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Results for “Muscle Strength”

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At least 469 records · Page 26Linked to original sources

PubMed2006

Factors associated with decreased muscle strength after anterior cruciate ligament reconstruction with hamstring tendon grafts.

PURPOSE: To identify factors associated with decreased muscle strength and activity after anterior cruciate ligament (ACL) reconstruction with semitendinosus-gracilis tendon (ST-G) grafts. TYPE OF STUDY: Retrospective review. METHODS: Eighty-five patients who underwent ACL reconstruction with ST-G grafts were evaluated at a mean of 44.4 months after surgery. Patients underwent isokinetic testing, physical examination, radiographs, instrumented laxity testing, and Lysholm, Cincinnati, and International Knee Documentation Committee (IKDC) ratings. Cartilage and meniscal pathology at surgery was reviewed. Strength group 1 (n = 30) showed greater than 20% deficits in strength; strength group 2 (n = 55) had less than 20% strength deficits. Activity group 1 (n = 60) maintained their IKDC activity level at final follow-up relative to preinjury level; activity group 2 (n = 25) decreased activity by 1 or more levels. RESULTS: With all patients combined, there was less than a 4% difference in mean hamstring and quadriceps strength between the reconstructed and contralateral legs at follow-up. Knee flexion deficits were associated with decreased hamstring strength. Subjective giving way and squatting/kneeling discomfort were associated with decreased quadriceps strength. Patients in strength group 1 were more likely to have squatting/kneeling discomfort and lower Cincinnati Function scores. Activity group 2 had a longer interval from injury to surgery and more chondromalacia at surgery. At follow-up, activity group 2 had lower subjective scores and was more likely to have pain, swelling, giving way, and flexion deficits. Activity group 2 also had greater deficits in quadriceps strength. CONCLUSIONS: Articular cartilage injury and meniscal pathology were not associated with decreased muscle strength. ACL reconstruction with ST-G grafts has a 38% incidence of squatting/kneeling pain that occurs secondary to patellofemoral crepitus, harvest site symptoms, and tibial hardware sensitivity. LEVEL OF EVIDENCE: Level IV, therapeutic, case series, no control group.

Anterior Cruciate Ligament↗

PubMed2005

Muscle strength is a determinant of bone mineral content in the hemiparetic upper extremity: implications for stroke rehabilitation.

Individuals with stroke have a high incidence of bone fractures and approximately 30% of these fractures occur in the upper extremity. The high risk of falls and the decline in bone and muscle health make the chronic stroke population particularly prone to upper extremity fractures. This was the first study to investigate the bone mineral content (BMC), bone mineral density (BMD), and soft tissue composition of the upper extremities and their relationship to stroke-related impairments in ambulatory individuals with chronic stroke (onset >1 year). Dual-energy X-ray absorptiometry (DXA) was used to acquire total body scans on 56 (22 women) community-dwelling individuals (>or=50 years of age) with chronic stroke. BMC (g) and BMD (g/cm2), lean mass (g), and fat mass (g) for each arm were derived from the total body scans. The paretic upper extremity was evaluated for muscle strength (hand-held dynamometry), impairment of motor function (Fugl-Meyer motor assessment), spasticity (Modified Ashworth Scale), and amount of use of the paretic arm in daily activities (Motor Activity Log). Results showed that the paretic arm had significantly lower BMC (13.8%, P<0.001), BMD (4.5%, P<0.001), and lean mass (9.0%, P<0.001) but higher fat mass (6.3%, P=0.028) than the non-paretic arm. Multiple regression analysis showed that lean mass in the paretic arm, height, and muscle strength were significant predictors (R2=0.810, P<0.001) of the paretic arm BMC. Height, muscle strength, and gender were significant predictors (R2=0.822, P<0.001) of lean mass in the paretic arm. These results highlight the potential of muscle strengthening to promote bone health of the paretic arm in individuals with chronic stroke.

