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PubMed2003

The effects of a neuromuscular electrical stimulation home program on impairments and functional skills of a child with spastic diplegic cerebral palsy: a case report.

PURPOSE: To examine the effects of neuromuscular electrical stimulation (NMES) on impairments and functional skills of a 13-year-old child with spastic diplegic cerebral palsy (CP). METHODS: NMES was administered to the right quadriceps muscles every other day for six weeks. Pre- and posttesting included assessment of strength using a hand-held dynamometer, spasticity using a KinCom isokinetic dynamometer, gait spatiotemporal parameters using GAITRite, and functional motor performance with the use of the Pediatric Evaluation of Disability Inventory (PEDI). RESULTS: After intervention, right quadriceps strength increased from 16.3 +/- 3.06 to 41.7 +/- 4.2 Newtons. Right hamstring spasticity decreased at three tested velocities. In the untreated left lower extremity, strength remained unchanged but spasticity increased. The PEDI showed development of new skills, including the ability to climb stairs with less assistance. CONCLUSION: These findings indicate that NMES was an effective therapeutic technique to improve strength and motor function of a child with spastic diplegic CP.

Journal Article↗
PubMed1990

Relationships of body size, segmental dimensions, and ponderal equivalents to muscular strength in high-strength and low-strength subjects.

There are conflicting results in prior studies concerning the relationships among body size, muscle size, and muscular strength. The purpose of the present study was to evaluate how body size, body shape, and segmental dimensions related to individual differences in muscular strength. Subjects were tested on four dynamic measures of strength and then classified into one of two groups as high strength (HS; N = 21) and low strength (LS; N = 21). Individual differences in strength were then related to body composition and segmental anthropometry. Strength was assessed during high-resistance, low-velocity standing squat and supine bench press with an isokinetic dynamometer, and during seated bench press and knee extension with a hydraulic resistance dynamometer. Anthropometry and body composition included 11 girths, six fatfolds, predicted fat-free mass (FFM), thigh and upper arm volume, muscle + bone cross-sectional area (CSA), and the Behnke Ponderal Somatogram (PSom) body profiling system. There was a 21.3% difference in strength between HS and LS (p less than 0.05), but no significant differences in age, stature, and fatfolds. MANOVA revealed that seven of 11 girth components of PSom were larger for HS (p less than 0.05). The correlations between strength vs body mass, FFM, thigh and upper arm volume, and CSA and fatfolds in HS and LS ranged from r = -0.52 to 0.56 (r = -0.70 to 0.70 when corrected for restriction of range). We conclude that individual differences in muscular strength are poorly related to various measures of body size and segmental body dimensions.

Adult↗
PubMed1994

Comparison of a hand-held and fixed dynamometer in measuring strength of patients with neuromuscular disease.

While numerous studies report acceptable reliability of hand-held dynamometers, very little information is available on factors affecting measurements and comparisons with other force measurement systems. A hand-held dynamometer was compared to a fixed dynamometer to determine if the two systems of force measurement yielded comparable results. Twenty-one patients with neuromuscular disease were measured for maximal isometric strength of 12 muscle groups with both force measurement systems using standardized positioning and stabilization procedures. Only one of the 12 muscle groups tested demonstrated significantly different force measurements between the two systems. Good association was found between both systems in force measurements, with Pearson correlation coefficients ranging from .76 to .90. We conclude that a hand-held dynamometer and a fixed dynamometer yield comparable results in patients with neuromuscular disease, provided that testing is limited to muscle groups producing relatively low forces.

Adult↗
PubMed1997

Influences of muscle stretch reflexes on voluntary, velocity-controlled movements in spastic paraparesis.

We studied voluntary, velocity-controlled knee movements in 22 patients with spastic paraparesis (11 male, 11 female) and 22 healthy controls (11 male, 11 female). Torque and EMG activity of the quadriceps and the hamstring muscles were determined in maximal voluntary concentric (shortening) and eccentric (lengthening) actions of knee extensor and flexor muscles at constant movement velocities of 30, 60, 120 and 180 degrees/s, using an active, isokinetic dynamometer. In the spastic patients, the voluntary strength and the agonist EMG activity were reduced in all movements. The reduction was largest in concentric actions at high velocity. The antagonist EMG activity was reduced in the same proportion as the agonist EMG activity in eccentric actions. In concentric actions when stretch is imposed upon antagonists, the antagonist EMG activity increased with the velocity of stretch, indicating stretch reflex activation. In parallel with the stretch reflex activation of antagonists, there was reduced activation of the agonists compatible with Ia reciprocal inhibition of agonist motoneurons. When agonists were stretched in eccentric actions, stretch reflexes appeared to support the voluntary, agonist activation of knee flexor muscles but not knee extensors.

