The Achilles tendon is a rope-like structure that runs across the back of the ankle, connecting the calf muscle to the heel.  It provides most of the power when walking, running, and jumping.  

A sudden, sharp pain after jumping or stumbling is often the first sign of an Achilles tendon rupture.  Swelling and bruising will occur over the next few days. 

If is still possible to stand and walk on a ruptured Achilles tendon but it often feels weak or unstable and tends to hurt.  

With no treatment, these do not tend to heal well and a limp with weakness is common.  Recognizing the problem sooner rather than later can improve the results.  Sometimes a boot or cast is effective, other times surgery is recommended. 

If you are worried you may have ruptured your Achilles tendon, you should get it evaluated to be sure.