Can a blood clot in the leg cause involuntary muscle movements in the leg and ankle pain?

It's possible. As poor venous outflow from the muscles in the lower(distal) leg due to a blood clot(DVT) could lead to spasms, but it's not the most common symptom. The swelling often associated can lead to ankle pain.

Related Questions

Is pain in the leg caused by blood clots worse with movement or non movement or does it vary?

Worse with movement. I am not quite clear on your question, but if you are asking about pain after a blood clot, and worse with or without movement, pain is usually increased w/ movement. If you are worried about having a blood clot, you should go to the er, especially since you mentioned "breathless" in your conditions and this could represent a complication of a blood clot, a pulmonary embolism which can be fatal. Read more...
DVT. Deep vein thromboses of the lower extremity could present with any of those scenarios. There is usually a notable swelling of the lower extremity. Read more...

What distinguishes a blood clot in the leg from a pulled muscle?

Get a Dr. to examine. First, have a dr. Examine you, and usually that is all you would need. Definative proof would obtained by getting a vascular study such as a venous duplex doppler study. Read more...