Pulled Hamstring Treatment

Hamstring Anatomy

A pulled hamstring is the same injury as a hamstrings strain. It is also one of the most common injuries suffered in athletics including baseball. 8% of all Major League Baseball injuries were hamstrings strains from 2002-2008 according to Posner, et al. Before we dive too deeply into this topic it is important to understand the hamstrings muscles and what constitutes a strain.

This image, courtesy of learnmuscles.com, shows the three muscles of the hamstrings: the semimembranosus, semitendinosus, and biceps femoris. All three muscles originate from ischial tuberosity which is the bump you feel in the lower part of your glutes, sometimes referred to as your “sit bone”. There is a short head of the biceps femoris that comes from the femur itself. All 3 muscles attach at the knee, with the semimembranosus and semitendinosus attaching to the tibia and the biceps femoris inserting into the fibula. The tibia is the inner bone of your lower leg and the fibula is the outer bone. All 3 muscles bend your knee as well as extend your hip backwards. Interestingly, 79-84% of hamstrings strains involve the biceps femoris, and it is thought to play a more significant role in the action of the hamstrings.

There are many theories for why the hamstrings are so often strained. One of the reasons is that it is constantly stressed eccentrically, meaning when it lengthens. Muscles that are engaged while lengthening create greater tissue damage, which could lead to more strains. Also, there are a high amount of Type II muscle fibers in the hamstrings relative to other leg muscles. Type II muscle fibers are your “fast twitch” fibers. They receive less oxygen but have greater power potential. You recruit these muscles with springing or heavy lifting so they require greater power but