Impact of elbow position on grip strength of elderly men

Young basketball players have better manual dexterity performance than sportsmen and non-sportsmen of the same age: a cross-sectional study

Manual dexterity is a key skill in motor development. There are conflicting studies on the influence of sports practice on this skill and on which type of sport trains this ability the most in youth. Manual dexterity is usually assessed with expensive and time-consuming tools not easily available to facilities such as schools or sports clubs. The aim of this study was to assess differences in manual dexterity performance between young basketball players, sportsmen, and non-sportsmen. A further aim was to analyze whether the coin rotation task was a reliable tool for assessing manual dexterity. Based on the characteristics of the sport, we hypothesized that basketball players had better manual dexterity performances. Seventy-eight participants were included in the study and categorized into "basketball", "sports", and "non-sports" groups. Manual dexterity was assessed with the grooved pegboard, the coin rotation task, and the handgrip tests. The basketball group showed better performance in all tests. Significant differences were found between the basketball group and sports group and between the basketball group and non-sport group in the grooved pegboard (p < 0.05) and in the handgrip (p < 0.05) tests. Test-retest reliability of the coin rotation task scores was moderate in the basketball group (ICC2,1 0.63-0.6). Basketball practice could positively influence manual dexterity. The coin rotation task showed an acceptable construct of validity.

Predicting the handgrip strength across the age span: Cross-validating reference equations from the 2011 NIH toolbox norming study

STUDY DESIGN

This is a cross-sectional observational study.

BACKGROUND

Reference equations for describing hand-grip strength across the age span were derived from the 2011 NIH Toolbox norming study.

PURPOSE

The purpose of this study was to cross-validate reference equations by evaluating its predicting power on a separate, independent data set from the 2011-2014 National Health and Nutrition Examination Survey (NHANES) study METHODS: Observed hand-grip strength data from 13,676 noninstitutionalized participants were obtained from the NHANES study. Best values (best from 3 trials) and the mean values (averaged from 3 trials) were determined for each hand. Using the age (yr), height (m), and weight (kg), we computed predicted grip strength values for dominant and nondominant hands using the reference equations. For validation, three predictability measures: the correlation coefficient, residuals, and accuracy, were used along with the Bland-Altman plot.

RESULTS

The predicted values highly correlated with observed values (r = 0.90, ICC = 0.89). In predicting best values, means (SD) of residuals were 1.41 (5.57) and 1.03 (5.44) kg for dominant and nondominant hands, respectively. In predicting mean values, means (SD) of residuals were -0.23 (5.42) and -0.54 (5.31) kg for dominant and nondominant hands, respectively. Root mean square error ranged from 4.10 (female's nondominant mean values) to 6.74 (male's dominant best values). About 5.56% fell outside of the 95% confidence interval of the prediction.

CONCLUSIONS

We acknowledged that the two studies' hand-grip protocols (NIH Toolbox, NHANES) were different. Results provided the preliminary predicting performance of the reference equations derived from the NIH Toolbox study.

The Effect of Posture on Maximum Grip Strength Measurements

INTRODUCTION/BACKGROUND

The purpose of this study was to compare the grip strength values obtained under 4 postures, and to identify the position providing the maximum grip strength value. We also explored the effects of different body positions on grip strength measurements and the significance of the selection of measurement position for guiding the screening and diagnosis of sarcopenia.

METHODOLOGY

A total of 764 people (409 males and 355 females) participated in this study. Grip strength was measured in 4 positions: (1) standing with the elbow fully extended; (2) standing with arms raised; (3) sitting with the elbow flexed 90°; and (4) sitting with the elbow extended. Multiple linear regression model was used to compare the grip strength measurements obtained from these 4 positions by each hand when considering the influence of age, gender, body mass index, and other factors.

RESULTS

Both male and female grip strength values in the standing position with the elbow fully extended were significantly greater than those in other positions. In addition, the grip strength measured by standing posture was generally greater than measured by sitting posture. In contrast, grip strength values in the 2 sitting positions did not differ significantly. The grip strength of men was generally greater than that of women.

