Bursitis of the foot is a painful condition occurring when the small fluid-filled sacs near the joints become inflamed. These structures, called bursae, function as cushions to reduce friction between bones, tendons, and muscles. Because the feet constantly bear weight and endure repetitive friction, they are highly susceptible to this inflammatory response, leading to localized pain and mobility issues.
Defining Bursitis in the Foot
A bursa is a thin, slippery sac filled with synovial fluid that acts as a gliding surface to facilitate movement and protect soft tissues. When this sac becomes irritated, its lining produces excess fluid, causing the bursa to swell. This swelling is known as bursitis, and the resulting inflammation leads to increased pressure on surrounding structures, which causes discomfort.
The foot contains numerous bursae, but certain locations are commonly affected due to mechanical stress. Retrocalcaneal bursitis occurs at the back of the heel near the Achilles tendon insertion point. Intermetatarsal bursitis involves the sacs between the long bones of the foot, often mimicking nerve compression symptoms. Bursitis can also develop over bony prominences, such as near a bunion joint at the base of the big toe, where friction from footwear is highest.
Primary symptoms include localized pain and tenderness, which often worsens with movement or pressure. The inflamed site typically presents with noticeable swelling and may feel warm or appear red. Patients frequently experience stiffness and a deep aching sensation that can make walking and wearing shoes difficult.
Factors Contributing to Foot Bursitis
The primary mechanism leading to bursitis is chronic mechanical stress and excessive friction. Repetitive motions, such as long-distance running or standing for prolonged periods, place constant pressure on the foot’s cushioning structures. This sustained overuse irritates the bursal sac, leading to inflammation.
Improper footwear is a major external factor contributing to this condition. Shoes that are too tight, particularly in the toe box, compress the forefoot and increase pressure on the intermetatarsal bursae. High-heeled shoes also shift the body’s weight forward, placing strain on the ball of the foot and increasing friction.
A sudden, direct trauma, like stepping on a sharp object or a direct impact during a sport, can also initiate inflammation in a previously healthy bursa. Foot deformities, such as a bunion or a heel spur, alter walking biomechanics and create abnormal friction points. These structural issues force adjacent bursae to work harder, making them prone to swelling.
Underlying systemic conditions can also predispose an individual to foot bursitis. Inflammatory diseases, including rheumatoid arthritis, cause widespread joint and soft tissue inflammation that can target the bursae. Metabolic disorders, such as gout, involve the deposition of uric acid crystals, which can directly irritate and inflame the bursal sacs.
Treatment and Management Options
Initial management focuses on conservative methods aimed at reducing inflammation and relieving mechanical stress. The R.I.C.E. protocol—Rest, Ice, Compression, and Elevation—is the standard first step to decrease swelling and pain. Resting the affected foot by avoiding aggravating activities allows the bursa to calm down.
Applying ice to the inflamed area for twenty-minute intervals multiple times daily helps constrict blood vessels and minimizes swelling. Over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs), like ibuprofen or naproxen, are recommended to manage pain and target the underlying inflammatory response. Changing to supportive, well-fitting shoes with a wider toe box helps eliminate external pressure.
If conservative measures fail, medical interventions may be necessary. A physician confirms the diagnosis through a physical examination, potentially utilizing imaging like an ultrasound to visualize the swollen bursa or an X-ray to rule out bone abnormalities. For persistent, severe pain, a corticosteroid injection can be administered directly into the bursa to deliver a potent anti-inflammatory agent.
Physical therapy is prescribed to address contributing biomechanical factors and improve foot function. Specific stretching exercises, such as calf stretches, can relieve tension on the Achilles tendon, decreasing pressure on the retrocalcaneal bursa. Custom-molded orthotics or shoe inserts may be used to correct abnormal foot mechanics and redistribute pressure.
Surgical intervention, known as a bursectomy, is reserved for chronic cases where pain remains debilitating despite other treatments. During this procedure, the inflamed bursa is surgically removed to eliminate the source of pain. This option is considered only after six months or more of unsuccessful conservative care.