BEHAVIOURAL incentive programmes increase physical activity in knee osteoarthritis, while corticosteroid injections show no additional benefit for symptom improvement compared with lidocaine alone.
Incentive Programme in Knee Osteoarthritis
Knee osteoarthritis remains a leading cause of reduced mobility and impaired quality of life, prompting interest in interventions that encourage physical activity. In a pragmatic, multi-site, randomised clinical trial, researchers evaluated whether a behaviourally designed incentive programme could improve activity levels and symptoms in patients with knee osteoarthritis.
The study included 221 participants aged 40–85 years with a clinical diagnosis of knee osteoarthritis and an indication for joint injection. Participants were randomised to receive a behavioural incentive aimed at increasing physical activity.
The primary outcome for activity was average daily step count measured biweekly over 28 weeks and change in the Knee Osteoarthritis Outcome Score (KOOS; average of 5 subdomains) measured bi-weekly between 2-12 weeks after each injection.
Impact On Physical Activity and Symptoms
Participants receiving the incentive programme demonstrated a significant increase in physical activity, walking an average of 771 additional steps per day compared with those not receiving the intervention (p=0.01).
Despite this improvement, no corresponding benefit was observed in symptom outcomes. Knee Osteoarthritis Outcome Score measures, including all five subdomains, were not significantly improved in the incentive group.
These findings suggest that while behavioural strategies can successfully modify activity levels, increased movement alone may not translate into short term symptom relief in knee osteoarthritis.
Corticosteroid Injection Findings
The trial also evaluated the effectiveness of corticosteroid injections compared with lidocaine only injections using a crossover design. Across all time points, corticosteroid injections did not result in significant improvements in symptoms. Time averaged analysis showed no meaningful difference: B: 1.72 (95% CI: -1.08–4.52; p=0.23).
Crossover analysis among 196 participants further supported these findings, demonstrating no benefit of corticosteroids: B: 0.36 (95% CI: -1.17–1.90; p=0.29). Additionally, participants correctly identified the order of their injections in 55% of cases, indicating limited perceptible difference between treatments.
Overall, the study demonstrates that behavioural incentive programmes can effectively increase physical activity in knee osteoarthritis, but do not improve symptoms. Furthermore, corticosteroid injections offer no additional symptomatic benefit over lidocaine alone, raising important considerations for clinical management strategies.
Reference
Baker JF et al. Behavioral incentives for exercise and intra-articular corticosteroids for knee osteoarthritis: results from a factorially designed pragmatic randomized clinical trial. Arthritis Rheumatol. 2026;doi: 10.1002/art.70176.
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