Impact of Functional Knee Brace Removal After Use and Prolonged Use on Anaerobic Endurance and Aerobic Capacity Performance

Objective: Published data suggest that knee brace use may reduce the risk of primary noncontact knee ligament injury. However, the use of knee braces remains contentious due to concerns about performance hindrance. As knee brace use is a potentially modifiable risk factor, this study aimed to identify whether after 17.5 hours of functional knee brace (FKB) use, discounting and continued use of FKB hamper performance during anaerobic and aerobic tasks. Design: Prospective repeated-measures crossover study. Setting: Academic laboratory testing. Participants: Twenty-seven healthy male provincial basketball and national field hockey athletes. Interventions: Over 6 days of 12 testing sessions, during 3 test conditions (nonbraced, braced, and removed brace or continued brace use), anaerobic and aerobic performance was evaluated after removing a custom-fitting FKB after 17.5 hours and with continued FKB for 21.0 hours. Main Outcome Measures: Anaerobic and aerobic, predicted maximum oxygen uptake (V̇O 2max ), performance. Results: In the anaerobic endurance test, after 17.5 hours of FKB use, FKB removal led to a slower performance of nonsignificant 0.27 ± 0.26 s and higher fatigue levels ( P = 0.741, 95% CI, 16.00-17.23, Cohen effect size (ES) = small); continued FKB use for 21 hours resulted in nonsignificantly 0.25 ± 0.24 s faster performance and lower fatigue levels ( P = 0.626, 95% CI, 15.96-16.94, ES = trivial). In the aerobic capacity test, FKB removal resulted in a nonsignificantly lower V̇O 2max (3.0 ± 0.5 mL·kg −1 ·minute −1 , P = 0.518, 95% CI, 43.58-45.62, ES = large); continued FKB use led to a significantly higher V̇O 2max (1.5 ± 0.5 mL·kg −1 ·minute −1 , P = 0.005, 95% CI, 46.72-48.54, ES = large). Conclusions: Removal of FKB led to lower performance levels in both tests, while prolonged FKB use resulted in greater anaerobic endurance, lower fatigue level, and significantly higher aerobic capacity performance. Clinical Relevance: These findings should help the decision-making process of practitioners about FKB use and performance.