Turf toe is a sprain of the joint at the base of the big toe. When the toe is repeatedly and forcibly bent upwards past what is considered a normal ROM in dorsiflexion, it can cause jamming of the joint around the big toe and may cause damage to the surrounding tendons and ligaments.
Your big toe has two joints. The metatarsophalangeal (MTP) joint is the largest of these. This is where the first long bone of your foot (metatarsal) connects with the first bone of your toe (phalanx). Important structures surround this joint and hold it in place. These include fibrous tissues under your MTP joint (plantar plate), ligaments located on the side of your big toe, a tendon that runs under your first metatarsal bone, and two small unattached tiny that help this tendon function.
Turf toe got its name because the injury became more common when football players began playing on artificial turf instead of grass. Artificial turf is harder and less shock-absorbent than grass. It is particularly common in professional athletes who play football or other sports on artificial turf, but it also occurs in a wide variety of sports and activities. It is relatively uncommon in people who are not athletes.