tibialis anterior muscle %IEMG values and foot-arch height ratio are high have greater %IEMG values have greater toe grip strength. [Conclusion] These findings suggest a significant relationship between foot-arch height ratio and toe grip strength, with a reciprocal interaction. These findings further indicate that the risk of falls by the elderly could be decreased if toe grip strength were enhanced, by increasing the height of a low foot-arch with the help of an inserted insole.
Günther, Christian M; Bürger, Alexander; Rickert, Markus; Crispin, Alexander; Schulz, Christoph U
The aim of this study was to update reference data of handgrip strength for healthy adults of both genders spanning a wide age range and to analyze possible factors of influence. Intraindividual and interindividual variations of grip strength and their relation to several anthropometric factors were analyzed in a standardized manner for 769 healthy adults (women, n = 403; men, n = 366) aged between 20 years and 95 years. Measurements were done in neutral position of arm, forearm, and wrist on setting II of a Baseline digital hydraulic dynamometer (NexGen Ergonomics Inc. Quebec, Canada). Mean strength was about 41% less in women (right 29 kg; left 27 kg) than in men (right 49 kg; left 47 kg) resulting in a ratio of left to right hand slightly above .95 in both genders. During the course of life, hand strength develops comparably in both genders peaking at 35 years of age and decreasing continuously further on. Anthropometric variables such as forearm circumference and length, hand size, or body mass showed a positive correlation with grip strength. Body mass index, type of work, and hand dominance showed only a partial positive correlation or no correlation with grip strength. Gender and age, followed by parameters representing body length and obesity, were observed to have the highest predictive value for handgrip strength and were therefore entered into the generation of prediction equations. We recommend side adjustment of measured values for intraindividual comparison and inclusion of information regarding anthropometric characteristics, as well as using gender- and age-adjusted reference values, whereas hand dominance can be neglected. The regression equations we generated might prove to be useful for clinicians or for those who use normative values within software to provide more accurate predictions of strength scores for specific applications.
Langlais, Sean M; Broker, Jeffrey P
Teaching and playing professionals offer multiple theories concerning the manner in which forces should be applied to the handle of the club during the golf swing. This study extends recent research concerning grip pressures and forces in golf, with the purpose of exploring the similarities and differences between force profiles for a 7-iron and driver swung by proficient golfers. A secondary purpose was to further analyze the way that golfers use grip forces to manipulate the club. Grip forces were measured on eight low handicap golfers (USGA indexes 0 to 7) swinging their own 7-irons and drivers. In total, lead-hand and trail-hand grip forces were isolated as well as anatomically specific forces within the hands. Force profile variability across multiple swings for each golfer and between golfers characterized consistencies and important differences. Correlations between 7-iron and driver force profiles characterized force 'signatures.' The data highlight large fluctuations in grip forces during the swing. Marked differences between participants were observed, involving force magnitudes and phasing. Dominant forces arose primarily from the lead hand, specifically the last three fingers. Force profiles were highly repeatable across swings for a golfer (standard deviations high (r2 = 0.86). Notably, within swing force variability was greatest during club acceleration, but dramatically decreased at impact.
Tajika, Tsuyoshi; Kobayashi, Tsutomu; Yamamoto, Atsushi; Shitara, Hitoshi; Ichinose, Tsuyoshi; Shimoyama, Daisuke; Okura, Chisa; Kanazawa, Saeko; Nagai, Ayako; Takagishi, Kenji
Grip and pinch strength are crucially important attributes and standard parameters related to the functional integrity of the hand. It seems significant to investigate normative data for grip and pinch strength of baseball players to evaluate their performance and condition. Nevertheless, few reports have explained the association between grip and pinch strength and anthropometric variables and types of pitch throwing for baseball pitchers. The aim of this study was to measure and evaluate clinical normative data for grip and tip, key, palmar pinch strength and to assess the relationship between these data and anthropometric variables and types of pitch throwing among Japanese high-school baseball pitchers. One hundred-thirty three healthy high school baseball pitchers were examined and had completed a self-administered questionnaire including items related to age, hand dominance, throwing ratio of type of pitch. A digital dynamometer was used to measure grip strength and a pinch gauge to measure tip, key and palmer pinch in both dominant and nondominant side. Body composition was measured by the multi frequency segmental body composition analyzer. Grip strength and tip and palmer pinch strength in dominant side were statistically greater than them in nondominant side (P types of pitches thrown and grip strength and tip, key, palmar pinch strength. Our result provides normative values and evidences for grip and pinch strengths in high school baseball pitchers.
Smit, Gerwin; Plettenburg, Dick H; van der Helm, Frans C T
The goal of this study was to find an efficient method of energy transmission for application in an anthropomorphic underactuated body-powered (BP) prosthetic hand. A pulley-cable finger and a hydraulic cylinder finger were designed and tested to compare the pulley-cable transmission principle with the hydraulic cylinder transmission principle. Both fingers had identical dimensions and a low mass. The only thing that differed between the fingers was the transmission principle. The input energy was measured for a number of tasks. The pulley-cable finger required more input energy than the hydraulic cylinder finger to perform the tasks. This was especially the case in tasks that required high pinch forces. The hydraulic cylinder transmission is therefore the more efficient transmission for application in BP prosthetic fingers.
Feix, Thomas; Kivell, Tracy L; Pouydebat, Emmanuelle; Dollar, Aaron M
Primates, and particularly humans, are characterized by superior manual dexterity compared with other mammals. However, drawing the biomechanical link between hand morphology/behaviour and functional capabilities in non-human primates and fossil taxa has been challenging. We present a kinematic model of thumb-index precision grip and manipulative movement based on bony hand morphology in a broad sample of extant primates and fossil hominins. The model reveals that both joint mobility and digit proportions (scaled to hand size) are critical for determining precision grip and manipulation potential, but that having either a long thumb or great joint mobility alone does not necessarily yield high precision manipulation. The results suggest even the oldest available fossil hominins may have shared comparable precision grip manipulation with modern humans. In particular, the predicted human-like precision manipulation of Australopithecus afarensis, approximately one million years before the first stone tools, supports controversial archaeological evidence of tool-use in this taxon.
Full Text Available The purpose of the present study was to investigate whether corticospinal projections from human supplementary motor area (SMA are functional during precise force control with the precision grip (thumb-index opposition. Since beta band corticomuscular coherence (CMC is well-accepted to reflect efferent corticospinal transmission, we analyzed the beta band CMC obtained with simultaneous recording of electroencephalographic (EEG and electromyographic (EMG signals. Subjects performed a bimanual precise visuomotor force tracking task by applying isometric low grip forces with their right hand precision grip on a custom device with strain gauges. Concurrently, they held the device with their left hand precision grip, producing similar grip forces but without any precision constraints, to relieve the right hand. Some subjects also participated in a unimanual control condition in which they performed the task with only the right hand precision grip while the device was held by a mechanical grip. We analyzed whole scalp topographies of beta band CMC between 64 EEG channels and 4 EMG intrinsic hand muscles, 2 for each hand. To compare the different topographies, we performed non-parametric statistical tests based on spatio-spectral clustering. For the right hand, we obtained significant beta band CMC over the contralateral M1 region as well as over the SMA region during static force contraction periods. For the left hand, however, beta band CMC was only found over the contralateral M1. By comparing unimanual and bimanual conditions for right hand muscles, no significant difference was found on beta band CMC over M1 and SMA. We conclude that the beta band CMC found over SMA for right hand muscles results from the precision constraints and not from the bimanual aspect of the task. The result of the present study strongly suggests that the corticospinal projections from human SMA become functional when high precision force control is required.
Schwarz, Peter; Jørgensen, Niklas; Nielsen, Barbara
-respiratory fitness with BMD at the spine and hip in men. RESULTS: The association between independent variables maximal aerobic capacity (VO(2max)), leg power and hand grip strength, and dependent variables BMD at the spine and total hip was explored in a series of linear regression models successively adjusted.......011) with BMD at total hip. CONCLUSIONS: We found that cardiorespiratory fitness was associated with BMD in men. Furthermore, hand grip strength and leg power were associated with increasing BMD at the lumbar spine and total hip in men, respectively. Further prospective studies are needed to further investigate...
Nishiyama, K; Taoda, K; Yamashita, H; Watanabe, S
This study examines the effect of the force with which a vibrating handle is gripped on the temporary threshold shift of vibratory sensation (TTSv) induced by hand-arm vibration. Six healthy subjects gripped a handle vibrating with a 1.3 octave-band vibration, with a central frequency of 200 Hz and an intensity of 39.2 m/s2. Exposure was for 1 min and 10 min, respectively. Gripping forces for the 1-min exposure were 5 N, 10 N, 40 N and 80 N, respectively, with 0 N push-pull force. Gripping forces for the 10-min exposure were the same as for the 1-min exposure but omitting 80 N. The vibratory sensation threshold at 125 Hz was measured before and after exposure of an exposed fingertip to vibration. The differences measured determine TTSv.t at time t. TTSv.t determines TTSv.0, that is, the temporary threshold shift of vibratory sensation immediately after exposure to vibration according to the estimate made on the basis of the preceding study. The same experimental conditions were repeated 3 times on different days in a soundproof and thermoregulated room. Our findings show that TTSv increases significantly with increasing gripping force. We also determined the quantitative relationships between TTSv.0 and gripping force as described by the equation TTSv.0 = exp(kf x F + Cf). where kt and Cf are constants and F is gripping force. This study revealed the importance of ergonomic design in reducing the force with which a vibrating handle is gripped to prevent an adverse effect of local vibration. The equation devised may help in the quantitative assessment of the effect of reduced gripping force.
Chen, Xin; Zheng, Yong-Ping; Guo, Jing-Yi; Shi, Jun
Our previous studies have demonstrated that the muscle thickness change detected by ultrasonography during contraction, namely sonomyography (SMG), can be used for functional assessment of skeletal muscles and has the potential for prosthetic control. In this study, we further investigated the feasibility of using one-dimensional SMG (1-D SMG) signal for controlling a powered prosthesis with one degree of freedom. The performance of SMG control in visual pursuit tracking of opening-closure patterns of the prosthesis was evaluated. Nine normal subjects including seven males and two females participated in the experiment. SMG signals were collected from the extensor carpi radialis muscle to control the opening position of the prosthetic hand. The subjects were instructed to perform the wrist extension movement to match the prosthesis response to the target sinusoid and square tracks under different movement rates as accurately as possible. The normalized root mean square (RMS) tracking error between the target track and the degree of the prosthetic hand's opening position, which was measured by an electronic goniometer, was calculated to evaluate the control performance. It was found that the mean RMS tracking errors of SMG control under different movement rates were 12.8 +/- 3.2% (mean +/- SD) and 14.8 +/- 4.6% for sinusoid and square tracks, respectively. Two-way analysis of variance (ANOVA) revealed significant differences in RMS tracking errors among the three movement rates (p = 2.0 x 10(-6)) and between the two target tracks (p = 0.007). The results suggest that SMG signal, based on further improvement, has potential to be an alternative method for prosthetic control.
Carey, Alan John
Astronaut hand fatigue during Extravehicular Activity (EVA) and EVA training is a critical risk in human space exploration. Improved glove designs over the past forty years have reduced hand fatigue, but limitations of the technology prevent major improvements to reduce hand fatigue. Therefore, a mechanism to assist astronauts by reducing hand fatigue was explored. Many organizations have already developed exoskeletons to assist astronauts, but all mechanisms developed required electrically powered actuators and control systems to enhance grip strength. However, astronauts already possess the strength required to actuate the glove; what is needed is a method to reduce fatigue without introducing electromechanical complexity. A passive mechanical system was developed as a proof-of-concept to test the feasibility of an unpowered exoskeleton to maintain static grip around an object. The semi- rigid nature of an inflated pressure glove provided an ideal substrate to mount a mechanism and associated components to allow an astronaut to release his/her grip inside the glove while maintaining attitude, as the mechanism will keep the glove closed around an object. Three prototypes were fabricated and tested to evaluate the architecture. The final two prototypes were tested on a real pressure suit glove at Final Frontier Design (FFD), and the third mechanism demonstrated attachment and basic operating principles. At University of California (UC) Davis, pressure glove analogs were fabricated from a baseball batting glove and polystyrene to simulate a real pressure glove without the risk of testing in a reduced pressure environment (i.e. a glove box). Testing of the third prototype showed a reduction in fatigue as measured by Maximum Voluntary Contraction (MVC) grip force over a 30 second period when the mechanism assisted gripping an object.
Full Text Available This paper focuses on how to provide mobility to people with motor impairments with the integration of robotics and wearable computing systems. The burden of learning to control powered mobility devices should not fall entirely on the people with disabilities. Instead, the system should be able to learn the user's movements. This requires learning the degrees of freedom of user movement, and mapping these degrees of freedom onto electric-powered wheelchair (EPW controls. Such mapping cannot be static because in some cases users will eventually improve with practice. Our goal in this paper is to present a hands-free interface (HFI that can be customized to the varying needs of EPW users with appropriate mapping between the users' degrees of freedom and EPW controls. EPW users with different impairment types must learn how to operate a wheelchair with their residual body motions. EPW interfaces are often customized to fit their needs. An HFI utilizes the signals generated by the user's voluntary shoulder and elbow movements and translates them into an EPW control scheme. We examine the correlation of kinematics that occur during moderately paced repetitive elbow and shoulder movements for a range of motion. The output of upper-limb movements (shoulder and elbows was tested on six participants, and compared with an output of a precision position tracking (PPT optical system for validation. We find strong correlations between the HFI signal counts and PPT optical system during different upper-limb movements (ranged from r = 0.86 to 0.94. We also tested the HFI performance in driving the EPW in a virtual reality environment on a spinal-cord-injured (SCI patient. The results showed that the HFI was able to adapt and translate the residual mobility of the SCI patient into efficient control commands within a week's training. The results are encouraging for the development of more efficient HFIs, especially for wheelchair users.
Chen, Bing; Lee, Yun-Ju; Aruin, Alexander S
We investigated motor control perspectives of coordinating maintenance of posture and application of grip force when holding an object and being perturbed. Ten subjects stood on the force platform holding an instrumented object in their dominant hand and were exposed to an external perturbation applied to their shoulders. Task demands were manipulated by positioning a slippery cap on top of the instrumented object. Grip force applied to the object, the object acceleration and the center of pressure (COP) were recorded and analyzed during the time intervals typical for the anticipatory (APA) and compensatory (CPA) components of postural control. Onsets of grip force were seen before the onsets of the COP displacement and initiation of movements of the handheld object during the APA phase of postural control, while the onsets of maximum grip force preceded the maximum COP displacement during the CPA phase. When the task demands increased by holding a handheld object with the slippery cap, subjects tended to generate grip force earlier and of a smaller magnitude; also, the COP displacement in the APA phase was smaller as compared to holding a handheld object only. The outcome provides a foundation for future studies of maintenance of vertical posture in people with impairments of balance and grip force control when holding an object and being perturbed.
Rowson, J; Yoxall, A
Society is ageing and sadly that ageing leads to a host of issues, not least a society in which the majority are likely to have some loss of strength and dexterity. This can lead to complications in undertaking everyday tasks such as using transport, bathing or even handling and opening food. Packaging has to provide a multitude of services; to protect and preserve the product, to provide information to the consumer and not least to allow access to the contents. This access to packaging--or 'openability'--has become a significant issue for designers and manufacturers with the change in demographics as described above. Understanding the choices consumers make in how they manipulate packaging can help designers produce packaging that is more able to meet the requirements of modern society. Studies previously undertaken by the authors showed that consumers did use different grips when opening packaging and that certain grips were theoretically more comfortable and stronger than others. This paper outlines a further study whereby consumers were asked to apply the most common grips to a specially designed torque measuring device. Details were taken about the consumers: age, gender, occupation, hand size, plus their preferred grip choice for packaging of this type. The study showed that typically women chose a grip that maximised their opportunity of opening the closure and that this grip choice was more limited than that available for men. This has implications for inclusive design of many everyday products.
Sanford, Joe; Young, Carolyn; Popa, Dan; Bugnariu, Nicoleta; Patterson, Rita
Research has expanded human-machine communication methods past direct programming and standard hand- held joystick control. Individual force sensors have been used as a simple means of providing environmental information to a robot and research has shown that more advanced sensitive skins can be viable input devices. These touch sensitive surfaces allow for additional modes of interaction between machines in open, undefined environments. These interactions include object detection for navigation and safety but can also be used for recognition of users command gestures by their machine partner. Key to successful implementation of these gestures is the understanding of varied strategies used for communication and interaction and the development of performance limits. Data of dominant hand grip forces was collected using a Tekscan Grip VersaTek Pressure Measurement System during opening of a door. Analysis of data from 10 male and female subjects is presented. The results of qualitative and quantitative analysis of these data show variability in hand configurations between users. Average data over the cohort is reported. These data will be used in future work to provide human metrology constraints and limits for use in simulation and design of new, physical human-robot interaction systems.
A força de preensão manual é boa preditora do desempenho funcional de idosos frágeis: um estudo correlacional múltiplo The hand-grip forecasts the functional performance of fragile elder subjects: a multiple-correlation study
Amandio A.R. Geraldes
Full Text Available A força de preensão manual (FPM associa-se com a funcionalidade de idosos, mas há dúvidas sobre o valor dessa relação em todas as situações. O estudo observou a correlação entre FPM de idosos residentes em instituições de cuidados permanentes (asilos e o desempenho funcional (DF em tarefas específicas e inespecíficas para as mãos. Participaram 12 homens (70±6 anos; 64±9 kg; 160±10 cm e sete mulheres (77±11 anos; 49±10 kg; 147±10 cm. A FPM foi medida com dinamômetro hidráulico. As tarefas motoras propostas foram: caminhar 10 m na velocidade máxima (C10, timed up & go test (TUGT, colocar e retirar chave de fechadura (TCCF e tirar e recolocar lâmpada em um bocal (TCLB. O teste de Wilcoxon revelou que os homens apresentaram melhores desempenhos que as mulheres em todos as medidas, exceto IMC, TCCF e TCLB (pHand-grip strength (HGS has been used to predict functional limitation in the elderly. However, this relationship in all situations is doubtful. The purpose of the study was to observe the association between HGS and functional performance (FP, in specific and not specific tasks among 19 long-term home elderly residents, 12 men (70±6 yrs; 64±9 kg; 160±10 cm and 7 women (77±11 yrs; 49±10 kg; 147±10 cm. HGS was measured by a hydraulic hand dynamometer. The FP was measured by the time to perform the following tasks: 1 habitual gait speed (HGS; 2 timed up & go test (TUGT; 3 opening a lock with a key (OLK; 4 to take off and put in a light bulb (TPB. The Wilcoxon test revealed that men were better than women in all measurements except for the IMC, OLK and TPL (p<0.05. The Spearman coefficients showed significant correlation between HGS and three FP tests: TPL (r=-.54; p=.018; TUGT (r=-.67; p=.002 and HGS (r=-.69; p=.001. The multiple correlation showed good correlation between the HGS and all FP tests (R=.66; R²=.44; p<.04. These results suggest that HGS may be a good predictor for FP, especially for fragile and
Validade preditiva de equações de referência para força de preensão manual em homens brasileiros de meia idade e idosos Predictive validity of reference equations to hand grip strength in Brazilian men of middle age and elderly
Alex de Andrade Fernandes
Full Text Available O objetivo deste estudo foi verificar a validade preditiva das equações de referência para predição da força de preensão manual (FPM em homens brasileiros de meia idade e idosos. Foram avaliados 60 homens com idade de 58,7±8,6 anos (50-84 anos, estatura 168,7±8,0 cm, massa corporal 67,9±13,0 kg e índice de massa corporal 23,7±4,0 kg/m², utilizando equipamento 'padrão-ouro' na avaliação da FPM e seguindo todas as recomendações metodológicas preconizadas pela American Society of Hand Therapists (ASHT. Os resultados do diagrama de Bland-Altman para mão dominante (MD apresentam um erro médio (viés de -8,4% (IC95% -51,6-34,7. Já o diagrama de Bland-Altman para mão não dominante (MND apresenta um erro médio (viés de 1,4% (IC95% -47,1-49,8. O cálculo de Cronbach's alpha para a MD foi de 0,69 e 0,59 para MND. O coeficiente de correlação intraclasse para MD foi 0,52 (IC95% 31-68 e de 0,42 (IC95% 20-60 para a MND. Concluímos que as equações para predição analisadas neste estudo, para uma população de homens brasileiros de meia idade e idosos, apresentou baixa validade preditiva, o que pode gerar erros de interpretação dos resultados.The objective of this study was to verify the predictive validity of reference equations for hand grip strength (HGS in middle-aged and elderly Brazilian men. We evaluated 60 men with age of 58.7±8.6 years, height 168.7±8.0 cm, body mass 67.9±13.0 kg, and body mass index 23.7±4.0 kg/m², utilizing the gold standard equipment for evaluation of HGS and following all methodological recommendations of the American Society of Hand Therapists (ASTH. The results of the Bland-Altman diagram for the dominant hand (DH had a mean error (bias of -8.4% (95%CI -51.6-34.7. The Bland-Altman diagram for the non-dominant hand (NDH had a mean error (bias of 1.4% (95%CI -47.1-49.8. The calculation of Cronbach's alpha was 0.69 for the DH and 0.59 for the NDH. The intraclass correlation coefficient was 0
Jain, Rahul; Sain, Manoj Kumar; Meena, Makkhan Lal; Dangayach, Govind Sharan; Bhardwaj, Awadhesh Kumar
In lower-middle-income countries, most of the work is performed manually using non-ergonomic hand tools which results in work-related health problems. Using hand tools designed in line with ergonomic principles may play an important role in reducing work-related health concerns significantly. Scientific databases (PubMed, EBSCOhost) and e-publishers were searched for articles from 1985 to 2015 using the following keywords: 'hand tool', 'ergonomics', 'usability' and 'design'. After applying selection criteria to 614 articles, 58 articles related to the physical design of hand tools were selected. Seventeen articles were related to hand tool improvement in the manufacturing sector. Musculoskeletal disorders were found to be the most frequently occurring work-related health problems. Most of the articles focused on product and qualitative variables for improvement in hand tools, while few articles considered human and task variables. Literature shows that hand tool improvement studies have been given less importance in low-income and lower-middle-income countries. However, some work of significance is reported in the agriculture sectors of these countries. Hence, it is concluded that ergonomic intervention in hand tools is much needed for those industries which employ traditional methods of working.
Delph, Michael A; Fischer, Sarah A; Gauthier, Phillip W; Luna, Carlos H Martinez; Clancy, Edward A; Fischer, Gregory S
Stroke affects 750,000 people annually, and 80% of stroke survivors are left with weakened limbs and hands. Repetitive hand movement is often used as a rehabilitation technique in order to regain hand movement and strength. In order to facilitate this rehabilitation, a robotic glove was designed to aid in the movement and coordination of gripping exercises. This glove utilizes a cable system to open and close a patients hand. The cables are actuated by servomotors, mounted in a backpack weighing 13.2 lbs including battery power sources. The glove can be controlled in terms of finger position and grip force through switch interface, software program, or surface myoelectric (sEMG) signal. The primary control modes of the system provide: active assistance, active resistance and a preprogrammed mode. This project developed a working prototype of the rehabilitative robotic glove which actuates the fingers over a full range of motion across one degree-of-freedom, and is capable of generating a maximum 15N grip force.
Gaertner, K. P.
A twin-grip control yoke was designed as an ergonomic case study that allows dual axis control inputs, both axes being rotational. Inputs are effected by rotating the grips. How the handles were designed with respect to their shape and size and how the angular range of the control yoke in both rotational axes was evaluated. The control yoke which requires two-hand operation was tested to determine its operating range. The intention of this investigation was to find out the optimal form of the control yoke and the maximum permissible range in both rotating axes. In these experiments controls had no spring resistance.
Elk, N. van; Faes, M.C.; Degens, H.; Kooloos, J.G.M.; Lint, J.A. de; Hopman, M.T.E.
STUDY DESIGN: Experimental repeated-measures study. OBJECTIVE: To investigate the effect of different extension forces applied to the palm of the hand on electromyographic (EMG) activity of the wrist extensor muscles during hand gripping. BACKGROUND: Lateral epicondylitis is usually caused by repeti
Kloosterman, Marieke G. M.; Buurke, Jaap H.; de Vries, Wiebe; Van der Woude, Lucas H. V.; Rietman, Johan S.
This study aims to compare hand-rim and power-assisted hand-rim propulsion on potential risk factors for shoulder overuse injuries: intensity and repetition of shoulder loading and force generation in the extremes of shoulder motion. Eleven experienced hand-rim wheelchair users propelled an instrume
Full Text Available Background: Patients with congenital and acquired hemiparesis incur long-term functional deficits, among which the loss of prehension that may impact their functional independence. Identifying, understanding and comparing the underlying mechanisms of prehension impairments represent an opportunity to better adapt neurorehabilitationObjective: The present review aims to provide a better understanding of precision grip deficits in congenital and acquired hemiparesis and to determine whether the severity and type of fine motor control impairments depend on whether or not the lesions are congenital or acquired in adulthood. Methods: Using combinations of the following key words: fingertip force, grip force, precision grip, cerebral palsy, stroke, pubmed and Scopus databases were used to search studies from 1984 to 2013. Results: Individuals with both congenital and acquired hemiparesis were able to some extent to use anticipatory motor control in precision grip tasks, even if this control was impaired in the paretic hand. In both congenital or acquired hemiparesis, the ability to plan efficient anticipatory motor control when the less-affected hand is used provides a possibility to remediate impairments in anticipatory motor control of the paretic hand. Conclusion: Surprisingly we observed very few differences between the results of studies in children with congenital hemiplegia and stroke patients. We suggest that the underlying specific strategies of neurorehabilitation developed for each one could benefit the other.
Bartoli, Eleonora; Maffongelli, Laura; Jacono, Marco; D'Ausilio, Alessandro
The term affordance defines a property of objects, which relates to the possible interactions that an agent can carry out on that object. In monkeys, canonical neurons encode both the visual and the motor properties of objects with high specificity. However, it is not clear if in humans exists a similarly fine-grained description of these visuomotor transformations. In particular, it has not yet been proven that the processing of visual features related to specific affordances induces both specific and early visuomotor transformations, given that complete specificity has been reported to emerge quite late (300-450ms). In this study, we applied an adaptation-stimulation paradigm to investigate early cortico-spinal facilitation and hand movements׳ synergies evoked by the observation of tools. We adapted, through passive observation of finger movements, neuronal populations coding either for precision or power grip actions. We then presented the picture of one tool affording one of the two grasps types and applied single-pulse Transcranial Magnetic Stimulation (TMS) to the hand primary motor cortex, 150ms after image onset. Cortico-spinal excitability of the Abductor Digiti Minimi and Abductor Pollicis Brevis showed a detailed pattern of modulations, matching tools׳ affordances. Similarly, TMS-induced hand movements showed a pattern of grip-specific whole hand synergies. These results offer a direct proof of the emergence of an early visuomotor transformation when tools are observed, that maintains the same amount of synergistic motor details as the actions we can perform on them.
Shamsoddini, Alireza; Hollisaz, Mohammad Taghi
Background Tennis elbow (TE) is a common musculotendinous degenerative disorder of the extensor origin at the lateral humeral epicondyle. Different modes of treatment are used for management of tennis elbow. Objectives This study investigated the effect of the taping technique (TT) on pain, grip strength and wrist extension force in treatment of tennis elbow. Patients and Methods Thirty patients (16 men /14 women with a mean age of 32.2 years) with tennis elbow of their dominant arm participated in this study. Outcome measures were assessment of pain at the lateral aspect of the elbow, grip strength and wrist extension force before and five to ten minutes after application of elbow tape on the affected and unaffected arms. A Visual Analog Scale was used to assess pain. A dynamometer and a hand-held dynamometer were used for evaluation of grip strength and wrist extension force, respectively. Results Among the variables, significant differences were found in wrist extension forces between effected and unaffected arms (P = 0.02). Changes in grip strength showed statically significant improvements in the affected arm compared to the unaffected arm (P = 0.03). Also, in assessment of pain at the lateral epicondyle, the mean change between affected and unaffected arms was significant, with P = 0.001. Conclusions The taping technique, as applied in this study demonstrates an impressive effect on wrist extension force and grip strength of patients with TE. Elbow taping also reduces pain at the lateral aspect of the elbow in these patients. PMID:24350156
Wangdell, Johanna; Carlsson, Gunnel; Fridén, Jan
To explore how surgical reconstruction of grip affects everyday life for patients with tetraplegia, with special emphasis on patients perspective of their perceived changes. Qualitative method. Eleven people (aged 22-73) with tetraplegia who had undergone surgical reconstruction to restore grip function. Qualitative interviews were conducted 7-17 months after surgery and analysed using Grounded theory. The core concept describing the participants experienced gains after grip reconstructive surgery was "enhanced independence". It was associated with changes in both practical and psychological aspects of independence. Practical aspects identified were: "perform more activities", "smoother everyday life", "renewed ability to participate in social activities", "less dependence on assistance" and "less restricted by physical environment". Psychological aspects of independence included "regained privacy", "increased manageability", "regained identity", "recapture a part of the body" and "share positive experiences with relatives and friends". Encompassing all categories was the concept "self-efficacy in hand control". It was seen as a result included in the enhanced independency core but also as an important factor for the development of all the other categories. Participants in this study experienced enhanced independence after grip reconstructive surgery and rehabilitation. The enhanced independence included both practical and physical aspects and it influenced all domains using the International Classification of Function, Disability and Health model; body function and structure, activities, participation, personal factors and environmental factors. Implications for Rehabilitation Patients with tetraplegia experience grip reconstruction as a useful intervention, an enhanced independence, related to their improved hand control. The increased hand control impacted not only physical aspects but also practical and psychological aspects. It also influenced social and
Belcher, Jewell G., Jr.; Vest, Thomas W.
Prosthetic hand with quick-grip/quick-release lever broadens range of specialized functions available to lower-arm amputee by providing improved capabilities for gripping rods, tools, handles, and like. Includes two stationary lower fingers opposed by one pivoting upper finger. Lever operates in conjunction with attached bracket.
Frank, Matthias; Hecht, Juliane; Napp, Matthias; Lange, Joern; Grossjohann, Rico; Stengel, Dirk; Schmucker, Uli; Ekkernkamp, Axel; Hinz, Peter
Although injuries due to circular saws are very common all over the world, there is surprisingly little information available about their functional outcomes. As the socioeconomic impact of these injuries is immense and determined by the casualties' disability and impairment, it is the objective of this study to present data on the functional outcome, disability, and impairment of hand injuries due to electric circular saws. Patients treated from 1999 through 2007 for circular saw-related hand injuries were contacted and asked for clinical follow-up assessment. The clinical follow-up protocol consisted of a physical examination and an assessment of static muscle power (grip and pinch strength). For assessment of the subjective experience of the patients regarding their injury-related disability and impairment, the DASH follow-up questionnaire was used. The occupational impact of these injuries was measured by number of lost working days. Finally, safety-related behaviour of the patients was investigated. 114 Patients were followed-up on average 52 months after the injury. Average in-house treatment was 8.8 days. Average time lost from work was 14.8 weeks. A significant reduction of static muscle testing parameters compared with the uninjured hand was revealed for grip strength, tip pinch, key pinch, and palmar pinch. Average DASH score was 17.4 (DASH work 15.8, DASH sports/music 17.7). Most patients had more than ten years experience in using these power tools. The everyday occurrence of circular saw-related hand injuries followed by relatively short periods of in-house treatment might distort the real dimension of the patients' remaining disability and impairment. While the trauma surgeon's view is generally confined to the patients' clinical course, the outcome parameters in this follow-up investigation, with loss of working time as the key factor, confirm that the whole socioeconomic burden is much greater than the direct cost of treatment.
Muoka, Polycarp I.; Haque, Md. Enamul; Gargoom, Ameen; Negnetvitsky, Michael
This paper presents a new photovoltaic (PV) power systems laboratory module that was developed to experimentally reinforce students' understanding of design principles, operation, and control of photovoltaic power conversion systems. The laboratory module is project-based and is designed to support a renewable energy course. By using MATLAB…
Malchaire, J.; Geng, Q.; Den Hartog, E.; Havenith, G.; Holmer, I.; Piette, A.; Powell, S.L.; Rintamäki, H.; Rissanen, S.
Objectives. At the request of the European Commission and in the framework of the European Machinery Directive, research was conducted jointly in five different laboratories to develop specifications for surface temperature limit values for the gripping and handling of cold items. Methods. Four
Malchaire, J.; Geng, Q.; Den Hartog, E.; Havenith, G.; Holmer, I.; Piette, A.; Powell, S.L.; Rintamäki, H.; Rissanen, S.
Objectives. At the request of the European Commission and in the framework of the European Machinery Directive, research was conducted jointly in five different laboratories to develop specifications for surface temperature limit values for the gripping and handling of cold items. Methods. Four hund
Kauffman, J.A.; Bazen, A.M.; Gerez, S.H.; Veldhuis, R.N.J.
This paper describes the design, implementation and evaluation of a user-verification system for a smart gun, which is based on grip-pattern recognition. An existing pressure sensor consisting of an array of 44 x 44 piezoresistive elements has been used. An interface has been developed to acquire pr
Technology roadmapping is a well-known tool for technology management, but practical advice for facilitating collaborative roadmapping workshops is relatively scarce. To cater for this need, we have designed a method for collaborative roadmapping, dubbed the GRIP method, for facilitating group work...
Farooq, Mohd; Khan, Abid Ali
This experiment was designed to know the effect of upper limb postural deviations on grip strength and grip endurance time. A full factorial design of experiment, i.e., 3 (0°, 45°, 90° abduction angles of upper arm) × 3 (45°, 90°, 135° angles of elbow flexion) × 3 (0°, -60° prone, +60° supine angles of forearm rotation) was used to find the effect of 27 combinations of postures on maximum voluntary contraction (MVC) grip strength and grip endurance time. The results showed that none of the main factors were significant on MVC grip, although there was a change in MVC grip. Grip endurance time significantly decreased with an increase in upper arm abduction. Also, grip endurance significantly increased with the elbow flexion angle and decreased with forearm rotation from neutral. These data will help designers and engineers to improve the workplace and tools to reduce the risk of injuries.
Mentiplay, Benjamin F; Perraton, Luke G; Bower, Kelly J; Adair, Brooke; Pua, Yong-Hao; Williams, Gavin P; McGaw, Rebekah; Clark, Ross A
Hand-held dynamometry (HHD) has never previously been used to examine isometric muscle power. Rate of force development (RFD) is often used for muscle power assessment, however no consensus currently exists on the most appropriate method of calculation. The aim of this study was to examine the reliability of different algorithms for RFD calculation and to examine the intra-rater, inter-rater, and inter-device reliability of HHD as well as the concurrent validity of HHD for the assessment of isometric lower limb muscle strength and power. 30 healthy young adults (age: 23±5 yrs, male: 15) were assessed on two sessions. Isometric muscle strength and power were measured using peak force and RFD respectively using two HHDs (Lafayette Model-01165 and Hoggan microFET2) and a criterion-reference KinCom dynamometer. Statistical analysis of reliability and validity comprised intraclass correlation coefficients (ICC), Pearson correlations, concordance correlations, standard error of measurement, and minimal detectable change. Comparison of RFD methods revealed that a peak 200 ms moving window algorithm provided optimal reliability results. Intra-rater, inter-rater, and inter-device reliability analysis of peak force and RFD revealed mostly good to excellent reliability (coefficients ≥ 0.70) for all muscle groups. Concurrent validity analysis showed moderate to excellent relationships between HHD and fixed dynamometry for the hip and knee (ICCs ≥ 0.70) for both peak force and RFD, with mostly poor to good results shown for the ankle muscles (ICCs = 0.31-0.79). Hand-held dynamometry has good to excellent reliability and validity for most measures of isometric lower limb strength and power in a healthy population, particularly for proximal muscle groups. To aid implementation we have created freely available software to extract these variables from data stored on the Lafayette device. Future research should examine the reliability and validity of these variables in clinical
Benjamin F Mentiplay
Full Text Available Hand-held dynamometry (HHD has never previously been used to examine isometric muscle power. Rate of force development (RFD is often used for muscle power assessment, however no consensus currently exists on the most appropriate method of calculation. The aim of this study was to examine the reliability of different algorithms for RFD calculation and to examine the intra-rater, inter-rater, and inter-device reliability of HHD as well as the concurrent validity of HHD for the assessment of isometric lower limb muscle strength and power.30 healthy young adults (age: 23±5 yrs, male: 15 were assessed on two sessions. Isometric muscle strength and power were measured using peak force and RFD respectively using two HHDs (Lafayette Model-01165 and Hoggan microFET2 and a criterion-reference KinCom dynamometer. Statistical analysis of reliability and validity comprised intraclass correlation coefficients (ICC, Pearson correlations, concordance correlations, standard error of measurement, and minimal detectable change.Comparison of RFD methods revealed that a peak 200 ms moving window algorithm provided optimal reliability results. Intra-rater, inter-rater, and inter-device reliability analysis of peak force and RFD revealed mostly good to excellent reliability (coefficients ≥ 0.70 for all muscle groups. Concurrent validity analysis showed moderate to excellent relationships between HHD and fixed dynamometry for the hip and knee (ICCs ≥ 0.70 for both peak force and RFD, with mostly poor to good results shown for the ankle muscles (ICCs = 0.31-0.79.Hand-held dynamometry has good to excellent reliability and validity for most measures of isometric lower limb strength and power in a healthy population, particularly for proximal muscle groups. To aid implementation we have created freely available software to extract these variables from data stored on the Lafayette device. Future research should examine the reliability and validity of these variables in
Bílý, Milan; Baláš, Jiří; Martin, Andrew John; Cochrane, Darryl; Coufalová, Klára; Süss, Vladimír
Issues of high levels of muscular asymmetry have been associated with injury risk, and therefore have potential implications for decremental performance at the elite sport level. The aim of this current study was to assess the relationship between the segmental fluid distribution and the paddle grip in elite male and female slalom kayakers and canoeists. Eighty-four world-cup competitors (61 males and 23 females) took part in the study. Impedance analysis was used to assess segmental fluid asymmetry. The effect of paddle grip (loose/fixed hand in kayakers, lower/upper hand in canoeists), morphological dominance (dominant/non-dominant) and discipline (canoe/kayak) were evaluated by repeated measures ANOVA. The findings indicated a significant effect of paddle grip in canoeists on morphological asymmetry in upper limbs (arm of lower paddle hand mean fluid distribution 3.28, s=0.43 litres; arm of upper paddle hand mean fluid distribution 3.19, s=0.41 litres; P=0.000, [Formula: see text]=0.33). The sternmen demonstrated higher asymmetry between the arms of upper and lower paddle hand (mean 0.11, s=0.04 litres, P=0.000, [Formula: see text]=0.80) than the bowmen (mean 0.04, s=0.06 litres, P=0.015, [Formula: see text]=0.44) in double-canoes. Significant morphological asymmetry was found also in kayakers but the effect of paddle grip was not substantial. The use of segmental impedance analysis may be a suitable diagnostic tool for assessing morphological changes, which can be related to paddling training. Likewise muscular asymmetry is associated with injury risk; the evaluation of morphological changes during the training process may be considered by sport trainers and physical therapists.
Zheng, Yang; Gao, Lin; Wang, Gang; Wang, Yingtuo; Yang, Zi; Wang, Xiuyue; Li, Tianqi; Dang, Chuan; Zhu, Ruohan; Wang, Jue
The mechanisms behind how muscle contractions in one hand influence corticomuscular coherence in the opposite hand are still undetermined. Twenty-two subjects were recruited to finish bimanual and unimanual motor tasks. In the unimanual tasks, subjects performed precision grip using their right hand with visual feedback of exerted forces. The bimanual tasks involved simultaneous finger abduction of their left hand with visual feedback and precision grip of their right hand. They were divided into four conditions according to the two contraction levels of the left-hand muscles and whether visual feedback existed for the right hand. Measures of coherence and power spectrum were calculated from EEG and EMG data and statistically analyzed to identify changes in corticomuscular coupling and oscillatory activity. Results showed that compared with the unimanual task, a significant increase in the mean corticomuscular coherence of the right hand was found when left-hand muscles contracted at 5% of the maximal isometric voluntary contraction (MVC). No significant changes were found when the contraction level was 50% of the MVC. Furthermore, both the increase of muscle contraction levels and the elimination of visual feedback for right hand can significantly decrease the corticomuscular coupling in right hand during bimanual tasks. In summary, the involvement of moderate left-hand muscle contractions resulted in an increase tendency of corticomuscular coherence in right hand while strong left-hand muscle contractions eliminated it. We speculated that the perturbation of activities in one corticospinal tract resulted from the movement of the opposite hand can enhance the corticomuscular coupling when attention distraction is limited. Copyright © 2016 Elsevier Ltd. All rights reserved.
