PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Muscle Strength”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 811 records · Page 45Linked to original sources
PubMed1983

The measurement of muscle strength in patients with peripheral neuromuscular disorders.

The variability of voluntary isometric strength measurements has been assessed in normal subjects and patients with peripheral neuromuscular disorders. Knee extensor strength was measured in a muscle testing chair 13 times over 5 months in each of six normal subjects: coefficients of variation (CV) ranged from 4.5 to 14.0% (mean 8.5%) for individual legs in different subjects. Paired measurements of the strength of several clinically weak muscle groups were made 1-4 days apart in 20 patients using both a handheld dynamometer and the muscle chair technique: the test/retest correlation was high (r = 0.97, p less than 0.001). Visual biofeedback did not affect the strength recorded in most cases. Each of five patients had the strength of six or seven clinically weak muscle groups measured by five examiners within a 24 hour period: the CV for the five examiners ranged from 3.6-27.3% (mean 12.8%). A single examiner measuring the same groups on five occasions in three patients obtained a mean CV of 8.9%. Sources of variation are analysed and it is concluded that, with certain precautions, voluntary strength measurements offer a simple, reliable and acceptable method for monitoring change in patients.

Adolescent↗
PubMed2003

Leg muscle strength is reduced in Parkinson's disease and relates to the ability to rise from a chair.

Individuals with Parkinson's disease (PD) have difficulties rising from a chair; however, factors contributing to this inability have never been investigated. We compared lower extremity strength between individuals with PD and healthy controls and quantified the relationships between strength and the ability to rise from a chair. Ten men with mild PD and 10 sex- and age-matched controls performed maximal concentric, isokinetic knee and hip extensor torque on an isokinetic dynamometer to quantify muscle strength. Subjects also rose from a chair at their comfortable pace without the use of their arms and the duration of this task provided a measure of sit-to-stand (STS) ability. Subjects with PD were tested in an on- and off-medication state on different days. Mean hip and knee extensor torques were lower in subjects with PD, with greater deficits found at the hip. Greater hip strength was related to better STS ability in subjects with PD while greater knee strength was related to better STS ability in controls. These results show that individuals with mild PD generate smaller extremity forces compared to controls. Reduced strength, particularly at the hip, may be one factor that contributes to the difficulty of persons with PD to rise from a chair.

Antiparkinson Agents↗
PubMed1991

Correlation of phasic muscle strength and corticomotoneuron conduction time in multiple sclerosis.

Central motor conduction times for the adductor pollicis muscle, the twitch force of that muscle to scalp magnetic motor cortex stimulation, and the maximum force of phasic voluntary contraction of the same muscle were measured in 15 patients with multiple sclerosis. Two tests of manual dexterity of the same hand also were studied: the Purdue pegboard test, and the maximal frequency of a scissors movement of the thumb and index finger. The patients had normal strength or minimal weakness of the intrinsic muscles of the hand on clinical examination. The mean central motor conduction times for the adductor pollicis muscle for the patients were longer than normal, the peak twitch force of the adductor pollicis muscle evoked by cortical stimulation and the maximum force of a phasic voluntary contraction of the adductor pollicis muscle were smaller than normal. There were strong correlations between all these measures. Central motor conduction time in the patients was inversely correlated with voluntary phasic force and the twitch force after cortical stimulation. That is, the longer the central motor conduction time, the weaker the force. Prolonged central motor conduction time is likely to be accompanied by conduction block in corticomotoneuron pathways. The correlation of central motor conduction time with voluntary phasic force and the twitch force most likely reflects the degree of conduction block and temporal dispersion rather than delay in conduction per se. These results indicate that objective assessments of phasic muscle strength may reveal correlations with central motor conduction time that are not evident on conventional clinical examination which assesses tonic muscle contraction strength.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2003

Modified exercise test in screening for mitochondrial myopathies--adjustment of workload in relation to muscle strength.

