Lumbar disc herniation
Concept of disease
Lumbar disc herniation is the most severe cause of lower back pain. It may cause serious problems such as nerve palsies if left untreated. It occurs mainly in young people (in their 20s and 30s), but it also occurs in younger people (in their 10s) and middle-aged people (in their 40s). Be careful when numbness in the legs and sciatica have appeared severe lower back pain. Because this condition could lead to career-ending injury and differential diagnosis from other lower back pains when appearing first, the athletes should always seek medical attention.
Cause and mechanism of onset
With the application of stress to the intervertebral disk by the sport, the intervertebral disk raptures and the nucleus pulposus protrudes posteriorly from the middle.
In most cases, the annulus fibrosus of the fourth or fifth lumbar spine disc degenerates, and the nucleus pulposus may protrude behind the lumbar spine, and compresses the fourth lumbar nerve (L4), the 5th lumbar nerve (L5), and the 1st sacral nerve (root) (S1). Consequently, a variety of symptoms may develop, depending on the location of compression. The symptoms of the lower extremity are often unilateral because only either one nerve of left and right nerve of roots is often compressed. A herniation is a displacement of the nucleus pulposus from the normal position (intervertebral disc) or a lumbar disc herniation in the lower back.
Low back pain, pain during exercise (forward flexion of the trunk), numbness of the lower extremity (mainly on one side), sensory disturbances in the affected leg, and motor nerve palsies. In severe cases, dysuria and muscle atrophy of the thigh and leg may also appear with a prolonged duration.
Characteristics of pain
It is characterized by lower back and buttock pain in growth period and lower extremity pain in adults. Particularly, pain during exercise is more likely to occur during trunk anteflexion. It is more severe in lumbar spinal muscles, and the physiologic lordosis of the lumbar spine disappears and anteroposterior flexion of the trunk is limited. Differential diagnosis of lumbar spoindylolysis is characterized primarily by pain on backward bending of the trunk.
The SLR test* (sciatic nerve extension) sees leg elevation to 90 degrees (Photo 1). In addition, check the area of perceptual disturbance (region, bilateral difference and level), and manual muscle testing (MMT) to check bilateral difference in strength of anterior tibial muscle (L4), extensor hallucis longus (L5), and gastrocnemius (S1) muscles, and see if there is sciatica in the buttocks.
* SLR test means Straight Leg Raising test. It is a test that the person lies supine and raises the feet upward to see if the pain is induced.
Photo 1: SLR test at a 90 degrees. It is the easiest check for sciatica, but it is necessary to distinguish athletes who simply has stiff hamstrings
Currently, MRI (Photo 2) is the least invasive method and provides an easy way to determine the location and extent of herniation. Other procedures include plain X-ray, myelography, radiculography, contrast-enhanced CT and electromyography.
Photo 2: MRI shows lumbar spine degeneration of the fourth and fifth disc with darkening and prominent mild posterior herniation
Treatment and rehabilitation
Conservative treatment is the first choice. During the acute phase, rest is maintained and anti-inflammatory analgesics are administered. When the angle of the SLR is restored to 90 degrees, the patient stretches in the anteflexion position of the trunk with trunk rotation stretching with holding the knees. In addition, pelvic traction and electrotherapy could be done, and furthermore, nerve root blocks or epidural blocks could be done to inject anesthetic into the nerve if these treatments do not relieve symptoms. Surgery is indicated in severe cases that the symptoms are not relieved after at least 3 weeks of the above conservative treatment would have done. Surgery may include a Love procedure, in which the lumbar spine’s laminae are opened from the back to make hernia removed directly, and percutaneous nucleus pulposus extraction would apply these days. In younger patient with mild cases, laser burning of the nucleus pulposus may be performed.
Rehabilitation begins with trunk stretching with holding the knees after the SLR angle has returned to 90 degrees, and lower back pain has decreased. However, pain in the lower extremity may not improve with rest. Especially because the hamstrings are stiff, perform the SLR stretching of the lower extremity with the knee flexed while avoiding developing sciatica in early rehabilitation. Restarting abdominal and back exercises should not be maximized initially, and make sure to do gradually while decreasing the frequency and avoiding painful posture. Long-term running should be done with caution because the trunk swaying may irritate nerves and worsen symptoms. At the beginning of rehabilitation, it is desirable to use a support for lower back pain (Photo 3), and take rehabilitation period for three months as one cycle. Not surprisingly, it is important that t prompt restoration measures are more likely leads to recurrence.
Photo 3: Support for lower back pain: Combined application of the support (corset) to protect the lumbar spine reassures when starting rehabilitation or returning to competition.
A 26-year-old man was selected for a member of the national volleyball team in Japan after 4 months of league matches. However, strong lower back pain, right inferior limb pain, SLR of 45 degrees, minus 40 cm in standing position bending forward and a limitation in range of motion of the trunk were observed obviously at the medical check. There was decreased sensation of the lateral side of the right leg, with weakness of the extensor hallucis longus (Manual Muscle Testing 4, called MMT4). MRI showed a change (blackening) due to degeneration of the lumbar spine of the fourth and fifth intervertebral disc and slight herniation protrusion. Rest with conservative treatment (with above rehabilitation) was immediately started, and the patient was able to return to the competition about 4 months later.