Unilateral Strength Training after Total Knee Arthroplasty Leads to Similar or Better Effects on Strength and Flexibility than Bilateral Strength Training – A Randomized Controlled Pilot Study

Abstract

Objective: Unilateral strength training has been shown to be more effective than bilateral training to increase strength in healthy people. The aims of this study were to test the feasibility of unilateral strength training during total knee arthroplasty (TKA) rehabilitation and compare it with standard bilateral training.Methods: Twenty-four TKA patients from an inpatient rehabilitation programme were randomly assigned to unilateral and bilateral strength training groups. Both groups completed 6 strength training sessions during 3 weeks of rehabilitation. Isometric strength, knee joint flexibility, knee circumference, chair rise and walking abilities, and perceived exertion and pain were assessed before and after the training period.Results: Both training groups increased isometric strength of both legs (+17–25%) and flexibility of the affected leg (+7.6%). Improvements in isometric strength of the healthy leg (+23% vs +11%) and flexibility of the affected leg (+10.7% vs +4.5%) were greater in the unilateral training group. Chair rise and 2-min walk test results improved in both groups, to the same extent. Perceived exertion decreased only in the unilateral training group (–20%), while perceived pain did not change in either group.Conclusion: This study showed the feasibility of unilateral strength training in TKA rehabilitation. Strength and flexibility improved similarly or better with unilateral strength training compared with standard bilateral strength training. Future studies should analyse the efficacy of prolonged unilateral strength training following TKA. LAY ABSTRACTThe rehabilitation process following a total knee replacement surgery is aimed at regaining strength and flexibility of the knee joint and improving the movements of daily living, such as walking and standing up from a chair. However, to date, it is not known which kind of strength training is most effective in achieving this aim within a rehabilitation programme. During standard rehabilitation, both legs are trained. The current study tested whether training of the affected leg only is feasible, and compared it with standard strength training of both legs. Training the affected leg only resulted in greater improvements in flexibility and similar or greater improvements in strength. Both types of training resulted in improvements in walking and standing up from a chair. In conclusion, strength training of the affected leg only is a feasible alternative to standard strength training with both legs in total knee replacement rehabilitation.