Role of stability and limb support in recovery against a fall following a novel slip induced in different daily activities

Abstract

The purpose of this study was to determine whether stability and limb support play a similar role in governing slip outcome in gait-slip as in sit-to-stand-slip, and whether such prediction could also be derived based on measures of these variables during regular, unperturbed movements. Fifty-three and forty-one young subjects all took one recovery step following an unannounced, novel, forward slip induced in gait-slip and in sit-to-stand, respectively. Logistic regression was used to predict recovery outcome based on preslip and reactive measures of stability and limb support across tasks. Following slip onset, all subjects in both tasks experienced rapid decay in stability and limb support (indicated by a hip descent), leading to some actual falls that could not have been predicted from regular, preslip walking. Immediately before recovery step touchdown, stability and limb support could together best predict 88.9% and 100% falls respectively for gait-slip and sit-to-stand-slip. Because of differences in the execution of the recovery step, stability became a better predictor of fallers in sit-to-stand-slip than in gait-slip after recovery limb touchdown. Recovery steps were highly effective in restoring stability, regardless of outcome and task. The predictive strength of stability diminished in gait-slip or reduced in sit-to-stand-slip after touchdown, while limb support remained able to differentiate fallers from those who recovered in both tasks. When slip-induced instability was combined with inadequate limb support, falls were nearly inevitable in both tasks.

Muscle weakness is related to slip-initiated falls among community-dwelling older adults

“…After a slip, to regain body balance and further prevent an actual fall, one must generate timely and sufficient corrective reactions during the recovery stepping (Cham and Redfern, 2001;Yang et al, 2009). Two major reactions to a slip perturbation have been reported previously (Cham and Redfern, 2001;Moyer et al, 2009).…”

Falls-risk post-stroke: Examining contributions from paretic versus non paretic limbs to unexpected forward gait slips

“…Although such an aborted stepping strategy, seen also in a small percent of older adults (Bhatt et al 2005;Espy et al 2010), can be beneficial in that it avoids the risks associated with recovery stepping (e.g. failure of successful step execution due to inefficient vertical stance limb support and step landing) (Pavol and Pai 2007;Yang et al 2009), it can also result in split falls when the slip is "infinite" ). However, this study was limited to slips induced under the nonparetic limb, where the paretic limb was the stepping limb.…”

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.…”

“…Dynamic gait stability has been identified as a key factor resulting in slip-related falls [13]. Technically, dynamic stability is characterized by the relative motion state (i.e.…”