Examination of the spine
The examination of the spine does not require special equipment but a thorough understanding of the anatomy and function of the spine, the spinal cord and nerves.
The history of preexisting spinal issues and traumas including their dynamics is documented prior to the physical examination to determine the possibility of underlying conditions. Depending on the severity of the pathology (e.g. fracture of the spine) free movement of the body may not be possible. Therefore the patient may be immobilised on a lying position to avoid the exacerbation of any structural damage causing injuries to the nerves and spinal cord.
If this is not the case, the patient is subjected to a range of movements (forward and backward bends, side to side) to assess existing mobility restrictions and presence of deformities of the spine, including changes in the vertebrae alignment, as in the case of scoliosis.
The presence of neurological symptoms is also critical. This follows a precise protocol based on testing the functionality of nerves and their corresponding terminal areas (dermatomes). The overall information obtained with medical examination may be followed by radiologic examination if required.
Important landmark for the spine
The alignment of the spine can be assessed when the patient bends forward and the spinal processes of the vertebrae become visible. Any deformation can be easily detected with the naked eye. During the examination of the spine anatomy specific vertebrae are more useful as landmarks to assess spinal instability. These are:
Cervical vertebra at the low part of the neck, C7
Last thoracic vertebra, T12
Sacral-iliac joint connecting the spine to the pelvis
Atrophy or reduction in the volume of the paravertebral muscles adjacent to the spine is an indication of functional abnormality due to neurological impairment. The appearance of hair around the anus (rima ani) is suspicious of spina bifida.
The initial inspection of the spine involves a thorough observation of the external appearance of the alignment of the vertebrae from the back of the head or occiput, to the lower section of the spine at the coccyx. This includes examination of asymmetry, deformity and atrophy of the adjacent muscles. It is important to identify the presence of scars, rashes and lesions, which can be a manifestation of underlying pathology.
The palpation of the spine involves a careful examination of each vertebra, by moving along the spinal processes on the spine length and applying a light pressure onto the lateral muscles. Palpation is a simple method to ascertain changes in tissue tension, texture and thickness and detect any feelings of tenderness. It also allows to appreciate abnormalities in the anatomical structures. With a direct touch to the spinal region, the examiner also becomes aware of changes in temperature and increased or reduced sensation.
Range of motion
Establishing the occurrence of any restriction in the flexibility and movement of the spine is key to determine the type and severity of a spinal pathology. The examination begins by allowing the patient to move through a set of active movements by bending forward, backward and twisting laterally on both sides. With the availability of a standardised range of normal motion it is straight forward for the examiner to calculate changes in spinal function.
Range of motion of the cervical spine
Start by asking the patient to move through an active range of motion
Neutral position - head up and chin in.
Forward bending (flexion) - 50 to 60°
Backward bending (extension) - 45 to 55°
Lateral bending, to right and left - 30 to 40°
Rotation right and left - 50 to 60°
Range of motion of the lumbar spine
Start by asking the patient to move through an active range of motion
Neutral position - spine in perpendicular position.
Forward bending (flexion) - 70 to 90°
Backward bending (extension) - 20 to 30°
Lateral bending, to right and left - 25 to 35°
Rotation, with the pelvis fixed, right and left - comparing angle made by shoulders with the pelvis - 30 to 40°
Tension sign/Bowstring test
Passive straight leg rise until pain is felt, flex the knee to release symptoms, apply pressure to the popliteal fossa (depression behind the knee joint). If pain returns it means sciatic nerve issues.
This test is used to determine if patient is malingering. The examiner cups the calcaneus of each leg with his/her hands. When the patient raises the leg straight, the examiner should feel pressure on calcaneus remaining onto the bed, which is used as leverage for the opposite, elevating leg. If no pressure is felt, the patient is simulating the spine problem.
Femoral nerve stretch test
Lying on the side, passively extend the leg at the hip with the knee bent at 90º. If pain, numbness or tingling is felt at the anterior/lateral thigh, it shows femoral nerve root impingement.
Stork/Single stance test
While balancing on leg, arch the spine backwards. If pain occurs, it indicates spondylolysis or spondylolisthesis.
A blunt object is run along the lateral side of the inner foot from the heel to the big toe (fanning of toes). The test is positive if the big toe extends and the other toes abduct. This is a plantar reflex and may indicate brain or spinal cord trau
The examiner runs fingernails gently along the crest of the patient’s calf bone (tibia). If the big toe extends and the other toes abduct, and plantar reflex it can indicate brain or spinal cord trauma.
