Causes of a Pinched Nerve
Common causes of pinched nerves in the spine include herniated discs, bulging discs or degenerative disc disease. Other causes include compression of a nerve at the elbow or wrist, a prolonged cramped posture, arthritis, bone spurs, job injury or a tumor.
Symptoms of a Pinched Nerve
A nerve can be pinched as it leaves the neck or the back by a herniated disc or by bone spurs that form from spinal arthritis.
When one has a pinched nerve in the low back, pain is usually perceived as radiating down the leg. When one has a pinched nerve in the neck, pain emanates from the neck, through the shoulders, down the arms and into the hands.
Muscle spasms in the back commonly accompany pinched nerves and can cause weakness in the arm or leg. The two most common pinched nerves in the lower back are L5 (lumbar 5) and S1 (sacral 1).
Pinched nerves in the lumbar region:
Pinched nerve at L5 - The L5 nerve supplies the nerves to the muscles that raise the foot and big toe, and Read real testimonials from real patients consequently, impingement of this nerve may lead to weakness in these muscles. Numbness for L5 runs over the top of the foot. Pain will be in the lower back running to the hip, down the lateral part of your thigh and calf and to the top of the foot.
Pinched nerve at S1 - Impingement of the S1 nerve can lead to weakness with the large gastronemius muscle in the back of the calf, causing difficulty with foot push off. Numbness for the S1 nerve runs on the outside of the foot. Pain will be in the lower back running to the buttocks, down the back of the thigh and calf to the lateral aspect of the foot (to the little toe).
Pinched nerves at L3, L4 and L5 - The sciatic nerve is the largest nerve in the body. It starts in the low back at lumbar segment 3 (L3). The sciatic nerve roots run through the bony canal, and at each level in the lower back a pair of nerve roots exits from the spine. The nerve is named for the upper vertebral body that it runs between (for example, the nerve that exits at L4-L5 is named L4). The nerve passing to the next level runs over a weak spot in the disc space, which is the reason discs tend to herniate (extrude) right under the sciatic nerve root and can cause sciatica. The sciatica symptoms (low back pain, leg pain, numbness, tingling, weakness) are different depending on where the pressure on the nerve occurs. For example, a lumbar segment 5 (L5) nerve impingement can cause weakness in extension of the big toe and potentially in the ankle (foot drop).
Pinched nerves in the cervical region:
Pinched nerve at C5 - This can cause shoulder pain, deltoid weakness, and possibly a small area of numbness in the shoulder. On physical exam, a patient’s biceps reflex may be diminished.
Pinched nerve at C6 - This can cause weakness in the biceps and wrist extensors, and pain/numbness that runs down the arm to the thumb. On physical exam, the brachioradialis reflex (mid-forearm) may be diminished.
Pinched nerve at C7 - This can cause pain/numbness that runs down the arm to the middle finger. On physical exam, the triceps reflex may be diminished.
Pinched nerve at C8 - This can cause hand dysfunction (this nerve supplies innervation to the small muscles of the hand). Pain/numbness can run to the outside of the hand (little finger) and impair its reflex.