Adipose Tissue↗

PubMed1998

Guillain-Barré syndrome, case studies and questionnaire to illustrate junior doctors' awareness of muscle strength testing.

Three patients, aged 7-15 years, with Guillain-Barré syndrome presented with pain as the primary complaint. Two did not complain of weakness and their progressive loss of function was incorrectly ascribed to the pain. One did complain of weakness, in association with flu-like symptoms, but the significance of the complaint was not appreciated. At diagnosis all three had profound, predominantly proximal weakness. We believe the delayed diagnosis relates to doctors' lack of opportunity to examine patients with muscle weakness. We conducted a questionnaire survey of junior hospital doctors asking them about their hands-on experience of testing muscle strength and about their knowledge of the Medical Research Council (MRC) Scale of muscle strength. Doctors who claimed most experience did not have a better knowledge of the MRC scale. We recommend doctors-in-training should be given more opportunity to examine patients with muscle weakness and should be made familiar with a clinical scale of muscle strength.

Adolescent↗

PubMed1987

Effect of parathyroidectomy on respiratory muscle strength in uremic myopathy.

We report the case of a uremic dialysis patient with severe secondary hyperparathyroidism, proximal muscle weakness and impaired respiratory muscle strength, the latter being assessed by maximal inspiratory pressure. After subtotal parathyroidectomy, we observed a marked improvement in respiratory muscle strength (27 vs. 87 cm H2O) and disappearance of proximal muscle weakness.

Adult↗

PubMed1995

Inspiratory muscle strength is a determinant of maximum oxygen consumption in chronic heart failure.

OBJECTIVE: To investigate the significance of respiratory muscle weakness in chronic heart failure and its relation both to maximum oxygen consumption during cardiopulmonary exercise testing and to skeletal muscle (quadriceps) strength. SUBJECTS: Seven healthy men aged 54.9 (SEM 4.3) years and 20 men with chronic heart failure aged 61.4 (1.6) years (P = 0.20) with radionuclide left ventricular ejection fraction of 25.4 (3.0)%. METHODS: Mouth pressures during maximum static inspiratory effort (PImax) at functional residual capacity (FRC) and residual volume (RV) were measured in all subjects and taken as indices of inspiratory muscle strength. Similarly, mouth pressures during maximum static expiratory effort (PEmax) at FRC and total lung capacity (TLC) were taken as indices of expiratory muscle strength. Cardiopulmonary exercise testing was performed in all subjects. All controls and 15 heart failure patients also had their right quadriceps muscle strength measured. RESULTS: There was respiratory muscle weakness in heart failure patients, with reduction of PImax at FRC (59.7) (6.3) v 85.6 (9.6) cm H2O, P = 0.045), PEmax at FRC (94.8 (6.2) v 134.6 (9.1) cm H2O, P = 0.004), and PEmax at TLC (121.7 (8.5) v 160.7 (13) cm H2O, P = 0.028). PImax at RV was also reduced but this did not reach statistical significance (77.3 (6.6) v 89.3 (13) cm H2O, P = 0.44). There was also significant weakness of the right quadriceps muscle (308.5 (22) v 446.2 (28) N, P = 0.001). PImax at both FRC and RV correlated with maximum oxygen consumption (r = 0.59, P = 0.006, and r = 0.45, P = 0.048 respectively) but not PEmax. There was, however, no significant correlation between PImax and right quadriceps strength. CONCLUSIONS: Respiratory muscle weakness is seen in chronic heart failure. The results suggest that inspiratory muscles are important in determining maximum oxygen consumption and exercise tolerance in these patients. The lack of correlation between respiratory and right quadriceps muscle strength further suggests that the magnitude and time course of respiratory and locomotor muscle weakness may differ in individual patients. Treatment aimed at improving the function of the involved muscle groups may alleviate symptoms.

Adult↗

PubMed2004

Is chest expansion a determinant of pulmonary muscle strength in primary fibromyalgia?

