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At least 685 records · Page 38Linked to original sources
PubMed2002

Test-retest strength reliability: hand-held dynamometry in community-dwelling elderly fallers.

OBJECTIVE: To determine the reliability of a standardized protocol by using a hand-held dynamometer (HHD) to measure lower-extremity strength in community-dwelling elderly fallers. DESIGN: Within-session test-retest reliability of the HHD. SETTING: Balance laboratory of a university. PARTICIPANTS: A convenience sample of 41 community-dwelling elders (61-90y) who fell at least once in the previous year. INTERVENTION: The strengths of 8 lower-extremity muscle groups bilaterally were tested twice, with an intervening rest period of 15 seconds. MAIN OUTCOME MEASURE: Maximal isometric force. RESULTS: Test-retest intraclass correlation coefficients (ICCs) were high, generally ranging from.95 to.99 for 1 trial (ICC(2,1)) and from.97 to 1.00 for the mean of 2 trials (ICC(2,2)). There were no significant differences in strength values across trials (P>.05). Men had significantly greater strength than women across all muscle groups (P>.05). Right knee extensor strength demonstrated the largest trial-to-trial difference,.54 kg using a single measurement and.39 kg using the mean of both measurements. Among the 3 lower-extremity muscle groups, the ankle showed higher a coefficient of variation (CV=5.1%-7.4%) than the knee (CV=4.6%-5.1%) or the hip (CV=4.2%-6.3%) when using 1 measure. CONCLUSION: By using an HHD and a standardized measurement protocol, a novice tester can obtain reliable lower-extremity strength values in community-dwelling elderly fallers.

Accidental Falls↗
PubMedDate not supplied

Effects of muscle-strength training on the functional status of patients with osteoarthritis of the knee joint.

This study was designed to determine whether an 8-week isokinetic muscle-strength-training program improved the functional health status of patients with osteoarthritis of the knee joint. Twenty volunteers with osteoarthritis of the knee joint were randomly assigned to either an experimental (n=10) or control (n=10) group. The experimental group completed six sets of five maximal contractions three times per week for 8 weeks on a Cybex II dynamometer at 90 degrees per second. Both groups were pre- and posttest for extension and flexion strength of the right and left legs, the 50-foot walk time, range of motion at the knee joint, the Osteoarthritis Screening Index (OASI), and the Arthritis Impact Measurement Scale (AIMS). There was a significant decrease in pain and stiffness, and a significant increase in mobility. There was also a significant decline in arthritis activity in the experimental group as measured by the OASI and AIMS. The experimental group significantly increased in all strength measures, while the control group increased in only right leg flexion and left leg extension across the training period.

Activities of Daily Living↗
PubMed2004

Scapular rotation in swimmers with and without impingement syndrome: practice effects.

PURPOSE: The purpose of this study was to examine the effects of a normal swim practice on the scapular kinematics of swimmers with impingement syndrome and healthy swimmers. METHODS: Twenty swimmers with no known shoulder pathology and 20 swimmers with shoulder impingement syndrome participated in this study. Shoulder strength measurements were made with a hand-held dynamometer. Static scapular upward rotation was measured with an inclinometer with the arm at rest, and at 45, 90, and 135 degrees of humeral elevation. Measurements were made pre- and postswim training. RESULTS: There were no differences in baseline measurements of kinematics between the two groups. After swimming, both groups experienced muscle fatigue as indicated by a significant reduction in force generation. Although swimming practice resulted in no significant differences in scapular kinematics for the healthy swimmers, there were significant decreases in scapular upward rotation in subjects with shoulder impingement. CONCLUSIONS: Abnormal scapular kinematics in swimmers with impingement syndrome may only be observed after an intense swim practice. The examination of swimmers immediately after swimming may provide more information regarding impingement syndrome than a typical clinical exam.

Adolescent↗
PubMed2004

Tissue adhesives for a sutureless fadenoperation: an experimental study in a rabbit model.

