Home » Chronic Shoulder Pain: A Matter of Anatomy?

Chronic Shoulder Pain: A Matter of Anatomy?


Shoulder injuries and pain are common in a variety of sports. Whether it is in throwing a pass in football or a pitch in baseball, athletes need tremendous shoulder strength and coordination to achieve athletic excellence.  But the constant strain and pressure on the shoulder often leads to irritation and can result in an overuse injury.  

Young baseball pitcher about to deliver pitch

As a physical therapist, I am often asked why some athletes seem more prone to shoulder injuries than others, how shoulder injuries are treated when they occur, and how can the risk of injury or re-injury be reduced? To answer these questions, we need to start with a discussion of the anatomy of the shoulder. 

Shoulder anatomy can effect risk

While the basic structure of the shoulder is the same for every athlete, there are important differences between athletes.  First, the shoulder joint is inherently a very unstable joint. The ligaments around the shoulder joint are supposed to hold it in place and provide stability.  When those ligaments are loose (what we PTs call "lax"), the joint requires more muscle strength to maintain support, so if those muscles aren't strong, the risk of injury increases.   

Second, other structures around the shoulder joint can increase the risk of injury. A young athlete with scoliosis, congenitally weak neck muscles or spinal vertebra, or poor (e.g. flexed or bent) spinal posture will have trouble keeping the shoulder joint stable.  While these deficiencies can be corrected to an extent through training, such underlying conditions will cause the athlete to work harder to maintain balance in the shoulder.

Finally, the shape of the acromion - a hook shaped bone that sits off the rotator cuff - can effect stability: some have a shape that permits increased clearance in the shoulder joint while others are hooked-shaped, increasing the risk for pinching or tearing on the rotator cuff.

Injury history: past as prologue

As with any joint, previous injury is one of the strongest indicators for future injury.

  • Compromise to the ligamentous integrity of the shoulder joint, such as a labral tear, increases instability in the shoulder joint, which causes muscles around the shoulder joint to work harder to maintain stability. 
  • Rotator cuff injuries, including chronic strains and tears, affect shoulder timing and overall joint stamina with overhead activities.
  • Weakened rotator cuff muscles make "steering" the shoulder difficult, sometimes resulting in significant damage to the joint and surrounding soft tissue.

Sport affects injury risk

Repetitive overhead motions put the shoulder at greater risk for injury. Baseball, softball, tennis, swimming, and volleyball are a few examples of sports involving repetitive overhead motions. Athletes who sustain repeated hits to the upper body, such as in football and wrestling, are also at increased risk of traumatic injury to the shoulder joint. The fact that the majority of injuries to the shoulder joint result from repetitive motion, regardless of sport, suggests there are ways to avoid serious injury.

Concerning signs

An athlete experiencing any of the following symptoms should be immediately evaluated by a physician:

  • Pain while sleeping / inability to lay on shoulder
  • Tenderness to light touch over the shoulder joint
  • Complaints that shoulder is "catching" "locking up" or "feels like it is going to pop out"
  • Pain that is progressively getting worse or does not improve after a week 
  • Radiating pain from the shoulder joint to the neck, arm, or hand
  • Inability to perform common tasks: reaching into the pantry, carrying book bag, putting on a shirt
  • Numbness in the shoulder, arm, or hand

The failure to immediately address and treat any of these symptoms will put the athlete at risk of a more severe injury.  Even at this stage, the majority of injuries that are addressed medically will resolve in time. Allowing an athlete to continue play increases risk of a severe injury that will permanently affect sport performance for their remainder of their career.

Building a foundation for success

So on what does the athletes need to focus in order to avoid injury and stay on the field? There are many shoulder exercises and training regimens that will maximize an athletes potential. The most important, and often overlooked, exercises for the shoulder are the ones that build a foundation of support.

  • Pectoralis Major and Minor Stretching - Place 90 degree bent elbow at chest level against a doorway and lean in, holding for 20-30 seconds. Repeat 2-3 times and then repeat this same exercise with the arms at the sides, about 45 degree angle from the body.
  • Prone Shoulder Flexion and Horizontal Abduction - These two exercises stress the mid and lower trapazoids, as well as the paraspinals running up and down the back that provide support for the shoulder girdle. The most important part of these two exercises is technique. The focus of the exercise should be squeezing the shoulder blades together, not tightening up the neck. High repetitions (20-30 reps) and sets (3-4 sets) with lighter weight (2-5 pounds) are preferable as these muscles are stabilizers and required a great deal of endurance.
  • Push Up with a Plus - This particular exercise maximizes stimulation of the serratus anterior, a group of finger-like muscles pulling off the ribs the produces a "punching" motion with the arm. With the elbow locked out in a push up position, press down through the arms to round the shoulders. This particular motion will focus on the muscle but not as much the chest, which, when tight, has a tendency to increase risk for shoulder impingement.
  • 90/90 External Rotation with Resistance Bands - With a light resistance band attached at head level, perform this exercise with the arm at shoulder level and elbow bent to 90 degrees. Rotate the shoulder backward into external rotation quickly (1 second) and then slowly return to beginning position (3-5 seconds). The importance of this slow return is to build the eccentric component of the rotator cuff, a mechanism that prevents the shoulder from dislocating when throwing a ball. The elbow is not to drop below the level of the shoulder. High repetitions, 2-3 sets, and light resistance band are recommended. Form is very important with this exercise, so pay attention!

Posted March 5, 2013.
Look for Keith in MomsTEAM's high school football concussion documentary, "The Smartest Team."