Shoulder Tendonitis: Symptoms, Types, Causes and Treatment

Shoulder tendonitis is one of the most common causes of shoulder pain, significantly impacting daily life for many people. Whether it appears suddenly or develops over time, this condition can limit movement, disrupt sleep, and make simple tasks challenging. Understanding its symptoms, different forms, underlying causes, and the latest evidence-based treatments is crucial to managing and overcoming shoulder tendonitis. In this comprehensive guide, we'll walk through the key aspects of shoulder tendonitis, so you can better recognize, prevent, and address this debilitating condition.

Symptoms of Shoulder Tendonitis

Shoulder tendonitis manifests in ways that can be both mild and severe, sometimes creeping in subtly before escalating. Recognizing the symptoms early can lead to more effective interventions and a quicker return to normal activities.

Symptom	Description	Onset	Source
Pain	Localized at tendon/shoulder	Gradual/severe	1 5 6
Stiffness	Reduced range of motion	Sudden/Chronic	1 3 5
Weakness	Difficulty lifting arm	Progressive	1 5
Swelling	Inflammation near the tendon	Acute/Chronic	1 4

Table 1: Key Symptoms

Understanding the Symptoms

Shoulder tendonitis often starts with mild discomfort at the site of the tendon, which can quickly progress to intense pain, especially with movement or pressure 1. Pain may be present at rest but typically worsens with activities such as lifting or reaching overhead. For many, the pain can suddenly intensify, particularly during the resorptive phase of calcific tendonitis, when an inflammatory response occurs 3 4.

Stiffness and Loss of Motion

A hallmark of shoulder tendonitis is the progressive loss of shoulder mobility. Stiffness tends to be worse in the morning or after periods of inactivity, making it difficult to perform routine tasks or even dress oneself 1 5. Complete loss of active abduction—lifting the arm sideways away from the body—can occur in severe cases, especially if there is an associated tendon tear 5.

Weakness and Functional Limitation

As the condition progresses, people often notice weakness in the affected arm. This may manifest as difficulty lifting objects, combing hair, or reaching overhead. In some cases, shoulder tendonitis can lead to compensatory movements and further strain on surrounding muscles 1 5.

Swelling and Local Inflammation

Acute inflammation can cause noticeable swelling and tenderness around the shoulder joint. This is especially true during the resorptive phase of calcific tendonitis when the body mounts an aggressive inflammatory response to resorb calcium deposits 3 4.

Types of Shoulder Tendonitis

Not all shoulder tendonitis is the same. Differences in underlying pathology, tendon involvement, and the presence or absence of calcification mean that shoulder tendonitis encompasses several distinct types, each with unique features and treatment considerations.

Type	Main Features	Patient Profile	Source
Non-calcific	Inflammation, no calcium	All ages, active/older	2 3 5
Calcific	Calcium deposits in tendon	30–60 yrs, women>men	2 3 4 6 7
Supraspinatus	Affects supraspinatus tendon	Overhead activities	5
Infraspinatus/Teres	Rare, affects other RC tendons	Middle-aged adults	7

Table 2: Main Types of Shoulder Tendonitis

Non-calcific (Classic) Tendonitis

This is the most common type, often related to repetitive use, incorrect posture, or age-related degeneration. It involves inflammation of the rotator cuff tendons without any calcium deposition. The supraspinatus tendon is most frequently affected, but any rotator cuff tendon can be involved 2 5.

Calcific Tendonitis

Calcific tendonitis is characterized by the deposition of calcium salts, usually hydroxyapatite, within the rotator cuff tendons—most often the supraspinatus 2 3 4 6. This type is more common in women aged 30–60 and can be extremely painful during the resorptive phase, when the body tries to clear the calcium deposits 3 4 6 7. Calcific tendonitis goes through formative (often asymptomatic) and resorptive (painful) phases 3.

Supraspinatus Tendonitis

Focusing specifically on the supraspinatus muscle, this type is strongly associated with repetitive overhead activities and impingement syndrome. It may progress to partial or full-thickness tears if untreated 5.

Infraspinatus and Teres Minor Tendonitis

Less commonly, calcific deposits or inflammation can affect the infraspinatus or teres minor tendons. These cases are rarer and may present with slightly different patterns of pain and dysfunction but share the same overarching mechanisms 7.

Causes of Shoulder Tendonitis

Shoulder tendonitis is multifactorial, often resulting from a blend of lifestyle, anatomical, and physiological factors. Understanding the root causes provides insight into prevention and management.

Cause	Mechanism	Risk Group	Source
Overuse/Repetition	Microtrauma from repeated motion	Athletes, workers	1 2 5
Aging/Degeneration	Wear and tear, reduced healing	Older adults	5 6
Poor Posture	Altered biomechanics	Sedentary/office	1 7
Calcium Deposition	Abnormal mineralization	30–60 yrs, women	3 4 6 7
Autoimmune/Other	Systemic disease, rare	Variable	1

Table 3: Primary Causes of Shoulder Tendonitis

Overuse and Repetitive Strain

The most common cause is overuse—repetitive overhead activities (like sports, manual labor, or even household chores) lead to microtrauma and inflammation of the tendons 1 2 5. Poor conditioning and lack of proper warm-up before exercise can increase the risk 1.

