Upper Limb Muscles (upper + limb_muscle)

Distribution by Scientific Domains


Selected Abstracts


Association Between Changes in Habitual Physical Activity and Changes in Bone Density, Muscle Strength, and Functional Performance in Elderly Men and Women

JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 12 2008
Robin M. Daly PhD
OBJECTIVES: To investigate the long-term effects of habitual physical activity on changes in musculoskeletal health, functional performance, and fracture risk in elderly men and women. DESIGN: Ten-year prospective population-based study. SETTING: Malmö-Sjöbo Prospective Study, Sweden. PARTICIPANTS: Participants were 152 men and 206 women aged 50, 60, 70, and 80 who were followed for 10 years. MEASUREMENTS: Distal radius bone mineral density (BMD) (single photon absorptiometry), upper limb muscle (grip) strength, balance, gait velocity, occupational and leisure-time activity, and fractures (interview-administered questionnaire) were reassessed after 10 years. Annual changes for all measures were compared between participants with varying habitual physical activity histories at baseline and follow-up: inactive,inactive (n=202), active,inactive (n=47), inactive,active (n=49), and active,active (n=60). Data for men and women were pooled, because there were no sex-by-activity group interactions. To detect possible differences in fracture incidence between the varying habitual activity groups, participants were classified into two activity groups based on their activity classification at baseline and follow-up: inactive:less active versus active:more active. RESULTS: The annual rate of bone loss was 0.6% per year less in individuals classified as active at both time points than in those classified as inactive at both time points (P<.01). Similar results were observed for balance, but there was no effect of varying habitual activity on changes in muscle strength or gait velocity. There were also no differences in fracture incidence between individuals categorized as active:more active and those categorized as inactive:less active during the follow-up (adjusted hazard ratio=0.90, 95% confidence interval (CI)=0.42,1.90). CONCLUSION: This study showed that elderly men and women who maintained a habitually active lifestyle over 10 years had lower bone loss and retained better balance than those who remained habitually inactive. [source]


Differential age-related changes in motor unit properties between elbow flexors and extensors

ACTA PHYSIOLOGICA, Issue 1 2010
B. H. Dalton
Abstract Aim:, Healthy adult ageing of the human neuromuscular system is comprised of changes that include atrophy, weakness and slowed movements with reduced spinal motor neurone output expressed by lower motor unit discharge rates (MUDRs). The latter observation has been obtained mostly from hand and lower limb muscles. The purpose was to determine the extent to which elbow flexor and extensor contractile properties, and MUDRs in six old (83 ± 4 years) and six young (24 ± 1 years) men were affected by age, and whether any adaptations were similar for both muscle groups. Methods:, Maximal isometric voluntary contraction (MVC), voluntary activation, twitch contractile properties, force,frequency relationship and MUDRs from sub-maximal to maximal intensities were assessed in the elbow flexors and extensors. Results:, Both flexor and extensor MVCs were significantly (P < 0.05) less (,42% and ,46% respectively) in the old than in the young. Contractile speeds and the force,frequency relationship did not show any age-related differences (P > 0.05). For the elbow flexors contraction duration was ,139 ms and for the extensors it was ,127 ms for both age groups (P > 0.05). The mean MUDRs from 25% MVC to maximum were lower (,10% to ,36%) in the old than in the young (P < 0.01). These age-related differences were larger for biceps (Cohen's d = 8.25) than triceps (Cohen's d = 4.79) brachii. Conclusion:, Thus, at least for proximal upper limb muscles, mean maximal MUDR reductions with healthy adult ageing are muscle specific and not strongly related to contractile speed. [source]


Lesion of the anterior branch of axillary nerve in a patient with hereditary neuropathy with liability to pressure palsies

EUROPEAN JOURNAL OF NEUROLOGY, Issue 5 2000
S. Simonetti
We report the case of a 30-year-old woman affected by hereditary neuropathy with liability to pressure palsies (HNPP), who developed a painless left axillary neuropathy after sleeping on her left side, on a firm orthopaedic mattress, in her eighth month of pregnancy. Electromyography (EMG) showing neurogenic signs in the left anterior and middle deltoid, and normal findings in the left teres minor, posterior deltoid and other proximal upper limb muscles, demonstrated that the lesion was at the level of the axillary anterior branch. A direct compression of this branch against the surgical neck of the humerus seems the most likely pathogenic mechanism. This is the first documented description of an axillary neuropathy in HNPP. Knowledge of its possible occurrence may be important for prevention purposes. [source]


