Motor unit discharge behavior in older adults during maximal-effort contractions
| Autor: | Steve Sison, Gary Kamen, C. C.D. Du, Carolynn Patten |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
Dorsum
Adult medicine.medical_specialty Aging Time Factors Physiology Action Potentials Isometric exercise Discharge rate Physical medicine and rehabilitation Physiology (medical) Motor unit potentials medicine Humans Young adult Aged Motor Neurons business.industry Age Factors Motor neuron Motor unit Electrophysiology medicine.anatomical_structure Physical therapy business Muscle Contraction |
| Zdroj: | Journal of applied physiology (Bethesda, Md. : 1985). 79(6) |
| ISSN: | 8750-7587 |
| Popis: | A reduction in maximal force production is a common observation in older individuals. In an effort to determine whether aging is accompanied by reductions in central motoneuron drive limiting motor performance, motor unit discharge records were obtained from seven young (21–33 yr) and seven older (> 67 yr) adults. Informed consent was obtained from all subjects. The task required the subject to perform a maximal abduction of the second digit under isometric conditions. Motor unit potentials in the first dorsal interosseous were monitored by using a selective four-wire needle electrode and identified off-line with the aid of a Dantec electromyograph. The maximal discharge rate in the older adults (31.1 impulses/s) was significantly smaller (P < 0.05) than that in the younger subjects (50.9 impulses/s). These findings suggest that reductions in maximal force capability in older adults are partially due to an impaired ability to fully drive the surviving motor units. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|