Shin splints is a generic term used to describe any pain felt between the knee and the ankle, but what exactly is it and how does it occur?
True shin splints is caused by a pulling of the leg muscles on the shin bone. It is felt as a dull ache in the shin that becomes intense on running or walking but that is relieved by rest. The shin is tender to touch but circulation is healthy and there is no muscle weakness, no pins and needles and no numbness in the leg.
When the muscles of the calf and the shin are tight they transmit more force than they absorb. This results in the bone suffering great stress as the muscles pull on their attachment points creating pain. This can be so severe that it actually causes microscopic fractures of the bone itself!
All muscles of the lower leg are concerned with movement of the foot and ankle. The group of muscles attaching at the front (shin) are concerned with bending the foot upwards away from the floor. The group attaching at the back (calf) is concerned with bending the foot downwards towards the floor. Both the calf and shin muscles also turn the foot inwards, supporting the instep.
Anything causing these muscles to pull more strongly on their attachments causes shin splints pain.
Preventing the development of this muscle tension is vital to avoiding the development of shin splints.
When the calf muscles at the back are very tight, the tension pulls the foot downwards rapidly when running. This is often felt (and heard) as a slapping of the foot on the road. The shin muscles at the front oppose the calf muscles at the back. They must work hard to slow down this rapid downward movement of the foot. They become over-worked and pull on the bone at the front creating shin splints pain here.
Not stretching or stretching in-effectively is an obvious reason for the presence of muscle tension and the most common cause of shin splints by far.
However, there may be other biomechanical reasons for the muscles becoming so tense and I have outlined a few examples below.
- Stiffness in the ankle or foot joints results in the muscles having to work harder as they must overcome the stiffness to produce normal foot movement and this will result in increased muscle tension in the shin and calf.
- Ankle sprains change the stability of the ankle joint. The shin and calf muscles then need to be used more to re-stabilise the joint increasing the tension in these muscles.
- Also, over pronation (rolling inwards) in the foot when walking and running will cause the calf and shin muscles to work together to support the instep, over loading them and leading to tension.
- Either a leg length difference or torsion of the pelvis may cause more weight to be placed on one leg than the other leading to over-development of the muscles on that side.
These are just a few examples of what an Osteopath may discover in a patient with shin splints, the real picture may be more complex. Simply stretching correctly after exercise is often enough to avoid this painful condition. However, if you suffer from shin splints then it is a good idea to see your osteopath for an assessment and treatment. The assessment will provide the information that you need to avoid a reoccurrence after the treatment has helped the injury to heal.
Geoffrey Hogan (M.Ost)