The Effects of a Digital Exercise Therapy Application for Patients with Shoulder and Knee Pain During the COVID-19 Pandemic

Objective: To examine changes in function and pain interference among patients utilizing a digital exercise therapy application (DETA) for knee and shoulder pain. Methods: We conducted a retrospective analysis of data from patients utilizing a DETA for non-operative knee and shoulder pain. Primary outcomes for the study were 8-week changes in physical function, measured using the PROMIS-Physical Function (knee pain) and PROMIS-Upper Extremity Function (shoulder pain); and pain interference, measured using the PROMIS-Pain Interference. Data on patient characteristics was used to examine outcomes among specific patient subgroups. Results: We observed a 3.5 point (SD: 7.8) increase in function and a 3.9 point (SD: 7.5) decrease in pain interference overall (p<0.001), with changes in function and pain interference surpassing the minimal clinically important difference for patients with knee and shoulder pain. Patients with knee pain experienced greater improvements in function than those with shoulder pain (p=0.02), as did patients who report moderate-high levels of exertion during exercise compared to those reporting low levels of exertion (p=0.05). We saw greater reductions in pain interference among those with higher education (p=0.03), those with more acute symptoms (p=0.01) and those reporting moderate-high levels of exercise exertion (p=0.02). Conclusion: We observed a clinically meaningful improvement in pain interference and function among patients utilizing a DETA for knee and shoulder pain. Patients with knee pain, higher levels of education, more acute symptoms, and those who reported higher levels of exertion with exercise experienced the greatest changes in function and pain. Impact Statement: This study indicates that self-guided interventions, such as those delivered through a DETA, may be beneficial for patients with knee and shoulder pain. These results may also inform the development of patient profiles that can be used to identify patients most appropriate to receive care through a mobile application.