An Adaptive Pedaling Assistive Device for Asymmetric Torque Assistant in Cycling

Area of Science:

• Biomechanics
• Rehabilitation Engineering
• Neuromuscular Physiology

Background:

• Dynamic loading impacts lower limb joint rehabilitation, but effective exercise programs remain debated.
• Current cycling ergometers provide symmetrical loading, which may not suit patients with asymmetric limb function, such as those with Parkinson's or Multiple Sclerosis.
• Assessing mechano-physiological responses during lower limb rehabilitation requires precise mechanical loading.

Purpose of the Study:

• To develop and validate a novel cycling ergometer capable of applying asymmetric loads to lower limbs.
• To investigate the effects of asymmetric loading on pedaling mechanics and muscle activity during cycling.
• To assess the potential of this device for targeted rehabilitation in patients with asymmetric lower limb function.

Main Methods:

• Development of an instrumented cycling ergometer with force sensors and crank position sensing.
• Implementation of an electric motor to apply asymmetric assistive torque to a target leg.
• Human testing involving cycling tasks at varying intensities to evaluate device performance.

Main Results:

• The developed ergometer successfully applied asymmetric assistive torque, reducing target leg pedaling force by 19% to 40% across different exercise intensities.
• This reduction in pedaling force led to a statistically significant decrease (p < 0.001) in the muscle activity of the target leg.
• Muscle activity in the non-target leg remained unaffected, demonstrating the device's targeted effect.

Conclusions:

• The novel cycling ergometer effectively delivers asymmetric lower limb loading.
• This technology holds promise for enhancing exercise interventions and improving rehabilitation outcomes for individuals with asymmetric lower limb impairments.