In the previous article we learnt the basic mechanism by which the body heals itself after injury. In this article we are going to apply that learning to chart a path to resolving shin pain. This article requires that you have read the article, a deep dive into shin pain.
As discussed in the previous article, there could be 2 reasons why you may be going to your orthopedic for shin pains. These 2 reasons are - 1). Weak arches of the foot 2). Preferring one leg over other for standing. Each can influence the other.
Weak arches and shin pain
The human foot can maintain its shape even after forces up to 10x the body weights have been applied to it. What happens though when this structure fails? Foot is our primary contact with the ground. Any malfunction at the foot precipitates upwards causing pain, injury and disability in the shin, knees, hips and spine.
Our feet pronate slightly as we start bearing our weight on one leg but it quickly returns to the normal arched position. This motion ensures that the most powerful muscles in the legs, namely the calves are loaded appropriately to propel the body forward over the leg. It also disperses forces into the rapidly stretching calves thus protecting the knees and the shin from damage.
When the foot fails to return to the neutrally arched position, or its return is delayed for whatever reason, the ground reaction forces are taken up into the shin bone and the responsibility to propel the body falls on the smaller lateral stabilizers of the ankle, namely fibularis longus, and fibularis brevis. This in turn feeds the pronation thus causing the situation to worsen over time.
This altered function of the foot makes the muscles that oppose pronation (eversion) weak. As a result they may become stretched, tight, and weak (tibialis anterior, and tibialis posterior, Flexor digitorum longus). Such muscles become spastic and can cause debilitating pain on the shin bone.
The calf muscle gets progressively weaker thus the ability of the calf as the primary plantarflexor as well inverter of the foot diminishes. This cannot be a good sign for someone troubled with shin pain.
Bearing weight on one leg while standing
This is slightly more nuanced but since you have read so far, I can safely tell you about this without losing your attention. So here it goes, there are two things that can happen when we prefer one leg over another while standing.
Gluteus medius is strong and tight - In this situation with every step that you take, the hip internally rotates. This alters the way your muscles work while bearing the load of the body as well as when you propel the body. In addition to the eversion at the foot, the primary extensor at the hip is no longer gluteus max, its adductor magnus.
While working with a local soccer team, I saw many players with shin splints also had groin injuries. Is that a co-incidence? Probably not! Myofascial release given to the fibularis muscles, as well as the tibialis posterior, and flexor digitorum longus at half-time used to resolve both groin as well as shin issue. Of course this was a band-aid solution.
Since the gluteus medius is tight, it abducts the hip. The opposite side will be hiked up, possibly externally rotated and adducted.
Gluteus medius is weak,long, and tight - A weak gluteus medius on the weight bearing side is just as bad. In this siuation, the hip hikes up. This hiking up causes the internal obliques, and QL on the weight bearing side to become tight. Which moves the hip into external rotation. Also, as a result of hiking, the hip is adducted on the weight bearing side.
This creates a functional long leg on the opposite side. This leg is abducted, and internally rotated. Because there is not sufficient stimulus of the foot, the arches are weak on this side. This then undergoes the same cycle as described in the weak arches section, leading to a shin splint.
This completes the background that we need in order to test, and implement a regime to correct shin splints. In part 2 of this article we are going to go deeper into bone injury, recovery, and healing.