Full Text Available Grip kinetics and their variation are emerging as important considerations in the clinical assessment of handwriting pathologies, fine motor rehabilitation, biometrics, forensics and ergonomic pen design. This study evaluated the intra- and inter-participant variability of grip shape kinetics in adults during signature writing. Twenty (20 adult participants wrote on a digitizing tablet using an instrumented pen that measured the forces exerted on its barrel. Signature samples were collected over 10 days, 3 times a day, to capture temporal variations in grip shape kinetics. A kinetic topography (i.e., grip shape image was derived per signature by time-averaging the measured force at each of 32 locations around the pen barrel. The normalized cross correlations (NCC of grip shape images were calculated within- and between-participants. Several classification algorithms were implemented to gauge the error rate of participant discrimination based on grip shape kinetics. Four different grip shapes emerged and several participants made grip adjustments (change in grip shape or grip height or rotated the pen during writing. Nonetheless, intra-participant variation in grip kinetics was generally much smaller than inter-participant force variations. Using the entire grip shape images as a 32-dimensional input feature vector, a K-nearest neighbor classifier achieved an error rate of 1.2±0.4% in discriminating among participants. These results indicate that writers had unique grip shape kinetics that were repeatable over time but distinct from those of other participants. The topographic analysis of grip kinetics may inform the development of personalized interventions or customizable grips in clinical and industrial applications, respectively.
Ghali, Bassma; Thalanki Anantha, Nayanashri; Chan, Jennifer; Chau, Tom
Grip kinetics and their variation are emerging as important considerations in the clinical assessment of handwriting pathologies, fine motor rehabilitation, biometrics, forensics and ergonomic pen design. This study evaluated the intra- and inter-participant variability of grip shape kinetics in adults during signature writing. Twenty (20) adult participants wrote on a digitizing tablet using an instrumented pen that measured the forces exerted on its barrel. Signature samples were collected over 10 days, 3 times a day, to capture temporal variations in grip shape kinetics. A kinetic topography (i.e., grip shape image) was derived per signature by time-averaging the measured force at each of 32 locations around the pen barrel. The normalized cross correlations (NCC) of grip shape images were calculated within- and between-participants. Several classification algorithms were implemented to gauge the error rate of participant discrimination based on grip shape kinetics. Four different grip shapes emerged and several participants made grip adjustments (change in grip shape or grip height) or rotated the pen during writing. Nonetheless, intra-participant variation in grip kinetics was generally much smaller than inter-participant force variations. Using the entire grip shape images as a 32-dimensional input feature vector, a K-nearest neighbor classifier achieved an error rate of 1.2±0.4% in discriminating among participants. These results indicate that writers had unique grip shape kinetics that were repeatable over time but distinct from those of other participants. The topographic analysis of grip kinetics may inform the development of personalized interventions or customizable grips in clinical and industrial applications, respectively.
Theorising power in student voice is contested terrain dominated by critical theory but challenged increasingly by post-structural approaches. Although critical approaches have suited the advocacy needed to establish student voice as worthy social justice work in this article I explore post-structural resources that more generatively account for…
Porcello, D.; Peticolas, L. M.; Schwerin, T. G.
The Lawrence Hall of Science (LHS) is University of California, Berkeley's public science center. Over the last decade, the Center for Technology Innovation at LHS has partnered with many institutions to establish a strong track record of developing successful technology solutions to support STEM teaching and learning within informal environments. Curation by subject-matter experts has been at the heart of many educational technology products from LHS and its partners that are directed at educators and families. This work includes: (1) popular digital libraries for inquiry-based activities at Howtosmile.org (NSF DRL #0735007) and NASA Earth and Space science education resources at NASAwavelength.org; and novel mobile apps like DIY Sun Science (NASA NNX10AE05G) and DIY Human Body (NIH 5R25OD010543) designed to scaffold exploration of STEM phenomena at home. Both NASA Wavelength and DIY Sun Science arose out of long-term collaborations with the Space Sciences Laboratory at UC Berkeley, Institute for Global Environmental Strategies (IGES), and other NASA-funded organizations, in partnership with NASA through cooperative agreements. This session will review the development, formative evaluation, and usage metrics for these two Earth and Space science-themed educational technology products directly relevant to the AGU community. Questions reviewed by presenters will include: What makes a good hands-on activity, and what essential information do educators depend on when searching for programming additions? What content and connections do families need to explore hands-on activities? How can technology help incorporate educational standards into the discovery process for learning experiences online? How do all these components drive the design and user experience of websites and apps that showcase STEM content?
Davies, Karen; Jagger, Carol; Kirkwood, Thomas B. L.; Syddall, Holly E.; Sayer, Avan A.
Background Weak grip strength (GS) is a key component of sarcopenia and frailty and a powerful predictor of mortality, morbidity and disability. Despite increasing interest in understanding GS across the lifespan, little is known about GS decline in the very old (aged ≥85). We examined trajectories of GS in very old adults and identified the determinants. Methods GS (kg) was measured four times over 5 years in 319 men and 526 women participating in the Newcastle 85+ Study. A weak GS sub-cohort was identified as having strength of ≤27 kg (men), and ≤16 kg (women) at baseline and follow-up. Mixed models were used to establish trajectories of GS and associated factors in all participants, men and women, and in those with weak GS. Results Men’s mean grip strength was 24.42 (SD = 6.77) kg, and women’s 13.23 (4.42) kg (p<0.001) at baseline, with mean absolute change of -5.27 (4.90) kg and -3.14 (3.41), respectively (p<0.001) by 5-year follow-up. In the time-only mixed model, men experienced linear annual decline in GS of -1.13 (0.8) kg (β (SE), p<0.001), whilst women’s decline although slower, accelerated by -0.06 (0.02) kg (p = 0.01) over time. In the saturated model, higher baseline physical activity, height, fat-free mass, better self-rated health, and not having arthritis in hand(s) were associated with stronger GS initially in both sexes. Annual GS decline in men and participants with weak GS who were highly physically active was slower by 0.95 and 0.52 kg, respectively compared with inactive counterparts. Conclusion Grip strength decline in the very old followed linear (men) and curvilinear (women) trends. High levels of physical activity were protective of GS loss in men (but not in women) and in those with weak GS. Thus maintaining muscle strength in later life is important to reduce the morbidity and mortality in the very old. PMID:27637107
expanding the instruments of national power to include such national capabilities as law enforcement, financial, and intelligence . Legally, this...of a single, civilian-led cyber agency that combines and consolidates the cyber functions of the Office of the Director of National Intelligence ...encouragement. Finally, I dedicate this effort to my wife and my three children . They give meaning and purpose to my life and I strive every day to
Liang, Nan; Takahashi, Makoto; Ni, Zhen; Yahagi, Susumu; Funase, Kozo; Kato, Takashi; Kasai, Tatsuya
Although there were many reports relating to intermanual transfer of behavioral motor tasks in humans, it is still not well-known whether the transfer phenomenon between the trained and untrained hand is accompanied by corresponding changes in motor system. In the present study we applied transcranial magnetic stimulation to investigate the practice effects of unilateral fingertip precision grip on corticospinal excitability, regarding both the trained and untrained hand muscles. The results showed that after practice fingertip grip force became steady and safety margin dramatically decreased not only in the trained hand, but also in the untrained hand. Regarding MEP and background EMG (B.EMG) activities, the regression slope of MEP/B.EMG ratio in the first dorsal interosseous (FDI) muscle became significantly steeper after practice in both hands, but in the thenar (TH) muscle there were no clear modulations. These results indicated that through practice qualitative or functional changes of corticospinal systems related to the reorganization for a fingertip precision grip prominently reflect only on FDI muscle which plays a dominant role in the task. More importantly, such effects were simultaneously seen in the untrained hand correspondent to the trained hand, i.e., changes of input-output property in M1 occur not only in the trained hand, but also in the untrained hand. Based on the present results, we suggest that training-induced neural adaptations of the central nervous system may include improvement of its predicting fingertip grip force for self-lifting of the object in the untrained hand.
Akhlaghi, Nima; Baker, Clayton A; Lahlou, Mohamed; Zafar, Hozaifah; Murthy, Karthik G; Rangwala, Huzefa S; Kosecka, Jana; Joiner, Wilsaan M; Pancrazio, Joseph J; Sikdar, Siddhartha
Surface electromyography (sEMG) has been the predominant method for sensing electrical activity for a number of applications involving muscle-computer interfaces, including myoelectric control of prostheses and rehabilitation robots. Ultrasound imaging for sensing mechanical deformation of functional muscle compartments can overcome several limitations of sEMG, including the inability to differentiate between deep contiguous muscle compartments, low signal-to-noise ratio, and lack of a robust graded signal. The objective of this study was to evaluate the feasibility of real-time graded control using a computationally efficient method to differentiate between complex hand motions based on ultrasound imaging of forearm muscles. Dynamic ultrasound images of the forearm muscles were obtained from six able-bodied volunteers and analyzed to map muscle activity based on the deformation of the contracting muscles during different hand motions. Each participant performed 15 different hand motions, including digit flexion, different grips (i.e., power grasp and pinch grip), and grips in combination with wrist pronation. During the training phase, we generated a database of activity patterns corresponding to different hand motions for each participant. During the testing phase, novel activity patterns were classified using a nearest neighbor classification algorithm based on that database. The average classification accuracy was 91%. Real-time image-based control of a virtual hand showed an average classification accuracy of 92%. Our results demonstrate the feasibility of using ultrasound imaging as a robust muscle-computer interface. Potential clinical applications include control of multiarticulated prosthetic hands, stroke rehabilitation, and fundamental investigations of motor control and biomechanics.
Moineau, G; Richou, J; Liot, M; Le Nen, D
Numerous procedures are in use to treat trapeziometacarpal osteoarthritis. Most of these techniques impair hand function. In a series of trapeziectomies stabilized by ligament reconstruction with tendon suspension, we investigated whether eventual parameters influenced hand function and dexterity. Some parameters influence hand function recovery following trapeziectomy combined to ligamento-tendinous stabilization. This is a continuous, retrospective, single surgeon series; 60 cases of thumb trapeziometacarpal osteoarthritis were treated with trapeziectomy and ligament reconstruction (40 palmaris longus, and 20 half flexor carpi radialis) with no additional metacarpophalangeal (MCP) joint surgery. Besides assessing classical clinical outcome criteria (pain, mobility, force), we analyzed hand function: this was obtained with a questionnaire about different everyday movements. Five types of grip were included in this analysis: spherical, pinch grasp, key pinch, power grip, and precision pinch. Fifty-one trapeziectomies (85%) were evaluated at an average follow-up of 7.5 years (5-11.5). Ninety-four percent of patients had good results for pain. The average Kapandji score for mobility was 9.6 (6-10) with a mean web angle at 36.5 degrees. Hyperextension of the MCP joint occurred in 36 cases and measured an average of 26 degrees (5 degrees-50 degrees). Compared to the contralateral side average strength was 97% with the Jamar dynamometer and 88% for the key pinch. The rate of satisfaction was 96%. Collapse of trapezial height was constant, and at last follow-up, the trapezial index was 50% of its preoperative initial value. The results relative to hand function assessment were good in 58% of patients. The spherical grip was the most difficult to restore. The analysis of the 42% of patients with average or poor hand function showed five prognostic factors for a poor outcome: young age at surgery, persisting postoperative pain, postoperative hyperextension of the MCP joint
Wu, Xianwei; Jin, Wenguang
Human-Computer Interaction (HCI) raises demand of convenience, endurance, responsiveness and naturalness. This paper describes a design of a compact wearable low-power HCI equipment applied to gesture recognition. System combines multi-mode sense signals: the vision sense signal and the motion sense signal, and the equipment is equipped with the depth camera and the motion sensor. The dimension (40 mm × 30 mm) and structure is compact and portable after tight integration. System is built on a module layered framework, which contributes to real-time collection (60 fps), process and transmission via synchronous confusion with asynchronous concurrent collection and wireless Blue 4.0 transmission. To minimize equipment's energy consumption, system makes use of low-power components, managing peripheral state dynamically, switching into idle mode intelligently, pulse-width modulation (PWM) of the NIR LEDs of the depth camera and algorithm optimization by the motion sensor. To test this equipment's function and performance, a gesture recognition algorithm is applied to system. As the result presents, general energy consumption could be as low as 0.5 W.
Mainous, Arch G; Tanner, Rebecca J; Anton, Stephen D; Jo, Ara
Muscle strength may play a role in cardiometabolic disease. We examined the relationship between hand grip strength and diabetes and hypertension in a sample of healthy weight adults. In 2015, we analyzed the National Health and Nutrition Examination Survey 2011-2012 for adults aged ≥20 years with healthy BMIs (between 18.5 and Hypertension was based on measured blood pressure and reported hypertension diagnosis. Individuals with undiagnosed diabetes compared with individuals without diabetes had lower grip strength (51.9 vs 69.8, p=0.0001), as did individuals with diagnosed diabetes compared with individuals without diabetes (61.7 vs 69.8, p=0.008). Mean grip strength was lower among individuals with undiagnosed hypertension compared with individuals without hypertension (63.5 vs 71.5, p=0.008) as well as among individuals with diagnosed hypertension compared with those without hypertension (60.8 vs 71.5, phypertension (β=-6.6, p=0.004) and diagnosed hypertension (β=-4.27, p=0.04) compared with individuals without hypertension. Among healthy weight adults, combined grip strength is lower in individuals with diagnosed and undiagnosed diabetes and hypertension. Copyright © 2015 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.
Ameli, Mitra; Dafotakis, Manuel; Fink, Gereon R; Nowak, Dennis A
We tested the ability of healthy participants to learn an association between arbitrary sensory cues and the weight of an object to be lifted using a precision grip between the index finger and thumb. Right-handed participants performed a series of grip-lift tasks with each hand. In a first experiment, participants lifted two objects of equal visual appearance which unexpectedly and randomly changed their weight. In two subsequent experiments, the change in object weight was indicated by cues, which were presented (i) visually or (ii) auditorily. When no cue about the weight of the object to be lifted was presented, participants programmed grip force according to the most recent lift, regardless of the hand used. In contrast, participants were able to rapidly establish an association between a particular sensory cue with a given weight and scaled grip force precisely to the actual weight thereafter, regardless of the hand used or the sensory modality of the cue. We discuss our data within the theoretical concept of internal models.
Dispa, Delphine; Lejeune, Thierry; Thonnard, Jean-Louis
Most chronic stroke patients present with difficulty in the manipulation of objects. The aim of this study was to test whether an intensive program of precision grip training could improve hand functioning of patients at more than 6 months after a stroke. This was a cross-over study; hence, at inclusion, the patients were randomly divided into two…
Scott, Rollin L.
During the course of the Kennedy Space Center Summer Internship, two main experiments were performed: The Vacuum-Compacted Regolith Gripping Mechanism and Unmanned Flights via Quad-copters. The objectives of the Vacuum-Compacted Regolith Gripping Mechanism, often abbreviated as the Granular Gripper, are to exhibit Space Technology, such as a soft robotic hand, lift different apparatuses used to excavate regolith, and conserve energy while executing its intended task. The project is being conducted to test how much weight the Granular Gripper can hold. With the use of an Animatronic Robotic Hand, Arduino Uno, and other components, the system was calibrated before actually conducting the intended weight test. The maximum weight each finger could hold with the servos running, in the order of pinky, ring, middle, and index fingers, are as follows: 1.340N, 1.456 N, 0.9579 N, and 1.358 N. Using the small vacuum pump system, the maximum weight each finger could hold, in the same order, was: 4.076 N, 6.159 N, 5.454 N, and 4.052 N. The maximum torques on each of the fingers when the servos were running, in the same respective order, was: 0.0777 Nm, 0.0533 Nm, 0.0648 Nm, and 0.0532 Nm. The maximum torques on the individual fingers, when the small vacuum pump was in effect, in the same order as above, was: 0.2318 Nm, 0.3032 Nm, 0.2741 Nm, and 0.1618 Nm. In testing all the fingers with the servos running, the total weight was 5.112 N and the maximum torque on the all the fingers was 0.2515 Nm. However, when the small vacuum pump system was used, the total weight was 19.741 N and the maximum torque on the all the fingers was 0.9713 Nm. The conclusion that was drawn stated that using the small vacuum pump system proved nearly 4 times more effective when testing how much weigh the hand could hold. The resistance provided by the compacted sand in the glove allowed more weight to be held by the hand and glove. Also, when the servos turned off and the hand still retaining its
Cavina-Pratesi, Cristiana; Monaco, Simona; Fattori, Patrizia; Galletti, Claudio; McAdam, Teresa D; Quinlan, Derek J; Goodale, Melvyn A; Culham, Jody C
Picking up a cup requires transporting the arm to the cup (transport component) and preshaping the hand appropriately to grasp the handle (grip component). Here, we used functional magnetic resonance imaging to examine the human neural substrates of the transport component and its relationship with the grip component. Participants were shown three-dimensional objects placed either at a near location, adjacent to the hand, or at a far location, within reach but not adjacent to the hand. Participants performed three tasks at each location as follows: (1) touching the object with the knuckles of the right hand; (2) grasping the object with the right hand; or (3) passively viewing the object. The transport component was manipulated by positioning the object in the far versus the near location. The grip component was manipulated by asking participants to grasp the object versus touching it. For the first time, we have identified the neural substrates of the transport component, which include the superior parieto-occipital cortex and the rostral superior parietal lobule. Consistent with past studies, we found specialization for the grip component in bilateral anterior intraparietal sulcus and left ventral premotor cortex; now, however, we also find activity for the grasp even when no transport is involved. In addition to finding areas specialized for the transport and grip components in parietal cortex, we found an integration of the two components in dorsal premotor cortex and supplementary motor areas, two regions that may be important for the coordination of reach and grasp.
... Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is a Hand Surgeon? What is ... by exercises designed to stretch and strengthen the muscles and tendons, which can be recommended by a hand therapist. Changing grips on the golf club may ...
Full Text Available Background: Tennis elbow (TE is a common musculotendinous degenerative disorder of the extensor origin at the lateral humeral epicondyle. Different modes of treatment are used for management of tennis elbow.Objectives: This study investigated the effect of the taping technique (TT on pain, grip strength and wrist extension force in treatment of tennis elbow.Patients and Methods: Thirty patients (16 men /14 women with a mean age of 32.2 years with tennis elbow of their dominant arm participated in this study. Outcome measures were assessment of pain at the lateral aspect of the elbow, grip strength and wrist extension force before and five to ten minutes after application of elbow tape on the affected and unaffected arms. A Visual Analog Scale was used to assess pain. A dynamometer and a hand-held dynamometer were used for evaluation of grip strength and wrist extension force, respectively.Results: Among the variables, significant differences were found in wrist extension forces between effected and unaffected arms (P = 0.02. Changes in grip strength showed statically significant improvements in the affected arm compared to the unaffected arm (P = 0.03. Also, in assessment of pain at the lateral epicondyle, the mean change between affected and unaffected arms was significant, with P = 0.001.Conclusions: The taping technique, as applied in this study demonstrates an impressive effect on wrist extension force and grip strength of patients with TE. Elbow taping also reduces pain at the lateral aspect of the elbow in these patients.
Merriam, Ezekiel G.; Berg, Andrew B.; Willig, Andrew; Parness, Aaron; Frey, Tim; Howell, Larry L.
This paper details the development and early testing of a compliant suspension for a microspine gripper device for asteroid capture or micro-gravity percussive drilling. The microspine gripper architecture is reviewed, and a proposed microspine suspension design is presented and discussed. Prototyping methods are discussed, as well as testing methods and results. A path forward is identified from the results of the testing completed thus far. Key findings include: the microspine concept has been established as a valid architecture and the compliant suspension exhibits the desired stiffness characteristics for good gripping behavior. These developments will aid in developing the capability to grasp irregularly shaped boulders in micro-gravity.
Full Text Available Grip1 Blood + mm9 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Grip1.1.tsv... http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Grip1.5.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Gri...p1.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Grip1.Blood.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Blood.gml ...
Schreuders, Ton; Roebroeck, Marij; Jaquet, Jean; Hovius, Steven; Stam, Henk
textabstractObjective: To compare the outcome of muscle strength with manual muscle strength testing grip and pinch strength measurements and a dynamometer which allows for measurements of the intrinsic muscles of the hand in isolation (the Rotterdam Intrinsic Hand Myometer, RIHM). Methods: Thirty-four patients more than 2 years after ulnar and/or median nerve injury. Muscle strength was evaluated using manual muscle strength testing (MMST), grip, pinch and intrinsic muscle strength measureme...
Bass, Andrew H., Jr.
Basic hand grips and sensor interactions that a dextrous robot hand will need as part of the operation of an EVA Retriever are analyzed. What is to be done with a dextrous robot hand is examined along with how such a complex machine might be controlled. It was assumed throughout that an anthropomorphic robot hand should perform tasks just as a human would; i.e., the most efficient approach to developing control strategies for the hand would be to model actual hand actions and do the same tasks in the same ways. Therefore, basic hand grips that human hands perform, as well as hand grip action were analyzed. It was also important to examine what is termed sensor fusion. This is the integration of various disparate sensor feedback paths. These feedback paths can be spatially and temporally separated, as well as, of different sensor types. Neural networks are seen as a means of integrating these varied sensor inputs and types. Basic heuristics of hand actions and grips were developed. These heuristics offer promise of control dextrous robot hands in a more natural and efficient way.
Kim, Gi-Wook; Ko, Myoung-Hwan
Previous studies have established that transcranial direct current stimulation (tDCS) is a powerful technique for the deliberate manipulation of the activity of human cerebral cortex. Moreover, it has also been shown that the non-exhausted voluntary motor exercise increases the excitability of corticospinal tract. We conducted this study to define the facilitation effect following anodal tDCS combined with the voluntary grip exercise as compared with single use of tDCS or voluntary grip exercise. Our result showed that the combination of anodal tDCS with voluntary grip exercise produced a 2-fold increase in the amplitude of MEP as compared with single use of anodal tDCS or voluntary grip exercise. In conclusion, our result could indicate that the treatment outcomes of brain and neurorehabilitation using tDCS would be better when tDCS is combined with the appropriate method of voluntary exercise as compared with single use of tDCS. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.
Erik D. Engeberg
Full Text Available Eight human test subjects attempted to track a desired position trajectory with an instrumented manipulandum (MN. The test subjects used the MN with three different levels of stiffness. A transfer function was developed to represent the human application of a precision grip from the data when the test subjects initially displaced the MN so as to learn the position mapping from the MN onto the display. Another transfer function was formed from the data of the remainder of the experiments, after significant displacement of the MN occurred. Both of these transfer functions accurately modelled the system dynamics for a portion of the experiments, but neither was accurate for the duration of the experiments because the human grip dynamics changed while learning the position mapping. Thus, an adaptive system model was developed to describe the learning process of the human test subjects as they displaced the MN in order to gain knowledge of the position mapping. The adaptive system model was subsequently validated following comparison with the human test subject data. An examination of the average absolute error between the position predicted by the adaptive model and the actual experimental data yielded an overall average error of 0.34mm for all three levels of stiffness.
Bedell, Susanna E; Graboys, Thomas B
Examination of the hands has the potential to transform the encounter between physician and patient. Taking the hands conveys a sense of warmth and connectedness and is a means to communicate the physician's mindfulness. The hands can focus the examination on the individual patient as a complete human being, and not merely a disease or a collection of symptoms. The hands provide readily accessible information that may not be available through other evaluations, and they offer clues to a patient's physical and mental health. Commonplace observations, such as those revealed in the hands, can unravel medical mysteries and provide profound clinical insights.
Kloosterman, Marieke G M; Buurke, Jaap H; de Vries, Wiebe; Van der Woude, Lucas H V; Rietman, Johan S
This study aims to compare hand-rim and power-assisted hand-rim propulsion on potential risk factors for shoulder overuse injuries: intensity and repetition of shoulder loading and force generation in the extremes of shoulder motion. Eleven experienced hand-rim wheelchair users propelled an instrumented wheelchair on a treadmill while upper-extremity kinematic, kinetic and surface electromyographical data was collected during propulsion with and without power-assist. As a result during power-assisted propulsion the peak resultant force exerted at the hand-rim decreased and was performed with significantly less abduction and internal rotation at the shoulder. At shoulder level the anterior directed force and internal rotation and flexion moments decreased significantly. In addition, posterior and the minimal inferior directed forces and the external rotation moment significantly increased. The stroke angle decreased significantly, as did maximum shoulder flexion, extension, abduction and internal rotation. Stroke-frequency significantly increased. Muscle activation in the anterior deltoid and pectoralis major also decreased significantly. In conclusion, compared to hand-rim propulsion power-assisted propulsion seems effective in reducing potential risk factors of overuse injuries with the highest gain on decreased range of motion of the shoulder joint, lower peak propulsion force on the rim and reduced muscle activity.
Veldhuis, Raymond; Bazen, Asker; Kauffman, Joost; Hartel, Pieter
This paper describes the design, implementation and evaluation of a user-verification system for a smart gun, which is based on grip-pattern recognition. An existing pressure sensor consisting of an array of 44 £ 44 piezoresistive elements is used to measure the grip pattern. An interface has been d
Veldhuis, Raymond N.J.; Bazen, A.M.; Kauffman, J.A.; Hartel, Pieter H.; Delp, Edward J.; Wong, Ping W.
This paper describes the design, implementation and evaluation of a user-verification system for a smart gun, which is based on grip-pattern recognition. An existing pressure sensor consisting of an array of 44 x 44 piezoresistive elements is used to measure the grip pattern. An interface has been
Shang, X.; Groenland, J.P.J.; Groenland, J.P.J.; Veldhuis, Raymond N.J.
In the biometric verification system of a smart gun, the rightful user of the gun is recognized based on grip-pattern recognition. It was found that the verification performance of grip-pattern recognition degrades strongly when the data for training and testing the classifier, respectively, have
Lewis, E A; Sheredos, C R; Sowell, T T; Houston, V L
The results have been presented of a 2-year survey designed to determine whether external power systems offer a significant contribution to the needs of the upper-limb amputee or whether they represent novelties duplicating the functions of conventional mechanical components. The following conclusions have been drawn: 1. External power does offer advantages to the arm amputee. Myoelectric control, especially combined with a self-suspending socket, offers an otherwise normal partial forearm amputee better function without the necessity of a harness. External power, especially for the short partial or total arm amputee and others with limited excursion, brings increased function with less effort. For these patients the advantages of such components as the electric elbow outweigh the recent disadvantages. 2. The components evaluated in this Study are not without limitations. Maintenance requirements of the VA Elbow were excessive. The VA Elbow should not be prescribed for patients who do heavy work with their prostheses because the flexspline may break. Regarding such concerns as lack of sensory feedback, noise, weight, and flexion/extension speed, the advantages of each unit must be weighed against the disadvantages with preference to the individual amputee. 3. The endoskeletal forearm with soft cover is an advantage because of its lightness and cosmesis. 4. Because of the many malfunctions attributed to prosthetist errors, the need is evident for thorough specialized education in the field of external power. A few centralized fabrication facilities may be desirable as opposed to fabrication by many facilities with limited experience. Modular components that are interchangeable and field repairable would be desirable. The systems should be fitted, installed and repaired only by trained prosthetists who have successfully completed a course in externally powered upper-limb prostheses. All members of the Clinic Team should be thoroughly educated in external power as it
Dec 15, 2009 ... The data of collision-mechanical property of tomatoes gripped by robot fingers are important for the gripping control of .... Figure 2a shows the process of robot fingers gripping tomato. ..... Drop test simulation of a sample.
Mukherjee, D. J.
Fifty cases of tetraplegia have been treated in the Spinal Cord Injury Centre, Military Hospital, Kirkee, during the past 4 years. Twelve patients have been treated by tendon transfer of the hand to give a pinch grip. They have been made more independent and can be rehabilitated better socially. This has been found better than using any splint continuously.
Get to grips with a new technology, understand what it is and what it can do for you, and then get to work with the most important features and tasks. A practical, hands-on tutorial approach that explores the concepts of PowerShell in a friendly manner, taking an adhoc approach to each topic.If you are an administrator who is new to PowerShell or are looking to get a good grounding in these new features, this book is ideal for you. It's assumed that you will have some experience in PowerShell and Windows Server, as well being familiar with the PowerShell command-line.
Nelson, Rohan; Howden, Mark; Hayman, Peter
This paper explores heuristic methods with potential to place the analytical power of real options analysis into the hands of natural resource managers. The complexity of real options analysis has led to patchy or ephemeral adoption even by corporate managers familiar with the financial-market origins of valuation methods. Intuitively accessible methods for estimating the value of real options have begun to evolve, but their evaluation has mostly been limited to researcher-driven applications. In this paper we work closely with Bush Heritage Australia to evaluate the potential of real options analysis to support the intuitive judgement of conservation estate managers in covenanting land with uncertain future conservation value due to climate change. The results show that modified decision trees have potential to estimate the option value of covenanting individual properties while time and ongoing research resolves their future conservation value. Complementing this, Luehrman's option space has potential to assist managers with limited budgets to increase the portfolio value of multiple properties with different conservation attributes.
Costache, Andrei; Glejbøl, Kristian; Sivebæk, Ion Marius
Flexible risers are used in the oil industry to transport liquids and gas from the seafloorto extraction and production equipment at the sea surface. Ongoing research aims at using composite materials instead of steel, in order to reduce weight and increase stiffness. Ensuring an optimal load...... transfer between the composite and metal components is very important. This paper presents an improved method for anchoring a flat fiber reinforced tendon using a double grip system with self-locking grips. The novelty is the combination of new experimental results and finite element (FE) analysis...... to develop asuperior dry friction grip. Experimental results are carried using a dedicated test setup, through which the test parameters can be accurately controlled. The efficiency of the grip system during pullout is superior to results obtained with flat grips. Numerical results offer an in...
Full Text Available Abstract Background Although injuries due to circular saws are very common all over the world, there is surprisingly little information available about their functional outcomes. As the socioeconomic impact of these injuries is immense and determined by the casualties' disability and impairment, it is the objective of this study to present data on the functional outcome, disability, and impairment of hand injuries due to electric circular saws. Methods Patients treated from 1999 through 2007 for circular saw-related hand injuries were contacted and asked for clinical follow-up assessment. The clinical follow-up protocol consisted of a physical examination and an assessment of static muscle power (grip and pinch strength. For assessment of the subjective experience of the patients regarding their injury-related disability and impairment, the DASH follow-up questionnaire was used. The occupational impact of these injuries was measured by number of lost working days. Finally, safety-related behaviour of the patients was investigated. Results 114 Patients were followed-up on average 52 months after the injury. Average in-house treatment was 8.8 days. Average time lost from work was 14.8 weeks. A significant reduction of static muscle testing parameters compared with the uninjured hand was revealed for grip strength, tip pinch, key pinch, and palmar pinch. Average DASH score was 17.4 (DASH work 15.8, DASH sports/music 17.7. Most patients had more than ten years experience in using these power tools. Conclusion The everyday occurrence of circular saw-related hand injuries followed by relatively short periods of in-house treatment might distort the real dimension of the patients' remaining disability and impairment. While the trauma surgeon's view is generally confined to the patients' clinical course, the outcome parameters in this follow-up investigation, with loss of working time as the key factor, confirm that the whole socioeconomic burden is much
Full Text Available We investigated the purported association between developmental changes in grip selection planning and improvements in an individual’s capacity to represent action at an internal level (i.e., motor imagery. Participants were groups of healthy children aged 6-7 years and 8-12 years respectively, while a group of adolescents (13-17 years and adults (18-34 years allowed for consideration of childhood development in the broader context of motor maturation. A group of children aged 8-12 years with probable DCD (pDCD was included as a reference group for atypical motor development. Participants’ proficiency to generate and/or engage internal action representations was inferred from performance on the hand rotation task, a well-validated measure of motor imagery. A grip selection task designed to elicit the end-state comfort (ESC effect provided a window into the integrity of grip selection planning. Consistent with earlier accounts, the efficiency of grip selection planning followed a non-linear developmental progression in neurotypical individuals. As expected, analysis confirmed that these developmental improvements were predicted by an increased capacity to generate and/or engage internal action representations. The profile of this association remained stable throughout the (typical developmental spectrum. These findings are consistent with computational accounts of action planning that argue that internal action representations are associated with the expression and development of grip selection planning across typical development. However, no such association was found for our sample of children with pDCD, suggesting that individuals with atypical motor skill may adopt an alternative, sub-optimal strategy to plan their grip selection compared to their same-age control peers.
Fuelscher, Ian; Williams, Jacqueline; Wilmut, Kate; Enticott, Peter G.; Hyde, Christian
We investigated the purported association between developmental changes in grip selection planning and improvements in an individual’s capacity to represent action at an internal level [i.e., motor imagery (MI)]. Participants were groups of healthy children aged 6–7 years and 8–12 years respectively, while a group of adolescents (13–17 years) and adults (18–34 years) allowed for consideration of childhood development in the broader context of motor maturation. A group of children aged 8–12 years with probable DCD (pDCD) was included as a reference group for atypical motor development. Participants’ proficiency to generate and/or engage internal action representations was inferred from performance on the hand rotation task, a well-validated measure of MI. A grip selection task designed to elicit the end-state comfort (ESC) effect provided a window into the integrity of grip selection planning. Consistent with earlier accounts, the efficiency of grip selection planning followed a non-linear developmental progression in neurotypical individuals. As expected, analysis confirmed that these developmental improvements were predicted by an increased capacity to generate and/or engage internal action representations. The profile of this association remained stable throughout the (typical) developmental spectrum. These findings are consistent with computational accounts of action planning that argue that internal action representations are associated with the expression and development of grip selection planning across typical development. However, no such association was found for our sample of children with pDCD, suggesting that individuals with atypical motor skill may adopt an alternative, sub-optimal strategy to plan their grip selection compared to their same-age control peers. PMID:26903915
Brokaw, Elizabeth B; Black, Iian; Holley, Rahsaan J; Lum, Peter S
Stroke patients often have flexor hypertonia and finger extensor weakness, which makes it difficult to open their affected hand for functional grasp. Because of this impairment, hand rehabilitation after stroke is essential for restoring functional independent lifestyles. The goal of this study is to develop a passive, lightweight, wearable device to assist with hand function during performance of activities of daily living. The device, Hand Spring Operated Movement Enhancer (HandSOME), assists with opening the patient's hand using a series of elastic cords that apply extension torques to the finger joints and compensates for the flexor hypertonia. Device design and calibration are described as well as functional and usability testing with stroke subjects with a wide range of hand impairments. In initial testing with eight stroke subjects with finger flexor hypertonia, use of the HandSOME significantly increased range of motion and functional ability (p=0.002) . There was some decrease in grip strength with the HandSOME device at the subject's ideal setting, however this was not statistically significant (p=0.167) and did not seem to have a significant effect on function. Overall HandSOME shows promise as a training tool to facilitate repetitive task practice for improving hand function in stroke patients. HandSOME can be used as part of a home-based therapy program, or as an orthotic for replacing lost function.
Shechtman, Orit; Goodall, Sara K
The purpose of the present study was to determine if the administration and interpretation of the rapid exchange grip (REG) test vary among hand therapists nationally. The REG is used to determine sincerity of effort of grip strength. There are inconsistencies in the literature regarding the administration and interpretation of the REG, as various studies use different testing protocols and diverse interpretation criteria for what constitutes a sincere effort. As a result, we expected to find a lack of standardization in the administration and interpretation of the REG in clinical practice. We conducted a random nationwide survey of 200 hand therapists. The questionnaire items regarding the administration of the REG included patient position, test instructions, handle settings, handling of the dynamometer, hand switch rate, number of repetitions, and techniques used to record the score. The items for the interpretation of the REG involved questions regarding comparative tests. We found that the REG test lacks standardized administration protocols and interpretation criteria among therapists nationwide. The lack of standardization is likely to affect the reliability and validity of the REG and to hinder the therapist's ability to accurately report its outcomes. The implications of lack of standardization in assessment techniques to the profession are discussed.
Schabrun, Siobhan M; Stinear, Cathy M; Byblow, Winston D; Ridding, Michael C
Task-specific focal dystonia is thought to have a neurological basis where stereotypical synchronous inputs and maladaptive plasticity play a role. As afferent input is a powerful driver of cortical reorganization, we propose that a period of asynchronous afferent stimulation may reverse maladaptive cortical changes and alleviate symptoms. Using transcranial magnetic stimulation (TMS), 3 hand muscles were mapped in 10 dystonics and 10 healthy controls. Mapping occurred before and after 1 h of nonassociative stimulation (NAS) to first dorsal interosseous (FDI) and abductor pollicis brevis (APB). Participants performed grip lift, handwriting, and cyclic drawing before and after NAS. Prior to NAS, dystonics had larger maps, and the centers of gravity (CoGs) of the FDI and APB maps were closer together. Dystonics demonstrated impairments in grip-lift, handwriting, and cyclic drawing tasks. Following NAS, map size was reduced in all muscles in dystonic participants and FDI and APB CoGs moved further apart. Among dystonics, NAS produced a reduction in movement variability during cyclic drawing. Thus, 1 h of NAS can reduce the magnitude, and increase the separation, of TMS representational maps. We suggest that these changes reflect some normalization of the representational abnormalities seen in focal dystonia and provide initial, limited evidence that such changes are associated with improvements in circle drawing.
Full Text Available Background: There are various studies using Mulligan’s MWM with or without combining with electrotherapy modalities and proved the efficacy of the technique in immediately decreasing pain and improving grip strength in patients with lateral epicondylitis. Orthotic as a treatment is also proved to be beneficial in decreasing pain and improving grip strength. There is evidence that housewives are prone to develop lateral epicondylitis due to their routine household work. But there is lack of evidence which compare initial effects of MWM and orthosis in housewives bringing up better outcome measures. The purpose of this study is to compare the initial effectiveness of Mulligan’s MWM and elbow orthosis on pain and grip strength in housewives with lateral epicondylitis. The aim of the study is to evaluate the effectiveness of Mulligan’s MWM technique versus counterforce elbow orthosis in immediately reducing pain and improving grip strength in lateral epicondylitis in housewives. Methodos: All subjects underwent a pre-treatment examination to assess pain and pain free hand grip strength with the help of outcome measures. Subjects were randomly assigned into two groups, A and B respectively; having 25 subjects in each group. Group A was treated with one session of Mulligan’s MWM technique. Group B was treated with Counterforce elbow strap orthosis. Data was assessed pre-treatment and immediately after treatment. Visual Analogue Scale (VAS and hand grip on Hand Grip Dynamometer (HGD were used as outcome measures. Results: Independent t-test was performed to see the effectiveness between Mulligan’s MWM and elbow orthosis. For VAS, t = - 2.243 which is significant at 5% level of significance. It has been inferred that VAS decreases more when Mulligan’s MWM was applied. For HGD, t = 0.878 which is not significant implying that increase in HGD do not differ remarkably for the two treatments. Conclusion: It has been recorded from the study that
Full Text Available Background. Connectivity-based predictions of hand motor outcome have been proposed to be useful in stroke patients. We intended to assess the prognostic value of different imaging methods on short-term (3 months and long-term (6 months motor outcome after stroke. Methods. We measured resting state functional connectivity (rsFC, diffusion weighted imaging (DWI and grip strength in 19 stroke patients within the first days (5-9 days after stroke. Outcome measurements for short-term (3 months and long-term (6 months motor function was assessed by the Motricity Index (MI of the upper limb and the Box and Block test (BB. Patients were predominantly mildly affected since signed consent was necessary at inclusion. We performed a multiple stepwise regression analysis to compare the predictive value of rsFC, DWI and clinical measurements. Results. Patients showed relevant improvement in both motor outcome tests. As expected grip strength at inclusion was a predictor for short- and long-term motor outcome as assessed by MI. Diffusion-based tract volume (DTV of the tracts between ipsilesional primary motor cortex and contralesional anterior cerebellar hemisphere showed a strong trend (p=0.05 for a predictive power for long-term motor outcome as measured by MI. DTV of the interhemispheric tracts between both primary motor cortices was predictive for both short - and long-term motor outcome in BB. rsFC was not associated with motor outcome. Conclusions. Grip strength is a good predictor of hand motor outcome concerning strength-related measurements (MI for mildly affected subacute patients. Therefore additional connectivity measurements seem to be redundant in this group. Using more complex movement recruiting bilateral motor areas as an outcome parameter, DTV and in particular interhemispheric pathways might enhance predictive value of hand motor outcome.
Matthew R Williams
Full Text Available The loss of a hand can greatly affect quality of life. A prosthetic device that can mimic normal hand function is very important to physical and mental recuperation after hand amputation, but the currently available prosthetics do not fully meet the needs of the amputee community. Most prosthetic hands are not dexterous enough to grasp a variety of shaped objects, and those that are tend to be heavy, leading to discomfort while wearing the device. In order to attempt to better simulate human hand function, a dexterous hand was developed that uses an over-actuated mechanism to form grasp shape using intrinsic joint mounted motors in addition to a finger tendon to produce large flexion force for a tight grip. This novel actuation method allows the hand to use small actuators for grip shape formation, and the tendon to produce high grip strength. The hand was capable of producing fingertip flexion force suitable for most activities of daily living. In addition, it was able to produce a range of grasp shapes with natural, independent finger motion, and appearance similar to that of a human hand. The hand also had a mass distribution more similar to a natural forearm and hand compared to contemporary prosthetics due to the more proximal location of the heavier components of the system. This paper describes the design of the hand and controller, as well as the test results.
