Ankle mobility is an oft-overlooked weak link, because your ankles and feet help form a stable foundation for stronger, pain-free movement. But how can you tell if your ankle mobility isn't up to par? Try this quick assessment. In this quick knee-to-wall test, first place a strip of masking tape or any other sticky solution that is about 10cm long on the ground, perpendicular against the wall. This tape marks where to place your foot so that the tip of your toes would also be about 10cm from the wall. Make sure your foot is straight and pointed forward, and attempt to make your knee touch the wall without letting your heel come off the ground or your knee deviate from an otherwise straight path. Here's a quick side view:
Try on both ankles. If you can do this without your heel lifting off or your knee collapsing in or shifting out, you've got good ankle mobility, especially for squatting and doing similar leg exercises in the gym. Don't feel bad though, most people actually have poor ankle mobility in one or both ankles. Check out this article and this one to work on it.
Knee to wall test [Strength Physio]