turf toe

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A sprain or tear of the ligament and other fibrous tissue surrounding the joint between the metatarsal bone and proximal phalanx of the big toe, often caused by hyperextension during athletic play on a rigid surface.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun an injury to the joint and connective tissue between the foot and one of the toes; frequently a sporting injury