Table 2: Classification of Proximal Hamstring Injuries.

Level of Injury
Type 1 Osseous avulsions (generally seen in pediatric patients)
Type 2 Avulsions at the muscular-tendinous junction
Type 3 Incomplete tendon avulsions
Type 4 Complete avulsions with no/minimal retraction
Type 5a Complete avulsions with retraction but NO sciatic nerve involvement
Type 5b Complete avulsions with retraction AND sciatic nerve involvement