Neuromuscular Electrical Stimulation Use in Transtibial Amputations

Individuals with amputations experience an invasive surgery compromising the residual limb resulting in detriments such as a decrease in muscle strength, muscle atrophy, pain and gait impairments. Neuromuscular Electrical Stimulation (NMES) has been shown to improve the strength and volume of the quadriceps muscles in individuals who have experienced a total knee arthroplasty, osteoarthritis of the knee, anterior cruciate ligament repair and in individuals who suffer from a chronic illness. NMES has also been shown to decrease pain in conditions such as knee osteoarthritis, chronic back pain, and total knee arthroplasty. We proposed a novel idea to apply NMES to individuals with amputation to see if we can achieve the same results. The purpose of this study was to demonstrate the efficacy of NMES for individuals with a transtibial amputation. We aimed to demonstrate that when compared to a control group, individuals who received three months of NMES intervention will show greater knee extension strength, increased volume of the residual limb, decreased chronic and phantom pain and improved gait relative to the baseline measures. We also evaluated the feasibility of this intervention and determined effect sizes to power a larger study. Twenty unilateral transtibial participants who were greater than one-year post amputation were recruited and randomized into two groups. The study consisted of a baseline visit and four follow up visits. Changes in outcomes were examined between baseline and 12 weeks using a Mann-Whitney U test and box and scatterplots. Fifteen subjects completed the study. The data showed no statistical significant changes in all the outcomes except for a significant decrease in residual limb pain at 12 weeks (p=0.03). Clinically significant changes in various outcome measures were found for some individual participants. Although the study findings were inconclusive participants felt that their strength and residual limb shape improved with the NMES intervention and that the NMES was very easy to use. This pilot study demonstrated feasibility and excellent compliance with an at-home NMES intervention. A future study involving refined measurement techniques and testing with a larger cohort of transtibial amputees is warranted