The hamstring muscles actively bend (flex) the knee. They also act to straighten or (extend) the hip (as in the motion of moving the thigh backward). Surprisingly, these large muscles are not very active with normal walking or standing. However, they are extremely important in power activities such as running, jumping, and climbing. Thus, sedentary individuals can get by with quite weak or deconditioned hamstrings, whereas athletes and very physically active individuals absolutely depend on healthy, well-conditioned hamstrings
You can't walk very well if you pull one.
I couldn't even walk for 3 days. Walking now--like an old man.
So back to the weights again.
Never pulled one before. It's never going to happen again. It hurt like HELL.
Hamstring injuries usually occur with sudden lunging, running, or jumping, resulting in muscle injury. The sudden jerking pulls on the tissues of the hamstring muscle. In fact, it is commonly referred to as a "pulled hamstring." Oftentimes, a "pop" is heard or felt by the injured athlete. A variable amount of pain is experienced immediately. The athlete is usually unable to continue and oftentimes cannot even stand.
Examination of the individual with a hamstring injury reveals spasm, tightness, and tenderness. With more severe injury, swelling and a black and blue or bruised appearance will follow. In some cases, a palpable defect (detectable by touching) will be present in the muscle. Tears and strains most often occur at the middle of the back of the thigh where the muscle joins its tendon or at the origin of the hamstring at the base of the buttocks (at the ischium).