Hamstring Function

So let's start by taking a look at how the hamstring interacts with the muscles in the torso.  The hamstring pulls downward on the ischial tuberosity which causes posterior pelvic tilt.  The abdominal muscles pull upward on the anterior part of the pelvis which also causes posterior pelvic tilt.  In other words these muscles work synergistically to tilt the pelvis posteriorly.

This relationship works great because it spreads out the work that each muscle group is required to do and helps us avoid injury.  However, if this relationship is disrupted an injury can occur.  It is most common for us to see weak abdominals that disrupts this synergy.  When the abdominals can not pull up on the pelvis with sufficient force the hamstrings become over worked.  This results in chronic hamstring strain.  In this case hamstring strengthening will not rehabilitate the injury.  Hamstring strengthening will continue to reinforce the flawed pattern of hamstring dominance over the abdominals and this will simply lead to further hamstring injuries.  In this situation the best course for correcting the hamstring injury is abdominal strengthening.

The hamstring also has a synergistic relationship with the gluteus maximus muscle.  Both muscles have attachments above and below the hip joint.  Therefore both muscles can extend the hip.  Again this relationship works because it spreads out the work of hip extension.  However, if this synergy is disrupted an injury can occur because one of these muscles will become over worked.  Most often what we see is weak glutes.  Glute weakness causes the hamstring to perform most of the work in extending the hip.  This excessive work leads to hamstring strain and again hamstring strengthening will simply reinforce the faulty pattern of the hamstring being the dominant hip extensor.  Therefore, in this situation the best rehab program would be to strengthen the glute.

In conclusion, if you find yourself in the situation of having athletes with chronically sore hamstrings it is most likey that you do not need more hamstring strengthening.  What is most likey the case is that the hamstring's synergists need to be strengthened in order to reduce the hamstring's work load.  So for healthy hamstrings what we really need are glutes and abs!