Generalization of treadmill-slip training to prevent a fall following a sudden (novel) slip in over-ground walking

Abstract

The purposes of the study were to determine 1) whether treadmill-slip training could reduce the likelihood of falls during a novel slip in over-ground walking, and 2) to what extent such (indirect) training would be comparable to (direct) over-ground-slip training. A treadmill-slip training group (Group A, n=17) initially experienced repeated perturbations on treadmill intended to simulate forward-slip in over-ground walking. Perturbation continued and its intensity reduced when necessary to ensure subjects’ successful adaptation (i.e., when they could land their trailing foot ahead of the slipping foot in at least 3 of 5 consecutive trials). They then experienced a novel slip during over-ground walking. Another 17 young adults in Group B experienced an identical novel slip that served as the controls. They then underwent more slip trials during over-ground walking. Their 16th slip trial was analyzed to represent the over-ground-slip training effect. Eight subjects (47%) in Group A fell upon their first treadmill slip, while all adapted successfully after a minimum of 15 slip trials. Upon the novel slip during over-ground walking, none of them fell in comparison to four subjects (23.5%) fell in Group B upon the same trial (p<0.05). Group A’s control of stability, both proactive and reactive, was significantly better than that of Group B’s on their first over-ground slip, while the level of improvement derived from indirect treadmill training was not as strong as that from direct over-ground-slip training, as demonstrated in Group B’s 16th slip trial (p<0.001). These results clearly demonstrated the feasibility of fall reduction through treadmill-slip training.

Generalization of treadmill perturbation to overground slip during gait: Effect of different perturbation distances on slip recovery

“…Perturbation training is an emerging paradigm to induce fall-resistance adaptation, which is a process of error-driven motor learning (Lockhart, 2008; Pai and Bhatt, 2007; Yang et al, 2013). This kind of learning has also shown a measurable generalization effect.…”

“…In a recent study, significant generalization of training effects was observed from treadmill-perturbation to a novel slip induced during overground walking (Yang et al, 2013). If the treadmill-perturbation training effect on the control of stability can be modulated and generalized to real-life overground slips, then such a device can bring new applications to physical rehabilitation.…”

Adaptive gait responses to awareness of an impending slip during treadmill walking

“…Several techniques have been used to create real-life like slips in a laboratory environment, such as the contaminated surfaces [7][8][9], steel rollers [10], moved force plates [11], movable platforms [12,13], and treadmills [14,15]. Although the approaches of generating slips were various, the experimental protocols were similar among studies.…”

“…Treadmill has been broadly used in biomechanical research primarily due to its inherent advantages [14,17,18]. One of these advantageous features is the control of gait speed.…”

“…Additionally, treadmills with the capability of inducing slip perturbations are increasingly used in the field of fall prevention [14,[18][19][20][21]. It however remains unknown if individuals, when made aware of the impending slip during treadmill walking, would also adapt their gait pattern in response to the potential slip risk.…”