The shoulder joint (glenohumeral joint) connects our arms to our trunk and is the most flexible and complex joint in the body. The shoulder joint allows us to move our arm in almost any direction and can perform precise, delicate and powerful actions. The shoulders wide-ranging movements do come at a cost; reduced stability making it prone to dislocation and injury.
The shoulder joint is a ball and socket joint supported by cartilage, ligaments and the biceps and rotator cuff tendons. When assessing the shoulder for injury I don’t only consider the shoulder joint itself, but all its surrounding supporting structures which are known as the shoulder girdle or complex.
The shoulder complex is composed of four joints:
- The shoulder joint (glenohumeral joint), where the humerus joins the shoulder blade (scapula).
- Scapulothoracic joint (where the scapula sits over the ribs).
- Sternoclavicular (where the breastbone joins the collarbone).
- Acromioclavicular joint (where the scapula joins the collarbone).
Types of shoulder injury
Rotator cuff tendinopathy – The most common cause of shoulder pain as a result of micro-tears to the rotator cuff tendons. The rotator cuff is the name given to a group of four muscles that attach to the scapula, they all provide movement and stability to the shoulder joint.
Small tears can occur within the rotator cuff tendons because of; poor posture, unaccustomed heavy lifting, sustained overhead actions and poor flexibility.
You are at an increased risk of developing a rotator cuff tendon injury with age, if you are diabetic or overweight.
Frozen shoulder/Adhesive capsulitis – A condition leading to a thickening of the shoulder joints supporting structures, resulting in stiffness and an inability to move the shoulder.
There are 3 stages of frozen shoulder:
- Initial painful phase – Shoulder pain at rest which can be sharp with movement and keep you awake at night.
- Freezing/stiffening phase – A reduction in pain accompanied by increased loss of movement.
- Thawing phase – Gradual improvements in shoulder mobility.
The cause of frozen shoulder is unclear, however you are at an increased risk if you are female, diabetic, have a thyroid disorder, previous shoulder injury or surgery.
Shoulder Osteoarthritis – The shoulder joint is the third most common large joint affected by osteoarthritis following the knee and hip. Often predisposed by previous trauma/injury which may have occurred years earlier. The gradual loss of joint cartilage and excess bone growth, causes pain, sleep disturbance, joint clicking and reduced mobility. More common in woman and people aged over 60.
Shoulder ligament sprain – Tearing of the shoulders supporting ligaments, most commonly affecting the acromio-clavicular ligaments. Shoulder ligament injuries are often caused by trauma such as a fall, sports collision or road traffic accident. Patients experience swelling, shoulder instability and high levels of pain.
What else can cause shoulder pain? Shoulder pain can also be a symptom of non-muscle and joint diseases such as heart/lung disorders, inflammation of the gallbladder/pancreas and gynaecological conditions. I have been trained to differentiate between joint problems and other diseases and occasionally refer my patients to other healthcare professionals for further investigation.
When treating a shoulder injury I take a global approach and consider how surrounding areas of the body may have predisposed or been affected after the initial injury. Patients with shoulder pain often have additional upper back, neck or elbow complications which are assessed and encompassed within treatment.