The patient holds a deep breath and blows into the closed fist by strongly contracting the abdominal muscles. If spinal pain increases it may indicate a herniated disk.
The patient is asked to lift the feet of 2-6 inches off the bed for 30 seconds. If the patient is unable to lift, hold the legs or feels spinal pain, it may indicate herniated disk and impinged lumbar nerve.
Special tests are carried out to confirm nerve irritation of the spine.
Passive neck flexion
With the patient supine, the examiner places the hands on the posterior side of the head over the occiput. Next, the head is passively flexed anteriorly with the chin reaching the chest. A positive result is reproduction of neurological symptoms to the lower extremities.
Vertebral artery test
The patient is in a supine position and the head gently pulled and twisted to each side. If blurred vision, dizziness, slurred speech, level of consciousness (LOC) appear it may indicate a partial or complete obstruction of the vertebral artery.
Spurling test - Foraminal compression
With the patient in a sitting position, the examiner exercises pressure with both hands on the patient’s head pushing downwards and flexing and the head laterally.
If pain arises on the flexed side it may indicate pressure on cervical nerve roots caused by osteoarthritis, osteoporosis, spinal stenosis or instability of the cervical spine. If the vertebral artery test is also positive it suggests damage to the vessel.
Neck distraction test - Manual traction test
With the patient lying on a supine position, the examiner places one hand under the patient’s chin and the other on the occiput. The head is gently lifted and an axial traction force is gradually applied up to 30 pounds. The test is positive if the pain is relieved or decreased when the head is lifted or distracted, indicating pressure on nerve roots.
Shoulder abduction test
The patient places the hand of the affected extremity on the head to support the arm in the scapular plane. A positive response is alleviation of patient symptoms that are associated with the relief of a sensory sign (also named Bakody’s sign) possibly due to a disc protrusion, impinging on the nerve or the nerve root. When positive, this test is also combined with motor weakness, radicular paraesthesia, lateral extradural lesions and a good response to surgical treatment.
When the patient has difficulties in swallowing (dysphagia), this could be due to the obstruction of the cervical spine caused by subluxation, osteophyte protrusion, soft tissue swelling, tumors of the anterior spine or a pathology of the esophagus (i.e. herniation of the mucous membrane). Lateral views of the cervical spine demonstrated approximately 25% anterolisthesis in a bilateral facet subluxation. There is a narrowing of the central canal secondary to the anterolisthesis.
Tinel’s sign - Brachial plexus test
This test determines the status of the brachial plexus, which is a group of nerves exiting the vertebrae from C4 to T1 innervating the shoulder and the arm. The patient is sitting with the head slightly bent to the side. The examiner taps the brachial plexus of the same side along the nerves from the neck to the shoulder. A positive sign shows a tingling sensation on the nerve fibres, indicating a pathology of the brachial plexus.
Mechanisms of “burners.”
(A) Traction to the brachial plexus from ipsilateral shoulder depression and contralateral lateral neck flexion.
(B) Direct blow to the supraclavicular fossa at Erb's point
(C) Compression of the cervical roots or brachial plexus from ipsilateral lateral flexion and hyperextension.
Brachial plexus stretch test
Pathologies of the brachial plexus produce a feeling of electric shock, numbness or burning sensation at the neck radiating to the arm. (In most severe cases when the nerves are severed the movement of the shoulder, arm and fingers may be impaired). For the stretch test, the patient is seated and the examiner places one hand on the shoulder and the other onto the head and stretches the brachial plexus by flexing the patient’s head. By stretching the neck to the right the pain radiating to the left shoulder indicates a pathology of the plexus. Conversely, a pain sensation radiating on the opposite right shoulder, is indicative of possible impingement of the nerve roots.
The patient holds both arms at shoulder level and bent at the elbows. The hands are opened and closed to a fist. The test is positive if the patient is unable to maintain the position, shows reduced hand function, or loss of sensation in the upper extremities? This may indicate a thoracic outlet syndrome (disorders caused by compression to vessels or nerves between collarbone and first rib (thoracic outlet). This causes pain in shoulders and neck and finger numbness.
Straight leg raise
Straight leg raise (SLR) is used to determine the irritation of the lumbosacral nerve. While lying on the back, passively flex the straight leg from the hip up to 90 degrees. Pain should be felt at an angle between 30º and 70º and disappear when lowering the leg at 10º. If positive, this test demonstrates a possible herniated disk and irritation of the sciatic nerve.