Williams, Matthew R; Walter, Wayne
The loss of a hand can greatly affect quality of life. A prosthetic device that can mimic normal hand function is very important to physical and mental recuperation after hand amputation, but the currently available prosthetics do not fully meet the needs of the amputee community. Most prosthetic hands are not dexterous enough to grasp a variety of shaped objects, and those that are tend to be heavy, leading to discomfort while wearing the device. In order to attempt to better simulate human hand function, a dexterous hand was developed that uses an over-actuated mechanism to form grasp shape using intrinsic joint mounted motors in addition to a finger tendon to produce large flexion force for a tight grip. This novel actuation method allows the hand to use small actuators for grip shape formation, and the tendon to produce high grip strength. The hand was capable of producing fingertip flexion force suitable for most activities of daily living. In addition, it was able to produce a range of grasp shapes with natural, independent finger motion, and appearance similar to that of a human hand. The hand also had a mass distribution more similar to a natural forearm and hand compared to contemporary prosthetics due to the more proximal location of the heavier components of the system. This paper describes the design of the hand and controller, as well as the test results.
A robotic multi tool gripper design and implementation is presented in this paper. The proposed design targets applications where an actuation task is performed using a wide selection of standard hand tools. The manipulation motion is assumed to be rotational which requires a firm grip to account for external torque on the grasped tool. The setup is assumed to be a conventional workshop panel with hand tools being hanged close to each other, which constraints lateral clearance around the target, and near the wall of the panel, which constraints the depth clearance. Off the shelf grippers are mostly heavy and bulky which make them unsuitable for these requirements. Moreover, they are not optimized in terms of power consumption, simplicity and compactness. These generic grippers are mostly designed for pick and place tasks where no external torques other than those caused by the object weight affects the gripper. The design challenge involves building a gripper that is capable of operating in limited clearance space, firmly grip a variety of standard hand tools with different sizes and shapes. The proposed design is optimized for these objectives and offers a low cost and power consumption solution. The design has been validated in lab and outdoor experiments and has been deployed in real operating platform used in an international robotics competition.
van Elk, Michiel; Bousardt, Roel; Bekkering, Harold; van Schie, Hein T
Detecting errors in other's actions is of pivotal importance for joint action, competitive behavior and observational learning. Although many studies have focused on the neural mechanisms involved in detecting low-level errors, relatively little is known about error-detection in everyday situations. The present study aimed to identify the functional and neural mechanisms whereby we understand the correctness of other's actions involving well-known objects (e.g. pouring coffee in a cup). Participants observed action sequences in which the correctness of the object grasped and the grip applied to a pair of objects were independently manipulated. Observation of object violations (e.g. grasping the empty cup instead of the coffee pot) resulted in a stronger P3-effect than observation of grip errors (e.g. grasping the coffee pot at the upper part instead of the handle), likely reflecting a reorienting response, directing attention to the relevant location. Following the P3-effect, a parietal slow wave positivity was observed that persisted for grip-errors, likely reflecting the detection of an incorrect hand-object interaction. These findings provide new insight in the functional significance of the neurophysiological markers associated with the observation of incorrect actions and suggest that the P3-effect and the subsequent parietal slow wave positivity may reflect the detection of errors at different levels in the action hierarchy. Thereby this study elucidates the cognitive processes that support the detection of action violations in the selection of objects and grips.
Hobbs Sarah Jane
Full Text Available Since the ability to train the horse to be ambidextrous is considered highly desirable, rider asymmetry is recognized as a negative trait. Acquired postural and functional asymmetry can originate from numerous anatomical regions, so it is difficult to suggest if any is developed due to riding. The aim of this study was therefore to assess symmetry of posture, strength and flexibility in a large population of riders and to determine whether typical traits exist due to riding. 127 right handed riders from the UK and USA were categorized according to years riding (in 20 year increments and their competition level (using affiliated test levels. Leg length, grip strength and spinal posture were measured and recorded by a physiotherapist. Standing and sitting posture and trunk flexibility were measured with 3-D motion capture technology. Right-left differences were explored in relation to years riding and rider competitive experience. Significant anatomical asymmetry was found for the difference in standing acromion process height for a competition level (-0.07±1.50 cm Intro/Prelim; 0.02±1.31 cm Novice; 0.43±1.27 cm Elementary+; p=0.048 and for sitting iliac crest height for years riding (-0.23±1.36 cm Intro/Prelim; 0.01±1.50 cm Novice; 0.86±0.41 cm Elementary+; p=0.021. For functional asymmetry, a significant interaction was found for lateral bending ROM for years riding x competition level (p=0.047. The demands on dressage riders competing at higher levels may predispose these riders to a higher risk of developing asymmetry and potentially chronic back pain rather than improving their symmetry
Isen, Joshua; McGue, Matt; Iacono, William
Enhanced physical strength is a secondary sex characteristic in males. Sexual dimorphism in physical strength far exceeds sex differences in stature or total body mass, suggesting a legacy of intense sexual selection. Upper-body strength is a particularly promising marker of intrasexual competitiveness in young men. Consequently, it is assumed that sex-influenced gene expression contributes to the development of physical strength. It is unclear, however, whether the underlying sources of individual differences in strength development are comparable across sex. We obtained three measurements of hand-grip strength (HGS) over a six-year period spanning adolescence in male and female same-sex twins (N = 2,513). Biometrical latent growth models were used to partition the HGS variance at age 11 (intercept) and its growth over time (slope) into genetic and environmental components. Results demonstrated that variance around the intercept was highly heritable in both males and females (88% and 79%, respectively). In males, variance around the slope exceeded that of the intercept, while the reverse held for females. Additive genetic effects accounted for most (80%) of the variance around the slope in males, but were of less importance in females (heritability = 28%). Absolute genetic variance around the slope was nearly nine-fold higher in males. This striking disparity suggests that the developmental processes shaping HGS growth are different between the sexes. We propose that this might account for the sex-specific pattern of associations between HGS and external measures (e.g., digit ratio and physical aggression) typically reported in the literature. Our results underscore the role of endogenous androgenic influences in the development of physical strength.
Hobbs, Sarah Jane; Baxter, Joanna; Broom, Louise; Rossell, Laura-Ann; Sinclair, Jonathan; Clayton, Hilary M
Since the ability to train the horse to be ambidextrous is considered highly desirable, rider asymmetry is recognized as a negative trait. Acquired postural and functional asymmetry can originate from numerous anatomical regions, so it is difficult to suggest if any is developed due to riding. The aim of this study was therefore to assess symmetry of posture, strength and flexibility in a large population of riders and to determine whether typical traits exist due to riding. 127 right handed riders from the UK and USA were categorized according to years riding (in 20 year increments) and their competition level (using affiliated test levels). Leg length, grip strength and spinal posture were measured and recorded by a physiotherapist. Standing and sitting posture and trunk flexibility were measured with 3-D motion capture technology. Right-left differences were explored in relation to years riding and rider competitive experience. Significant anatomical asymmetry was found for the difference in standing acromion process height for a competition level (-0.07±1.50 cm Intro/Prelim; 0.02±1.31 cm Novice; 0.43±1.27 cm Elementary+; p=0.048) and for sitting iliac crest height for years riding (-0.23±1.36 cm Intro/Prelim; 0.01±1.50 cm Novice; 0.86±0.41 cm Elementary+; p=0.021). For functional asymmetry, a significant interaction was found for lateral bending ROM for years riding x competition level (p=0.047). The demands on dressage riders competing at higher levels may predispose these riders to a higher risk of developing asymmetry and potentially chronic back pain rather than improving their symmetry.
Jen van Horen
Full Text Available Taking control over work related stress. Mindfulness destresses social workersStress is a major social problem. Due to the increasing workload and the content of the work, social workers are at risk to develop stress (symptoms. The physical and psychological consequences of prolonged stress are serious. By living healthy, optimize working conditions and applying mindfulness, stress can be reduced. Mindfulness is an effective and useful way to reduce stress. It increases the resistance of workers against stress, improves brainfunctions and therefore has a positive effect on the performance. These effects are great, but they are still weakly methodologically substantiated. A pilot project within the youthcare though, was enthusiastically received and proves to be effective against stress symptoms. The exercises that are part of this pilot fit well with the needs of employees. For organizations mindfulnesstrainings are a time-and cost-effective way of structural stress prevention.Grip op werkstress. Mindfulness ontstresst maatschappelijk werkersStress is een omvangrijk maatschappelijk probleem. Door de toenemende werkdruk en de inhoud van het werk zijn maatschappelijk werkers een risicogroep om stress en stressklachten te ontwikkelen. De fysieke en psychische gevolgen die langdurige stress met zich meebrengt zijn ernstig. Door gezond te leven, de arbeidsomstandigheden te optimaliseren en mindfulness toe te passen kan stress terug worden gedrongen. Mindfulness is een effectieve en bruikbare manier om stress te verminderen. Het vergroot de weerbaarheid van werknemers tegen stress, het verbetert de hersenwerking en heeft daardoor een positief effect op het functioneren. Grote effecten dus, maar wel nog methodologisch zwak onderbouwd. Een pilot binnen de jeugdzorg op het gebied van mindfulness is enthousiast ontvangen en blijkt effectief tegen stressklachten. De oefeningen die onderdeel uitmaken van deze pilot sluiten goed aan bij de behoeften van
Pollard, Jonisha; Porter, William; Mayton, Alan; Xu, Xueyan; Weston, Eric
Falls from mobile equipment are reported at surface mine quarry operations each year in considerable numbers. Research shows that a preponderance of falls occur while getting on/off mobile equipment. Contributing factors to the risk of falls include the usage of ladders, exiting onto a slippery surface, and foot or hand slippage. Balance issues may also contribute to fall risks for mobile equipment operators who are exposed to whole-body vibration (WBV). For this reason, the National Institute for Occupational Safety and Health, Office of Mine Safety and Health Research conducted a study at four participating mine sites with seven haul truck operators. The purpose was to ascertain whether WBV and hand-arm vibration (HAV) exposures for quarry haul truck operators were linked to short-term decreases in performance in relation to postural stability, touch sensation threshold, and grip strength that are of crucial importance when getting on/off the trucks. WBV measures of frequency-weighted RMS accelerations (wRMS) and vibration dose value (VDV), when compared to the ISO/ANSI standards, were mostly below levels identified for the Health Guidance Caution Zone (HGCZ), although there were instances where the levels were within and above the specified Exposure Action Value. Comparably, all mean HAV levels, when compared to the ISO/ANSI standards, were below the HGCZ. For the existing conditions and equipment, no significant correlation could be identified between the WBV, HAV, postural stability, touch sensation threshold, and grip strength measures taken during this study.
de la Llave-Rincón, Ana Isabel; Fernández-de-Las-Peñas, César; Pérez-de-Heredia-Torres, Marta; Martínez-Perez, Almudena; Valenza, Marie Carmen; Pareja, Juan A
: The aim of this study was to analyze the differences in deficits in fine motor control and pinch grip force between patients with minimal, moderate/mild, or severe carpal tunnel syndrome (CTS) and healthy age- and hand dominance-matched controls. : A case-control study was conducted. The subtests of the Purdue Pegboard Test (one-hand and bilateral pin placements and assemblies) and pinch grip force between the thumb and the remaining four fingers of the hand were bilaterally evaluated in 66 women with minimal (n = 16), moderate (n = 16), or severe (n = 34) CTS and in 20 age- and hand-matched healthy women. The differences among the groups were analyzed using different mixed models of analysis of variance. : A two-way mixed analysis of variance revealed significant differences between groups, not depending on the presence of unilateral or bilateral symptoms (side), for the one-hand pin placement subtest: patients showed bilateral lower scores compared with controls (P < 0.001), without differences among those with minimal, moderate, or severe CTS (P = 0.946). The patients also exhibited lower scores in bilateral pin placement (P < 0.001) and assembly (P < 0.001) subtests, without differences among them. The three-way analysis of variance revealed significant differences among groups (P < 0.001) and fingers (P < 0.001), not depending on the presence of unilateral/bilateral symptoms (P = 0.684), for pinch grip force: patients showed bilateral lower pinch grip force in all fingers compared with healthy controls, without differences among those with minimal, moderate, or severe CTS. : The current study revealed similar bilateral deficits in fine motor control and pinch grip force in patients with minimal, moderate, or severe CTS, supporting that fine motor control deficits are a common feature of CTS not associated with electrodiagnostic findings.
A.R. Schreuders (Ton); M.E. Roebroeck (Marij); J.B. Jaquet (Jean); S.E.R. Hovius (Steven); H.J. Stam (Henk)
textabstractObjective: To compare the outcome of muscle strength with manual muscle strength testing grip and pinch strength measurements and a dynamometer which allows for measurements of the intrinsic muscles of the hand in isolation (the Rotterdam Intrinsic Hand Myometer, RIHM). Methods:
A.R. Schreuders (Ton); M.E. Roebroeck (Marij); J.B. Jaquet (Jean); S.E.R. Hovius (Steven); H.J. Stam (Henk)
textabstractObjective: To compare the outcome of muscle strength with manual muscle strength testing grip and pinch strength measurements and a dynamometer which allows for measurements of the intrinsic muscles of the hand in isolation (the Rotterdam Intrinsic Hand Myometer, RIHM). Methods: Thirty-f
van der Niet, Olga; Bongers, Raoul M.; van der Sluis, Corry K.
The availability of various multiarticulated prosthetic hands makes determining differences in functionality between these hands relevant. The current study asked whether the functionality of these hands increased with time of use and whether grip force and robustness improved. A 45-year-old man wit
Kamishima, Tamotsu; Terae, Satoshi [Hokkaido University Hospital, Department of Radiology, Sapporo (Japan); Tanimura, Kazuhide; Shimizu, Masato; Matsuhashi, Megumi; Fukae, Jun; Hagiwara, Hiromi; Narita, Akihiro; Aoki, Yuko [Hokkaido Medical Center for Rheumatic Diseases, Sapporo (Japan); Kon, Yujiro [St Thomas' Hospital, London (United Kingdom); Kosaka, Naoki [Tokeidai Memorial Hospital, Sapporo (Japan); Atsumi, Tatsuya [Hokkaido University Graduate School of Medicine, Department of Medicine, Sapporo (Japan); Shirato, Hiroki [Hokkaido University Graduate School of Medicine, Department of Radiology, Sapporo (Japan)
To compare quantitative magnetic resonance imaging (MRI) and power Doppler ultrasonography (PDUS) with conventional measures of disease activity in rheumatoid arthritis (RA) patients treated with the anti-interleukin 6 (anti-IL 6) receptor antibody tocilizumab in terms of responsiveness at a few months to disease activity and ability to predict structural damage at 1 year. A cohort of patients with RA (n = 29) was evaluated clinically including disease activity score 28 (DAS28) and by semiquantitative (SQ-) and quantitative (Q-) PDUS (bilateral metacarpophalangeal joints) and MRI (one hand and wrist) at initiation of treatment with anti-IL 6 receptor antibody agents and after 2 and 5 months. Conventional radiography for both hands and wrists was performed at baseline and at 12 months. Responsiveness was assessed by standardized response means (SRM). Areas under the curve (AUC) for measures at baseline, 2 and 5 months were correlated with structural damage at 1 year. Among the laboratory and clinical parameters, DAS28-ESR was the most responsive with a large effect size of SRM. Structural damage progressions for radiography and MR erosion were correlated with AUC of MR bone erosion and Q-PDUS, respectively. In the evaluation of disease activity in RA patients in the first few months after starting anti-IL 6 receptor antibody tocilizumab treatment, the semiquantitative MR bone erosion score of the hand and quantitative value for power Doppler signal in the finger joint were both responsive and predictive of structural damage progression at 1 year. (orig.)
Rosa, Elena V., E-mail: firstname.lastname@example.org; Ríos, Luis, E-mail: email@example.com
Highlights: •The gripping tool is based on only one gripping point centred at the plug bottom. •The gripping tool should allow the relative displacement in the gripping point to absorb the misalignment between plug and tractor. •The gripping tool needs to withstand around 100/30 kN during the plug extraction/insertion. •The gripping tool should rely on visual control and it has to avoid force feed-back. •The comparison between the features of several gripping tool concepts is assessed. -- Abstract: The conceptual design of several gripping tools and their mechanical interfaces is being carried out for the ITER ECH UPP within the WP10-GOTRH programme. EFDA finances the GOT RH (Goal Oriented Training Programme for Remote Handling). The purpose of this paper is to introduce new concepts of gripping tools for the plug extraction/insertion in the upper port of ITER. All these gripping tools are designed according to IO input data and geometrical constraints. The gripping tools have to be able to extract/insert the plug in the scenario of maximum misalignment between the plug and the tractor. The paper also defines the functional requirements the gripping tools need to comply with. The requirements and input data are verified and validated through 3D simulation with Catia mock-ups of the gripping tools. The strengths and weaknesses of each gripping tool model are compared.
Full Text Available Abstract Background If the model of the human hand is created with accuracy by respecting the type of motion provided by each articulation and the dimensions of articulated bones, it can function as the real organ providing the same motions. Unfortunately, the human hand is hard to model due to its kinematical chains submitted to motion constraints. On the other hand, if an application does not impose a fine manipulation it is not necessary to create a model as complex as the human hand is. But always the hand model has to perform a certain space of motions in imposed workspace architecture no matter what the practical application does. Methods Based on Denavit-Hartenberg convention, we conceived the kinematical model of the human hand, having in mind the structure and the behavior of the natural model. We obtained the kinematical equations describing the motion of every fingertip with respect to the general coordinate system, placed on the wrist. For every joint variable, a range of motion was established. Dividing these joint variables to an appropriate number of intervals and connecting them, the complex surface bordering the active hand model workspace was obtained. Results Using MATLAB 7.0, the complex surface described by fingertips, when hand articulations are all simultaneously moving, was obtained. It can be seen that any point on surface has its own coordinates smaller than the maximum length of the middle finger in static position. Therefore, a sphere having the centre in the origin of the general coordinate system and the radius which equals this length covers the represented complex surface. Conclusion We propose a human hand model that represents a new solution compared to the existing ones. This model is capable to make special movements like power grip and dexterous manipulations. During them, the fingertips do not exceed the active workspace encapsulated by determined surfaces. The proposed kinematical model can help to choose
Full Text Available GRIPS is a proposed gamma-ray (200 keV to 80 MeV astronomy mission, which incorporates a pair-creation and Compton scattering telescope, along with X-ray and infrared telescopes. It will carry out a sensitive all-sky scanning survey, investigating phenomena such as gamma-ray bursts, blazars and core collapse supernovae. The main telescope is composed of a Si strip detector surroundedby a calorimeter with a fast scintillator material. We present the initial results of a study which considers the potential use of silicon photomultipliers in conjunction with the scintillator in the GRIPS calorimeter module.
... Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is a Hand Surgeon? What is a Hand Therapist? Media Find a Hand Surgeon Home Anatomy Bones Joints Muscles Nerves Vessels Tendons Anatomy The upper extremity is ...
Vlachos, Evgenios; Schärfe, Henrik
. On such occasions, android and humanoid hand models should have similar structure, functions, and performance as the human hand. In this paper we present the anatomy, and the key functionalities of the human hand followed by a literature review on android/humanoid hands for grasping and manipulating objects...
The wide use of the coefficient of variation in detecting sincerity of effort is puzzling since existing research findings regarding its effectiveness are contradictory. The lack of empirical support in the literature raises the question of whether or not the coefficient of variation is a valid measure for detecting sincerity of effort. Many clinicians, especially those who use a computer software to calculate the coefficient of variation, may not understand how the coefficient of variation is derived and what it is based on. The coefficient of variation is a measure of relative variability and would be used correctly only if the average and the standard deviation of grip strength trials increased proportionally. This case study, however, demonstrated that the average and standard deviation of grip strength are independent. Thus, the coefficient of variation is not a valid measure of sincerity of effort. In addition, this study indicated that the coefficient of variation may be inflated in individuals after carpal tunnel release surgery. The author, therefore, cautions clinicians against the use of the coefficient of variation as a measure of sincerity of effort especially in injured individuals with compromised hand strength.
Wilmut, Kate; Byrne, Maia
When generating a movement adults favor grasps which start the body in an uncomfortable position if they end in a comfortable position (the end-state-comfort effect). In contrast, children with Developmental Coordination Disorder (DCD) select grasps which require little initial hand rotation even though they result in an uncomfortable end position. The current study considered grip selection of individuals with DCD when asked to make simple one step movements and when making more complex multi-staged movements. Adults with DCD (N=17, mean age 24:09, SD age=52months) and children with DCD (N=20, mean age 9:00, SD age=20months) and age and gender matched controls rotated a disc so an arrow pointed toward a specific target(s). Task complexity was increased by increasing the number of targets from 1 to 3. Planning for end-state-comfort was seen in all groups albeit to a lesser extent in children versus adults. The children with DCD showed fewer grips for end-state-comfort compared to their peers and this was explained by a propensity to select minimal initial rotation grasps. This result was mirrored in adults with DCD but only for the longest movement sequence. These results suggest some changes in ability from childhood to adulthood in individuals with DCD.
Eidenmüller, S; Randerath, J; Goldenberg, G; Li, Y; Hermsdörfer, J
The scaling of our finger forces according to the properties of manipulated objects is an elementary prerequisite of skilled motor behavior. Lesions of the motor-dominant left brain may impair several aspects of motor planning. For example, limb-apraxia, a tool-use disorder after left brain damage is thought to be caused by deficient recall or integration of tool-use knowledge into an action plan. The aim of the present study was to investigate whether left brain damage affects anticipatory force scaling when lifting everyday objects. We examined 26 stroke patients with unilateral brain damage (16 with left brain damage, ten with right brain damage) and 21 healthy control subjects. Limb apraxia was assessed by testing pantomime of familiar tool-use and imitation of meaningless hand postures. Participants grasped and lifted twelve randomly presented everyday objects. Grip force was measured with help of sensors fixed on thumb, index and middle-finger. The maximum rate of grip force was determined to quantify the precision of anticipation of object properties. Regression analysis yielded clear deficits of anticipation in the group of patients with left brain damage, while the comparison of patient with right brain damage with their respective control group did not reveal comparable deficits. Lesion-analyses indicate that brain structures typically associated with a tool-use network in the left hemisphere play an essential role for anticipatory grip force scaling, especially the left inferior frontal gyrus (IFG) and the premotor cortex (PMC). Furthermore, significant correlations of impaired anticipation with limb apraxia scores suggest shared representations. However, the presence of dissociations, implicates also independent processes. Overall, our findings suggest that the left hemisphere is engaged in anticipatory grip force scaling for lifting everyday objects. The underlying neural substrate is not restricted to a single region or stream; instead it may rely on
Liss, Frederic E
The interosseous muscles of the hand can be thought of as the cornerstone of hand function, as they provide a "foundation" for all intrinsic and extrinsic hand movements. Innervated by the ulnar nerve and organized in dorsal and palmar layers, these pivotal muscles have small excursion yet great impact on finger balance, grip, and pinch function, particularly when impaired by denervation and/or contracture. This article gives an overview of the functional anatomy and pathologic dysfunction of the interosseous muscles within the context of this Hand Clinics issue on the intrinsic muscular function of the hand. Copyright © 2012 Elsevier Inc. All rights reserved.
That movies are a great source of entertainment seems to be common sense. But how exactly movies manage to get large audiences absorbed, or what is their gripping tool is still a mystery. Research makes use of different concepts pointing to narrative absorption, but it is not clear how they differ f
Mikkelsen, Lone Ramer; Mechlenburg, Inger; Petersen, Annemette Krintel
INTRODUCTION: Rehabilitation has an increasing focus on intensive resistance training early after joint replacement (1,2). This increases the requests for measuring changes in the muscle strength and muscle power over time. Hand-held dynamometer (HHD) is a device used to measure isometric muscle...... strength and Leg Extensor Power Rig (LEPR) is a tool for measuring muscle power. OBJECTIVES: To test the inter-tester reliability of the HHD in hip abduction and the LEPR in Total Hip Arthroplasty (THA) patients. METHODS: Two groups each consisting 20 subjects were included. Mean age was 68.4 years. All...... the two testers (p=0.62) and the two tests (0.14); ICC=0.91 (95% CI: 0.79;0.96); LOA=±34Watt. CONCLUSION: The relative reliability was acceptable for both HHD and LEPR. The absolute reliability showed that a change in the muscle strength/power above 18 Newton or 34 Watt can be counted as a real change...
Mikkelsen, Lone Ramer; Petersen, Annemette Krintel; Mikkelsen, Søren Søndergaard
Background: Rehabilitation has an increasing focus on intensive resistance training early after joint replacement. This increases the requests for measuring changes in the muscle strength and muscle power over time. Hand-held dynamometer (HHD) is a device used to measure isometric muscle strength...... and Leg Extensor Power Rig (LEPR) is a tool for measuring muscle power. Purpose / Aim of Study: To test the inter-tester reliability of the HHD and the LEPR in Total Hip Arthroplasty (THA) patients. Materials and Methods: Two groups each consisting 20 subjects were included. Mean age was 68.4 years. All...... between the two testers (p=0.62) and the two tests (0.14); ICC=0.91 (95% CI: 0.79;0.96); LOA=±34Watt. Conclusions: The relative reliability was acceptable for both HHD and LEPR. The absolute reliability showed that a change in the muscle strength/power above 18 Newton or 34 Watt can be counted as a real...
Full Text Available The construct of sarcopenia is still discussed with regard to best appropriate measures of muscle volume and muscle function. The aim of this post-hoc analysis of a cross-sectional experimental study was to investigate and describe the hierarchy of the association between thigh muscle volume and measurements of functional performance in older women. Thigh muscle volume of 68 independently living older women (mean age 77.6 years was measured via magnetic resonance imaging. Isometric strength was assessed for leg extension in a movement laboratory in sitting position with the knee flexed at 90° and for hand grip. Maximum and habitual gait speed was measured on an electronic walk way. Leg muscle power was measured during single leg push and during sit-to-stand performance. Thigh muscle volume was associated with sit-to-stand performance power (r = 0.628, leg push power (r = 0.550, isometric quadriceps strength (r = 0.442, hand grip strength (r = 0.367, fast gait speed (r = 0.291, habitual gait speed (r = 0.256, body mass index (r = 0.411 and age (r = -0.392. Muscle power showed the highest association with thigh muscle volume in healthy older women. Sit-to-stand performance power showed an even higher association with thigh muscle volume compared to single leg push power.
Lindemann, Ulrich; Mohr, Christian; Machann, Juergen; Blatzonis, Konstantinos; Rapp, Kilian; Becker, Clemens
The construct of sarcopenia is still discussed with regard to best appropriate measures of muscle volume and muscle function. The aim of this post-hoc analysis of a cross-sectional experimental study was to investigate and describe the hierarchy of the association between thigh muscle volume and measurements of functional performance in older women. Thigh muscle volume of 68 independently living older women (mean age 77.6 years) was measured via magnetic resonance imaging. Isometric strength was assessed for leg extension in a movement laboratory in sitting position with the knee flexed at 90° and for hand grip. Maximum and habitual gait speed was measured on an electronic walk way. Leg muscle power was measured during single leg push and during sit-to-stand performance. Thigh muscle volume was associated with sit-to-stand performance power (r = 0.628), leg push power (r = 0.550), isometric quadriceps strength (r = 0.442), hand grip strength (r = 0.367), fast gait speed (r = 0.291), habitual gait speed (r = 0.256), body mass index (r = 0.411) and age (r = -0.392). Muscle power showed the highest association with thigh muscle volume in healthy older women. Sit-to-stand performance power showed an even higher association with thigh muscle volume compared to single leg push power.
Li, Ke; Hogrel, Jean-Yves; Duchêne, Jacques; Hewson, David J
The objective of this study was to evaluate muscle fatigue and tremor during a Sustained Maximal Grip Contraction (SMGC) using the Hilbert-Huang Transformation (HHT). Thirty-nine healthy subjects volunteered for the study and performed a 25-s SMGC. Fatigue parameters such as the relative force output (RFO) were calculated from the residual of SMGC after applying Empirical Mode Decomposition (EMD). Using the energy spectrum of the Intrinsic Mode Functions (IMF) obtained using HHT, isometric force tremor was identified from the 4 to 12 Hz region in IMF3 and IMF4. Data were analysed for five consecutive 5-s epochs to identify changes in fatigue and tremor over time. The HHT method was able to identify a greater resistance to fatigue in women compared to men (p≤0.05) and in non-dominant hands compared to dominant hands (p≤0.05). Consistent with the results for fatigue, women had less tremor than men (p≤0.05), while non-dominant hands trembled less than did dominant hands (p≤0.05). Higher levels of tremor were observed for non-fatigue-resistant subjects for both 10-15 s and 15-20 s epochs (p≤0.05). The HHT is an appropriate method to identify both fatigue and tremor during SMGC. It would be of interest to apply this method to the study the elderly or patients with neuromuscular disorders.
Many clinicians use the coefficient of variation (CV) to assess sincerity of effort, without understanding the premise on which it is based or its physiological and mathematical bases. Clinicians who use computerized evaluation systems that calculate the CV may not even be aware of the formula used to derive it. The wide use of the CV in detecting sincerity of effort of grip strength is puzzling, since it lacks empirical support in the literature. This paper examines the physiological rationale for using measures of variability to detect sincerity of effort, the mathematical basis on which the CV is founded, and the reliability and validity of the CV. The conclusions based on this literature review are that the CV is not an appropriate method for determining whether an effort is sincere and that CV values may be inflated in injured patients with compromised hand strength.
ZHAO Jing-dong; JIANG Li; CAI He-gao; LIU hong
A five-fingered underactuated prosthetic hand controlled by surface EMG (electromyographic) sig-nals is presented in this paper. The prosthetic hand was designed with simplicity, lightweight and dexterity on the requirement of anthropomorphic hands. Underactuated self-adaptive theory was adopted to decrease the number of motors and weight. The control part of the prosthetic hand was based on a surface EMG motion pat-tern classifier which combines LM-based (Levenberg-Marquardt) neural network with the parametric AR ( au-toregressive) model. This motion pattern classifier can successfully identify the flexions of the thumb, the index finger and the middle finger by measuring the surface EMG signals through two electrodes mounted on the flexor digitorum profundus and flexor pollicis longus. Furthermore, via continuously controlling a single finger' s mo-tion, the five-fingered underactuated prosthetic hand can achieve more prehensile postures such as power grasp,centralized grip, fingertip grasp, cylindrical grasp, etc. The experimental results show that the classifier has a great potential application to the control of bionic man-machine systems because of its fast learning speed, high recognition capability and strong robustness.
... Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is a Hand Surgeon? What is ... serve as a framework. This framework supports the muscles that make the wrist ... When one of these hand bones is broken (fractured), it can prevent you ...
Shechtman, O; Taylor, C
The rapid exchange grip (REG) test was developed to identify patients exerting insincere effort. The premise of the REG test is that a maximal, sincere effort yields a "negative REG," in which peak static grip (SG) scores are greater than peak REG scores, and that a submaximal, insincere effort yields a "positive REG," in which REG scores are greater than SG scores. There is disagreement in the literature concerning what constitutes a positive REG test, suggesting that the REG may not be a valid measure of sincerity of effort. The purpose of the present study was to investigate the validity of the REG test by examining its premise as well as its sensitivity and specificity values. The 146 uninjured subjects performed a series of randomized grip strength tests, exerting both maximal and submaximal efforts. The tests included the REG at hand switch rates of 45 rpm (REG-45) and 60 rpm (REG-60), the maximal static grip test (MSGT), and the five-rung test (5R). Our findings supported the concept of a "negative REG" for both REG maneuvers and both comparative SG tests. The concept of a "positive REG," however, was supported only when peak REG scores were compared with peak 5R scores. The authors found relatively low sensitivity and specificity values, suggesting that the REG test may not be sensitive or specific enough to effectively detect sincerity of effort. The authors discuss the likelihood that mistakes will be made when the REG test is used to diagnose sincerity of effort and the possible consequences of making such mistakes.
Full Text Available Brain lesions may disturb hand functioning in children with cerebral palsy (CP, making it difficult or even impossible for them to perform several manual activities. Most conventional treatments for hand dysfunction in CP assume that reducing the hand dysfunctions will improve the capacity to manage activities (i.e., manual ability, MA. The aim of this study was to investigate the directional relationships (direct and indirect pathways through which hand skills influence MA in children with CP. A total of 136 children with CP (mean age: 10 years; range: 6–16 years; 35 quadriplegics, 24 diplegics, 77 hemiplegics were assessed. Six hand skills were measured on both hands: touch-pressure detection (Semmes-Weinstein aesthesiometer, stereognosis (Manual Form Perception Test, proprioception (passive mobilization of the metacarpophalangeal joints, grip strength (Jamar dynamometer, gross manual dexterity (Box and Block Test, and fine finger dexterity (Purdue Pegboard Test. MA was measured with the ABILHAND-Kids questionnaire. Correlation coefficients were used to determine the linear associations between observed variables. A path analysis of structural equation modeling was applied to test different models of causal relationships among the observed variables. Purely sensory impairments did seem not to play a significant role in the capacity to perform manual activities. According to path analysis, gross manual dexterity in both hands and stereognosis in the dominant hand were directly related to MA, whereas grip strength was indirectly related to MA through its relationship with gross manual dexterity. However, one-third of the variance in MA measures could not be explained by hand skills. It can be concluded that MA is not simply the integration of hand skills in daily activities and should be treated per se, supporting activity-based interventions.
Full Text Available The paper discusses the position of young people in Serbia today, as can be inferred from the evidence collected in the study "Politics and everyday life - three years later". Starting from the typology she developed in her 2002 analysis of young people’s interviews (when four basic ways of self-positioning within the social context were identified: "B92 generation", "provincials", "fundamentalists", and "guests", the author traces the changes that have intervened over the past three years in the attitudes of these same respondents concerning politics, personal engagement, views of the future and of their own selves. The fact that the expectations, awakened by the events of 5 October 2000, have been betrayed, has brought strong disappointment, and it is the context in which young people in Serbia once again are losing faith that they will ever find their place in their own society. Against the background of a basic tension in relation to politics - between excessive interest and disgust - there basic strategies of young people in 2005 are formed. "Withdrawal", as the most common strategy, indicates a return of the young to their narrow personal, private, imaginary world, after a short exit into reality and active participation in creating the conditions of their own social existence. The increasingly frequent strategy of "aggression and imposition of one’s own worldview" points to the rising radicalization of the young generation. Finally, it is only the "planning strategy", espoused by just a handful of respondents, that retains traces of faith in future improvement of social conditions.
Winges, Sara A.; Santello, Marco
SYNOPSIS This paper is a mini review of kinetic and kinematic evidence on the control of the hand with emphasis on grasping. It is not meant to be an exhaustive review, rather it summarizes current research examining the mechanisms through which specific patterns of coordination are elicited and observed during reach to grasp movements and static grasping. These coordination patterns include the spatial and temporal covariation of the rotation at multiple joints during reach to grasp movements. A basic coordination between grip forces produced by multiple digits also occurs during whole hand grasping such that normal forces tend to be produced in a synchronous fashion across pairs of digits. Finally, we address current research that suggests that motor unit synchrony across hand muscles and muscle compartments might be one of the neural mechanisms underlying the control of grasping. PMID:18414593
Huang, Sheau-Ling; Hsieh, Ching-Lin; Lin, Jau-Hong; Chen, Hui-Mei
The purpose of this study was to determine the optimal scoring methods for measuring strength of the more-affected hand in patients with stroke by examining the effect of reducing measurement errors. Three hand-strength tests of grip, palmar pinch, and lateral pinch were administered at two sessions in 56 patients with stroke. Five scoring methods…
This paper hans three interrelated parts. First, atmosphere is approached through the concept of power. Atmospheres 'grip' us directly or mediate power indirectly by manipulating moods and evoking emotions. How does atmosphere relate to different conceptions of power? Second, atmospheric powers m...... be critiqued. Which conception of critique can be involved? Third, critiquing atmospheric powers can generate political conflict. How does atmospheric disputes relate to conceptions of politics and the political?...
Short-Term Effects of Whole-Body Vibration Combined with Task-Related Training on Upper Extremity Function, Spasticity, and Grip Strength in Subjects with Poststroke Hemiplegia: A Pilot Randomized Controlled Trial.
Lee, Jung-Sun; Kim, Chang-Yong; Kim, Hyeong-Dong
The aim of this study was to determine the effect of whole-body vibration training combined with task-related training on arm function, spasticity, and grip strength in subjects with poststroke hemiplegia. Forty-five subjects with poststroke were randomly allocated to 3 groups, each with 15 subjects as follows: control group, whole-body vibration group, and whole-body vibration plus task-related training group. Outcome was evaluated by clinical evaluation and measurements of the grip strength before and 4 weeks after intervention. Our results show that there was a significantly greater increase in the Fugl-Meyer scale, maximal grip strength of the affected hand, and grip strength normalized to the less affected hand in subjects undergoing the whole-body vibration training compared with the control group after the test. Furthermore, there was a significantly greater increase in the Wolf motor function test and a decrease in the modified Ashworth spasticity total scores in subjects who underwent whole-body vibration plus task-related training compared with those in the other 2 groups after the test. The findings indicate that the use of whole-body vibration training combined with task-related training has more benefits on the improvement of arm function, spasticity, and maximal grip strength than conventional upper limb training alone or with whole-body vibration in people with poststroke hemiplegia.
Greiner, J; Aharonian, F; Ajello, M; Balasz, L G; Barbiellini, G; Bellazzini, R; Bishop, S; Bisnovatij-Kogan, G S; Boggs, S; Bykov, A; DiCocco, G; Diehl, R; Elsässer, D; Foley, S; Fransson, C; Gehrels, N; Hanlon, L; Hartmann, D; Hermsen, W; Hillebrandt, W; Hudec, R; Iyudin, A; Jose, J; Kadler, M; Kanbach, G; Klamra, W; Kiener, J; Klose, S; Kreykenbohm, I; Kuiper, L M; Kylafis, N; Labanti, C; Langanke, K; Langer, N; Larsson, S; Leibundgut, B; Laux, U; Longo, F; Maeda, K; Marcinkowski, R; Marisaldi, M; McBreen, B; McBreen, S; Meszaros, A; Nomoto, K; Pearce, M; Peer, A; Pian, E; Prantzos, N; Raffelt, G; Reimer, O; Rhode, W; Ryde, F; Schmidt, C; Silk, J; Shustov, B M; Strong, A; Tanvir, N; Thielemann, F -K; Tibolla, O; Tierney, D; Trümper, J; Varshalovich, D A; Wilms, J; Wrochna, G; Zdziarski, A; Zoglauer, A
We propose to perform a continuously scanning all-sky survey from 200 keV to 80 MeV achieving a sensitivity which is better by a factor of 40 or more compared to the previous missions in this energy range. The Gamma-Ray Imaging, Polarimetry and Spectroscopy (GRIPS) mission addresses fundamental questions in ESA's Cosmic Vision plan. Among the major themes of the strategic plan, GRIPS has its focus on the evolving, violent Universe, exploring a unique energy window. We propose to investigate $\\gamma$-ray bursts and blazars, the mechanisms behind supernova explosions, nucleosynthesis and spallation, the enigmatic origin of positrons in our Galaxy, and the nature of radiation processes and particle acceleration in extreme cosmic sources including pulsars and magnetars. The natural energy scale for these non-thermal processes is of the order of MeV. Although they can be partially and indirectly studied using other methods, only the proposed GRIPS measurements will provide direct access to their primary photons. G...
Andrade, Aaron; Hern, H Gene
At the start of your Saturday afternoon shift, you are not surprised to see that several patients are waiting to be seen for physical injuries. The first patient is a 34-year-old woman who sustained injury to her hand while skiing, 2 hours prior to her arrival. She reports falling with her hand still tethered to the pole's grip, landing on her outstretched right hand. She felt a painful snap in her right thumb, which still hurts, but otherwise she did not sustain any other trauma. Her only complaint currently is pain at the base of the right thumb. The patient is otherwise completely healthy, has no past medical or surgical history, and takes no medications. Upon examination, the affected hand appears to be surprisingly normal except for mild tenderness and swelling over the ulnar aspect of her first metacarpophalangeal joint and mildly decreased strength in her pincher grasp. X-ray reveals no fracture. You wonder if there is additional testing that should be done to evaluate this injury. You move on to a second patient, a 24-year-old man who cut his ring finger knuckle when he punched a wall 2 days ago. Physical examination reveals a small puncture wound over the IV metacarpophalangeal joint with mild swelling, erythema, warmth, and decreased range of motion secondary to pain. X-ray reveals no fracture, but there's something suspicious about this case. A third patient is a 37-year-old industrial worker whose finger contacted the stream of a high-powered grease injector. Physical examination reveals a small puncture wound over the volar proximal interphalangeal joint of his left long finger, mild tenderness to palpation over the area, and slight decreased range of motion secondary to pain. You wonder if the injury is as benign as it looks.
