Squat Report: Shins
This month we have been dissecting the shins apart and we are going to look at how the shins act during a squat. Nothing really should be to fancy, and some things might surprisingly pop up. So, let’s dive in and see what comes out.
During dorsiflexion at the distal aspect (furthest from the head) the fibulotalar and tibulotalar joints want to splice open which causes the calcaneofibular joint to “slip” down which causes a sheer at the this joint (it isn’t much maybe 1 mm or less). At the proximal aspect (closest to the head) the fibulotalar joint also wants to “slip”. Also, the tibial plateau wants to rotate in an outward fashion which will force the fibulotalar joint to “pop” out. The muscles around the entire lower leg must fire so these “slips”, “splices” and “pops” are minimal to null. So, the muscles are controlling this downward force on the joints and are trying to keep the joints in place without and dislocation.
During plantarflexion at the distal aspect the fibulotalar and tibulotalar joints are forces together and causes the calcaneofibular joint to “slip” up. At the proximal aspect of the joint the fibulotalar joint is now pushing upward toward the knee because of what is happening at distal aspect. The tibial plateau rotates inward toward the middle of the body. The muscles now have fire yet again not only to keep the bones in place but also lift the body back into a standing position.
This is brief look is what it is only because all the muscles that control this upward, inward and downward, outward movement are all explained in the previous months blog posts when I discussed the feet and ankles, and the proximal “shin” muscles are further explained next month when we look at the knee.
The only two muscles to really consider would be the anterior Tibialus and posterior Tibialus.
Anterior Tibialus primary function is to dorsiflex and invert (pull the foot inward) however, the anterior Tibialus also helps keep the tibia and fibula in place while preforming dorsiflexion and provides stability to the two bones so that the bones don’t pop out of place during plantar flexion.
Posterior Tibialus primary function is for stabilization of the arches and also helps with inversion and helps keep the fibula and tibia stabilized from the forces that are being distributed into the ankles and feet.