The aim of this study was to evaluate the usefulness of a modification of the bicycle ergometer test, the subanaerobic threshold exercise test (SATET), as a screening test for patients with mitochondrial myopathies. Since the original SATET is frequently found to be strenuous for weak patients, a new variable (relative muscle strength) was added to the workload formula. Plasma lactate levels were recorded at rest, then after 5 and 15 min of cycling on an ergometer, with constant workload. Nine patients with mitochondrial myopathy, 10 patients with other neuromuscular diseases and 9 healthy but sedentary volunteers undertook the test. An upper reference limit after exercise for plasma lactate was settled at 2.9 mmol/l. The modified SATET showed a sensitivity of 78% and a specificity compared to the healthy subjects of 100%. Compared to patients with other neuromuscular diseases, the specificity was lower (60%). All subjects completed the test without severe fatigue or pain.

Adult↗
PubMed2004

Inspiratory muscle strength training with behavioral therapy in a case of a rower with presumed exercise-induced paradoxical vocal-fold dysfunction.

Paradoxical vocal fold dysfunction (PVFD) with high effort exercise can result in disruptions to ventilation, dyspnea, inspiratory stridor, elevated heart rate, and syncope. This single subject study experimentally tested an inspiratory muscle strength training (IMST) program with behavioral therapy on a 15-year-old male crew member. Outcome variables were maximum inspiratory pressure (MIP), and dyspnea ratings. Following 5 weeks of IMST, MIP increased by 93% from baseline function while dyspnea ratings substantially decreased. Outcome included successful competition with his high-school crew team, a task he was previously unable to complete. Discussion focuses on IMST combined with traditional approaches of voice therapy for treating PVFD.

Adolescent↗
PubMed1997

Body composition and muscle strength in women scheduled for a knee or hip replacement. A comparative study of two groups of osteoarthritic women.

It is unclear whether patients with knee osteoarthritis (OA) and hip OA differ regarding soft tissue composition and bone mineral density (BMD). A total of 42 women waiting for a replacement of the hip (n = 20) or the knee (n = 22) due to OA were examined. Fat mass (FM), percent body fat (%fat), lean mass (LM) and BMD were measured by dual energy X-ray absorptiometry (DEXA). Knee extensor and flexor strength was measured by an isokinetic dynamometer. No significant differences in age, height, disease duration, Lequesne score or pain scores were found between the groups. Comparing the radiographic changes of the knees with those of the hips, changes were most severe in the joints which were to be replaced. Body weight, body mass index, total and regional FM, and %fat were more than 15% higher in patients waiting for a knee replacement (p < 0.001). Also lean mass tended to be higher in the knee patients. Differences in BMD did not remain statistically significant after correction for body weight. Muscle strength was similar in the two groups but was reduced by 20% in the legs in which the joint was to be replaced compared to the contralateral legs. However, the mean difference in lean mass between the two legs was only 3% (p < 0.05). The scores for pain felt during strength testing were significantly higher for the involved legs than for the contralateral legs. In conclusion, fat mass values were considerably higher in patients scheduled for a knee replacement. Impaired strength performance in OA may be more strongly associated with pain than with reduced muscle mass.

Aged↗
PubMed1986

Grip strength, muscle fatigue, and body composition in nomadic Turkana pastoralists.

Tests of hand grip strength and hand grip muscle fatigue were conducted on Ngisonyoka Turkana pastoralists of northwest Kenya to explore some of the functional relationships between activity and body composition. The test of maximal voluntary contraction (MVC) of hand grip flexors was conducted on 151 Turkana and 38 U.S. men and women. The fatigue test was conducted on the same number of subjects who were instructed to attempt to maintain 80% of the MVC for 90 seconds. The results of these tests, combined with arm measurements of size and body composition, were used to evaluate muscle size and strength relationships and to estimate muscle fiber type distribution in the forearm. MVC values of Turkana men were low by U.S. and European standards. The low values resulted from smaller Turkana muscle areas. MVC values of Turkana women were comparable to those of U.S. and European women, reflecting comparable muscle areas. The fatigue curves of Turkana and U.S. men and women suggest that slow-twitch aerobic muscle fibers predominate for the hand grip flexors of the Turkana pastoralists.

Adult↗
PubMed1998

Improvement of physical fitness and muscle strength in polymyositis/dermatomyositis patients by a training programme.

