Sensory Nerves and Tendon Reflexes

Burning, numbness, tingling, and pain can be felt in the back, lower back,  legs, and feet. A lot of times these symptoms spread out/radiate from one part of the body into another area. Sciatica is an example of pain that radiates into an extremity, in this case, the back of the leg. Nerves originate from the spine and are divided/separated into sensory and motor nerves. The sensory nerve/s give the sensation to the skin known as dermatomes. Dermatomal patterns act as a map of the body.

Example: Dermatomes on the torso of the body react to the thoracic spinal nerve roots, the arms react to the cervical spine nerve roots, and the legs react to the lumbar spinal nerve roots.

Dermatome Location – Corresponding Spine Level

• Shoulders – C4, C5
• Inner/Outer Forearms – C6, and T1
• Thumbs and Little Fingers – C6, C7, C8
• Front of Thighs – L2
• Middle, Sides of Both Calves – L4, L5
• Little Toes – S1

A physician might use a piece of cotton, a swab, pin, or paperclip to test the symmetrical feelings in the arms and legs. Abnormal responses could be a sign of a nerve root problem.

Tendon Reflexes

Most individuals have experienced a physician tapping the knees with a rubber hammer. The normal response is a kick. This is a reflex, which is an involuntary muscular response generated by the hammer tapping the tendon. When the reflex responses do not present, this could mean that the spinal cord, nerve root, peripheral nerve, or muscle has been injured/damaged in some way. Absent reflexes are also clues to other conditions/injuries. An abnormal reflex response could also be caused by a disruption of the sensory (feeling) or motor (movement) nerves and sometimes both. Determining where the neural problem might be, a physician will test reflexes in various parts of the body.

Reflex Tested Areas – Corresponding Spine Level

• Upper Arm Biceps  – C5-C6 Cervical Spine
• Forearm Distal Radius – C6-C7
• Elbow Triceps – C7
• Abdominal – T8, T9, T10, T11, T12, Thoracic
• Knees/Thighs Patellar, Quadriceps –  L3, L4 Lumbar
• Ankles – S1 Sacral

Neurological Exams for Neck/Back Pain

Muscle Strength/Tone

Muscle strength and tone measurements are another way to diagnose nerve deficits. Depending on the symptoms/condition/injury/s there are different ways to evaluate muscle strength:

• Stepping on a stool
• Standing on the heels
• Standing on the toes
• Hopping in place
• Performing knee bends
• Gripping an item in each hand

Muscle strength is graded and recorded in the patient’s chart.

A physician will test the body’s muscle tone by passively flexing and extending the arms and legs. Normal muscle tone will respond with a slight resistance to passive motion. Other movements test for proximal (trunk/torso) and distal (distant) weakness. Muscle symmetry is also taken into account.

Neurological Tests

If necessary a spine specialist might order neurological studies like a Nerve Conduction Study (NCS) or Electromyogram (EMG), to measure nerve performance.

Imaging Studies

MRI and/or CT scans of the spine can be ordered to help the spine specialist/chiropractor make a correct diagnosis, as well as help in creating a plan of treatment.

Conclusion

A neurological exam, along with a mechanical examination consisting of movement of the arms, legs, and torso, can significantly help doctors in making the correct diagnosis. Examination results are then correlated with the patient’s history, illness, and diagnostic studies. Once the diagnosis is made an appropriate treatment plan is discussed. This will begin with non-surgical strategies but if those fail, then surgical intervention could be considered.

Peripheral Neuropathy Treatment