Multi muscle neuromuscular electrical simulation of the lower limbs: Effect on intra and inter limb motor pools

Society for Neuroscience Chicago 2015 Spinal Cord Injury I SCI and Plasticity Support: NJCSCR14

Multi muscle neuromuscular electrical simulation of the lower limbs: Effect on intra and inter limb motor pools

Abstract: Acute spinal cord injury often leads to rapid muscle atrophy in the paralyzed limbs. Recently, we have shown that an intense novel form of standardized multi-muscle neuromuscular electrical stimulation (NMES) combined with dynamic standing retraining tasks may potentially restore muscle structure and function after sub acute to chronic, motor-complete SCI. Specifically, we have presented data for a large number of standardized repetitive task specific training sessions of multi-muscle NMES of the lower limbs combined with mechanical loading to demonstrate an increase in bilateral muscle volume in conjunction with a significant increase in flexor and extensor muscle activation amplitude during continuous stepping. Albeit the phasic coordination of the flexor and extensor muscle activation pools were inappropriate for stepping. However, very little is known about the effect of multi-muscle NMES during mechanical loading on the motor pools of the ipsilateral and contralateral flexors or extensors during stimulation. We will present data on a series of experiments to illustrate intra and inter limb neuromuscular response for several individuals who have cervical motor complete SCI as well as several able bodied controls undergoing a standardized NMES and mechanical loading testing protocol. These data show that during repeated bouts of a ramping stimulation protocol to the lower limb extensor muscles while standing there was concomitant recorded stimulation to multiple muscle sites of contralateral limb. For both motor complete SCI and able bodied controls, there were significant increases in muscle activation amplitudes for both ipsilateral and contralateral extensors during NMES ramping protocol. Moreover these data reflected changes in spatial and temporal characteristics of the standardized repeated bouts of NMES train as well as the changes in the ipsilateral and contralateral loading forces and net center of pressure. We propose that our experiments potentially demonstrate that for the intact human spinal cord and for the motor complete individual, single muscle stimulation and multi-muscle stimulation may play a significant role in intra/inter limb neural circuitry changes.

Disclosures: G.F. Forrest: None. M. Bugrahan Bayram: None. R. Pilkar: None. A. Ramanujam: None. M. Mitchell: None. E. Garbarini: None.

Authors: *G. F. FORREST1, M. BUGRAHAN BAYRAM2, R. PILKAR2, A. RAMANUJAM2, M. MITCHELL2, E. GARBARINI2; 1Kessler Fndn. Res. Ctr., West Orange, NJ; 2Human Performance and Engin. Lab., Kessler Fndn., West Orange, NJ