Lin, Jia-Hua; McGorry, Raymond W; Banks, Jacob J
Powered hand tools have the potential to produce reaction forces that may be associated with upper extremity musculoskeletal disorders. This study examined and compared the kinetic and physiological impacts on operator upper extremities between the fastening and unfastening operations. Thirty-two healthy, right-handed male operators used four tools on two joint simulators at different working heights and distances in the laboratory. Three work configurations were simulated: pistol grip tools on a vertical and horizontal surface, and right angle tools on a horizontal surface. Grip force was measured on an instrumented handle attached to each tool. Muscle activity was monitored at the wrist flexor and extensor and the upper trapezius of the right arm. Paired comparisons showed that when pistol grip tools were used, the peak torque to unfasten a joint (3.7 Nm) was significantly less than to fasten the same joint (5.7 Nm). However, the exposure time was longer for unfastening cycles (98 ms more on the horizontal surface, and 107 ms more on the vertical surface). The average grip force scaled to corresponding peak tool torque revealed that the effort to react against torque was greater in unfastening cycles than in fastening cycles for all work configurations. It also showed that as a proximal stabilizer, the upper trapezius muscle had a greater activity in unfastening cycles. The kinetic and physiological responses demonstrated that unfastening fasteners, which has been neglected in the literature, have the potential to increase risk for musculoskeletal disorders and should be considered in ergonomics assessment in the workplace.
A 33-year-old woman presents with redness of the hands and reports the intermittent occurrence of tiny vesicles, scaling, and fissuring, accompanied by itching on the palms, fingers, and dorsal sides of the hands. She has two young children and works as a nurse in a nearby hospital. She has a histor
New Kadima leader Tzipi Livni seeks coalition partners as the Israeli-Palestinian peace process continues on September 17, Israeli Foreign Minister Tzipi Livni narrowly won a leadership contest in the
Domalain, M; Vigouroux, L; Danion, F; Sevrez, V; Berton, E
This study aimed to define the effect of object width on spontaneous grasp. Participants held objects of various masses (0.75 to 2.25 kg) and widths (3.5 to 9.5 cm) between thumb and index finger. Grip force, maximal grip force and corresponding finger postures were recorded using an embedded force sensor and an optoelectronic system, respectively. Results showed that index finger joints varied to accommodate the object width, whereas thumb posture remained constant across conditions. For a given object mass, grip force increased as a function of object width, although this result is not dictated by the laws of mechanics. Because maximal grip force also increased with object width, we hypothesise that participants maintain a constant ratio between grip force and their maximal grip force at each given width. Altogether we conclude that when the task consists in manipulating objects/tools, the optimal width is different than when maximal force exertions are required.
Full Text Available In this paper, the authors presented a study on the discrimination of handlebar grip samples, to provide effective forensic science service for hit and run traffic cases. 50 bicycle handlebar grip samples, 49 electric bike handlebar grip samples, and 96 motorcycle handlebar grip samples have been randomly collected by the local police in Beijing (China. Fourier transform infrared microspectroscopy (FTIR was utilized as analytical technology. Then, target absorption selection, data pretreatment, and discrimination of linked samples and unlinked samples were chosen as three steps to improve the discrimination of FTIR spectrums collected from different handlebar grip samples. Principal component analysis and receiver operating characteristic curve were utilized to evaluate different data selection methods and different data pretreatment methods, respectively. It is possible to explore the evidential value of handlebar grip residue evidence through instrumental analysis and statistical treatments. It will provide a universal discrimination method for other forensic science samples as well.
Agarwal, Uma Shankar; Besarwal, Raj Kumar; Gupta, Rahul; Agarwal, Puneet; Napalia, Sheetal
Hand eczema is often a chronic, multifactorial disease. It is usually related to occupational or routine household activities. Exact etiology of the disease is difficult to determine. It may become severe enough and disabling to many of patients in course of time. An estimated 2-10% of population is likely to develop hand eczema at some point of time during life. It appears to be the most common occupational skin disease, comprising 9-35% of all occupational diseases and up to 80% or more of all occupational contact dermatitis. So, it becomes important to find the exact etiology and classification of the disease and to use the appropriate preventive and treatment measures. Despite its importance in the dermatological practice, very few Indian studies have been done till date to investigate the epidemiological trends, etiology, and treatment options for hand eczema. In this review, we tried to find the etiology, epidemiology, and available treatment modalities for chronic hand eczema patients.
Full Text Available This paper presents a theoretical investigation on the decrease in grip coefficient of a car due to the car mass changes for three different running conditions- straightforward, motion in curve and braking. The grip of two types of cars - with forward and rear traction, equipped with three models of tires are studied. The results show a significant decrease of the grip coefficient in longitudinal and lateral directions.
Crossley, F. R. E.
This paper describes the construction of a prototype mechanical hand or 'end effector' for use on a remotely controlled robot, but with possible application as a prosthetic device. An analysis of hand motions is reported, from which it is concluded that the two most important manipulations (apart from grasps) are to be able to pick up a tool and draw it into a nested grip against the palm, and to be able to hold a pistol-grip tool such as an electric drill and pull the trigger. One of our models was tested and found capable of both these operations.
Kasapoğlu Aksoy, Meliha; Altan, Lale; Eröksüz, Rıza; Metin Ökmen, Burcu
Hand osteoarthritis (OA) is associated with pain, reduced grip strength, loss of range of motion (ROM), and joint stiffness, leading to impaired hand function and difficulty in performance of daily living activities. Mud bath therapy has been reported to play a primary role in the prevention and management of OA. Thus, we planned to conduct a study aimed at investigating the effects of peloid therapy on pain, functional state, grip strength, and the quality of life and performing a comparative analysis of the outcomes of peloid therapy. In this randomized, controlled, single-blind, pilot study, patients (n = 33) underwent peloid therapy over 2 weeks, 5 sessions a week, for a total of 10 sessions and home exercise program in group 1. Patients in group 2 (control, n = 30) received only the same home exercise program as in group 1. Patients were evaluated just before, and 2 and 6 weeks after the start of the study with Visual Analogue Scale (VAS), Australian/Canadian Hand Osteoarthritis Index (AUSCAN), Health Assessment Questionnaire (HAQ), hand grip strength (HGS), and pinch strength (PS). Statistically significant improvements were observed in all parameters assessed at week 2 and week 6 in the group 1 (p management of symptomatic osteoarthritis of the hand and may provide effective pain control and improvements in the hand functions, quality of life, and grip strength.
Adams, Michael J.; Johnson, Simon A.; Lefèvre, Philippe; Lévesque, Vincent; Hayward, Vincent; André, Thibaut; Thonnard, Jean-Louis
Many aspects of both grip function and tactile perception depend on complex frictional interactions occurring in the contact zone of the finger pad, which is the subject of the current review. While it is well established that friction plays a crucial role in grip function, its exact contribution for discriminatory touch involving the sliding of a finger pad is more elusive. For texture discrimination, it is clear that vibrotaction plays an important role in the discriminatory mechanisms. Among other factors, friction impacts the nature of the vibrations generated by the relative movement of the fingertip skin against a probed object. Friction also has a major influence on the perceived tactile pleasantness of a surface. The contact mechanics of a finger pad is governed by the fingerprint ridges and the sweat that is exuded from pores located on these ridges. Counterintuitively, the coefficient of friction can increase by an order of magnitude in a period of tens of seconds when in contact with an impermeably smooth surface, such as glass. In contrast, the value will decrease for a porous surface, such as paper. The increase in friction is attributed to an occlusion mechanism and can be described by first-order kinetics. Surprisingly, the sensitivity of the coefficient of friction to the normal load and sliding velocity is comparatively of second order, yet these dependencies provide the main basis of theoretical models which, to-date, largely ignore the time evolution of the frictional dynamics. One well-known effect on taction is the possibility of inducing stick–slip if the friction decreases with increasing sliding velocity. Moreover, the initial slip of a finger pad occurs by the propagation of an annulus of failure from the perimeter of the contact zone and this phenomenon could be important in tactile perception and grip function. PMID:23256185
Yang, Hongmei; Kong, Qingkun; Wang, Shaowei; Xu, Jinmeng; Bian, Zhaoquan; Zheng, Xiaoxiao; Ma, Chao; Ge, Shenguang; Yu, Jinghua
In this paper, a pen-on-paper electrochemiluminescence (PoP-ECL) device was entirely hand drawn and written in commercially available crayon and pencil in turn for the first time, and a constant potential-triggered sandwich-type immunosensor was introduced into the PoP-ECL device to form a low-cost ECL immunodevice proof. Each PoP-ECL device contained a hydrophilic paper channel and two PoP electrodes, and the PoP-ECL device was produced as follows: crayon was firstly used to draw hydrophobic regions on pure cellulose paper to create the hydrophilic paper channels followed with a baking treatment, and then a 6B-type black pencil with low resistivity was applied for precision writing, as the PoP electrodes, across the hydrophilic paper channel. For further point-of-care testing, a portable, low-cost rechargeable battery was employed as the power source to provide constant potential to the PoP electrodes to trigger the ECL. Using Carbohydrate antigen 199 as model analyte, this PoP-ECL immunodevice showed a good linear response range from 0.01-200 U mL(-1) with a detection limit of 0.0055 U mL(-1), a high sensitivity and stability. The proposed PoP-ECL immunodevice could be used in point-of-care testing of other tumor markers for remote regions and developing countries. Copyright © 2014 Elsevier B.V. All rights reserved.
The primary scientific goal of the GRIPS mission is to revolutionize our understanding of the early universe using gamma-ray bursts. We propose a new generation gamma-ray observatory capable of unprecedented spectroscopy over a wide range of gamma-ray energies (200 keV--50 MeV) and of polarimetry (200--1000 keV). Secondary goals achievable by this mission include direct measurements of supernova interiors through gamma-rays from radioactive decays, nuclear astrophysics with massive stars and novae, and studies of particle acceleration near compact stars, interstellar shocks, and clusters of galaxies.
Fox, Benjamin; Henwood, Tim; Schaap, Laura; Bruyère, Olivier; Reginster, Jean-Yves; Beaudart, Charlotte; Buckinx, Fanny; Roberts, Helen; Cooper, Cyrus; Cherubini, Antonio; dellʼAquilla, Giuseppina; Maggio, Marcello; Volpato, Stefano
studies. On the other hand, within this definition there still is wide variability in measurement tools and use of cut-off values, which could actually hamper comparability between studies.To assess muscle strength, the EWGSOP has recommended grip strength measurement which is easy and inexpensive. A recent systematic review on the measurement properties of tools to assess sarcopenia concluded that grip strength measurement is a valid and reliable method. In a comprehensive review of the measurement of grip strength in clinical and epidemiological studies by Roberts et al., it was shown that there is wide variability in the choice of equipment and protocols for measuring grip strength. To enable comparison between studies, a standardized approach, incorporating more consistent measurement of grip strength is warranted. Based on the results of the review, a standardized approach was described including the utilization of the widely used Jamar hydraulic hand dynamometer, as was a clear assessment protocol. So far, it is unknown whether this approach has been adopted in studies investigating grip strength for sarcopenia. The primary aim of this current review is to identify whether studies are adhering to the suggested protocol, or whether a more common method is prevalent. The EWGSOP has suggested multiple cut-off values to define sarcopenia regarding muscle strength: an absolute cut-off score of 20 kilograms (kg) for women and 30 kg for men, and Body Mass Index (BMI) specific cut-off values for men and women. Alternatively, the Foundation for the National Institutes of Health (FNIH) Sarcopenia Study suggested cut-off points of 26kg for males and 16kg for females, based on the likelihood of mobility impairment. Similar values have also been suggested by Dodds et al., who generated grip strength reference values and calculated cut-off points 2.5 standard deviations below the mean from 12 United Kingdom (U.K)based epidemiology studies.Recently, Beaudart et al. showed that
Full Text Available List Contact us GRIPDB GRIP Database original data Data detail Data name GRIP Database original data DOI 10....18908/lsdba.nbdc01665-006 Description of data contents GRIP Database original data It consists of data table...s and sequences. Data file File name: gripdb_original_data.zip File URL: ftp://ftp.biosciencedbc.jp/archive/gripdb/LATEST/gripdb_orig...e Database Description Download License Update History of This Database Site Policy | Contact Us GRIP Database original data - GRIPDB | LSDB Archive ... ...inal_data.zip File size: 779 KB Simple search URL - Data
Koziatek, Susan M; Powell, Nancy J
The purpose of this research was to study how the speed and legibility of fourth-graders handwriting was affected by type of pencil grip on the Evaluation Tool of Children's Handwriting-Cursive. Ninety-five typically developing students and 6 students receiving special education services completed the Evaluation Tool of Children's Handwriting-Cursive (ETCH-C). Photographs were taken of their pencil grips while they wrote the alphabet. One-way ANOVAs were calculated to compare legibility rates and writing speeds by type of pencil grip. Ninety-nine of the students used one of four pencil grips including the dynamic tripod (38 students), the dynamic quadrupod (18), the lateral tripod (22), and the lateral quadrupod (21). One student used the four-finger pencil grip and one used the interdigital pencil grip. Mean cursive writing speeds were similar for all pencil grips except for the interdigital grasp. Speeds obtained were slower than recently published fourth-grade speeds ranging from a mean of 29.45 to 34.75 letters per minute. CONCLUSION. This study found the lateral quadrupod and four-finger pencil grips to be as functional as the dynamic tripod, lateral tripod, and dynamic quadrupod pencil grips. This study provides average handwriting speeds for fourth-grade students on the ETCH-C.
Motawar, Binal; Stinear, James W.; Lauer, Abigail W.; Ramakrishnan, V. Viswanathan; Seo, Na Jin
Grip relaxation is a voluntary action that requires an increase in short-interval intracortical inhibition (SICI) in healthy young adults, rather than a simple termination of excitatory drive. The way aging affects this voluntary inhibitory action and timing of grip relaxation is currently unknown. The objective of this study was to examine aging-related delays in grip relaxation and SICI modulation for the flexor digitorum superficialis (FDS) muscle during grip relaxation. The main finding was that young adults increased SICI to relax their grips, whereas older adults did not increase SICI with a prolonged grip relaxation time (prelaxation time). A secondary experiment showed that both young and older adults did not change H reflex excitability during grip relaxation. Our data suggest that grip relaxation is mediated by increased cortical inhibitory output in young adults, and aging-related impairment in increasing cortical inhibitory output may hamper timely cessation of muscle activity. Our data also suggest a lesser role of the spinal circuits in grip muscle relaxation. This knowledge may contribute to understanding of aging-related movement deterioration and development of interventions for improving modulation of SICI to improve muscle relaxation and movement coordination. PMID:26686531
Surke, Carsten; Ducommun Dit Boudry, Pascal; Vögelin, Esther
The loss of the upper extremity implicates a grave insult in the life of the involved person. To compensate for the loss of function different powered prosthetic devices are available. Ever since their first development 70 years ago numerous improvements in terms of size, weight and wearing comfort have been developed, but issues regarding the control of upper extremity prostheses remain. Slow grasping speed, limited grip positions and especially failure to provide a sensory feedback limit the acceptance in patients. Recent developments are aimed to allow a more intuitive control of the prosthetic device and to provide a sensory feedback to the amputee. Targeted reinnervation reassignes existing muscles to different peripheral nerves thereby enabling them to fulfill alternate functions. Implanting electrodes into muscle bellies of the forearm allows a more accurate control of the prosthesis. Promising results are being achieved by implanting nerve electrodes by establishing bilateral communication between patient and prosthesis. The following review summarizes the current developments of bionic prostheses in the upper extremity.
Fernández-de-Las-Peñas, César; Cleland, Joshua; Palacios-Ceña, María; Fuensalida-Novo, Stella; Pareja, Juan A; Alonso-Blanco, Cristina
Study Design Randomized parallel-group trial. Background Carpal tunnel syndrome (CTS) is a common pain condition that can be managed surgically or conservatively. Objective To compare the effectiveness of manual therapy versus surgery for improving self-reported function, cervical range of motion, and pinch-tip grip force in women with CTS. Methods In this randomized clinical trial, 100 women with CTS were randomly allocated to either a manual therapy (n = 50) or a surgery (n = 50) group. The primary outcome was self-rated hand function, assessed with the Boston Carpal Tunnel Questionnaire. Secondary outcomes included active cervical range of motion, pinch-tip grip force, and the symptom severity subscale of the Boston Carpal Tunnel Questionnaire. Patients were assessed at baseline and 1, 3, 6, and 12 months after the last treatment by an assessor unaware of group assignment. Analysis was by intention to treat, with mixed analyses of covariance adjusted for baseline scores. Results At 12 months, 94 women completed the follow-up. Analyses showed statistically significant differences in favor of manual therapy at 1 month for self-reported function (mean change, -0.8; 95% confidence interval [CI]: -1.1, -0.5) and pinch-tip grip force on the symptomatic side (thumb-index finger: mean change, 2.0; 95% CI: 1.1, 2.9 and thumb-little finger: mean change, 1.0; 95% CI: 0.5, 1.5). Improvements in self-reported function and pinch grip force were similar between the groups at 3, 6, and 12 months. Both groups reported improvements in symptom severity that were not significantly different at all follow-up periods. No significant changes were observed in pinch-tip grip force on the less symptomatic side and in cervical range of motion in either group. Conclusion Manual therapy and surgery had similar effectiveness for improving self-reported function, symptom severity, and pinch-tip grip force on the symptomatic hand in women with CTS. Neither manual therapy nor surgery resulted
Popević, Martin B; Janković, Srđan M; Borjanović, Srđan S; Jovičić, Slavica R; Tenjović, Lazar R; Milovanović, Aleksandar P S; Bulat, Petar
A frequently encountered exposure profile for hand-arm vibration in contemporary occupational setting comprises workers with a long history of intermittent exposure but without detectable signs of hand-arm vibration syndrome (HAVS). Yet, most of the published studies deal with developed HAVS cases, rarely discussing the biological processes that may be involved in degradation of manual dexterity and grip strength when it can be most beneficial - during the asymptomatic stage. In the present paper, a group of 31 male asymptomatic vibration-exposed workers (according to the Stockholm Workshop Scale) were compared against 30 male controls. They were tested using dynamometry and dexterimetry (modelling coarse and fine manual performance respectively) and cold provocation was done to detect possible differences in manual performance drop on these tests. The results showed reduced manual dexterity but no significant degradation in hand grip strength in the exposed subjects. This suggests that intermittent exposure profile and small cumulative vibration dose could only lead to a measurable deficit in manual dexterity but not hand grip strength even at non-negligible A(8) levels and long term exposures.
Teremetz, Maxime; Amado, Isabelle; Bendjemaa, Narjes; Krebs, Marie-Odile; Lindberg, Pavel G; Maier, Marc A
Whether upper limb sensorimotor control is affected in schizophrenia and how underlying pathological mechanisms may potentially intervene in these deficits is still being debated. We tested voluntary force control in schizophrenia patients and used a computational model in order to elucidate potential cerebral mechanisms underlying sensorimotor deficits in schizophrenia. A visuomotor grip force-tracking task was performed by 17 medicated and 6 non-medicated patients with schizophrenia (DSM-IV) and by 15 healthy controls. Target forces in the ramp-hold-and-release paradigm were set to 5 N and to 10% maximal voluntary grip force. Force trajectory was analyzed by performance measures and Principal Component Analysis (PCA). A computational model incorporating neural control signals was used to replicate the empirically observed motor behavior and to explore underlying neural mechanisms. Grip task performance was significantly lower in medicated and non-medicated schizophrenia patients compared to controls. Three behavioral variables were significantly higher in both patient groups: tracking error (by 50%), coefficient of variation of force (by 57%) and duration of force release (up by 37%). Behavioral performance did not differ between patient groups. Computational simulation successfully replicated these findings and predicted that decreased motor inhibition, together with an increased signal-dependent motor noise, are sufficient to explain the observed motor deficits in patients. PCA also suggested altered motor inhibition as a key factor differentiating patients from control subjects: the principal component representing inhibition correlated with clinical severity. These findings show that schizophrenia affects voluntary sensorimotor control of the hand independent of medication, and suggest that reduced motor inhibition and increased signal-dependent motor noise likely reflect key pathological mechanisms of the sensorimotor deficit.
Burgerhof, Johannes G M; Vasluian, Ecaterina; Dijkstra, Pieter U; Bongers, Raoul M; van der Sluis, Corry K
STUDY DESIGN: Cross-sectional. INTRODUCTION: Southampton Hand Assessment Procedure (SHAP) provides function scores for hand grips (prehensile patterns) and an overall score, the index of function (IOF). The underlying equations of SHAP are not publicly available, which induces opacity. Furthermore,
Schiele, Philippe; Le Nen, Dominique
Superficial and deep hand infections are frequent in general medical practice. Clinical examination is a crucial step for an adapted provided care. Most of the time, surgery is the only way to heal infections. However, in some cases (like bites), empiric antibiotherapy is first indicated to limit infection. Staphyloccocus aureus as well as Group Beta Streptococcus are the most frequently pathogenes associated with hand infections. Methicillin resistant S. Aureus must always be considered in the diagnoses. Whatever treatment is provided, clinical assessement must be repeated within two days. An early adaquated treatment prevent functional complications and in some cases death of the patients.
Noguchi, Takanori; Demura, Shinichi; Takahashi, Kenji; Demura, Gou; Mori, Yasunori
We examined the differences in muscle power between the dominant and nondominant upper limbs of 33 healthy, right-handed, university baseball players (mean age, 20.4 ± 1.1 years) with an average baseball experience >11 years. After measuring maximal voluntary contraction (MVC) of hand grip, elbow flexion, and shoulder internal rotation in both upper limbs, the muscle power of each joint was measured at 40%, 50%, and 60% MVC. No significant differences were observed in the main factors affecting MVC and elbow flexion power loads between dominant and nondominant upper limbs. For handgrip power, load factors at 40% MVC in the dominant hand were lower than those at 60% MVC in the same hand and those at 50% and 60% MVC in the nondominant hand. Significant differences were observed in shoulder internal rotation power between dominant and nondominant upper limbs, with the dominant limb having greater power at all loads. Correlations between muscle power of both upper limbs for handgrip and elbow flexion were significant and moderately high at all loads. For shoulder internal rotation power, the degree of correlation was significant and moderately high at 40% MVC but low to moderate at 50% and 60% MVC. Therefore, baseball players have marked lateral dominance in shoulder internal rotation power unlike handgrip and elbow flexion power, although the relationship between shoulder internal rotation muscle powers of both upper limbs becomes lower with increasing load. The dominance of muscle power of each joint varied even in the same upper limb. It is thus beneficial for baseball players to train with even loads on both arms or adopt simultaneous workout of both arms after adjusting for strength differences.
Uma Shankar Agarwal
Full Text Available Hand eczema is often a chronic, multifactorial disease. It is usually related to occupational or routine household activities. Exact etiology of the disease is difficult to determine. It may become severe enough and disabling to many of patients in course of time. An estimated 2-10% of population is likely to develop hand eczema at some point of time during life. It appears to be the most common occupational skin disease, comprising 9-35% of all occupational diseases and up to 80% or more of all occupational contact dermatitis. So, it becomes important to find the exact etiology and classification of the disease and to use the appropriate preventive and treatment measures. Despite its importance in the dermatological practice, very few Indian studies have been done till date to investigate the epidemiological trends, etiology, and treatment options for hand eczema. In this review, we tried to find the etiology, epidemiology, and available treatment modalities for chronic hand eczema patients.
Full Text Available Background and Aim: Osteoblastoma is one of the rarest primary bone tumors. Although, small bones of the hands and feet are the third most common location for this tumor, the hand involvement is very rare and few case observations were published in the English-language literature. Materials and Methods: In this study, we report five cases of benign osteoblastoma of the hand, 3 in metacarpals and two in phalanxes. The clinical feature is not specific. The severe nocturnal, salicylate-responsive pain is not present in patients with osteoblastoma. The pain is dull, persistent and less localized. The clinical course is usually long and there is often symptoms for months before medical attention are sought. Swelling is a more persistent finding in osteoblastoma of the hand that we found in all of our patients. The radiologic findings are indistinctive, so preoperative diagnosis based on X-ray appearance is difficult. In all of our 5 cases, we fail to consider osteoblastoma as primary diagnosis. Pathologically, osteoblastoma consisting of a well-vascularized connective tissue stroma in which there is active production of osteoid and primitive woven bone. Treatment depends on the stage and localization of the tumor. Curettage and bone grafting is sufficient in stage 1 or stage 2, but in stage 3 wide resection is necessary for prevention of recurrence. Osteosarcoma is the most important differential diagnosis that may lead to inappropriate operation.
Ibler, K.S.; Jemec, G.B.E.; Flyvholm, M.-A.
/materials/methods. A survey of 3181 healthcare workers was performed. Data were analysed with logistic regression. Data on sick leave and notification to the authorities were obtained. Results. The response rate was 71% (2274 of 3181). The 1-year prevalence of hand eczema was 21%, and was positively associated with atopic...
THE two most amazing things on the planet may well be the human brain and human hands. When they work together, the results can be enchanting. At an international folk art fair held recently in Beijing, artisans and masters from Japan, India, Switzerland, Peru, South
Oppewal, Alyt; Hilgenkamp, Thessa I. M.; van Wijck, Ruud; Evenhuis, Heleen M.
Grip strength is an important predictor of several health outcomes in the general older population. Grip strength assessment is feasible and reliable in older adults with intellectual disabilities (ID), which makes it a valuable measurement for application in this population. The purpose of this study was to investigate the effect of handedness on…
Tashiro, Yuto; Fukumoto, Takahiko; Uritani, Daisuke; Matsumoto, Daisuke; Nishiguchi, Shu; Fukutani, Naoto; Adachi, Daiki; Hotta, Takayuki; Morino, Saori; Shirooka, Hidehiko; Nozaki, Yuma; Hirata, Hinako; Yamaguchi, Moe; Aoyama, Tomoki
[Purpose] This study investigated the relationship between toe grip strength and foot posture in children. [Subjects and Methods] A total of 619 children participated in this study. The foot posture of the participants was measured using a foot printer and toe grip strength was measured using a toe grip dynamometer. Children were classified into 3 groups; flatfoot, normal, and high arch, according to Staheli’s arch index. The differences in demographic data and toe grip strength among each foot posture group were analyzed by analysis of variance. Additionally, toe grip strength differences were analyzed by analysis of covariance, adjusted to body mass index, age, and gender. [Results] The number of participants classified as flatfoot, normal, and high arch were 110 (17.8%), 468 (75.6%), and 41 (6.6%), respectively. The toe grip strength of flatfoot children was significantly lower than in normal children, as shown by both analysis of variance and analysis of covariance. [Conclusion] A significant difference was detected in toe grip strength between the low arch and normal foot groups. Therefore, it is suggested that training to increase toe grip strength during childhood may prevent the formation of flat feet or help in the development of arch. PMID:26696732
Gegeckaite, Asta; Moon, Jack; Hansen, Hans Nørgaard
In the micro scale, gripping devices are working in the different way. New forces, working in the micro scale, like van der Waals, surface tension and electrostatics are influencing the gripping process. Handling of micro or even nano sized objects can be easily in the nature. Different types of ...
... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Typical Handbrake Actuator Showing Grip Dimension 5 Figure 5 to Part 1512 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS... Actuator Showing Grip Dimension EC03OC91.072 ...
Gegeckaite, Asta; Moon, Jack; Hansen, Hans Nørgaard
In the micro scale, gripping devices are working in the different way. New forces, working in the micro scale, like van der Waals, surface tension and electrostatics are influencing the gripping process. Handling of micro or even nano sized objects can be easily in the nature. Different types of ...
Bompa, T O; Hebbelinck, M; Van Gheluwe, B
The velocity of the rowing boat appears to depend on the force which the athlete applies at the handle of the oar. Although force is generated by legs, upper body, and arms, the latter are the only limbs which actually transmit and apply the force against the oar. The force output of the arms seem to be a function of the forearm position used by the athlete while gripping the oar. The traditional gripping technique is with the forearms in pronation. This technique was never challenged or scientifically researched to see whatever a modified one might lead to better efficiency. Consequently, the purpose of this investigation was to analyze whether athletes' force output differed if the gripping technique was changed from pronation to a semiprone grip (one arm prone, the other semiprone). Under the specific conditions of this investigation it was demonstrated that the semiprone position was generating greater force output, thus being superior to the classical prone grip.
Goodson, Alexander; McGregor, Alison H; Douglas, Jane; Taylor, Peter
Methods of assessing functional impairment in arthritic hands include pain assessments and disability scoring scales which are subjective, variable over time and fail to take account of the patients' need to adapt to deformities. The aim of this study was to evaluate measures of functional strength and joint motion in the assessment of the rheumatoid (RA) and osteoarthritic (OA) hand. Ten control subjects, ten RA and ten OA patients were recruited for the study. All underwent pain and disability scoring and functional assessment of the hand using measures of pinch/grip strength and range of joint motion (ROM). Functional assessments including ROM analyses at interphalangeal (IP), metacarpophalangeal (MCP) and wrist joints along with pinch/grip strength clearly discriminated between patient groups (RA vs. OA MCP ROM P<0.0001), pain and disability scales were unable to. In the RA there were demonstrable relationships between ROM measurements and disability (R2=0.31) as well as disease duration (R2=0.37). Intra-patient measures of strength were robust whereas inter-patient comparisons showed variability. In conclusion, pinch/grip strength and ROM are clinically reproducible assessments that may more accurately reflect functional impairment associated with arthritis.
... 29 Labor 8 2010-07-01 2010-07-01 false Hand tools. 1926.301 Section 1926.301 Labor Regulations...) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Tools-Hand and Power § 1926.301 Hand tools. (a) Employers shall not issue or permit the use of unsafe hand tools. (b) Wrenches, including adjustable, pipe,...
Clamann, Michael; Zhu, Biwen; Beaver, Leah; Taylor, Kinley; Kaber, David
The rear-facing Infant Car Seat (ICS) is designed to meet federal requirements for transporting children less than 1 year old. Typical use includes transfer in and out of a vehicle, which is shown to be a difficult lift. Despite the frequency of this lift, manufacturers provide little guidance for users. Review of relevant literature suggested an ICS featuring an angled handle, promoting a neutral wrist posture, would increase grip stability and decrease lifting effort. Popular press suggested a foot-in-car stance for the ICS lift would do the same. An experiment was conducted in which wrist deviations from neutral posture were recorded along with lifting muscle activation levels (multiple flexor muscles and biceps brachii) and overall perceived exertion for straight versus a new bent handle design and conventional stance versus foot-in-car. Foot position was examined to test the recommendations in the popular press. Surprisingly, wrist deviation was not significantly affected by the new bent handle design (due to compensatory behavior with the straight handle) but was related to foot placement (p=0.04). Results revealed the bent handle to significantly reduce flexor activation compared with the straight handle (p=0.0003); however, the level of biceps activation increased. Biceps activation also significantly increased for foot-in-car stance (p=0.035) but not flexor activation. In general, the bent handle enabled the user to lift the ICS with a steadier grip and less effort. Copyright © 2011 Elsevier Ltd and The Ergonomics Society. All rights reserved.
van der Linde, H; Snoek, GJ; Knoop, HA; Mulder, T
To determine whether surgical key grip reinforcement actually leads to a better movement ability we developed a procedure for the kinematic analysis of manual skill following hand surgery in tetraplegia. The functional results of surgery in 5 cases were examined by the kinematic analysis of drawing
Full Text Available Background. Trigger finger (TF is a common hand pathology frequently encountered in hand clinics. Occupational therapists predominantly assess TF symptoms as opposed to using standardized hand functioning assessments. The purpose of this study was to assess the construct validity of dexterity and grip strength assessments for clients with TF. Method. Sixty-three participants with TF and 66 healthy controls were administered the Functional Dexterity Test (FDT, Purdue Pegboard Test (PPT, and Jamar® Hydraulic Hand Dynamometer (JD and completed the Disabilities of Arm Shoulder and Hand questionnaire (DASH. TF symptoms were graded using the Quinnell classification. Results. Statistically significant differences were found between the groups in dexterity and grip strength. A statistically significant difference between the three TF grades was found on the PPT. All three test scores were moderately correlated with the DASH scores. Conclusion. This study provides innovative evidence for the validity of common hand function assessments for individuals with TF and recommends incorporating these tools in clinical practice. Further research is needed with larger samples and better representation of each TF clinical grade.
Gray, M; Di Brezzo, R; Fort, I L
The purpose of this 48-week exercise intervention was designed to examine the effects of power and resistance training on bone mineral density (BMD). Premenopausal women were recruited and randomly assigned to either a power (N.=8) or resistance (N.=11) training group. The power exercises included jumping rope, skipping, hopping, and other power-type exercises. The resistance training group performed 8-10 whole-body strengthening exercises at 70% one-repetition maximum (1RM). Before and after the exercise intervention, BMD was measured via dual energy x-ray absorptiometry (DXA) for the total-body, lumbar spine, left femoral neck, and left greater trochanter. Muscular strength was measured by hand grip dynamometer and 1RM of chest press and leg press. Muscular power was assessed by the Margaria-Kalamen stair climb test. Data were analyzed using repeated measures ANOVA. There were no statistical differences between the two training groups for any of the BMD measurements. Chest press strength was different between the two groups, increasing 6.41 and 1.1kg for the resistance and power groups, respectively over the course of the training period (F[1.15]=9.44, P<0.01). There was a significant time effect for leg press 1RM (F[1.15]=6.04, P=0.03). The participants increased by 12.37kg after the 48-week intervention. Hand grip strength also increased after the study intervention (F[1.16]=46.32, P<0.01). The results of this study suggest that power and resistance training are comparable techniques for maintaining bone density.
Flindall, Jason W; Stone, Kayla D; Gonzalez, Claudia L R
We have recently shown that actions with similar kinematic requirements, but different end-state goals may be supported by distinct neural networks. Specifically, we demonstrated that when right-handed individuals reach-to-grasp food items with intent to eat, they produce smaller maximum grip apertures (MGAs) than when they grasp the same item with intent to place it in a location near the mouth. This effect was restricted to right-handed movements; left-handed movements showed no difference between tasks. The current study investigates whether (and to which side) the effect may be lateralized in left-handed individuals. Twenty-one self-identified left-handed participants grasped food items of three different sizes while grasp kinematics were captured via an Optotrak Certus motion capture array. A main effect of task was identified wherein the grasp-to-eat action generated significantly smaller MGAs than did the grasp-to-place action. Further analysis revealed that similar to the findings in right-handed individuals, this effect was significant only during right-handed movements. Upon further inspection however, we found individual differences in the magnitude and direction of the observed lateralization. These results underscore the evolutionary significance of the grasp-to-eat movement in producing population-level right-handedness in humans as well as highlighting the heterogeneity of the left-handed population.
Arnould, Carlyne; Bleyenheuft, Yannick; Thonnard, Jean-Louis
Brain lesions may disturb hand functioning in children with cerebral palsy (CP), making it difficult or even impossible for them to perform several manual activities. Most conventional treatments for hand dysfunction in CP assume that reducing the hand dysfunctions will improve the capacity to manage activities (i.e., manual ability, MA). The aim of this study was to investigate the directional relationships (direct and indirect pathways) through which hand skills influence MA in children with CP. A total of 136 children with CP (mean age: 10 years; range: 6–16 years; 35 quadriplegics, 24 diplegics, 77 hemiplegics) were assessed. Six hand skills were measured on both hands: touch-pressure detection (Semmes–Weinstein esthesiometer), stereognosis (Manual Form Perception Test), proprioception (passive mobilization of the metacarpophalangeal joints), grip strength (GS) (Jamar dynamometer), gross manual dexterity (GMD) (Box and Block Test), and fine finger dexterity (Purdue Pegboard Test). MA was measured with the ABILHAND-Kids questionnaire. Correlation coefficients were used to determine the linear associations between observed variables. A path analysis of structural equation modeling was applied to test different models of causal relationships among the observed variables. Purely sensory impairments did seem not to play a significant role in the capacity to perform manual activities. According to path analysis, GMD in both hands and stereognosis in the dominant hand were directly related to MA, whereas GS was indirectly related to MA through its relationship with GMD. However, one-third of the variance in MA measures could not be explained by hand skills. It can be concluded that MA is not simply the integration of hand skills in daily activities and should be treated per se, supporting activity-based interventions. PMID:24782821
Kouhzad Mohammadi, Hosein; Khademi Kalantari, Khosro; Naeimi, Sedighe Sadat; Pouretezad, Mohammad; Shokri, Esmaeil; Tafazoli, Mojdeh; Dastjerdi, Mahboobeh; Kardooni, Leila
Background: Due to the fundamental role of gripping in most upper limb activities, grip strength promotion is a chief goal in the treatment of patients with upper limb musculoskeletal disorders. Kinesio taping is a novel and effective therapeutic technique believed to facilitate muscle contraction through stimulating mechanoreceptors and increasing the sensory feedback around the taped region. Objectives: The present study aimed to identify the best region (flexor, extensor and flexor/extensor regions) and time (immediate, 0.5, 1, 1.5, and 2 hours) of forearm Kinesio taping to obtain the maximum improvement in grip strength. Materials and Methods: In this longitudinal study, 40 healthy men and women (the mean age of 22.3 ± 2.19 years) were selected among students of Shahid Beheshti University of Medical Sciences, Tehran, Iran by simple, nonrandom sampling method. A dynamometer was used to measure grip strength immediately and every 30 minutes during the two hours after I-shaped application of tape (with 50% stretch) to the flexor, extensor, and flexor/extensor forearm muscles. Results: Grip strength was significantly increased in various muscle groups for males (P = 0.002) and females (P = 0.000) of the forearm and at different intervals for males (P = 0.000) and females (P = 0.000). Moreover, in both men and women, tape application to the extensor region provided greater grip strength compared to taping of the flexor and flexor/extensor regions (P = 0.000 for both). Furthermore, the maximum increase in grip strength were 0.5 (10.8% increase, P = 0.001) and 1.5 h (23.9% increase, P = 0.000) after taping in males and females, respectively. Conclusions: Taping the extensor region of forearm is recommended to achieve higher grip strength. Although grip strength increased at a slower pace in females than males, the final values were higher in women. PMID:25389492
Elmholdt, Claus Westergård; Fogsgaard, Morten
In this chapter, we will explore the dynamics of power in processes of creativity, and show its paradoxical nature as both a bridge and a barrier to creativity in organisations. Recent social psychological experimental research (Slighte, de Dreu & Nijstad, 2011) on the relation between power...... and creativity suggests that when managers give people the opportunity to gain power and explicate that there is reason to be more creative, people will show a boost in creative behaviour. Moreover, this process works best in unstable power hierarchies, which implies that power is treated as a negotiable...... and floating source for empowering people in the organisation. We will explore and discuss here the potentials, challenges and pitfalls of power in relation to creativity in the life of organisations today. The aim is to demonstrate that power struggles may be utilised as constructive sources of creativity...
White, Olivier; Van Loon, ing.. Jack J. W. A.; Thonnard, Jean-Louis; Hermsdorfer, Joachim; Lefevre, Philippe
One remarkable capacity of utilizing common tools appropriately as soon as we grasp them relies on the ability to determine in advance the grip force (GF) required to handle them in relation to their mechanical properties and the surrounding environment. This anticipatory strategy avoids the uncompressible delays in the feedback system. The predictive control of GF is made possible because the nervous system can learn, store and then select the internal representations of the dynamics of innumerable objects, known as internal models. Beside this flexibility, the nervous system's ability to learn different task dynamics is often limited in classical robotic experiments The environment itself can be profoundly modified in altered gravity or centrifugation. The few studies that investigated motor adaptation in such contexts did not consider the interaction between gravitational phases and even less the transitions across environments. Here, we tested subject's abilities to adapt to levels of gravitational fields generated by a human centrifuge. In Experiment 1, seven subjects performed 4 lifting trials in each gravitational phase (1 to 2.5g and then 2.5 to 1g by steps of 0.5g) with a 0.12 kg instrumented object. In Experiment 2, six subjects performed vertical oscillations of the object during transitions between 1 and 3g (0.5g steps, ascending and descending phases, profile repeated twice). We continuously measured GF, load force (LF) and ambient gravity. We hypothesized that participants were able to predictively adjust GF to the new environment. In Experiment 1, participants adjusted their GF proportionally to gravity and decreased GF across trials within a given gravitational environment. Preload phases decreased over time from 300ms to 50ms irrespective of gravity. We quantified the abilities of participants to switch across environments by subtracting GF recorded in the last trial in the current gravity level from GF during the first trial in the new environment
Albers, Lynn Alwine
Background In order to eliminate the fear-factor associated with learning FluidMechanics, a new instructional method was created. The new method is neatly packaged into hands-on activities (as defined in this dissertation) in order to ease implementation and dissemination into an engineering class. Because of variations in learning and teaching styles of students and lecturers , the hands-on activities are designed to help the lecturer communicate key concepts to a wider spectrum of students. Typically engineering lectures are biased towards intuitive, verbal, reflective and sequential learners whereas few engineering students fall into these categories.  The hands-on activities are meant to bridge the communication gap resulting in a positive educational experience. Purpose In order to assess the impact of the new instructional method, a new engineering education experimental design was created. Engineering Education research is very interdisciplinary in nature and therefore requires cooperation from multiple Colleges including, but not limited to, Engineering, Education, and Science (Statistics). Design/Method Two groups of engineering students were allocated to test the hypothesis, "Does being exposed to hands-on activities (a new instructional method) in a section of MAE 308 - Fluid Mechanics result in higher student achievement?" Comparison of the quiz results between the control group and experimental group assessed the effectiveness of the hands-on activities. The problems within each quiz correlated to a level of Bloom's Taxonomy. A comparison of the results on the problems assessed which level of Bloom's were impacted. NHST was performed to determine statistical significance while the effect size was calculated to determine practical significance. Results The hands-on activities have a positive effect on learning. 3.30% more students per class perform better on each problem on each quiz. The hands-on activity, Rainbow Layer Cake, was a superstar
Knosp, Brian W.; Li, P. Peggy; Vu, Quoc A.; Turk, Francis J.; Shen, Tsae-Pyng J.; Hristova-Veleva, Svetla M.; Licata, Stephen J.; Poulsen, William L.
