As of March 4th Rotoworld is reporting four players listed as day to day with hamstring injuries and a fifth player, Marc Gasol out indefinitely with the same injury. I have no personal knowledge of the degrees or treatment plans for these injuries but in today’s blog I will discuss my experience with hamstring strains.
The hamstrings are the group of muscles behind the thigh. There are three muscles that make up this group. Two on the medial side (towards the midline of the body) and one on the lateral side (outside of the body). The medial hamstrings are the semimembranosus and semitendinosus which originate at the base of the pelvis, cross the knee joint and insert on the tibia.
Collectively the three muscles work together to flex the knee and extend the hip. The semitendinosus and semimembranosus also help to medially rotate the tibia (shin bone) on the femur (thigh bone) when the knee is flexed and medially rotate the femur when the hip is extended which counteracts forward bending at the hip.
The biceps femoris gets its name from Latin for having two (bi) heads (ceps). There is a long head that originates at the base of the pelvis and a short head that originates behind the femur. Distally they come together to form the conjoined tendon inserting on the head of the fibula. Both heads work together to flex the knee. Because the long head originates at the pelvis it is also involved in hip extension.
The reason why the origins, insertions and functions of the hamstring muscle group sound complicated is that they are. For instance, the long head of the biceps is a weaker knee flexor when the hip is extended and for the same reason, it is a weaker hip extender when the knee is flexed. This complex set of origins, insertions and functions become even more complicated because the hamstrings must work in synergy with the glutes, adductors (groin muscles), abductors (muscles that pull your leg away from the midline of the body), abdominal muscles, lower back muscles and deep pelvic floor muscles.
An easier explanation is the hamstrings are active in all movements of locomotion. They are an integral part of how the body transfers force through the pelvis especially during running and jumping. Newton’s third law on motion states: for every action, there is an equal and opposite reaction. Keeping with Newton’s law, how the hamstrings affect knee flexion, hip extension, tibial and femoral rotation will effect high peak ground reaction forces that contribute to the transmission of shock to the skeletal system.
Studies have shown that the hamstrings are eccentrically (lengthened) loaded during the late stance phase (when the foot is in contact with the ground) and late swing phase (when the foot is swinging forward not in contact with the ground) of running. There are also studies determining that the hamstrings are at a much greater length during the end of the swing phase just before heel strike which is thought to be when most hamstring injuries occur.
So if we know all of this what is the answer to the puzzle of hamstring injuries?
The solution to the puzzle of load transfer and the incidence of hamstring strain and hamstring re-injury is deeper than addressing prevention, treatment and rehabilitation of hamstring function. The true solution to the puzzle is in the loss of control of the lumbopelvic-hip complex also known as the core. If the pelvic girdle is not stable during load transfer than compensation will occur and injury risk will increase.
From my perspective, most of the treatment and rehabilitation of hamstring strains are directed at the site of pain which is the hamstring itself. There is enough evidence telling us the solution to hamstring pain and/or hamstring injury is lack of core control leading to poor movement efficiency and load transfer. Hamstring injuries are complex with a high rate of re-injury. This is an injury you cannot fix yourself or with a novice in the field. My best advice to you is if you are suffering from hamstring issues the solution is to find a good physical therapist or athletic trainer that is knowledgeable in evaluating and correcting pelvic girdle structure and function. They can put you through a series of functional tests to see if you are able to stabilize your pelvis during certain movements and direct you through a corrective program if you can’t.