Bursitis Treatment with LLLT/PBMT

What is Bursitis?

Bursitis is the inflammation of a bursa, a small, fluid-filled sac that acts as a cushion between bones and soft tissues, such as muscles, tendons and skin. Bursae reduce friction and allow smooth movement of these structures. When a bursa becomes inflamed, it can cause pain, swelling and limited movement. Bursitis commonly occurs in joints such as the shoulder, elbow, knee and hip, often as a result of overuse or trauma. Chronic bursitis can lead to long-term discomfort and impaired mobility if not treated effectively.

Causes of Bursitis

Several factors contribute to the development of bursitis:

• Repetitive Movements: Continuous motion or pressure on a joint can irritate the bursa, causing inflammation. Activities such as kneeling, lifting, or overhead movements can strain the bursa.
• Overuse: Excessive use of a joint without adequate rest or recovery increases the likelihood of bursitis, especially in athletes or individuals who perform repetitive tasks.
• Trauma or Injury: Direct blows or falls onto a joint can irritate or damage the bursa, leading to inflammation.
• Age-Related Changes: As we age, the bursae become less resilient, making them more susceptible to inflammation.
• Infection: In some cases, bursitis can be caused by an infection, leading to more severe symptoms and requiring immediate medical treatment.

Common Sites Involved

Bursitis can occur in several areas of the body, including:

• Shoulder: The subacromial bursa in the shoulder is commonly affected, especially in individuals performing overhead activities. Read more here.
• Hip: Trochanteric bursitis, affecting the hip, is common in runners or those who frequently engage in side-to-side movements. Read more here. 
• Knee: Various bursae of the knee can become inflamed from activities such as kneeling. Read more here.
• Foot: The bursa located at the bottom of the foot, often near the base of the big toe (Bunion bursitis) or in the heel (retrocalcaneal bursitis), can become inflamed, usually due to pressure from poorly fitted footwear or repetitive stress, such as walking or running. Read more here.
• Heel: The bursa between the heel and the Achilles tendon can become inflamed, often due to excessive pressure from activities such as running. Read more here.

In Many Cases, Bursitis is Secondary to Underlying Tendon Dysfunction

In many cases of bursitis, especially outside purely traumatic or infective causes, the condition is often secondary to underlying mechanical overload, tendon dysfunction, or adjacent soft tissue injury. The bursa acts as a friction-reducing structure between tendons, muscles, and bones. When the underlying tendon is overloaded, degenerated, or mechanically impaired, altered biomechanics cause increased friction, compression, or shear forces across the bursa, which leads to reactive inflammation, resulting in clinical bursitis.

Examples of Bursitis and Associated Tendon Involvement:

• Subacromial Bursitis: Associated with rotator cuff tendons (supraspinatus, infraspinatus, subscapularis).
• Trochanteric Bursitis: Often linked with gluteus medius/minimus tendinopathy.
• Pes Anserine Bursitis: Associated with overload of sartorius, gracilis, and semitendinosus tendons.
• Deep infrapatellar Bursitis: below the kneecap associated with patellar tendinopathy

A key distinction is that olecranon (elbow) bursitis and prepatellar knee bursitis – here tendon injury is not a common primary cause. In most other bursae, especially in chronic cases, bursitis is more likely to be reactive to altered tendon mechanics or muscle imbalance.