Fig. 1.

a–d Illustration of the functional performance tests used to assess knee function following ACLR. a Shuttle run test (adapted from Jang et al. [34]). The athlete performs four lengths of 6.1 m each to complete 24.4 m in the shortest amount of time possible, reversing direction after the completion of each length; b carioca test (adapted from Jang et al. [34]). Using an alternating crossover step, the subject moves laterally to the right 12.2 m, then reverses direction to return to the starting position; c co-contraction test (adapted from Jang et al. [34]). The patient moves in a side step or shuffle fashion around the periphery of a 2.5 m radius semicircle. The test is complete when five semicircle lengths have been performed; d modified t test (adapted from Myer et al. [56]). The test requires a combination of 15 ft of forward running, shuffling and backwards movement to the left side and right sides