Shoulder Tendonitis (Tendinopathy): causes, assessment and recovery
Shoulder tendonitis — more accurately called rotator cuff tendinopathy — is a common cause of lateral shoulder pain and weakness.
Quick facts
Also called: rotator cuff tendinopathy, supraspinatus tendinopathy.
Typical symptoms: pain with overhead activity; pain at night; weakness; difficulty with lifting or reaching.
Usual course: many people improve with structured, progressive loading and self‑management over 6–12 weeks; some require longer rehab or specialist review.
When to seek help: severe or progressive weakness, sudden loss of movement after injury, or symptoms that don’t improve after 6–12 weeks of guided rehab.
What is tendinopathy?
Tendons attach muscle to bone and transmit force. Tendinopathy describes a spectrum from reactive inflammation to degenerative tendon change caused by overload, poor mechanics, or age‑related tendon vulnerability. In the shoulder the supraspinatus tendon is most commonly affected, though other rotator cuff tendons can be involved. Clinicians often use “tendinopathy” rather than “tendinitis” to reflect both inflammatory and degenerative processes.
How tendonitis differs from related shoulder problems
Shoulder impingement: mechanical compression can cause or worsen tendon symptoms.
Rotator cuff tear: structural tendon disruption; tendinopathy can exist without a tear but may predispose to one.
Frozen shoulder (adhesive capsulitis): global stiffness and restricted passive range; tendinopathy usually causes pain with specific movements.
Nerve pain: neuropathic features (burning, tingling, shooting) suggest nerve involvement rather than isolated tendon pathology.
Causes and risk factors
Overuse (repetitive overhead work or sport).
Sudden increase in load (training spikes, return to activity).
Poor shoulder mechanics (scapular dyskinesis, weak rotator cuff or scapular stabilisers).
Age-related tendon changes.
Posture and thoracic stiffness.
Systemic factors (e.g., diabetes, smoking) that impair tendon healing.
Red flags — contact me urgently if you have
Sudden, severe loss of active elevation or external rotation (possible large tear).Rapidly worsening weakness despite treatment.Signs of infection (fever, severe local redness, systemic symptoms).New neurological symptoms such as progressive numbness or shooting pain down the arm.
Frequently asked questions
How long will it take to get better?
Most people improve within 6–12 weeks with a structured rehab plan; returning to high‑demand sport can take longer.
Do I need an MRI?
Not usually at first. I reserve imaging for suspected tears, severe weakness, or symptoms that don’t improve after appropriate rehab.
Are steroid injections safe?
They can provide short‑term pain relief but do not fix the underlying tendon problem. Because I focus on long‑term recovery through exercise and load management, I do not recommend injections as a routine treatment.
Can I keep exercising?
Yes — but modify activities and follow a graded loading programme. Avoid movements that cause sharp pain.
What’s the difference between tendinitis and tendinosis?
“Tendinitis” implies inflammation; “tendinosis” refers to degenerative changes. “Tendinopathy” covers both and is the term I use clinically.
A patient story
Sarah-office worker and weekend tennis player
Sarah had three months of lateral shoulder pain that woke her at night and stopped her serving.
I assessed her, found weak scapular stabilisers and a recent training spike. We worked through a 10‑week progressive rehab plan focused on posture, scapular control and progressive rotator cuff loading. By week 8 she returned to light tennis; at 12 weeks she was pain‑free with full strength and no night pain. She now does maintenance strengthening twice weekly and manages her training load.