For this exercise a fitness-ball is required and can be used to train the lower extremity. The athlete holds the ball in his/her hands. When the lower SmartGoal illuminates, the athlete has to perform a squat to get the ball through the SmartGoal. When the upper SmartGoal illuminates, he/she has to bounce the ball against the wall. For a more challenging exercise, the athlete can stand on a balance pad/ball. | Coach on maintaining a good posture (back straight) while doing squats on different surfaces | Physical: quadriceps, buttock muscles (glutei) |