Clinical scenario: Knee osteoarthritis (KOA) is a complex progressive synovial joint disease that results in impaired muscle function, including a considerable loss of maximal strength and power. Exercise therapies, such as sensorimotor or balance training and resistance training, are frequently used to improve muscle function, mobility, and quality of life, but their impact on maximal muscle strength in patients with KOA is not well understood.
Focused clinical question: Does sensorimotor or balance training improve knee-extensor and knee-flexor maximal muscle strength compared with strength training or no intervention in patients with KOA?
Summary of key findings: Results from 4 fair- to good-quality randomized controlled/clinical trials (level 1b) revealed inconsistent grade B evidence regarding the effect of sensorimotor or balance training to improve knee-extensor and knee-flexor maximal muscle strength in patients with KOA. Two studies, one good-quality study and one fair-quality study, showed significant strength improvements, and 2 good-quality studies demonstrated no significant strength enhancements.
Clinical bottom line: Sensorimotor or balance training may be useful to improve maximal strength of quadriceps and hamstring muscle groups in patients with KOA; however, it seems that this depends on a training duration of at least 8 weeks and the use of unstable devices to induce destabilization of patients' balance, initiating neuromuscular adaptations.
Strength of recommendation: Due to inconsistent evidence (grade B), the true effect of sensorimotor or balance training to improve knee-extensor and knee-flexor maximal muscle strength in patients with KOA remains unclear and needs to be further investigated.
Keywords: exercise therapies; gonarthrosis; muscle function.