Adult↗
PubMed1999

Isokinetic muscle performance after surgery of the lateral ligaments of the ankle.

In this study, we assessed the isokinetic strength and power profile of 138 patients with a surgically treated lateral ligament injury of an ankle. In addition, the outcome predicting factors were analyzed. The measurements were done 6.2+/-0.8 years after the surgery using the Cybex II isokinetic dynamometer. The general strength status of the patients was good, the isokinetic testing showing no or only moderate (always < or = 18%) average strength deficits in the peak torque values of dorsiflexor and plantar flexor muscles of the injured ankle. Of the outcome predicting variables, only the age of the patient in the group with surgery for chronic ankle instability correlated significantly with the isokinetic peak torque deficits: the older the subject, the greater the peak torque deficit in the injured ankle (r(s) = -0.388 with p = 0.015) in ankle dorsiflexion at the speed of 60 degrees/s. In conclusion, patients having surgery for ankle ligament insufficiency, either in acute or chronic phase of the injury, seem to recover well showing no remarkable deficiencies in the isokinetic ankle muscle strengths several years after the repair.

Acute Disease↗
PubMedDate not supplied

Hand-grip dynamometry provides a valid indication of upper extremity strength impairment in home care patients.

This retrospective study investigated the validity of hand-grip dynamometry with respect to its use in predicting generalized upper extremity strength. The records of 37 patients (mean average age, 77.7 years) receiving home care were used. Discriminant construct validity was examined by comparing their dynamometry measurements with measurements of age- and gender-matched healthy individuals reported in the literature. Convergent construct validity was described by the correlations of their dynamometry measurements and manual muscle test scores of the upper extremities. The patients' dynamometer-measured grip forces were significantly less than reported normative values. The patients' dynamometer measured grip forces were correlated significantly with their manual muscle test scores. These findings support the construct validity of hand-grip dynamometry for characterizing upper extremity strength impairment among adults treated in a home care setting.

Aged↗
PubMed1999

Changes in muscle strength in women following the menopause: a longitudinal assessment of the efficacy of hormone replacement therapy.

The effects of hormone deficiency at the menopause on muscle strength was examined in 10 healthy middle-aged women (1-3 years post-menopause) in a longitudinal trial over 39 weeks. Performance was compared with that of age-matched females (n=11) taking a course of hormone replacement therapy (HRT). Muscle strength of the quadriceps was measured isometrically at 90 degrees of knee flexion and at angular velocities of 1.05, 2.09 and 3.13 rad/s using an isokinetic dynamometer. Hand grip strength was assessed by means of a portable dynamometer. Measurements were taken every 13 weeks for 39 weeks. Significant decreases in isometric strength (-10%) and dynamic leg strength at 1.05 rad/s (-9%) were found in the post-menopausal women over 39 weeks. There was no change in strength in the HRT group. There were also no changes in leg strength at higher angular velocities or in grip strength for either the post-menopausal group or those taking HRT. While HRT preserved muscle strength, there was no evidence of a strengthening effect on skeletal muscle within this short period of treatment. A rapid loss of leg strength occurs post-menopausally in hormone-depleted women. HRT may offer protection against muscle weakness, although the hormone responsible for regulating strength is not evident using this model.

Exercise↗
PubMed1993

Normal values for handgrip strength in 920 men and women aged over 65 years, and longitudinal changes over 4 years in 620 survivors.