Satellite observations can play a very important role in airborne field campaigns, since they provide a comprehensive description of the environment that is essential for the experiment design, flight planning, and post-experiment scientific data analysis. In the past, it has been difficult to fully utilize data from multiple NASA satellites due to the large data volume, the complexity of accessing NASA s data in near-real-time (NRT), as well as the lack of software tools to interact with multi-sensor information. The JPL GRIP Portal is a Web portal that serves a comprehensive set of NRT observation data sets from NASA and NOAA satellites describing the atmospheric and oceanic environments related to the genesis and intensification of the tropical storms in the North Atlantic Ocean. Together with the model forecast data from four major global atmospheric models, this portal provides a useful tool for the scientists and forecasters in planning and monitoring the NASA GRIP field campaign during the 2010 Atlantic Ocean hurricane season. This portal uses the Google Earth plug-in to visualize various types of data sets, such as 2D maps, wind vectors, streamlines, 3D data sets presented at series of vertical cross-sections or pointwise vertical profiles, and hurricane best tracks and forecast tracks. Additionally, it allows users to overlap multiple data sets, change the opacity of each image layer, generate animations on the fly with selected data sets, and compare the observation data with the model forecast using two independent calendars. The portal also provides the capability to identify the geographic location of any point of interest. In addition to supporting the airborne mission planning, the NRT data and portal will serve as a very rich source of information during the post-field campaign analysis stage of the airborne experiment. By including a diverse set of satellite observations and model forecasts, it provides a good spatial and temporal context for the
Full Text Available Recent studies about sensorimotor control of the human hand have focused on how dexterous manipulation is learned and generalized. Here we address this question by testing the extent to which learned manipulation can be transferred when the contralateral hand is used and/or object orientation is reversed. We asked subjects to use a precision grip to lift a grip device with an asymmetrical mass distribution while minimizing object roll during lifting by generating a compensatory torque. Subjects were allowed to grasp anywhere on the object's vertical surfaces, and were therefore able to modulate both digit positions and forces. After every block of eight trials performed in one manipulation context (i.e., using the right hand and at a given object orientation, subjects had to lift the same object in the second context for one trial (transfer trial. Context changes were made by asking subjects to switch the hand used to lift the object and/or rotate the object 180° about a vertical axis. Therefore, three transfer conditions, hand switch (HS, object rotation (OR, and both hand switch and object rotation (HS+OR, were tested and compared with hand matched control groups who did not experience context changes. We found that subjects in all transfer conditions adapted digit positions across multiple transfer trials similar to the learning of control groups, regardless of different changes of contexts. Moreover, subjects in both HS and HS+OR group also adapted digit forces similar to the control group, suggesting independent learning of the left hand. In contrast, the OR group showed significant negative transfer of the compensatory torque due to an inability to adapt digit forces. Our results indicate that internal representations of dexterous manipulation tasks may be primarily built through the hand used for learning and cannot be transferred across hands.
Fu, Qiushi; Choi, Jason Y; Gordon, Andrew M; Jesunathadas, Mark; Santello, Marco
Recent studies about sensorimotor control of the human hand have focused on how dexterous manipulation is learned and generalized. Here we address this question by testing the extent to which learned manipulation can be transferred when the contralateral hand is used and/or object orientation is reversed. We asked subjects to use a precision grip to lift a grip device with an asymmetrical mass distribution while minimizing object roll during lifting by generating a compensatory torque. Subjects were allowed to grasp anywhere on the object's vertical surfaces, and were therefore able to modulate both digit positions and forces. After every block of eight trials performed in one manipulation context (i.e., using the right hand and at a given object orientation), subjects had to lift the same object in the second context for one trial (transfer trial). Context changes were made by asking subjects to switch the hand used to lift the object and/or rotate the object 180° about a vertical axis. Therefore, three transfer conditions, hand switch (HS), object rotation (OR), and both hand switch and object rotation (HS+OR), were tested and compared with hand matched control groups who did not experience context changes. We found that subjects in all transfer conditions adapted digit positions across multiple transfer trials similar to the learning of control groups, regardless of different changes of contexts. Moreover, subjects in both HS and HS+OR group also adapted digit forces similar to the control group, suggesting independent learning of the left hand. In contrast, the OR group showed significant negative transfer of the compensatory torque due to an inability to adapt digit forces. Our results indicate that internal representations of dexterous manipulation tasks may be primarily built through the hand used for learning and cannot be transferred across hands.
Danna-Dos Santos, Alessander; Poston, Brach; Jesunathadas, Mark; Bobich, Lisa R.; Hamm, Thomas M.; Santello, Marco
Fingertip force control requires fine coordination of multiple hand muscles within and across the digits. While the modulation of neural drive to hand muscles as a function of force has been extensively studied, much less is known about the effects of fatigue on the coordination of simultaneously active hand muscles. We asked eight subjects to perform a fatiguing contraction by gripping a manipulandum with thumb, index, and middle fingers while matching an isometric target force (40% maximal ...
BACKGROUND: Given the variety of available hand-held dynamometers and their different handle shapes, reliability studies are needed. Objectives: To compare the accuracy and reliability between three different hand-held dynamometers and analyze the influence of their handles on grip strength. Methods: The tests were performed with the Jamar® dynamometer, the Takei® dynamometer and the EMG System Manual Transducer with modified handle. Eighteen healthy volunteers aged 20.0±1.3 years without his...
Makin, Tamar R; Holmes, Nicholas P; Ehrsson, H Henrik
Where are my hands? The brain can answer this question using sensory information arising from vision, proprioception, or touch. Other sources of information about the position of our hands can be derived from multisensory interactions (or potential interactions) with our close environment, such as when we grasp or avoid objects. The pioneering study of multisensory representations of peripersonal space was published in Behavioural Brain Research almost 30 years ago [Rizzolatti G, Scandolara C, Matelli M, Gentilucci M. Afferent properties of periarcuate neurons in macaque monkeys. II. Visual responses. Behav Brain Res 1981;2:147-63]. More recently, neurophysiological, neuroimaging, neuropsychological, and behavioural studies have contributed a wealth of evidence concerning hand-centred representations of objects in peripersonal space. This evidence is examined here in detail. In particular, we focus on the use of artificial dummy hands as powerful instruments to manipulate the brain's representation of hand position, peripersonal space, and of hand ownership. We also review recent studies of the 'rubber hand illusion' and related phenomena, such as the visual capture of touch, and the recalibration of hand position sense, and discuss their findings in the light of research on peripersonal space. Finally, we propose a simple model that situates the 'rubber hand illusion' in the neurophysiological framework of multisensory hand-centred representations of space.
Giboin, Louis-Solal; Lackmy-Vallée, Alexandra; Burke, David; Marchand-Pauvert, Véronique
In humans, propriospinal neurons located at midcervical levels receive peripheral and corticospinal inputs and probably participate in the control of grip tasks, but their role in reaching movements, as observed in cats and primates, is still an open question. The effect of ulnar nerve stimulation on flexor carpi radialis (FCR) motor evoked potential (MEP) was tested during reaching tasks and tonic wrist flexion. Significant MEP facilitation was observed at the end of reach during reach-to-grasp but not during grasp, reach-to-point, or tonic contractions. MEP facilitation occurred at a longer interstimulus interval than expected for convergence of corticospinal and afferent volleys at motoneuron level and was not paralleled by a change in the H-reflex. These findings suggest convergence of the two volleys at propriospinal level. Ulnar-induced MEP facilitation was observed when conditioning stimuli were at 0.75 motor response threshold (MT), but not 1 MT. This favors an increased excitability of propriospinal neurons rather than depression of their feedback inhibition, as has been observed during tonic power grip tasks. It is suggested that the ulnar-induced facilitation of FCR MEP during reach may be due to descending activation of propriospinal neurons, assisting the early recruitment of large motoneurons for rapid movement. Because the feedback inhibitory control is still open, this excitation can be truncated by cutaneous inputs from the palmar side of the hand during grasp, thus assisting movement termination. It is concluded that the feedforward activation of propriospinal neurons and their feedback control may be involved in the internal model, motor planning, and online adjustments for reach-to-grasp movements in humans.
Bhargava Arti S
Full Text Available Abstract Background Lateral epicondylitis is a common sports injury of the elbow caused due to altered muscle activation during repetitive wrist extension in many athletic and non-athletic endeavours. The amount of muscle activity and timing of contraction eventually is directly dependent upon joint position during the activity. The purpose of our study was to compare the grip strength in athletes with lateral epicondylalgia in two different wrist extension positions and compare them between involved and uninvolved sides of athletes and non-athletes. Methods An assessor-blinded case-control study of eight athletes and twenty-two non-athletes was done. The grip strength was measured using JAMAR® hand dynamometer in kilograms-force at 15 degrees (slightly extended and 35 degrees (moderately extended wrist extension positions (maintained by wrist splints on both involved and uninvolved sides of athletes and non-athletes with unilateral lateral epicondylitis of atleast 3 months duration. Their pain was to be elicited with local tenderness and two of three tests being positive- Cozen's, Mill's manoeuvre, resisted middle finger extension tests. For comparisons of grip strength, Wilcoxon signed rank test was used for within-group comparison (between 15 and 35 degrees wrist extension positions and Mann-Whitney U test was used for between-group (athletes vs. non-athletes comparisons at 95% confidence interval and were done using SPSS 11.5 for Windows. Results Statistically significant greater grip strength was found in 15 degrees (27.75 ± 4.2 kgms in athletes; 16.45 ± 4.2 kgms in non-athletes wrist extension than at 35 degrees (25.25 ± 3.53 kgm in athletes and 14.18 ± 3.53 kgm in non-athletes. The athletes had greater grip strength than non-athletes in each of test positions (11.3 kgm at 15 degrees and 11.07 kgm at 35 degrees measured. There was also a significant difference between involved and uninvolved sides' grip strength at both wrist
Byrnes, Greg; Jayne, Bruce C.
On the steep surfaces that are common in arboreal environments, many types of animals without claws or adhesive structures must use muscular force to generate sufficient normal force to prevent slipping and climb successfully. Unlike many limbed arboreal animals that have discrete gripping regions on the feet, the elongate bodies of snakes allow for considerable modulation of both the size and orientation of the gripping region. We quantified the gripping forces of snakes climbing a vertical cylinder to determine the extent to which their force production favoured economy or safety. Our sample included four boid species and one colubrid. Nearly all of the gripping forces that we observed for each snake exceeded our estimate of the minimum required, and snakes commonly produced more than three times the normal force required to support their body weight. This suggests that a large safety factor to avoid slipping and falling is more important than locomotor economy. PMID:25142200
Full Text Available Rheumatoid arthritis (RA often results in impairments in upper extremities, especially in the small joints of hand. Involvement of hand brings limitations in activities of daily living. However, it is commonly observed that patient-reported functional status of hand does not always corresponds to their actual physical performance in the clinical setting. The aim of this pilot study is to investigate the relationship between patient self-reported and objectively measured hand functions in patients with RA. Twenty-six patients (51±13 years with RA diagnosis participated in the study. Hand grip and pinch (lateral, bipod, tripod strengths were measured and Jebsen Hand Function Test (JHFT was performed for objective functional performance. Duruöz Hand Index and Beck Depression Inventory - Turkish version were completed by patients. Grip and all three-pinch strength results significantly correlated with Duruöz Hand Index scores (p<0.05. JHFT results except the sentence writing also correlated with the Duruöz scores (p<0.05. Our results showed that self-reported outcome scales might be used for determining functional level of hand in patients with RA in rheumatology practice. Objective quantitative functional tests are the best methods in evaluating functional level of hand, but require valid and reliable equipment with accurate calibration. Therefore, in case of unavailability of objective assessment tools, patient-reported scales may also reflect the real status of hand functions.
Lukas L. Imbach
Conclusion: The time-locked suppression of beta oscillatory activity in the STN is in line with previous reports of beta ERD prior to voluntary movements. Our results show that the STN is involved in anticipatory grip force control in PD patients. The difference in the phasic beta ERD between the two tasks and the reduction of cortico-subthalamic synchronization suggests that qualitatively different neuronal network states are involved in different grip force control tasks.
Lu, Wei; Ziff, Edward B
PICK1 and ABP/GRIP bind to the AMPA receptor (AMPAR) GluR2 subunit C terminus. Transfer of the receptor from ABP/GRIP to PICK1, facilitated by GluR2 S880 phosphorylation, may initiate receptor trafficking. Here we report protein interactions that regulate these steps. The PICK1 BAR domain interacts intermolecularly with the ABP/GRIP linker II region and intramolecularly with the PICK1 PDZ domain. Binding of PKCalpha or GluR2 to the PICK1 PDZ domain disrupts the intramolecular interaction and facilitates the PICK1 BAR domain association with ABP/GRIP. Interference with the PICK1-ABP/GRIP interaction impairs S880 phosphorylation of GluR2 by PKC and decreases the constitutive surface expression of GluR2, the NMDA-induced endocytosis of GluR2, and recycling of internalized GluR2. We suggest that the PICK1 interaction with ABP/GRIP is a critical step in controlling GluR2 trafficking.
Based on an analysis of a real line fault, the switch-on and switch-off principle for relaying protection in similar hand-in-hand power network is discussed and solutions to hardware and software for realizing unattended substations in such networks are proposed.%根据一次实际线路故障计算分析，讨论类似的手拉手供电网继电保护的投退原则，并就此网中的变电站实现无人值守时应注意的软、硬件问题提出解决办法。
Księżopolska-Orłowska, Krystyna; Kasprzak, Katarzyna; Gaszewska, Ewa; Rodkiewicz-Bogusławska, Agnieszka; Sokołowska, Beata
Objectives The hand is one of the main elements of the rehabilitation of patients with rheumatoid arthritis (RA) due to deformities, which occur in approximately 90% of patients. It is a serious problem, both in the psychological and functional aspect, connected with muscle strength reduction, a limited range of motion and non-acceptance of the changes in the shape of the limb. The study aimed to assess the effect of rehabilitation on the function of the hand in rheumatoid arthritis. Material and methods The study group consisted of 40 women with RA. The patients had been previously treated at the Rehabilitation Department of the National Institute of Geriatrics, Rheumatology and Rehabilitation in Warsaw. The study group underwent 3 weeks of rehabilitation involving individual therapy, exercises with equipment, patient education and physical therapy. The control group included women without a diagnosis of RA, hands pain-free and fully mobile. In both groups the hand was assessed for grip value, grip quality and manipulative ability. In the study group the basis of pain intensity was noted. The measurements were performed twice – prior to the rehabilitation and after 3 weeks of rehabilitation in women with RA and once in women without hand problems. Results The results obtained revealed marked limitation of hand function in patients with rheumatoid arthritis. The treatment resulted in an improvement of all assessed parameters except cylindrical grip, in which only a part of the findings was statistically significant. Conclusions The analysis of the study material showed that appropriately adjusted and conducted hand physiotherapy in women with rheumatoid arthritis contributed to the improvement of its function by pain reduction, improved value and quality of grip, and also increased manipulative ability. PMID:28115778
Full Text Available Objectives: The hand is one of the main elements of the rehabilitation of patients with rheumatoid arthritis (RA due to deformities, which occur in approximately 90% of patients. It is a serious problem, both in the psychological and functional aspect, connected with muscle strength reduction, a limited range of motion and non-acceptance of the changes in the shape of the limb. The study aimed to assess the effect of rehabilitation on the function of the hand in rheumatoid arthritis. Material and methods: The study group consisted of 40 women with RA. The patients had been previously treated at the Rehabilitation Department of the National Institute of Geriatrics, Rheumatology and Rehabilitation in Warsaw. The study group underwent 3 weeks of rehabilitation involving individual therapy, exercises with equipment, patient education and physical therapy. The control group included women without a diagnosis of RA, hands pain-free and fully mobile. In both groups the hand was assessed for grip value, grip quality and manipulative ability. In the study group the basis of pain intensity was noted. The measurements were performed twice – prior to the rehabilitation and after 3 weeks of rehabilitation in women with RA and once in women without hand problems. Results : The results obtained revealed marked limitation of hand function in patients with rheumatoid arthritis. The treatment resulted in an improvement of all assessed parameters except cylindrical grip, in which only a part of the findings was statistically significant. Conclusions : The analysis of the study material showed that appropriately adjusted and conducted hand physiotherapy in women with rheumatoid arthritis contributed to the improvement of its function by pain reduction, improved value and quality of grip, and also increased manipulative ability.
Ambike, S; Zhou, T; Zatsiorsky, V M; Latash, M L
This study used the framework of the referent configuration hypothesis and slow changes in the external conditions during vertical oscillation of a hand-held object to infer the characteristics of hypothetical control variables. The study had two main objectives: (1) to show that hypothetical control variables, namely, referent coordinates and apparent stiffness of vertical hand position and grip force can be measured in an experiment; and (2) to establish relation(s) between these control variables that yield the classic grip-force-load-force coupling. Healthy subjects gripped a handle and performed vertical oscillations between visual targets at one of five metronome-prescribed frequencies. A HapticMaster robot was used to induce slow changes in the vertical force applied to the handle, while the size of the handle was changed slowly leading to changes in the grip aperture. The subjects were instructed not to react to possible changes in the external forces. A linear, second-order model was used to reconstruct the referent coordinate and apparent stiffness values for each phase of the vertical oscillation cycle using across-cycle regressions. The reconstructed time profiles of the referent coordinates and apparent stiffness showed consistent trends across subjects and movement frequencies. To validate the method, these values were used to predict the vertical force and the grip force applied to the handle for movement cycles that were not utilized in the reconstruction process. Analysis of the coupling between the four variables, two referent coordinates and two apparent stiffness values, revealed a single strong constraint reflecting the coupling between the grip force and vertical force. We view these data as providing experimental support for the idea of controlling natural, multi-muscle actions with shifts in a low-dimensional set of referent coordinates.
Lindemann, U; Farahmand, P; Klenk, J; Blatzonis, K; Becker, C
To investigate construct validity of linear encoder measurement of sit-to-stand performance power in older people by showing associations with relevant functional performance and physiological parameters. Cross-sectional study. Movement laboratory of a geriatric rehabilitation clinic. Eighty-eight community-dwelling, cognitively unimpaired older women (mean age 78 years). Sit-to-stand performance power and leg power were assessed using a linear encoder and the Nottingham Power Rig, respectively. Gait speed was measured on an instrumented walkway. Maximum quadriceps and hand grip strength were assessed using dynamometers. Mid-thigh muscle cross-sectional area of both legs was measured using magnetic resonance imaging. Associations of sit-to-stand performance power with power assessed by the Nottingham Power Rig, maximum gait speed and muscle cross-sectional area were r=0.646, r=0.536 and r=0.514, respectively. A linear regression model explained 50% of the variance in sit-to-stand performance power including muscle cross-sectional area (p=0.001), maximum gait speed (p=0.002), and power assessed by the Nottingham Power Rig (p=0.006). Construct validity of linear encoder measurement of sit-to-stand power was shown at functional level and morphological level for older women. This measure could be used in routine clinical practice as well as in large-scale studies. DRKS00003622. Copyright © 2015 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.
Md Anamul Islam
Full Text Available PURPOSE: This study aimed: i to examine the relationship between the magnitude of cross-talk in mechanomyographic (MMG signals generated by the extensor digitorum (ED, extensor carpi ulnaris (ECU, and flexor carpi ulnaris (FCU muscles with the sub-maximal to maximal isometric grip force, and with the anthropometric parameters of the forearm, and ii to quantify the distribution of the cross-talk in the MMG signal to determine if it appears due to the signal component of intramuscular pressure waves produced by the muscle fibers geometrical changes or due to the limb tremor. METHODS: Twenty, right-handed healthy men (mean ± SD: age = 26.7±3.83 y; height = 174.47±6.3 cm; mass = 72.79±14.36 kg performed isometric muscle actions in 20% increment from 20% to 100% of the maximum voluntary isometric contraction (MVIC. During each muscle action, MMG signals generated by each muscle were detected using three separate accelerometers. The peak cross-correlations were used to quantify the cross-talk between two muscles. RESULTS: The magnitude of cross-talk in the MMG signals among the muscle groups ranged from, R2(x, y = 2.45-62.28%. Linear regression analysis showed that the magnitude of cross-talk increased linearly (r2 = 0.857-0.90 with the levels of grip force for all the muscle groups. The amount of cross-talk showed weak positive and negative correlations (r2 = 0.016-0.216 with the circumference and length of the forearm respectively, between the muscles at 100% MVIC. The cross-talk values significantly differed among the MMG signals due to: limb tremor (MMGTF, slow firing motor unit fibers (MMGSF and fast firing motor unit fibers (MMGFF between the muscles at 100% MVIC (p<0.05, η2 = 0.47-0.80. SIGNIFICANCE: The results of this study may be used to improve our understanding of the mechanics of the forearm muscles during different levels of the grip force.
Kunelius, Amanda; Darzins, Susan; Cromie, Jean; Oakman, Jodi
(1) To develop a normative data set for hand strength and anthropometric dimensions in automotive trim line workers. (2) To examine the relationship between trim line worker demographics and hand strength. Work tasks inherent in the automobile manufacturing industry such as forceful gripping and pinching, place physical demands upon the hands and fingers. This places workers at risk of developing a musculoskeletal injury. To reduce the risk of injury it is necessary to apply user strength data in the design phase of hand intensive tasks in order to create a fit between the person and the task. Demographic variables, anthropometry and maximal grip and pinch strength were measured for one hundred and sixty-one trim line automotive workers. Their data were analyzed to examine the associations between the variables. Significant hand strength differences were found in relation to age, gender, hand dominance and anthropometry. The workers in this study had significantly lower strength values than previously used reference data. The disparity between the present study's strength data and that of Mathiowetz et al.  may be due to the different demographic pools from which the populations were drawn. A training effect appeared to exist in trim line workers which may have reduced the disparity in hand strength between the hands as the number of years worked on the line increased. Caution should be taken when applying international normative data sets to the design of hand tools/workstations, as global differences in hand strength are likely to exist.
Winges, Sara A.; Johnston, Jamie A.; Santello, Marco
To gain insight into the synergistic control of hand muscles, we have recently quantified the strength of correlated neural activity across motor units from extrinsic digit flexors during a five-digit object-hold task. We found stronger synchrony and coherence across motor units from thumb and index finger flexor muscle compartment than between the thumb flexor and other finger flexor muscle compartments. The present study of two-digit object hold was designed to determine the extent to which such distribution of common input among thumb-finger flexor muscle compartments, revealed by holding an object with five digits, is preserved when varying the functional role of a given digit pair. We recorded normal force exerted by the digits and electrical activity of single motor units from muscle flexor pollicis longus (FPL) and two compartments of the m. flexor digitorum profundus (FDP2 and FDP3; index and middle finger, respectively). Consistent with our previous results from five-digit grasping, synchrony and coherence across motor units from FPL-FDP2 was significantly stronger than in FPL-FDP3 during object hold with two digits [common input strength: 0.49 ± 0.02 and 0.35 ± 0.02 (means ± SE), respectively; peak coherence: 0.0054 and 0.0038, respectively]. This suggests that the distribution of common neural input is muscle-pair specific regardless of grip type. However, the strength of coherence, but not synchrony, was significantly stronger in two- versus five-digit object hold for both muscle combinations, suggesting the periodicity of common input is sensitive to grip type. PMID:16723414
Full Text Available Abstract Background Functional magnetic resonance imaging (fMRI has been widely used in studying human brain functions and neurorehabilitation. In order to develop complex and well-controlled fMRI paradigms, interfaces that can precisely control and measure output force and kinematics of the movements in human subjects are needed. Optimized state-of-the-art fMRI methods, combined with magnetic resonance (MR compatible robotic devices for rehabilitation, can assist therapists to quantify, monitor, and improve physical rehabilitation. To achieve this goal, robotic or mechatronic devices with actuators and sensors need to be introduced into an MR environment. The common standard mechanical parts can not be used in MR environment and MR compatibility has been a tough hurdle for device developers. Methods This paper presents the design, fabrication and preliminary testing of a novel, one degree of freedom, MR compatible, computer controlled, variable resistance hand device that may be used in brain MR imaging during hand grip rehabilitation. We named the device MR_CHIROD (Magnetic Resonance Compatible Smart Hand Interfaced Rehabilitation Device. A novel feature of the device is the use of Electro-Rheological Fluids (ERFs to achieve tunable and controllable resistive force generation. ERFs are fluids that experience dramatic changes in rheological properties, such as viscosity or yield stress, in the presence of an electric field. The device consists of four major subsystems: a an ERF based resistive element; b a gearbox; c two handles and d two sensors, one optical encoder and one force sensor, to measure the patient induced motion and force. The smart hand device is designed to resist up to 50% of the maximum level of gripping force of a human hand and be controlled in real time. Results Laboratory tests of the device indicate that it was able to meet its design objective to resist up to approximately 50% of the maximum handgrip force. The detailed
Schaffelhofer, Stefan; Agudelo-Toro, Andres; Scherberger, Hansjörg
Despite recent advances in decoding cortical activity for motor control, the development of hand prosthetics remains a major challenge. To reduce the complexity of such applications, higher cortical areas that also represent motor plans rather than just the individual movements might be advantageous. We investigated the decoding of many grip types using spiking activity from the anterior intraparietal (AIP), ventral premotor (F5), and primary motor (M1) cortices. Two rhesus monkeys were trained to grasp 50 objects in a delayed task while hand kinematics and spiking activity from six implanted electrode arrays (total of 192 electrodes) were recorded. Offline, we determined 20 grip types from the kinematic data and decoded these hand configurations and the grasped objects with a simple Bayesian classifier. When decoding from AIP, F5, and M1 combined, the mean accuracy was 50% (using planning activity) and 62% (during motor execution) for predicting the 50 objects (chance level, 2%) and substantially larger when predicting the 20 grip types (planning, 74%; execution, 86%; chance level, 5%). When decoding from individual arrays, objects and grip types could be predicted well during movement planning from AIP (medial array) and F5 (lateral array), whereas M1 predictions were poor. In contrast, predictions during movement execution were best from M1, whereas F5 performed only slightly worse. These results demonstrate for the first time that a large number of grip types can be decoded from higher cortical areas during movement preparation and execution, which could be relevant for future neuroprosthetic devices that decode motor plans.
CHEN Ying; ZHANG Wei; ZHAO Lei; LI Yan
GRIP domain proteins, locating to the trans-Golgi network, are thought to play an essential role in Golgi apparatus trafficking in yeast and animal cells. In the present study, AtGRIP cDNA was amplified by reverse transcriptase PCR from RNA isolated from Arabidopsis seedling. The GST fusion protein of AtGRIP was affinity-purified and its rabbit polyclonal antibody was obtained. Immuno-blotting with the purified anti-AtGRIP polyclonal antibody demonstrated that the molecular mass of AtGRIP protein is about 92 kD, and its expression is not tissue-specific in Arabidopsis. Immunoflourescent labeling and confocal microscopy revealed that the AtGRIP protein was co-localized with Golgi stacks in Arabidop-sis root cells. Immuno-gold labeling and electron microscopy observation showed that AtGRIP protein was mainly located to the membrane of the secretory vesicles of trans-Golgi network in Arabidopsis root cap cells. Taken together, these results indicate that the localization of GRIP domain proteins be-tween plants and animal cells are conserved. These results also suggest that the AtGRIP may be in-volved in regulating the formation or sorting of Golgi-associated vesicles in plant cells.
Lovchik, Christopher Scott (Inventor); Diftler, Myron A. (Inventor)
A compact robotic hand includes a palm housing, a wrist section, and a forearm section. The palm housing supports a plurality of fingers and one or more movable palm members that cooperate with the fingers to grasp and/or release an object. Each flexible finger comprises a plurality of hingedly connected segments, including a proximal segment pivotally connected to the palm housing. The proximal finger segment includes at least one groove defining first and second cam surfaces for engagement with a cable. A plurality of lead screw assemblies each carried by the palm housing are supplied with power from a flexible shaft rotated by an actuator and output linear motion to a cable move a finger. The cable is secured within a respective groove and enables each finger to move between an opened and closed position. A decoupling assembly pivotally connected to a proximal finger segment enables a cable connected thereto to control movement of an intermediate and distal finger segment independent of movement of the proximal finger segment. The dexterous robotic hand closely resembles the function of a human hand yet is light weight and capable of grasping both heavy and light objects with a high degree of precision.
Schaefer, Sydney Y.; DeJong, Stacey L.; Cherry, Kendra M.; Lang, Catherine E.
This study investigated whether grip type and/or task goal influenced reaching and grasping performance in post-stroke hemiparesis. Sixteen adults with post-stroke hemiparesis and twelve healthy adults reached to and grasped a cylindrical object using one of two grip types (3-finger or palmar) to achieve one of two task goals (hold or lift). Performance of the stroke group was characteristic of hemiparetic limb movement during reach-to-grasp, with more curved handpaths and slower velocities compared to the control group. These effects were present regardless of grip type or task goal. Other measures of reaching (reach time and reach velocity at object contact) and grasping (peak thumb-index finger aperture during the reach and peak grip force during the grasp) were differentially affected by grip type, task goal, or both, despite the presence of hemiparesis, providing new evidence that changes in motor patterns after stroke may occur to compensate for stroke-related motor impairment. PMID:22357103
Porrero, J L; Cano-Valderrama, O; Castillo, M J; Alonso, M T
Self-gripping meshes have been developed to avoid fixing sutures during inguinal hernia repair. Operative time is shorter when using a self-gripping mesh than with conventional Lichtenstein repair. However, these meshes can be difficult to handle because they fix to undesired structures. The aim of this report is to describe a new technique to avoid this problem. Inguinal hernia dissection is made as usual. Once dissection is finished, a Parietex ProGrip(®) (Covidien, Dublin, Ireland) flat sheet mesh is cut depending on the size needed. A small split is made between the lower and medium third of the mesh to mark where the split for the spermatic cord will be. Using this mark, the upper third of the mesh is folded over the medium third, hiding the microgrips that make this a self-gripping mesh. In this way, only the lower third of the mesh has the microgrips exposed and the mesh can be fixed to the pubic bone and inguinal ligament without fixation to undesired structures. Once the lower third of the mesh is fixed, the split for the spermatic cord is completed and the upper part of the mesh is passed below the spermatic cord. Then, the mesh is unfolded to expose the microgrips again and the medium and upper third of the mesh are descended to its final position. This proposed technique for inguinal hernia repair with self-gripping mesh makes the surgery easier, avoiding mesh fixation to undesired structures.
Mojtahedi, Keivan; Fu, Qiushi; Santello, Marco
The time course of grip force from object contact to onset of manipulation has been extensively studied to gain insight into the underlying control mechanisms. Of particular interest to the motor neuroscience and clinical communities is the phenomenon of bell-shaped grip force rate (GFR) that has been interpreted as indicative of feedforward force control. However, this feature has not been assessed quantitatively. Furthermore, the time course of grip force may contain additional features that could provide insight into sensorimotor control processes. In this study, we addressed these questions by validating and applying two computational approaches to extract features from GFR in humans: 1) fitting a Gaussian function to GFR and quantifying the goodness of the fit [root-mean-square error, (RMSE)]; and 2) continuous wavelet transform (CWT), where we assessed the correlation of the GFR signal with a Mexican Hat function. Experiment 1 consisted of a classic pseudorandomized presentation of object mass (light or heavy), where grip forces developed to lift a mass heavier than expected are known to exhibit corrective responses. For Experiment 2, we applied our two techniques to analyze grip force exerted for manipulating an inverted T-shaped object whose center of mass was changed across blocks of consecutive trials. For both experiments, subjects were asked to grasp the object at either predetermined or self-selected grasp locations ("constrained" and "unconstrained" task, respectively). Experiment 1 successfully validated the use of RMSE and CWT as they correctly distinguished trials with versus without force corrective responses. RMSE and CWT also revealed that grip force is characterized by more feedback-driven corrections when grasping at self-selected contact points. Future work will examine the application of our analytical approaches to a broader range of tasks, e.g., assessment of recovery of sensorimotor function following clinical intervention, interlimb
Bentley, Danielle Christine; Thomas, Scott Gordon
Handgrip (HG) exercise has been prescribed as a lifestyle intervention to successfully reduce resting blood pressure (BP) among heterogeneous groups of participants. Current HG protocols have limited accessibility due to complicated exercise prescriptions and sophisticated required equipment. Therefore, this research describes the design and evaluation of the maximal intermittent (MINT) HG exercise strategy, consisting of both a novel exercise protocol (32×5 seconds maximal grip squeezes separated by 5 seconds of rest between sets) and an original grip tool. This research was a multistep progressive design that included 51 postmenopausal women as participants in three separate research studies. Part 1 of this research focuses on the MINT exercise protocol. A literature-informed rationale for the design of the protocol is described. This includes exercise intensity, work-to-rest ratio, and total exercise duration with reference to the unique physiology (mechanoreflex and metaboreflex) of postmenopausal women. Subsequent experimental analyses of acute responses to the MINT protocol revealed that women produced 50% of their maximum grip force with moderate cardiovascular responses (increases of systolic BP: 41.6 mmHg, diastolic BP: 20.1 mmHg, heart rate: 35.1 bpm) that remained far below the thresholds of concern identified by the American College of Sports Medicine. Part 2 of this research describes the creation of a novel grip tool, beginning with a mixed-methods assessment of participant opinions regarding two distinct in-laboratory grip tools, leading to the creation of four prototype MINT tools. Structured focus groups revealed a strong preference for MINT prototype 1 for all tool design features, including color, shape, size, and foam grip. Collectively, the result of this multistep research is a novel HG exercise strategy with enhanced accessibility by being easy to understand and simple to execute. The long-term training effectiveness of MINT as an exercise
Ahmed Fathy Samhan. PhD PT
Full Text Available Background: Psoriatic arthritis is an entity of inflammatory joint disease associated with psoriasis. Purpose: The purpose of this study was to evaluate the efficacy of underwater interferential current therapy on hand function in psoriatic arthritis of both hands. Method: Thirty patients (18 females and 12 males had psoriatic arthritis of hands, aged 42 to 50 years with 45.77 ± 3.52 mean, were assigned randomly into two groups of equal number: study group received 20 minutes underwater interferential current for one month, 3 times per week (12 sessions and control group received placebo interferential current. Visual analogue scale for patient-reported pain, the Disability of Arm, Shoulder and Hand questionnaire score, and hand function (grip force in Pound of dominant hand were assessed pretreatment and post-treatment. Results: showed significant improvement in the 3 outcomes in study group (p 0.005. Visual analogue scale had a strong positive correlation (p < 0.001 with the disability score and a strong negative correlation (p < 0.001 with the grip force. Conclusion: Using underwater interferential current therapy in patient with psoriatic arthritis of hands was effective in improvement of hand function and quality of life.
Tsutsui, H; Murashima, Y; Honma, N; Akazawa, K
We developed a robot hand with three fingers and controlled them using underactuated control to obtain a more flexible grip. With underactuated control, we can flexibly operate an artificial robot hand and reduce the number of actuators. The robot fingers had three joints to imitate human fingers. One finger was driven by one wire and one servo motor for bending and by three torsion springs for extension. We also developed a soft tactile sensor having three pneumatic sensors and mounted it on front of each robot fingers. We obtained the following information from our experimental examinations of the robot hand. It adaptively grasped an object by underactuated control. The soft tactile sensor deftly touched an object, and the data showed the contact position with. By analyzing the data from tactile sensors, we obtained the rough information of the object's shape.
Lutsky, Kevin; Kim, Nayoung; Medina, Juana; Maltenfort, Mitchell; Beredjiklian, Pedro K
The goals of this study were to (1) assess how frequently patients present for evaluation of common hand disorders in relation to hand dominance and (2) evaluate the effect of hand dominance on function in patients with these conditions. The authors hypothesized that (1) the majority of patients who seek evaluation would have a condition that affects the dominant hand, and (2) disability scores would be worse if the dominant hand is involved. They retrospectively reviewed the records of consecutive patients who presented for treatment to their institution with unilateral symptoms of 5 common disorders of the hand: carpal tunnel syndrome (CTS), de Quervain's tenosynovitis (DEQ), lateral epicondylitis (LE), hand osteoarthritis (OA), and trigger finger (TF). The authors assessed the effect of diagnosis and hand dominance on Disabilities of the Arm, Shoulder and Hand (DASH) scores. The study group comprised 1029 patients (379 men and 650 women) with a mean age of 59.5 years. Ninety percent were right-hand dominant. The dominant and nondominant hands were affected with relatively equal frequency for CTS, DEQ, OA, and TF (range, 45%-53%). Patients with LE had a significantly higher incidence of dominant hand involvement. Men had lower DASH scores than women by an average of 7.9 points, and DASH scores were significantly but slightly higher for the overall group (3.2 points) when the dominant side was affected. Men with LE and women with TF and OA had significantly higher DASH scores when their dominant extremity was affected. Common hand disorders such as CTS, DEQ, OA, and TF affect the dominant and nondominant hands in roughly equivalent proportions, whereas LE is more common on the dominant side. Dominant hand involvement results in significantly worse DASH scores, although the magnitude of this is relatively small. Women have significantly higher DASH scores than men for the conditions evaluated. [Orthopedics. 2016; 39(3):e444-e448.].
With their 27 bones, 33 muscles and 22 joints, hands are the most complicated and at the same time the most useful parts of the body. Without them, we would not be able to grip things between our fingers, pick them up, turn them, lift them, hold them or handle them. Due to this very usefulness, however, they are more prone to injury than any other part of the body. This year, over 30% of CERN's industrial accidents involved hand injuries. Many of these accidents could have been avoided if the people concerned had worn suitable gloves or, quite simply, made proper use of tools adapted to the work they were doing. 1. Mechanically sustained injuries Most hand injuries are mechanically sustained. - Cuts and pricks often occur during the use or handling of sharp objects and tools. The Medical Service has treated many patients with cuts received when handling iron plates or when using cutters without taking adequate precautions. Such injuries range from superficial cuts to deep wounds with severed tendons or bl...
Ma, Zhou; Ben-Tzvi, Pinhas; Danoff, Jerome
This paper presents a hand rehabilitation learning system, the SAFE Glove, a device that can be utilized to enhance the rehabilitation of subjects with disabilities. This system is able to learn fingertip motion and force for grasping different objects and then record and analyze the common movements of hand function including grip and release patterns. The glove is then able to reproduce these movement patterns in playback fashion to assist a weakened hand to accomplish these movements, or to modulate the assistive level based on the user's or therapist's intent for the purpose of hand rehabilitation therapy. Preliminary data have been collected from healthy hands. To demonstrate the glove's ability to manipulate the hand, the glove has been fitted on a wooden hand and the grasping of various objects was performed. To further prove that hands can be safely driven by this haptic mechanism, force sensor readings placed between each finger and the mechanism are plotted. These experimental results demonstrate the potential of the proposed system in rehabilitation therapy.
Eisen, Andrew; Kuwabara, Satoshi
In amyotrophic lateral sclerosis (ALS), hand muscle wasting preferentially affects the 'thenar (lateral) hand', including the abductor pollicis brevis (APB) and first dorsal interosseous (FDI) muscles, with relative sparing of the hypothenar muscles (the abductor digiti minimi (ADM)). This peculiar pattern of dissociated atrophy of the intrinsic hand muscles is termed the 'split hand' and is rarely seen in diseases other than ALS. The muscles involved in the split hand are innervated through the same spinal segments (C8 and T1), and FDI and ADM, which are differentially affected, are both ulnar nerve innervated. The physiological mechanisms underlying the split hand in ALS are incompletely understood but both cortical and spinal/peripheral mechanisms are probably involved. Motor potentials evoked by magnetic stimulation are significantly smaller when recorded from the thenar complex, compared with the hypothenar muscles, supporting a cortical mechanism. But peripheral axonal excitability studies have suggested that APB/FDI motor axons have more prominent persistent sodium currents than ADM axons, leading to higher axonal excitability and thereby more ready degeneration. Pincer or precision grip is vital to human hand function, and frequent use of thenar complex muscles may lead to greater oxidative stress and metabolic demands at both upper and lower motoneurons innervating the APB and FDI. The split hand is a useful diagnostic sign in early ALS, and recent objective studies indicate that the sign has a high degree of specificity.
