Leg joint power output during progressive resistance FES-LCE cycling in SCI subjects: developing an index of fatigue

This study investigates the biomechanics of the hip, knee, and ankle during progressive resistance cycling to detect muscle fatigue in individuals with spinal cord injuries (SCI). The goal is to determine if knee power output can indicate fatigue and assess cycling performance. The study recorded kinematic data and pedal forces during cycling at increasing resistance levels. Ankle, knee, and hip power outputs were calculated, along with ergometer cadence and muscle stimulation intensity. The results showed that ankle and knee power outputs decreased, while hip power output increased with resistance. Cadence, stimulation intensity, and resultant pedal force were significant predictors of knee power output. A fatigue index was developed based on these predictors to quantify knee joint power capacity.

• 1
  Ankle and knee power outputs decreased with increasing resistance, while hip power output increased.
• 2
  Cadence, stimulation intensity, and resultant pedal force were significant predictors of knee power output.
• 3
  An index of fatigue was developed to quantify the power capacity of the knee joint with respect to a baseline power level.