CONCLUSIONS

The findings reveal that grip strength measured while standing with the elbow fully extended is greater than that measured while sitting, which is the posture currently recommended in clinical practice. Clinicians and researchers should choose the appropriate and optimal postures to measure grip strength.

Physical Function and Survival in Older Adults: A longitudinal study accounting for time-varying effects

PURPOSE OF THE STUDY

Variation in physical function in older adults over time raises several methodological challenges in the study of its association with survival, many of which have largely been overlooked in previous studies. The objective of this study is to examine the relationship between time-varying measures of physical function and survival in men and women aged 70 years and over, while accounting for the time-varying effects of health and lifestyle characteristics.

METHODS

1,846 women and 1,245 men in the Cardiovascular Health Study followed annually for up to 10 years beginning at age 70-74 years were included. We estimated the effect of gait speed and grip strength on survival over the subsequent year, using age as the timescale.

RESULTS

A 0.1m/s higher gait speed was associated with a 12% decrease in the likelihood of death in the subsequent year among women (HR 0.88, 95% CI 0.82-0.94). There was no statistically significant effect of gait speed on survival among men (HR 0.97, 95% CI 0.91 to 1.03), or of grip strength on survival among women (HR 0.97, 95% CI 0.95-1.00) or men (HR 0.99, 95% CI 0.97-1.01), over one year.

CONCLUSIONS

Upon using time-varying measures of physical function while accounting for time-varying effects of health and lifestyle characteristics, higher gait speed was associated with increased survival among the women in our study. We found no evidence of an association between gait speed and one-year survival in men, or between grip strength and one-year survival in women or men.

Upper limb position affects pain-free grip strength in individuals with lateral elbow tendinopathy

BACKGROUND AND PURPOSE

Pain-free grip (PFG) force is commonly used to monitor treatment outcomes in lateral elbow tendinopathy (LET); however, it is unclear whether changes in forearm and elbow position affect PFG force values. This study aims to examine the effect of elbow/shoulder and forearm position on non-normalised and normalised PFG force in individuals with unilateral LET.

METHODS

A cohort study including 21 subjects with clinically diagnosed unilateral LET (13 females, mean [SD] age 50 [8] years) performed PFG force (symptomatic arm) and maximal grip (asymptomatic arm) tasks using four upper limb positions: (1) shoulder neutral, elbow flexed (90°), forearm pronated; (2) shoulder neutral, elbow flexed (90°), forearm neutral; (3) shoulder flexed (90°), elbow extended, forearm pronated; and (4) shoulder flexed (90°), elbow extended, forearm neutral. PFG force was normalised to the maximal grip of the asymptomatic side. Repeated-measures analyses of variance were used to compare non-normalised and PFG force normalised to maximal grip between positions.

RESULTS

Both non-normalised and normalised PFG forces were greater in position 2 than position 1, position 3 and position 4 (elbow-by-forearm interaction non-normalised p = 0.002, normalised p = 0.004). There were no differences between positions 1, 3 and 4 for either non-normalised or normalised PFG strength.

DISCUSSION

This study shows that PFG force was higher when performed with forearm neutral supination/pronation, elbow flexion and shoulder neutral than other tested positions, and irrespective of whether PFG force was normalised to the maximal grip force of the contralateral limb. This indicates that arm position should be standardised for comparison.

Effects of a power strength training using elastic resistance exercises on the motor and non-motor symptoms in patients with Parkinson's disease H&Y 1-3: study protocol for a randomised controlled trial (PARK-BAND Study)

INTRODUCTION

Parkinson's disease (PD) is the second most common neurodegenerative disorder in Brazil. Physical activity is a complementary intervention in managing inherent declines associated with the disease like strength, balance, gait, and functionality and benefit health-related outcomes. Here, we report the PARK-BAND Study protocol, which aims to investigate potential benefits of power training using elastic devices in participants with PD. Our intervention will be provided in patients with PD using elastic devices like elastic bands and tubes. Therefore, we used the term Park from Parkinson's disease and band from elastic bands.

