Fall Injury Avoidance Strategy Scale (FIAS)—Validation of a Scale to Quantify Fall-Related Protective Movements

OBJECTIVE: To validate the Fall Injury Avoidance Strategy Scale (FIAS), a novel video-based tool to quantify protective movements and injury risk during experimental falls among older adults. DESIGN: Validation study using video-recorded experimental falls from a randomized controlled trial of protective movements. Falls at baseline, postintervention, and 3-month follow-up were analyzed. SETTING: Laboratory setting. PARTICIPANTS: Twenty-three older adults (N=23; aged 66-84y; 19 women) at risk of injurious falls. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Participants underwent 6 standardized experimental falls in backward, left, and right directions. A total of 376 falls across study visits were recorded using motion capture and commercially available cameras. Hip and head peak acceleration were extracted using custom MATLAB scripts. The FIAS score (sum of 4 evidence-based protective fall movements; range, 0-8) and the occurrence of head impact were determined through a secondary video-based analysis by 2 independent raters using a standardized and structured scale. Interrater reliability, construct and content validity, responsiveness, and diagnostic utility of the FIAS score were evaluated. RESULTS: The FIAS score exhibited good interrater reliability (intraclass correlation coefficient (2,k), 0.87; 95% CI, 0.84-0.89; P