OBJECTIVE: To examine the possible relationship between chest expansion and pulmonary muscle strength in patients with primary fibromyalgia (PFM). METHODS: Forty-one consecutive women with PFM were compared with age and body mass index matched 40 healthy women concerning pulmonary function tests, chest expansion, and maximum respiratory pressures indicating pulmonary muscle strength, and endurance (MVV). Pain was scored according to a visual analog scale (VAS). Chest pain was scored on a 10 point scale. RESULTS: There was no significant difference between the two groups regarding chest expansion (P > 0.05). Maximum inspiratory and expiratory pressures (MIP, MEP) were lower in fibromyalgia patients than controls (P < 0.05). However, chest expansion and dyspnea score were insignificant between groups (P > 0.05). CONCLUSION: Reduced maximum respiratory pressures (MIP, MEP) may result from isometric type pulmonary muscle dysfunction as a result of low physical performance in fibromyalgia patients, despite insignificant finding of chest expansion and dyspnea score according to controls.

Adult↗

PubMed1998

Muscle strength in individuals with healed burns.

OBJECTIVE: To quantify the long-term effects of burns on muscle strength and to investigate the impact of the initial severity of the trauma on muscle strength. DESIGN: Cross-sectional study comparing individuals with healed burns to nonburned control individuals matched for age, gender, body mass index, and physical activity level. SETTING: Subjects were selected from the data bank of a burn center of a large Montreal teaching hospital and tested in a university laboratory. PATIENTS: Thirty subjects (mean age, 36.3 +/- 11.5 yrs) with second- and third-degree burns covering 15% to 75% of total body surface area (TBSA) (mean, 35.5% +/- 15.9%) were evaluated more than 1 year after discharge (mean, 37.3 +/- 20.4 months; range, 15 to 92 months). Thirty unburned subjects were recruited from the community at large. MAIN OUTCOME MEASURE: Maximal torque, work, and power developed by the elbow and knee flexors and extensors. RESULTS: Subjects with burns of > 30% of TBSA produced significantly less torque, work, and power in the quadriceps than control subjects (15.2% to 20.5% depending on velocity [p < .05]). The ability to develop muscle power at the elbow was also compromised in the severely burned subjects (19.2% in extension and 18.7% in flexion [p = .07]) at the faster velocities. No differences were observed between controls and patients with small burn injuries (TBSA of < 30%). CONCLUSION: Patients who had severe burns (TBSA of > 30%) had weaker muscles even years after the trauma, suggesting either an inability to fully recover or insufficient rehabilitation.

Adult↗

PubMed1993

Neuromuscular adaptations during the acquisition of muscle strength, power and motor tasks.

Neuromuscular performance is determined not only by the size of the involved muscles, but also by the ability of the nervous system to appropriately activate the muscles. Adaptive changes in the nervous system in response to training are referred to as neural adaptation. This article briefly reviews current evidence regarding the neural adaptations during the acquisition of muscle strength power and motor tasks and will be organized under four main topics, namely: (i) muscle strength gain: neural factors versus hypertrophy, (ii) neural adaptations during power training, (iii) neuromuscular adaptations during the acquisition of a motor task, and (iv) neuromuscular adaptations during a ballistic movement.

Adaptation, Physiological↗

PubMed2005

Non-invasive assessment of respiratory muscle strength in patients with previous poliomyelitis.

