Last month’s installment addressed pain in the back of the thigh from hamstring and lower-back injuries. Spinal nerve roots exit between the vertebrae in the spine. In some cases a disk’the shock absorber between the vertebrae’can become damaged and inflamed, which can cause back pain if the inflammation carries over to the spinal nerve. Once nerves are inflamed, they can display symptoms in the back and down its path, such as pain, numbness, tingling, a pins-and-needles sensation, electric-like feelings and weakness in the muscles supplied by the nerve. The size of the protrusion, or herniation, of the disk is not as significant a factor as was once believed.
The lower back is also called the lumbar spine. The five lumbar vertebrae are identified and numbered L1 through L5. The lumbar spine joins the pelvis at its center bony section, called the sacrum, which is composed of several naturally fused vertebrae. The sacrum section that’s most important for this discussion is the top section, S1. The nerves are numbered in a similar manner.
The two lowest nerves in the low back, L5 and S1, can cause pain radiating down the back of the leg. The distribution of that type of pain can vary. Some people have lower-back, gluteal, hamstring, calf and even foot pain. Others may have back and hamstring pain only. Some have pain only in the glutes or in the back of the thighs.
There are reasons why a trainee would have nerve-related pain in the hamstring region only. The first is that some types of disk injuries don’t cause back pain but instead thigh and leg pain. The second is that a trainee could have a narrowing of the space where the nerve exits the spine, a condition known as foraminal stenosis, which can be caused by bone spurs or disk protrusion in the space where the nerve exits or an overall bony buildup in the area.
A muscle under the gluteus maximus called the piriformis, originates, or attaches, on the outer edge of the sacrum and inserts on the top of the upper-thigh bone. The L5 and S1 nerve roots join there and form the sciatic nerve, which usually passes behind the piriformis. We’re not all anatomically identical (which surprises most patients), and in about a third of the population the sciatic nerve passes through that muscle. If it becomes too tight, the sciatic nerve can become irritated and produce pain in the back of the thigh.
Exercises that aggravate the hamstring muscles can irritate nerve-related pain. Stiff-legged deadlifts, Romanian deadlifts, cleans, good mornings and hypers, for example, all stretch the nerve. Usually any form of hamstring work that stretches the sciatic nerve or nerve roots makes the symptoms worse. That’s a key point. Most patients think they aren’t flexible enough, and they’ve heard that stretching is important for reducing back pain. So they perform hamstring stretches, especially with the foot pulled back. That just stretches the inflamed nerve even more, causing more symptoms; inflamed nerves don’t respond well to stretching.
What all this comes down to is that sometimes pain in the back of the thigh isn’t a hamstring strain but comes from the lower back. If you’ve experienced pain in the back of your thighs and it doesn’t seem to improve, see a neurosurgeon, an orthopedic surgeon with a spine specialty or a chiropractor with sportsmedicine or orthopedic specialty training. Don’t attempt to diagnose yourself. Increased pain from stretching or the aggravating exercises doesn’t give you a diagnosis or appropriate treatment plan.
Editor’s note: Visit www.softtissuecenter .com for reprints of Horrigan’s past Sportsmedicine columns that have appeared in IRON MAN. You can order the book, Strength, Conditioning and Injury Prevention for Hockey by Joseph Horrigan, D.C., and E.J. ‘Doc’ Kreis, D.A., from Home Gym Warehouse, (800) 447-0008 or at www .home-gym.com.