PJI Hip CARs: Extension/Pelvic Tilt 2/3 Just like with all CARs, different variations can be done to challenge different positions thus different lines of tissue. Hip extension bias CARs are usually done in a quadruped on all fours, but the problem with this is that your knee is limited by the ground so you end up not getting a whole lot of emphasis in the rotational component. Doing them standing, in this fashion at 90 degrees of hip flexion addresses the limitation. Like with most internal tra