UNLABELLED: In patients with poliomyelitis, respiratory failure requiring ventilatory support may occur during the acute illness. Some patients continue to require long-term nocturnal ventilatory support; others are weaned but subsequently require support because of a late deterioration in ventilatory function. OBJECTIVES: To assess the sensitivity of sniff nasal inspiratory pressure (SNIP) to post-poliomyelitis respiratory muscle weakness and to assess the relationship between the respiratory muscle strength and the need for ventilatory support in patients with previous poliomyelitis (post-polio patients). METHODS: Respiratory muscle strength was measured in 50 post-polio patients. Tests included forced vital capacity (FVC), maximum inspiratory and expiratory pressures (MIP and MEP), and SNIP. RESULTS: Twenty-one patients used non-invasive nocturnal ventilatory support (NIV group) compared to 29 on no support (non-NIV group). The percentage predicted FVC was significantly lower in the NIV group compared to the non-NIV group (P=0.01). Similarly, the percentage predicted MIP was significantly lower in NIV group (P=0.007). Low SNIP values (both absolute value and percentage predicted) were associated with the need for ventilatory support (P<0.001). Of the patients requiring no support, those who had been ventilated during the acute episode of poliomyelitis had a significantly lower SNIP than those who had never been ventilated (P=0.04). CONCLUSIONS: Post-polio patients who are currently on nocturnal ventilation have significantly lower FVC, MIP and SNIP compared to currently non-ventilated patients. Non-ventilated patients who were ventilated during the acute episode of poliomyelitis have significantly weaker respiratory muscle strength than patients who were never ventilated. This study indicates that SNIP is more sensitive to post-polio respiratory muscle weakness than other non-invasive tests. Thus measurement of SNIP is a valuable tool for monitoring the progression of respiratory muscle weakness due to previous poliomyelitis and this can be applied to other neuromuscular disorders.

Acute Disease↗

PubMed1998

Intertester reliability of manual muscle strength testing in leprosy patients.

This study reports the results of a study on the intertester reliability of manual muscle strength testing in leprosy patients with confirmed motor function loss of at least one nerve. Three testers graded the muscle strength of 72 patients in random order. Both hands and feet were graded. Strength was graded on a modified Medical Research Council Scale (9 points, 5, 4+, 4, 3+, 3, 2+, 2, 1, 0). The following movements were tested for strength: little finger and index finger abduction, intrinsic position of all four fingers, thumb abduction and opposition, foot dorsiflexion and eversion and extension of the big toe. The weighted kappa statistic was used to calculate the chance-corrected percentage of agreement between observers. Overall agreement for each of the 11 tests appeared to be good or very good (0.61-1.00). However, when data for hands or feet with normal strength or complete paralysis were excluded from the analysis, the reliability of the remaining mid-range scale was not acceptable (kappa 0.55-0.88, direct agreement range 11-41%). While the reliability of this scale could possibly be improved by special training, we feel that, for the evaluation of nerve function for leprosy patients with (suspected) nerve function loss, the extended 9-point VMT scale should only be used when direct intra- or intertester agreement is more than 80%.

Female↗

PubMed1982

Respiratory muscle strength and maximal voluntary ventilation in undernourished patients.

To assess the effect of chronic debilitation on respiratory muscle function, we studied 16 poorly nourished (PN) patients without pulmonary disease, and 16 well-nourished (WN) subjects matched for age and sex. Body weight, vital capacity (VC), maximal voluntary ventilation (MVV), and maximal static inspiratory and expiratory pressures (PImax and PEmax) were measured and expressed as percent predicted. Respiratory muscle strength (RMS) was calculated as (% PImax + % PEmax)2. Body weight was 71% predicted in the PN group and 104% in the WN group. The RMS, MVV, and VC were 37%, 41%, and 63%, respectively, of the values in the WN group (p less than 0.001). The 60% reduction in RMS was shared almost equally among inspiratory and expiratory muscles, and PEmax was linearly related to body weight. Because malnutrition reduces both respiratory muscle strength and MVV, it may well impair respiratory muscle capacity to handle increased ventilatory loads in thoracopulmonary disease.

Adolescent↗

PubMed1999

Quantitative assessment of cross-sectional muscle area, functional status, and muscle strength in men with the acquired immunodeficiency syndrome wasting syndrome.

