The great toe joint is called the 1st metatarsal phalangeal joint, or 1st MPJ. The joint consists of the 1st metatarsal and the proximal phalanx. The hallux is the big toe and is composed of the distal phalanx and proximal phalanx. The lateral collateral and sesamoid ligaments help to stabilize the joint. The sesamoid are small bones under the great toe which function like ball bearings. Some individuals develop sesamoiditis, pain and inflammation around these small bones. More information on sesamoiditis.
A bunion is the most common condition occurring at the great toe joint. A bunion is a structural change in the foot.
In the picture to the right, the great toe is moving toward the smaller toes, while the 1st metatarsal is moving toward the center line of the body. This is the structural change that creates the deformity, commonly described as a "bump" on the great toe.
More information, images and diagrams on bunions.
The great toe joint is a common place to develop arthritis. A tremendous amount of weight is placed through the great toe when walking. Abnormal foot mechanics can contribute to additional stress through the great toe joint.
More information and diagrams on arthritis of the foot and great toe joint.