Distinguishing retrospective fallers from nonfallers in people who use a unilateral lower-limb prosthesis.

Background: Over 52% of people who use a lower-limb prosthesis fall once every year, but fall risk is still not effectively screened. Few studies have identified clinical outcome measures that could help screen fall risk. Gait asymmetries between the intact and prosthetic limbs could also potentially help identify fall risk, based on findings in people with stroke. However, no studies have examined the relationship between gait asymmetries and falls in people who use a lower-limb prosthesis. Therefore, we sought to determine if any gait asymmetry parameters could significantly distinguish 12-month retrospective fallers from nonfallers.

Methods: People were recruited from private practice and the Amputee Coalition National Conference. Participants completed a 12-month retrospective fall history and 7 clinical outcome measures, as well as level-ground walking at self-selected pace with wearable sensors that collected kinematic (sagittal plane: hip, knee, and ankle range of motion) and kinetic (peak braking and propulsion ground reaction force) data.

Results: Twenty-two individuals who use a unilateral prosthesis participated (age 57.6 ± 14.2 years; 15 transtibial, 7 transfemoral). No gait asymmetry parameters significantly distinguished 12-month retrospective fallers from nonfallers. However, the Four Square Step Test did significantly distinguish fallers from nonfallers (P = 0.040, Hedge g = -0.739, area under the curve = 0.725, CI = 50-95%, cutoff time = 13.14 s), irrespective of level of prosthesis use. No parameters significantly distinguished fallers from nonfallers by level of prosthesis use (transtibial, transfemoral).

Conclusions: The Four Square Step Test cutoff time may be useful to distinguish fallers from nonfallers in unilateral lower-limb prosthesis users.