Stabilize Now: The Safe Shoulder Workout

By Michael Behnken, MS, NASM-CPT-PES, CSCS

Quiz time: Raise your hand if you know the most mobile, yet unstable, joint in the human body? If you guessed the shoulder, you are correct—but put that arm down slowly! Shoulders are ridiculously prone to injury, precisely because they are so mobile and unstable. So while you have to train them to keep them strong enough to support your workout regimen, you also have to be very careful about how you train them. This means having an understanding of shoulder anatomy—and an arsenal of safe exercises.

Mobility and Vulnerability
The shoulder’s mobility is something we take for granted, but it’s a crucial fact of the joint’s architecture. Your shoulder has to allow your arm to move in every possible bodily plane—front and back, up and down, and side-to-side. The range of motion your shoulder can achieve puts your hip—your other largest joint—to shame, and makes the knee look positively primitive. But that range of motion depends on the fact that the shoulder is actually a complex of three bones forming three joints. The result is a range of motion far greater than other joints.

For instance, compare your shoulders to the body’s other ball and socket joint, the hip (or acetabulofemoral) joint. Clearly, the hips are far less mobile. Hips are a ball deeply situated in the socket and held in with large, powerful muscles; by contrast, the shoulder’s major joint, the glenohumoral, has a ball (the head of the humerus, or upper arm) sitting shallowly in its socket and held in place with smaller muscles. With range of motion, therefore, comes delicacy of design; the drawback of being the most mobile joint is that the shoulders are also the most unstable and prone to injury.

The shoulder complex actually involves a large percentage of the upper body’s major muscles, including those of the chest and upper back, but most people are primarily familiar with the deltoids. The deltoids are shaped like a triangle—or the Greek letter Delta, from which they get their name—and they lie over the top of the shoulder down to the upper arm. They are the muscle most often targeted in lifting programs. But in fact, the shoulder’s strength and safety both depend almost entirely on the stabilizing muscles of the rotator cuff. These muscles are both difficult to target and easily injured; they are not a lifter’s dream by any means. But guys who lift ignore their rotator cuffs at their peril. The shoulder is already unstable. To neglect the muscles that, however precariously, provide it with what stability it has is foolhardy at best.

Rotator Cuff Training
There are four rotator cuff muscles, commonly abbreviated by the acronym SITS: the Supraspinatus, Infraspinatus, Teres Minor, and Subscapularis:
  1. Supraspinatus: This small muscle on the upper back of the shoulder lifts the arm straight out to the side (abduction). It is the most frequently injured muscle in the rotator cuff.
  2. Infraspinatus: This is the larger muscle on the rear of the shoulder, running into the upper back. It works on external rotation of the humerus, and carrying the arm backwards. So if your upper arm is at your side, with your forearm horizontally forward, this muscle will let you rotate your forearm out away from you. It protects and stabilizes the back of the shoulder.
  3. Teres Minor: This muscle works with the Infraspinatus for external rotation and to carry the arm backward.
  4. Subscapularis: This is a large triangular muscle on the front of the body. It performs internal rotation of the head of the humerus—so if your forearm is forward and your upper arm at your side, it allows you to cross your forearm over the front of your body. It protects and stabilizes the front of the shoulder.
The vulnerability of these four muscles is a function of their small size and the huge job we ask them to do—especially when lifting. A shoulder’s high degree of movement means it is only as safe as its ability to resist or stop motion. With a weak shoulder and a heavy lifting regimen, trouble is only one dropped weight away. Partly this is a matter of functional anatomy. When training, you want to think of what you ask your muscles—and especially the delicate ones, like those of the shoulder—to do not only in their contracting phase, but in all phases of your movement. This applies to things beyond just shoulder exercises. Anything you lift with your arm must be stabilized by the shoulder, particularly when lowered. But your arm is likely to be much stronger than the stabilizing muscles of your shoulder, so it's easy to end up lifting beyond what the shoulders can stabilize. You have to train your rotator cuffs, not so that they can lift more pounds, but so that they can stabilize more weight throughout your movement.

Of course, all stability begins with your core. It’s no good training your rotator cuff if you have no core stability—you won’t be able to stabilize your shoulders with a shifting core anyway. If you really want to have amazing results, you may need to start off from square one. Begin by performing simple core exercises until your core is strong enough to stabilize your whole body to remain in proper posture.