PURPOSE: To use tissue adhesives for a sutureless Fadenoperation to eliminate perioperative risks related to the sutures. METHODS: In an in vivo procedure, 120 superior recti muscles in New Zealand White rabbits were subjected to the posterior fixation procedure, at a distance of 6 mm from the insertion point of the muscle. They were divided into four groups of 30 muscles, according to the material used to perform a myopexy: group 1 (control): nonabsorbable 5-0 polyester sutures; group 2: n-butyl-2-cyanoacrylate adhesive; group 3: fibrin glue; group 4: gelatin-resorcin-formaldehyde-glutaraldehyde (GRFG) adhesive. The animals were examined at 1, 7, 14, and 21 days after surgery. Afterward, they were killed, and their eyes were enucleated to measure the distance between the myopexy and the anatomic insertion point and to assure the strength of the bond with a dynamometer. Finally, a histologic examination was performed. RESULTS: Almost all eyes were clear after the third week, although group 4 presented the most intense inflammatory reaction. In histologic examination, groups 1 and 2 showed a chronic inflammatory reaction of the foreign-body type, with similar intensity. Fibrin glue induced minimal inflammation, but GRFG adhesive produced a pronounced reaction. Concerning the distance of the myopexy, groups 1 and 2 presented measures close to the expected distance of 6 mm, whereas groups 3 and 4 showed a greater variability. All groups performed well in the strength test, with no statistically significant differences among them. CONCLUSIONS: n-Butyl-2-cyanoacrylate adhesive performed best in the sutureless Fadenoperation, characterized by precision in the expected distance of myopexy, sufficient resistance to separation, and acceptable inflammatory reaction.

Animals↗
PubMed2000

Bone mineral density and muscle strength in female ice hockey players.

The purpose of this study was to investigate bone mineral density (BMD) at different sites in female ice hockey players as well as to study the relationship between BMD, muscle strength, and body composition parameters. The study group consisted of 14 female ice hockey players (age 22.2 +/- 4.3 years) which was compared with 14 inactive females (age 21.5 +/- 3.8 years). The two groups were matched for age and weight. Areal bone mineral density was measured in total body, head, lumbar spine, femoral neck, Ward's triangle and the trochanter, using dual energy X-ray absorptiometry. Body composition parameters were derived from the total body scan. Isokinetic concentric peak torque of the left quadriceps and hamstrings muscles was measured using an isokinetic dynamometer. Compared to the inactive group, the ice hockey players had significantly higher BMD of all of the bone sites measured, except for the head, (total body 6.9%, head -2.6%, lumbar spine 8.9%, femoral neck 17.6%, Ward's triangle 20.4%, and trochanter 21.7%). The hockey players also had significantly higher peak torque in the quadriceps and hamstrings muscles. In the ice hockey group, a significant positive correlation was found between BMD of the femoral neck and hamstrings peak torque at 225 degreesisecond (r = 0.67, P < 0.01). In the inactive group, significant positive correlations were found between BMD and peak torque in the hamstrings muscles (90 degrees/second: r = 0.6-0.8, P<0.05 (total body, trochanter) and P<0.01 (spine, neck), 225 degrees/second: r = 0.5-0.8, P<0.05 (total body, Ward's triangle, trochanter) and P< 0,01 (spine, neck)). In the inactive group significant positive correlations was also found between lean body mass and BMD of the trochanter (r = 0.58, P < 0.05). In young females it appears that training and playing ice hockey might influence BMD and muscle strength in a positive direction. The correlation between BMD and muscle strength seems to weaken with increased exercise level.

Absorptiometry, Photon↗
PubMed1994

Grip strength and bone mineral density in older women.

Most previous literature on muscle strength and bone density examined the association between specific muscle groups and adjacent bones. This study examined the association of grip strength with bone density at distant sites, such as the spine and hip, as well as at the wrist and radius. Subjects were 649 postmenopausal women aged 65 years and older. Bone mineral density was measured at the ultradistal wrist and midshaft radius in the nondominant arm using single-photon absorptiometry and at the lumbar spine and hip using dual-energy x-ray absorptiometry. Grip strength was measured in both the dominant and nondominant hands using a dynamometer. Overweight women had significantly stronger grip strength in both hands (p < 0.01 for dominant hand, p < 0.05 for nondominant hand grip strengths). Exercises had significantly stronger grip strength in the nondominant hand than nonexercisers (p < 0.05). Women reporting arthritis had significantly weaker grip strength in both hands than women not reporting arthritis (p < 0.001). There were no significant differences in grip strength by estrogen use, cigarette smoking, or thiazide use. Regression analyses adjusted for age, obesity, exercise, cigarette smoking, thiazide use, arthritis, years postmenopausal, and estrogen use indicated significant positive associations between grip strength and bone density at all sites. Regression analyses stratified by exercise indicated that only women who exercised had significant associations of grip strength with bone mineral density (all p < 0.05). In this cohort of older women, grip strength was an independent indicator of general bone density.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗
PubMed1994

The relationships among knee extensor torques produced during maximal voluntary contractions under various test conditions.