METHODS AND ANALYSIS

This randomised single-blind single-centre two-arm parallel, superiority trial will include 50 participants with PD attending the clinical setting. Those who meet the eligibility criteria and provide consent to participate will be randomised in a 1:1 ratio to either the exercise group, which will receive power training programme or the health education group, which will receive the education programme. Randomisation will be performed by permuted block randomisation with a block size of eight. Both groups will receive a 12-week intervention. The exercise group will have two sessions per week and the health education group will have one session per week. Changes from baseline in bradykinesia, as assessed by the Unified Parkinson's Disease Rating Scale motor examination subscore and physical functional performance, will be the primary outcomes. Secondary outcomes include other neurological, neurophysiological and physical variables, as well as the quality of life, depression, cognition, sleep quality and disturbances, assessed before and after interventions. We hypothesise that the exercise group will have greater improvement in primary and secondary outcomes than the health education group.

ETHICS AND DISSEMINATION

The study is approved by the Research Ethics Committee of Hospital Universitário Walter Cantidio and all participants will provide their written informed consent (register number 91075318.1.0000.5045).Trial results will be disseminated via peer reviewed journal articles and conference presentations, reports for organisations involved with PD and for participants.

TRIAL REGISTRATION NUMBER

Registro Brasileiro de Ensaios Clínicos Registry (RBR-5w2sqt); Pre-results.

Summary of grip strength measurements obtained in the 2011-2012 and 2013-2014 National Health and Nutrition Examination Surveys

STUDY DESIGN

Cross-sectional and descriptive study.

INTRODUCTION

Supported by the Centers for Disease Control and Prevention, the National Health and Nutrition Examination Survey (NHANES) began collecting grip strength data from nationally representative samples in 2011.

PURPOSE OF THE STUDY

To examine the stability of the grip strength values across 2 data release cycles and provide updated US population-based grip strength values for 6 to 80 year olds.

METHODS

Handgrip data from 13,676 participants aged 6-80 years were extracted from the NHANES 2011-2014 database. The muscle strength/grip test component measured the isometric grip strength using a Takei digital handgrip dynamometer (Takei Scientific Instruments, Shinagawa-Ku, Tokyo). Grip strength values (best of 3 trials for each hand) were summarized by gender, dominant side, and age group. Grip data from 2 data release cycles (2011-2012 vs 2013-2014) were compared.

RESULTS

Differences between 2 data release cycles were negligible. Hence, we summarize grip strength values across the entire 2011-2014 period. The mean grip strength ranged from 50.3 kg for the dominant hand of 30- to 34-year-old men to 10.0 kg for the nondominant hand of 6-year-old girls.

DISCUSSION

The summary data we present provide relatively current reference values to which tested individuals can be compared. However, clinicians and/or researchers should be aware that the instrumentation and procedures may influence the values.

CONCLUSIONS

Results supported the stability of the NHANES grip strength values across data release cycles.

Handgrip Strength: A Comparison of Values Obtained From the NHANES and NIH Toolbox Studies

IMPORTANCE

Handgrip dynamometry is probably the most commonly used method to characterize overall human muscle strength.

OBJECTIVE

To compare and summarize grip strength measurements obtained from two population-based studies.

DESIGN

Secondary data analysis.

SETTING AND PARTICIPANTS

Data from (1) the 2011-2014 National Health and Nutrition Examination Survey (NHANES) with 13,918 participants and (2) the 2011 normative phase of the National Institutes of Health (NIH) Toolbox project with 3,594 participants.

OUTCOMES AND MEASURES

The NHANES values used were the mean and best of three trials; the NIH Toolbox value used was the one maximum trial after a practice trial.

RESULTS

General linear model analysis revealed that values obtained from the NIH Toolbox differed from NHANES best values but not from NHANES mean values. The analysis also indicated, regardless of the values used, that grip strength differed significantly between dominant and nondominant sides, males and females, and age groups. We provide updated reference values for handgrip strength.

