Those are great.
I even use them on my city shoes it's awesome for the feet and the knees.
I had a serious achilles tendon problem 5 months ago: micro lesions of the tendon. 6 straight weeks with no activity
So my doctor gave me a training program called the Landberg protocol
It's an easy way for rehabilitation and also prevention
Basically you strech the tendon using a step in the gym and you put your feet on it then you put your weight on the heel to feel the calf and the tendon stretch
4 x 10 reps
Now I do it even before warming up as prevention
It rubs the lotion on its skin or else it gets the hose again