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At least 973 records · Page 54Linked to original sources
PubMed1988

Make tests and break tests of elbow flexor muscle strength.

The purposes of this investigation were 1) to compare the forces produced by the elbow flexor muscles during make tests and break tests and 2) to determine the reliability of each of the test procedures. I used a hand-held dynamometer to perform two make tests and two break tests on 27 young women. The forces produced by the elbow flexor muscles during break tests were significantly larger than (p less than .001), albeit correlated with (r greater than .80), the forces produced during make tests. Each testing procedure was reliable (r = .909 for make tests; r = .922 for break tests). On the basis of reliability, one type of testing cannot be considered clearly superior to the other.

Adult↗
PubMedDate not supplied

Bone adaptation to altered loading after spinal cord injury: a study of bone and muscle strength.

Bone loss from the paralysed limbs after spinal cord injury (SCI) is well documented. Under physiological conditions, bones are adapted to forces which mainly emerge from muscle pull. After spinal cord injury (SCI), muscles can no longer contract voluntarily and are merely activated during spasms. Based on the Ashworth scale, previous research has suggested that these spasms may mitigate bone losses. We therefore wished to assess muscle forces after SCI with a more direct measure and compare it to measures of bone strength. We hypothesized that the bones in SCI patients would be in relation to the loss of muscle forces. Six male patients with SCI 6.4 (SD 4.3) years earlier and 6 age-matched, able-bodied control subjects were investigated. Bone scans from the right knee were obtained by pQCT. The knee extensor muscles were electrically stimulated via the femoral nerve, isometric knee extension torque was measured and patellar tendon force was estimated. Tendon force upon electrical stimulation in the SCI group was 75% lower than in the control subjects (p<0.01). Volumetric bone mineral density of the patella and of the proximal tibia epiphysis were 50% lower in the SCI group than in the control subjects (p<0.01). Cortical area was lower by 43% in the SCI patients at the proximal tibia metaphysis, and by 33% at the distal femur metaphysis. No group differences were found in volumetric cortical density. Close curvilinear relationships were found between stress and volumetric density for the tibia epiphysis (r(2)=0.90) and for the patella (r(2)=0.91). A weaker correlation with the tendon force was found for the cortical area of the proximal tibia metaphysis (r(2)=0.63), and none for the distal femur metaphysis. These data suggest that, under steady state conditions after SCI, epiphyseal bones are well adapted to the muscular forces. For the metaphysis of the long bones, such an adaptation appears to be less evident. The reason for this remains unclear.

Adult↗
PubMed1999

Isokinetic knee muscle strength of individuals with mental retardation, a comparative study.

The purpose of this study was to assess differences in isokinetic muscle torque in the knee among mentally retarded individuals with Down syndrome, mentally retarded individuals without Down syndrome, and sedentary subjects without mental retardation (ns of 7, 8, and 12, respectively). Subjects performed strength tests to knee extension and flexion on a Cybex II isokinetic dynamometer. The measure was peak torque at angular velocities of 60, 120, and 300 degrees/sec. For the Mentally Retarded subjects with and without Down syndrome, the test was performed on two separate days 24 hr. apart. For Sedentary subjects, testing was performed on one day. Their scores indicated significantly higher values of torque than the two other groups. Also, subjects with Down syndrome had inferior muscle torque of lower extremities than peers in the Mentally Retarded Group.

Adult↗
PubMed1975

Work capacity, muscle strength and SDH activity in both legs of hemiparetic patients and patients with Parkinson's disease.

In recent muscle metabolic studies, patients with moderate upper motor neuron lesions showed marked difficulty in performing an equal submaximal work load (bilaterally) in two-legged exercise. For a better evaluation of these patients, studies were performed on each leg separately. Six patients with Parkinson's disease and six with moderate hemiparesis were studied. During one-legged submaximal and maximal exercise heart rate, oxygen uptake, and blood lactate were determined. Maximal voluntary contraction in knee and ankle flexion and extension for each leg was measured. Succinate dehydrogenase (SDH) activity in the thigh muscles was determined. During submaximal exercise, oxygen uptake, heart rate and blood lactate increased more in the paretic leg of hemiparetic patients and in the more affected leg of the Parkinson patients. In hemiparetic patients maximal voluntary contraction of flexors and extensors of the knee was significantly reduced in the paretic leg but was reduced even in the nonparetic knee flexors. SDH activity was very low in both legs in all patients and lowest in the paretic and more affected leg, respectively. It is concluded that (a) the general muscle inactivity per se, secondary to the neurological disorder, may lead to a reduced work capacity; (b) the increased heart rate and blood lactate level seem to be correlated to the relative exercise level of each leg; and (c) in patients with impaired muscle function of one or both legs, evaluation of each leg separately with regard to work capacity and muscle metabolism is of value.

Adult↗
PubMed2003

[Change in muscle strength in patients with anorexia nervosa during inpatient treatment--a pilot study].