CONCLUSIONS AND RELEVANCE

On the basis of these analyses, we summarize grip strength measures obtained from the NHANES and NIH Toolbox for side, gender, and age group strata. Reference values are essential to assist in the interpretation of testing results and clinical decision making.

CORP: Measurement of upper and lower limb muscle strength and voluntary activation

Muscle strength, the maximal force-generating capacity of a muscle or group of muscles, is regularly assessed in physiological experiments and clinical trials. An understanding of the expected variation in strength and the factors that contribute to this variation is important when designing experiments, describing methodologies, interpreting results, and attempting to replicate methods of others and reproduce their findings. In this review (Cores of Reproducibility in Physiology), we report on the intra- and inter-rater reliability of tests of upper and lower limb muscle strength and voluntary activation in humans. Isometric, isokinetic, and isoinertial strength exhibit good intra-rater reliability in most samples (correlation coefficients ≥0.90). However, some tests of isoinertial strength exhibit systematic bias that is not resolved by familiarization. With the exception of grip strength, few attempts have been made to examine inter-rater reliability of tests of muscle strength. The acute factors most likely to affect muscle strength and serve as a source of its variation from trial-to-trial or day-to-day include attentional focus, breathing technique, remote muscle contractions, rest periods, temperature (core, muscle), time of day, visual feedback, body and limb posture, body stabilization, acute caffeine consumption, dehydration, pain, fatigue from preceding exercise, and static stretching >60 s. Voluntary activation, the nervous system’s ability to drive a muscle to create its maximal force, exhibits good intra-rater reliability when examined with twitch interpolation (correlation coefficients >0.80). However, inter-rater reliability has not been formally examined. The methodological factors most likely to influence voluntary activation are myograph compliance and sensitivity; stimulation location, intensity, and inadvertent stimulation of antagonists; joint angle (muscle length); and the resting twitch.

Hand grip strength in patients with chronic obstructive pulmonary disease

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 HGS test could be used as a marker of QoL in patients with COPD and could assist risk stratification in clinical practice.

[Measuring the handgrip strength of geriatric patients]

The handgrip strength of geriatric patients can be measured when the patient is hospitalized. This article elaborates on the intrinsic and extrinsic factors which have a direct or indirect influence on handgrip strength. For the best results the tests need to be taken in the best circumstances with attention to individual differences and the age of the patient. Handgrip strength as determination of biological vitality is a key concept. Besides the physical characteristics there are many psychological factors (cognition, psyching-up, test attitude…) influencing the results. These are barely mentioned or not mentioned at all in the usual procedures. Research of handgrip strength testing theories is mostly focused on young, healthy adults and less on elderly patients. The main goal of this article is stimulating experimental research on the measurement of handgrip strength with elderly people and involving them more actively with the procedure. It is not enough to acquire insight in function and predicting characteristics of handgrip strength. Next to the aiming for the best test performance is 'working interactively with elderly patients' a goal on itself in the modern vision of health care.

Effects of the resting time associated with the number of trials on the total and individual finger forces in a maximum grasping task

The repetitive and excessive workload accompanying grip strength- or hand-intensive tasks are often considered to be common causes of work-related upper limb musculoskeletal disorders. For this reason, numerous experimental studies have been performed on maximum grip strength. However, due to an absence of standard guidelines, researchers have adopted different resting times and number of trials suited for their particular research purposes. The effects of resting time and the number of trials on the maximum total grip strength and individual finger forces of 24 participants over 20 trials were investigated. Results showed that the total grip strength and individual finger strengths differed significantly according to the resting time and the number of trials (p<0.05). Overall, grip strength tended to increase with a reduction in resting time (% reduction: 7.8%, 9.1%, 11.1%, and 13.0% for 3 min, 2 min, 1 min, and 30s resting time, respectively) as well as with an increase in the number of trials (% reduction: 8%, 10%, 13%, and 16% for 5th, 10th, 15th, and 20th trials). The effects of resting time and the number of trials also showed statistically significant effects on individual finger forces. Regression equations of total grip strength and finger forces with resting time and number of trials were established. These equations were then applied to formulate guidelines for appropriate resting times in experiments based on the number of trials and acceptable reductions in grip strength. Data from this and future studies regarding decreasing grip strength and the contribution of each finger are expected to form the groundwork for ergonomic hand tool design and development.