BACKGROUND AND PURPOSE: The purpose of this study was to describe the relationships among measurements of torque produced during selected maximal voluntary contractions of the quadriceps femoris muscles. SUBJECTS: Twenty nondisabled women, ranging in age from 21 to 33 years (X = 25, SD = 3.5), volunteered to participate in the study. METHODS: The subjects were tested on a dynamometer. Subjects performed isometric contractions at 40 and 60 degrees of knee flexion and concentric and eccentric isokinetic contractions at velocities of 30 degrees, 90 degrees, 120 degrees, and 180 degrees/s. Isometric knee extensor torques, concentric knee extensor peak torques, and eccentric knee extensor peak torques were determined for each subject. Coefficients of determination (r2) and linear regression equations were calculated to determine the strength and nature of the relationships among the measurements. RESULTS: The coefficients of determination ranged from .60 to .94. CONCLUSION AND DISCUSSION: The torque measurements were moderately to highly correlated, suggesting that the measurements obtained during different maximal voluntary contractions may be assessing similar components of performance.

Adult↗
PubMedDate not supplied

Alterations in grip strength during male sexual arousal.

Although it is known that alterations in grip strength occur under a number of conditions, little is known about relationships between grip strength and sexual arousal. This relationship was investigated in 30 healthy heterosexual males, who viewed both erotic and nonerotic videos. A questionnaire was used to assess the extent of sexual arousal. The grip strengths of both hands were measured with a five-position (P1-P5) dynamometer, before and after watching the videos. After watching the erotic video, there was a statistically significant reduction in grip strength for the P2 position, with nonsignificant overall reductions in grip strength for all other positions tested. No such effect was observed in control tests. The results indicate that during sexual arousal, the neural system is likely to reduce the output to muscles not directly related to sexual function, presumably to enhance the physiological responses of sexual arousal.

Adult↗
PubMed2003

Reliability of stabilised commercial dynamometers for measuring hip abduction strength: a pilot study.

BACKGROUND: Reliable quantification of hip abductor strength in a clinical setting is challenging. OBJECTIVES: To examine the intrarater and interrater reliability of three commonly used commercial dynamometers in the measurement of hip abduction. METHODS: Supine gravity minimised measures of unilateral hip abduction strength were recorded in 10 women (mean (SD) age 23.5 (1.9) years) using three different commercially available dynameters. Measurements were repeated over a three day period with a different device used on each day. RESULTS: Intrarater reliability ranged from 0.880 to 0.958 across the three devices, and measures of interrater reliability ranged from 0.899 to 0.948. CONCLUSION: Commercially available dynamometers can be used to quantify hip abduction strength with good to excellent reliability. A previously undescribed method of quantifying hip abduction strength in a clinical setting using readily available instrumentation is presented.

Adult↗
PubMed1997

Invertor vs. evertor peak torque and power deficiencies associated with lateral ankle ligament injury.

Strengthening of the evertor muscles is widely advocated as a key component of lateral ankle sprain rehabilitation, but our clinical observation of impaired invertor muscle performance among many patients suggested the need for this study of isokinetic performance deficiencies. Subjects were 30 physically active adolescents, ages 14-19 years, who had recently sustained a lateral ankle sprain or who had symptoms of chronic lateral ankle instability. Eversion/inversion testing was performed on a Biodex isokinetic dynamometer at speeds of 30 and 120 degrees/sec. Analysis of variance results demonstrated significantly greater (p < .05) invertor deficits than evertor deficits for both peak torque and average power at both tests speeds. The findings of this study suggest that a lateral ankle ligament injury may be associated with an invertor muscle performance deficiency, and that restoration of a normal evertor/invertor strength relationship may be accomplished through performance of an isotonic ankle strengthening program.

Adolescent↗
PubMed2006

Reliability of normalisation methods for EMG analysis of neck muscles.

Acceptable reliability of normalisation contractions in electromyography (EMG) is paramount for testing conducted over a number of days or if normal laboratory strength testing equipment is unavailable. This study examined the reliability of maximal voluntary isometric contractions (MVIC) and sub-maximal (60%) isometric contractions for use in neck muscle EMG studies. Surface EMG was recorded bilaterally from eight sites around the neck at C4/5 level from five healthy male subjects. Subjects performed MVIC and sub-maximal normalisation contractions using an isokinetic dynamometer (ID) and a portable cable dynamometer with attached strain gauge (PCD) in addition to a MVIC against a manual resistance (MR). Subjects were tested in flexion, extension, left and right lateral bending and were retested by the same tester within a two-week period. Intra class correlation co-efficients (ICC) were calculated for each testing method and contraction direction and a mean ICC was calculated across all contraction directions. All normalisation methods produced excellent within-day reliability (mean ICC >0.80) but only the MVICs using the ID and PCD had acceptable reliability when assessed between-days. This study confirmed the validity of using MVICs elicited using the ID and PCD as reliable reference contractions for the normalisation of neck EMG.