The RealJock Safe Shoulder Workout
Below you will find several safe exercises for the shoulders. These exercises are designed to work the entire shoulder complex, training the large muscles (the deltoids and trapezius), and the small stabilizing muscles of the rotator cuff as well. While the standing shoulder press is primarily a deltoid exercise, and therefore can be done at heavier weights and fewer repetitions, the other exercises should be done using light weights. All of the other exercises target the rotator cuff in one way or another; all rotator cuff exercises should be done at lighter weights and more repetitions.

Workout: BOSU Balance Trainer
Exercise Muscles Worked Weight Sets Reps
Standing ISO (isolateral, 1-arm) DB Shoulder Press Deltoids, Trapezius Medium-Heavy 3 6 - 10
Seated Modified Arnold Press Deltoids, Trapezius, Rotators Light 3 10-15
Cable Rear Deltoid Raises Deltoids, Trapezius, Rotators Light 3 10-15
45 degree Static Cobra Hold Rotators Light Hold up to 30 seconds 3
Tube Lateral Raises Deltoids, Rotators Light 3 10-15
Tube External Rotation Deltoids, Rotators Light 3 12-20
Exercise Overview
Standing ISO (isolateral, 1-arm) DB Shoulder Press Start facing a mirror in a standing position with your feet together (touching). Bring a single dumbbell up until your elbow is bent at a 90-degree angle with your upper arm parallel to the floor and your forearm vertical. The dumbbell should be directly in line with your ear, with your palm forward. Keeping your core tight and glutes contracted, press the dumbbell straight up until your arm is extended vertically, with your palm still facing forward. Use a weight that not only challenges your shoulders but your core as well. Make sure your shoulders are completely level for the duration of the movement. Be careful not to shrug the opposite shoulder to match the working side. Make sure your resting arm is free and hanging at a natural angle. Your posture should be erect and tight for the entire movement.
Seated Modified Arnold Press Start seated on a bench with back support set upright or very nearly so (80 to 90 percent incline). Hold a dumbbell in each hand right in front of your shoulders at chin level with your palms facing you and your elbows in front of you. In one smooth motion rotate your arms outward to a 90-degree angle, allowing your hands to turn as well, such that your palms come to face forward as your elbows come outward. Just as you reach the 90 degree angle before your arms are completely rotated internally, begin the ascent (keeping both dumbbells in line with your ears) and press the dumbbells above your head until they touch. After the dumbbells touch, rotate your arms so your palms are facing you again. Slowly lower them straight down to the starting position.
Cable Rear Deltoid Raises Stand facing a free motion cable machine with the arms on the lowest or lowest -1 position. Your feet should be hip distance apart with knees very slightly bent. Grab the right handle with your left hand and the left handle with right hand, so that the cables are crossed. Stand with a completely erect posture. Keeping your arms almost straight (slightly bent) and index fingers up, raise your arms straight to the side to until both hands are very slightly above shoulder level. Slowly lower the cables to the original position and repeat. Maintain a tight core and contracted glutes for the duration of the movement.
45-Degree Static Cobra Hold Use a 45-degree angle back extension chair. Hold a position perfectly aligned at 45 degrees. Rotate your arms in external rotation. Your thumbs should be facing as far away from your body as possible. Make sure to keep your core tight and glutes tightly contracted—avoid an arched back. Note that if the extension chair is not available, you may do this exercise on the floor.
Tube Lateral Raises Use a resistance tube or bungee cord. If neither is available you may use small dumbbells or no weight at all. Your arms will be pumped up from the workout to this point and can provide enough resistance on their own. Stand on the tube with one or both feet. Take a handle of the tube in each hand, with arms extended straight down at your sides, and raise the arms directly out to the side, to no higher than shoulder level. For the duration of lateral raises you must keep your hand internally rotated (thumbs down or hands tilted slightly downwards). Lower back to the starting position and repeat.
Tube External Rotation Attach a resistance tube or bungee cord to a fixed point at the level of your belly button. This can be a door knob on a securely closed door, or a weight machine—but it must be an object that won’t move when you pull on it. You may also use a cable machine, if you prefer. Stand with your body in line with the tube, and grasp the handle with the hand further away from the tube’s point of attachment, so that the tube passes across your front. Place your upper arm on that side close against your body, and bend your elbow to 90 degrees, so that your forearm points forward. This is the internal limit of your range of motion—at no point should your hand cross your midline. Now, without moving your shoulders forward or backwards, and keeping your upper arm at your side, rotate your forearm outward as far as it goes—but without generating pain. Repeat using very strict form.
About Michael Behnken: Michael Behnken, MS, NASM-CPT-PES, CSCS, is a fitness specialist working in the San Francisco area. Learn more about him at