Physical strength is associated with Mini-Mental State Examination scores in Spanish institutionalized elderly

AIM

The present cross-sectional study aimed at assessing muscle strength of hands, the dominant arm and legs in Spanish institutionalized elderly people according to sex, age and cognitive status.

METHODS

A total of 153 elderly subjects (102 females, 51 males, mean age 83.6 ± 6.8 years) living in the region of Madrid were measured for handgrip strength (kg) with a Takei TKK 5101 digital dynamometer (range 5-100 kg, precision 0.1 kg), and arm and leg endurance strength (repetitions) according to the Rikli and Jones tests. Cognitive status was determined with the Mini-Mental State Examination (MMSE).

RESULTS

The values for men and women were, respectively: 23.5 ± 7.3 kg and 11.6 ± 4.6 kg (right handgrip), 22.0 ± 7.8 kg and 10.7 ± 4.8 kg (left handgrip), 13 ± 5 and 10 ± 5 repetitions (arm strength), 8 ± 5 and 5 ± 4 repetitions (legs strength), and 21 ± 6 and 17 ± 7 (MMSE score). All parameters were significantly higher for men (P ≤ 0.01), but strength decline with age was less pronounced in women. In all MMSE groups, lower strength was associated with lower cognitive status.

CONCLUSIONS

Strength values were lower in older subjects in both sexes; this difference was higher in men than in women. Higher strength values were associated with better cognitive status, which was the most influencing variable, even more than sex and age.

Effect of sensory feedback from the proximal upper limb on voluntary isometric finger flexion and extension in hemiparetic stroke subjects

This study investigated the potential influence of proximal sensory feedback on voluntary distal motor activity in the paretic upper limb of hemiparetic stroke survivors and the potential effect of voluntary distal motor activity on proximal muscle activity. Ten stroke subjects and 10 neurologically intact control subjects performed maximum voluntary isometric flexion and extension, respectively, at the metacarpophalangeal (MCP) joints of the fingers in two static arm postures and under three conditions of electrical stimulation of the arm. The tasks were quantified in terms of maximum MCP torque [MCP flexion (MCP(flex)) or MCP extension (MCP(ext))] and activity of targeted (flexor digitorum superficialis or extensor digitorum communis) and nontargeted upper limb muscles. From a previous study on the MCP stretch reflex poststroke, we expected stroke subjects to exhibit a modulation of voluntary MCP torque production by arm posture and electrical stimulation and increased nontargeted muscle activity. Posture 1 (flexed elbow, neutral shoulder) led to greater MCP(flex) in stroke subjects than posture 2 (extended elbow, flexed shoulder). Electrical stimulation did not influence MCP(flex) or MCP(ext) in either subject group. In stroke subjects, posture 1 led to greater nontargeted upper limb flexor activity during MCP(flex) and to greater elbow flexor and extensor activity during MCP(ext). Stroke subjects exhibited greater elbow flexor activity during MCP(flex) and greater elbow flexor and extensor activity during MCP(ext) than control subjects. The results suggest that static arm posture can modulate voluntary distal motor activity and accompanying muscle activity in the paretic upper limb poststroke.

Effect of handrail shape on graspability

This paper summarizes research performed to evaluate the impact of handrail profile dimensions on graspability. It reports on research performed to determine the forces that stairway users exert on handrails when they fall, tests demonstrating the forces persons with various hand sizes can exert on handrails with different profiles, and comparisons of the probability of loss of grip by stairway users when they attempt to arrest a fall by grasping a handrail. The recommendations based on this work include specific definitions of the shapes of handrails that are deemed to be sufficiently graspable to constitute functional handrails.