Adult↗
PubMed2006

A new versatile hand dynamometer.

This paper describes the design and testing of a new hand strain-gauge based dynamometer. The design is portable and capable of measuring grip strengths from 12.5 to 800N. The dynamometer is independent of point of application of the grip force. Finite element modelling and experimental testing were used to verify the mechanical system's suitability. The dynamometer was designed for input to a PDA to allow full portability of the device.

Biomechanical Phenomena↗
PubMed2001

Nutrition and handgrip strength of older adults in rural Malawi.

OBJECTIVE: To examine the relationship between the nutritional status and handgrip strength of older people in rural Malawi. DESIGN: Cross-sectional study. SETTING: : Lilongwe rural, Malawi, situated approximately 35-50 km from the city. SUBJECTS: Ninety seven males and 199 females participated in this study. METHODS: Selected anthropometric measurements were taken and nutrition indices were computed using standard equations. Handgrip strength was measured using an electronic grip strength dynamometer. RESULTS: The mean handgrip strength (in kg) for men was significantly higher than for women vs. In addition, there was a significant decline in handgrip strength with age in both sexes. Furthermore, handgrip strength was positively correlated to the following nutritional status indicators: BMI in males and in females), mid-upper arm circumference (MUAC) in males and in females) and arm-muscle area (AMA) in males and in females). After controlling for potential confounders, namely sex, height and age, the correlations between handgrip strength and the nutrition indices were still significant. CONCLUSION: The results of this study support the hypothesis that poor nutritional status is associated with poor handgrip strength. Malawian males had both lower handgrip strength and lower arm muscle area than their counterparts from industrialised countries. However, Malawian females had similar handgrip strength despite lower arm muscle area, in comparison with women from industrialised countries, reflecting perhaps their higher level of physical activity. Further studies are required to determine whether by alleviating nutritional problems a concomitant improvement in handgrip strength can be obtained.

Aged↗
PubMedDate not supplied

Motor skill learning of concentric and eccentric isokinetic movements in older adults.

Neuromuscular adaptation at the onset of resisted exercise can be observed as increases in torque and surface electromyography. The effect of learning the motor task has been hypothesized to contribute to these early increases, especially for older people. Thus, the purpose of this study was to investigate the facilitatory effects of practice on motor performance in older adults during short-term isokinetic training of the ankle dorsiflexors (DF). Twenty-eight men and women (M = 76.3 +/- 4.6 years) volunteered for a 2-week, 3-days/week strength training program. They were tested in a sitting position on a KinCom isokinetic dynamometer at 30, 90, and 180 degrees s-1 through 40 degrees of DF movement (concentric and eccentric contractions). Criterion curves of lever arm angle patterns were cross-correlated with subject-generated angle patterns, showing significantly better correlations on posttest versus baseline. Smoothness and proficiency of muscle contraction improved with practice by fewer hesitations in movement and increased ability to change between concentric and eccentric muscle contractions. Increased agonist electromyography and torque were hypothesized to be secondary to greater neural drive and/or synchronization of motor unit firing rate and/or recruitment during maximal voluntary contraction, improved coordination, and adapted neural control of concentric and eccentric muscle contraction.

Aged↗
PubMed1985

Skeletal muscle function in man: force, relaxation rate, endurance and contraction time-dependence on sex and age.

Two different methods for estimating muscle function were compared; hand grip strength (HGS) and adductor pollicis muscle function after electrical stimulation of the ulnar nerve. Fifty-two 'normal' subjects, who were divided into four groups, according to sex and age, were investigated. Technical modifications of the latter method are presented for the measurement of human skeletal muscle function, independent of the motivation of the subject. Maximal voluntary force, as measured with a hand dynamometer, was higher in males than in females. Young males were stronger than males over 50 years old, and young females were stronger than old women. The statistical analysis of the muscle function variables after electrical stimulation showed that young females developed relatively more force at low stimulating frequencies than females over 50 years old. Females had a significantly longer contraction time to tetany compared to males. The relaxation rate after tetanic stimulation was independent of sex and age. Endurance was reduced in old males compared to females in the same age-group and to young males.

