The Isokinetic extremity system is the ultimate tool for measuring and improving human performance. Its unique design provides one of the safest ways to test the function of a muscle or a joint. It uses 22 standard test and exercise patterns to precisely identify imbalances between extremities. It is so accurate that the NFL has decided to implement isokinetic strength testing as a mandatory component of the Combine. They test the difference between quad and hamstrings strength to determine the propensity of acl injuries.