Absence of improvement with exercise in some patients with knee osteoarthritis: a qualitative study of responders and nonresponders

Key Points

1. Better understanding factors that can potentially influence response to exercise interventions in patients with knee OA can help guide clinicians to identify patients at risk of nonresponse to exercise and consider strategies to optimize outcomes.
2. Responders tended to have a “no pain, no gain” mentality, whereas nonresponders tended to be more resigned about their knee and less accepting of any pain encountered with exercise.
3. Responders had higher adherence to the exercise program and felt empowered to self-manage, whereas nonresponders had suboptimal adherence to the intervention due to pain exacerbations, stressors and/or life events.

BACKGROUND & OBJECTIVE

Although exercise has shown moderate effects on pain and physical function in patients with knee osteoarthritis (OA), it is unclear why some patients with knee OA respond to exercise-based interventions while others do not (1). Qualitative studies can shed light on factors that patients perceive to influence response to exercise-based treatment and in turn, facilitate earlier identification of individuals at risk of nonresponse.

Therefore, the objective of this qualitative study was to compare the perceptions of patients about why they did, or did not, respond to a physical therapist–supported exercise and physical activity program.

It is unclear why some patients with knee OA respond to exercise-based interventions while others do not.

A separate set of less evocative exercises (“rescue program”) can be provided to encourage the patient to continue exercising during a flare-up.

METHODS

This was a qualitative study within a randomized controlled trial. Twenty-six participants with knee OA were sampled according to response (n = 12 responders, 14 nonresponders based on changes in pain and physical function at 3 and 9 months after baseline) to an exercise and physical activity intervention.

For the intervention, physical therapists prescribed an individualized home strengthening program, and provided five consultations over three months to review/modify the program and provide education about OA. Semi-structured individual interviews were conducted exploring participants’ perceptions about why they did/did not respond to the intervention. Thematic analysis was undertaken within each subgroup. Themes and subthemes were compared across subgroups.

RESULTS

Facilitators that were identified by both groups included accountability and monitoring, individualized recommendations with guidance by the physical therapist, and a positive therapeutic alliance with the physical therapist. Although both groups had beliefs about knee OA as a “degenerative” condition, they both felt that there was nothing to lose by participating in the exercise and physical activity program.

Responders tended to have a “no pain, no gain” mentality, whereas nonresponders tended to be more resigned about their knee and less accepting of any pain encountered with exercise. Responders had higher adherence to the exercise program and felt empowered to self-manage, whereas nonresponders had suboptimal adherence to the intervention and accepted responsibility for lack of improvement with exercise. Barriers to the exercise and physical activity intervention were uniquely discussed by nonresponders, and included comorbid conditions, stressors, and life events. Nonresponders also believed that their excess body weight contributed to their outcomes.

LIMITATIONS

This study has limitations that must be considered. The findings of this qualitative study are based on the beliefs and perceptions of twenty-six participants (that were subsequently divided into two separate groups). Although the sample size may affect the generalizability of the study findings, the authors stopped data collection within each subgroup when thematic saturation was achieved. Thematic saturation was deemed to occur when subthemes begin to recur, there were no new themes generated, and there were no new insights related to the research question. In addition, given the qualitative study design, causation of exercise non(response) cannot be inferred.

CLINICAL IMPLICATIONS

The findings of this study can help guide clinicians to identify patients at risk of nonresponse to exercise and consider strategies to optimize outcomes. For nonresponders, exercise often aggravated comorbid conditions (e.g. hip or back pain), causing participants to stop exercising. As a result, proactively screening for comorbid conditions in patients with knee OA and tailoring the exercise program accordingly is recommended.

In addition, nonresponders were more likely to reduce or stop exercise if it aggravated their knee pain. This emphasizes the importance of regularly monitoring the impact of exercise on pain, and modifying the exercise program to ensure that symptoms remain at a tolerable level. It is also crucial to educate and reassure patients concerning pain flare-ups, especially since they commonly occur in response to exercise in patients with knee OA (2).

Furthermore, patients should be provided with tools to help them positively deal with pain flare-ups. For instance, a separate set of less evocative exercises (“rescue program”) can be provided to encourage the patient to continue exercising during a flare-up (3). Self-management strategies should also be provided to improve self-efficacy. Lastly, clinicians should ensure that the exercise program is easy to understand, convenient for the patient and tailored to their lifestyle/schedule to optimize adherence.

+STUDY REFERENCE

Hinman, R.S., Jones, S.E., Nelligan, R.K., Campbell, P.K., Hall, M., Foster, N.E., Russell, T. and Bennell, K.L., 2023. Absence of Improvement With Exercise in Some Patients With Knee Osteoarthritis: A Qualitative Study of Responders and Nonresponders. Arthritis Care & Research.

SUPPORTING REFERENCE

1. Fransen, M., McConnell, S., Harmer, A.R., Van der Esch, M., Simic, M. and Bennell, K.L., 2015. Exercise for osteoarthritis of the knee. Cochrane database of systematic reviews, (1).
2. Parry, E., Ogollah, R. and Peat, G., 2019. ‘Acute flare-ups’ in patients with, or at high risk of, knee osteoarthritis: a daily diary study with case-crossover analysis. Osteoarthritis and cartilage, 27(8), pp.1124-1128.
3. Bartholdy, C., Klokker, L., Bandak, E., Bliddal, H. and Henriksen, M., 2016. A standardized “rescue” exercise program for symptomatic flare-up of knee osteoarthritis: description and safety considerations. journal of orthopaedic & sports physical therapy, 46(11), pp.942-946.