The foot is an intricate biomechanical design that needs to carry out a lot of movement. Because it is such a intricate structure, there is a lot that can go wrong using it. There are several dysfunctional deviations in the foot which could have an effect on the normal function and trigger problems. Podiatrists regularly make use of foot orthoses, footwear customizations as well as exercises to deal with most of these problems.
There are many deformities with the forefoot that will need to be accommodated in foot orthoses. That is based on the theory of the foot biomechanics which for the feet to be normal that a plantar plane imagined under the ball of the foot is required to be perpendicular to a bisection of the back of the heel bone. There are various deviations which the forefoot could have compared to what is the supposed normal. The inside side of the forefoot may be lower resulting in a deviation that becomes called a forefoot valgus. A forefoot valgus might be the entire forefoot is everted or perhaps it could just be the medial side of the forefoot being plantarflexed. This sort of foot can have important problems about how the foot moves. What exactly these outcomes are depends on how rigid the mid-foot is. When the midfoot is rigid, this forefoot valgus will cause the feet to tilt outwards at the rearfoot creating a high arched foot. If your mid-foot is flexible, then this foot type will simply cause the arch of the foot to distort and flatten the foot posture.
One other kind of foot type is what is known as forefoot varus where the front foot is in an inverted angle compared to that bisection on the hindfoot. This makes a rather flat foot with very little arch at all. There are 2 different types of feet which have this appearance. One of them is known as a proper forefoot varus and is bony in origin. There isn't anything apart from foot orthotics which can be used to improve the posture of the foot. There aren't any exercises or anything else that can be done with this foot type. There is a lot of lousy info on the internet regarding treating this type of flat foot. The type of inverted ball of the foot that looks rather flat is one that is because of a foot type known as forefoot supinatus. This forefoot supinatus is a soft tissue stiffening which props up foot in this placement. As forefoot supinatus is a soft tissue problem, exercises and making the foot more flexible might help this foot type and foot supports generally don't work too well in this foot type. Those that often provide all the bad info on the internet do not know the difference between forefoot varus and forefoot supinatus. Both are linked to "overpronation" of the feet, as well as both will look quite similar but they both have very different causes, so if they have to be dealt with, then they should have totally different treatments.
If you feel you have any kind of of these types of structural problems, it can be quite a great idea to visit a podiatrist.