Anatomy of the Hamstring Muscles Home -> Advanced Training -> Muscular Anatomy -> Hamstring Anatomy Anatomy Chart courtesy of FCIT The Hamstrings are actually comprised of three separate muscles: the Biceps Femoris, Semitendinosus and Semimembranosus. These muscles originate just underneath the Gluteus Maximus on the pelvic bone and attach on the tibia. The Hamstrings are primarily fast-twitch muscles, responding to low reps and powerful movements. Functions The "commonly thought of" primary functions of the Hamstrings are knee flexion (bringing the heel towards the buttocks) and hip extension (moving the leg to the rear). An example of knee flexion is the leg curl exercise and an example of hip extension is the stiff-legged deadlift exercise. In movement, the hamstrings "primary" function is NOT knee flexion. In walking or running, for example, the primary function of the hamstring is to decelerate the lower leg in the saggital plane. Positionally, knee flexion in walking/running occurs as a result of hip flexion and plantarflexion, again positionally. When the body responds to gravity, function changes (thank you to Jonathan Hewitt, APT - Athletic Enhancement Systems, for this contribution!) Exercises Exercises that work the Hamstrings include: Leg curls Lunges Stiff-legged deadlifts Standing leg curls Squats Body leg curls Here is a list of unique exercises and articles for the hamstrings that have been published in our monthly training newsletter "BetterU News" and on our membership site Powerful Training Secrets Free Trial area (these links will open in new windows). The Most Amazing (and Ridiculously Simple) Trick For Stiff-Legged Deadlifts You Will Ever Read In Your Life! Secret Training Tip #242 - Be 10% Stronger in Leg Curls Instantly! Secret Training Tip #961 - Hanging Dumbell Leg Curls