Wearable Sensor-Based Exercise Biofeedback for Orthopaedic Rehabilitation: A Mixed Methods User Evaluation of a Prototype System

Abstract

The majority of wearable sensor-based biofeedback systems used in exercise rehabilitation lack end-user evaluation as part of the development process. This study sought to evaluate an exemplar sensor-based biofeedback system, investigating the feasibility, usability, perceived impact and user experience of using the platform. Fifteen patients participated in the study having recently undergone knee replacement surgery. Participants were provided with the system for two weeks at home, completing a semi-structured interview alongside the System Usability Scale (SUS) and user version of the Mobile Application Rating Scale (uMARS). The analysis from the SUS (mean = 90.8 [SD = 7.8]) suggests a high degree of usability, supported by qualitative findings. The mean adherence rate was 79% with participants reporting a largely positive user experience, suggesting it offers additional support with the rehabilitation regime. Overall quality from the mean uMARS score was 4.1 out of 5 (SD = 0.39), however a number of bugs and inaccuracies were highlighted along with suggestions for additional features to enhance engagement. This study has shown that patients perceive value in the use of wearable sensor-based biofeedback systems and has highlighted the benefit of user-evaluation during the design process, illustrated the need for real-world accuracy validation, and supports the ongoing development of such systems.

Feedback Design in Targeted Exercise Digital Biofeedback Systems for Home Rehabilitation: A Scoping Review

“…Nineteen articles remained after the screening process, describing 13 separate biofeedback home rehabilitation systems. Eight systems were described by one paper only [34][35][36][37][38][39][40][41], four systems were described by two separate papers [42][43][44][45][46][47][48][49] and one system was described by three papers [50][51][52]. All included papers fulfilled the inclusion criteria for this scoping review.…”

“…Five systems were developed for use in knee rehabilitation (chronic knee pain or post-operative care) [34,35,43,44,49], three for rehabilitation after a cerebrovascular accident (CVA/stroke) [38,46,51], two for elderly at risk of falls [37,43], and one each for rehabilitation related to carpal tunnel release surgery [36], total hip replacement [40], cerebral palsy [39] and chronic obstructive pulmonary disease (COPD) [41].…”

“…While a variety of visual, audio, haptic and multimodal modes could be used, all systems provided feedback of an audio or visual mode, and there was no haptic feedback. The BASE system by Doyle et al [37] featured multimodal feedback, and five systems applied both audio and visual modes [35,[38][39][40]44]. All systems featured concurrent, or 'real-time', feedback, and six of the systems also gave feedback with a time delay [35,38,40,41,43,44].…”

“…Seven systems used descriptive feedback [34,36,37,39,40,43,46], three used both prescriptive and descriptive [35,38,51], one used prescriptive alone [41], and it was unclear what quality of feedback was used in two systems [44,49]. As each system provided feedback on more than one feature of the targeted exercise, KR and KP were noted to be applied in a variety of ways and eight systems applied both KP and KR [35,38,39,41,43,44,46,51]. Five systems used KR only [34,36,37,40,49] and no system used KP only.…”

“…Six main components of exercise were represented in the feedback; these are: ROM, movement (a 'mirroring' of user's movements), repetitions, technique, time spent exercising and reports of progress with, or adherence to, an exercise programme. Exercise components were at times represented in a concrete design style, for example realistic human avatars [35,[37][38][39]41], repetition counters [35,37,41,43,46] and technique feedback via text [35,38,41,49,50]. These designs can be contrasted with abstract avatars [39,43], scores to indicate repetitions [39,40] and colours [43], faces [46] or game features [39] to comment on technique.…”