MUSCLES ENGAGED Shoulders The shoulder is the most movable joint in the body. However, it is an unstable joint because of the range of motion allowed. This instability increases the likelihood of joint injury, often leading to a degenerative process in which tissues break down and no longer function well. Quadriceps The quadriceps (quads) are a group of four muscles on the front of the thigh. They allow your knee to straighten and provide stability when standing. Your quads are the most important muscle group for maintaining the ability to stand and to walk independently. Equipment Used Kettlebell The kettlebell is a cast-iron weight (resembling a cannonball with a handle) used to perform ballistic exercises that combine cardiovascular, strength and flexibility training. Sizes may range from 4 pounds (1.8 kg) to 175 pounds (79 kg). Exercise Instructions Step 1 Start on your back while holding a kettlebell in one hand directly over top of your shoulder. Step 2 Lower your arm down until your elbow gently touches the floor. You can keep your Step 3 Press the kettlebell back up to the starting position making sure to keep your back firmly on the ground.