Evaluation of the acceptability and usability of a digital biomechanical biofeedback toolkit for the physiotherapy management of chronic knee pain

Subahi, Mohammad 2025. Evaluation of the acceptability and usability of a digital biomechanical biofeedback toolkit for the physiotherapy management of chronic knee pain. PhD Thesis, Cardiff University. Item availability restricted.

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Abstract

Introduction: Chronic knee pain (CKP) causes considerable burden on peoples’ quality of life and everyday activity. For effective care of CKP, novel solutions including digital health interventions are required. While exercises are widely regarded as a key therapeutic approach and biofeedback is considered effective particularly in enhancing patient engagement, both lack objective assessment methods, such as movement analysis, to guide and inform personalised exercise prescriptions in the clinic. Furthermore, adherence to home exercise programmes remains low, and current digital health interventions rely primarily on patient-reported outcome measures (PROMs). Therefore, complementing traditional assessments supplemented with movement analysis in the context of digital health interventions could be an effective strategy to adopt. However, there are still gaps on whether such interventions are acceptable and usable to influence clinical decision making of exercise prescription, engage CKP individuals with their condition management, track progress, and encourage home exercise adherence. Aim: To evaluate the acceptability and usability of a digital biomechanical biofeedback toolkit (DBBT) for the physiotherapy management of individuals with chronic knee pain. Objectives: (1) To explore the acceptability and usability of the DBBT, (2) To observe changes in biomechanical parameters, including kinematics and spatiotemporal measures, before and after the use of the DBBT, (3) To observe perceived changes in PROMs responses over the duration of the study. Methods: A mixed-methods study was conducted using a pre-post experimental design. The study was ethically approved from Cardiff University ethics committee and twenty-five individuals with CKP were eligible to participate and consented to take part in the study. Inclusion criteria were adults aged 18 years or older with self-reported knee osteoarthritis and activity-related pain, reporting knee pain on most days for at least three months with an average severity of ≥4/10. Exclusion criteria included non-knee musculoskeletal pain, contraindications to exercise, pain due to malignancy, fractures, or inflammatory arthritis, recent knee surgery (within 12 months), recent new treatments (within 12 weeks), concurrent physiotherapy, or previous knee arthroplasty. Participants engaged with the DBBT for a duration of two weeks. The DBBT components are: (1) Xsens wearable sensors to collect gait data ii | P a g e via MVNX Analyze software; (2) MotionCloud, which processed this data and generated gait reports; (3) Kinduct web platform to create participant profiles, deliver personalised exercise programmes, send reminders, and track exercise and PROMs completion; and (4) Kinduct mobile app, used by participants at home to view exercises, receive reminders, log exercises, and submit PROMs. Acceptability was evaluated through semi-structured interviews using the theoretical framework of acceptability (TFA), analysing all seven constructs deductively. Usability was assessed using the system usability scale (SUS) and usage adherence rates of two tasks including logging exercise sessions and submitting PROMs. Supplementary outcomes included kinematics and spatiotemporal parameters, and PROMs including validated measures for pain, disability, and psychological factors as follow, WOMAC, Tampa Scale, PHQ-9, SES6G, and NPRS. Results: There were (n = 14) male participants and (n = 11) female participants with a mean age of 37 ± (16.03) years. The mean BMI was 26 ± (2.9) kg/m². Acceptability was high, as indicated by thematic analysis findings structured using the TFA. Participants’ responses reflected strong alignment with key TFA components including affective attitude, perceived effectiveness, and intervention coherence. These perceptions were shaped by specific DBBT features including personalisation, visual biomechanical biofeedback gait report, reminding system, video demonstrations, and exercise logging and PROMs submission features. Usability was also high with an excellent SUS score (81.2), and high adherence rates for both exercise logging (63%) and PROMs submission (72%). Supplementary kinematic, spatiotemporal, and PROMs data further contextualised these findings, showing participant movement and symptom profiles consistent with similar clinical populations and reinforcing the relevance of the DBBT in home-based rehabilitation settings. Conclusions: The DBBT was found to be highly acceptable and usable in a mixed-methods evaluation involving individuals with CKP. Participant engagement was shaped by key features including visual biomechanical biofeedback gait report, reminding system, video demonstrations, and exercise logging and PROMs submission features, which aligned with core components of the TFA. Usability was supported by a high SUS score and adherence to both exercise logging and PROMs submission. Supplementary biomechanical and self-reported data contextualised iii | P a g e these findings and confirmed the DBBT’s relevance to this population. The DBBT offers a promising, personalised approach to technology-enhanced physiotherapy and warrants further investigation in larger-scale studies. However, the relatively small sample size, limited clinical testing environment, and potential for minor measurement variability in kinematic data collection may limit the generalisability of the findings and should be considered when interpreting the results.

Item Type:	Thesis (PhD)
Status:	Unpublished
Schools:	Schools > Healthcare Sciences
Date of First Compliant Deposit:	26 January 2026
Last Modified:	26 Jan 2026 15:08
URI:	https://orca.cardiff.ac.uk/id/eprint/184093

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