I unexpectedly tore my Achilles tendon. I wasn't doing anything strenuous, just walking in my living room. What could have caused this to happen? Was I born with a weak tendon?

The Achilles tendon is a large, strong fibrous cord along the back of your lower leg. It connects the calf muscles to the heel bone (calcaneus). The Achilles tendon helps you point your foot down or rise up on your toes. When you walk, the Achilles helps you push off your foot.

No one is exactly sure why some people spontaneously rupture the Achilles tendon.It can happen even to top athletes. If you overstretch your Achilles tendon, it can tear (rupture). A rupture can be partial or complete. Usually it occurs just above the heel bone, but it can happen anywhere along the tendon.

Other possible causes of Achilles tendon rupture can include overuse, running on hard surfaces, or tight calf muscles. Activities that put you at risk for Achilles rupture are tennis, racquetball, or basketball. Any activity that involves sudden starts and stops can result in tendon rupture.

Sometimes injuries occur from overstretching your Achilles tendon while doing something simple like walking through your living room.