Age- and gender-specific normative data of grip and pinch strength in a healthy adult Swiss population

Assessment of hand strength is used in a wide range of clinical settings especially during treatment of diseases affecting the function of the hand. This investigation aimed to determine age- and gender-specific reference values for grip and pinch strength in a normal Swiss population with special regard to old and very old subjects as well as to different levels of occupational demand. Hand strength data were collected using a Jamar dynamometer and a pinch gauge with standard testing position, protocol and instructions. Analysis of the data from 1023 tested subjects between 18 and 96 years revealed a curvilinear relationship of grip and pinch strength to age, a correlation to height, weight and significant differences between occupational groups. Hand strength values differed significantly from those of other populations, confirming the thesis that applying normative data internationally is questionable. Age- and gender-specific reference values for grip and pinch strength are presented.

Effect of elbow position on grip strength in the evaluation of lateral epicondylitis

PURPOSE

This study evaluated the maximum grip strength in a position of elbow extension versus flexion as a diagnostic tool in the assessment of a patient with suspected lateral epicondylitis (LE).

METHODS

From our database we identified 81 patients with grip strength measurements and the diagnosis of LE. From these patient records we collected grip strength measurements with the elbow in full extension and with the elbow in 90 degrees of flexion for the affected and the healthy extremity. We then compared 2 values: the pretreatment grip strength in flexion and extension for the affected extremity and the pretreatment grip strengths of the nonaffected extremity compared with the affected extremity. Grip strengths were compared with paired and unpaired 2-tailed t tests.

RESULTS

Grip strength was no different in flexion and extension for the healthy extremity and 29% stronger in flexion than in extension for the affected extremity. The affected arm averaged 50% of the strength of the healthy arm in extension and 69% of the strength of the healthy arm in flexion. These differences were statistically significant. An 8% difference in grip strength between flexion and extension was found to be 83% accurate in distinguishing the affected from the unaffected extremities.

CONCLUSIONS

The measurement of extension grip strength is a useful objective tool to aid in the diagnosis of LE. In patients with LE, the grip strength decreases as one moves from a position of flexion to a position of extension.

Comparison of pressure pain threshold, grip strength,dexterity and touch pressure of dominant and non-dominant hands within and between right-and left-handed subjects

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.

Grip Strength in the Frail Elderly

OBJECTIVE

To explore the relationship of impairment types to grip strength in the live-at-home frail elderly.

DESIGN

All data in this cross-sectional study were collected in face-to-face interviews in subjects' homes by a nurse or occupational therapist. A total of 832 elders with activity limitations, as determined by the FIM instrument, participated in the study. Subjects were divided into three age groups (60-69, 70-79, and 80+ yrs) and four impairment groups: (1) minimally impaired, (2) visually impaired, (3) motor impaired, and (4) cognitively impaired. The outcome measures included the average (in kilograms) of three grip-strength trials per hand measured with the Jamar dynamometer at the second handle setting.

RESULTS

There were significant differences in grip strength scores among all age groups, indicating that grip strength decreased with age. Among impairment groups, the minimally impaired and visually impaired groups had significantly greater grip strength scores than the motor-impaired and the cognitively impaired groups. There were no significant differences between the minimally impaired and visually impaired groups or between the motor-impaired and the cognitively impaired groups.

CONCLUSIONS

Age and sex are not the only determining factors of grip strength in the frail elderly. The type of impairment affects grip strength as well. Thus, age-based norms may not be the only basis for interpreting evaluation data and establishing treatment goals with this population.

The influence of wrist position on individual finger forces during forceful grip

Nine healthy subjects sustained maximum grip of an instrumented handle while voluntarily moving the wrist joint within their available range of motion of the wrist in a continuous and random manner. Individual finger forces and wrist angular positions in flexion/extension and radial/ulnar deviation were recorded simultaneously. Wrist position had a significant effect on individual finger force and total force production. Peak finger forces were produced at 20 degrees of wrist extension and 5 degrees of ulnar deviation. At this position, a mean total grip force of 114.9 (+/-12.8) N was produced with force-sharing percentages of 32.2% (+/-3.8%), 32.6% (+/-4.3%), 23.5% (+/-4.5%), and 11.7% (+/-4.9%) among the index, middle, ring, and small finger, respectively. As the wrist was moved farther away from this position, the forces produced by individual fingers decreased incrementally; however, the decreases in individual finger forces were not proportional, leading to a dependence of finger force-sharing patterns on wrist position.

