Maintenance of aquatic training-induced benefits on mobility and lower-extremity muscles among persons with unilateral knee replacement

Valtonen A, Pöyhönen T, Sipilä S, Heinonen A. Maintenance of aquatic training-induced benefits on mobility and lower-extremity muscles among persons with unilateral knee replacement.

Objective

To evaluate the maintenance of observed aquatic training-induced benefits at 12-month follow-up.

Design

Twelve-month follow-up of a randomized controlled study.

Setting

Research laboratory and hospital rehabilitation pool.

Participants

Population-based sample of 55 to 75-year-old women and men 4 to 18 months (on average 10mo) after unilateral knee replacement. Fifty people were willing to participate in the exercise trial and 42 people in the follow-up study.

Intervention

Twelve-month follow-up of 12-week progressive aquatic resistance training, or no intervention.

Main Outcome Measures

Isokinetic knee extensor and flexor power, thigh muscle cross-sectional area (CSA), habitual walking speed, stair ascending time, and sit-to-stand test.

Results

After a 12-month follow-up, a 32% (95% confidence interval [CI], 10–53) training effect in knee extensor power (P=.008) and 50% (95% CI, 9–90) in knee flexor power (P=.005) of the operated knee remained. In muscle CSA, the training-induced benefit had disappeared at the follow-up. All the significant 12-week improvements in habitual walking speed, stair ascending time, and sit-to-stand in the training group compared with controls were lost at follow-up.

Conclusions

After the 12-month follow-up, the 12-week aquatic training-induced benefits in knee extensor and flexor power were maintained, whereas the mobility benefits had disappeared. Aquatic resistance training should be continued at least on some level to maintain the training-induced benefits in mobility.