WHAT IS IT?
The pes anserine (meaning "goose's foot") is a conjunction of tendons from three muscles; the gracilis and sartorius are two groin muscles and the semitendinosus is a hamstring muscle. A fluid-filled sac (a bursa), located below the insertion point of the three tendons, can become inflamed due to excessive friction.
Swelling and pain are noticeable on the inside and front aspect of the knee, and may be painful upon palpation. Pain may be aggravated during exercise or going up or down stairs.
Health content provided by Dr. Reed Ferber and the Running Injury Clinic