Diagnosis
Diagnosis is made by clinical history; typically people say it feels like being kicked or shot behind the ankle. Upon examination a gap may be felt just above the heel unless swelling has filled the gap and the Simmonds' test (aka Thompson test) will be positive; squeezing the calf muscles of the affected side while the patient lies prone, face down, with his feet hanging loose results in no movement (no passive plantarflexion) of the foot, while movement is expected with an intact Achilles tendon and should be observable upon manipulation of the uninvolved calf. Walking will usually be severely impaired, as the patient will be unable to step off the ground using the injured leg. The patient will also be unable to stand up on the toes of that leg, and pointing the foot downward (plantarflexion) will be impaired. Pain may be severe and swelling is common.
An O'Brien test can also be performed which entails placing a sterile needle through the skin and into the tendon. If the needle hub moves in the opposite direction of the tendon and the same direction as the toes when the foot is moved up and down then the tendon is at least partially intact.
Sometimes an ultrasound scan may be required to clarify or confirm the diagnosis. MRI can also be used to confirm the diagnosis.
Read more about this topic: Achilles Tendon Rupture