Quantifying coordinative patterns in steady‐state running: The impact of footwear and foot strike on joint coupling variability.

In this study, we aimed to compare and contrast the intralimb coordinative patterns of habitual forefoot strikers (FFS) and rearfoot strikers (RFS) during steady‐state running across three different shoe types: minimalist, neutral and cushioned shoes. To describe these coordinative patterns, we implemented the concept of the 'preferred movement path' which represents the movement path that runners naturally select in response to their physical capacity and external environment. We quantified cycle‐to‐cycle consistency (ACC) and within‐trial variance in coordination patterns (SoV) using joint angle data from the ankle and knee for ankle‐knee coupling and from the knee and hip for knee‐hip coupling. Additionally, we calculated the measure of shape difference in joint coupling as the sum of squared distances (SSD) between/within conditions and groups. The percentage of runners who displayed shape differences below certain SSD thresholds was also evaluated. Our findings revealed no significant group or shoe type effect on any of the variability measures (ACC: p = 0.460 for ankle‐knee and p = 0.832 for knee‐hip; SoV: p = 0.345 for ankle‐knee and p = 0.755 for knee‐hip). However, there was a significant (p < 0.001) shape difference observed between the most extreme shoe conditions. Despite this, when runners switched shoes, 70%–90% of them maintained their original coordinative pattern across both joint couplings, indicating a strong adherence to their preferred movement path. This suggests that while shoe type can influence the shape of the coordinative pattern, the inherent movement tendencies of the runners remain largely consistent. Highlights: The study found no differences in the cyclogram variability between habitual foot strike classification groups when wearing different shoes.The largest number of different movement responses was present at the ankle‐knee coupling.A significantly greater proportion of participants changed their ankle‐knee and knee‐hip coordinative patterns between the High versus Low Minimal Index (MI) conditions compared to the other shoe comparisons.No differences were found between the groups in terms of cyclogram variability. [ABSTRACT FROM AUTHOR]