Diaz Millan, Sebastian; Rugbeño S.A.S; Aguilar Castro, Yesid; Escuela de Ingeniería de Materiales, Universidad del Valle, Cali, Colombia; Casanova García, Gonzalo Fernando; Escuela de Ingeniería Mecánica,Universidad del Valle, Cali, Colombia
Wear on sugar cane rolls is an expensive maintenance problem for the sugar cane industry. Wear produces loss of sucrose extraction and loss of grip of the roll on the bagasse. This paper presents the evaluation of wear and loss of grip of hypoeutectic and hypereutectic high chromium welding deposits applied on ASTM A-36 steel and gray cast iron. A modified ASTM G-65 standard test was used. Wear was produced by the abrasive action of wet bagasse with three levels of mineral extraneous matter. ...
Nuclear science is an important topic in terms of its application to power generation, medical diagnostics and treatment, and national defense. Unfortunately, the subatomic domain is far removed from daily experience, and few learning aids are available to teachers. What follows describes a low-tech, hands-on method to teach important concepts in…
Nuclear science is an important topic in terms of its application to power generation, medical diagnostics and treatment, and national defense. Unfortunately, the subatomic domain is far removed from daily experience, and few learning aids are available to teachers. What follows describes a low-tech, hands-on method to teach important concepts in…
Meireles, Sandra Mara; Jones, Anamaria; Jennings, Fabio; Suda, Alina Lica; Parizotto, Nivaldo Antônio; Natour, Jamil
Assess the effectiveness of low-level laser therapy on pain reduction and improvement in function in the hands of patients with rheumatoid arthritis. A randomized double-blind controlled trial was carried out on 82 patients with rheumatoid arthritis. The experimental group was submitted to the application of laser therapy, whereas the control group received a placebo laser. Aluminum gallium arsenide laser was used, at a wavelength of 785 nm, dose of 3 J/cm(2) and mean power of 70 mW. The groups were homogenous at the beginning of the study with regard to the main variables (p > 0.05). There were no statistically significant differences between groups in most of the measurements taken at the end of the intervention including the primary variables; the following variables were the exceptions: favoring the experimental group-inflammation of the interphalangeal joint of the right thumb (p = 0.012) and perimetry of the interphalangeal joint of the left thumb (p = 0.013); and favoring the control group-flexion of the proximal interphalangeal joint of the right fifth finger (p = 0.021), perimetry of the third proximal interphalangeal joint of the right hand (p = 0.044), grip strength in the left hand (p = 0.010), and the work domain of the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire (p = 0.010). We conclude that low-level aluminum gallium arsenide laser therapy is not effective at the wavelength, dosage, and power studied for the treatment of hands among patients with rheumatoid arthritis.
Full Text Available ... children, parents, and public health professionals. More > Hand Hygiene Saves Lives (5:10) Recommend on Facebook Tweet Share Compartir Hand Hygiene Saves Lives Hand Hygiene Saves Lives Transcript [28 KB, 2 pages] High ...
Full Text Available ... including, children, parents, and public health professionals. More > Hand Hygiene Saves Lives (5:10) Recommend on Facebook Tweet Share Compartir Hand Hygiene Saves Lives Hand Hygiene Saves Lives Transcript [28 KB, 2 pages] High ...
... including, children, parents, and public health professionals. More > Hand Hygiene Saves Lives (5:10) Recommend on Facebook Tweet Share Compartir Hand Hygiene Saves Lives Hand Hygiene Saves Lives Transcript [28 KB, 2 pages] High ...
Goldberg, Judith L
Performing proper hand hygiene and surgical hand antisepsis is essential to reducing the rates of health care-associated infections, including surgical site infections. The updated AORN "Guideline for hand hygiene" provides guidance on hand hygiene and surgical hand antisepsis, the wearing of fingernail polish and artificial nails, proper skin care to prevent dermatitis, the wearing of jewelry, hand hygiene product selection, and quality assurance and performance improvement considerations. This article focuses on key points of the guideline to help perioperative personnel make informed decisions about hand hygiene and surgical hand antisepsis. The key points address the necessity of keeping fingernails and skin healthy, not wearing jewelry on the hands or wrists in the perioperative area, properly performing hand hygiene and surgical hand antisepsis, and involving patients and visitors in hand hygiene initiatives. Perioperative RNs should review the complete guideline for additional information and for guidance when writing and updating policies and procedures.
corn ears from top to bottom, and this way does not have the problem of hurting corn ears, so we break through the traditional way and use a new way to design this device. The working principle of this device is that power is provided by the speed regulating motor. After driving sprocket drives the power, the left driving wheel for breaking ears rotates clockwise and the right driving wheel for breaking ears rotates counterclockwise. The breaking ear hands move from the top to the bottom in the breaking ears space, which does not allow the corn ears to cross the space, and when the hands touch the corn ear, they will pick up it. Many tests have already been done to prove the feasibility of the device. First we do the single-factor tests, and we test the force required by picking up corn ears in the traditional way and the bionic way respectively under the static and dynamic condition. In traditional way we fix the corn on the equipment along the direction of plant growth, and in bionic way we fix the corn on the equipment against the direction of plant growth; under static condition we provide tension slowly, under dynamic condition we provide tension suddenly, we analyze the data and get the relationship between them; and then we do the power consumption test that is used by bionic device of breaking corn ears. We do the test in laboratory in which the device can’t move but corn plants move; we design a device system and fix the corn plants in the track that can be driven by motor, and the traveling speed is set as 1.0 m/s. The speed of breaking corn ears hand is different, and the ko camera is used to record the test process and the power meter is used to record the power consumption. Finally we get the relationship between the speed of breaking corn ears hand and the pure power consumption. Tests show that the force required in the bionic way is significantly reduced, which is only one tenth of the traditional way, and this is decided by physiological
Frederiksen, Henrik; Hjelmborg, Jacob; Mortensen, Jakob
with increasing age. Estimates were obtained by using full-information methods from large population-representative studies. Equations of expected grip strength, as well as tables with sex-, age-, and height-stratified reference data, provide an opportunity to include grip-strength measurement in clinical care...
Samuel, Dinesh; Rowe, Philip
Grip strength is a predictor of health outcomes but with differing rates of age-related decline in muscle strength, it is unclear whether handgrip is a reliable indicator of lower limb moments. This study investigated the relationship between grip strength and lower extremity moments in community-dwelling older adults. Eighty-two healthy volunteers aged 60-82 years (mean age 73.2 years) performed maximal voluntary contractions of knee and hip extensors and flexors at three positions and at neutral position for hip abductors and adductors using a custom-built dynamometer. Grip strength was measured using an electronic Jamar dynamometer. The relative reduction in muscle strength of 80s age category compared to 60-year-olds ranged from 14% for grip strength to 27% for hip abductors. Peak torque of flexors and extensors of the knee and hip joints were significantly correlated with grip strength and Pearson's correlation coefficients ranged from 0.56 to 0.78 with the highest correlations observed between knee moments and grip strength. "Good" correlation was found but only 31-60% of the variation in grip strength could be related to changes in joint torques. Hence the assumption that grip strength is an indicator of strength in the lower limb would seem unjustified in the healthy older adult.
Zwijsen, S.A.; Bosmans, J.E.; Gerritsen, D.L.; Pot, A.M.; Hertogh, C.M.; Smalbrugge, M.
OBJECTIVE: The objective of the study was to evaluate the cost-effectiveness of implementing the Grip on Challenging Behaviour care programme (GRIP) on dementia special care units in comparison with usual care. METHODS: A stepped wedge design was used. Challenging behaviour and quality of life were
Gatouillat, Arthur; Dumortier, Antoine; Perera, Subashan; Badr, Youakim; Gehin, Claudine; Sejdić, Ervin
Writing is a complex fine and trained motor skill, involving complex biomechanical and cognitive processes. In this paper, we propose the study of writing kinetics using three angles: the pen-tip normal force, the total grip force signal and eventually writing quality assessment. In order to collect writing kinetics data, we designed a sensor collecting these characteristics simultaneously. Ten healthy right-handed adults were recruited and were asked to perform four tasks: first, they were instructed to draw circles at a speed they considered comfortable; they then were instructed to draw circles at a speed they regarded as fast; afterwards, they repeated the comfortable task compelled to follow the rhythm of a metronome; and eventually they performed the fast task under the same timing constraints. Statistical differences between the tasks were computed, and while pen-tip normal force and total grip force signal were not impacted by the changes introduced in each task, writing quality features were affected by both the speed changes and timing constraint changes. This verifies the already-studied speed-accuracy trade-off and suggest the existence of a timing constraints-accuracy trade-off. Copyright © 2017 Elsevier Ltd. All rights reserved.
Takahashi, Jumpei; Nishiyama, Toru; Matsushima, Yoshimasa
[Purpose] Grip strength is used as an indicator of overall body muscular strength. However, most studies on grip strength have been performed in healthy people, and no study has evaluated it in the unaffected side of patients with hemiparetic stroke. The purpose of this study was to determine if grip strength on the unaffected side of patients with hemiparetic stroke correlates with the strength of other ipsilateral musculature. [Subjects and Methods] The maximal strengths of the muscles on the unaffected side of 31 patients with hemiparetic stroke were measured, and correlation coefficients were calculated. [Results] The results revealed significant positive correlations between grip strength on the unaffected side and the strength of the other ipsilateral muscle groups, with relatively high correlations being observed for the upper extremity muscle groups. [Conclusion] This suggests that grip strength on the unaffected side of patients with hemiparetic stroke can be used as a simple way to estimate overall strength on that side.
Savva, Christos; Giakas, Giannis; Efstathiou, Michalis; Karagiannis, Christos
The purpose of this study was to evaluate the test-retest reliability of handgrip strength measurement using a hydraulic hand dynamometer in patients with cervical radiculopathy (CR). A convenience sample of 19 participants (14 men and 5 women; mean ± SD age, 50.5 ± 12 years) with CR was measured using a Jamar hydraulic hand dynamometer by the same rater on 2 different testing sessions with an interval of 7 days between sessions. Data collection procedures followed standardized grip strength testing guidelines established by the American Society of Hand Therapists. During the repeated measures, patients were advised to rest their upper limb in the standardized arm position and encouraged to exert 3 maximum gripping efforts. The mean value of the 3 efforts (measured in kilogram force [Kgf]) was used for data analysis. The intraclass correlation coefficient, SEM, and the Bland-Altman plot were used to estimate test-retest reliability and measurement precision. Grip strength measurement in CR demonstrated an intraclass correlation coefficient of 0.976, suggesting excellent test-retest reliability. The small SEM in both testing sessions (SEM1, 2.41 Kgf; SEM2, 2.51 Kgf) as well as the narrow width of the 95% limits of agreements (95% limits of agreement, -4.9 to 4.4 Kgf) in the Bland-Altman plot reflected precise measurements of grip strength in both occasions. Excellent test-retest reliability for grip strength measurement was measured in patients with CR, demonstrating that a hydraulic hand dynamometer could be used as an outcome measure for these patients. Copyright © 2014 National University of Health Sciences. Published by Mosby, Inc. All rights reserved.
Braithwaite, Steven P; Xia, Houhui; Malenka, Robert C
alpha-Amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor (AMPAR) stability and movement at synapses are important factors controlling synaptic strength. Here, we study the roles of proteins [N-ethylmaleimide-sensitive fusion protein (NSF), glutamate receptor AMPAR binding protein (ABP)-interacting protein (GRIP)/(ABP), and protein interacting with C-kinase-1 (PICK1) that interact with the GluR2 subunit in the control of the surface expression and cycling of AMPARs. Epitope-tagged GluR2 formed functional receptors that exhibited targeting to synaptic sites. Constructs in which binding to NSF, PDZ proteins (GRIP/ABP and PICK1), or GRIP/ABP alone was eliminated each exhibited normal surface targeting and constitutive cycling. The lack of NSF binding, however, resulted in receptors that were endocytosed to a greater extent than wild-type receptors in response to application of AMPA or N-methyl-d-aspartate (NMDA). Conversely, the behavior of the GluR2 mutants incapable of binding to GRIP/ABP suggests that these PDZ proteins play a role in the stabilization of an intracellular pool of AMPARs that have been internalized on stimulation, thus inhibiting their recycling to the synaptic membrane. These results provide further evidence for distinct functional roles of GluR2-interacting proteins in AMPAR trafficking.
van Nuenen, Bart F L; Kuhtz-Buschbeck, Johann; Schulz, Christian
). An additional pre-cue (S1) correctly predicted the weight in 75% of the trials. Participants were asked to use this prior information to prepare for the lift. In the sham condition, grip force showed a consistent undershoot, if the S1 incorrectly prompted the preparation of a light lift. Likewise, an S1...
Mortensen, Ditte Hvas
This poster abstract presents the first part of a study concerning the use of information about gaze, grip and gesture to create non-command interaction. The experiment reported here seeks to establish the occurrence of patterns in nonverbal communication, which may be used in an activity aware...
Law, Sui-Heung; Lo, Sing Kai; Chow, Susanna; Cheing, Gladys L.Y.
Excessive grip force (GF) is often found in children with developmental coordination disorder (DCD). However, their GF control may vary when task constraints are imposed upon their motor performance. This study aimed to investigate how their GF control changes in response to task demands, and to examine their tactile sensitivity. Twenty-one…
Mishra Prashant Akhilesh
Full Text Available Background and Objective: Therapeutic eccentric exercise may provide both a structural and functional benefit during tendinopathy rehabilitation. The objective is to find the effect of eccentric exercises on improvement of pain and grip strength for subjects with Medial Epicondylitis. Method: Pre to post test experimental study design randomized thirty subjects with medial epicondylitis, 15 each into Group A and Group B. Group B subjects were treated with conventional therapy and Eccentric exercises. Group A subjects were treated with conventional therapy. Results: When means of post intervention were compared using Independent ‘t’ between groups there was no statistically significant difference in improvements obtained in VAS scores and grip strength. There was a statistically significant change in means of VAS score and Grip strength when means were analyzed by using Paired‘t’ test and Wilcoxon signed rank test within the groups with positive percentage of change. Conclusion: It is concluded that four weeks of Eccentric Exercise Programme combined with conventional therapy shown significant effect on improving pain and Grip strength, however the improvement obtained has no difference when compared with control conventional treatment for Subjects with Medial Epicondylitis.
Lindemann, Oliver; Abolafia, Juan A.; Girardi, Giovanna; Bekkering, Harold
To investigate the functional connection between numerical cognition and action planning, the authors required participants to perform different grasping responses depending on the parity status of Arabic digits. The results show that precision grip actions were initiated faster in response to small
Frimand Rönnow, Carl-Fredrik; Jeppsson, Bengt; Thorlacius, Henrik
Purpose The Frimand needle holder (FNH) was developed to facilitate palm grip suturing. In the present study, we wanted to examine the impact of the FNH compared with a conventional Hegar-styled needle holder (HSNH) on suture time and surgical stress. Methods Thirty-two surgeons were enrolled and they performed sets of 3 continuous sutures on a polyurethane pad with premarked insert and exit points and the time for suturing was measured. Surgical stress was quantified by having the surgeons to perform 10 release maneuvers with the FNH and the HSNH on a needle attached to a scale. The scale sent 5 values per second to a computer. The first measurement of each series was regarded as the starting weight and all subsequent measurements were either regarded as neutral, pressure or traction. The sum of these measurements represented total surgical stress. Results We found that all surgeons reduced their median suturing time by 16% when using FNH for palm grip suturing with no difference between junior and senior surgeons. Moreover, it was observed that FNH decreased median surgical stress by 62% for all surgeons performing palm grip suturing compared with a conventional HSNH. Conclusion We conclude that the FNH reduces suture time and surgical stress compared with HSNH when performing palm grip suturing. These findings warrant studies in surgical patients in order to evaluate the potential clinical impact of FNH.
Duncan, Nicole; Shih, A Y; Hurford, G J; Bain, H M; Amman, M; Mochizuki, B A; Hoberman, J; Olson, J; Maruca, B A; Godbole, N M; Smith, D M; Sample, J; Kelley, N A; Zoglauer, A; Caspi, A; Kaufmann, P; Boggs, S; Lin, R P
The Gamma-Ray Imager/Polarimeter for Solar flares (GRIPS) is a balloon-borne telescope designed to study solar-flare particle acceleration and transport. We describe GRIPS's first Antarctic long-duration flight in Jan 2016 and report preliminary calibration and science results. Electron and ion dynamics, particle abundances and the ambient plasma conditions in solar flares can be understood by examining hard X-ray (HXR) and gamma-ray emission (20 keV to 10 MeV) with enhanced imaging, spectroscopy and polarimetry. GRIPS is specifically designed to answer questions including: What causes the spatial separation between energetic electrons producing HXRs and energetic ions producing gamma-ray lines? How anisotropic are the relativistic electrons, and why can they dominate in the corona? How do the compositions of accelerated and ambient material vary with space and time, and why? GRIPS's key technological improvements over the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) include 3D position-sensi...
Yu, Junhong; Rawtaer, Iris; Mahendran, Rathi; Kua, Ee-Heok; Feng, Lei
Despite the abundance of studies on asymmetries in manual laterality, a marker for atypical brain lateralization in depression and anxiety, findings in this area are mixed. Traditionally, research have looked at individual differences in depression and anxiety as a function of the direction of asymmetry. However, recent research has emphasized on studying the degree of asymmetry in addition to its direction. To these ends, the present study aims to unravel the associations between the degree and direction of manual lateralization, and depression/anxiety. Cognitively healthy elderlies (N = 326, 91 males, Mage = 68) were administered grip strength assessments on both hands and self-report measures of depression and anxiety. Partial correlation analyses controlling for age, education and sex revealed significant positive associations between degree of lateralization and anxiety in the overall sample and among right-dominant participants, as well as a significant positive relationship between degree of lateralization and depression among right-dominant participants. None of the correlations involving the direction of lateralization yielded significance, neither was there significant differences between left- and right-dominant participants on depression and anxiety scores. These findings suggest that the degree of manual lateralization, but not direction, is related to depression and anxiety at least among right-dominant individuals.
İnal, Esra Erkol; Demİrcİ, kadİr; Çetİntürk, Azİze; Akgönül, Mehmet; Savaş, Serpİl
In this study we investigated the flexor pollicis longus (FPL) tendon and median nerve in smartphone users by ultrasonography to assess the effects of smartphone addiction on the clinical and functional status of the hands. One hundred two students were divided into 3 groups: non-users, and high or low smartphone users. Smartphone Addiction Scale (SAS) scores and grip and pinch strengths were recorded. Pain in thumb movement and rest and hand function were evaluated on the visual analog scale (VAS) and the Duruöz Hand Index (DHI), respectively. The cross-sectional areas (CSAs) of the median nerve and the FPL tendon were calculated bilaterally using ultrasonography. Significantly higher median nerve CSAs were observed in the dominant hands of the high smartphone users than in the non-dominant hands (PSmartphone overuse enlarges the median nerve, causes pain in the thumb, and decreases pinch strength and hand functions. © 2015 Wiley Periodicals, Inc.
Smit, G.; Plettenburg, D.H.
The Delft Institute of Prosthetics and Orthotics has started a research program to develop an improved voluntary closing, body-powered hand prosthesis. Five commercially available voluntary closing terminal devices were mechanically tested: three hands [Hosmer APRL VC hand, Hosmer Soft VC Male hand,
Franck, Johan Anton; Smeets, Rob Johannes Elise Marie; Seelen, Henk Alexander Maria
Arm-hand rehabilitation programs applied in stroke rehabilitation frequently target specific populations and thus are less applicable in heterogeneous patient populations. Besides, changes in arm-hand function (AHF) and arm-hand skill performance (AHSP) during and after a specific and well-described rehabilitation treatment are often not well evaluated. This single-armed prospective cohort study featured three subgroups of stroke patients with either a severely, moderately or mildly impaired AHF. Rehabilitation treatment consisted of a Concise_Arm_and_hand_ Rehabilitation_Approach_in_Stroke (CARAS). Measurements at function and activity level were performed at admission, clinical discharge, 3, 6, 9 and 12 months after clinical discharge. Eighty-nine stroke patients (M/F:63/23; mean age:57.6yr (+/-10.6); post-stroke time:29.8 days (+/-20.1)) participated. All patients improved on AHF and arm-hand capacity during and after rehabilitation, except on grip strength in the severely affected subgroup. Largest gains occurred in patients with a moderately affected AHF. As to self-perceived AHSP, on average, all subgroups improved over time. A small percentage of patients declined regarding self-perceived AHSP post-rehabilitation. A majority of stroke patients across the whole arm-hand impairment severity spectrum significantly improved on AHF, arm-hand capacity and self-perceived AHSP. These were maintained up to one year post-rehabilitation. Results may serve as a control condition in future studies.
The measurement of hand grip strength has gained attention as a simple, non-invasive marker of muscle strength of upper extremities, and more and more researches show that it well suitable for clinical use. This review outlines the prognostic relevance of grip strength in various clinical and epidemiologic settings and describes the relationship between grip strength and fitness for older adults.%握力作为一项简单、无创的上肢肌肉力量测试指标而为人们所关注，越来越多的研究显示握力测试应用于临床也是适合的。这篇文献综述概述了在临床医学和流行病学领域里老年人握力的关联与预测，同时也描述了握力与体适能之间的关系。
Erol, Kemal; Gok, Kevser; Cengiz, Gizem; Ozgocmen, Salih
Hand joints are the main target in rheumatoid arthritis (RA) and hand involvement in terms of thickening of the skin and contractures are also well known in systemic sclerosis (SSc). Assessment of hand function in SSc is generally an overlooked entity with respect to RA. Therefore the aim of this study was to compare hand functions and potential influence of functional loss on patients' overall physical functions, health-related quality of life (HRQoL) and psychological status in RA and SSc. Age- and gender-matched adult patients with SSc and RA were consecutively recruited. Patients' hand functions were evaluated by using the Duruöz Hand Index (DHI), and hand span and hand grip strength were measured. Patients were evaluated for disease-specific and generic outcome measures including disease activity parameters and HRQoL measures. Fifty patients (44 female, six male) with SSc and 51 (45 female, six male) with RA were included. Despite similar functioning and HRQoL, patients with RA had higher visual analog scale-pain and body mass index. In both groups DHI revealed similar functional loss and correlated with various measurements related to HRQoL. In SSc, hand span, grip strength and modified Rodnan skin score had major influences on hand functions. Assessment of hand function is an important component in the clinical evaluation of patients with RA and SSc. Loss of hand functions is an important feature contributing negatively to the overall physical status and HRQoL in patients with SSc and may be more frequent and important than expected. © 2017 Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd.
Ellegaard, Karen; Torp-Pedersen, Søren; Lund, Hans
In 90% of patients with rheumatoid arthritis (RA), the joints of the hand are affected. Studies of grip strength training have not indicated a negative effect on disease activity after training. Introduction of ultrasound Doppler (USD) to measure increased blood flow induced by inflammation has...
Li, Xiaoyan; He, Wensheng; Li, Charles; Wang, Ying-Chih; Slavens, Brooke A; Zhou, Ping
This study investigated the effect of handedness on motor unit number index (MUNIX). Maximal hand strength, compound muscle action potential (CMAP) and voluntary surface electromyography (EMG) signals were measured bilaterally for the first dorsal interosseous (FDI) and thenar muscles in 24 right-handed and 2 left-handed healthy subjects. Mean (±standard error) grip and pinch forces in the dominant hand were 43.99 ± 2.36 kg and 9.36 ± 0.52 kg respectively, significantly larger than those in the non-dominant hand (grip: 41.37 ± 2.29 kg, p muscles. In addition, there was a lack of correlation between the strength and myoelectric parameters in regression analysis. However, strong correlations were observed between dominant and non-dominant hand muscles in both strength and myoelectric measures. Our results indicate that the population of motor units or spinal motor neurons as estimated from MUNIX may not be associated with handedness. Such findings help understand and interpret the MUNIX during its application for clinical or laboratory investigations.
Mohammad Rashed Iqbal Faruque
Full Text Available This paper proposes the effect of the hand-hold position on the electromagnetic (EM wave interaction of a candy bar type and clamshell type cellular handset and a human head and hand is investigated. The human hand influences the performance of terminal antennas, and it is the main cause for absorption and detuning. In spite of its importance in mobile-phone design and validation processes, it is still complicated to take it into account because a lack of knowledge in the area. In this paper, a rigorous investigation methodology is described for the study of candy bar, and clam shell mobile phone CAD model is used to numerically investigate the effect of hand phantom of mobile phone antenna radiation performance. The simulation results show that mobile phone grip styles of the hand phantom material properties, wrist and length, and hand phantom sizes and different positions is the important parameter to antenna performance. The grip style has direct implications in the definition of phantom head. The preference of the handset with respect to the side of the user’s head depends on the mobile phone form factor and size. The results established high reliability and suitability for providing decision rationale for the design of complex high-end multi-band mobile phones.
Omar, Mohammed T Ahmed; Hassan, Ahmed A
Thermal injury of the hand is characterized by disfigurement and deformity with marked problems because the patient is no longer able to perform the daily living activities and function at school or work. Early excision and grafting (E&G) were introduced to decrease hospital stay, hospital cost, and septic complications and to eliminate burn toxins. In this study, E&G was compared with delayed skin grafting in deep hand burns. 40 patients with deep second- and third- degree hand burns with average burn size less than 30% total body surface area (TBSA) were randomly divided into E&G group and delayed grafting group. All hands in both groups were subjected to pre and post operative program of physiotherapy. Measurement of total active motion (TAM) of each digit and grip strength was recorded pre and post operative. Hand function using Jebsen-Taylor hand function test (JTHFT) was recorded three months after operation in both groups. There were statistically significant differences in both groups regarding to TAM, hand grip strength and Jebsen-Taylor hand function test favoring the E&G group. The study concluded that early excision and skin grafting with physiotherapy gave better results than delayed grafting in terms of preservation of hand function and shortened hospital stay. Copyright © 2010 Elsevier Ltd and ISBI. All rights reserved.
Objective To study the positive association between hand grip strength and bone mineral density in postmenopausal women.We conducted a screening program for osteoporosis in a large cohort of postmenopausal women to investigate the relation among hand grip strength,other nutritional parameters and bone density.Methods This investigation involved 973 volunteers from March 2012 to March 2013 at Tianjin Hongqiao Hospital.Bone mineral density,hand grip strength measurement,body mass index and T score were analyzed.Results Univariate analysis showed that hand grip strength measurement,body mass index and T score were correlated (Pearson correlation coefficient were 0.201,0.115,P =0.001,0.009) ; age and T score were negatively correlated(Pearson correlation coefficient were-0.358,P =0.001).Incidence of osteoporosis was 19.7％ (192/973).Conclusion Both body mass index and handgrip strength are strongly correlated to bone mineral density.%目的 探讨绝经后女性握力和体重指数与骨密度之间的相关性.方法 收集2012年3月至2013年3月在天津市红桥医院检查治疗973名女性志愿者,所有志愿者均接受足跟部骨密度测量(T指数)、握力测试和体重指数测量并进行相关性分析.结果 在单变量分析中,握力和体重指数与T指数相关(Pearson相关系数分别为0.201、0.115,P=0.001、0.009),年龄与T指数呈负相关(Pearson相关系数为-0.358,P=0.001).骨质疏松发病率18.7％(182/973).有骨质疏松和无骨质疏松绝经年龄、握力比较[绝经年龄(48±6)岁比(49±5)岁,P=0.020;握力(23±6)kg比(24±6) kg,P=0.001].结论 体重指数和握力二者均与骨密度密切相关,二者可作为预示骨疾病的关键因子.
Duncan, Nicole; Saint-Hilaire, P.; Shih, A. Y.; Hurford, G. J.; Bain, H. M.; Amman, M.; Mochizuki, B. A.; Hoberman, J.; Olson, J.; Maruca, B. A.; Godbole, N. M.; Smith, D. M.; Sample, J.; Kelley, N. A.; Zoglauer, A.; Caspi, A.; Kaufmann, P.; Boggs, S.; Lin, R. P.
The Gamma-Ray Imager/Polarimeter for Solar flares (GRIPS) instrument is a balloon-borne telescope designed to study solar- are particle acceleration and transport. We describe GRIPS's first Antarctic long-duration flight in January 2016 and report preliminary calibration and science results. Electron and ion dynamics, particle abundances and the ambient plasma conditions in solar flares can be understood by examining hard X-ray (HXR) and gamma-ray emission (20 keV to 10 MeV). Enhanced imaging, spectroscopy and polarimetry of are emissions in this energy range are needed to study particle acceleration and transport questions. The GRIPS instrument is specifically designed to answer questions including: What causes the spatial separation between energetic electrons producing hard X-rays and energetic ions producing gamma-ray lines? How anisotropic are the relativistic electrons, and why can they dominate in the corona? How do the compositions of accelerated and ambient material vary with space and time, and why? GRIPS's key technological improvements over the current solar state of the art at HXR/gamma-ray energies, the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI), include 3D position-sensitive germanium detectors (3D-GeDs) and a single-grid modulation collimator, the multi-pitch rotating modulator (MPRM). The 3D-GeDs have spectral FWHM resolution of a few hundred keV and spatial resolution 150 keV, the energy deposition sites can be tracked, providing polarization measurements as well as enhanced background reduction through Compton imaging. Each of GRIPS's detectors has 298 electrode strips read out with ASIC/FPGA electronics. In GRIPS's energy range, indirect imaging methods provide higher resolution than focusing optics or Compton imaging techniques. The MPRM gridimaging system has a single-grid design which provides twice the throughput of a bi-grid imaging system like RHESSI. The grid is composed of 2.5 cm deep tungsten-copper slats, and quasi
Full Text Available Danielle Christine Bentley, Scott Gordon Thomas Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada Abstract: Handgrip (HG exercise has been prescribed as a lifestyle intervention to successfully reduce resting blood pressure (BP among heterogeneous groups of participants. Current HG protocols have limited accessibility due to complicated exercise prescriptions and sophisticated required equipment. Therefore, this research describes the design and evaluation of the maximal intermittent (MINT HG exercise strategy, consisting of both a novel exercise protocol (32×5 seconds maximal grip squeezes separated by 5 seconds of rest between sets and an original grip tool. This research was a multistep progressive design that included 51 postmenopausal women as participants in three separate research studies. Part 1 of this research focuses on the MINT exercise protocol. A literature-informed rationale for the design of the protocol is described. This includes exercise intensity, work-to-rest ratio, and total exercise duration with reference to the unique physiology (mechanoreflex and metaboreflex of postmenopausal women. Subsequent experimental analyses of acute responses to the MINT protocol revealed that women produced 50% of their maximum grip force with moderate cardiovascular responses (increases of systolic BP: 41.6 mmHg, diastolic BP: 20.1 mmHg, heart rate: 35.1 bpm that remained far below the thresholds of concern identified by the American College of Sports Medicine. Part 2 of this research describes the creation of a novel grip tool, beginning with a mixed-methods assessment of participant opinions regarding two distinct in-laboratory grip tools, leading to the creation of four prototype MINT tools. Structured focus groups revealed a strong preference for MINT prototype 1 for all tool design features, including color, shape, size, and foam grip. Collectively, the result of this multistep
Vesia, Michael; Barnett-Cowan, Michael; Elahi, Behzad; Jegatheeswaran, Gaayathiri; Isayama, Reina; Neva, Jason L; Davare, Marco; Staines, W Richard; Culham, Jody C; Chen, Robert
According to one influential view, two specialized parieto-frontal circuits control prehension: a dorsomedial stream for hand transport during reaching and a dorsolateral stream for preshaping the fingers during grasping. However, recent evidence argues that an area within the dorsomedial stream-macaque area V6A and, its putative human homolog, superior parietal occipital cortex (SPOC) - encodes both hand transport and grip formation. We tested whether planning varied hand actions modulates functional connectivity between left SPOC and ipsilateral primary motor cortex (M1) using a dual-site, paired-pulse transcranial magnetic stimulation paradigm with two coils (dsTMS). Participants performed three different hand actions to a target object comprising a small cylinder atop a larger cylinder. These actions were: reaching-to-grasp the top (GT) using a precision grip, reaching-to-grasp the bottom (GB) using a whole-hand grip, or reaching-to-touch (Touch) the side of the target object without forming a grip. Motor-evoked potentials (MEPs) from TMS to M1, with or without preceding TMS to SPOC, were recorded from first dorsal interosseous (FDI) and abductor digiti minimi (ADM) hand muscles in two experiments that varied timing parameters (the stimulus onset asynchrony, SOA, between the 'GO' cue and stimulation and interpulse interval, IPI, between SPOC and M1 stimulation). We found that preparatory response amplitudes in the SPOC-M1 circuit of different hand muscles were selectively modulated early in the motor plan for different types of grasps. First, based on SPOC-M1 interactions, across two experiments, the role of the ADM was facilitated during a whole-hand grasp of a large object (GB) relative to other conditions under certain timing parameters (SOA = 150 msec; IPI = 6 msec). Second, the role of the FDI was facilitated during hand action planning compared to rest. These findings suggest that the human dorsomedial parieto-motor stream plays a causal role in
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.org Arthritis of the Hand Page ( 1 ) The hand and wrist have multiple small joints that work together to ... a shoelace. When the joints are aﬀected by arthritis, activities of daily living can be diﬃcult. Arthritis ...
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Jensen, L.; Stephan, J. [NAISS GmbH, Berlin (Germany)
The rising requirements in efficiency and quality lead to products of in addition integration and functionality with ever smaller components. In addition new materials with improved characteristics are used e.g. GRP components plastics. Due to the characteristics of miniature units and new materials an automated assembling process becomes ever more difficult. With CRYO grip gripping tools were developed, which transport material units and carefully. (orig.) [German] Die steigenden Anforderungen an Leistungsfaehigkeit und Qualitaet fuehren zu Produkten hoeherer Integration und Funktionalitaet mit immer kleineren Komponenten. Ausserdem kommt es zur Anwendung neuer Werkstoffe mit verbesserten Eigenschaften wie z. B. Faserverbundkunststoffen. Aufgrund der Eigenschaften von Miniaturbauteilen und neuer Materialien wird ein automatisierter Montageprozess immer schwieriger. Mit CRYO-Greifern sind Greifwerkzeuge entwickelt worden, die materialschonend und sicher solche Bauteile transportieren. (orig.)
Grinsted, Aslak; Dahl-Jensen, Dorthe
The North Greenland Icecore Project (NorthGRIP) drill site was chosen in order to obtain a good Eemian record. At the present depth, 3001m, the Eemian interstadial has yet to be seen. Clearly the flow in this area is poorly understood and needs further investigation. After a review of specific...... no Eemian is observed is a high basal melt rate (2.7mm/a). The melting is a consequence of a higher geothermal heat flux than the expected 51mW/m^2 of the Precambrian shield. From our analyses it is concluded that the geothermal heat flux at NorthGRIP is 98mW/m^2.The high basalmelt rate also gives rise...
Mathiesen, J; Jensen, M H; Levinsen, M; Olesen, P; Dahl-Jensen, D; Svensson, A; Mathiesen, Joachim; Ferkinghoff-Borg, Jesper; Jensen, Mogens H.; Levinsen, Mogens; Olesen, Poul; Dahl-Jensen, Dorthe; Svensson, Anders
The North Greenland Ice Core Project (NorthGRIP) provides paleoclimatic information back to at least 115 kyr before present [Dahl-Jensen et al., 2002]. Each year, precipitation on the ice sheet covers it with a new layer of snow, which gradually transforms into ice crystals as the layer sinks into the ice sheet. The size distribution of ice crystals has been measured at selected depths in the upper 880 m of the NorthGRIP ice core [Svensson et al., 2003b], which cover a time span of 5300 years. The distributions change with time toward a universal curve, indicating a common underlying physical process in the formation of crystals. We identify this process as an interplay between fragmentation of the crystals and diffusion of their grain boundaries. The process is described by a two-parameter differential equation to which we obtain the exact solution. The solution is in excellent agreement with the experimentally observed distributions.
Jorgensen, L N; Sommer, T; Assaadzadeh, S;
between the groups in postoperative complications (33·7 versus 40·4 per cent; P = 0·215), rate of recurrent hernia within 1 year (1·2 per cent in both groups) or quality of life. CONCLUSION: The avoidance of suture fixation using a self-gripping mesh was not accompanied by a reduction in chronic symptoms......BACKGROUND: Many patients develop discomfort after open repair of a groin hernia. It was hypothesized that suture fixation of the mesh is a cause of these symptoms. METHODS: This patient- and assessor-blinded randomized multicentre clinical trial compared a self-gripping mesh (Parietene Progrip......(®) ) and sutured mesh for open primary repair of uncomplicated inguinal hernia by the Lichtenstein technique. Patients were assessed before surgery, on the day of operation, and at 1 and 12 months after surgery. The primary endpoint was moderate or severe symptoms after 12 months, including a combination...
The purpose of this study was to investigate the validity of the coefficient of variation as an identifier of feigned grip effort. Seventeen healthy female aged 20 to 25 yr participated in the study. Maximal and feigned efforts were measured isometrically and isokinetically (concentric and eccentric) using the Jamar and KinCom dynamometers, respectively. Findings indicated that, in all situations, the coefficient of variation derived from the maximal effort was significantly (P < 0.0001) lower than that derived from the feigned effort. However, the extent of overlapping between the two was sufficiently large to render the test sensitivities very low. Consequently, regardless of the measurement method, the coefficient of variation is not a valid tool for identifying feigned grip effort in healthy subjects.
... Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is a Hand Surgeon? What is ... nerves, skin and skin-related tissues, bones, and ... a systemic diseases. The hands may show changes noticed by the patient or ...
Salisbury, Curt Michael; Dullea, Kevin J.
Technologies pertaining to a robotic hand are described herein. The robotic hand includes one or more fingers releasably attached to a robotic hand frame. The fingers can abduct and adduct as well as flex and tense. The fingers are releasably attached to the frame by magnets that allow for the fingers to detach from the frame when excess force is applied to the fingers.
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Saint-Hilaire, Pascal; Shih, Albert Y.; Duncan, Nicole; Bain, Hazel; Maruca, Bennett A.; Kelley, Nicole; Godbole, Niharika; Kaufmann, Pierre; Caspi, Amir; Sample, John; Hoberman, Jane; Mochizuki, Brent; Olson, Jerry; Boggs, Steven E.; Zoglauer, Andreas; Hurford, Gordon J.; Smith, David M.; Tajima, Hiroyasu; Amman, Mark
The Gamma-Ray Imager/Polarimeter for Solar flares (GRIPS) high altitude balloon payload was successfully flown in January 2016 from Antarctica (Jan 19 to Jan 30).GRIPS provides a near-optimal combination of high-resolution imaging, spectroscopy, and polarimetry of solar-flare gamma ray/hard X-ray emissions from ~20 keV to >~10 MeV. GRIPS’s goal is to address questions raised by recent solar flare observations regarding particle acceleration and energy release, such as: What causes the spatial separation between energetic electrons producing hard X-rays and energetic ions producing gamma-ray lines? How anisotropic are the relativistic electrons, and why can they dominate in the corona? How do the compositions of accelerated and ambient material vary with space and time, and why? The spectrometer/polarimeter consists of six 3D position-sensitive germanium detectors (3D-GeDs), where each energy deposition is individually recorded with an energy resolution of a few keV FWHM and a spatial resolution gamma-ray energies (12.5 arcsec FWHM), sufficient to separate 2.2 MeV footpoint sources for almost all flares. Polarimetry is accomplished by analyzing the anisotropy of reconstructed Compton scattering in the 3D-GeDs, with an estimated minimum detectable polarization of a few percent at 150-650 keV in an X-class flare. GRIPS was also equipped with active BGO shields, and three piggy-back instruments: a solar terahertz radiometer (Solar-T), a hard X-ray spectrometer (SMASH), and a sonic anemometer (TILDAE).We will present an overview of GRIPS's first flight, the performance of its instruments and subsystems, including the solar pointing and aspect systems, and the current progress of our data analysis.
Full Text Available Aims: Inguinal hernia repair according to Lichtenstein technique has become the most common procedure performed by general surgeons. Heavy weight polypropylene meshes have been reported to stimulate inflammatory reaction responsible for mesh shrinkage when scar tissue evolved. Additionally, some concerns remain regarding the relationship between chronic pain and mesh fixation technique. In order to reduce those drawbacks, we have developed a new mesh for anterior tension free inguinal hernia repair which exhibits self-gripping absorbable properties. Materials and Methods: 52 patients (69 hernias were prospectivly operated with this mesh (SOFRADIM-France made of low-weight isoelastic large pores knitted fabric which incorporated resorbable micro hooks that provides self gripping properties to the mesh during the first months post-implantation. The fixation of the mesh onto the tissues is significantly facilitated. The mesh is secured around the cord with a self gripping flap. After complete tissular ingrowth and resorption of the PLA hooks, the low-weight (40 g/m2 polypropylene mesh insures the long term wall reinforcement. Results: Peroperativly, no complication was reported, the mesh was easy to handle and to fix. Discharge was obtained at Day 1. No perioperative complication occurred, return to daily activities was obtained at Day 5.5. At one month, no neurological pain or other complications were described. Conclusions: Based on the first results of this clinical study, this unique concept of low density self gripping mesh should allows an efficient treatment of inguinal hernia. It should reduce postoperative complications and the extent of required suture fixation, making the procedure more reproducible
Smidt, N.; Windt, A. van der; Assendelft, W.J.; Mourits, A.J.; Devillé, W.L.; Winter, F. de; Bouter, L.M.
