Assessment of a Downloadable Application with Avatar Guidance for PT-Prescribed Home Exercise after Total Knee Arthroplasty: A 30-Day Usability and Feasibility Study

Abstract

Objective: To explore the usability and feasibility of a downloadable application (APP) compared to paper handouts (CONTROL) in guiding 30 days of PT-prescribed home exercise after total knee arthroplasty (TKA), and to compare functional outcomes at 30 days postoperatively between APP and CONTROL. Design: Randomized controlled usability and feasibility study. Setting: Rehabilitation laboratories at two regional medical centers. Participants: Individuals with knee osteoarthritis undergoing unilateral TKA (APP group: N = 26; mean age, 67.0 ± 8.2 y; CONTROL group: N = 31; mean age, 64.7 ± 7.7 y). Interventions: This study assessed the user experience of a downloadable app to guide 30 days of home exercises and instruction after TKA and compared exploratory outcomes to a group using paper handouts. Main Outcome Measures: The System Usability Scale (SUS) score was used to assess patient usability experience. Raw SUS scores were dichotomized (≥72% or <72%) to determine app usability against a 75% a priori criterion for mean APP group score. Feasibility for app use was similarly evaluated in the APP group only through a priori criteria applied to computing device ownership and study use, to the absence of technology-based barriers to participation, and to completion of app-based testing. Exploratory measures compared change from baseline to 30 days for functional and patient-reported outcomes between APP and CONTROL. Results: The APP group's mean SUS score of 79.2% at 30 days exceeded the 75% threshold for good usability.