Current guidelines strongly recommend the use of exercise in the treatment of knee osteoarthritis (OA).1 A systematic review published in 2015 aimed to determine if land-based exercises are beneficial for pain, physical function, and quality of life in patients with knee OA.2 Fifty-four randomized controlled trials were included in the review and most studies had 50 to 150 participants. The studies included a variety of exercises (quadriceps strengthening only, lower limb strengthening, combination strengthening and aerobic exercise, walking programs and ‘others’) at different intensities (low to high), durations (20 to 60 minutes), and frequencies (1 to 5 times per week).
Pooled results from 44 of the 54 studies showed statistically significant pain reduction soon after starting exercise, with a standardized mean difference (SMD) of 0.49 (95% confidence interval [CI] [0.39 – 0.59]), which is equivalent to a 12-point reduction (95% CI [10 – 15 points]) on a 0 to 100 pain scale (0=no pain).2 Twelve of the 54 studies showed a continued statistically significant benefit up to six months after the start of exercise, with an SMD of 0.24 (95% CI [0.14 – 0.35]), equivalent to a 6-point reduction (95% CI [3 – 9 points]) on a 0 to 100 scale (0=no pain). Six of the 54 studies show no significant decrease in pain (SMD 0.08, 95% CI [-0.15 – 0.30]) with exercise after six months. The level of immediate pain reduction was influenced by the number of face-to-face supervised exercise sessions a person had. Supervision allows a safe increase of exercise dose, which improves outcomes. Supervision also allows reassurance and encouragement during pain flares.3 However, a comparison between less than 12 sessions of supervised exercise and more than 12 sessions showed no significant difference in the reduction in pain (p=0.15). There was no difference in pain reduction between the modes of supervision (p =0.14), such as individual treatment, class-based programs, and home programs (exercises supervised by a research team member visiting the home). There was also no difference between the different types of exercise performed (p=0.37) on pain reduction. In general, aerobic, muscle strengthening, and balance/neuromuscular exercises result in similar improvements in pain and disability.4
Another systematic review published in 2016 evaluated the effect of aquatic exercise on pain, disability, and quality of life in patients with knee OA.5 Thirteen randomized controlled trials were included in the review. Participants (n=1190) were mostly female (75%), had an average age of 68 years, a BMI of 29.4, and a 6.7 years average duration of OA. The mean duration of aquatic exercise was 12 weeks. In comparison to no intervention, aquatic exercises showed a significant reduction in pain (SMD -0.31, 95% CI [-0.47 –-0.15]), which corresponded to a 5-point reduction (95% CI [3 – 8 points]) on a 0 to 100-point scale (0=no pain).
- Kolasinski SL, Neogi T, Hochberg MC, et al. 2019 American College of Rheumatology/Arthritis Foundation guideline for the management of osteoarthritis of the hand, hip, and knee. Arthritis Care Res (Hoboken) 2020; 72 (2): 149-162.
- Fransen M, McConnell S, Harmer AR, et al. Exercise for osteoarthritis of the knee: A Cochrane systematic review. Br J Sports Med 2015; 49 (24): 1554-1557.
- Skou ST, Roos EM. Physical therapy for patients with knee and hip osteoarthritis: Supervised, active treatment is current best practice. Clin Exp Rheumatol 2019; 37 Suppl 120 (5): 112-117.
- Juhl C, Christensen R, Roos EM, et al. Impact of exercise type and dose on pain and disability in knee osteoarthritis: A systematic review and meta-regression analysis of randomized controlled trials. Arthritis Rheumatol 2014; 66 (3): 622-636.
- Bartels EM, Juhl CB, Christensen R, et al. Aquatic exercise for the treatment of knee and hip osteoarthritis. Cochrane Database Syst Rev 2016; 3: Cd005523.