Adult↗
PubMed2000

Depressed mood and body mass index as predictors of muscle strength decline in old men.

OBJECTIVE: To study depressed mood as a predictor of strength decline within body weight categories over a 3-year follow-up period. DESIGN: A prospective cohort study over 3 years. SETTING: Honolulu, Hawaii. PARTICIPANTS: The subjects were 2275 men participating in the Honolulu Heart Program with an average age of 77.1 years (range 71-92 years), who were not cognitively impaired at baseline (Exam 4), and who participated in maximal hand grip strength measurements at baseline and 3 years later (Exam 5). MEASUREMENTS: Hand grip strength was measured using a dynamometer. Depressive symptoms were studied using an 11-item version of Center for Epidemiologic Studies Depression Scale with 9 as a cutoff. Body weight categories were formed on the basis of body mass index (BMI) (BMI = weight/height2; underweight: BMI < 20; normal weight: BMI 20-24.99, overweight: BMI > or = 25). MAIN RESULTS: At baseline, 9.4% of the participants were rated as having depressed mood. The mean individual strength change over 3 years was - 6.9% (standard deviation 14.0). Steep strength decline was determined as losing > or = 14% (lowest quartile). The proportions of those with steep strength decline in the groups based on combined distributions of BMI and depressed mood were: underweight/ depressed (n = 22) 41%, underweight/not depressed (n = 200) 28%, normal weight/depressed (n = 127) 30%, normal weight/not depressed (n = 1181) 25%, overweight/depressed (n = 55) 31%, overweight/not depressed (n = 675, referent) 21%. After adjusting for baseline strength, age, height, sociodemographic variables and diseases, the odds ratio for steep strength decline was more than four times greater among those who were depressed and underweight, and twice as great among people who were depressed and normal weight compared with those who were nondepressed and overweight. The risks of nondepressed under- and normal weight people and depressed overweight people did not differ from the reference group. CONCLUSIONS: Depressed mood was associated with increased risk of steep strength decline, in particular in older men with low body weight. Low body weight in combination with depressed mood may be an indicator of frailty or severe disease status that leads to accelerated strength loss and disability.

Aged↗
PubMedDate not supplied

Intraobserver and interobserver reliability for the strength test in the Constant-Murley shoulder assessment.

This study evaluates the standardized strength test in the Constant-Murley shoulder assessment of adults with healthy shoulders in a randomized, single-blind design. The following questions were to be answered: (1) Can the spring balance and a digital dynamometer both yield the same result? (2) What is the intraobserver and interobserver reliability of the strength test? (3) Is the strength test sensitive to change in technique or affected by calculation with mean or maximum values? Ten subjects were included in a comparison of the Handyscale (digital dynamometer) and the mechanical spring balance for concurrent validity, resulting in intraclass correlation coefficient values ranging from 0.96 to 0.99. For intraobserver and interobserver reliability, 2 observers tested 20 subjects with the Handyscale and retested them after 2 weeks. Regardless of technique during testing, this resulted in almost perfect agreement (intraclass correlation coefficient range, 0.89-0.98). The digital dynamometer can replace the conventional spring balance. The standardized strength test in the Constant-Murley shoulder assessment is reliable in young subjects with healthy shoulders, independent of technique or whether calculated with mean or maximum values.

Adult↗
PubMed1989

Measurement of strength and loading variables on the knee during Alpine skiing.

The study focusses on the prevention of knee injuries during snow skiing. In order to develop a technology of knee injury prevention, both the strength and loading on the knee during skiing activity must be known. This paper reports measurements of variables influencing both knee strength and loading of the joint. The strength variables measured included the degree of activity in six muscles crossing the knee, the knee flexion angle, and the axial load (i.e. weight bearing) transmitted to the knee. Transducers included surface electrodes to monitor electromyogram signals indicating the degree of muscle activity and a goniometer to measure both hip and knee flexion angles. The complete loading on the knee was derived from a dynamometer which measured the six load components at the boot-dynamometer interface. The transducer data were acquired and stored by a compact, battery powered digital data acquisition-controller system. Three male subjects of similar physical size (nominal was 1.8 m and 75 kg) and skiing ability (advanced intermediate to expert) were tested under similar conditions. Each subject skied a total of four slalom runs--one snowplow and three parallel. The total time of each test was 21 s. Example data plots from different types of runs are presented and discussed. Based on observations from the data, necessary performance features for ski bindings offering improved protection from knee ligamentous injuries are defined.

Adult↗