Body weight support impacts lateral stability during treadmill walking

Abstract

Body weight support (BWS) systems are a common tool used in gait rehabilitation. BWS systems may alter the requirements for an individual to actively stabilize by 1) providing lateral restoring forces that reduce the requirements for the nervous system to actively stabilize and 2) decreasing the stabilizing gravitational moment in the frontal plane, which could increase the requirements to actively stabilize. The goal of the current study was to quantify the interaction between BWS and lateral stability. We hypothesized that when able-bodied people walk with BWS: 1) the lateral restoring forces provided by BWS would reduce the requirements to stabilize in the frontal plane when comparing dynamically similar gaits, and 2) increasing BWS would decrease the stabilizing gravitational moment in the frontal plane and increase the requirements to stabilize when speed is constrained. Our findings partly support these hypotheses, but indicate a complex interaction between BWS and lateral stability. With BWS, subjects significantly decreased step width variability and significantly increased step width (p < 0.05) for both the dynamically similar and speed-matched conditions. The decrease in step width variability may be attributable to a combination of lateral restoring forces decreasing the mechanical requirements to stabilize and an enhanced sense of position that could have improved locomotor control. Increases in step width when walking with high levels of BWS could have been due to decreases in the gravitational moment about the stance limb, which may challenge the control of stability in multiple planes.

Influence of body weight unloading on human gait characteristics: a systematic review

“…A BWS system is typically composed of an apparatus in which the patient is mechanically supported by a harness while walking on a treadmill or overground [ 8 ]. The constraints and support provided by the BWS system helps the subjects’ vertical alignment and stability of the trunk throughout ambulation [ 8 , 12 ]. This, in turn, can provide neurologically impaired users the confidence to start rehabilitation early after surgery or trauma to regain balance and locomotion without the fear of a fall [ 8 ].…”

Risk-of-falling related outcomes improved in community-dwelling older adults after a 6-week sideways walking intervention: a feasibility and pilot study

“…Therefore, an intervention to improve walking stability in older adults (and decrease fall risk, thereafter) would be more effective if it targeted to decrease the excessive amount of step width variability. Currently, external stabilization devices and body weight support systems can be used to o oad the need of active control and decrease the amount of step width variability during walking [24,[42][43][44][45]. This has implications for walking stability intervention in older adults, which could be directed to exploit the mechanical features of gait dynamics, such as motion-dependent torques [46].…”

“…For example, it was postulated that the ability to gradually o oad the need of active control in treadmill walking through external devices can be used in rehabilitation medicine for walking stability in older adults [21,42]. However, step width variability can be decreased by increasing older adults' ability to control foot placement as well [44].…”

Computational optimization and implementation of control system for mechatronic treadmill with body weight support system

“…A device in which the movement of a training person is limited only by the space of a supporting frame, on which a BWS system moves, has been created as a result of research at the Institute of Theoretical and Applied Mechanics financed by the National Centre for Research and Development . The possibility of free side movements of a patient's pelvis plays a significant role in rehabilitation exercises that restore the proper pattern of walking, as research shows (Dragunas and Gordon, 2016;Mignardot et al, 2017).…”