Effects of combined electrical muscle stimulation and blood flow restriction in individuals with spinal cord injury.

CONTEXT/OBJECTIVE: Electrical muscular stimulation (EMS) and blood flow restriction (BFR) individually show promise in spinal cord injury (SCI) rehabilitation, but their combined application in the lower extremities has not been systematically evaluated in an SCI population. This study evaluates the efficacy of combined EMS and BFR (EMS + BFR) in individuals with spinal cord injury (SCI) and characterizes acute hemodynamic responses. DESIGN: Randomized, repeated-measures experimental design. SETTING: University of Alabama Exercise Physiology Laboratory. PARTICIPANTS: Ten wheelchair users with SCI below T6. INTERVENTIONS: Three counterbalanced 20-minute conditions were applied: BFR (40% arterial occlusion pressure [AOP]), EMS, and combined EMS + BFR. OUTCOME MEASURES: Pre- and post-intervention assessments: heart rate (HR), blood pressure (BP), blood lactate ([La+]), posterior tibial artery blood flow and diameter, and vastus medialis cross-sectional area with continuous hemodynamic monitoring for autonomic dysreflexia (AD). RESULTS: No adverse events occurred. EMS + BFR produced mild, manageable hemodynamic responses with a significant main effect of interaction for systolic BP and mean arterial pressure (P < 0.05), with differences between conditions for SBP (P < 0.05). Significant main effect of time for HR (P < 0.05) was found. Baseline milliamperage required to elicit rectus femoris contraction correlated negatively with SCI location (r = -0.715, P < 0.05). CONCLUSION: No significant pressor response occurred, and there was no significant vascular or muscle swelling; the intervention was well tolerated at 40% AOP. Findings support the safety and potential clinical utility of EMS + BFR in individuals with SCI below the T6 level and provide a foundation for future investigations at higher occlusion pressures.