Reason for performing nerve examination when experiencing lower back pain and leg numbness

When pain descends from the lower back to the leg or when the leg feels numb, confirming only the intensity of the pain is insufficient.

The pain may be severe, but leg strength and sensation can be normal. Conversely, pain may decrease after analgesics or injection therapy, but weakness in the ankle may also occur.

Neurological examination is a test that assesses changes in the function of lumbar nerves or peripheral nerves in the legs through muscle strength, sensation, reflexes, and gait.

• When pain descends from the lower back to the buttocks and leg
• If your legs or feet feel numb
• If you feel numbness or if sensation differs between the left and right sides.
• If you feel weakness in your legs
• If you drag your foot or trip frequently
• If your legs hurt and feel numb after walking for a long time
• If new leg symptoms appear or worsen during treatment

This examination determines whether general musculoskeletal treatment can be initiated or if an MRI or visit to another medical institution is required first.

The medical team compares the strength of both legs by applying resistance with their hands or asking the patient to perform specific movements.

• The strength to lift the thigh
• Force to extend the knee
• Force that dorsiflexes the ankle
• Strength to lift the big toe
• Strength to push the foot downward at the ankle
• Walking on the heels
• Walking on the tips of the toes

If the strength of a specific movement is weak, it may be possible to examine whether there are changes in the function of the related lumbar nerve or peripheral nerve.

However, it is necessary to distinguish between severe pain that prevents exerting full strength and actual neurogenic muscle weakness.

Gently palpate various parts of the thigh, calf, and foot to compare left and right sensations.

• Front and outer side of the thigh
• Inner and outer sides of the calf
• Top of the foot and big toe
• The outer side of the foot and the sole of the foot

We examine whether the area of tingling felt by the patient matches the sensory changes identified in the examination.

Piercing the skin with a needle at home or testing sensation with hot objects poses risks of burns and wounds, so it should be avoided.

You can gently tap the tendons of the knee and ankle to check for a response.

If the reflex is diminished or there is a left-right difference, changes in the function of the relevant nerve can be observed. However, because reflexes are influenced by age, tension, and individual differences, a single result is not used to diagnose a disc.

Gait demonstrates how leg strength, sensation, and balance function in real-life activities.

• Does the foot drag on the ground?
• Is it difficult to walk on your heels?
• Is it difficult to stand on your toes?
• Whether the knee gives way
• Does the body tilt to one side?
• Is it unstable when changing direction?

If your gait has changed, you must inform the medical staff.

By lying down and lifting your leg or assuming a position that stretches the nerve, you can observe whether the usual leg pain is reproduced.

Simply feeling a pulling sensation in the back of the thigh and familiar pain extending from the buttocks down to the calf and foot should be interpreted differently.

This single examination alone does not confirm a disc herniation. You must check the pain pathway along with muscle strength, sensation, and reflexes.

If you experience the following symptoms, a prompt medical evaluation may take priority over Chuna manual therapy or general pain treatment.

• Sudden change in bowel and bladder control
• Numbness in the perineal area or inner buttocks
• Severe pain and numbness in both legs
• Leg strength decreases rapidly.
• Difficulty lifting the ankle and toes
• Dragging of the leg or sudden difficulty in walking

Such symptoms may require an MRI and specialist consultation to determine whether there is severe nerve compression.

This does not mean we can definitively conclude that.

Even with early nerve irritation or pain, muscle strength, sensation and reflexes may be normal. Conversely, the changes observed in the examination may also be related to peripheral nerves outside the lower back or other conditions.

Neurological examination results are interpreted in conjunction with the course of symptoms, physical examination findings, and imaging studies performed when necessary.

In the following cases, MRI may be considered.

• Progressive muscle weakness
• Changes in urination and defecation, and sensation in the perineal region
• If leg pain and numbness continue to worsen
• If severe functional impairment persists even after appropriate treatment
• When it is necessary to decide whether an injection or surgery is needed
• If infection, tumor, or other conditions are suspected

Not all patients with leg pain are immediately subjected to an MRI scan.

• Difference in leg muscle strength between left and right sides
• Area with diminished sensation
• Does the leg drag?
• Walking on the heels and toes
• How far pain and numbness or tingling travel down
• Walking distance and use of stairs
• Changes in urination and defecation, and sensation in the perineal region

Even if pain decreases, if muscle strength becomes weaker, it cannot be considered that the treatment is going well.

Chuna manual therapy may be considered when there is no progressing muscle weakness or urgent neurological symptom, and movement of the lower back and pelvis and musculoskeletal function need to be managed together.

Chuna manual therapy before and after, leg muscle strength and sensation, and pain range must be confirmed.

It is inappropriate to continue repeating the same treatment while neurological symptoms worsen, or to claim that Chuna manual therapy can definitely relieve compressed nerves.

Even if the pain has decreased, it is necessary to separately confirm whether leg strength and sensation are stable.

Especially, if the following changes occur, it is recommended to undergo re-evaluation.

• Pain has eased, but the foot drags
• The area of leg numbness has expanded.
• Difficulty climbing stairs
• Numbness may increase.
• Changes in urination and defecation functions

Symptom suppression and nerve function recovery may not be the same thing.