MUSCLES ENGAGED Hamstrings The hamstrings play a crucial role in many daily activities, such as, running, jumping, walking and cycling. Strengthening your hamstring muscles help to protect your knees from injury by absorbing the stress placed on the knee. Weak hamstrings can lead to knee injury. Calves Calves (calf muscles) influence the ankles and contribute to overall ankle strength. Strengthening your calf muscles will help your balance and performing movements such as running, walking and jumping. Equipment Used Bosu The BOSU balance trainer stands for "Both Sides Utilized" and is most often used for balance training, various athletic drills and aerobic activities. Exercise Instructions Step 1 Start with one foot placed right in the center of the up side down Bosu. Keep a slight bend in your knee and try to disperse your body weight evenly throughout your supporting foot. Step 2 Bend forward and touch the tip of the Bosu with both hands. Step 3 Stand back up and relax your shoulders and supporting foot at the top of the motion.