Hamstring Stretching... REVISITED
Furnished by Robert C. Tillman PT, MOMT

       It is a general observation that during warm-up periods for the novice and elite athlete, the hamstrings are often the most commonly stretched muscle groups regardless of the type of sport. It is also a general observation that the hamstrings, as a group, are the most often pulled or strained muscle group presenting for rehabilitative intervention.

       Some of you may remember an unfortunate situation that occurred with a college football team this past season. A week before an important bowl game, one team announced that four of their top five receivers had hamstring strains..... Four out of five.

To our knowledge, there is no such thing as a "Hamstring Virus" so we must continue our diligence in analyzing clinical practice and outcomes. With this in mind, let's take a look at the practice of "Hamstring Stretching".

       We will point out two possible reasons for complications with this muscle group secondary to the application of commonly accepted stretching techniques, one histological and the other neurophysiological.

       Individuals are often instructed to perform passive hip flexion with knee extension in either the sitting or standing positions with some degree of applied passive overpressure until they perceive a pulling sensation or even slight discomfort. The old concept of "no pain, no gain" in full effect. One common site for complaints of discomfort is at the point of origin for the long head of the biceps femoris (medial hamstring). It arises from an inferiomedial impression on the upper area of the ischial tuberosity via a tendon which it shares with the semi-tendinosus, and from the lower part of the sacrotuberous ligament which is the primary stabilizing ligament of the pelvis checking posterior rotation of the innominate bone on the sacrum. Over zealous passive elongation of the posterior thigh tissues leads to a strain of the connective tissues that attach in this area. Some proximal hamstring problems can be attributed to aggressive passive stretching techniques.

       From a neurophysiological perspective, if we apply enough of a deformation force to connective tissue, we then activate type four or nocioceptive mechanoreceptors and create a state referred to as a segmental facilitation. That (in simplified terms) means that the nervous system becomes more sensitive and responds with some type of sympathetic reaction, pain response and a reflexive increase in muscle tone. Aggressive, passive stretching of the hamstrings may in fact increase their resting tone, decreasing their extensibility during function activities and increase chances of strains.

***** A suggested way to avoid either of the above stated pitfalls is to activate the quadriceps while trying to access range of motion in hip flexion with knee extension in a pain free range of motion. This will reflexively decrease hamstring tone and assist in training the central nervous system to allow this range of motion during functional activities.