Frequency and Circumstances of Falls Reported by Ambulatory Unilateral Lower Limb Prosthesis Users: A Secondary Analysis

Background: More than 50% of lower limb prosthesis (LLP) users report falling at least once a year, placing them at high risk for adverse health outcomes such as decreased mobility and diminished quality of life. Efforts to decrease falls in LLP users have traditionally focused on developing clinical tests to assess fall risk, designing prosthetic components to improve patient safety, and identifying risk factors to recognize potential fallers. Little attention has been directed toward recording, reporting, and characterizing the circumstances of falls in LLP users. Identifying the most common types of falls could help guide and prioritize clinical and research needs. Objective: To characterize the frequency and circumstances of falls reported by unilateral LLP users. Design: Secondary analysis of data from 2 cross-sectional studies. Setting: Outpatient clinic and research laboratory. Participants: Ambulatory unilateral transtibial and transfemoral LLP users (N = 66). Intervention: None. Outcome: A fall-type classification framework was developed based on biomechanical theory and published falls terminology. Self-reported falls and accompanying narrative descriptions of LLP users’ falls in the previous 12 months were analyzed with the framework. Frequencies, estimated proportions, and estimated counts were compared across fall circumstances using 95% confidence intervals. Results: Thirty-eight participants (57.6%) reported 90 falls during the previous year. All reported falls were successfully categorized using the proposed framework. Most falls occurred from disruptions to the base of support, intrinsic destabilizing factors, and a diverse set of fall patterns. Walking on level terrain was the most common activity at the time of a fall. Conclusion: This secondary analysis showed that falls remain frequent in ambulatory LLP users and that clinicians and researchers might wish to prioritize falls owing to disruptions of the base of support that occur while walking. Additional research with a larger sample is required to confirm and expand these results. Level of Evidence: III.