Few joints are as multipurpose as the human shoulder. We can walk on our hands, crawl and do push ups. The shoulder is a very sturdy join. Yet no joint in the human body is as mobile. Known as a “ball and socket” joint, the shoulder is essentially a pool ball freely rotating in a tea cup saucer. This allows for free rotation of the arm in all directions. You can literally wave your hands and arms in perfect, large circles as though they were helicopter blades. In comparison, your knee only folds and straightens. It is called a hinge joint for that reason. Even your cervical spine (neck), which does allow for tremendous free movement, does not have as much range of motion as the famous shoulder joint.
The hip joint is also a ball and socket joint, but as you can see, the ball of the femur bone is sunk in to a deep socket on the pelvis. 
This restricts the amount of movement the legs have, but it replaces it with sturdiness so you can ran and jump without dislocation your hips. This is the down side of the free wheeling shoulder; because it is such a shallow joint, it requires ligaments and tendons to keep it from dislocating. And because we use our arms for heavy lifting and pushing, we are susceptible to injuring shoulders easily.
Because there is no deep bone locking between the arm and shoulder blade, the sturdiness of the shoulder comes from the muscles of the shoulder region. To make this more clear, remember that the socket joint for the arm bone is on a free floating shoulder blade (known as the “scapula”). The scapula is not connected to your rib cage, it simply floats on top of your ribs, held only by a large pool of muscles (e.g.: rhomboids, trapezius, serratus, lats, etc).
Now, the scapula’s only connection to your skeleton is where it touches the end of your collar bone, which then tags your sternum at the top of your chest. This small collar bone (i.e.: clavicle) is the only relay for the scapula and arm to the skeleton. The rest simply float in pools of muscle. This game of relay between your scapula and your clavicle and then your sternum does not provide stability, it simply provides a “spacer” to prevent too much movement of the scapula (i.e.: shoulder blade). In fact, it is common for weight lifters who bench 300 lbs or more on a regular basis to have the outside third of their clavicle bone (i.e.: collar bone) completely resorbed and replaced with pure muscle and connective tissue. So clearly, the star of the show in arm and shoulder strength and stability is purely muscle, not bone. This is why the shoulder is one of the joints that benefits the most from manual therapy and exercise rehabilitation.
above image is a public domain gif from wikipedia
By far the most common shoulder complaints I get as a clinician is what is called “impingement syndrome.” This is a condition in which there is sharp pain in the front or top of shoulder when patients move their arms overhead. The reason for this pain is that, as our rotator cuff muscles and other shoulder muscles get either too little exercise or too much of an unbalanced exercise, our arm bone grates the acromion bone above when we raise our arms. As you can see in the above motion image, there are muscles between the arm bone and the bony roof created by the acromion. This can result in soft tissue damage and/or inflammation as the soft tissue experiences a grinding from the bones. By balancing the muscular activity, strength and flexibility in the rotator cuffs and other shoulder girdle muscles, this imbalance can be fixed. Active release and other joint mobilizations are often also required in order to break down scar tissue that has formed after impingement syndrome has been a problem for awhile.
The rotator cuff muscles act to hold the arm bone in proper place in the shoulder joint, therefore their strength and endurance are paramount in fixing impingement syndrome.
rotator cuffs allowing for proper tracking of humeral head as it articulates with the scapula in the shoulder joint
The following are samples of some of the exercises we use to rehabilitate an improperly functioning shoulder. We use these for a variety of conditions such as:
- impingement syndrome
- frozen shoulder
- rotator cuff tears
- SLAP lesion recovery
- and many others
Now please do not self diagnose or begin to perform the following exercises until you have been properly evaluated by your chiropractor, physiotherapist or doctor. We only include these examples to educate you on what a proper shoulder program can look like.
1. BALL CIRCLES
2. BEHIND-THE-BACK THERABAND PUMPS
3. BICEP CURLS + THERABAND PUNCHES
4. BOSU BALL + TOE SWIVELS + PIKES
These exercises are only good for you if your practitioner has properly evaluated you and feels you have received the proper manual and physical therapy to ready you for active rehabilitation. Come see us if your shoulders are not performing as the superstars they were designed to be!
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