Effects of variation in step frequency on the coordination of the segments of the lower limbs during running. A pilot study.

Details

Supervisors

Willems, Patrick ; Catavitello, Giovanna

Faculty

Faculté des sciences de la motricité

Degree label

Master [120] en sciences de la motricité, orientation générale, à finalité approfondie

Abstract

The goal of this project is to investigate the biomechanical parameters of the lower limbs and the organisation of motor control when varying the step frequency during running at different given speeds. Six subjects ran on a treadmill at different speeds (2.22,2.78,3.06,3.89,4.72m⁄s) and at different percentages of the preferred step frequency (75%,85%,100%,115%,125%PSF). We computed different parameters, such as the general gait parameters, the range of angular motion of the thigh, shank, and foot elevation angles, as well as their phase relationships and the parameters of the planar covariation. As step frequency increases, the duration of the effective contact and aerial phases as well as the global range of angular motion and the distance between the minima of the shank and foot waveforms decreased. This implied a change in the intersegmental coordination to adapt to different environmental conditions. This adaptation could be due to the existence of a kinematic control law located at the interface between the neural commands and the environment. Kinematic synergy could thus represented a specific neuro-mechanical control of the instantaneous position of the CoM, contributing to a reduction in mechanical energy (Catavitello et al., 2018). This exploratory study provided a first perspective on the inter-limb coordination during a variation of step frequency. It identified modifications to be applied to future experiments to improve their accuracy.