Causal relationship between spatiotemporal parameters of walking and the locomotor rehabilitation index in healthy people.

Background: Walking speed is a functional vital sign affecting mechanical parameters individually. Further, there is a tendency for pathological gait to occur at slower speeds, which does not always allow for an adequate comparison with normal gait. Therefore, recognizing the influence of spatiotemporal adjustments on healthy gait can broaden our understanding of the applicability of gait quality markers.

Research Question: This study aimed to identify the causal relationship between the stride length-frequency walking ratio index (R_SL/SF) at the self-selected walking speed (SSWS) and optimal walking speed (OWS) and the locomotor rehabilitation index (LRI) in healthy adults.

Materials And Methods: Healthy adults (n = 68) of both sexes aged 20-59 years were included in this study. The SSWS was determined using a 30-m walkway. The OWS and LRI were predicted by equations proposed in the literature. The volunteers walked on the treadmill at speeds corresponding to the OWS and SSWS in two bouts of 60 s each, with a break in between. The spatiotemporal parameters were recorded using a high-speed digital video camera, digitalized, and mathematically processed. Multiple linear regression was applied using the forced regression method.

Results: Significant correlations were found between the LRI and R_SL/SF at the SSWS (R = 0.397; p < 0.001) and OWS (R = 0.266; p = 0.014). The regression model showed that 16 % of the variability in the LRI was attributable to the R_SL/SF variability at the SSWS. The average and 95 % confidence interval LRI were 94.7 % (91.6 %-97.8 %).

Conclusion: The LRI average is around 95 % for healthy and young adults and the R_SL/SF explained just 16 % of the variance in LRI.