The Mighty Foot
March 1, 2012
The foot – intricate in it’s construction but able to withstand our bodyweight as well as hundreds of pounds of impact during dynamic movements such as running and jumping. The foot allows for proper movement continuous with the whole body.
28 irregular bones
over 200 ligaments
Without going into pages and pages of anatomy, let’s highlight the major players in the foot.
The ankle and foot contain 26 bones, arranged into the tarsus, metatarsus and phalanges. There are seven tarsal bones. One of the tarsal bones, the talus, is the tarsal bones that articulates with the tibia to form the ankle joint. The calcaneus is the largest of the tarsal bones and forms the heel. The metatarsus, or sole of the foot, is composed of five metatarsal bones. These bones are numbered 1-5, with the medial or big toe, being one. The first metatarsal is larger than the others due to its weight bearing function.
The foot has two arches that support the weight of the body and provide leverage when walking. The arches are formed by the bones held in place by ligaments and tendons. These arches are not rigid, but yield when weight is placed on the foot and spring back when weight is lifted.
All muscles originating on the lower leg except the popliteus muscle are attached to the bones of the foot. The tibia and fibula and the interosseous membrane separate these muscles into anterior and posterior groups, in their turn subdivided into subgroups and layers. Muscles of the lower leg originate at various points of the tibia and fibula but insert at various points of the foot. One familiar muscle, the tibialis anterior muscle, arises from the tibia and inserts on the plantar surface of the foot. The gastrocnumius (calf) muscle arise from posterior surfaces of the femur and insert onto the calcaneus bone via the common Achilles tendon. This muscle acts on two joints to flex the knee and the foot. There are a total of 13 muscles that originate on the lower leg and insert onto the foot. These muscles give the foot the ability to flex, extend, evert and invert.
The muscles acting on the foot can be classified into extrinsic muscles, those originating on the anterior or posterior aspect of the lower leg, and intrinsic muscles, originating on the dorsal or plantar aspects of the foot.
The intrinsic muscles are located within the foot and cause movement of the toes. These muscles are flexors (plantar flexors), extensors (dorsiflexors), abductors, and adductors of the toes. Several intrinsic muscles also help support the arches of the foot.
The extrinsic muscles are located outside the foot, in the lower leg. The powerful gastrocnemius muscle (calf) is among them. They have long tendons that cross the ankle, to attach on the bones of the foot and assist in movement. So, why the anatomy lesson you ask? I think it is important to know just how intricate the foot is. Also when you take into account that muscles in the lower leg have an impact on the foot and ankle. If you have a problem with the foot or ankle, it is going to move the kinetic chain or move up your body to create dysfunction and other joints. If the ankle and foot don’t move well, then you are going to have problems in the knee.
In the gym we work on ankle mobility by doing the “knee to wall” exercise in three directions. This exercise will help to improve the mobility through the boney portion of the ankle. Combine this with appropriate stretches for muscles in the foot and lower leg, you are helping to address problems that could have a much more far reaching effect.
Single leg work (single leg balance exercises) also help to strengthen muscles and tendons that support the foot. Helping to build strength in all the muscles of the foot will help to keep a much more stable platform. Remember the foot is the first point of contact and plays a huge role in how the rest of our body will function.
Till next time,