Effect of load during electrical stimulation training in spinal cord injury

Abstract

Electrical stimulation training is known to alter skeletal muscle characteristics after a spinal cord injury, but the effect of load on optimizing the training protocol has not been fully investigated. This study investigated two electrical-stimulation training regimes with different loads on intramuscular parameters of the paralyzed lower limbs. Six paraplegic individuals with a spinal cord injury underwent electrical stimulation training (45 min daily for 3 days per week for 10 weeks). One leg was trained statically with load, and the contralateral leg was trained dynamically with minimal load. Isometric force assessed with 35-HZ stimuli increased significantly in both legs from baseline, with the static-trained leg also being significantly higher than the dynamic-trained leg. The vastus lateralis muscle of the statically trained leg showed a significant increase in type I fibers, fiber cross-sectional area, capillary-to-fiber ratio, and citrate synthase activity when compared to both baseline and the dynamically trained leg. Relative oxygenation of the vastus lateralis muscle as determined by near infrared spectroscopy was also significantly greater after static training. This study indicates that the load that is applied to paralyzed muscle during an electrical stimulation training program is an important factor in determining the amount of muscle adaptation that can be achieved.

Muscle and bone plasticity after spinal cord injury: Review of adaptations to disuse and to electrical muscle stimulation

“…Muscles trained with low loads displayed only small increases [36] or no change [30,35] in cross-sectional area. Most tellingly, quadriceps muscles trained with high load experienced significantly greater improvements in force, type 1 fiber composition, fiber cross-sectional area, capillary-to-fiber ratio, relative oxygenation, and citrate synthase activity than muscles trained with minimal load [49]. Thus, paralyzed muscle continues to adapt according to principles of physical stress [50], in a manner reminiscent of neurologically intact muscle.…”

Electrical Stimulation During Gait Promotes Increase of Muscle Cross-sectional Area in Quadriplegics: A Preliminary Study

“…Producing muscle contractions in paralyzed muscles through NMES of intact peripheral motoneurons [22] can promote muscle hypertrophy [9,11], muscle endurance increase, and histochemical changes [21]. The positive muscle alterations provided by NMES also can benefit the oxygen consumption [5,10,12,17] and bone mass of individuals with spinal cord injury [2,6,19].…”

Controle LQR Aplicado ao Movimento da Articulação do Joelho de Pacientes Paraplégicos

“…A eletroestimulação utilizada adequadamente pode auxiliar na recuperação de um paciente, atuando, por exemplo, no sistema circulatório, aumentando a circulação de sangue no membro paralisado e contendo a atrofia muscular (Crameri et al, 2004).…”