The shoulder is a ball and socket joint where the ball at the end of the humerus (upper arm) fits into the socket of the scapula (shoulder blade).

The joint is meant to be very mobile, allowing movement into many different directions (behind your head or behind your back), generate speed (throwing) while at the same time provide stability (falling or when doing push-ups). 

Key structures that ensure the shoulder joint to function properly and without pain:

• The rotator cuff: A group of muscles and tendons that stabilize and move the shoulder
• The joint capsule and ligaments: a collar of ligaments that help stabilize the shoulder
• The labrum: A ring of cartilage that surrounds the socket, deepening it to make the joint more stable
• The subacromial and subdeltoid bursae: Fatty pads that cushion the tendons and muscles of the shoulder.
• Posture:  The arm’s stable base is formed by the shoulder blade and thoracic spine.  Postural changes or weakness of the back- or shoulder blade muscles can affect the shoulder’s function significantly

Common causes of shoulder pain

Rotator Cuff Injury – Rotator cuff injuries can range from mild to severe.   They can vary between local bruising, tendinitis, small or complete tears.  Tearing could occur from sudden trauma or develop from wear and tear over time (degeneration)

Tendonitis – Tendonitis is an injury caused by either sudden trauma or repetitive stress upon the shoulder’s tendon structures causing it to become irritated and eventually inflamed.  Activities that require overhead movements (like baseball or jobs that require repeatedly reaching upward) are at a higher risk to developing a rotator cuff injury. 

Tendinopathy – This is a wear and tear (degenerative) condition of shoulder joint’s tendon structures that can cause pain and disability.   Fraying of the tendon can lead to chronic tendinitis or small tears

Shoulder Impingement – Shoulder impingement generally occurs after repeated overhead activity, like throwing, swimming, reaching or lifting. Shoulder tendons and bursae get repeatedly compressed between the bones of the shoulder (humerus and acromion) irritating/inflaming the tissue and making it painful to move your arm upwards.

Shoulder impingement can compress and weaken the rotator cuff, further contributing to the problem (see above)

Frozen Shoulder (adhesive capsulitis) – This is a shoulder condition that causes pain and in some cases a large loss in range of motion and function. The first sign of a frozen shoulder is usually pain that limits your arm movement, resulting in stiffness.

Frozen shoulder typically develops slowly, and in three stages; the first stage is characterized by pain, The second stage is where pain subsides and an increasing stiffness begins, and the third stage occurs when the pain becomes less and mobility begins to improve. If untreated, each stage can last from about three to six months.

The exact cause of a frozen shoulder is still unknown but some evidence suggests a link to a problem with the smaller circulation.   Frozen Shoulder is more common amongst women and people suffering from diabetes.

Osteoarthritis – Osteoarthritis can accumulate over time as we get older.  Sometimes this happens without pain while sometimes it is associated with pain.  When cartilage wears down, it becomes pitted, thinner and rougher. This can cause pain within the join or surrounding tissues.

Damaged cartilage can not repair itself as it does not have a blood supply. When cartilage becomes completely worn-down, the cushioning to the bone disappears, causing bone-on-bone contact, crepitus and pain.

Bursitis – This can be a painful condition that affects the small, fluid-filled sacs called bursae that cushion the bones, tendons and muscles near your joints from friction during movement.

When bursae become inflamed, it’s called bursitis. The most common causes of bursitis are repetitive motion, trauma, or positions that impinge the shoulder joint and its structures.

Labral Tears – Traumatically this tends to occur to athletes involved in overhead gymnastic, or heavy contact sports.

When occurring in the non-athletic population it is usually associated with ligamentous/cartilage degeneration.

Some tears are completely asymptomatic and cause no problems. Others can trigger shoulder pain, specifically when moving the arm is moved in an overhead motion or across the chest.

Shoulder Instability – Instability occurs when the shoulder ligaments around the ball of the joint are too loose and unable to keep the joint in place within its socket.

When such a loose shoulder is overused (for instance in the throwing athlete, swimmer or overhead worker), chronic strain, tendinitis and more instability can occur. 

Dislocated Shoulder – When shoulder instability (see above) is extreme, dislocation can occur. 

Partial joint dislocation (or subluxation) occurs when the ball somewhat but not completely shifts out of the socket, and usually pops back in.   Generally, the shoulder feels loose and slips in certain positions especially when the arm is elevated and rotated backwards like when throwing a baseball.

Complete joint dislocation occurs when the ball of the joint fully comes out of its socket.  Generally, this results in the person requiring medical attention to return the joint back into its normal position.  Repositioning the joint without a medical professional could result in irreversible damage from either fracturing the bone or damaging the nerve.

Separated Shoulder – A separated shoulder is an injury to the ligaments that tighten your collarbone (clavicle) to your shoulderblade (acromion):  the Acromio-Clavicular Joint or AC-Joint.

Grade 1:  a relatively mild injury occurring when the AC-Joint ligaments are stretched but not torn.  While this can be quite painful at first, time and rest should heal this injury without any lasting pain or loss of function.

Grade 2:  a mild to moderate injury where the ligaments are stretched and some of them may even be torn.   If enough ligament fibers are torn, the edge of the clavicle bone may pop-up leaving a small bump on top of your shoulder. Usually rest will lead to full recovery without any lasting pain or loss of function.

Grade 3:  a moderate to severe injury where the tearing of the ligaments are severe enough to definitely and irreversibly elevate the end of your collarbone.   While rest will usually lead to full recovery, follow-up with your physiotherapist will help make sure no other potentially perpetuating issues may be complicating things.

Grade 4:  a severe injury where the ligaments stabilizing the AC-Joint are completely torn.  This generally leaves a large bump on top of your shoulder and if pain persists and your function remains compromised significantly, surgery may be necessary to correct it.

Post-Surgery Shoulder – If rehabilitation (conservative treatment) of shoulder pain and injury does not lead to satisfactory recovery or return to function, your surgeon may recommend a surgical procedure to repair or release the damaged structures.

While at all times following your surgeon’s instructions physiotherapy treatment when recovering from surgery is a critical part of optimal recovery to ensure best outcomes for you.

Physiotherapy treatment

Physiotherapy treatment of the above shoulder conditions has been scientifically proven to be helpful to improve pain, help in recovery and deal with chronic symptoms of shoulder pain.  Registered physiotherapists use treatments such as education, self-care management, exercise therapy and manual therapy to treat shoulder pain or dysfunction.

Other treatments such as acupuncture, soft tissue release and massage therapy may also help.  A registered physiotherapist can conduct a skilled assessment and examination of the spine and initiate appropriate treatment.