Abstract WP321: Somatosensory Stimulation Combined with Moderate Intensity Therapeutic Exercise Significantly Improves Motor Function in Chronic Stroke Survivors

Abstract

Background: Somatosensory stimulation using electrical microcurrents (MSOMA) has proven efficacious for treatment of pain and tissue healing however little is known about its use to augment hemiparetic muscle response to therapeutic exercise. The study aimed to investigate functional upper limb control in chronic stroke survivors in response to a standardized combination of MSOMA and moderate intensity therapeutic exercise. Methods: 18 chronic stroke survivors (M/F = 12 / 6), age 59.68 +/- 18.67 years were assigned to two treatment groups with (n= 10), and without MSOMA (n = 8) in a university outpatient physical therapy clinic. Chronicity of impairment was 3.75 +/- 2.23 years. All groups participated in therapeutic exercise using “forced-use” of impaired limbs including total body reciprocal training and robot-assisted limb activities for 12 weeks. The MSOMA group received electrotherapy during clinic sessions and used the units during a standardized Home Exercise Program prescribed for both treatment groups. All patients were assessed at Baseline, 6-weeks and 12-weeks. Variables: Outcomes included Motor Activity Log-28 (MAL), Stroke Impact Scale (SIS), Box & Blocks Test (BBT), grip strength (GRIP) and surface EMG activity in both upper extremities during a “Push Task” simulating the sit-to-stand transfer. EMG outcomes included mean muscle activity (MMA), and relative intra- and inter-limb muscle activity. Data Analysis: Statistical data analysis included descriptive statistics and repeated measures ANCOVA with Eta-squared values (η2). Games-Howell Post Hoc analysis with a Bonferroni correction was used at an alpha level of 0.05. Results: Results indicate a significant group difference with a low to moderate effect size for BBT (p = 0.086, η2 = 0.041), GRIP (p = 0.010, η2 = 0.384) and MMA values at 12-weeks with a significant Group x Time interaction effect for MAL (p = 0.040, η2 = 0.238) and SIS scores (p = 0.027, η2 = 0.344). Conclusions: Results indicate that standardized MSOMA combined with moderate intensity therapeutic exercise is tolerated well by chronic stroke survivors and can significantly improve fine and gross motor function in impaired upper limbs. Further investigation is warranted to explore dosage-specific responses in patients.