Cognition and skill learning in single leg loading: the role of augmented visual feedback on motor control performance

Externally provided visual feedback is often delivered to an individual during an activity to provide information on ‘performance’. These modes of feedback delivery are termed ‘augmented’ as it is externally provided to the user, often through wearables, practitioners, or coaches. However, no studies have examined the effect of on-screen visual feedback in conjunction with both within-session single-leg squat ‘performance’ and musculoskeletal profiling tools. This study aimed to investigate the effect of concurrent and terminal visual feedback on Qualitative Analysis of Single Leg Loading (QASLS) score. The alternative hypothesis (H1) was that there was at least ‘strong’ evidence (BF10 ≥ 10) for an effect on QASLS score. Participants (N = 17) completed two single-leg squat trials 1 week apart. Trials were held in a randomised order with participants completing three sets of three repetitions on both limbs. No performance information was provided in the control condition. The experimental condition included administering visual feedback (identification of ‘movement strategies’) using two 84” PhilipsTM monitors placed directly in front of participants. Data were analysed using a two-tailed Bayesian paired sample t-test with a Cauchy prior. Mean (SD) QASLS score for the no feedback and feedback conditions were 3.54 (0.78) and 3.02 (0.83), respectively. The effect size (Cohen’s dz; 95% HDI) for the mean difference was 1.42 (0.72 – 2.16). The BF10 was 2340 providing ‘extreme’ evidence for the alternative hypothesis. The data provide ‘extreme’ evidence for a ‘very large’ reduction in QASLS score when using feedback. Consequently, demonstrating within-session motor adaptation in response to altered afferent information, suggesting that the incorporation of visual feedback can enhance short-term motor control performance. Additionally, practitioners could make more informed decisions regarding QASLS results by distinguishing between implicit and explicit task-based compensations. This may reduce the counter-productive nature of unsuitable programs, potentially benefiting the user’s long-term performance through appropriate feedback administration. However, the wide credible interval for the mean difference means there is uncertainty in this estimate. As such, the results should be interpreted with caution as the small sample can inflate the effect size, whereby, the ‘true’ effect of visual feedback on QASLS would require additional studies with larger samples.