Shoulder Pain

Shoulder pain is the 3rd most common musculoskeletal complaint in the general population
The incidence rate is 6.6 to 25 cases per 1000 patients
It accounts for 5% of all general practitioner visits
The peak incidence is 4th to 6th decades
It is 2nd only to knee pain for referrals to orthopaedic surgery
It accounts for 3.9% of new emergency department visits
It accounts for 8% to 13% of athletic injuries

Shoulder impingement

Shoulder impingement is caused by the tendons of the rotator cuff muscles becoming impinged as they pass through a narrow space called the subacromial space. With repetitive pinching, the tendons become irritated and inflamed
Incidence is higher in athletes and labourers
Most common 25-40yrs
Risk factors include prior injury or repeated over head activities
Symptoms include pain on the top/outside of the shoulder as well as when raising arm up and out over the head, pain with overhead activities. In addition, there may be pain after sleeping if arm was outstretched over the head during sleep.

Stretch or tear of the rotator cuff tendon or muscle belly. Grade of strain depends on amount of fibres damaged, degree of pain and strength of muscle contraction.
Risk factors include motions that require repeated overhead motions or forceful pulling motions, sports injuries or trauma, athletes, poor nutrition, obesity, reduced strength and previous injury.
Signs and symptoms include, pain over the top and outside of the shoulder, pain aggravated by leaning on elbow and pushing upwards on shoulder, popping or tearing sensation at moment of injury, followed by pain and weakness, bruising (severe cases), pain at night especially after lying on affected shoulder.

Causes

An idiopathic condition of the shoulder associated with marked shoulder pain and contracture
3 stages- painful: shoulder pain occurs with movement and range of motion starts to become limited. Frozen: shoulder pain may begin to decrease, range of motion substantially reduced (frozen). Thawing: shoulder range of motion begins to improve and return to normal
Onset typically between 40-60 years of age
Risk factors include age, prolonged immobility of shoulder, systemic diseases, prior trauma

Tendons are the tough fibers that connect muscle to bone. For example, the Achilles tendon connects the calf muscle to the heel bone. Most tendon injuries occur near joints, such as the shoulder, elbow, knee, and ankle. A tendon injury may seem to happen suddenly, but usually it is the result of many tiny tears to the tendon that have happened over time.
Doctors may use different terms to describe a tendon injury. You may hear:
Tendinitis. This means “inflammation of the tendon.”
Tendinosis. This refers to tiny tears in the tissue in and around the tendon caused by overuse.
Most experts now use the term tendinopathy to include both inflammation and microtears. But for many years most tendon problems were called “tendinitis.” Many doctors still use this familiar word to describe a tendon injury.

Causes

Most tendon injuries are the result of gradual wear and tear to the tendon from overuse or ageing. Anyone can have a tendon injury. But people who make the same motions over and over in their jobs, sports, or daily activities are more likely to damage a tendon.
A tendon injury can happen suddenly or little by little. You are more likely to have a sudden injury if the tendon has been weakened over time.

Signs & Symptoms

Tendinopathy usually causes pain, stiffness, and loss of strength in the affected area.
The pain may get worse when you use the tendon.
You may have more pain and stiffness during the night or when you get up in the morning.
The area may be tender, red, warm, or swollen if there is inflammation.
You may notice a crunchy sound or feeling when you use the tendon.