Prospective study to assess the efficacy and safety of a noninvasive electro‐muscular stimulation for improvement of muscle strength and muscle toning of the extremities
Authors: Ugonabo Nkem , Rambhia Pooja H. , You Janet , Ibrahimi Omar A. , Chapas Anne 
Published: August 2023

Objective

We sought to evaluate the safety and efficacy of an electrical muscle stimulation (EMS) device in the improvement of muscle strength and toning of the upper extremities. This device, which is FDA‐cleared as a two‐channel muscle stimulator, provides up to eight electrodes with waveforms inducing muscle stimulation. Although a prior study demonstrated it is safe and effective for use in the abdomen, this system, which has electrodes specifically designed for the extremities, has not previously been evaluated in the upper extremities.

Methods

Forty‐five subjects enrolled in the study to assess improvement in arm (i.e., bicep and tricep muscle) strength, and appearance following a protocol of treatments with this bioelectric muscle activation (BMA) device. All subjects received four 30‐min EMS treatment sessions in Arm mode—twice weekly for 2 weeks and at least 48 h apart. Follow up visits were also scheduled 30‐ and 90‐days after treatment. Strength was measured with a dynamometer device at baseline, at the final treatment session, and at the posttreatment 30‐ and 90‐day assessment. Subject satisfaction was assessed gauging overall comfort of the treatment and satisfaction including willingness to recommend to others. The changes in strength between initial treatment and final treatment, as well as 30 and 90‐day assessment were evaluated. Clinical photography at these visits was also assessed for each patient. Patients were instructed to not modify their normal exercise routine while participating in this study.

Results

All 45 subjects completed the treatment protocol. Most patients showed an improvement in muscle strength from the initial to final treatment (i.e., the fourth treatment). Specifically, the maximum bicep strength increased by a mean of 7.5 lbs (22.83%,p = 0.006), while the average increased by a mean of 8.2 lbs (25.76%,p = 0.001) during this period. Similarly, the maximum tricep strength from initial to final treatment increased by a mean of 10.0 lbs (23.16%,p = 0.000), while the average increased by a mean of 9.6 lbs (27.12%,p = 0.000). Thirty days after the last treatment, the maximum bicep strength increased by a mean of 13.3 lbs (34.13%,p = 0.001) while the average increased by a mean of 13.6 lbs (37.05%,p = 0.000) during this period. Similarly, the maximum tricep strength from initial to 30 days postfinal treatment increased by a mean of 10.9 lbs (24.37%,p = 0.000), while the average increased by a mean of 10.5 lbs (29.37%,p = 0.000). Finally, 90 days after the last treatment, the maximum bicep strength increased by a mean of 19.4 lbs (48.4%,p = 0.000), while the average increased by a mean of 17.4 lbs (46.53%,p = 0.000) during this period. Similarly, the maximum tricep strength from initial to 90 days postfinal treatment increased by a mean of 10.8 lbs (27.12%,p = 0.000), while the average increased by a mean of 10.0 lbs (30.94%,p = 0.001).

Conclusion

This device was well tolerated and resulted in increased strength measurements in the upper extremities, as assessed by a dynamometer, which were sustained at 30 and 90 days.