The supraspinatus is one of the small muscles at the top of your shoulder that makes up the rotator cuff. Strengthen this stabilizing muscle all over your upper-body. 1. Stand holding a light pair of dumbbells in front of your thighs, palms facing each other. 2. Keeping your thumbs pointed up, raise your arms up at a 30-degree angle to your torso until just above shoulder height. 3. Hold for 1 second, and lower to the starting position. 4. Do 2 sets of 8 to 10 repetitions.