BackgroundThe “Strengthen Your Ankle” neuromuscular training program has been thoroughly studied over the past 8 years. This process evaluation is a part of a randomized controlled trial that examined both the short- and long-term effectiveness of this particular program. Although it was shown previously that the program, available both in a printed booklet and as a mobile app, is able to effectively reduce the number of recurrent ankle sprains, participants’ compliance with the program is an ongoing challenge.ObjectiveThis process evaluation explored participants’ opinions regarding both the methods of delivery, using RE-AIM (Reach Effectiveness Adoption Implementation Maintenance) Framework to identify barriers and challenges to program compliance. Although Reach, Effectiveness, and Adaptation were the focus of a previous study, this paper focuses on the implementation and maintenance phases.MethodsSemistructured interviews and online questionnaires were analyzed using qualitative content analysis. Fisher exact, chi-square, and t tests assessed between-group differences in quantitative survey responses. Interviews were assessed by thematic analysis to identify key themes.ResultsWhile there were no significant differences in the perceived simplicity, usefulness, and liking of the exercise during the 8 weeks of the neuromuscular training program, semistructured interviews showed that 14 of 16 participants agreed that an app would be of additional benefits over a booklet. After the 12-month follow-up, when asked how they evaluated the overall use of the app or the booklet, the users of the app gave a mean score of 7.7 (SD 0.99) versus a mean score 7.1 (SD 1.23) for the users of the booklet. This difference in mean score was significant (P=.006).ConclusionsAlthough both the app and booklet showed a high user satisfaction, the users of the app were significantly more satisfied. Semistructured questionnaires allowed users to address issues they would like to improve in future updates. Including a possibility for feedback and postponement of exercises, an explanation of the use of specific exercises and possibly music were identified as features that might further improve the contentment of the program, probably leading to increased compliance.Trial RegistrationNetherlands Trial Register NTR4027; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=4027 (Archived by Webcite at http://www.webcitation.org/70MTo9dMV)