Objective: To evaluate the interobserver reproducibility of the assessment of severity of complaints, grip strength, and pressure pain threshold in patients with lateral epicondylitis in primary care. Design: Two physiotherapists assessed independently, and in randomized order, the severity of
Smidt, N; van der Windt, DA; Assendelft, WJ; Mourits, AJ; Deville, WL; de Winter, AF; Bouter, LM
Objective: To evaluate the interobserver reproducibility of the assessment of severity of complaints, grip strength, and pressure pain threshold in patients with lateral epicondylitis in primary care. Design: Two physiotherapists assessed independently, and in randomized order, the severity of compl
Smidt, N.; Windt, A. van der; Assendelft, W.J.; Mourits, A.J.; Devillé, W.L.; Winter, F. de; Bouter, L.M.
Objective: To evaluate the interobserver reproducibility of the assessment of severity of complaints, grip strength, and pressure pain threshold in patients with lateral epicondylitis in primary care. Design: Two physiotherapists assessed independently, and in randomized order, the severity of compl
Iyengar, Veena; Santos, Marcio J; Aruin, Alexander S
We investigated whether slower velocity of arm movement affects grip-force generation in conditions with the finger touch provided to the wrist of the target arm. Nine subjects performed the task of lifting and transporting an object at slow, intermediate, and fast velocities with a light finger touch from the contralateral arm and without it. There was an effect of velocity of arm movement on grip-force generation in both conditions. However, when the no touch and touch trials performed with similar velocity were matched, the effect of touch on grip-force reduction was statistically significant (p touch conditions and underlines the importance of using a contralateral touch in the performance of activities of daily living. It also points to a possibility of the development of therapeutic advances for the enhancement of grip-force control in patients with neurological impairments.
Filteau, Suzanne; PrayGod, G; Woodd, Susannah L
involved HIV-infected Zambian and Tanzanian participants recruited to the NUSTART trial when malnourished (body mass index requiring ART. The relationship of grip strength to nutritional, infectious and demographic factors was assessed by multivariable linear regression at referral...
Mach, Douglas M.; Bateman, Monte G.; Blakeslee, Richard J.
We flew our Lightning Instrument Package (LIP) on the NASA Global Hawk as a part of the Genesis and Rapid Intensification Processes (GRIP) field program. The GRIP program was a NASA Earth science field experiment during the months of August and September, 2010. During the program, the LIP detected lighting from 48 of the 213 of the storms overflown by the Global Hawk. The time and location of tagged LIP flashes can be used as a "ground truth" dataset for checking the detection efficiency of the various long or extended range ground-based lightning detection systems available during the GRIP program. The systems analyzed included Vaisala Long Range (LR), Vaisala GLD360, the World Wide Lightning Location Network (WWLLN), and the Earth Networks Total Lightning Network (ENTLN). The long term goal of our research is to help understand the advantages and limitations of these systems so that we can utilize them for both proxy data applications and cross sensor validation of the GOES-R Geostationary Lightning Mapper (GLM) sensor when it is launched in the 2015 timeframe.
Nazir, Tatjana A; Hrycyk, Lianna; Moreau, Quentin; Frak, Victor; Cheylus, Anne; Ott, Laurent; Lindemann, Oliver; Fischer, Martin H; Paulignan, Yves; Delevoye-Turrell, Yvonne
Research in cognitive neuroscience has shown that brain structures serving perceptual, emotional, and motor processes are also recruited during the understanding of language when it refers to emotion, perception, and action. However, the exact linguistic and extralinguistic conditions under which such language-induced activity in modality-specific cortex is triggered are not yet well understood. The purpose of this study is to introduce a simple experimental technique that allows for the online measure of language-induced activity in motor structures of the brain. This technique consists in the use of a grip force sensor that captures subtle grip force variations while participants listen to words and sentences. Since grip force reflects activity in motor brain structures, the continuous monitoring of force fluctuations provides a fine-grained estimation of motor activity across time. In other terms, this method allows for both localization of the source of language-induced activity to motor brain structures and high temporal resolution of the recorded data. To facilitate comparison of the data to be collected with this tool, we present two experiments that describe in detail the technical setup, the nature of the recorded data, and the analyses (including justification about the data filtering and artifact rejection) that we applied. We also discuss how the tool could be used in other domains of behavioral research.
Ji, Aihong; Yuan, Shanshan; Hill, Iain; Wang, Huan; Barnes, W. Jon P.; Dai, Zhendong; Sitti, Metin
Most studies on the adhesive mechanisms of climbing animals have addressed attachment against flat surfaces, yet many animals can climb highly curved surfaces, like twigs and small branches. Here we investigated whether tree frogs use a clamping grip by recording the ground reaction forces on a cylindrical object with either a smooth or anti-adhesive, rough surface. Furthermore, we measured the contact area of fore and hindlimbs against differently sized transparent cylinders and the forces of individual pads and subarticular tubercles in restrained animals. Our study revealed that frogs use friction and normal forces of roughly a similar magnitude for holding on to cylindrical objects. When challenged with climbing a non-adhesive surface, the compressive forces between opposite legs nearly doubled, indicating a stronger clamping grip. In contrast to climbing flat surfaces, frogs increased the contact area on all limbs by engaging not just adhesive pads but also subarticular tubercles on curved surfaces. Our force measurements showed that tubercles can withstand larger shear stresses than pads. SEM images of tubercles revealed a similar structure to that of toe pads including the presence of nanopillars, though channels surrounding epithelial cells were less pronounced. The tubercles' smaller size, proximal location on the toes and shallow cells make them probably less prone to buckling and thus ideal for gripping curved surfaces. PMID:28228509
Full Text Available The investigation on the achieved data rate of the cellular system considering different grips of handsets at different frequencies using measurement results of the measurement campaign—which was carried out in the city of Aalborg—is presented in this paper. The achieved data rate of the multiple-input single-output (MISO interference channel is investigated. A typical propagation environment using two BSs and four handsets, like smart phones, held by four to eight different users was designed and multiple-input multiple-output (MIMO channels in different scenarios were measured. In this paper, two BSs and two handsets at each measurement time are considered. The impact of the different parameters like correlation, different grips of handsets, and different long term evolution (LTE frequency bands on the achieved data rate is investigated for different measurements. It could be concluded that the variations in the values of data rate are weakly associated with the different grips of handsets but more correlated with different frequencies.
Full Text Available Abstract Background Tight glucose control by intensive insulin therapy has become a key part of critical care and is an important field of study in acute coronary care. A balance has to be found between frequency of measurements and the risk of hypoglycemia. Current nurse-driven protocols are paper-based and, therefore, rely on simple rules. For safety and efficiency a computer decision support system that employs complex logic may be superior to paper protocols. Methods We designed and implemented GRIP, a stand-alone Java computer program. Our implementation of GRIP will be released as free software. Blood glucose values measured by a point-of-care analyzer were automatically retrieved from the central laboratory database. Additional clinical information was asked from the nurse and the program subsequently advised a new insulin pump rate and glucose sampling interval. Results Implementation of the computer program was uneventful and successful. GRIP treated 179 patients for a total of 957 patient-days. Severe hypoglycemia ( Conclusion A computer driven protocol is a safe and effective means of glucose control at a surgical ICU. Future improvements in the recommendation algorithm may further improve safety and efficiency.
Filteau, S; PrayGod, G; Woodd, S L; Friis, H; Heimburger, D C; Koethe, J R; Kelly, P; Kasonka, L; Rehman, A M
Low grip strength is a marker of frailty and a risk factor for mortality among HIV patients and other populations. We investigated factors associated with grip strength in malnourished HIV patients at referral to ART, and at 12 weeks and 2-3 years after starting ART. The study involved HIV-infected Zambian and Tanzanian participants recruited to the NUSTART trial when malnourished (body mass index <18.5 kg/m(2) ) and requiring ART. The relationship of grip strength to nutritional, infectious and demographic factors was assessed by multivariable linear regression at referral for ART (n = 1742) and after 12 weeks (n = 778) and 2-3 years of ART (n = 273). In analyses controlled only for sex, age and height, most nutrition and infection-related variables were associated with grip strength. However, in multivariable analyses, consistent associations were seen for fat-free mass index, mid-upper arm circumference, haemoglobin and systolic blood pressure, and a variable association with fat mass index in men. C-reactive protein and CD4 count had limited independent effects on grip strength, while receiving tuberculosis treatment was associated with weaker grip strength. In this population of originally malnourished HIV patients, poor grip strength was more strongly and independently associated with nutritional than with infection and inflammation variables. Programmes to improve health and survival of HIV patients should incorporate nutritional assessment and management and could use grip strength as a functional indicator of improving nutrition. © 2017 John Wiley & Sons Ltd.
Bayer, Thomas; Janka, Rolf [University of Erlangen-Nuremberg, Department of Radiology, Erlangen (Germany); Fries, Simon [Cantonal Hospital Lucerne, Orthopaedic Department, Wolhusen (Switzerland); Schweizer, Andreas [University of Zurich, Department of Orthopaedics, Balgrist, Zurich (Switzerland); Schoeffl, Isabelle [Klinikum Bamberg, Department of Pediatrics, Bamberg (Germany); Bongartz, Georg [University Basel, Department of Radiology, Basel (Switzerland)
The objectives of this study were the evaluation of flexor tendon pulley rupture of the fingers in the crimp grip position using magnetic resonance imaging (MRI) and the comparison of the results with MRI in the neutral position in a cadaver study. MRI in the crimp grip position and in the neutral position was performed in 21 cadaver fingers with artificially created flexor tendon pulley tears (combined pulley rupture, n = 14; single pulley rupture, n = 7). Measurement of the distance between the tendon and bone was performed. Images were evaluated by two readers, first independently and in cases of discrepancy in consensus. Sensitivity and specificity for detecting combined pulley ruptures were calculated. Tendon bone distances were significantly higher in the crimp grip position than in the neutral position. Sensitivity and specificity for detecting combined pulley rupture were 92.86 % and 100 % respectively in the crimp grip position and 78.57 % and 85.71 % respectively in the neutral position. Kappa values for interobserver reliability were 0.87 in the crimp grip position and 0.59 in the neutral position. MRI examination in the crimp grip position results in higher tendon bone distances by subjecting the pulleys to a higher strain, which facilitates image evaluation with higher interobserver reliability, higher sensitivity, and higher specificity for combined pulley rupture compared with examination in the neutral position. (orig.)
Full Text Available As a part of their professional responsibilities, police officers have authorization, in situation determined by law, to apply physical force or means of force. Due to given professional reasons, selection among the candidates as well as routine physical capability assessments, should have professional-methodological basis and scientific foundation. Muscle groups of particular reference in relationship to estimate general contraction characteristic in regard to force, and at the same time very easy to test are flexor muscles of fingers of the hand (test “hand squeeze”. The aim of this research is to define criterion characteristic for the population to function for selection and estimation of the hand squeeze force among policemen. This research had 723 participants, students of the Police Academy, as representatives of policemen between 19 and 24 years of age. In order to estimate force of hand grip (both right and left hand, we utilized tensiometric method, and standard procedure previously described (1. For the statistical analysis we used basic descriptive analysis, cluster analysis (defining 7 characteristic classes (clusters as a function of population tested –unacceptable, poor, below average, averaged, above average, excellent and superior, and factor analysis (definition of the selection test as a function of selection procedure (10. Our results indicate that averaged hand grip force among the tested population is 61.70±8.97 DaN (Min – Max=43.43-101.41 for left hand, and 65.11±9.34 DaN (Min – Max= 46.54-109.75 for right hand. The values for the force of defined cluster centers of left hand are: Cluster1-7=50.22, 55.76, 61.61, 67.84, 74.71, 84.02 and 97.15 DaN, and right hand are: Cluster1-7=53.40, 60.27, 66.10, 72.20, 79.70, 92.55 and 105.65 DaNFactor analysis results have shown that one factor has been isolated that accounted for 91.10 worthy variance. Regarding the individual variability, for the saturation of the isolated
Zhang, Xiaoying; Liu, Songhuai; Yang, Degang; Du, Liangjie; Wang, Ziyuan
[Purpose] The purpose of this study was to examine the immediate effects of therapeutic keyboard music playing on the finger function of subjects’ hands through measurements of the joint position error test, surface electromyography, probe reaction time, and writing time. [Subjects and Methods] Ten subjects were divided randomly into experimental and control groups. The experimental group used therapeutic keyboard music playing and the control group used grip training. All subjects were assessed and evaluated by the joint position error test, surface electromyography, probe reaction time, and writing time. [Results] After accomplishing therapeutic keyboard music playing and grip training, surface electromyography of the two groups showed no significant change, but joint position error test, probe reaction time, and writing time obviously improved. [Conclusion] These results suggest that therapeutic keyboard music playing is an effective and novel treatment for improving joint position error test scores, probe reaction time, and writing time, and it should be promoted widely in clinics. PMID:27630419
Zhang, Xiaoying; Liu, Songhuai; Yang, Degang; Du, Liangjie; Wang, Ziyuan
[Purpose] The purpose of this study was to examine the immediate effects of therapeutic keyboard music playing on the finger function of subjects' hands through measurements of the joint position error test, surface electromyography, probe reaction time, and writing time. [Subjects and Methods] Ten subjects were divided randomly into experimental and control groups. The experimental group used therapeutic keyboard music playing and the control group used grip training. All subjects were assessed and evaluated by the joint position error test, surface electromyography, probe reaction time, and writing time. [Results] After accomplishing therapeutic keyboard music playing and grip training, surface electromyography of the two groups showed no significant change, but joint position error test, probe reaction time, and writing time obviously improved. [Conclusion] These results suggest that therapeutic keyboard music playing is an effective and novel treatment for improving joint position error test scores, probe reaction time, and writing time, and it should be promoted widely in clinics.
Bongers, Raoul M.; Zaal, Frank T. J. M.; Jeannerod, Marc
Although variations in the standard prehensile pattern can be found in the literature, these alternative patterns have never been studied systematically. This was the goal of the current paper. Ten participants picked up objects with a pincer grip. Objects (3, 5, or 7 cm in diameter) were placed at
Diepgen, T L; Andersen, Klaus Ejner; Brandao, F M;
Summary Background Hand eczema is a long-lasting disease with a high prevalence in the background population. The disease has severe, negative effects on quality of life and sometimes on social status. Epidemiological studies have identified risk factors for onset and prognosis, but treatment...... of the disease is rarely evidence based, and a classification system for different subdiagnoses of hand eczema is not agreed upon. Randomized controlled trials investigating the treatment of hand eczema are called for. For this, as well as for clinical purposes, a generally accepted classification system...... for hand eczema is needed. Objectives The present study attempts to characterize subdiagnoses of hand eczema with respect to basic demographics, medical history and morphology. Methods Clinical data from 416 patients with hand eczema from 10 European patch test clinics were assessed. Results...
A kind of sensitive slippage sensor was developed by using piezoresistor, and a slippage observation system was constructed. The technique of STFT was applied to analyze the spectral information of slippage signal. Then slippage signal was distinguished with the signal resulted from different normal griping forces by using the result of DWT. The experimental results showed that the slippage signal was able to be effectively extracted regardless of different normal gripping force. At last, the experiment of gripping force adjustment was carried out by using two parallel fingers hand equipped with the designed slippage sensor. The experimental results of grasping actual fruits and vegetables demonstrated the promise of this slippage sensor in the agricultural picking robot.%利用压敏电阻作为敏感材料制作了一种灵敏的滑觉传感器,构建了滑觉信号观测系统.用短时傅里叶变换方法分析了滑觉信号的频谱特征,并运用离散小波变换结果来区分法向抓取力变化与实际发生的滑动信号,以使滑动信号检测结果不受法向抓取力变化的影响,试验结果表明滑觉检测的稳定性.运用二指平行手爪进行了实际的果蔬抓取试验,验证了基于滑觉检测的抓取力调节效果.
Appropriate hand deburring techniques have always been difficult to define because of the infinite variety of part shapes, sizes, materials, and burr conditions. This guide, however, has been prepared to assist those responsible for hand deburring. The purpose of the guide is to define Bendix Kansas City burr specifications and inspection practices; to define the results of practical tests on hand deburring; to define some typical in-house practices; and to define the in-house tools available for this work.
Panikkath, Deepa; Mojumder, Deb; Nugent, Kenneth
A 77-year-old woman presented with the complaint of observing her left hand moving without her knowledge while watching television. Her left hand stroked her face and hair as if somebody was controlling it. These movements lasted only half an hour but on recovery, she had left hemiparesis. Alien hand syndrome as the presentation of cardioembolic stroke is extremely rare but can be terrifying to patients. PMID:24982566
Bolon, Maureen K
The medical field has long recognized the importance of hand hygiene in preventing health care-associated infections, yet studies indicate that this important task is performed only 40% of the time. Health care workers cite several barriers to optimal performance of hand hygiene, but the time required to perform this task is foremost among them. Introduction of alcohol-based hand rubs, bundled interventions, and incorporation of technologies designed to monitor and promote hand hygiene all represent promising advances in this field. Copyright © 2016 Elsevier Inc. All rights reserved.
Kampf, G; Kramer, A; Rotter, M; Widmer, A
For more than 110 years hands of surgeons have been treated before a surgical procedure in order to reduce the bacterial density. The kind and duration of treatment, however, has changed significantly over time. Recent scientific evidence suggests a few changes with the aim to optimize both the efficacy and the dermal tolerance. Aim of this article is the presentation and discussion of new insights in surgical hand disinfection. A hand wash should be performed before the first disinfection of a day, ideally at least 10 min before the beginning of the disinfection as it has been shown that a 1 min hand wash significantly increases skin hydration for up to 10 min. The application time may be as short as 1.5 min depending on the type of hand rub. Hands and forearms should be kept wet with the hand rub for the recommended application time in any case. A specific rub-in procedure according to EN 12791 has been found to be suitable in order to avoid untreated skin areas. The alcohol-based hand rub should have a proven excellent dermal tolerance in order to ensure appropriate compliance. Considering these elements in clinical practice can have a significant impact to optimize the high quality of surgical hand disinfection for prevention of surgical site infections.
丁宇坤; 宇占军; 胡长春
主要介绍在大包线电气化改造工程中,地方电力资源不具备两路220 kV独立电源引入牵引变电所的情况下采用“手拉手”电源供电方式,对“手拉手”电源供电方式在经济性和可靠性两个方面的优越性进行论证,该种形式的电源供电方式具有结构简单、投资省、可靠性高等优点,是外部电源稀缺的情况下对牵引变电所实现两路电源供电的理想方法.%In the electrification renovation project of Datong-Baotou Railway, the "hand in hand" power supply mode was adopted because the local power sources didn't have two 220kV independent power supplies which should access to the traction substation. In this paper, the superiorities on the economic efficiency and reliability of "hand in hand" power supply mode are demonstrated. The paper thinks that; there are many advantages in this kind of power supply mode, such as simple structure, low investment and high reliability. So it is the ideal way to achieve two-way power supplies for the traction substation in the case of the scarcity of external power sources.
Moutet, F; Haloua, J P
Training of the hand surgeon HAND SURGEON A CONCEPT: The hand surgeon is supposed to be in charge of all the hand lesions regarding, skeleton, muscles, tendons, nerves and vessels. He has to be able to insure reparation and coverage of all of them. So he is involved in all the structures, which insure integrity and function of the hand. PURPOSE AND WAYS OF TRAINING: To obtain the asked ability, the hand surgeon training has to be global and sustained by two underlying surgical specialities: orthopedic surgery and plastic and reconstructive surgery. From 2000 after many years of dealings, a Right to the Title in Hand Surgery was born. This Right to the Title wants to be the formal recognition of the specific training of the hand surgeon. For the well-recognized ancient hand surgeons they need to be confirmed by one's peers. Now a day the hand surgeon has to satisfy to this specific training: Passed the complete training and exam of the Orthopedic or Plastic surgery board. Spent at least 6 months as resident in the other underlying specialty. Passed a microsurgery examination. Passed one of the four national Hand Surgery diplomas (DIU/Inter-Universitary Diploma). The examinations have been harmonized. A common formation is delivered regarding hand surgery, the way of examination is the same and the formation is 2 years long. The final exam is presented in front of board of examiners where a teacher of one of the other three national diplomas is present. Spent at least 2 years in a formative hand surgery unit, listed by the French College of Hand Surgeons, as senior surgeon. Those requirements are heavy to assume and need a heavy personal involvement. That seems to be necessary to have an ability level as high as possible. Emergency surgery practice is absolutely necessary in this training. All the 17 university formative hand surgery units listed by the French College of Hand Surgeons are members of the FESUM (European Federation of the Emergency Hand Units
... don't have soap and clean, running water? Washing hands with soap and water is the best way to get rid of germs in most situations. If soap and water are not available, use an alcohol-based hand sanitizer [423 KB] that contains at least 60% alcohol. ...
Cool, J.C.; Rijnsaardt, K.A.
Abstract of NL 9401195 (A) Pneumatically actuated hand tool for carrying out a mechanical operation, provided with an exchangeable gas cartridge in which the gas which is required for pneumatic actuation is stored. More particularly, the hand tool is provided with at least one pneumatic motor, at
BHAIRO, NH; NIJSTEN, MWN; VANDALEN, KC; TENDUIS, HJ
We studied the long-term sequelae of hand injuries as a result of playing volleyball. In a retrospective study, 226 patients with injuries of the hand who were seen over a 5-year period at our Trauma Department, were investigated. Females accounted for 66 % of all injuries. The mean age was 26
De Chiffre, Leonardo
This note is used in connection with a 3 x 2 hours laboratory exercise as a part of the course GEOMETRICAL METROLOGY AND MACHINE TESTING. The laboratory includes a demonstration of a series of hand measuring tools as well as a number of exercises, illustrating the use of hand measuring equipment...
BHAIRO, NH; NIJSTEN, MWN; VANDALEN, KC; TENDUIS, HJ
We studied the long-term sequelae of hand injuries as a result of playing volleyball. In a retrospective study, 226 patients with injuries of the hand who were seen over a 5-year period at our Trauma Department, were investigated. Females accounted for 66 % of all injuries. The mean age was 26 years
Simone, F.; Rizzello, G.; Seelecke, S.
Bio-inspired hand-like grippers actuated by Shape Memory Alloy (SMA) wires represent an emerging new technology with potential applications in many different fields, ranging from industrial assembly processes to biomedical systems. The inherently high energy density makes SMAs a natural choice for compact, lightweight, and silent actuator systems capable of producing a high amount of work, such as hand prostheses or robotic systems in industrial human/machine environments. In this work, a concept for a compact and versatile gripping system is developed, in which SMA wires are implemented as antagonistic muscles actuating an artificial hand with three fingers. In order to combine high gripping force with sufficient actuation speed, the muscle implementation pursues a multi-wire concept with several 0.1 mm diameter NiTi wires connected in parallel, in order to increase the surface-to-volume ratio for accelerated cooling. The paper starts with an illustration of the design concept of an individual 3-phalanx-finger, along with kinematic considerations for optimal placement of SMA wires. Three identical fingers are subsequently fabricated via 3D printing and assembled into a hand-like gripper. The maximum displacement of each finger phalanx is measured, and an average phalanxes dynamic responsiveness is evaluated. SMA self-sensing is documented by experiments relating the wires change in resistance to the finger motion. Several finger force measurements are also performed. The versatility of the gripper is finally documented by displaying a variety of achievable grasping configurations.
Xue Yuan; Yongduan Song; Xueye Wei
@@ A hand vein authentication system in which the identity of an individual can be readily confirmed upon gripping a handle is proposed.This recognition method incorporates infrared light-emitting diode (LED) onto a door handle and sets a charge-coupled device (CCD) camera on the other side of the hand.It builds on fuzzy c-means clustering and parallel neural networks (NNs); moreover, it is expected to solve the pattern recognition problem in large-scale databases using NNs due to its self-learning and parallel processing capabilities and by effectively incorporating training patterns.The experimental results validate the efficiency of the proposed algorithm.%A hand vein authentication system in which the identity of an individual can be readily confirmed upon gripping a handle is proposed. This recognition method incorporates infrared light-emitting diode (LED)onto a door handle and sets a charge-coupled device (CCD) camera on the other side of the hand. It builds on fuzzy c-means clustering and parallel neural networks (NNs); moreover, it is expected to solve the pattern recognition problem in large-scale databases using NNs due to its self-learning and parallel processing capabilities and by effectively incorporating training patterns. The experimental results validatethe efficiency of the proposed algorithm.
Williamson, J. Scott; Manktelow, Ralph T.; Kelly, Louise; Marcuzzi, A.; Mahabir, Raman C.
Objective To assess the utility of toe-to-finger transfers (TFTs) for post-traumatic reconstruction of the fingerless hand. Design A case series. Setting A regional trauma centre. Patients Eight men, mean age was 36 years (range from 25–59 yr), who had lost all the fingers from a hand due to a crush–degloving injury (6 patients), frostbite (1 patient) or a burn injury (1 patient). Intervention TFT. Twelve TFTs were cone and the mean time from injury to reconstruction was 17.2 months. Main outcome measures Objective (range of motion, moving 2-point discrimination, grip strength, key pinch, Jebsen–Taylor hand assessment, return to work) and subjective (activities of daily living and a questionnaire) measures. Results Eleven of the 12 transfers survived. Six of the 7 in whom the transfer was successful were available for follow-up (mean 45 mo). Range of motion was 10° at the distal interphalangeal joint, 18° at the proximal interphalangeal joint and 59° at the metacarpophalangeal joint. Sensation was protective in all. Grip strength and key pinch were 26.1% and 70.2% of the contralateral hand respectively. Jebsen–Taylor assessment indicated that basic activities were possible but slowed. All 6 patients returned to work and could perform 92.6% of the activities of daily living unassisted. Hand and foot symptoms were mild. Two-thirds were appearance conscious, 5 of the 6 went on to altered vocations and all reported overall satisfaction as high. Conclusion This study supports TFT for reconstruction of the fingerless hand in that, although transferred toe function may be poorer than a normal finger, the hand is restored to a useful, sensate and versatile functional unit, such that global hand and patient function, as well as patient satisfaction, are very good. PMID:11504261
Le, Ada; Niemeier, Matthias
When we grasp an object using one hand, the opposite hemisphere predominantly guides the motor control of grasp movements (Davare et al., 2007; Rice et al., 2007). However, it is unclear whether visual object analysis for grasp control relies more on inputs (a) from the contralateral than the ipsilateral visual field, (b) from one dominant visual field regardless of the grasping hand, or (c) from both visual fields equally. For bimanual grasping of a single object we have recently demonstrated a visual field preference for the left visual field (Le and Niemeier, 2013a,b), consistent with a general right-hemisphere dominance for sensorimotor control of bimanual grasps (Le et al., 2014). But visual field differences have never been tested for unimanual grasping. Therefore, here we asked right-handed participants to fixate to the left or right of an object and then grasp the object either with their right or left hand using a precision grip. We found that participants grasping with their right hand performed better with objects in the right visual field: maximum grip apertures (MGAs) were more closely matched to the object width and were smaller than for objects in the left visual field. In contrast, when people grasped with their left hand, preferences switched to the left visual field. What is more, MGA scaling with the left hand showed greater visual field differences compared to right-hand grasping. Our data suggest that, visual object analysis for unimanual grasping shows a preference for visual information from the ipsilateral visual field, and that the left hemisphere is better equipped to control grasps in both visual fields.
Salehi, Seyed Hamid; Fatemi, Mohammad Javad; Sedghi, Maryam; Niazi, Mitra
Despite a general consensus regarding the impacts of early excision and grafting (EE and G) of burned hand on the reducing of treatment cost and hospital stay, there are some controversial issues about its effect on the outcome of hand function. This study conducted to compare the results of the EE and G and delayed skin grafting in deep hand burns regarding the hand functional outcome. This study was conducted from April 2012 to November 2013 in sixty patients with deep thermal burns of the dorsal hand with total body surface area (TBSA) <20% who were admitted to special burn hospital. After standard primary burn care and resuscitation, necessary procedures (EE and G or more conservative treatment) were performed based on the patients' conditions. The patients were placed into early excision (No. =30) and delayed excision group (No. =30). Total active motion (TAM) of fingers, grip strength of the hand and the assessment of disabilities of the arm, shoulder and hand questionnaire, were measured in all patients 6 months after grafting. The average percentage of TBSA in the EE and G group was more than the delayed excision group (17.34% ±5.12% vs. 15.64% ±5.83%), this difference was not significant (P = 0.23). After 6 months, the average of the TAM and grip strength in the EE and G group was significantly more than that of the delayed group (P < 0.0001 and P = 0.019). The present study showed that EE and G with proper physical therapy and rehabilitation management provides a higher functional outcome in dorsal deep burned hand.
Seyed Hamid Salehi
Full Text Available Background: Despite a general consensus regarding the impacts of early excision and grafting (EE and G of burned hand on the reducing of treatment cost and hospital stay, there are some controversial issues about its effect on the outcome of hand function. This study conducted to compare the results of the EE and G and delayed skin grafting in deep hand burns regarding the hand functional outcome. Materials and Methods: This study was conducted from April 2012 to November 2013 in sixty patients with deep thermal burns of the dorsal hand with total body surface area (TBSA <20% who were admitted to special burn hospital. After standard primary burn care and resuscitation, necessary procedures (EE and G or more conservative treatment were performed based on the patients' conditions. The patients were placed into early excision (No. =30 and delayed excision group (No. =30. Total active motion (TAM of fingers, grip strength of the hand and the assessment of disabilities of the arm, shoulder and hand questionnaire, were measured in all patients 6 months after grafting. Results: The average percentage of TBSA in the EE and G group was more than the delayed excision group (17.34% ±5.12% vs. 15.64% ±5.83%, this difference was not significant (P = 0.23. After 6 months, the average of the TAM and grip strength in the EE and G group was significantly more than that of the delayed group (P < 0.0001 and P = 0.019. Conclusion: The present study showed that EE and G with proper physical therapy and rehabilitation management provides a higher functional outcome in dorsal deep burned hand.
... handrub? How to handwash? RUB HANDS FOR HAND HYGIENE! WASH HANDS WHEN VISIBLY SOILED Duration of the entire procedure: ... from its use. When? YOUR 5 MOMENTS FOR HAND HYGIENE 1 BEFORETOUCHINGA PATIENT 2 B P ECFLOER R ...
Full Text Available Background: Proximal phalangeal fractures are commonly encountered fractures in the hand. Majority of them are stable and can be treated by non-operative means. However, unstable fractures i.e. those with shortening, displacement, angulation, rotational deformity or segmental fractures need surgical intervention. This prospective study was undertaken to evaluate the functional outcome after surgical stabilization of these fractures with joint-sparing multiple intramedullary nailing technique. Materials and Methods: Thirty-five patients with 35 isolated unstable proximal phalangeal shaft fractures of hand were managed by surgical stabilization with multiple intramedullary nailing technique. Fractures of the thumb were excluded. All the patients were followed up for a minimum of six months. They were assessed radiologically and clinically. The clinical evaluation was based on two criteria. 1. total active range of motion for digital functional assessment as suggested by the American Society for Surgery of Hand and 2. grip strength. Results: All the patients showed radiological union at six weeks. The overall results were excellent in all the patients. Adventitious bursitis was observed at the point of insertion of nails in one patient. Conclusion: Joint-sparing multiple intramedullary nailing of unstable proximal phalangeal fractures of hand provides satisfactory results with good functional outcome and fewer complications.
Full Text Available This paper was conceived to present the ideology of utilizing advanced actuators to design and develop innovative, lightweight, powerful, compact, and as much as possible dexterous robotic hands. The key to satisfying these objectives is the use of Shape Memory Alloys (SMAs to power the joints of the robotic hand. The mechanical design of a dexterous robotic hand, which utilizes non-classical types of actuation and information obtained from the study of biological systems, is presented in this paper. The type of robotic hand described in this paper will be utilized for applications requiring low weight, power, compactness, and dexterity.
Full Text Available Introduction: Handcycling is a relatively new wheelchair sport that has gained increased popularity for people with lower limb disabilities. The aim of this study was to examine the effect of three different grip positions on physical parameters during handcycling in a laboratory setting.Methods: Twenty one able-bodied participants performed three maximum incremental handcycling tests until exhaustion, each with a different grip angle. The angle between the grip and the crank was randomly set at 90° (horizontal, 0° (vertical or 10° (diagonal. The initial load was 20 W and increased by 20 W each five minutes. In addition, participants performed a 20 s maximum effort.Results: The relative peak functional performance (W/kg, peak heart rate (bpm, associated lactate concentrations (mmol/l and peak oxygen uptake per kilogram body weight (ml.min-1.kg-1 for the different grip positions during the stage test were: (a Horizontal: 1.43 ± 0.21 W/kg, 170.14 ± 12.81 bpm, 9.54 ± 1.93 mmol/l, 30.86 ± 4.57 ml/kg; (b Vertical: 1.38 ± 0.20 W/kg, 171.81 ± 13.87 bpm, 9.91 ± 2.29 mmol/l, 29.75 ± 5.13 ml/kg; (c Diagonal: 1.40 ± 0.22 W/kg, 169.19 ± 13.31 bpm, 9.34 ± 2.36 mmol/l, 29.39 ± 4.70 ml/kg. Statistically significant (p <0.05 differences could only be found for lactate concentration between the vertical grip position and the other grips during submaximal handcycling. Conclusion: The orientation of three different grip angles made no difference to the peak load achieved during an incremental handcycling test and a 20 second maximum effort. At submaximal load, higher lactate concentrations were found when the vertical grip position was used, suggesting that this position may be less efficient than the alternative diagonal or horizontal grip positions.
Dickinson Bryony A
Full Text Available Abstract Background Long-term depression (LTD in the hippocampus can be induced by activation of different types of G-protein coupled receptors, in particular metabotropic glutamate receptors (mGluRs and muscarinic acethycholine receptors (mAChRs. Since mGluRs and mAChRs activate the same G-proteins and isoforms of phospholipase C (PLC, it would be expected that these two forms of LTD utilise the same molecular mechanisms. However, we find a distinct mechanism of LTD involving GRIP and liprin-α. Results Whilst both forms of LTD require activation of tyrosine phosphatases and involve internalisation of AMPARs, they use different molecular interactions. Specifically, mAChR-LTD, but not mGluR-LTD, is blocked by peptides that inhibit the binding of GRIP to the AMPA receptor subunit GluA2 and the binding of GRIP to liprin-α. Thus, different receptors that utilise the same G-proteins can regulate AMPAR trafficking and synaptic efficacy via distinct molecular mechanisms. Conclusion Our results suggest that mAChR-LTD selectively involves interactions between GRIP and liprin-α. These data indicate a novel mechanism of synaptic plasticity in which activation of M1 receptors results in AMPAR endocytosis, via a mechanism involving interactions between GluA2, GRIP and liprin-α.
This paper was conceived to present the ideology of utilizing advanced actuators to design and develop innovative, lightweight, powerful, compact, and as much as possible dexterous robotic hands. The key to satisfying these objectives is the use of Shape Memory Alloys (SMAs) to power the joints of the robotic hand. The mechanical design of a dexterous robotic hand, which utilizes non-classical types of actuation and information obtained from the study of biological systems, is presented in th...
Ryu, Jeseong; Son, Jongsang; Ahn, Soonjae; Shin, Isu; Kim, Youngho
A massage can be beneficial to relieve muscle tension on the neck and shoulder area. Various massage systems have been developed, but their motions are not uniform throughout different body parts nor specifically targeted to the neck and shoulder areas. Pressure pattern and finger movement trajectories of the circular friction hand massage on trapezius, levator scapulae, and deltoid muscles were determined to develop a massage system that can mimic the motion and the pressure of the circular friction massage. During the massage, finger movement trajectories were measured using a 3D motion capture system, and finger pressures were simultaneously obtained using a grip pressure sensor. Results showed that each muscle had different finger movement trajectory and pressure pattern. The trapezius muscle experienced a higher pressure, longer massage time (duration of pressurization), and larger pressure-time integral than the other muscles. These results could be useful to design a better massage system simulating human finger movements.
Full Text Available Pathological conditions of the hand consequent to injuries, paralysis, disease, arthritis and congenital difference results in loss or limitation of function, deformities, stiffness, inadequate power and poor position for pinch. The pathogenesis of deformities is influenced by bio-mechanical principles of joints and muscle function. The crippling impact of secondary changes due to edema, soft tissue contractures, muscle shortening and functional adaptations also have a mechanical basis. For clinicians and hand therapists, it is necessary to understand these fundamental principles of biomechanics to plan treatment modalities. Interpretation of mechanics of hand deformities in rheumatoid arthritis and paralysis will enable the treating team to identify the appropriate interventions of splinting, therapy and surgical procedures. Basic knowledge of the principles of hand clinical bio-mechanics will help the beginner to sail through the multitude of tendon transfers described in the text books of hand surgery and find the best solution for a particular clinical presentation. Similarly, knowledge of bio-mechanics will provide solutions to an experienced surgeon to plan treatment protocols for complex situations. The article presents a concise summary of the basic principles of hand bio-mechanics for common hand conditions seen in clinical practice. Understanding and applying these principles will help clinicians in planning and devising treatment options for common and complex hand conditions.
Zabet, Nicolae Radu; Adryan, Boris
Transcription factors (TFs) are proteins that regulate gene activity by binding to specific sites on the DNA. Understanding the way these molecules locate their target site is of great importance in understanding gene regulation. We developed a comprehensive computational model of this process and estimated the model parameters in (N.R.Zabet and B.Adryan, submitted for publication). GRiP (gene regulation in prokaryotes) is a highly versatile implementation of this model and simulates the search process in a computationally efficient way. This program aims to provide researchers in the field with a flexible and highly customizable simulation framework. Its features include representation of DNA sequence, TFs and the interaction between TFs and the DNA (facilitated diffusion mechanism), or between various TFs (cooperative behaviour). The software will record both information on the dynamics associated with the search process (locations of molecules) and also steady-state results (affinity landscape, occupancy-bias and collision hotspots). http://logic.sysbiol.cam.ac.uk/grip, program and source code
Bateman, Monte G.; Blakeslee, Richard J.; Mach, Douglas M.
During the Genesis and Rapid Intensification Processes (GRIP) field program, a system of 6 electric field mills was flown on one of NASA's Global Hawk aircraft. We placed several mills on the aircraft to enable us to measure the vector electric field. We created a distributed, ethernet-connected system so that each sensor has its own embedded Linux system, complete with web server. This makes our current generation system fully "sensor web enabled." The Global Hawk has several unique qualities, but relevant to quality storm electric field measurements are high altitude (20 km) and long duration (20-30 hours) flights. There are several aircraft participating in the GRIP program, and coordinated measurements are happening. Lightning and electric field measurements will be used to study the relationships between lightning and other storm characteristics. It has been long understood that lightning can be used as a marker for strong convective activity. Past research and field programs suggest that lightning flash rate may serve as an indicator and precursor for rapid intensification change in tropical cyclones and hurricanes. We have the opportunity to sample hurricanes for many hours at a time and observe intensification (or de-intensification) periods. The electrical properties of hurricanes during such periods are not well known. American
André, T.; Lévesque, V.; Hayward, V.; Lefèvre, P.; Thonnard, J.-L.
The dynamics of fingertip contact manifest themselves in the complex skin movements observed during the transition from a stuck state to a fully developed slip. While investigating this transition, we found that it depended on skin hydration. To quantify this dependency, we asked subjects to slide their index fingertip on a glass surface while keeping the normal component of the interaction force constant with the help of visual feedback. Skin deformation inside the contact region was imaged with an optical apparatus that allowed us to quantify the relative sizes of the slipping and sticking regions. The ratio of the stuck skin area to the total contact area decreased linearly from 1 to 0 when the tangential force component increased from 0 to a maximum. The slope of this relationship was inversely correlated to the normal force component. The skin hydration level dramatically affected the dynamics of the contact encapsulated in the course of evolution from sticking to slipping. The specific effect was to reduce the tendency of a contact to slip, regardless of the variations of the coefficient of friction. Since grips were more unstable under dry skin conditions, our results suggest that the nervous system responds to dry skin by exaggerated grip forces that cannot be simply explained by a change in the coefficient of friction. PMID:21490002
In everyday life, one of the most frequent activities involves accelerating and decelerating an object held in precision grip. In many contexts, humans scale and synchronize their grip force (GF), normal to the finger/object contact, in anticipation of the expected tangential load force (LF), resulting from the combination of the gravitational and the inertial forces. In many contexts, GF and LF are linearly coupled. A few studies have examined how we adjust the parameters-gain and offset-of this linear relationship. However, the question remains open as to how the brain adjusts GF regardless of whether LF is generated by different combinations of weight and inertia. Here, we designed conditions to generate equivalent magnitudes of LF by independently varying mass and movement frequency. In a control experiment, we directly manipulated gravity in parabolic flights, while other factors remained constant. We show with a simple computational approach that, to adjust GF, the brain is sensitive to how LFs are produced at the fingertips. This provides clear evidence that the analysis of the origin of LF is performed centrally, and not only at the periphery.
