Lower extremity sagittal joint moment production during split-belt treadmill walking

Abstract

The split-belt treadmill (SBT) has recently been used to rehabilitate locomotor asymmetries in clinical populations. However, the joint mechanics produced while walking on a SBT are not well-understood. The purpose of this study was to investigate the lower extremity sagittal joint moments produced by each limb during SBT walking and provide insight as to how these joint moment patterns may be useful in rehabilitating unilateral gait deficits. Thirteen healthy young volunteers walked on the SBT with the belts tied and in a “SPLIT” session in which one belt moved twice as fast as the other. Sagittal lower extremity joint moment and ground reaction force impulses were then calculated over the braking and propulsive phases of the gait cycle. Paired t-tests were performed to analyze magnitude differences between conditions (i.e. the fast and slow limbs during SPLIT vs. the same limb during tied-belt walking) and between the fast and slow limbs during SPLIT. During the SPLIT session, the fast limb produced higher ground reaction force and ankle moment impulses during the propulsive and braking phases, and lower knee moment impulses during the propulsive phase when compared to the slow limb. The knee moment impulse was also significantly higher during braking in the slow limb than in the fast limb. The mechanics of each limb during the SPLIT session also differed from the mechanics observed when the belt speeds were tied. Based on these findings, we suggest that each belt may have intrinsic value in rehabilitating specific unilateral locomotor deficits.

Effects of dopaminergic therapy on locomotor adaptation and adaptive learning in persons with Parkinson's disease

“…In summary, the kinetics demonstrated during locomotor adaptation followed a similar pattern to those previously reported in healthy young adults [23]. From EARLY to LATE adaptation, the ankle mechanics drive the body forward by generating a progressively greater amount of work, resulting in a greater propulsive GRF impulse.…”

“…However, during conventional gait, it has been well-established that stance phase kinetics (specifically, ankle power production during late stance) have a profound effect on step length [20]. Kinetic changes during SBT adaptation have only recently been studied [21–23] and little is known about kinetic aftereffects and savings during locomotion. A more thorough investigation of the kinetics during late stance could indicate whether kinetic changes drive the kinematic changes occurring during adaptation and adaptive learning (as during conventional walking) or whether they are differentially controlled.…”

The relative contribution of ankle moment and trailing limb angle to propulsive force during gait

“…The variables included in this present biomechanical-based model, ankle moment and TLA, were similar to the variables that were previously identified as the best predictors of AGRF in regression models (Peterson et al, 2010; Peterson, Kautz, & Neptune, 2011; Roemmich, Stegemoller, & Hass, 2012). A previous study investigated ankle, knee, and hip moments during gait and found that only the ankle moment was positively related to propulsion during pre-swing at self-selected walking speed (Peterson et al, 2010).…”

Seeing the Errors You Feel Enhances Locomotor Performance but Not Learning

“…This leaves an open question whether this subtle change in ankle kinematics was sufficient for the nervous system to render the pattern inefficient, discard it, and pursue another through adaptation. This may be possible as the ankle exhibits large kinematic [5] and kinetic [18] changes during split-belt walking. However, we think the most likely explanation is that voluntary changes in movement do not influence one's prediction about the belt speeds, and thus the prediction error driving adaptation is unchanged.…”