Hamstring Tightness Versus Sciatic Nerve Tension: Which Is It?
- Posted on: Nov 26 2019
Tightness down the back of one’s leg – anywhere from the buttock, through the thigh, and into the lower leg – is a very common symptom in many people. It seems as if the general population views this sensation as hamstring tightness and, thus, attempt stretches that are either known or researched to combat the sensation. However, the concept of sciatic nerve tension is rarely considered when one feels tightness in the posterior leg. This is not to say that the two are mutually exclusive, but rather that the sciatic nerve can play a role in leg tightness and, therefore, should be addressed as well.
The hamstrings are comprised of three muscles: biceps femoris, semitendinosus, and semimembranosus. All three are primarily flexors of the knee, meaning they fire to make the knee bend, but they are also involved in movement at the hip. Because many activities that we do nowadays involve sitting, such as computer use, television watching, eating, driving, etc., the knee is often kept in a flexed position, thus allowing for the hamstring muscles to tighten. Once tight, these muscles are not able to fire optimally for activities such as standing from a seated position, walking, stair climbing, running, and other weight bearing activity. Stretching of the hamstring muscles can be done in several positions, but each stretch generally involved keeping the knee extended (that is, straightened) and flexing forward at the hip. Example:
The sciatic nerve originates from several nerve roots in the lumbar spine (that is, lower back), which then combine into a cord-like structure that travels down the back of the leg from the buttock, through the thigh, and behind the knee before branching into several smaller nerves in the lower leg and foot. Like the hamstring muscles, the sciatic nerve and its branches can become tense. Causes of sciatic nerve tension include, but are not limited to, prolonged positioning, trauma, and compression or impingement. Once tense, the sciatic nerve can also limit leg range of motion, just as the hamstring muscles might do. Unless hamstring tightness, which is usually felt as a general muscle tightness, symptoms of sciatic nerve tension include sharp pain, electric-like pain, burning, and numbness/tingling. In general, nerve tissue does not respond well to prolonged, static stretching like muscles do. So how does one relieve sciatic nerve tension?
Nerve tissue is usually encased in a sheath (picture sausage casing and its filling). While nerves do not respond well to a static stretch, nerves can be glided with specific movements. Considering the sciatic nerve specifically, a simple nerve glide can be performed independently. The movement is very much like what is done to pump back and forth while on playground swings. While seated on the edge of a high, sturdy surface, one would lean backward with legs extended and toes flexed toward the face. Then one would lean forward, bending the knees, and pointing the toes downward. Alternating between these two positions repetitively for several seconds to a few minutes at a time allows the sciatic nerve to be glided slightly downward toward the feet (position 1) and then upward toward the hips and back (position 2). Example:
Once sciatic nerve gliding is performed, most people experience an immediate relief or reduction in leg tightness and even an improved ability to perform a hamstring stretch. So, if you ever notice tightness in your legs, try this out and see if it helps. You might just have some nerve tension that needs addressing. And, as always, if you need more in depth instruction or treatment, your physical therapists here at AOSMI are always happy to help!
Rob Kohutanycz, PT, DPT
Posted in: Physical Therapy