I believe , it's a hyper-extention of a tendon or ligament in the foot .
Usually requires some time to heal .

Turf toe is an injury to the base of the big toe, in which you actually tear the capsule that surrounds the joint at the base of the toe. A turf toe injury usually occurs when the toe is jammed into the ground and bent too far back (hyperextended). This injury occurs most often in sports that require quick direction changes, such as football, soccer or rugby.

Turf toe is named after the artificial surface (turf) found on many playing fields. Increased grip provided by the artificial surface combined with the special shoes worn to play on such surfaces can increase the risk of this injury. However, turf toe can occur in any sport and on any surface.
Turf toe is a painful injury. The pain may be so severe that it causes limping and prevents running. A doctor may make a diagnosis by:

 Physical examination
 Medical history
 X-rays

Treatment usually includes:

 Applying ice to the toe
 Wearing a rigid-soled shoe or inserting a rigid plate into your shoe to prevent excessive toe movement

In more severe cases, treatment may include:

 Avoiding sports for up to six weeks
 Wearing a walking boot or cast to immobilize the toe
 Surgery, rarely

yep you hit the nail on the head

according to the mayo clinic this is the official definition...



Source file found here...
Turf toe - MayoClinic.com