Aging and Degeneration

As we age, tendons lose their elasticity and blood supply, making them more prone to injury and slower to heal. Degenerative changes and chronic wear and tear are significant contributors to tendonitis in older adults 5 6.

Poor Posture and Biomechanics

Sedentary lifestyles and incorrect posture, especially among office workers, can alter shoulder mechanics and increase the risk of tendon overload 1 7. Ergonomic risk factors play a significant role in both classic and calcific tendonitis.

Calcium Deposition and Calcific Tendonitis

In calcific tendonitis, abnormal mineralization occurs within the rotator cuff tendons. The exact mechanism is not fully understood, but involves transformation of tendon cells into chondrocyte-like cells that deposit calcium, potentially triggered by microtrauma, hypoxia, or tendon stem cell activity 3 4. These calcium deposits can cause severe inflammation—particularly when the body attempts to resorb them 3 4 6.

Autoimmune and Rare Causes

In rare cases, systemic conditions such as autoimmune hepatitis can initially manifest as tendonitis, illustrating the importance of considering underlying disease in persistent or atypical cases 1.

Treatment of Shoulder Tendonitis

Treatment for shoulder tendonitis has evolved considerably, with most cases responding well to conservative measures. For chronic, severe, or calcific cases, more advanced interventions—including minimally invasive procedures—are available.

Treatment	Purpose	When Used	Source
Rest & Activity Mod.	Reduce stress, aid healing	First-line, all cases	1 2 12
NSAIDs/Analgesics	Manage pain/inflammation	Acute/chronic symptoms	1 2 12
Physical Therapy	Restore function/strength	Essential, all stages	1 5 9 12
Corticosteroid Inj.	Reduce severe inflammation	Persistent/severe cases	1 2 12
ESWT	Break up calcifications	Chronic calcific cases	2 8 9 10 11
Needling/Aspiration	Remove calcium deposits	Symptomatic calcific	3 8 9
Surgery	Remove deposits/repair tears	Refractory cases	2 3 9 12

Table 4: Key Treatment Modalities

Conservative Management: The Foundation

• Rest and Activity Modification: Avoiding aggravating activities gives the tendon time to heal and reduces inflammation 1 2 12.
• NSAIDs and Analgesics: Nonsteroidal anti-inflammatory drugs help manage pain and reduce inflammation; topical creams and oral medications are commonly used 1 2 12.
• Physical Therapy: Targeted exercises restore strength and flexibility, reduce stiffness, and lower the risk of recurrence. Rehabilitation is essential both after injury and post-operatively 1 5 9 12.
• Patient Education: Teaching proper posture, ergonomics, and gradual return to activity is vital for long-term success 5.

Corticosteroid Injections

For persistent or severe inflammation, subacromial corticosteroid injections can provide rapid relief. However, these are usually reserved for cases not responding to first-line treatments due to potential side effects with repeated use 1 2 12.

Advanced and Minimally Invasive Techniques

Extracorporeal Shock Wave Therapy (ESWT)

• Mechanism: Uses focused sound waves to break up calcium deposits and stimulate healing.
• Indications: Particularly effective for chronic calcific tendonitis and in patients not responding to conservative management 2 8 9 10 11.
• Effectiveness: Multiple randomized controlled trials show ESWT reduces pain and improves function mid-term, with minimal side effects. High-energy protocols and combination with ultrasound-guided needling yield better results 8 10.
• Limitations: Not universally effective; optimal dosing and long-term benefits still under investigation 2 10.

Ultrasound-Guided Needling and Aspiration

Minimally invasive aspiration of calcium deposits under ultrasound guidance can rapidly relieve pain and speed recovery in calcific tendonitis. When combined with ESWT, outcomes are even better, reducing the need for surgery 3 8 9.

Surgical Intervention

Reserved for refractory cases or when there is a large, painful calcific deposit or associated rotator cuff tear. Arthroscopic removal of deposits is preferred, and complete removal of the deposit is often unnecessary, as natural resorption can occur 2 3 9 12.

Rehabilitation and Long-Term Care

Rehabilitation continues to be a cornerstone of recovery, focusing on restoring shoulder mechanics, preventing stiffness, and educating patients about recurrence prevention strategies 5 9.

Conclusion

Shoulder tendonitis is a multifaceted condition affecting people of all ages and activity levels. Prompt recognition and a clear understanding of its types, causes, and treatments can dramatically improve outcomes and quality of life.

Main Points:

• Symptoms include pain, stiffness, weakness, and sometimes swelling, often worsening with activity or during certain disease phases.
• Types include non-calcific, calcific, supraspinatus, and less commonly, infraspinatus/teres minor tendonitis.
• Causes range from overuse and age-related degeneration to poor posture, abnormal calcium deposition, and rarely, systemic disease.
• Treatment is usually conservative, involving rest, NSAIDs, and physical therapy; advanced interventions like ESWT, needling, and surgery are reserved for persistent or severe cases.

Empowering yourself with knowledge and actively engaging in your care plan can help you overcome shoulder tendonitis and return to the activities you love. If symptoms persist or worsen, consult a healthcare professional to explore advanced treatment options tailored to your needs.