Neuromechanical adjustments when walking with an aiding or hindering horizontal force
A H Dewolf1,2, Y P Ivanenko3, R M Mesquita1
1Laboratory of Biomechanics and Physiology of Locomotion, Institute of Neuroscience, Université Catholique de Louvain (UCL-FSM), Place P. de Coubertin, 1, 1348, Louvain-la-Neuve, Belgium.
European Journal of Applied Physiology
|November 9, 2019
Summary
Applying horizontal forces during walking alters the body
Area of Science:
- Biomechanics
- Neuroscience
- Human Locomotion
Background:
- Walking involves complex interplay between muscle work and energy exchange.
- Horizontal forces can disrupt the balance of positive and negative work during locomotion.
- Understanding spinal cord activity's role in adapting to external forces is crucial.
Purpose of the Study:
- Investigate how horizontal traction forces affect the body's center of mass (COM) energy exchange.
- Examine the relationship between COM dynamics and spinal motor pool activity.
- Compare neuromechanical adjustments to horizontal forces with those on slopes.
Main Methods:
- Ten subjects walked on a treadmill under varying speeds and horizontal traction forces.
- Collected kinetic, kinematic, and electromyographic data from 16 lower-limb muscles.
- Mapped spinal locomotor output to motoneuron pools.
Main Results:
- Horizontal forces shifted the timing of potential and kinetic energy exchange in the COM.
- Limb and trunk orientations aligned with the ground reaction force vector.
- Sacral and lumbar motor pools exhibited distinct activity changes based on force direction (aiding vs. hindering).
Conclusions:
- Horizontal forces induce changes in COM dynamics and spinal motor output comparable to walking on slopes.
- Findings support common principles of motor pool function in locomotion.
- Locomotor adaptations to external forces involve coordinated spinal cord activity.
