Background

Running retraining with the use of biofeedback on an impact measure has been executed or evaluated in the biomechanics laboratory. Here, the execution and evaluation of feedback-driven retraining are taken out of the laboratory.

Purpose

To determine whether biofeedback can reduce the peak tibial acceleration with or without affecting the running cadence in a 3-week retraining protocol.

Study Design

Quasi-randomized controlled trial.

Methods

Twenty runners with high peak tibial acceleration were allocated to either the retraining (n=10, 32.1±7.8 yrs., 10.9±2.8 g) or control groups (n=10, 39.1±10.4 yrs., 13.0±3.9 g). They performed six running sessions in an athletic training environment. A body-worn system collected axial tibial acceleration and provided real-time feedback. The retraining group received music-based biofeedback in a faded feedback scheme. Pink noise was superimposed on tempo-synchronized music when the peak tibial acceleration was ≥70% of the runner’s baseline. The control group received tempo-synchronized music, which acted as a placebo for blinding purposes. Speed feedback was provided to obtain a stable running speed of ~2.9 m·s-1. Peak tibial acceleration and running cadence were evaluated.

Results

A significant group by feedback interaction effect was detected for peak tibial acceleration. The experimental group had a decrease in peak tibial acceleration by 25.5% (mean: 10.9±2.8 g versus 8.1±3.9 g, p=0.008, d=1.08, mean difference = 2.77 [0.94, 4.61]) without changing the running cadence. The control group had no change in peak tibial acceleration nor in running cadence.

Conclusion

The retraining protocol was effective at reducing the peak tibial acceleration in high-impact runners by reacting to music-based biofeedback that was provided in real-time per wearable technology in a training environment. This reduction magnitude may have meaningful influences on injury risk.