Reasons for shoulder pain

 

Shoulder pain is a very common occurrence in the middle-aged population and is usually caused by an overuse injury to the rotator cuff tendons (in particular, the supraspinatus tendon) and/or the bursa. The shoulder joint is composed of a round humeral head and a concave glenoid fossa which results in a very mobile ball-and-socket joint that allows great range of motion, but compromises on stability. The four muscles and tendons of the rotator cuff (supraspinatus, infraspinatus, teres minor and subscapularis) in conjunction with the ligaments provide stability to this unstable joint by holding the ball into the socket and allowing the bigger overlying musculature to generate strength and power.

Tendons can become painful (tendinopathy) with sudden changes in activity, repetitive overuse and pressure. This is likely to be more problematic as you age, because ageing tendons are usually less elastic, less tolerable to stress and more susceptible to tearing. The supraspinatus tendon lies over the top of the humeral head and just below the fluid filled bursal sac (a structure that reduces friction and facilitates movement) and both these structures are likely sources of shoulder pain.

Causes

Supraspinatus tendinopathy/bursitis can occur due to compression from above by the acromion (bone) as a result of overhead movement in poor postures that reduce the space under the acromion for the tendon and bursae to move within. Compression can also result from a direct fall/trauma to the shoulder or in rarer cases, it can also be due to a hooked acromion or arthritis.  Imbalances in strength between the four muscles of the rotator cuff, age related tears in the tendons and poor neck and upper back posture can also contribute and cause tendinopathy. Poor control of the muscles around the scapula (shoulder blade) also play a role.

Signs and symptoms:

  • Pain increases with reaching

  • Pain after frequent repetitive activity at, or above shoulder height

  • Weakness with pushing and overhead movements

  • Difficulty sleeping at night due to pain, especially when lying on the painful shoulder

  • Difficulties with simple movements such as; brushing hair, putting on a shirt or jacket, or reaching the arm above shoulder height

  • Limited range of motion in the shoulder

  • Previous shoulder trauma

These signs and symptoms are enough for diagnosis and there is no need to get an ultrasound scan or MRI in the acute phase as it usually will show age related changes in the tendons regardless of pain.

Management:

Conservative management is the preferred treatment option when dealing with a painful shoulder due to supraspinatus tendinopathy and bursitis. A period of relative rest (avoiding aggravating factors) and simple analgesia are important in the early phase. Once the pain is more controlled, a progressive strengthening exercise program for the muscles of the rotator cuff and scapula in conjunction with postural correction have been shown to be the treatment of choice. Your physiotherapist will be able to tailor your exercise program specifically to you in order to address the individual causes that are applicable to your shoulder pain. Surgery is very rarely indicated in this population and would only be a consideration after a failed conservative program and following an informed opinion of a shoulder surgeon.   

Blog by: Sheena Carney, Senior Physiotherapist