kaian,

You said you've stopped running. Have you had any problem since then? Is it possible that it was more the running than the indoor riding that caused your achilles tendonitis?

If you're pretty sure it was the indoor riding, then Knotted's advice is right on the nose! Vary your position on the bike as much as you are able when you are on the trainer. Stand up, lean one way and then the other (not so much you tip the trainer over! ) Make sure you warm up well before you start pushing. Did you talk about this with your PT? Maybe she/he would have some insight as to what caused the problem. Were there certain exercises you did while in PT that you could start to do now to prevent the problem from occurring? I know what it's like to have to ride indoors in the winter - it gets plenty cold here, too. Plus dark! So I hope you are able to make it work for you.

annie