Tight calf muscles that won't get longer

Hi,

I have ehlers-danlos syndrome and all my joints are very bendy but I have tight calf muscles. When I was younger they were worse so I couldn't always put my heals on the floor and they would spasm whenever I tried to walk. Now I can put my heals on the floor and have just enough movement to walk heal toe. However, I would like them to be less tight because they tense up and restrict my walking and I can't do things like squats and lunges because of the restricted movement in my ankles.

I stretch them several times a day and do a variety of different stretches. I can feel it pull but it eases off so I can't get any feeling of stretch. If I try stretching them more they just get too sore.

I have been stretching them since I was a child and have also had serial casting which had no effect. I have had neurological causes ruled out. I saw orthopaedics when I was younger who said that they would consider lengthening the tendons if I stopped being able to stand flat on the floor or if I had too many functional problems. But because of my EDS they would be reluctant to operate on me (and I would probably be too nervous of it worsening my joint stability to have anything done).

They have not got any looser over the past three years or so and stretching them only maintains my current range of movement.

I'd like to know if I can expect them to get any longer, if there is a limit to how much you can stretch a muscle or if there is something that might be preventing them from getting longer.