In the present investigation, the benefit of physical training in patients with inflammatory myopathy was studied. In this prospective, randomized, controlled study, 14 patients with polymyositis (PM) or dermatomyositis (DM) were investigated. The training, consisting of bicycle exercise and step aerobics, took place over a 6 week period. Baseline and endpoint measurements included an 'activities of daily living' (ADL) score, peak isometric torque (PIT) generated by muscle groups in the lower extremities, peak oxygen consumption (VO2max), and creatine phosphokinase (CPK) levels. There was no significant rise in disease activity in the training group in comparison to the controls. The ADL score for the treatment group, in comparison to the control group, improved (P < 0.02), PIT rose (P < 0.05) and there was a statistically significant increase in oxygen uptake relative to body weight (P < 0.05). No rise in inflammatory activity, but significant improvement in muscle strength, oxygen uptake and well-being, were found in patients with inflammatory myopathy as a result of physical training. Besides medication, a physical training programme consisting mainly of concentric muscle contractions should therefore be an integral part of therapy, particularly in view of the cardiopulmonary risk of these patients.

Adult↗
PubMed2005

Jump-land characteristics and muscle strength development in young athletes: a gender comparison of 1140 athletes 9 to 17 years of age.

BACKGROUND: Many authors have speculated that altered neuromuscular control and strength of the lower extremity are responsible for the gender disparity in knee ligament injury rates. HYPOTHESIS: Significant increases in normalized quadriceps and hamstrings strength and limb symmetry on single-legged hop test occur with age. No gender differences in strength occur until age 14 years, after which boys generate greater peak torques than do girls. Age and gender do not influence lower limb alignment on a drop-jump test. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: We studied the effects of age and gender in 1140 athletes, 9 to 17 years old, on muscle strength and neuromuscular control during functional activities. Isokinetic quadriceps and hamstrings strength was measured at 300 deg/s. Limb symmetry was assessed with single-legged hop tests. A video drop-jump test determined lower limb alignment in the coronal plane. RESULTS: Extension peak torques significantly increased with age; maximum strength was noted in girls at age 13 years and in boys at age 14 years (P < .001). Although maximum flexion strength occurred in boys at age 14 years (P < .001), girls had only slight increases from ages 9 to 11 years (P = not significant). Boys aged 14 to 17 years had significantly greater normalized isokinetic strength than did age-matched girls. No age or gender effects existed in limb alignment on the drop-jump test or limb symmetry on single-legged hop testing. CONCLUSION: Maximum hamstrings strength was noted in female athletes by age 11 years, compared with age 14 years in male athletes, and a distinct lower limb valgus alignment existed in the majority of all athletes on landing. The absence of a gender difference in lower limb alignment on landing suggests other factors may be responsible for the gender disparity in knee ligament injury rates.

Adolescent↗
PubMed1988

Muscle strength in the triceps surae and objectively measured customary walking activity in men and women over 65 years of age.

1. Objective measurements of the maximal voluntary strength of triceps surae and the amount and speed of customary walking have been made in 56 men and 66 women aged over 65 years, who were living independently. 2. Strength was measured using a dynamometer based upon a hydraulic system (Bourdon tube). Walking was assessed, for amount using a mechanical accelerometer (pedometer) over a week, and for speed using a self-paced test for normal walking over 100 m on the level. The reliability and validity of these methods has been described. 3. The men were significantly stronger (1128 +/- 206 vs 873 +/- 177 N) even after adjustment for body weight; their amount of walking was similar to that of women, but they walked significantly faster (4.8 +/- 0.6 vs 4.2 +/- 0.6 km/h). Men were significantly more active in leisure pursuits (as assessed by questionnaire). 4. Significant associations between strength and chosen normal walking speed were found for both sexes (r = 0.41, P less than 0.001 for men and r = 0.36, P less than 0.01 for women). The amount of walking (daily stepscore as a mean from 7 consecutive days recorded) was significantly but less strongly correlated with strength (r = 0.30, P less than 0.05) in the men only. 5. Multiple regression analysis showed that in men neither age nor amount of walking had any further effect in addition to speed, but in women age had an additional effect (multiple R = 0.48). 6. An association has been demonstrated which raises the possibility of reversing loss of muscle strength through increased daily activity.

Aged↗
PubMedDate not supplied

The effect of low-intensity aerobic exercise on muscle strength, flexibility, and balance among sedentary elderly persons.

