Effect of Spatially Distributed Sequential Stimulation on Fatigue in Functional Electrical Stimulation Rowing

Area of Science:

• Biomedical Engineering
• Rehabilitation Science
• Neuromuscular Electrical Stimulation

Background:

• Muscle fatigue is a primary limitation in functional electrical stimulation (FES) rehabilitation.
• Spatially distributed sequential stimulation (SDSS) has shown promise in reducing FES-induced muscle fatigue during single-joint movements.
• Investigating SDSS in a complex, multi-joint FES application like rowing is crucial for clinical translation.

Purpose of the Study:

• To evaluate the efficacy of SDSS in mitigating muscle fatigue during FES-rowing in able-bodied participants.
• To compare the fatigue-reducing capabilities of SDSS against conventional single electrode stimulation (SES) in an FES-rowing context.

Main Methods:

• Fifteen able-bodied participants performed fatiguing FES-rowing exercises targeting quadriceps and hamstring muscles.
• Two stimulation conditions were tested: single electrode stimulation (SES) and spatially distributed sequential stimulation (SDSS).
• Muscle fatigue was quantified by time to fatigue (TTF) and total trial length.

Main Results:

• SDSS significantly increased rowing trial length by an average ratio of 1.31 compared to SES.
• Time to fatigue (TTF) was significantly longer with SDSS, with a median ratio of 1.34.
• No participants experienced decreased TTF with SDSS, indicating consistent fatigue reduction.

Conclusions:

• SDSS effectively reduces muscle fatigue during FES-rowing in able-bodied individuals, extending exercise duration by approximately 30%.
• The findings suggest that SDSS can enhance the effectiveness of FES-rowing as a rehabilitative exercise for individuals with paralysis.