Test for lumbosacral nerve root irritation. Patient is supine, and the physician passively elevates each of the patient's legs in turn, keeping the knee extended, and flexing at the hip to an angle of 90º.
This test is used for lumbosacral nerve root irritation and to discriminate between a nerve or muscle origin of lower back pain. The patient is supine, and the examiner lowers the patient's leg about an inch from the position in which pain was elicited. While holding the leg elevated, the patient's foot is passively dorsiflexed. If pain is increased, a nerve aetiology is likely at L4, L5, or S1 levels; conversely a muscle aetiology is likely if no pain arises.
Variations of straight leg raise test:
Once reached the leg elevation causing the pain, flex the knee. If no pain is felt with straight leg raise, flex the cervical spine to the chest and repeat the test. Pain should be relieved by flexing the knee (Kerning) or aggravated by flexing the neck (Brudinski). Used for herniated disk and dural sheath irritation.
Well straight leg raising test
The patient straightens and raises the opposite leg to the one causing pain. If pain is felt on the leg lying low, it may indicate a herniated disk.
Seated at table edge, bend forward, flex the neck, extend one knee and dorsiflex the foot. If sciatic pain occurs it indicates a problem to the sciatic nerve.
Neurology is a medical specialty dealing with disorders of the nervous system. It comprises the diagnosis and treatment of all categories of diseases involving the central, peripheral, and autonomic nervous systems, including their coverings, blood vessels, and all effector tissue, such as muscles.
The complex array of skin and muscle areas innervated by specific nerves, also named dermatomes, is examined to diagnose the existence of neurological deficits. Pain, numbness, and muscular atrophy/loss of strength of particular dermatomes are signs of pathology to a specific vertebral level. This can be the result of nerve impingement arising from a disc herniation, trauma or a neurodegenerative condition.
Nerves of the cervical spine
The cartoons summarise the sensory and motor function controlled by the nerves of the cervical spine and their corresponding dermatomes:
C7 Middle finger
C8 Little finger
Sensory nerves of the upper extremities
Sensory examination of the neurological triangle control of the lower arm.
Sensory function is controlled by nerves exiting the cervical vertebrae C6, and C8, and thoracic vertebra Th1.
Motor innervation of the upper extremities
Sensory nerves of the lower extremities and their roots of origin
Motor innervation of the lower extremities
Sensory examination of the thoracic nerves
The dermatomes on the thoracic and abdominal regions are controlled by nerves exiting the thoracic vertebrae Th4, Th7, Th10, and Th12, whereby each corresponds to the following landmarks:
Nerves of the lumbar spine
Sensory and motor function controlled by the nerves of the lumbar and sacral spine and their corresponding dermatomes:
L4 medial leg
L5 1st / 2nd toes
S1 lateral foot
The strength of muscles can be assessed using an empirical scale ranging from Grade 0 to 5:
5 Normal strength
4 Active power against both resistance and weight
3 Active power against gravity but not resistance
2 Active movement only with gravity elimination
1 Flicker or trace of contraction
0 No movement or contraction
Assessing paraplegia and tetraplegia
The level of paralysis is based on the ASIA Impairment Scale of The American Spinal Cord Injury Association. In order to help classify differing degrees of spinal cord injury, the ASIA impairment scale is used to compare and understand residual function.
A - Complete: No motor or sensory function in the lowest sacral segment (S4-S5)
B - Incomplete Sensory function below neurologic level and in S4-S5, no motor function below neurologic level
C - Incomplete Motor function is preserved below neurologic level and more than half of the key muscle groups have a muscle grade less than 3
D - Incomplete Motor function is preserved below neurologic level and at least half of the key muscle groups below neurologic level have a muscle grade 3
E - Normal Sensory and motor function.
Levels of paralysis
Methods to define the level of the paralysis:
Biceps jerk C5 /C6
Supinator jerk C6
Extensor digitorum reflex C7
Triceps jerk C7/ C8
Abdominal reflex T8-T12
Knee jerk L2 / L4
Ankle jerk L5 / S1 / S2
Bulbo-spongiosus reflex S2-S4
Anal reflex S5
Plantar reflex L5-S
After spinal cord injury the examiner will gather critical information on the nervous system by testing reflexes. The reflex arc is the pathway activated to trigger a reflex following a stimulus. It does not rely on brain function but is an independent neural circuit elicited by sensory nerves, e.g. in the skin, traveling to synapses in the spinal cord (green), to then stimulate motor nerves (purple) and rapidly trigger a muscular response.