1. The maximal grip strength of the hand has been measured in a random sample of 359 men and 561 women aged over 65 years living in their own homes. The response rate was 80% from a representative demographic area of the U.K. Measurements were made of body mass, skeletal size (demispan) and grip strength. Grip strength was measured using a custom-built strain-gauged dynamometer. The best of three attempts was taken as definitive. A structured questionnaire was used to obtain information about customary activity, use of handgrip muscles, health and psychological well-being. This was repeated with 620 survivors 4 years later. 2. The results for strength were normally distributed. The right hand was 10% stronger than the left and men had twice the strength of women. Strength was significantly related to skeletal size and in men to body mass. The gender difference was only partly accounted for by skeletal size and women were substantially disadvantaged in terms of their strength/body mass ratio. 3. There was a significant decline in strength with age of 2%/year for men and women. Strength was also significantly related to customary activity, reported use of the hands and psychological and physical health. 4. After 4 years 620 survivors were re-measured. Grip strength had declined by 12% in men and 19% in women and these losses were significantly related to age. A significant decline was also found in reported use, customary activity and health scores, and in women in body mass and psychological health.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed2005

Dorsal double-plate fixation of the distal radius.

OBJECTIVE: Restoration of the intra- and extraarticular anatomy of the distal radius. Stable internal fixation of fragments, with the possibility of early functional rehabilitation. INDICATIONS: Distal intraarticular radius fractures with impacted articular fragments and displaced dorsoulnar fragment. Distal intraarticular radius fractures with bony or ligamentous injury of the proximal carpal row. CONTRAINDICATIONS: General medical contraindications for surgical intervention. Distal radius fractures with palmar tilt of the distal fragment. SURGICAL TECHNIQUE: Dorsal longitudinal incision. Approach to the intermediate column via the third extensor compartment by detaching the extensor pollicis longus (EPL) tendon. Arthrotomy and revision of the proximal carpal row. Reconstruction of the radiocarpal articular surface and support with a plate applied to the dorsoulnar aspect. Approach to the radial column by subcutaneous preparation between skin flaps (cave: superficial branch of the radial nerve) and retinaculum, incision of the first extensor compartment and support of the radial column with a preshaped plate, which is pushed through under the tendons of the first compartment. Cancellous bone grafting is usually not necessary. Subcutaneous displacement of the EPL tendon with the aid of a small retinacular flap. MANAGEMENT RESULTS: Application of a removable velcro cuff. Immediate functional postoperative physiotherapy, without the cuff. No straining or forcing until first radiographic examination at 6 weeks after the operation. RESULTS: 25 consecutive patients were monitored following a double-plate fixation, with a minimum follow-up of 12 months. In all cases the reduction, in accordance with the Stewart Score, was very good, a loss of reduction was not observed. The range of motion was between 100 degrees and 160 degrees for flexion/extension and between 160 degrees und 180 degrees for pronation/supination. The average DASH Score was 7.2 points, the PRWE Score 8.0 points. No relevant loss of strength (JAMAR dynamometer) was found in any of the patients in comparison with the healthy side. Complications noted were a muscle adhesion in the region of the first extensor compartment as well as a mild reflex sympathetic dystrophy, which healed without consequences. Implants were removed from six of the patients.

Adolescent↗
PubMed2002

Relation between spasticity and strength in individuals with spastic diplegic cerebral palsy.

The relation between spasticity and strength in individuals with cerebral palsy (CP) has not been extensively researched. Knee and ankle spasticity and strength were quantified in a retrospective analysis of 60 individuals with spastic diplegic CP (mean age 12 years, range 3 to 38) and a group of 50 individuals without disabilities (WD group; mean age 12 years, range 4 to 36). Spasticity was measured using a KinCom dynamometer that stretched the passive knee flexors or ankle plantarflexors at different speeds and recorded the amount of resistive torques. For the strength tests, the participant performed a maximum contraction of the knee flexors/extensors and ankle plantarflexors/dorsiflexors throughout their range of motion at a speed of 10 degrees/s on the dynamometer. Pearson's correlation coefficient was used to determine if a relation existed between spasticity and strength within the same muscle group and in opposing muscle groups at the knee and ankle joints. A t-test was performed to determine if greater spasticity and less strength existed at the ankles compared with the knees in those with CP. Results show that there was no relation between spasticity and strength either within the same muscle group or at opposing muscle groups at the knee and ankle joints in persons with CP. Individuals with spastic diplegic CP were more involved (greater spasticity, less strength) distally at the ankles compared with the knees. The findings conflict with the literature, which contains several assumptions, one of which is that a spastic muscle is a strong muscle and that spasticity causes weakness in the opposing muscle group. We found no relation between spasticity and strength in individuals with CP. Our findings support the literature, which states that individuals with spastic diplegic CP are more involved distally compared with proximally in the lower extremities.

Adolescent↗
PubMedDate not supplied

Results of a triple blind clinical study of myoblast transplantations without immunosuppressive treatment in young boys with Duchenne muscular dystrophy.