Sahawneh, Saleem; Farrar, Spencer; Johnson, James; Jones, W. Linwood; Roberts, Jason; Biswas, Sayak; Cecil, Daniel
Microwave remote sensing observations of hurricanes, from NOAA and USAF hurricane surveillance aircraft, provide vital data for hurricane research and operations, for forecasting the intensity and track of tropical storms. The current operational standard for hurricane wind speed and rain rate measurements is the Stepped Frequency Microwave Radiometer (SFMR), which is a nadir viewing passive microwave airborne remote sensor. The Hurricane Imaging Radiometer, HIRAD, will extend the nadir viewing SFMR capability to provide wide swath images of wind speed and rain rate, while flying on a high altitude aircraft. HIRAD was first flown in the Genesis and Rapid Intensification Processes, GRIP, NASA hurricane field experiment in 2010. This paper reports on geophysical retrieval results and provides hurricane images from GRIP flights. An overview of the HIRAD instrument and the radiative transfer theory based, wind speed/rain rate retrieval algorithm is included. Results are presented for hurricane wind speed and rain rate for Earl and Karl, with comparison to collocated SFMR retrievals and WP3D Fuselage Radar images for validation purposes.
Zill, Sasha N; Chaudhry, Sumaiya; Exter, Annelie; Büschges, Ansgar; Schmitz, Josef
The mechanics of substrate adhesion has recently been intensively studied in insects but less is known about the sensorimotor control of substrate engagement. We characterized the responses and motor effects of tarsal campaniform sensilla in stick insects to understand how sensory signals of force could contribute to substrate grip. The tarsi consist of a chain of segments linked by highly flexible articulations. Morphological studies showed that one to four campaniform sensilla are located on the distal end of each segment. Activities of the receptors were recorded neurographically and sensilla were identified by stimulation and ablation of their cuticular caps. Responses were characterized to bending forces and axial loads, muscle contractions and to forces applied to the retractor apodeme (tendon). The tarsal sensilla effectively encoded both the rate and amplitude of loads and muscle forces, but only when movement was resisted. Mechanical stimulation of the receptors produced activation of motor neurons in the retractor unguis and tibial flexor muscles. These findings indicate that campaniform sensilla can provide information about the effectiveness of the leg muscles in generating substrate adherence. They can also produce positive force feedback that could contribute to the development of substrate grip and stabilization of the tarsal chain.
The coefficient of variation (CV) is a widely used measure of sincerity of effort of grip strength despite contradictory research findings and lack of empirical support in the literature. The purpose of this study was to investigate whether the CV is an appropriate measure of sincerity of effort. One hundred forty-six uninjured volunteers underwent a series of grip strength tests. The mean, standard deviation (SD), and CV of repeated strength trials were calculated, and paired comparisons were conducted between maximal and submaximal efforts. While the mean of maximal trials was significantly greater, there were no differences in SD between maximal and submaximal trials. Therefore, the increased CV associated with submaximal effort was an artifact of reduced torque rather than an indicator of a true increase in variability. Consequently, the CV is not an appropriate measure of sincerity of effort of grip strength.
... us eat, dress, write, earn a living, create art and do many other activities. To accomplish these ... 2009 American Society for Surgery of the Hand. Definition developed by ASSH Council. Other Links CME Mission ...
... Therapist? Media Find a Hand Surgeon Home Anatomy Osteoarthritis Email to a friend * required fields From * To * ... for those with osteoarthritis. TREATMENT The Diagnosis of Osteoarthritis When diagnosing osteoarthritis, your doctor will ask you ...
... include: Arthritis Fractures Dislocations Bad sprains Tendon and muscle injuries Evaluating Hand Stiffness Your doctor will ask when the stiffness ... scan. CAUSES SIGNS AND ... stretching exercises for the joints and muscles to help loosen them. Different types of splints ...
Full Text Available ... captioning. Videos are prepared for different audiences including, children, parents, and public health professionals. More > Hand Hygiene ... captioning. Videos are prepared for different audiences including, children, parents, and public health professionals. More > File Formats ...
Full Text Available ... get more than a million infections in the hospital while being treated for something else. The best ... reminding healthcare providers to practice hand hygiene in hospitals and other healthcare facilities. Release Date: 8/4/ ...
Full Text Available ... To Health (4:17) Vital Signs High Blood Pressure Spanish Diseases & Conditions Hablemos de la Influenza Influenza ... Videos are prepared for different audiences including, children, parents, and public health professionals. More > Hand Hygiene Saves ...
Full Text Available ... Lives shows how patients can play an active role in reminding healthcare providers to practice hand hygiene ... Director for Communication, Division of News and Electronic Media Email Recommend Tweet YouTube Instagram Listen Watch RSS ...
Full Text Available ... Please Parents Want To Do What′s Best The Obesity Epidemic Outbreaks CDC: Protecting Americans through Global Health ... captioning. Videos are prepared for different audiences including, children, parents, and public health professionals. More > Hand Hygiene ...
... lotion or cream can be harmful if swallowed: Dimethicone Mineral oil Paraffins (waxes) Petrolatum Various alcohols Where ... Hand cream poisoning References Caraccio TR, McFee RB. Cosmetics and toilet articles. In: Shannon MW, Borron SW, ...
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Davidsen, Jacob; Christiansen, Ellen Tove
, to construct and problem solve, and to show and imitate. The analyses show how a space emerges from the interaction between the children and the touchscreen, and how their hand movements reveal intelligence-as-action. Three situations with three different pairs were analysed to explore how children use......Apart from touching the screen, what is the role of the hands for children collaborating around touchscreens? Based on embodied and multimodal interaction analysis of 8- and 9-year old pairs collaborating around touchscreens, we conclude that children use their hands to constrain and control access...... their hands in activities around touchscreens, focusing in particular on how they collaborate. The analysis presented here is part of a research study on the use of touchscreens in children’s embodied and multimodal collaborative learning activities in their everyday classrooms. The general aim of the study...
Full Text Available ... Thinking The Value of Systems Thinking (10:09) Systems Mapping: The Basics ... how patients can play an active role in reminding healthcare providers to practice hand hygiene in hospitals and ...
Full Text Available When we grasp an object using one hand, the opposite hemisphere predominantly guides the motor control of grasp movements (Davare et al. 2007; Rice et al. 2007. However, it is unclear whether visual object analysis for grasp control relies more on inputs (a from the contralateral than the ipsilateral visual field, (b from one dominant visual field regardless of the grasping hand, or (c from both visual fields equally. For bimanual grasping of a single object we have recently demonstrated a visual field preference for the left visual field (Le and Niemeier 2013a, 2013b, consistent with a general right-hemisphere dominance for sensorimotor control of bimanual grasps (Le et al., 2013. But visual field differences have never been tested for unimanual grasping. Therefore, here we asked right-handed participants to fixate to the left or right of an object and then grasp the object either with their right or left hand using a precision grip. We found that participants grasping with their right hand performed better with objects in the right visual field: maximum grip apertures (MGAs were more closely matched to the object width and were smaller than for objects in the left visual field. In contrast, when people grasped with their left hand, preferences switched to the left visual field. What is more, MGA scaling showed greater visual field differences compared to right-hand grasping. Our data suggest that, visual object analysis for unimanual grasping shows a preference for visual information from the ipsilateral visual field, and that the left hemisphere is better equipped to control grasps in both visual fields.
Browne, Fiona; Wang, Haiying; Zheng, Huiru; Azuaje, Francisco
Information about protein interaction networks is fundamental to understanding protein function and cellular processes. Interaction patterns among proteins can suggest new drug targets and aid in the design of new therapeutic interventions. Efforts have been made to map interactions on a proteomic-wide scale using both experimental and computational techniques. Reference datasets that contain known interacting proteins (positive cases) and non-interacting proteins (negative cases) are essential to support computational prediction and validation of protein-protein interactions. Information on known interacting and non interacting proteins are usually stored within databases. Extraction of these data can be both complex and time consuming. Although, the automatic construction of reference datasets for classification is a useful resource for researchers no public resource currently exists to perform this task. GRIP (Gold Reference dataset constructor from Information on Protein complexes) is a web-based system that provides researchers with the functionality to create reference datasets for protein-protein interaction prediction in Saccharomyces cerevisiae. Both positive and negative cases for a reference dataset can be extracted, organised and downloaded by the user. GRIP also provides an upload facility whereby users can submit proteins to determine protein complex membership. A search facility is provided where a user can search for protein complex information in Saccharomyces cerevisiae. GRIP is developed to retrieve information on protein complex, cellular localisation, and physical and genetic interactions in Saccharomyces cerevisiae. Manual construction of reference datasets can be a time consuming process requiring programming knowledge. GRIP simplifies and speeds up this process by allowing users to automatically construct reference datasets. GRIP is free to access at http://rosalind.infj.ulst.ac.uk/GRIP/.
Full Text Available Abstract Background Information about protein interaction networks is fundamental to understanding protein function and cellular processes. Interaction patterns among proteins can suggest new drug targets and aid in the design of new therapeutic interventions. Efforts have been made to map interactions on a proteomic-wide scale using both experimental and computational techniques. Reference datasets that contain known interacting proteins (positive cases and non-interacting proteins (negative cases are essential to support computational prediction and validation of protein-protein interactions. Information on known interacting and non interacting proteins are usually stored within databases. Extraction of these data can be both complex and time consuming. Although, the automatic construction of reference datasets for classification is a useful resource for researchers no public resource currently exists to perform this task. Results GRIP (Gold Reference dataset constructor from Information on Protein complexes is a web-based system that provides researchers with the functionality to create reference datasets for protein-protein interaction prediction in Saccharomyces cerevisiae. Both positive and negative cases for a reference dataset can be extracted, organised and downloaded by the user. GRIP also provides an upload facility whereby users can submit proteins to determine protein complex membership. A search facility is provided where a user can search for protein complex information in Saccharomyces cerevisiae. Conclusion GRIP is developed to retrieve information on protein complex, cellular localisation, and physical and genetic interactions in Saccharomyces cerevisiae. Manual construction of reference datasets can be a time consuming process requiring programming knowledge. GRIP simplifies and speeds up this process by allowing users to automatically construct reference datasets. GRIP is free to access at http://rosalind.infj.ulst.ac.uk/GRIP/.
Coradinia, Josinéia Gresele; Kakihata, Camila Mayumi Martin; Kunz, Regina Inês; Errero, Tatiane Kamada; Bonfleur, Maria Lúcia; Bertolini, Gladson Ricardo Flor
To verify the functionality through muscle grip strength in animals with obesity induced by monosodium glutamate (MSG) and in control animals, which suffered compression of the right median nerve, and treated with swimming with overload. During the first five days of life, neonatal Wistar rats received subcutaneous injections of MSG. The control group received a hypertonic saline solution. Forty-eight rats were divided into six groups: G1 (control); G2 (control + injury); G3 (control + injury + swimming); G4 (obese); G5 (obese + injury); G6 (obese + injury + swimming). The animals in groups G2, G3, G5 and G6 were submitted to compression of the median nerve and G3 and G6 groups were treated, after injury, with swimming exercise with load for three weeks. The swimming exercise had a progressive duration, according to the week, of 20, 30 and 40minutes. Muscle strength was assessed using a grip strength meter preoperatively and on the 3rd, 7th, 14th and 21st days after surgery. The results were expressed and analyzed using descriptive and inferential statistics. When the grip strength was compared among assessments regardless of group, in the second assessment the animals exhibited lower grip strength. G1 and G4 groups had greater grip strength, compared to G2, G3, G4 and G6. The swimming exercise with overload has not been effective in promoting improvement in muscle grip strength after compression injury of the right median nerve in control and in obese-MSG rats. Copyright © 2013 Elsevier Editora Ltda. All rights reserved.
Boyer, Doug M; Yapuncich, Gabriel S; Chester, Stephen G B; Bloch, Jonathan I; Godinot, Marc
Questions surrounding the origin and early evolution of primates continue to be the subject of debate. Though anatomy of the skull and inferred dietary shifts are often the focus, detailed studies of postcrania and inferred locomotor capabilities can also provide crucial data that advance understanding of transitions in early primate evolution. In particular, the hand skeleton includes characteristics thought to reflect foraging, locomotion, and posture. Here we review what is known about the early evolution of primate hands from a comparative perspective that incorporates data from the fossil record. Additionally, we provide new comparative data and documentation of skeletal morphology for Paleogene plesiadapiforms, notharctines, cercamoniines, adapines, and omomyiforms. Finally, we discuss implications of these data for understanding locomotor transitions during the origin and early evolutionary history of primates. Known plesiadapiform species cannot be differentiated from extant primates based on either intrinsic hand proportions or hand-to-body size proportions. Nonetheless, the presence of claws and a different metacarpophalangeal [corrected] joint form in plesiadapiforms indicate different grasping mechanics. Notharctines and cercamoniines have intrinsic hand proportions with extremely elongated proximal phalanges and digit rays relative to metacarpals, resembling tarsiers and galagos. But their hand-to-body size proportions are typical of many extant primates (unlike those of tarsiers, and possibly Teilhardina, which have extremely large hands). Non-adapine adapiforms and omomyids exhibit additional carpal features suggesting more limited dorsiflexion, greater ulnar deviation, and a more habitually divergent pollex than observed plesiadapiforms. Together, features differentiating adapiforms and omomyiforms from plesiadapiforms indicate increased reliance on vertical prehensile-clinging and grasp-leaping, possibly in combination with predatory behaviors in
VAN ZWIETEN K. J.; K. Schmidt; Helder, P.; Lippens, P.; Zoubova, I.; Zinkovsky, A.
With a conventional mouse a combination of thumb, ring- and little finger is required to realize optimal control in the horizontal (X-Y) plane. By providing a supporting contour for hand palm and fingers, it was noted that gripping and pinching of thumb and fingers (m. extensor carpi radialis longus and brevis) to control the mouse in the X-Y plane was no longer necessary. The supporting contour enables a near to fully relaxed flexor and extensor muscle position which is reflected by a signif...
Silva, Danilo C; Medola, Fausto O; Bonfim, Gabriel H C; Paschoarelli, Luis C
The aim of this study was to evaluate different handles used in axillary crutches with a Pressure Mapping System. The Grip Versatek system from Tekscan Inc. was used to measure the levels and the distribution of contact pressure in the hands during a simulated activity of ambulation with crutches. The sample included ten able-bodied subjects: five men and five women. The results show that the different models of handles appear to have influenced the pressure levels measured during the activity. Therefore, the measurement equipment provides parameters that allow the comparison among different designs and assess their contribution to the comprehension of the demands of ergonomic handles.
CHINESE women have now discovered that beautiful hands are realizable assets. A new career invites those with shapely hands: that of hand model. This nascent profession has great prospects, as images involving hands are essential in the advertising business for promotion of such products as jewelry, watches and cell phones. Certain film stars also employ standins for hand close-ups.
Full Text Available Eczema, the commonest disorders afflicting the hands, is also the commonest occupational skin disease (OSD. In the dermatology outpatient departments, only the severe cases are diagnosed since patients rarely report with early hand dermatitis. Mild forms are picked up only during occupational screening. Hand eczema (HE can evolve into a chronic condition with persistent disease even after avoiding contact with the incriminated allergen / irritant. The important risk factors for hand eczema are atopy (especially the presence of dermatitis, wet work, and contact allergy. The higher prevalence in women as compared to men in most studies is related to environmental factors and is mainly applicable to younger women in their twenties. Preventive measures play a very important role in therapy as they enable the affected individuals to retain their employment and livelihood. This article reviews established preventive and therapeutic options and newer drugs like alitretinoin in hand eczema with a mention on the etiology and morphology. Identifying the etiological factors is of paramount importance as avoiding or minimizing these factors play an important role in treatment.
Duncan, Nicole; Shih, A. Y.; Hurford, G. J.; Saint-Hilaire, P.; Bain, H.; Zoglauer, A.; Lin, R. P.; Boggs, S. E.
In two of the best-observed flares of the last cycle, the Reuven Ramaty High-Energy Solar Spectroscopic Imager (RHESSI) satellite found the centroids of ion and relativistic electron emission to have a significant displacement. This result is surprising; co-spatially accelerated ions and electrons are thought to be transported along the same field lines, implying they would enter the chromosphere together and have similar emission locations. The Gamma-Ray Imager/Polarimeter for Solar Flares (GRIPS) balloon instrument will investigate particle transport in solar flares by providing enhanced imaging, spectroscopy and polarimetry of gamma/HXR flare emission (20keV - 10MeV). GRIPS’ key technological improvements over the solar state of the art in HXR/gamma ray energies (RHESSI) include three-dimensional position-sensitive germanium detectors (3D-GeDs) and a single-grid modulating collimator, the multi-pitch rotating modulator (MPRM). The 3D-GeDs allow GRIPS to Compton track energy deposition within the crystal. This capability (1) enables the MPRM design by acting as a second modulation grid, (2) provides significant background rejection and (3) makes solar polarization measurements possible. The MPRM imager provides quasi-continuous resolution from 12.5 - 162 arcsecs with 2x the throughput of a dual grid collimator system like RHESSI. This spatial resolution can resolve the separate footpoints of many flare sizes. In comparison, RHESSI images with a minimum of 35 arcsecs for gamma-rays, making these footpoints resolvable in only the largest flares. Here, we present the intial calibration of GRIPS’ 3D-GED detectors using laboratory radioactive sources. We evaluate charge sharing between adjacent strips, the detection of coincidences and preliminary depth measurements. The detectors have been shown to have a linear response and resolve line emission. The MPRM modulation grid is constructed and we present initial results from calibration. GRIPS is scheduled for a
Egol, Kenneth A; Karia, Raj; Zingman, Allissa; Lee, Steve; Paksima, Nader
In order to identify predictors for hand stiffness following distal radius fractures and understand the consequences of this common clinical finding, we studied 260 patients. Our null hypothesis was that we would find no predictors of post injury hand stiffness. Baseline demographics and injury characteristics were obtained at distal radius fracture presentation. Treatment and healing was documented. Stiffness was defined as tip to palm distance greater than 1 cm for any one finger. Outcome parameters obtained at regular intervals included wrist and hand range of motion, radiographs, visual analog pain scales, and Disability of the Arm Shoulder and Hand (DASH) questionnaires. Forty-nine of 260 patients (19%) patients were considered to be "stiff" by our criteria. Grip strength was weaker for stiff patients as well. Patient demographics were similar in both groups with the "stiff" cohort having a greater mean age, p = 0.05. There was no significant difference in stiffness seen in operative cases versus nonoperative cases. Injury ulnar variance was 3.1mm (SD = 3.5) in the "stiff" cohort and 1.8 (SD = 2.9) in the "non-stiff" cohort (p= 0.02). Functional disability as measured by the DASH differed (p = 0.001) between stiff and non-stiff patients for both 6 month and 1 year follow-up time points. Stiff patients were more likely than non-stiff patients to have lower grip strength at 12-month post fracture (p = 0.001). Older patients who present with significant ulnar variance at injury are more likely to experience hand stiffness at some time during their recovery. The development of hand stiffness is associated with poorer functional outcome than those who do not develop stiffness.
Sassenrath, Claudia; Diefenbacher, Svenja; Siegel, André; Keller, Johannes
Adopting a social-psychological approach, this research examines whether emotional empathy, an affective reaction regarding another's well-being, fosters hand hygiene as this affects other's health-related well-being extensively. Three studies tested this notion: (a) a cross-sectional study involving a sample of health care workers at a German hospital, (b) an experiment testing the causal effect of empathy on hand hygiene behaviour and (c) an 11-week prospective study testing whether an empathy induction affected disinfectant usage frequency in two different wards of a hospital. Self-reported hand hygiene behaviour based on day reconstruction method was measured in Study 1, actual hand sanitation behaviour was observed in Study 2 and disinfectant usage frequency in two different hospital wards was assessed in Study 3. Study 1 reveals an association of empathy with hand hygiene cross-sectionally, Study 2 documents the causal effect of empathy on increased hand sanitation. Study 3 shows an empathy induction increases hand sanitiser usage in the hospital. Increasing emotional empathy promotes hand hygiene behaviour, also in hospitals. Besides providing new impulses for the design of effective interventions, these findings bear theoretical significance as they document the explanatory power of empathy regarding a distal explanandum (hand hygiene).
Ruoff, C. F.; Salisbury, J. K.
Mechanical joints and tendons resemble human hand. Robot hand has three "human-like" fingers. "Thumb" at top. Rounded tips of fingers covered with resilient material provides high friction for griping. Hand potential as prosthesis for humans.
Ghorbani, Azam; Shahrokhi, Akram; Soltani, Zahra; Molapour, Azam; Shafikhani, Mahin
This study was performed to compare the effects of two hand decontamination methods on the microbial burden of operating room staff hands. The surgical hand washing methods compared were a traditional surgical hand scrub using a povidone iodine solution, and a social wash using a liquid non-antibacterial soap followed by the application of an alcoholic hand rub.
Janssens, A Cecile J W; Ioannidis, John P A; van Duijn, Cornelia M; Little, Julian; Khoury, Muin J
• The rapid and continuing progress in gene discovery for complex diseases is fuelling interest in the potential application of genetic risk models for clinical and public health practice. • The number of studies assessing the predictive ability is steadily increasing, but the quality and completeness of reporting vary. • A multidisciplinary workshop sponsored by the Human Genome Epidemiology Network developed a checklist of 25 items recommended for strengthening the reporting of Genetic RIsk Prediction Studies (GRIPS), building on the principles established by prior reporting guidelines. • These recommendations aim to enhance the transparency of study reporting and thereby to improve the synthesis and application of information from multiple studies that might differ in design, conduct or analysis. • A detailed Explanation and Elaboration document is published as an accompanying article .
Rhythm Suren Wadhwa
Full Text Available Robot grippers are employed to position and retain parts in automated assembly operations. This paper presents an overview of electromagnet part handling framework in an iron foundry and an equivalent electromagnet circuit model. The manner in which this whole concept of automated gripping system operates will be discussed in this paper. The material handling system uses machine vision system coupled with conveyor motion and Ethernet communication strategy to assist the material handling system for transporting the foundry parts. The paper provides an overview of the electromagnet principles at play. The electromagnet interaction with the part is the key issue in the robust handling of this automated foundry system. This paper helps in the realization of the concept of automation in an iron foundry, in which the number of published studies is very limited.
Dahl-Jensen, Dorthe; Clausen, Henrik Brink; Taylor, K. C.
. Here we present electrical conductivity records for the Greenland Ice Sheet Project 2 (GISP2) and Greenland Ice-core Project (GRIP) ice cores, drilled 28 km apart to enable direct comparison of the results. The upper parts of both records are consistent with previous evidence from other Greenland cores......THE direct-current electrical conductivity of glacial ice depends on its acidity1-3, and can also indicate changes in climate, as ice formed in cold, dusty periods has a high concentration of alkaline dust1,4,5, which significantly reduces the conductivity6,7 compared to warmer, less dusty periods......4,8& #150;12 for a stable Greenland climate during the Holocene, and a series of warm events punctuating the last glacial period. However, there is a significant discrepancy between the two records in the bottom 10% of the cores, calling into question recent reports of climate variability...
The aim of the present study was to develop a relationship to evaluate grip force using the electromyogram (EMG) in isometric anisotonic conditions. The EMGs of the flexor digitorum superficialis (FDS) and the extensor digitorum (ED) were recorded in 3 flexion-extension positions of the wrist (30 degrees flexion, 30 degrees extension, and 60 degrees extension) associated with 3 positions of the forearm (70 degrees pronation, prono-supination, and 70 degrees supination). For each position, the participants had to follow linear ramp targets (2 rates of increase and decrease) displayed on an oscilloscope. The results show the best fit is a quadratic type force-EMG relationship. Some aspects such as the rate of force variation and the forearm and wrist positions are then discussed along with the limitations of the relationship.
Heymsfield, G. M.; Guimond, S. R.; Tian, L.
The dual-wavelength (Ku and Ka band) High-Altitude Imaging Wind and Rain Airborne Profiler (HIWRAP) flew for the first time on the Global Hawk during the 2010 Genesis and Rapid Intensification Processes (GRIP). HIWRAP is conical scanning and Doppler, and winds and reflectivity can be mapped within the swath below the Global Hawk. Two interesting cases from the HIWRAP flights were the rapid intensification of Hurricane Karl and the intensification of Tropical Storm Matthew. This presentation will highlight the precipitation and wind structure of these storms during their intensification as derived from the HIWRAP observations. If time permits and if available, highlights from HIWRAP observations from the Hurricane Severe Storm Sentinel (HS3) field campaign in September 2012 will be presented.
Bernard, Charlotte; Dabis, François; de Rekeneire, Nathalie
To present the current knowledge on physical function, grip strength and frailty in HIV-infected patients living in sub-Saharan Africa, where the phenomenon is largely underestimated. A systematic search was conducted on MEDLINE, Scopus and African Index Medicus. We reviewed articles on sub-Saharan African people living with HIV (PLHIV) >18 years old, published until November 2016. Of 537 articles, 12 were conducted in six African countries and included in this review. Five articles reported information on functional limitation and one on disability. Two of these five articles reported functional limitation (low gait speed) in PLHIV. Disability was observed in 27% and 3% of PLHIV living in rural and urban places, respectively. Two of three studies reporting grip strength reported lower grip strength (nearly 4 kg) in PLHIV in comparison with uninfected patients. One study reported that PLHIV were more likely to be frail than HIV-uninfected individuals (19.4% vs. 13.3%), whereas another reported no statistical difference. Decline in physical function, grip strength and frailty are now part of the burden of PLHIV living in SSA countries, but current data are insufficient to characterise the real public health dimension of these impairments. Further studies are needed to depict this major public health challenge. As this is likely to contribute to a significant burden on the African healthcare systems and human resources in the near future, a holistic care approach should be developed to inform guidelines. © 2017 John Wiley & Sons Ltd.
Tian, Lian; Henningsen, Joseph; Salick, Max R; Crone, Wendy C; Gunderson, McLean; Dailey, Seth H; Chesler, Naomi C
The mechanical properties of vascular tissues affect hemodynamics and can alter disease progression. The uniaxial tensile test is a simple and effective method for determining the stress-strain relationship in arterial tissue ex vivo. To enable calculation of strain, stretch can be measured directly with image tracking of markers on the tissue or indirectly from the distance between the grips used to hold the specimen. While the imaging technique is generally considered more accurate, it also requires more analysis, and the grip distance method is more widely used. The purpose of this study is to compare the stretch of the testing specimen calculated from the grip distance method to that obtained from the imaging method for canine descending aortas and large proximal pulmonary arteries. Our results showed a significant difference in stretch between the two methods; however, this difference was consistently less than 2%. Therefore, the grip distance method is an accurate approximation of the stretch in large elastic arteries in the uniaxial tensile test. Copyright © 2015 Elsevier Ltd. All rights reserved.
Tanggaard, Lene; Laursen, Dan Nørgaard; Szulevicz, Thomas
how balls made of synthetic polyurethane contribute to a better grip on the ball, which has led to new possibilities for attacking players in handball. The conclusion is that the leather handball is a mediating object, which co-creates the possibilities that the players have in expressing themselves...
Steenbergen, B.; Meulenbroek, R.G.J.; Rosenbaum, D.A.
This study was concerned with the selection criteria used for grip planning in adolescents with left or right hemiparetic cerebral palsy. In the first experiment participants picked up a pencil and placed the tip in a pre-defined target region. We varied the size of the target to test the hypothesis
Full Text Available Two-fingered micromanipulation systems with an integrated force sensor are widely used in robotics to sense and control gripping forces at the micro and nano-scales. They became of primary importance for an efficient manipulation and characterization of highly deformable biomaterials and nanostructures. This paper presents a chronological overview of gripping force measurement using two-fingered micromanipulation systems. The work summarizes the major achievements in this field from the early 90s to the present, focusing in particular on the evolution of measurement technologies regarding the requirements of microrobotic applications. Measuring forces below the microNewton for the manipulation of highly deformable materials, embedding force sensors within microgrippers to increase their dexterity, and reducing the influence of noise to improve the measurement resolution are among the addressed challenges. The paper shows different examples of how these challenges have been addressed. Resolution, operating range and signal/noise ratio of gripping force sensors are reported and compared. A discussion about force measurement technologies and gripping force control is performed and future trends are highlighted.
Shang, Xiaoxin; Veldhuis, Raymond N.J.
In the biometric verification system of a smart gun, the rightful user of a gun is recognized based on grip-pattern recognition. It was found that the verification performance of this system degrades strongly when the data for training and testing have been recorded in different sessions with a time
Full Text Available Two-fingered micromanipulation systems with an integrated force sensor are widely used in robotics to sense and control gripping forces at the micro and nano-scales. They became of primary importance for an efficient manipulation and characterization of highly deformable biomaterials and nanostructures. This paper presents a chronological overview of gripping force measurement using two-fingered micromanipulation systems. The work summarizes the major achievements in this field from the early 90s to the present, focusing in particular on the evolution of measurement technologies regarding the requirements of microrobotic applications. Measuring forces below the microNewton for the manipulation of highly deformable materials, embedding force sensors within microgrippers to increase their dexterity, and reducing the influence of noise to improve the measurement resolution are among the addressed challenges. The paper shows different examples of how these challenges have been addressed. Resolution, operating range and signal/noise ratio of gripping force sensors are reported and compared. A discussion about force measurement technologies and gripping force control is performed and future trends are highlighted.
The coefficient of variation (CV) is commonly used to detect sincerity of effort. The purpose of this study was to examine whether the CV possessed adequate sensitivity and specificity to effectively detect sincerity of effort of grip strength. One hundred forty-six uninjured volunteers underwent a series of grip strength tests. Sensitivity and specificity values were calculated for various CV cut-off values (between 2.5% and 22%) of the static grip test. The receiver operating characteristic (ROC) curves based on these values demonstrated the trade-offs between specificity and sensitivity. For example, the "traditional" 15% cut-off value yielded poor sensitivity (0.55), whereas the 11% cut-off value yielded poor specificity (0.74). Selecting any cut-off value along the continuum did not provide adequate sensitivity or specificity for labeling an effort sincere or insincere. Although the CV differentiated between maximal and submaximal effort, it was not sensitive or specific enough to do so effectively. Thus, the CV should not be used to assess sincerity of effort of grip strength.
Montagnat, M.; Azuma, N.; Dahl-Jensen, D.; Eichler, J.; Fujita, S.; Gillet-Chaulet, F.; Kipfstuhl, S.; Samyn, D.; Svensson, A.; Weikusat, I.
Fabric (distribution of crystallographic orientations) along the full NEEM ice core, Greenland was measured in the field by an automatic ice texture analyzer every 10 m, from 33 m down to 2461 m depth. The fabric evolves from a slightly anisotropic fabric at the top, toward a strong single maximum at about 2300 m, which is typical of a deformation pattern mostly driven by uniaxial compression and simple shearing. A sharp increase in the fabric strengthening rate is observed at the Holocene to Wisconsin (HW) climatic transition. From a simple model we estimate that this depth is located at a transition from a state dominated by vertical compression to a state dominated by vertical shear. Comparisons are made to two others ice cores drilled along the same ridge; the GRIP ice core, drilled at the summit of the ice sheet, and the NGRIP ice core, drilled 325 km to the NNW of the summit along the ridge, and 365 km upstream from NEEM. This comparison tends to demonstrate that the ice viscosity change with the HW climatic transition must be associated with the shear-dominated state to induce the abrupt fabric strengthening observed at NEEM. This comparison therefore reflects the increasing role of shear deformation on the coring site when moving NW along the ridge from GRIP to NGRIP and NEEM. The difference in fabric profiles between NEEM and NGRIP also evidences a stronger lateral extension associated with a sharper ridge at NGRIP. Further along the core, centimeter scale abrupt texture (fabric and microstructure) variations are observed in the bottom part of the core. Their positions are in good agreement with the observed folding layers in Dahl-Jensen et al. (2013).
Li, Yong; Randerath, Jennifer; Goldenberg, Georg; Hermsdörfer, Joachim
The prediction of object weight from its size is an important prerequisite of skillful object manipulation. Grip and load forces anticipate object size during early phases of lifting an object. A mismatch between predicted and actual weight when two different sized objects have the same weight results in the size-weight illusion (SWI), the small object feeling heavier. This study explores whether lateralized brain lesions in patients with or without apraxia alter the size-weight illusion and impair anticipatory finger force scaling. Twenty patients with left brain damage (LBD, 10 with apraxia, 10 without apraxia), ten patients with right brain damage (RBD), and matched control subjects lifted two different-sized boxes in alternation. All subjects experienced a similar size-weight illusion. The anticipatory force scaling of all groups was in correspondence with the size cue: higher forces and force rates were applied to the big box and lower forces and force rates to the small box during the first lifts. Within few lifts, forces were scaled to actual object weight. Despite the lack of significant differences at group level, 5 out of 20 LBD patients showed abnormal predictive scaling of grip forces. They differed from the LBD patients with normal predictive scaling by a greater incidence of posterior occipito-parietal lesions but not by a greater incidence of apraxia. The findings do not support a more general role for the motor-dominant left hemisphere, or an influence of apraxia per se, in the scaling of finger force according to object properties. However, damage in the vicinity of the parietal-occipital junction may be critical for deriving predictions of weight from size.
García Ureña, M Á; Hidalgo, M; Feliu, X; Velasco, M Á; Revuelta, S; Gutiérrez, R; Utrera, A; Porrero, J L; Marín, M; Zaragoza, C
Investigation in the field of inguinal hernia surgery is now focused on postoperative pain. The extended use of lightweight meshes and alternative methods of fixation may play a relevant role in the reduction of pain. In this study, a new self-gripping lightweight polypropylene mesh is tested. A multicentric, observational study was scheduled to prospectively evaluate this new mesh. Ten centers agreed to participate. Only primary, type 1 or 2 uncomplicated hernias in adults were included. The mesh was placed as a Lichtenstein procedure without any fixation. A complete pain questionnaire was followed at 1 week, and at 1, 3 and 6 months postoperatively. The principal goal of the study was to evaluate maximum pain score at 6 months. Pain was assessed by a visual analog scale. A total of 256 patients were operated. Mean operative time was 35.6 min; 76.2% of patients were operated in an ambulatory setting. There were a few postoperative complications: 2 wound infections, 17 seromas, 21 hematomas, 6 orchitis. The incidence of acute pain was 27.3% at week 1 and 7.5% at month 1. The incidence of chronic pain was 3.6% at month 3 and 2.8% at month 6. No recurrences or long-term complications were observed. This self-gripping mesh can be used safely in type 1 and 2 primary, uncomplicated inguinal hernia with minimal morbidity and most patients under ambulatory setting. The registered incidence of chronic pain is lower than 3%.
Full Text Available Background & Purpose: Lateral epicondylitis is the most common lesion of the elbow. Tennis elbow or lateral epicondylitis is defined as a syndrome of pain in the wrist extensor muscles at or near their lateral epicondyle origin or pain directly over the lateral epicondyle. So, the aim of this study was to compare the effectiveness of Active Release Technique (ART and Myofascial Release Technique (MFR in the treatment of Chronic Lateral Epicondylitis (CLE. Methodology: The study included thirty-six patients with Chronic Lateral Epicondylitis of age group range between 30 to 45 years. Patients were randomly divided into three groups: Control Group (A, Active Release Technique Group (B and Myofascial Release Technique Group (C. The patients were treated for 4 weeks and three outcome measures: 0-10 NPRS, Hand Dynamometer and PRTEE were taken for assessment and analysis at baseline and after 4th weeks was done. Result: In this study the result showed that Active Release Technique and Myofascial Release Technique were effective in all three outcome measures when compared to Control Group. Myofascial Release Technique was more effective in improving grip strength & reducing pain & disability when compared to Active Release Technique.(p<0.05 Conclusion: Active Release Technique and Myofascial Release Technique are effective in patients with Chronic Lateral Epicondylitis. Myofascial Release Technique demonstrated better outcomes than Active Release Technique in the management of Chronic Lateral Epicondylitis.
This video shows kids how to properly wash their hands, one of the most important steps we can take to avoid getting sick and spreading germs to others. Created: 3/8/2010 by Centers for Disease Control and Prevention (CDC). Date Released: 3/8/2010.
Full Text Available ... practice hand hygiene in hospitals and other healthcare facilities. Release Date: 8/4/2010 Source: Healthcare-associated ... choose "Save target as…", save file in desired location. Firefox/Chrome: Right-click on the link, choose " ...
Full Text Available ... CDC-TV videos cover a variety of health, safety and preparedness topics and include closed-captioning. Videos are prepared for different audiences including, children, parents, and public health professionals. More > Hand Hygiene Saves Lives (5:10) Recommend on Facebook Tweet ...
De hand van Huizinga bevat een nieuwe selectie van de belangrijkste essays uit het omvangrijke oeuvre van de wereldberoemde Nederlandse historicus Johan Huizinga. Deze essays en studies zijn geselecteerd op basis van de diverse disciplines waarmee Huizinga zich bezighield - van de Middeleeuwen tot
PUPPETRY n ancient artform, has had difficulties ca-tering to children’s aesthet-ic needs and perceptions.ShanghaiHand Puppet Troupe has,however,successfully reached children audi-ences with its new science fictlonpiece,Nuozha Meets the Inhabitants of Tai star.
Mathews, Catherine E.; Monroe, Louise Nelson
A professional school and university collaboration enables elementary students and their teachers to explore hydrology concepts and realize the beneficial functions of wetlands. Hands-on experiences involve young students in determining water quality at field sites after laying the groundwork with activities related to the hydrologic cycle,…
Soltanian, Hooman; de Bese, Genevieve; Beasley, Robert W
For many mangled hands, appropriately designed passive prostheses now available, alone or in conjunction with surgical reconstruction, can offer the best available improvement, provided they are of high quality and backed by prompt and reliable after-delivery services. Invariably, there is improvement in physical capability along with restoration of good social presentation.
In this podcast, learn how to help stop the spread of infection and stay healthy. It's easy when you 'Put Your Hands Together.'. Created: 3/24/2011 by National Center for Preparedness, Detection, and Control of Infectious Diseases (NCPDCID) and National Center for Zoonotic, Vector-Borne, and Enteric Diseases (NCZVED). Date Released: 3/24/2011.
J.C.H.M. van der Meulen (Jacques)
textabstractIntroduction: In a world where mechanisation and automation have led to a devaluation of skilled manual work, and where only certain press and publicity media doubt the superiority of the mind, the following operating-theatre dialogue is refreshing: Surgeon: The surgeon's hands are his f
Mathews, Catherine E.; Monroe, Louise Nelson
A professional school and university collaboration enables elementary students and their teachers to explore hydrology concepts and realize the beneficial functions of wetlands. Hands-on experiences involve young students in determining water quality at field sites after laying the groundwork with activities related to the hydrologic cycle,…
Norton, William E.; Belcher, Jewell G., Jr.; Carden, James R.; Vest, Thomas W.
Prosthetic hand attached to end of remaining part of forearm and to upper arm just above elbow. Pincerlike fingers pushed apart to degree depending on rotation of forearm. Simpler in design, simpler to operate, weighs less, and takes up less space.
Bishop, Lauri; Gordon, Andrew M; Kim, Heakyung
The aim of this study was to understand the impact of training with a hand robotic device on hand paresis and function in a population of children with hemiparesis. Twelve children with hemiparesis (mean age, 9 [SD, 3.64] years) completed participation in this prospective, experimental, pilot study. Participants underwent clinical assessments at baseline and again 6 weeks later with instructions to not initiate new therapies. After these assessments, participants received 6 weeks of training with a hand robotic device, consisting of 1-hour sessions, 3 times weekly. Assessments were repeated on completion of training. Results showed significant improvements after training on the Assisting Hand Assessment (mean difference, 2.0 Assisting Hand Assessment units; P = 0.011) and on the upper-extremity component of the Fugl-Meyer scale (raw score mean difference, 4.334; P = 0.001). No significant improvements between pretest and posttest were noted on the Jebsen-Taylor Test of Hand Function, the Quality of Upper Extremity Skills Test, or the Pediatric Evaluation of Disability Inventory after intervention. Total active mobility of digits and grip strength also failed to demonstrate significant changes after training. Participants tolerated training with the hand robotic device, and significant improvements in bimanual hand use, as well as impairment-based scales, were noted. Improvements were carried over into bimanual skills during play. Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME OBJECTIVES: Upon completion of this article, the reader should be able to: (1) Understand key components of neuroplasticity; (2) Discuss the benefits of robotic therapy in the recovery of hand function in pediatric patients with hemiplegia; and (3) Appropriately incorporate robotic therapy into the treatment plan of pediatric patients with hemiplegia. Advanced ACCREDITATION: The Association of Academic Physiatrists is accredited by the