Magnetically evoked motor potentials in demyelinating and axonal polyneuropathy: a comparative study

EUROPEAN JOURNAL OF NEUROLOGY, Issue 1 2000
H. Takada
We investigated the value of magnetically evoked motor potentials (MEPs) for the differentiation of demyelinating and axonal polyneuropathies. The study population comprised 107 patients, with polyneuropathy verified by electromyography (EMG) and nerve conduction study (NCS), who had also been examined by means of MEP. MEPs were evoked by magnetic stimulation of the cortex and the spinal roots and were recorded from three upper limb muscles and two lower limb muscles bilaterally. From the EMG/NCS results 53 patients were characterized as having primary demyelination (demyelinating patients) and 54 as having axonal involvement (axonal patients). Demyelinating patients were classified as acute (acute inflammatory demyelinating polyradiculoneuropathy: AIDP ) or chronic (chronic inflammatory demyelinating polyradiculoneuropathy: CIDP ) according to the duration of illness. A series of indices were calculated from MEP results. One demyelinating patient and two axonal patients had normal MEPs. The MEPs of the demyelinating patients showed significantly longer peripheral conduction times, larger interside differences and lower amplitudes than the axonal patients. The central conduction index and the amplitudes upon cortical stimulation were significantly higher in patients with CIDP than in those with AIDP. Peripheral conduction time prolonged by more than 85% in at least one of the 10 muscles studied or a peripheral conduction index of above 9.4 were pathognomonic for demyelination . By combining all criteria 75% of the patients could be categorized as CIDP vs. AIDP in accordance with the EMG/NCS diagnosis. Likewise, 83% were categorized correctly as demyelinating versus axonal according to the EMG/NCS data. [source]


Modulation of spinal inhibitory reflex responses to cutaneous nociceptive stimuli during upper limb movement

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 3 2008
Romildo Don
Abstract In the present study we investigated the probability, latency and duration of the inhibitory component of the withdrawal reflex elicited by painful electrical stimulation of the index finger in humans. The stimulus consisted of a train of high-intensity pulses. The investigation was carried out in several upper limb muscles during isometric contractions of different strengths and during a motor sequence consisting of reaching, picking up and transporting an object. We used a new algorithm to detect and characterize the inhibitory reflex. The reflex was found in all muscles except the brachioradialis at all the isometric contraction strengths, and showed a distal-to-proximal gradient of latency and duration. Conversely, during movement the reflex probability was high (> 80%) in the anterior deltoid and triceps muscles during reaching, in the extensor carpi radialis muscle during transporting of the object, and in the first interosseous muscle during both picking up and transporting of the object. This modulation of inhibitory reflex transmission in the upper limb muscles suggests that the motor response is organized in such a way as to inhibit the overall ongoing motor task by interrupting motion during reaching and by releasing the object during transporting. This pattern of modulation appears to differ markedly from that previously reported for the excitatory component of the withdrawal reflex. Study of the nociceptive inhibitory reflexes during movement offers new and more profound insights into the functional anatomical organization of the spinal interneuronal network mediating sensory,motor integration. [source]


Botulinum Toxin, Physical and Occupational Therapy, and Neuromuscular Electrical Stimulation to Treat Spastic Upper Limb of Children With Cerebral Palsy: A Pilot Study

ARTIFICIAL ORGANS, Issue 3 2010
Gerardo Rodríguez-Reyes
Abstract Spasticity has been successfully managed with different treatment modalities or combinations. No information is available on the effectiveness or individual contribution of botulinum toxin type A (BTA) combined with physical and occupational therapy and neuromuscular electrical stimulation to treat spastic upper limb. The purpose of this study was to assess the effects of such treatment and to inform sample-size calculations for a randomized controlled trial. BTA was injected into spastic upper limb muscles of 10 children. They received 10 sessions of physical and occupational therapy followed by 10 sessions of neuromuscular electrical stimulation on the wrist extensors (antagonist muscles). Degree of spasticity using the Modified Ashworth scale, active range of motion, and manual function with the Jebsen hand test, were assessed. Meaningful improvement was observed in hand function posttreatment (P = 0.03). Median spasticity showed a reduction trend and median amplitude of wrist range of motion registered an increase; however, neither of these were significant (P > 0.05). There is evidence of a beneficial effect of the combined treatment. Adequate information has been obtained on main outcome-measurement variability for calculating sample size for a subsequent study to quantify the treatment effect precisely. [source]