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 subjects 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: A group of active unilateral transtibial prosthesis users of primarily traumatic etiology (PROS) (n=12) with at least one year of prosthetic experience and age and gender matched control participants (CON) (n=12).Interventions: Not applicable.Main Outcome Measure(s): Postural control variables derived from centre of pressure data obtained during the LOS test, which was performed on and reported by the Neurocom Pro Balance Master, namely; reaction time (RT), movement velocity (MVL), endpoint (EPE) and maximum (MXE) excursion and directional control (DCL). Number of falls and total FES-I scores.Results: During the study period, the PROS group had higher FES-I scores (U = 33.5, p=0.02), but experienced a similar number of falls, compared to the CON group. Increased FES-I score were associated with decreased EPE (R=-0.73, p=0.02), MXE (R=-0.83, p less than .01) and MVL (r= −0.7, P=.03) in the prosthesis users group, and DCL (r= −0.82, P less than .01) in the control group, all in the backward direction.ConclusionsStudy 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