The hamstring group of muscles is part of the posterior chain of the hip/ leg. They are not as large as the quadriceps on the anterior side of the body; they have more length to them and are more tubular than broad. However they are equally important, as they are responsible for hip extension and knee flexion. Hence they are used a lot for every day walking and running. The hamstrings are antagonists to the quadriceps muscles. The muscles that work in synergy with the hamstrings are gluteus maximus, sartorius, gracilis and the gastrocnemius.
All three hamstrings originate at the ischial tuberosity; they broaden out and then become slimmer as they get closer to the knee, ultimately ending in long thin tendons posterior to the knee. All three insert at different points. The biceps femoris long head inserts at the head of the fibula, and the biceps femoris short head at the lateral lip of the linea aspera. The semitendinosus inserts on the proximal medial shaft of the tibia. The semimembranosus inserts on the posterior aspect of medial condyle of the tibia. The latter two insertions along with the sartorius and gracilis form a duck foot like insertion called the pes anserinus.
Because the hamstrings are biarticular, they will affect the health of the knee, hip and even back. Most athletes who are tight in their hamstrings can suffer a host of problems. For example, when squatting with a heavy weight, they will not be able to lower their hips past 90 degrees. This keeps them working in a ‘safe’ mid range zone, but exasperates the issue as the hamstring will not be fully lengthened. Then when it comes time to explode out of the squat, the full length of the hamstring muscles are not utilized. This can get into a vicious circle, ending in weak and tight hamstrings.
Tight hamstrings also shed light on knee pain. Again, let’s take the bottom of a heavy squat example. If the hamstrings are too tight and do not allow full hip extension, the quadriceps will take over from the inefficient hamstrings, putting a tremendous load and strain on the knee. Remember, all four quadriceps converge to form a single tendon above the knee that attaches to the top and sides of the patella, before attaching via the patellar ligament to the tibial tuberosity. So if the quadriceps group works needlessly overtime, it’s going to affect the knee.
And there’s more! Back pain also can be attributed to tight hamstrings. Since the hamstrings are attached to the ischial tuberosity, tightness can tilt the pelvis back. When this happens the lumbar vertebrae flex forward, adding compression to the vertebral discs. It gets worse if we bend forward as the flexion is then coming from the lumbar spine.
Strengthening your hamstrings or keeping them strong is just as important. Most dominance in sports comes from hip extension/explosion. Take a runner as an example. If a runner continually loads his anterior chain while running, he will weaken his hamstrings. This pertains to proper running technique, whereby the hamstrings are asked to fire every time the leg is picked up off the ground. The inability to fire the hamstrings, can cause the hamstrings to tear, as they will not be able to take the constant load developed by the contracting quadriceps and the momentum that the hip extension generates. There will be a drop in running speed as the hip flexors jam up, and the hamstrings contract earlier in the stride.
If you’re looking for a great hamstring stretch (among other things), check back for a clip on Friday!