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Objective: To investigate the feasibility of neuromuscular electrical stimulation cycling modified to suit persons with advanced multiple sclerosis. Subjects: Eight women with secondary progressive multiple sclerosis. Methods: Subjects participated in an 18-session (40 min) neuromuscular electrical stimulation cycling program. A pedaling cadence of 10 rev•min-1 was employed and stimulation intensity was not modulated to control cadence, but increased gradually throughout each session. The outcomes included the stimulation intensity tolerated, thigh circumference changes, and power output and cardiorespiratory response during cycling. Participants were interviewed about perceived benefits of the treatment including changes in transfer ability. Results: Seven participants (Expanded Disability Status Scale 6.5–8.5) (mean 7.4 (standard deviation 0.7)) completed the training program over an average of 10 weeks. Greater stimulation intensities were tolerated than previously reported for persons with multiple sclerosis. Increases were found in thigh volume. Perceived benefits included improvements in transfer ability, leg circulation, spasticity and strength. Conclusion: Modifying neuromuscular electrical stimulation cycling allowed persons with advanced multiple sclerosis to tolerate greater stimulation intensities and exercise their muscles more intensely than previous studies. The benefits reported, which were solely due to neuromuscular electrical stimulation cycling, demonstrate that persons with preserved sensation and muscle paralysis/paresis might benefit from neuromuscular electrical stimulation exercise when it is adjusted appropriately.

This study analysed external power output and physiologic responses in 5 individuals with paraplegia during 40 minutes of electrical stimulation leg cycle exercise. Cycling was performed on a motor-driven isokinetic ergometer that enabled precise determinations of power output. Electrical stimulation was increased to 120-140 mA within the first 5 minutes and remained constant thereafter. Power output increased to 10.7 +/- 3.0 W after 2 minutes, dropped to 5.3 +/- 1.8 W after 6 minutes and subsequently recovered to 8.2 +/- 2.2 and 6.1 +/- 2.3 W after 19.5 and 40 minutes, respectively. Oxygen consumption increased to 0.47 +/- 0.09 l/min after 6 minutes and declined during the second half of the exercise bout. Gross mechanical efficiency after 19.5 minutes was elevated compared with the value after 6 minutes. Heart rate was significantly increased at the end of the trial. The time-dependent variability of power output and physiological responses question the concept of steady state for this form of exercise.

Objective: This study investigated the effect of pedal cadence upon torque production, power output and muscle fatigue rates during functional electrical stimulation evoked cycling in spinal cord injured individuals. Subjects: All subjects had complete thoracic spinal cord injuries T4–T9 (ASIA A) and had been functional electrical stimulation training regularly for at least 6 months. Methods: One trial (n = 8) examined a low vs high pedal rate (20 and 50 rev min 1 ) upon isolated muscle fatigue over 5 minutes. A second trial (n = 9) investigated the effect of cadence (15 vs 50 rev min 1 ) upon performance during 35-minutes of functional electrical stimulation evoked cycling. Results: Peak torque produced by left quadriceps decayed significantly faster at the higher pedal cadence, indicating a higher rate of muscle fatigue. Functional electrical stimulation cycling over 35 minutes also revealed that peak and average torques were significantly greater at the lower cadence. From 15 minutes onwards, power output was significantly higher at 50 rev min 1 FES-cycling, compared with 15 rev min 1 . Conclusion: The higher muscle forces observed during low cadence functional electrical stimulation cycling should offer improvements over traditional pedalling velocities for training leg strength in individuals with spinal cord injury.