The acquired immunodeficiency syndrome wasting syndrome (AWS) in men is characterized by the loss of lean body mass out of proportion to weight. Although the wasting syndrome has been thought to contribute to reduced functional capacity, the relationships among lean body mass, muscle size, functional status, and regional muscle strength have not previously been investigated in this population. In this study, 24 eugonadal men with the AWS (weight <90% of the ideal body weight or weight loss >10% from preillness maximum) underwent determination of body composition by dual energy x-ray absorptiometry (DXA), 40K isotope analysis, urinary creatinine excretion, and quantitative computed tomographic analysis of cross-sectional muscle areas of the midarm and thigh. Overall exercise functional capacity was evaluated using the 6-min walk test, and performance of upper and lower extremities was determined with the quantitative muscle function test. Subjects were 37 +/- 1 yr of age and weighed 95.5 +/- 3.0% of ideal body weight, with a body mass index of 21.9 +/- 0.7 kg/m2 and an average weight loss of 15 +/- 1%. The mean CD4 count among the subjects was 354 +/- 70 cells/mm3, and viral load was 58,561 +/- 32,205 copies. Sixty-two percent of subjects were receiving protease inhibitor therapy. The subjects demonstrated 90% of the expected muscle mass by the creatinine height index method. Overall performance status on the Karnofsky scale was highly correlated to weight (r = 0.51; P = 0.018; by body mass index), lean body mass (r = 0.46; P = 0.036; by DXA), and body cell mass (r = 0.47; P = 0.037; by 40K isotope analysis). Cross-sectional muscle area of the upper extremity was the best predictor (P < 0.001) of Karnofsky score, accounting for 52% of the variability in a stepwise regression analysis. Upper body muscle strength was most significantly predicted by lean body mass (by DXA; r2 = 0.78; P < 0.0001), whereas lower body strength and performance on the 6-min walk test were best predicted by lower extremity cross-sectional muscle area (r2 = 0.70; P < 0.0001 and r2 = 0.26; P = 0.030, respectively). These data demonstrate that cross-sectional muscle area is highly predictive of functional status and muscle strength in men with the AWS.

Adult↗

PubMed1981

Isokinetic thigh muscle strength after ligament reconstruction in the knee joint: results from a 5-10 year follow-up after reconstructions of the anterior cruciate ligament in the knee joint.

We evaluated the thigh muscle strength using an isokinetic dynamometer in 80 patients 5 to 10 years following anterior cruciate ligament reconstruction. Patients with good results also had good muscle function, both of their flexor and their extensor muscles. Patients with poor results demonstrated reduced muscle strength in both their hamstrings and their quadriceps. Patients with fair functional results demonstrated reduced strength of their extensor muscles compared to their normal leg. However, strength in their operated leg's flexor muscles was unchanged compared to their normal leg. This may be due to the fact that strong hamstring muscles can compensate for some instability of the anterior cruciate ligament.

Adolescent↗

PubMed1989

Effects of upper limb immobilization on isometric muscle strength, movement time, and triphasic electromyographic characteristics.

The effects of short-term immobilization on isometric muscle strength, movement time, and triphasic integrated electromyographic characteristics were assessed during a simple ballistic elbow flexion and extension movement. The nondominant upper limbs in six subjects (two female, four male) were immobilized in a plaster cast for 14 days. Testing consisted of isometric muscle strength output of elbow flexors and extensors; movement time; and IEMG output of the agonist, antagonist, and second agonist contractions during the ballistic movements. An analysis of variance revealed a decrease in flexor strength of the casted limb (p less than .05). Movement time was not significantly slowed. Antagonist IEMG amplitude was decreased (p less than .01) during flexion, and agonist IEMG amplitude (p less than .05) and antagonist IEMG amplitude (p less than .05) were diminished during extension of the casted limb. In conclusion, short-term upper limb immobilization affects primarily elbow flexion strength and some IEMG characteristics during a ballistic forearm movement, suggesting an influence on the neuromuscular aspects of the affected muscles.

Adult↗

PubMed1995

A developmental index of muscle strength and assessment of quadriceps function in children with spina bifida.

