Immediately
after week 12, I started physical therapy, which I continued for 27 more sessions (three times per week, one hour each time). The first day was the hardest, as I was instructed to remove the boot and take my first steps without it in more than three months. Needless to say, I limped considerably, with a flat footed gait, as if I still had the boot on.
Little by little, as the tendon gained flexibility and strength, the limp would diminish (although to this day, six months after surgery, I still limp immediately after waking up and when I don’t have a shoe on). After the first week, I started wearing a shoe around the house instead of the boot, and after about ten days, I started wearing the shoe outside too. My therapist said that if I was already wearing the shoe and felt comfortable there was no need to go back to the boot (major milestone!...
no more boot entering week 14 post-op).
Something I observed during therapy is that the progress is very fast in the first two weeks, and then it gets slower afterwards. This is only normal, since after been immobilized for such a long time, the initial excercises have a big impact. In order to keep improving, it is necessary to keep the discipline and increasing the frequency/weight of the excercises.
I always started my therapy with 10 minutes on the
stationary bike. This served the purpose of loosening up the tendon and stretching it a little bit, making the following excercises easier. Remember, you're not doing cardio, so don't try to pedal too fast. I was doing around 40 RPM, trying not to put too much pressure in the tendon.

After the bike, I usually did the
Biodex Dynamometer (see picture to the left, click to enlarge), for
passive range of motion (PROM) excercises (15 minutes per session).
Basically, I sat down in the machine with my right (injured) leg extended, while the therapist adjusted the seat and strapped my foot to a metal platform that would move slowly back and forth, generating
plantarfexion and
dorsiflexion. Since this is a
PROM excercise, it is the machine that does the work, not you.
The idea is to progressively increase both plantarflexion and dorsiflexion angles until a normal range of motion is achieved (getting there took me about three weeks). After that, I used the same machine for active range of motion exercises, meaning that this time I had to move the foot myself. The machine can be set up at different levels of resistence, to make movement harder each time.
One of the simplest and
most important exercises you can do is using the Thera-Band bands. These bands come in different colors, each of them representing a different resistence level. I started off with the green, and then moved to the blue (the yellow is softer and usually recommended when you are just starting therapy). You can see the bands below:

Basically, what you will do with these bands is a group of four excercises called "Resisted Ankle Strengthening", encompassing plantarflexion, dorsiflexion, inversion, and eversion. The excercises are fairly simple and you can see how to do them in this excellent video (you need to Quicktime to view them):
Another excercise that I found very helpful is the Achilles stretching using the ProStretch (see below):


The ProStretch is a round-shaped accessory used to stretch your calf muscles and Achilles tendon. Basically you position your foot on the ProStretch and then roll it backwards (making your toes point upwards). If you keep your leg straight, you will be stretching your calf muscles.
If you do what I described before, but bend your knee a little bit until you feel a light pull on the Achilles, you will be stretching the tendon. That is the idea. I initially did three repetitions of 15 seconds each, and now I do five repetitions (I purchased the ProStretch to use at home every day).
I also did proprioception excercises. Proprioception is "the process by which the body can vary muscle contraction in immediate response to incoming information regarding external forces". Basically, I was instructed to stand on one foot for 30 seconds at a time on top of one of these special Thera-Band cushions:


At first, I used the
green one (more firm), and once I felt comfortable I moved to the
blue one . With this excercise the idea is to re-train your muscles to "remember" how to react when you slightly lose balance. This is very important in order to regain confidence when starting to walk again.