Peak Vertical Ground Reaction Force Modifies Gait Biomechanics Bilaterally Following ACL Reconstruction: A Randomized...

Area of Science:

• Biomechanics
• Orthopedics
• Rehabilitation Science

Background:

• Vertical ground reaction force (vGRF) is a key factor in gait biomechanics.
• Aberrant gait patterns are common in individuals after anterior cruciate ligament reconstruction (ACLR).
• Targeting vGRF may offer a novel approach to improve gait post-ACLR.

Purpose of the Study:

• To investigate the acute effects of different visual feedback conditions on vGRF and associated gait biomechanics.
• To compare outcomes between limbs and across four conditions (HIGH, LOW, SYMMETRICAL vGRF feedback, and control) in individuals 6-12 months post-ACLR.

Main Methods:

• A randomized, cross-over mechanistic trial was conducted.
• Participants (6-12 months post-ACLR) walked 3000 steps on a dual-belt treadmill under four conditions.
• Mixed effects linear models analyzed differences in vGRF, peak knee flexion angle (KFA), KFA range-of-motion (ROM), peak knee extension moment (KEM), and peak knee abduction moment (KAM).

Main Results:

• The HIGH vGRF feedback condition significantly increased first peak vGRF, peak KFA, KFA ROM, and peak KEM compared to the control.
• The LOW vGRF feedback condition led to decreased first peak vGRF and KFA ROM, but increased peak KFA and KEM.
• No significant changes were observed in the SYMMETRICAL vGRF feedback condition compared to the control.

Conclusions:

• vGRF biofeedback, particularly the HIGH condition, can acutely improve sagittal plane kinematics and kinetics in individuals post-ACLR.
• vGRF is a viable target for gait modification strategies.
• Further research is needed to evaluate the long-term effects of vGRF-driven feedback treatments.