An experimental group of 20 elderly subjects participated in 8 weeks of low-intensity aerobic exercise while 27 subjects in a comparison group maintained their usual level of activity. The program consisted of stretching and strengthening chair exercises. A significant difference between the groups was found for flexibility of the ankles and the right knee. No significant difference was found between the groups for muscle strength or balance, although the experimental group improved their balance by 22%.

Accidental Falls↗
PubMed2000

Riluzole prolongs survival and delays muscle strength deterioration in mice with progressive motor neuronopathy (pmn).

The neuroprotective drug riluzole (Rilutek) is a sodium channel blocker and anti-excitotoxic drug which is marketed for the treatment of amyotrophic lateral sclerosis (ALS). Previous studies have shown that riluzole prolongs survival of transgenic mice harboring the mutated form of Cu,Zn-superoxide dismutase found in familial forms of the human disease. In this study we have examined the effect of treatment with riluzole in mice suffering from progressive motor neuronopathy (pmn), a hereditary autosomal recessive wasting disease which shares some symptoms of ALS. These mutants display hind limb weakness starting during the 3rd week of life and leading to paralysis and death during the 7th week of life. Daily treatment with 8 mg/kg of riluzole by oral route significantly retarded the appearance of paralysis, increased life span and improved motor performance on grip test and electromyographic results in the early stage of the disease. There was no effect of riluzole on weight gain. These data demonstrate that riluzole significantly prolongs life span, retards the onset of paralysis and slows the evolution of functional parameters connected with muscle strength in the pmn mouse model of motor neuron disease.

Animals↗
PubMed2003

[Progression of study on the relationship between muscle strength, physical activity and bone mineral density].

Osteoporosis is a skeletal disease characterized by low bone mass and microarchitectural deterioration of bone tissue, with a consequent increase in fragility and susceptibility to fractures resulting in the severe health consequences to human health. Many investigations have been done in exploring the etiological factors so as to find out approaches for prevention and treatment of osteoporosis. Low bone mineral density is one of the important clinical characteristics of osteoporosis. In this paper, the progress of study on the relationship between muscle strength, physical activity and bone mineral density was reviewed.

Animals↗
PubMedDate not supplied

[Changes of lung volumes and respiratory muscle strength in patients with growth hormone deficiency].

The relationship between growth hormone deficiency (GHd) and ventilatory function is not well understood. We studied 7 patients with GHd since childhood who had been adequately treated with replacement therapy until cartilage fusion. Together with 7 well-matched (age and body-type) healthy control subjects, they underwent spirometry including determination of residual volume, and lung diffusing capacity. Also recorded were maximal respiratory muscle pressure during inspiration (PImax) and expiration (PEmax). Patients with GHd showed a significant reduction in total lung capacity and vital capacity while residual volume and lung diffusing capacity remained unchanged. All patients had a significant reduction of both PImax and PEmax. Previously treated adult subjects with GHd present a persistent decrease in lung mobilizing volumes associated with reduced respiratory muscle strength. These alterations may have implications in the management of GHd in adult patients.

Adult↗
PubMed2004

[Effects of sports and media consumption on the trunk muscle strength, posture and flexibility of the spine in 12- to 14- year-old adolescents].

INTRODUCTION: Back pain and posture deficits get more common in childhood and adolescents. Lack of movement, insufficient physical education and high amounts of TV and PC are known as risk factors for chronic low back pain in later life. METHODS: In a cross-sectional study, trunk muscle strength, posture and spinal flexibility were assessed in 200 untrained schoolchildren (117 girls, 83 boys). Independent variables, collected by a standardized questionnaire: age, height, weight, gender, weekly scope of TV, PC and sports (conditional, conditional-coordinative, coordinative). DEPENDENT VARIABLES: spinal parameter, tested by the Zebris CMS-System and IPN Back Check. OUTCOMES: PC and TV-consumption had negative effects on the spinal parameter, whereas esp. conditional-coordinative sports correlated positively. DISCUSSION: For general health and preventive reasons, children need a daily minimum of 30 minutes of movement. Conditional-coordinative sports are suited best because of their multifactorial load.

Abdomen↗