Does Neuromuscular Electrical Stimulation Therapy Increase Voluntary Muscle Strength After Spinal Cord Injury? A Systematic Review

Abstract

Physical therapists frequently use neuromuscular electrical stimulation (NMES) therapy in an effort to increase the voluntary strength of partially paralyzed muscles in people with spinal cord injury (SCI), but it is not clear whether this treatment is effective. To determine the effectiveness of NMES for increasing voluntary strength in the partially paralyzed muscles of people with SCI. A systematic review of scientific literature was conducted in MEDLINE, CINAHL, PEDro, ScienceDirect, and Embase. Inclusion criteria were randomized controlled trials and controlled trials that compared NMES aimed at increasing strength in partially paralyzed muscles versus placebo/nothing or versus a nonstrengthening intervention or versus any other type of strengthening intervention in adults with SCI. Five studies were included. Two studies found an increase in strength measured by peak force and manual muscle force test after an NMES protocol. One study found a between-group difference in favor of the NMES associated with progressive resistance training, and the other study showed an increase in the number of muscles improved by at least 1 degree of strength after NMES in combination with a cycle ergometer. The other 3 studies made several comparisons and found no differences between groups that received NMES and the controls. There is some suggestion that NMES increases voluntary strength in partially paralyzed muscle following SCI. However, there is no strong evidence to affirm the superiority of NMES over other treatment strategies used to gain strength in partially paralyzed muscles after SCI. These findings need replicating in large high-quality randomized controlled trials.

Effects of Neuromuscular Electrical Stimulation Combined with Exercises versus an Exercise Program on the Physical Characteristics and Functions of the Elderly: A Randomized Controlled Trial

“…Several researchers have reported on the NMES being an alternative, low-cost, efficient, and less painful approach [ 3 , 4 , 5 , 6 ]. Thus, the application of NMES during rehabilitation would improve exercise tolerance [ 5 ], effectively slowing muscle wasting during denervation or immobilization, increasing voluntary strength in partially paralyzed muscle [ 7 , 8 ], preventing skeletal muscle weakness [ 9 ], and optimizing the recovery of muscle strength [ 4 ].…”

Reduction in post-spinal cord injury spasticity by combination of peripheral nerve grafting and acidic fibroblast growth factor infusion in monkeys

“… 51 In a recent pilot study, resistance training at maximal intensity also improved walking and balance and tended to decrease the modified Ashworth score. 52 However, we found that physical therapy, including general stretching and treadmill training, was not sufficient for preventing spasticity after SCI in monkeys.…”

Omitting TMS component from paired associative stimulation with high-frequency PNS: A case series of tetraplegic patients

“…Peripheral electrical stimulation in spinal cord injury has been studied more in the form of neuromuscular electrical stimulation (NMES), or more specifically, functional electrical stimulation (FES) which activates muscles performing certain functions. In SCI and tetraplegia, there is preliminary evidence that FES can reduce disability ( Patil et al, 2014 ) and improve muscle strength ( de Freitas et al, 2018 ). However, PNS is different from NMES/FES, as PNS is set to stimulate the peripheral nerves and results in a mass activation of innervated muscles, as well as antidromic neuronal impulses from stimulation site, which in our protocol is set to reach the spinal cord and corticomotoneuronal synapse ( Shulga et al, 2016a , Rodionov et al, 2020 , Rodionov et al, 2019 , Tolmacheva et al, 2019a , Tolmacheva et al, 2017 ).…”

“…First, PNS results in repetitive muscle contraction, which may lead to muscle force improvement in injured patient. In studies of NMES stimulation for SCI patients there has been improvement in stimulated muscle strength ( de Freitas et al, 2018 ). Even though the settings in PNS are different from NMES, PNS could also improve MMT values through the same mechanism as NMES, activating the muscles innervated by the stimulated nerve.…”