Geoff Ebbs, Strength Coach at UMass Boston, talks about proper jumping mechanics and how to protect an athlete's joints from impact-induced injury. Repetition, Ebbs says, is key to teaching young athletes good form. Doing an exercise as simple as jumping down from a box and landing properly can teach players proper landing mechanics, with knees slightly turned out, knees bent and chest slightly forward. Advance the exercise by having players leave the box with one foot and land two.