Increasing muscle mass in spinal cord injured persons with a functional electrical stimulation exercise program

Area of Science:

• Neurology
• Rehabilitation Medicine
• Exercise Physiology

Background:

• Spinal cord injury (SCI) often leads to significant muscle atrophy and altered body composition in the lower extremities.
• Restoring muscle mass and function is crucial for improving quality of life and potential mobility in individuals with SCI.

Purpose of the Study:

• To quantify muscle mass changes in the lower extremities induced by functional electrical stimulation (FES)-induced cycling in individuals with SCI.
• To determine the distribution of muscle mass changes within the thigh muscles.
• To assess changes in body composition, specifically the ratio of muscle to adipose tissue.

Main Methods:

• A 3-phase FES-induced ergometry program was implemented for 13 men with SCI.
• Computed tomography (CT) scans assessed muscle cross-sectional area and tissue composition at baseline and follow-up.
• The program involved quadriceps strengthening, sequential muscle stimulation, and 30-minute cycling sessions.

Main Results:

• Significant increases in cross-sectional areas were observed in rectus femoris (31%), sartorius (22%), adductor magnus-hamstrings (26%), vastus lateralis (39%), and vastus medialis-intermedius (31%).
• Muscle to adipose tissue ratio increased significantly in thighs and calves.
• No correlation was found between the total number of sessions and the degree of muscle hypertrophy.

Conclusions:

• Regular FES-induced lower extremity cycling (average 2.3 sessions/week) effectively increases lower extremity muscle cross-sectional area and improves muscle-to-adipose tissue ratio in individuals with SCI.
• The observed muscle hypertrophy distribution was influenced by the proximity of muscles to the stimulating electrodes.