Insertional Achilles Tendinitis

The Achilles tendon extends from the calf muscles down to the heel bone, known as the calcaneus. Insertional Achilles tendinitis occurs when the lower portion of the tendon, where it inserts into the heel bone, becomes inflamed or degenerates due to repetitive stress and overuse.

Unlike non-insertional Achilles tendinitis, which affects the middle section of the tendon, insertional Achilles tendinitis specifically involves the attachment point at the heel. Over time, chronic irritation may lead to thickening of the tendon, degeneration of tendon fibers, and the formation of bone spurs at the back of the heel.

Although the condition is often referred to as “tendinitis,” many patients actually develop tendinosis, a degenerative process involving microscopic damage to the tendon rather than active inflammation.

Another condition that is closely related to insertional Achilles tendinitis is retrocalcaneal bursitis. The bursa sac that cushions your Achilles tendon from the back of your heel bone (also known as a Haglund’s deformity) can become swollen and inflamed, make the back of your heel bone very sensitive to the touch. This can make it difficult to wear closed heel shoes.

Insertional Achilles tendinitis typically develops gradually rather than resulting from a single injury. Repeated stress on the tendon can cause small areas of damage that accumulate over time. Several factors that may contribute to the development of this condition include:

Overuse and repetitive activity

Activities that place repeated strain on the Achilles tendon are among the most common causes. Running, hiking, walking long distances, jumping sports, and activities that require frequent pushing off the foot can increase stress on the tendon attachment. A sudden increase in training intensity, duration, or frequency can also contribute to the condition.

Tight calf muscles

Limited flexibility in the calf muscles can increase tension on the Achilles tendon during walking and exercise. This added strain may place excessive stress on the tendon where it attaches to the heel bone.

Foot structure and biomechanics

Certain foot types can increase the risk of insertional Achilles tendinitis. Flat feet, high arches, and abnormal walking patterns may alter the forces placed on the Achilles tendon and contribute to irritation over time.

Bone spurs

Some individuals develop bony growths on the back of the heel bone. These bone spurs can rub against the skin on the back of the heel, creating friction and irritation that leads to pain and inflammation.

Age-related tendon changes

As people age, tendons naturally become less flexible and less capable of repairing microscopic damage. This makes middle-aged and older adults more susceptible to Achilles tendon problems.

Excess body weight

Carrying additional body weight increases the load placed on the Achilles tendon during everyday activities, potentially accelerating wear and tear.

Improper footwear

Shoes that lack adequate support or place excessive pressure on the back of the heel may contribute to irritation of the tendon insertion site.

The most common symptom is pain at the back of the heel where the Achilles tendon attaches to the heel bone. The pain may initially occur only during exercise but can eventually become noticeable during routine daily activities.

Other common symptoms include:

• Tenderness at the back of the heel
• Swelling around the tendon insertion
• Stiffness in the ankle and heel
• Pain when walking uphill or climbing stairs
• Increased discomfort after physical activity
• Difficulty pushing off the foot while walking
• Reduced ankle flexibility
• Thickening of the tendon
• A noticeable bump at the back of the heel

Many patients report that symptoms are especially severe when taking their first steps in the morning or after prolonged periods of rest. As the tendon warms up with activity, discomfort may temporarily improve before worsening again later in the day.

A diagnosis begins with a detailed evaluation by an orthopedic specialist. Your physician will review your symptoms, medical history, activity level, and any previous foot or ankle injuries.

During the physical examination, your Orthopedic Associates of Northern California clinician will evaluate:

• The location of pain and tenderness
• Swelling around the tendon
• Calf muscle flexibility
• Ankle range of motion
• Tendon strength
• Walking and gait mechanics

The examination helps distinguish insertional Achilles tendinitis from other causes of heel pain, such as bursitis, plantar fasciitis, or stress fractures.

Imaging studies are often used to confirm the diagnosis and assess the severity of the condition. Imaging studies may include:

• X-rays: X-rays can identify bone spurs, calcifications within the tendon, and other abnormalities involving the heel bone.
• Ultrasound: ultrasound imaging allows physicians to evaluate the tendon in real time and assess tendon thickening, inflammation, and structural changes.
• Magnetic resonance imaging (MRI): MRI provides detailed images of the Achilles tendon and surrounding tissues. An MRI may be recommended when significant tendon degeneration, partial tearing, or other complex issues are suspected.

Early diagnosis can help prevent progression of tendon damage and allow patients to address symptoms before they significantly affect mobility and quality of life. If you are experiencing persistent pain at the back of your heel, the orthopedic specialists at Orthopedic Associates of Northern California in Chico, California can provide a comprehensive evaluation and help determine the cause of your symptoms. Take the first step. Call Orthopedic Associates of Northern California to schedule a consultation.