The designation of shin splints tends to be used for any pain causing factor of the shin or lower leg area. We will refer to these as general shin splints and discuss them later. True shin splints are otherwise known as medial tibial stress syndrome or periostitis and are the result of swelling or inflammation of the periostium of the tibia. The periostium is a fibrous sheath or membrane that covers bones. It is attached directly to the bone and contains all of the nerves and blood vessels that nourish the bone.
In general shin splints refer to an injury with pain at, around or behind the shin. This injury can be any number of things such as:
- An inflamed or injured lower leg muscle
- A hairline or stress fracture of one of the lower leg bones
- Flat feet - a flattened arch of your foot allowing the middle part of your foot to touch the ground
- High arches - when the arch of your foot is exceptionally high and sometimes rigid
- Overpronation (the foot turning inward too much) or oversupination (the foot turning outward too much)
- Irritation of the posterior peroneal tendon
- Damage to the soft tissue of the lower leg resulting in swelling or inflammation
- A build up of edema exerting pressure on the shin or surrounding tissue
Overexerting the shin area of the body is quite easy since it takes massive impacts every time your foot contacts the ground. The stress from that impact transmits from the foot, through the ankle and into the lower leg. Your foot and ankle are both rather flexible anatomical components. All of the bones and joints of the foot make it a fantastic shock absorber. But there is still a great deal of force that makes it through the ankle. The shin is the first rather rigid skeletal component to absorb all that stress. And since it is rigid it does absorb a lot of it without passing it on up the body.
And if your body mechanics are messed up then things have compounded for the worse. In a typical step your shin, ankle and foot go through a complicated motion of pronating (rotating inwards) so you contact on the heel of your foot then along the side to the ball just behind your toes. As your foot leaves the ground it supinates (rolls outwards). If that gets messed up, or you have more weight forwards or backwards so you are not balanced and your lower legs have to compensate for it then it is easy to overload the shin, especially where it connects with the ankle. And that is not even getting into the complexities of shod versus barefoot body mechanics or doing something other than walking and running (like jumping, stopping or kicking).
Though there is such a thing as "true" shin splints one of the main reasons the term shin splints has become a catch all for a number of lower leg injuries is because they are often treated the same. Treating shin splints can often be done at home with ice and rest. You can also have a full recovery from shin splints, regardless of the type, without any lingering impact on your activity.
