Do Predictive Relationships Exist Between Postural Control and Falls Efficacy in Unilateral Transtibial Prosthesis Users?

Objective: To assess whether variables from a postural control test relate to and predict falls efficacy in prosthesis users. Design: Twelve-month within- and between-participants repeated measures design. Participants performed the limits of stability (LOS) test protocol at study baseline and at 6-month follow-up. Participants also completed the Falls Efficacy Scale-International (FES-I) questionnaire, reflecting the fear of falling, and reported the number of falls monthly between study baseline and 6-month follow-up, and additionally at 9- and 12-month follow-ups. Setting: University biomechanics laboratories. Participants: Participants (N=24) included a group of active unilateral transtibial prosthesis users of primarily traumatic etiology (n=12) with at least 1 year of prosthetic experience and age- and sex-matched control participants (n=12). Interventions: Not applicable. Main Outcome Measures: Postural control variables derived from center of pressure data obtained during the LOS test, which was performed on and reported by the Neurocom Pro Balance Master, namely reaction time, movement velocity (MVL), endpoint excursion (EPE), maximum excursion (MXE), and directional control (DCL). Number of falls and total FES-I scores. Results: During the study period, the prosthesis users group had higher FES-I scores (U=33.5, P=.02), but experienced a similar number of falls, compared to the control group. Increased FES-I scores were associated with decreased EPE (r=-0.73, P=.02), MXE (r=0.83, P<.01) and MVL (r=-0.7, P=.03) in the prosthesis users group, and DCL (r=-0.82, P<.01) in the control group, all in the backward direction. Conclusions: Study baseline measures of postural control, in the backward direction only, are related to and potentially predictive of subsequent 6-month FES-I scores in relatively mobile and experienced prosthesis users. (C) 2018 Published by Elsevier Inc. on behalf of the American Congress of Rehabilitation Medicine.