The isokinetic dynamometer is a reliable tool to predict susceptibility to injury (i.e. hamstring strain). The assessment is, nonetheless, limited to an Open Kinetic Chain (OKC) condition, while most injuries in athletic fields have occurred under a Closed Kinetic Chain (CKC) condition (i.e., running, cutting or pivoting). Thus, a hop test has been proposed to assess the CKC function in the lower extremities. However, to our knowledge, there is no study to examine the ability of a hop test for predicting future injuries in the lower extremities. To determine the reliability of a hop test to predict susceptibility to lower limb injuries. METHOD: Sixty-eight college American Football players performed a Single Leg Hop Test (SHT) and a 6-meter Timed Hop test (THT) for each leg before the season. The players were classified into below-average (BA) and above average (AA) groups according to the score of the SHT and THT, respectively. A certified athletic trainer recorded two types of injuries throughout the season: muscles strain occurred to thigh or calf and ligamentous injuries occurred to knee or ankle. The incidence of those injuries was compared prospectively. RESULT: Chi-square analysis found a significant difference (p < 0.05) in the number of muscle strain injuries between the BA and AA group in the THT (Table 1), but not in the SHT. The individuals with lower physical ability in the THT have a higher risk for muscle strain. A Timed Hop test will be used to identify the individual at a risk for muscle strains at lower limb.