The effects of myoblast transplantations without an immunosuppressive treatment on muscle strength, and the formation of dystrophin-positive fibers was studied in five young boys with Duchenne muscular dystrophy (DMD) using a triple blind design. Injections of myoblasts were made into one biceps brachii (BB), and the opposite BB, used as a control, was sham-injected; the experimenters and the patient were blind to the myoblast-injected side. At the same time, myoblasts were also injected in the left tibialis anterior (TA) of these patients. The strength developed during maximal static contractions of the elbow flexor and extensor muscles was measured with a Kin-Com dynamometer. No increase in static elbow flexion torque was measured at any time from 2 mo up to 18 mo after the transplantation. One month after the transplantation, the percentage of dystrophin-positive fibers in the myoblast-injected TA ranged from 0 to 36%, while it ranged from 0 to 4% on the control side. The expression of dystrophin in these fibers, however, was generally low, and most likely less than 10% of the normal level. In the biceps brachii of both sides 6 mo after the transplantation, less than 1.5% of dystrophin-positive fibers were detected. The injections also triggered a humoral immune response of the host. Antibodies were capable of fixing the complement, and of lysing the newly formed myotubes. One of the antigens recognized by this immune response is possibly dystrophin. These results strongly suggest that myoblast transplantations, as well as gene therapy for DMD, cannot be done without immunosuppression.

Biopsy↗
PubMedDate not supplied

Muscle activation and force production during bilateral and unilateral concentric and isometric contractions of the knee extensors in men and women at different ages.

In experiment I ten young men (29 +/- 3 yrs; M30), 12 middle-aged men (50 +/- 4 yrs; M50) and 12 women (48 +/- 5 yrs; W50), 12 elderly men (67 +/- 4 yrs; M70) and 12 women (68 +/- 4 yrs; W70) volunteered for subjects for examination of maximal 1 RM strength and electromyographic activity of the knee extensor muscles during the bilateral and unilateral concentric contraction on a variable resistance knee extension dynamometer. In experiment II 10 young (Y) men (29 +/- 5 yrs) and 10 older (O) men (61 +/- 4 yrs) were examined for their maximal voluntary isometric force and force-time curves and electromyographic activity of the knee extensor muscles during the bilateral and unilateral contractions. The bilateral 1 RM of 165.5 +/- 25.5 kg in M30 was greater (p < 0.01) than that of 127.7 +/- 24.5 kg recorded for M50 the latter being also greater (p < 0.05) than that of 109.0 +/- 17.7 kg recorded for M70. The bilateral value of 87.4 +/- 13.4 kg in W50 was greater (p < 0.05) than that of 69.9 +/- 15.0 kg recorded for W70. The bilateral 1 RM values were slightly greater than the summed unilateral 1 RM values in all groups M50, W50 and W70 showing a significant (p < 0.05) difference. All groups showed slightly (ns.) greater mean maximal integrated EMG values during the bilateral conditions in comparison to that of the corresponding unilateral condition. The maximal isometric forces in Y men were 25% greater (p < 0.001) than in O men. In both groups the bilateral forces were somewhat greater (p < 0.05) than the summed unilateral forces and the bilateral IEMG values slightly (ns.) greater than the corresponding unilateral IEMG values. The early forces on the force-time curve were much greater (p < 0.05-0.001) in Y than O men in both conditions. The present findings suggest that both maximal voluntary isometric and concentric force, and especially explosive strength of the knee extensors decrease greatly with increasing age probably due to selective muscle atrophy and/or possible decreases in the amount or rate of voluntary activation of the muscles. However, no bilateral deficit could be found indicating that the central nervous system in a simple single joint isometric and maximal 1 RM concentric force production of the knee extensors was capable of activation of the two bilateral muscle groups simultaneously independent of age and sex of the subject. To which extent the activation and force production of the muscles would be different in terms of the bilateral deficit during various multijoint exercises utilizing isometric and higher velocity concentric, eccentric and various stretch shortening cycle exercise needs to be examined in the future.

Adult↗
PubMed1998

Lower-extremity strength profiles in spastic cerebral palsy.

