Estimating Gait Stability: Asymmetrical Loading Effects Measured Using Margin of Stability and Local Dynamic Stability

ABSTRACT

Changes to intersegmental locomotor control patterns may affect body stability. Our study aimed to (a) characterize upper body dynamic stability in response to the unilateral addition of mass to the lower extremity and (b) evaluate the efficacy of 2 different stability measures commonly used in the literature to detect resulting symmetrical step pattern modifications across the weighted segments (spatial) and between epochs of the gait cycle (temporal). Young adults walked on a treadmill while unloaded or with weights applied unilaterally to their foot, shank, or thigh. Both margin of stability and local dynamic stability (LDS) estimates detected similar trends of distal segment weighting resulting in more unstable upper body movement compared to proximal weighting; however only LDS detected anteroposterior changes in upper body stability over time.

Keywords:

• adaptation
• asymmetrical leg loading
• gait
• local dynamic stability
• margin of stability
• neuromuscular control

ACKNOWLEDGMENTS

The authors would like to thank Megan Kamphuis and Pratham Singh for their contributions with data acquisition and analyses. All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional research board and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

Funding

This project was funded by grants from the Natural Sciences and Engineering Research Council (NSERC) of Canada awarded to LAV and SHMB.