How do therapists administer the rapid exchange grip test? A survey

The rapid exchange grip (REG) test is one of many methods devised to detect insincere grip strength efforts. Studies investigating the REG test have used different testing protocols and different interpretation criteria for what constitutes a sincere effort. Since therapists get information about evaluation tools from the literature, inconsistencies among researchers may lead to a lack of standardization in the administration of the REG test among therapists. The purpose of the study was to survey therapists to determine what protocol they follow during REG test administration and how they interpret the REG test results. Fourteen therapists working in hand clinics completed the survey. The ways in which the therapists administered the REG test varied widely. Differences among therapists in administering the REG test included the position of the patient, the handling of the dynamometer, the number of repetitions, the hand switch rate, and the comparative test used to interpret the REG test. On the basis of these results, we concluded that the REG test does not meet the most basic testing and measurement criteria. This may impede the ability of therapists to report the outcomes of the REG test accurately and correctly. The implications for the profession due to the lack of standardization of the REG test are discussed.

Elbow positioning for maximum grip performance

Numerous studies have shown that elbow positioning influences grip measurements. These studies have had various and contradictory results. The intent of this study was to clarify the discrepancies and determine which elbow position yields maximal grip strength. Sixty-four men and 64 women were tested on a Greenleaf Medical EVAL system, once with the elbow in full extension and once with the elbow in 90 degrees of flexion. With larger subject groups and computerized data collection, results indicate that-for both the dominant and nondominant hands and regardless of the gender of the subject-grip strength is significantly greater when measured with the elbow in the fully extended position.

Grip strength and the risk of developing radiographic hand osteoarthritis: results from the Framingham Study

OBJECTIVE

In knees, quadriceps strength may protect against osteoarthritis (OA). Muscle activity is a major determinant of forces at the hand joints, and grip is a common task during which high muscle forces are sustained, especially at the proximal hand joints (metacarpophalangeal [MCP] joints and thumb base). This longitudinal study of radiographic hand OA examined the association between incident OA at different hand joints and maximal grip strength.

METHODS

Four hand joint groups were studied: distal interphalangeal (DIP), proximal interphalangeal (PIP), MCP, and the base of the thumb (carpometacarpal and scaphotrapezial combined). Subjects were members of the Framingham OA Study who had a baseline radiograph in 1967-1969 and a followup radiograph in 1992-1993 (mean followup 24 years) and had no prevalent radiographic OA in any hand joint at baseline. Incident disease was defined as development of OA defined as a modified Kellgren/Lawrence grade of > or =2. Grip strength was measured in kilograms by dynamometer in 1958-1961 and again in 1960-1963, and the 2 measures were averaged and divided into sex-specific tertiles. Joint-based analysis was performed by adjusting for age, physical activity, and occupational category using the lowest grip strength tertile as the referent.

RESULTS

Baseline and followup radiographs were obtained from 746 subjects. Of these, 453 subjects with no prevalent OA at baseline were eligible for analysis. In men, higher maximal grip strength was associated with an increased risk of OA in the PIP (highest tertile odds ratio [OR] 2.8 compared with lowest tertile, 95% confidence interval [95% CI] 1.2-6.7), MCP (highest tertile OR 2.9, 95% CI 1.1-7.4), and thumb base joints (highest tertile OR 2.8, 95% CI 1.1-7.4). In women, there was increased risk of OA in the MCP joints (highest tertile OR 2.7, 95% CI 1.1-6.4).

CONCLUSION

Men with high maximal grip strength are at increased risk for the development of OA in the PIP, MCP, and thumb base joints, and women, in the MCP joints. No association was found between maximal grip strength and incident OA in the DIP joints of men or women.