Benefits and Mechanisms of Exercise Training for Knee Osteoarthritis

Chu-Yang Zeng,Zhi-Ming Tang,Zhen-Rong Zhang,Fu-Zhou Hua

doi:10.3389/fphys.2021.794062

Abstract

Knee osteoarthritis is a chronic degenerative disease. Cartilage and subchondral bone degeneration, as well as synovitis, are the main pathological changes associated with knee osteoarthritis. Mechanical overload, inflammation, metabolic factors, hormonal changes, and aging play a vital role in aggravating the progression of knee osteoarthritis. The main treatments for knee osteoarthritis include pharmacotherapy, physiotherapy, and surgery. However, pharmacotherapy has many side effects, and surgery is only suitable for patients with end-stage knee osteoarthritis. Exercise training, as a complementary and adjunctive physiotherapy, can prevent cartilage degeneration, inhibit inflammation, and prevent loss of the subchondral bone and metaphyseal bone trabeculae. Increasing evidence indicates that exercise training can improve pain, stiffness, joint dysfunction, and muscle weakness in patients with knee osteoarthritis. There are several exercise trainings options for the treatment of knee osteoarthritis, including aerobic exercise, strength training, neuromuscular exercise, balance training, proprioception training, aquatic exercise, and traditional exercise. For Knee osteoarthritis (KOA) experimental animals, those exercise trainings can reduce inflammation, delay cartilage and bone degeneration, change tendon, and muscle structure. In this review, we summarize the main symptoms of knee osteoarthritis, the mechanisms of exercise training, and the therapeutic effects of different exercise training methods on patients with knee osteoarthritis. We hope this review will allow patients in different situations to receive appropriate exercise therapy for knee osteoarthritis, and provide a reference for further research and clinical application of exercise training for knee osteoarthritis.

Highlights

Knee osteoarthritis (KOA) is a chronic degenerative disease which often causes disability and pain (Madry et al, 2016); especially in people over 50 years of age (Abbassy et al, 2020)
Physiotherapy has its limitations, which should combine with surgery
It is very necessary to find a non-surgical treatment to effectively relieve the symptoms of patients with KOA

Summary

INTRODUCTION

Knee osteoarthritis (KOA) is a chronic degenerative disease which often causes disability and pain (Madry et al, 2016); especially in people over 50 years of age (Abbassy et al, 2020). Various animal experiments of the exercise training to treating KOA have suggested that exercise training can increase muscle cross-sectional area, decrease muscle fiber density, change the tendon structure, delay musculoskeletal atrophy, stabilize the osteoarthritis joint, inhibit inflammation, rescue synovial cell dysfunction, and prevent cartilage degeneration and the loss of subchondral bone (Figure 3). These studies provide an experimental foundation for the application of exercise training in the treatment of KOA, which may be beneficial for patients with this disease. BMI, body mass index; CRP, C-reactive protein; IL-6, Interleukin-6 ISK; the index of severity for knee osteoarthritis; KOOS, Knee Injury and Osteoarthritis Outcome Score; RCT, randomized controlled trial; SF-36, Medical Outcomes Study Short-Form Health Survey; TNF-α,Tumor Necrosis Factor-α; TST, timed-stands test; TUG test, Timed Up and Go test; VAS, Visual Analog Scale; WOMAC, Western Ontario and McMaster Universities Osteoarthritis Index; 1-RM test, one repetition maximum test; 6-MWT, 6-min walk test; and 30s CST, 30 s Chair Stand Test

Study design

CONCLUSION

Findings

DATA AVAILABILITY STATEMENT