Diagnosis of Achilles tendonitis, also sometimes called Achilles tendinitis, usually involves taking a patient history, and performing a physical examination and imaging tests (e.g., x-ray, ultrasound). Patient history includes the following:
- History of prior pain or weakness in the lower leg
- History of recreational activity
- Recent changes in activity level, footwear, or training duration or surface
Physical examination involves palpating (i.e., feeling with the fingers) the lower leg for tenderness, swelling, nodules, warmth, and decrease in mass (atrophy). The doctor also measures active and passive range of motion of the knees, ankles, and feet, and determines the resting alignment of the ankles and feet.
A Thompson test is performed to detect rupture of the Achilles tendon. In this test, the patient lies face downward on the examining table with bent knees and the doctor squeezes the back of the lower leg (calf). If the Achilles tendon is at least partially intact, this test causes the foot to flex.
Imaging tests that may be used to help diagnose Achilles tendonitis include x-ray, ultrasound, and magnetic resonance imaging (MRI scan). X-rays cannot conclusively diagnose the condition, but they may be used to detect soft tissue swelling and heel bone calcifications (i.e., calcium deposits) or fractures.
Ultrasound may be used to detect thickening of the Achilles tendon. MRI scan can be used to detect partial tendon rupture and degenerative tendon changes.