The ankle is the biggest functional joint within the foot and ankle/lower leg. It makes up the predominant part of the range of motion and allows the foot to be able to acclimatise to being lifted/dorsiflexed and dropped/plantar flexed. This is essential to allowing ground clearance with walking, and also providing some propulsion through the gait phase. Examples where the ankle joint is not functioning ideally can be foot drop and other arthritic type injuries within the ankle. Anterior impingement or blocking in through the front of the ankle is a very common injury that can be caused as part of an arthritic type of process. This is something that is well alleviated with the right balance of orthotic and footwear.