Although weakness has been identified in cerebral palsy (CP) in isolated muscle groups, the magnitude of weakness in multiple muscles and the patterns of weakness across joints have not been documented. The maximum voluntary contraction of eight muscle groups in the lower extremities of 15 children with spastic diplegia, 15 with spastic hemiplegia, and 16 age-matched peers was determined using a hand-held dynamometer. Children with spastic diplegia were shown to be weaker than age-matched peers in all muscles tested, as were the children with hemiplegia on the involved side, with strength differences also noted on the uninvolved side. Weakness was more pronounced distally in the groups with CP, and the hip flexors and ankle plantarflexors in spastic CP tended to be relatively stronger than their antagonists as compared with the strength ratios of the comparison group. In conclusion, children with spastic CP demonstrate quantifiable lower-extremity weakness and muscle imbalance across joints.

Cerebral Palsy↗
PubMed2003

Training for muscle power in older adults: effects on functional abilities.

The purpose of this study was to determine the influence of simple, progressive lower body exercise training, focusing on strength and power, on functional abilities in frail older adults. Twenty-five residents of a long-term care facility (75-94 yrs) participated in this randomized controlled trial of 10-wks duration. The exercise group (Ex, n = 18) underwent simple, progressive lower body resistance exercises, specifically aimed at improving muscle power, 3 times/wk; the control subjects (Con, n = 7) maintained their usual daily activities. Knee extensor strength and power were measured on an isokinetic dynamometer (180 degrees/s), and functional performance was assessed from a 6-m walk timed test, a 30-s chair stand, and an 8-ft up-and-go timed test, before and after the 10-wk intervention period. Significant increases were found in the Ex group for eccentric (44%) and concentric (60%) average power (p < 0.05), and improvements were seen on each functional test: the 8-foot up-and-go, chair stand, and walk time improved by 31%, 66%, and 33%, respectively (p < 0.05). No significant change occurred in the Con group. In conclusion, simple progressive exercise training, even in the 10th decade, increases muscle power and is associated with an improved performance of functional activities using the trained muscles.

Activities of Daily Living↗
PubMed1991

Motor variables correlated with the hand-to-mouth maneuver in stroke patients.

This study investigated the relationship between each of three independent variables and the completion of the hand-to-mouth maneuver in 23 hemiparetic stroke patients. The independent variables were elbow-extensor muscle tone (graded using the Modified Ashworth Scale); active elbow-flexion range-of-motion deficit measured without the influence of gravity; and elbow-flexion strength measured without the influence of gravity with a hand-held dynamometer. The hand-to-mouth maneuver was graded according to the degree of completion using a three-level ordinal scale. Spearman (rs) correlations demonstrated a significant relationship between the extent of completion of the hand-to-mouth maneuver and both the active elbow-flexion-range deficit (rs = -.853) and the elbow-flexor muscle force (rs = .829). The correlation of the maneuver with elbow-extensor muscle tone (rs = -.063) was not significant, but the relationship may have been influenced by the fact that only a minority of subjects had elevated tone, and that elevation was minimal. The result suggest that both active-movement deficits and muscle strength may be important to upper extremity function.

Arm↗
PubMed2004

Resistance training improves strength and functional capacity in persons with multiple sclerosis.

The purpose of this study was to evaluate the effect of an eight-week progressive resistance training programme on lower extremity strength, ambulatory function, fatigue and self-reported disability in multiple sclerosis (MS) patients (mean disability score 3.7 +/- 0.8). Eight MS subjects volunteered for twice weekly training sessions. During the first two weeks, subjects completed one set of 8-10 reps at 50% of maximal voluntary contraction (MVC) of knee flexion, knee extension and plantarflexion exercises. In subsequent sessions, the subjects completed one set of 10-15 repetitions at 70% of MVC. The resistance was increased by 2-5% when subjects completed 15 repetitions in consecutive sessions. Isometric strength of the quadriceps, hamstring, plantarflexor and dorsiflexor muscle groups was assessed before and after the training programme using an isokinetic dynamometer. Magnetic resonance images of the thigh were acquired before and after the exercise programme as were walking speed (25-ft), number of steps in 3 min, and self-reported fatigue and disability. Knee extension (7.4%), plantarflexion (52%) and stepping performance (8.7%) increased significantly (P < 0.05). Self-reported fatigue decreased (P < 0.05) and disability tended to decrease (P = 0.07) following the training programme. MS patients are capable of making positive adaptations to resistance training that are associated with improved ambulation and decreased fatigue.

Adult↗