Increased trunk kinetics observed during dose-specific trunk lean gait modification

Trunk modification is associated with knee abduction moment reduction in both healthy groups and individuals with knee osteoarthritis. Ambulatory-related changes in trunk kinematics have been implicated in increased trunk moment. The purpose of this study was to investigate the effect of dose-specific lateral trunk lean on trunk kinetics during ipsilateral and contralateral stance phases. Nineteen healthy participants completed 10 baseline walking trials, followed by 10 trials employing lateral trunk lean. Trunk modification magnitudes were determined based on the average baseline trunk angle. Five trials of both small and large trunk modification magnitudes were completed. Visual real-time biofeedback was projected as a line graph displaying the trunk angle during stance, and a highlighted bandwidth was designated the target range. A 1-factor repeated-measures analysis of variance or Friedman test was used to assess differences between the conditions (P < .05) in trunk dependent measures. Trunk kinetics displayed significant increases, even during modest modifications to the trunk angle. The participants experienced increased peak frontal plane trunk moment and angular impulse during ipsilateral stance. The observed increase in the peak lateral joint reaction force is suggestive of a compromised loading environment at the spine. Implementing trunk modification might result in unintended secondary changes along the kinetic chain, but further investigation is required.