Achilles Tendon Enthesopathy
(See also Overview of Foot and Ankle Disorders.)
The cause of Achilles tendon enthesopathy is chronic traction of the Achilles tendon on the calcaneus. Contracted or shortened calf muscles (resulting from a sedentary lifestyle and obesity) and athletic overuse are factors. Enthesopathy may be caused by a spondyloarthropathy. Fluoroquinolone antibiotics increase the risk of Achilles tendinopathy or tendon rupture especially in people over age 60.
Pain at the posterior heel below the top of the shoe counter during ambulation is characteristic. Pain on palpation of the tendon at its insertion in a patient with these symptoms is diagnostic. Manual dorsiflexion of the ankle during palpation usually exacerbates the pain. Recurrent and especially multifocal enthesitis should prompt evaluation (history and examination) for a spondyloarthropathy.
Physical therapy is essential for home exercise programs aimed at calf muscle–stretching techniques, which should be done for about 10 minutes 2 to 3 times a day. The patient can exert pressure posteriorly to stretch the calf muscle while facing a wall at arms’ length, with knees extended and foot dorsiflexed by the patient's body weight. To minimize stress to the Achilles tendon with weight bearing, the patient should move the foot and ankle actively through their range of motion for about 1 minute when rising after extended periods of rest. Night splints may also be prescribed to provide passive stretch during sleep and help prevent contractures.
Heel lifts should be used temporarily to decrease tendon stress during weight bearing and relieve pain. Even if the pain is only in one heel, heel lifts should be used bilaterally to prevent gait disturbance and possible secondary (compensatory) hip and or low back pain.
For more recalcitrant forms of Achilles tendon enthesopathy, extracorporeal pulse activation therapy (EPAT) should be considered. In EPAT, low-frequency pulse waves are delivered locally using a handheld applicator. The pulsed pressure wave is a safe, noninvasive technique that stimulates metabolism and enhances blood circulation, which helps regenerate damaged tissue and accelerate healing.