This study was designed to develop a new index of muscle strength for children that was independent of body weight thus accommodated their developmental changes and to assess the quadriceps strength influencing ambulatory status in children with spina bifida. Maximum voluntary strength in isometric knee extension was measured from 60 children with spina bifida and 92 normal children. The measured strength was described in terms of torque. A muscle strength index (MSI) was defined as a unitless measure independent of the subject's body weight (i) by normalizing the residual of the maximum torque from the developmental regression line for normal children by body weight and, furthermore, (ii) by dividing the normalized residuals by their standard deviation among normal children. Children with spina bifida demonstrated a tendency to increase in maximum quadriceps torque with body weight; however, spina bifida children with a body weight above 30 kg showed a progressive decrease in MSI below a normal limit of muscle weakness. The MSI was closely related to both neurologic level and ambulatory ability compared with the maximum torque. These findings suggest MSI provides useful and detailed information for assessing and predicting ambulatory ability in children with spina bifida.

Adolescent↗

PubMed2006

Tutorial on maximum inspiratory and expiratory mouth pressures in individuals with idiopathic Parkinson disease (IPD) and the preliminary results of an expiratory muscle strength training program.

Respiratory symptoms are recognized as sequelae of motor dysfunction in idiopathic Parkinson's disease (IPD) and these symptoms have the potential to cause problems with swallow, cough, voice and speech. Specifically, maneuvers that require rapid activation and coordination of upper airway and chest wall musculature become progressively impaired as motor dysfunction progresses during the natural course of the disease. This study reports on the maximum inspiratory and expiratory pressures produced by 28 participants (average age 64) diagnosed with moderate to severe IPD (average stage 2.5 with a range of 2.0-3.0). All measures were collected during the "medication on" state. Outcomes of a specific respiratory muscle strength training technique for improving maximum expiratory pressure are reported for three of the patients in this study. Techniques that focus on strengthening the respiratory muscles in patients with IPD (other than with low load breathing exercises), have not been previously reported. The results of this pilot study demonstrate that respiratory muscle weakness may be an important factor in the respiratory complications in IPD and that respiratory muscle strength training has the potential to improve expiratory muscle strength for this population. This improvement has the potential to positively impact high forced respiratory activities, such as forced breathing maneuvers, swallow, cough and speech functions that require greater magnitude and duration of expiration.

Adult↗

PubMed1986

Muscle strength testing in Parkinson's disease.

Isotonic muscle strength measured by a quantitative technique was decreased in early Parkinson's disease compared to age-matched controls. Weakness was present both on the affected and unaffected side in hemiparkinsonism. Similar degrees of weakness occurred in limbs with tremor or rigidity. Muscle weakness appears to be a primary symptom of Parkinson's disease which may relate to disturbed motor programming due to basal ganglia dysfunction.

Arm↗

PubMed1980

Skeletal muscle strength during exposure to hypobaric hypoxia.

To assess the effects of acute exposure to hypobaric hypoxia and acute mountain sickness (AMS) on skeletal muscle strength, 10 healthy young men were studied before, during, and after a 48-h sojourn at a simulated altitude of 4,572 m (15,000 feet). Measurements were made of isokinetic (180 degrees, 36 degrees, and 0 degrees/s) knee extensor strength; isometric strength of upper torso, knee, and trunk extensor muscles; and strength endurance of knee extensor and elbow flexor muscles during a bout of repeated isokinetic contractions. There were no significant differences between strength measurements at sea level and after 2 and 24 h of hypoxic exposure. After 48 h of exposure, means of strength measurements were increased relative to sea-level values but the difference was statistically significant in the case of only one test; namely, isometric strength of the upper torso. Strength endurance was unchanged throughout the exposure. Symptoms of AMS were absent after 2 h, most pronounced after 24 h, and although somewhat reduced, still present to a significant extent after 48 h of hypoxia. Thus, despite the occurrence of AMS, muscle strength was unimpaired during acute hypoxic exposure.

Adult↗