Electromyographic activity,H-reflex modulation and corticospinal input to forearm motoneurones during active and passive rhythmic movements |
| |
| Institution: | 1. Department of Human Movement Studies, Perception and Motor Systems Laboratory, The University of Queensland, Brisbane, Queensland 4072, Australia;2. School of Kinesiology, Simon Fraser University, Burnaby, BC, Canada;1. College of Teacher Education, Xingtai University, Xingtai 054001, China;2. College of Physics Science and Information Engineering, Hebei Normal University, Shijiazhuang 050016, China;3. Department of physics, Shijiazhuang College, Shijiazhuang 050001, China;1. Department of Physical Therapy, Loma Linda University, Loma Linda, CA, USA;2. School of Allied Health Professions, Loma Linda University, Loma Linda, CA, USA;3. Physical medicine and Rehabilitation, Pain management, Hoag Hospital, Newport Beach, CA, USA;4. Department of Physical Therapy, King Saud University, Riyadh, Saudi Arabia;5. Department of Physical Therapy, Gachon University, Incheon, Korea;1. Department of Burn Surgery, Changhai Hospital, Second Military Medical University, Shanghai, P. R. China;2. Department of General Surgery, 309th Hospital of PLA, Beijing, P.R. China;3. Department of Respiratory Medicine, Changzheng Hospital, Second Military Medical University, Shanghai, P. R. China;1. School of Health and Kinesiology, College of Education, University of Nebraska at Omaha, 6001 Dodge Street, Omaha, NE 68182, United States;2. Department of Child, Youth, and Family Studies, College of Education and Human Sciences, University of Nebraska at Lincoln, 1400 R St., Lincoln, NE 68588, United States;3. Department of Biomechanics, College of Education, 6160 University Drive, Omaha, NE 68182, United States |
| |
| Abstract: | Four subjects produced coordinated movements, consisting of flexion and extension of the wrist in ipsilateral (right wrist only), contralateral (left wrist only), inphase (both wrists in flexion or both in extension) and antiphase (one wrist in flexion, the other in extension) conditions. Electromyographic (EMG) activity was recorded from right wrist flexor and extensor muscles. In one session, transcranial magnetic stimuli (TMS) of the left motor cortex, around threshold intensity, evoked short-latency responses in the right wrist extensors and flexors. In another session, the median nerve at the cubital fossa was stimulated to elicit an H-reflex in the right flexor carpi radialis (rFCR). A movement cycle was divided into 8 segments. In total, 10 identical stimuli were delivered during each segment in each condition, at two movement frequencies. The magnitude of the EMG reponses to TMS was modulated markedly during movements made in the ipsilateral condition, and in both bimanual conditions. EMG activity was greater, and motor-evoked potentials (MEPs) were larger in the antiphase condition than in the inphase condition. When the amplitudes of the MEPs were normalised with respect to background EMG, no significant differences between the bimanual conditions were obtained. For H-reflexes, significant differences between the two bimanual conditions were observed, suggesting differences in levels of excitability of the Ia afferent pathway. These differences were attributed to segmental input associated with changes in muscle length arising from limb movement, and upon descending input to the spinal cord, possibly mediated by Renshaw cell inhibition. During rhythmic passive movement of the right limb, H-reflexes were inhibited and MEPs potentiated in a cyclic fashion. Passive movement of the contralateral left limb resulted in inhibition of both responses.PsycINFO classification: 2330; 2530; 2540 |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