OBJECTIVE: Changes in muscular strength during treatment of inpatients suffering from anorexia nervosa were to be documented by exact measurement. METHODS: The maximum strength of each side of the body was measured in 10 patients in the 1st, 2nd, 3rd, 4th, 6th, 8th and 10th weeks of inpatient treatment by means of a series of four different exercises. A well-established measurement technique, including the computer program "Quantitative Muscle Assessment", was used. All patients showed comparable symptoms of an anorexia nervosa, restricting type before admission (pure food restriction without over-exercising). RESULTS: A polyphase course of the restitution of muscular strength could be seen in all patients. Since it is easily applied, the exercise "handigrip" has been used frequently elsewhere. In our study it failed to show a consistent development, in contrast to other muscle groups studied. Differences between the left and right sides could not be observed. CONCLUSIONS: Patients with anorexia nervosa showed an objectively comparable inter-individual polyphase increase in the maximum strength of the muscles under investigation during weight restitution.

Adolescent↗
PubMed2003

A comparison of muscle strength testing techniques in amyotrophic lateral sclerosis.

OBJECTIVE: To assess the reliability of strength testing techniques among centers investigating patients with amyotrophic lateral sclerosis. METHODS: The authors compared test reliability in manual muscle testing (MMT) and maximal voluntary isometric contraction (MVIC) scores among institutions and test validity by comparing change over time between MMT and MVIC. The authors examined 63 subjects at 3-month intervals for 12 months. At enrollment and at 6 months, two physical therapists each examined the subjects twice. MMT scores were calculated as modifications of the Medical Research Council scale. MVIC scores were generated as standardized megascores. Intraclass correlation coefficients and coefficients of variation compared reproducibility, and Pearson correlation coefficients compared change over time. The power of each measure to detect disease progression over time was assessed by estimating coefficients of variation for the average change. RESULTS: Reproducibility between MVIC and MMT was equivalent. Sensitivity to detect progressive weakness and power to detect this change, however, favored MMT, an effect largely accounted for by the number of muscles sampled. CONCLUSIONS: In multicentered trials, uniformly trained physical therapists reproducibly and accurately measure strength by both MMT and MVIC. The authors found MMT to be the preferred measure of global strength because of its better Pearson correlation coefficients, essentially equivalent reproducibility, and more favorable coefficient of variation.

Amyotrophic Lateral Sclerosis↗
PubMed1996

Swelling of the knee joint: effects of exercise on quadriceps muscle strength.

OBJECTIVE: To investigate the effects of excessive fluid in the knee joint on the performance of the quadriceps muscles and to determine whether quadriceps muscle performance can be altered by exercising the swollen joint. DESIGN AND SETTING: A before-after trial design was used, and the procedures were performed in a laboratory setting. SUBJECTS: A random sample of 27 adult men with no musculoskeletal problems was divided into intervention and control groups. INTERVENTION: First, in all groups, torque generated by the quadriceps muscle was examined by isokinetic muscle testing undertaken at a joint angular velocity of 120 degrees/sec over a range of motion from 5 degrees to 80 degrees flexion. After this initial test, in group 1, 60mL saline and dextrose was injected into the knee joint and subjects repeated the maximal effort procedure. Subjects then performed submaximal exercise for 3 to 4 minutes, after which maximal effort testing was undertaken again. In group 2, subjects received no injection of fluid, undertook 2 maximum effort tests, then performed submaximal exercise for 3 to 4 minutes, after which maximum effort testing was undertaken again. In group 3 (control group), subjects undertook three maximum effort tests over a time period similar to that for the other groups. MAIN OUTCOME MEASURE: Quadriceps muscle torque generated at 60 degrees from full knee extension. RESULTS: Torque decreased (p < .05) 30% immediately after the injection of fluid. However, torque returned to preinjection levels after submaximal exercise (p > .05). These findings were related to joint capsule compliance and fluid movement. No significant changes (p > .05) in torque were observed for the other two groups. CONCLUSION: Submaximal exercise of swollen knee joints can decrease artificially induced quadriceps muscle inhibition. These findings may have implications for patients with perennial effusions who at times undertake gait activities.

Adult↗
PubMed2001

A mutation in alpha-tropomyosin(slow) affects muscle strength, maturation and hypertrophy in a mouse model for nemaline myopathy.

Nemaline myopathy is a hereditary disease of skeletal muscle defined by a distinct pathology of electron-dense accumulations within the sarcomeric units called rods, muscle weakness and, in most cases, a slow oxidative (type 1) fiber predominance. We generated a transgenic mouse model to study this disorder by expressing an autosomal dominant mutant of alpha-tropomyosin(slow) previously identified in a human cohort. Rods were found in all muscles, but to varying extents which did not correlate with the amount of mutant protein present. In addition, a pathological feature not commonly associated with this disorder, cytoplasmic bodies, was found in the mouse and subsequently identified in human samples. Muscle weakness is a major feature of this disease and was examined with respect to fiber composition, degree of rod-containing fibers, fiber mechanics and fiber diameter. Hypertrophy of fast, glycolytic (type 2B) fibers was apparent at 2 months of age. Muscle weakness was apparent in mice at 5-6 months of age, mimicking the late onset observed in humans with this mutation. The late onset did not correlate with observed changes in fiber type and rod pathology. Rather, the onset of muscle weakness correlates with an age-related decrease in fiber diameter and suggests that early onset is prevented by hypertrophy of fast, glycolytic fibers. We suggest that the clinical phenotype is precipitated by a failure of the hypertrophy to persist and therefore compensate for muscle weakness.

Amino Acid Substitution↗