More on muscle strength measurement.
Explore the source record for details and available documents.
SEARCH · PubMed Health
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.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The influence of sex, age, and socioeconomic conditions on specific grip strength of 6-18-year-old individuals was studied among 1,704 males and 1,956 females belonging to the so-called "Cape Coloured" community in the western part of South Africa. Half of the participants of both sexes came from communities in the Greater Cape Town area where living conditions are comparable to those of middle-class First World communities (high SES). The other half came from the poorest rural communities of Klein Karoo (low SES). Arm circumferences, triceps skinfold thickness, and grip strength of the right and of the left hand were greater in individuals from high SES at all ages. Females within each SES group had skinfolds thicker than males, especially at older ages, and were weaker. Specific grip strength (SS), estimated as grip strength per unit area of cross section of the fat-free arm, increased with age in each group, was greater in males, and was significantly lower in low SES groups, than in the high SES ones, especially during and after puberty. It seems that SES difference in SS will persist into adulthood. Sexual differences in SS can be attributed to hormonal differences; while the SS increase with age and the difference between SES groups find no clear explanation in current theories of muscle growth and development. Since the speed of neuromuscular reaction observed in our participants is slower among low SES individuals, it seems that the difference in neuromuscular control of strength may be responsible for our findings. Differences in muscle metabolism and hormonal regulation must also be considered.
Eleven arthritic knee joints in seven patients with rheumatoid arthritis were studied before and after intraarticular injection of a corticosteroid preparation. Extensor muscle torque and quantitative electromyography increased on days 7 and 14 after treatment, indicating that muscle function had been inhibited by synovitis. Clinical signs of synovitis, such as pain, range of motion and knee circumference, also improved. Synovial fluid withdrawal alone improved extensor muscle torque. Joints with instability and/or radiological cartilage involvement also improved.
We examined 26 spinal muscular atrophy type III (SMA III) patients with SMNt deletions, searching for possible segmental distribution of muscle weakness. In those with disease duration of < or = 11 years, the weakest muscles were upper lumbar innervated ones in the lower extremities. In the upper extremities, early involvement of triceps muscle suggested the possibility of lower cervical (C7) onset. Electrophysiologically, weaker muscles had a more severe reduction in the recruitment pattern, particularly in the lower extremities. However, severe reduction in recruitment was sometimes also observed in clinically strong muscles. In patients with disease duration of > or = 16 years and regardless of disease duration, in those with disease onset at < or = 3 years of age, weakness and severe electrophysiological changes were more widespread. These findings may suggest a progression in muscle weakness with time. When compared to 12 patients with Becker muscular dystrophy (BMD), early stage SMA III with weak iliopsoas-strong gluteus maximus stood in contrast to BMD with weak gluteus maximus-strong iliopsoas.
In the present study isokinetic dynamometry was used to evaluate the capacity for dynamic knee joint stabilization via muscle contraction in elite sailors (15 males, SM; 6 females, SF) compared to a group of matched controls (8 males, CM). Maximal concentric, eccentric and isometric moment of force (peak moment and moment at 50 degree knee flexion) was obtained for the knee extensors (quadriceps) and flexors (hamstrings) during isokinetic knee joint movement at angular velocities 0, 30, 120 and 180 degrees x s(-1). High levels of eccentric knee extension strength were observed for the elite sailors compared to the controls (p < 0.05). Based on peak moment and 50 degree moment, respectively, conventional hamstring/quadriceps (H/Q) strength ratio (+/-SD) ranged from 0.37+/-0.06 to 0.54+/-0.06 and from 0.42+/-0.07 to 0.57+/-0.10 across groups, speed and contraction mode. The female elite sailors displayed lower (p<0.05) concentric H/Q ratios at 120 and 180 degrees x s(-1) compared to the controls (0.41-0.45 vs. 0.51-0.56, respectively). The ratio of eccentric hamstring to concentric quadriceps strength (H/Q for extension) or concentric hamstring to eccentric quadriceps strength (H/Q for flexion) may provide a more functional estimate of the capacity for muscular knee joint stabilization (1). Based on peak moment and 50 degree moment, respectively, this "functional" H/Q ratio ranged from 0.24+/-0.03 and 0.25+/-0.02 for knee flexion at 180 degrees x s(-1) to 0.97+/-0.17 and 0.88+/-0.12 for knee extension at 180 degrees x s(-1) among the three groups. Comparable levels of "functional" H/Q ratio were observed (p>0.05) for fast knee extension in the elite sailors (SF:0.81-0.97, SM: 0.88-0.95) and the male controls (CM: 0.80-0.84). In conclusion, a "functional" H/Q ratio of 0.8-1.0 observed for all subjects indicated a significant functional capacity of the hamstring muscles for providing muscular stability at the knee joint in fast knee extension. A significant potential for muscular knee joint stabilization appeared for the elite sailors despite their high maximal quadriceps strength and partially lower (SF) conventional H/Q ratios.
OBJECTIVE: The study was undertaken in order to evaluate the effect of magnesium (Mg) supplementation on muscle contents of Mg, muscle strength, muscle mass and sodium, potassium pumps (Na,K-pumps) in patients with alcoholic liver disease. Retrospectively, patients were also stratified according to spironolactone treatment. MATERIAL AND METHODS: The study comprised a placebo-controlled, randomized trial in which 59 consecutive patients with alcoholic liver disease were treated with Mg intravenously and orally (12.5 mmol daily) or placebo for 6 weeks. Muscle content of Mg, maximum isokinetic muscle strength, skeletal muscle mass and muscle content of Na,K-pumps were measured before and after Mg supplementation. RESULTS: Muscle Mg did not increase during the trial (paired t-test), but Mg supplementation and the duration of pre-study spironolactone treatment were independent predictors of muscle Mg (multiple regression). Muscle strength increased by 14% during the trial (p<0.001) and muscle mass increased by 11% (p=0.05), but with no difference between placebo and Mg treatment. Spironolactone treatment was associated with a 33% increase in the content of Na,K-pumps (p<0.001). CONCLUSIONS: Six weeks of Mg supplementation did not increase muscle Mg, although Mg supplementation and spironolactone treatment were independent predictors of muscle Mg. The intervention had no effect on muscle strength and mass, but both increased during the study, probably owing to the general care and attendance to the patients.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Since the number of elderly people with a sedentary lifestyle is considerable and still growing, regular exercise could be an extra stimulant to compensate for the decrease in functional capacities. The potential positive effects of physical and sporting activities (PSA) on muscular function in relation to the period of practice were studied. Muscular strength and power were evaluated by dynamometric knee and ankle tests on 40 healthy subjects aged over 60 years old, split into four groups according to the period of practice. Higher muscular performance was obtained in subjects who had always practised PSA, whereas subjects who had always been inactive displayed the worst muscular performances. Subjects who had begun PSA practice lately had good muscular strength and power, close to those of the AA group, whereas the subjects who had stopped the practice at an early age did not perform as well. Life-long PSA attenuates the age-related loss of muscle function, and initiation at old age improves it. This, and the absence of any beneficial effects of PSA stopped when young, indicates that the actual activity level is an important determinant of skeletal muscle function at old age. Practicing PSA increases muscular strength and power and thus improves daily living activities in elderly people.