Rotator Cuff & Shoulder Impingement

The shoulder is the most mobile joint in the human body, which also makes it one of the most vulnerable to injury. Two of the most common sources of shoulder pain seen in clinical practice are rotator cuff injuries and shoulder impingement syndrome, and they frequently occur together.

The rotator cuff is a group of four muscles and their tendons (the supraspinatus, infraspinatus, teres minor, and subscapularis) that surround the shoulder joint and keep the head of the humerus seated firmly in the shallow socket of the shoulder blade. Rotator cuff injuries range from tendinopathy and partial tears to full-thickness tears of one or more of these tendons. Shoulder impingement syndrome occurs when the tendons of the rotator cuff become compressed or irritated as they pass through the subacromial space, the narrow gap between the top of the humerus and the acromion bone of the shoulder blade.

Causes of Rotator Cuff Injury

Rotator cuff injuries are most commonly the result of repetitive overhead activity, cumulative wear over time, or a sudden acute event such as a fall or a forceful lifting movement. The supraspinatus tendon is the most frequently injured, in part because of its position within the subacromial space where mechanical compression is common.

Shoulder impingement develops when the subacromial space is narrowed due to bony changes, soft tissue swelling, poor posture, or muscle imbalances that alter the mechanics of the shoulder joint. Both conditions share an underlying pattern of tendon degeneration rather than simple inflammation, a finding consistent with research on tendinopathies throughout the body¹.

Risk Factors

Repetitive overhead activity (painting, swimming, throwing sports, overhead lifting)
Advancing age, particularly after 40
Poor shoulder blade stabilization and posture
Occupations requiring sustained or repeated arm elevation
Previous shoulder injury or surgery
Bone spurs on the acromion
Weakness of the muscles surrounding the shoulder blade (periscapular weakness)

Symptoms of Rotator Cuff Injury

The most common symptoms of rotator cuff injury and shoulder impingement include:

Pain at the top or front of the shoulder, often radiating toward the outer arm
A painful arc of motion, typically when lifting the arm between 60 and 120 degrees
Weakness with reaching overhead or behind the back
Difficulty sleeping on the affected side
A catching or clicking sensation with shoulder movement in some cases

Symptoms may develop gradually with repetitive strain or appear suddenly after an acute injury.

Diagnosis

Diagnosis begins with a thorough history and physical examination, including orthopedic tests such as the Neer sign, Hawkins-Kennedy test, and empty can test to assess impingement and rotator cuff integrity. Imaging is often used to confirm the diagnosis: X-ray can identify bony changes or acromial morphology, while MRI or ultrasound provides detailed visualization of the tendons and surrounding soft tissue, allowing partial or full tears to be distinguished from tendinopathy².

Conventional Treatment

Initial management of rotator cuff injuries and shoulder impingement typically involves relative rest, activity modification, and a course of physiotherapy focused on rotator cuff strengthening and restoring normal scapular mechanics. Non-steroidal anti-inflammatory medications are commonly used for short-term pain management.

When conservative measures fail to provide adequate relief, corticosteroid injections into the subacromial space are frequently offered. While these injections can reduce pain in the short term, research indicates that repeated corticosteroid injections may weaken tendon tissue over time and do not address the underlying degenerative changes driving the condition³. For full-thickness tears or cases that have not responded to other treatment, surgery may be recommended, though recovery is lengthy and outcomes are variable depending on tear size and tissue quality.

Regenerative Treatment Options

Regenerative injection therapies offer an evidence-based approach to shoulder pain that works with the body’s own healing mechanisms rather than simply suppressing symptoms.

Prolotherapy involves the injection of a concentrated dextrose solution at sites of tendon and ligament injury. This mildly irritating solution triggers a controlled healing response, promoting the laying down of new collagen and improving tissue integrity over time. Prolotherapy has been used for decades to treat tendinopathies and joint instability, including injuries of the rotator cuff.

Prolozone therapy combines ozone gas with prolotherapy solutions. Ozone is a powerful stimulant of tissue oxygenation and cellular repair. By enhancing local oxygen delivery to an area of chronic, poorly vascularized tendon injury, prolozone therapy can accelerate recovery and reduce pain in difficult-to-treat shoulder conditions.

Platelet-rich plasma (PRP) is one of the most researched regenerative treatments for rotator cuff injuries. PRP is prepared by drawing a small sample of the patient’s own blood and concentrating the platelet fraction, which is rich in growth factors. When injected into the site of tendon injury, PRP has been shown to promote tendon healing and reduce pain, with evidence supporting its use for both partial tears and tendinopathy⁴. Because PRP is derived entirely from the patient’s own blood, its safety profile is excellent.

Acupuncture is a valuable adjunct therapy for shoulder pain. By stimulating specific points, acupuncture promotes local circulation, reduces muscle tension, and modulates pain signalling, all of which can support recovery alongside regenerative treatments.

For patients with shoulder pain, a comprehensive assessment and individualized treatment plan is available through the sports medicine program at Optimal Wellbeing Clinic in Bedford, Nova Scotia.

References

Maffulli N, Wong J, Almekinders LC. Types and epidemiology of tendinopathy. Clin Sports Med. 2003;22(4):675-692.
Teefey SA, Rubin DA, Middleton WD, Hildebolt CF, Leibold RA, Yamaguchi K. Detection and quantification of rotator cuff tears: comparison of ultrasonographic, magnetic resonance imaging, and arthroscopic findings. J Bone Joint Surg Am. 2004;86(4):708-716.
Coombes BK, Bisset L, Vicenzino B. Efficacy and safety of corticosteroid injections and other injections for management of tendinopathy: a systematic review of randomised controlled trials. Lancet. 2010;376(9754):1751-1767.
Randelli P, Arrigoni P, Ragone V, Aliprandi A, Cabitza P. Platelet rich plasma in arthroscopic rotator cuff repair: a prospective RCT study, 2-year follow-up. J Shoulder Elbow Surg. 2011;20(4):518-528.