The effect of external lateral stabilization on the control of mediolateral stability in walking and running
- Published
- Accepted
- Subject Areas
- Kinesiology
- Keywords
- gait stability, balance, running, walking, foot placement strategy, stepping strategy
- Copyright
- © 2019 Mahaki et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
- Cite this article
- 2019. The effect of external lateral stabilization on the control of mediolateral stability in walking and running. PeerJ Preprints 7:e27244v3 https://doi.org/10.7287/peerj.preprints.27244v3
Abstract
It is still unclear how humans control mediolateral (ML) stability in walking and even more so for running. Here, foot placement strategy as a main mechanism to control ML stability was compared between walking and running. Moreover, to verify the role of foot placement as a means to control ML stability in both modes of locomotion, this study investigated the effect of external lateral stabilization on foot placement control. Ten young adults participated in this study. Kinematic data of the trunk (T6) and feet (heels) were recorded during walking and running on a treadmill in normal and stabilized conditions. Correlation between ML trunk CoM state and subsequent ML foot placement, step width, and step width variability were assessed. Paired t-tests (either SPM1d or normal) were used to compare aforementioned parameters between normal walking and running. Two-way repeated measures ANOVAs (either SPM1d or normal) were used to test for effects of walking vs. running and of normal vs. stabilized condition. We found a stronger correlation between ML trunk CoM state and ML foot placement and significantly higher step width and step width variability in walking than in running. The correlation between ML trunk CoM state and ML foot placement, step width, and step width variability were significantly decreased by external lateral stabilization in walking and running, and this reduction was stronger in walking than in running. We conclude that ML foot placement is coordinated to ML trunk CoM state to stabilize both walking and running and this coordination is stronger in walking than in running.
Author Comment
In the previous version of our preprint, we have pooled the R^2 time series, step width and step width variability across running speeds and then we have compared these aforementioned variables between walking and running. In this version, we have selected walking at 1.25 m/s and running at 2.50 m/s, as a representative of running speeds, to test our hypotheses.
Supplemental Information
The comparsion of R2 between legs in walking and running.
(A) % of variance in ML foot placement that can be explained by ML trunk CoM state (R2) in walking and running. (B) The differences of R2 between left and right legs in walking and running.
The effect of running speeds (2.08, 2.50, and 2.92 m/s) on R2
(A) % of variance in ML foot placement that can be explained by ML trunk CoM state (R2) in running with three different speeds [2.08, 2.50, and 2.92 m/s]. (B) The effect of running speeds (2.08, 2.50, and 2.92 m/s) on R2. The shaded regions indicate standard error of R2.
Effect of running speeds on step width
Step width was significantly decreased by increasing in running speed (F (1, 2) = 9.25, p = 0.002) (Fig. S3).
Effect of running speeds on step width variability
There was no significant main effect of speed on step width variability in running (F (1, 2) = 1.48, p = 0.254) (Fig. S4).
The effect of external lateral stabilization on energy cost in walking and running
Condition effect: The effect of external lateral stabilization on energy cost in walking and running. # represents the significant differences of energy cost between normal and stabilized conditions (based on the results of Bonferroni post-hoc). Error bars represent standard deviation.