JMIR Publications

ABSTRACT

Background:

Exercise therapy is recommended by international guidelines as a core treatment for patients with knee osteoarthritis (OA). However, there is a significant gap between recommendations and practice in health care. Digital exercise applications are promising to help solving this undersupply as they allow exercise participation independent of time and location.

Objective:

The aim of the study was to evaluate the efficacy of a 12-week fully automated app-based exercise intervention with and without supporting knee brace on health-related outcomes, performance measures and adherence in patients with knee OA.

Methods:

This closed user group trial included subjects with moderate to severe unicondylar painful knee OA. Randomization was 1:1:2 into an intervention group (IG) with two subgroups (IG-A: app-based training, IG-AB: app-based training and supportive knee brace) and a waitlist control (C). The intervention included a 12-week home exercise program with three sessions per week. The exercises were instructed via the app and the movement performance was monitored using two accelerometers placed below and above the affected knee joint. Participants in C did not receive any study intervention, but were allowed to make use of usual care. OA-specific pain (Knee Osteoarthritis Outcome Score, KOOS) was defined as primary outcome, secondary outcomes included all other KOOS subscales, general health-related quality of life (VR-12), psychological measures (e.g. exercise self-efficacy), performance measures (strength, postural control), as well as the monitoring of adherence and safety. Outcomes were assessed at baseline and after 12 weeks. Intervention effects were calculated by baseline-adjusted analysis of covariance (ANCOVA) for the joint comparison of IG-A and IG-AB versus C using a per-protocol approach. Subgroup analyses were conducted for each IG separately.

Results:

61 subjects were included (IG: n = 30, C: n = 31, ♂ = 31; ♀ = 30; Ø age: 62.9 ± 8.5 years; Ø BMI: 27.7 ± 4.5 kg/m²). Analysis revealed statistically significant effects in favor of IG for pain reduction (P < .001, ES: 0.76), improvements in physical function (P < .001, ES: 0.64), symptoms (P .011, ES: 0.53), sport and recreation activities (P .018, ES: 0.47), knee-related quality of life (P < .001, ES: 0.76) and the physical component scale of general health-related quality of life (P < .001, ES: 0.74). Mean differences ranged from 6.0 to 13.2 points (scale range 0-100). Effect sizes indicated small to medium effects. No effects were found for psychological and performance measures. Participants adhered to 92.5 % of all scheduled exercise sessions.

Conclusions:

Individuals with knee OA undergoing a 12-week sensor-assisted app-based exercise intervention with or without an additional knee brace experienced clinically meaningful treatment effects regarding pain relief and improvements in physical function as well as other OA-specific complaints compared to control. Clinical Trial: German clinical trial register (DRKS00023269).