Lower limb joint angle variability and dimensionality are different in stairmill climbing and treadmill walking

Abstract

The present study tested if the quadratic relationship which exists between stepping frequency and gait dynamics in walking can be generalized to stairmill climbing. To accomplish this, we investigated the joint angle dynamics and variability during continuous stairmill climbing at stepping frequencies both above and below the preferred stepping frequency (PSF). Nine subjects performed stairmill climbing at 80, 90, 100, 110 and 120% PSF and treadmill walking at preferred walking speed during which sagittal hip, knee and ankle angles were extracted. Joint angle dynamics were quantified by the largest Lyapunov exponent (LyE) and correlation dimension (CoD). Joint angle variability was estimated by the mean ensemble standard deviation (meanSD). MeanSD and CoD for all joints were significantly higher during stairmill climbing but there were no task differences in LyE. Changes in stepping frequency had only limited effect on joint angle variability and did not affect joint angle dynamics. Thus, we concluded that the quadratic relationship between stepping frequency and gait dynamics observed in walking is not present in stairmill climbing based on the investigated parameters.

Length of Time-Series Gait Data on Lyapunov Exponent for Fall Risk Detection

“…First, we only calculated the LyE starting from 120 gait cycles. This has been deemed a sufficient data length with limited gains in precision if more strides could have been included (Bruijn et al, 2009;Raffalt, Vallabhajosula, Renz, Mukherjee, & Stergiou, 2018;F. Riva et al, 2014;.…”

Joint Angle Variability Is Altered in Patients with Peripheral Artery Disease after Six Months of Exercise Intervention

“…In another study, harnesses worn during walking were reported to negatively affect ankle neuromuscular control (i.e., decreased organization of variability patterns) compared to the knee and hip [ 23 ]. In healthy young adults, joint angle variability during continuous stair mill climbing were similar across lower limb joints [ 24 ]. With known calf muscle impairments, which impact ankle contributions to walking in patients with PAD, levels of variability could differ across joints.…”