Re: rowing exersize
Simon, if you think of your ankle's tendons, sinews, muscles as connecting to your leg and into your body, then you will be able to benefit from a lot of the leg-straightening exercises seen in Pilates or ballet. Flexing is clearly difficult for you now since the range of motion is not large enough to enable you to do rowing well. Straightening, which means both a twist out at the buttocks and knees and ankle, and a pointing of the toes (the top of the foot is curved as much as you can) and stretching of the back of the knee, will help to increase the range of motion. In that same position try flexing the ankle as much as you can, slowly. Although I said twist, the stretch is linear, the twist is only for alignment.