Calf Muscle

Hi, I am after advise on the best way to build my calf muscle following on from an operation on my foot. basically I was on crutches for around twenty weeks due to the operation then an infection in the foot. my left calf muscle measures 32cm and my right measures 37.5cm and is noticeably different in size. the strength in the smaller calf is not very good and I would struggle to do any exercise I see on the internet for a normal calf muscle (my right one for example) I would like to know the best was to start rebuilding/exercising just my left calf muscle.
Thanks
Stu

I would start with something as simple as walking, then add in some hill walking (the down as important as the up) and stationary cycling. Once your basic strength comes back you can think about specific exercises.

You progress from easy to hard as long as there is no pain. You can go from sitting heel raises with longer holds to adding weight to progression to standing with 2 legs to 1 leg. That can further be progressed by standing with the balls of your feet resting on a step, dropping your heels drop below the level of the step then use your calves to push up on your tip toes.
There are many machines in gyms that can facilitate this by increasing weight. You can ride a stationary bike pushing with the balls of your feet.
Remember that the strongest leg will always dominate if you are doing strengthening using 2 legs.
Unfortunately the girth of calf muscles takes a while to increase but you should notice the ability to do more with time, indicating strength return