Validity and reliability of maximal-strength assessment of knee flexors and extensors using elastic bands.

Context: In the field of sport rehabilitation, an easy, valid, and reliable assessment of maximal strength is crucial for efficient muscle rehabilitation. Classically, it is performed on fitness equipment that is not necessary available in the field. Thera-Band has developed elastic bands with different resistances depending on the color of the band and on the percentage of its stretch. This may allow testing maximal strength. Objective: To determine validity and reliability of maximal-strength assessment of knee flexors and extensors using elastic bands. Design: Reliability and validity study. Participants: 22 healthy participants (31.3 ± 7.0 y, 175.5 ± 8.5 cm, 70.7 ± 12.9 kg). Intervention: Participants performed 2 maximal-strength assessments, separated by 7 d, of the knee flexors and extensors using elastic bands. After the 2nd trial, a maximal concentric isokinetic test at 60°/s was performed. Main Outcome Measures: Correlations between 1-repetition maximum using elastic bands and peak torque on an i...