Physical examination serves to further explore and confirm the findings from the clinical history. Objective data obtained from the examination are essential to accurately diagnose the etiology of the pain. This chapter provides an overview of a structured approach to the physical examination of a pain patient, along with the anatomic and physiologic basis of the physical findings.
The key components of the physical examination include a general physical examination, a detailed neurologic examination, a detailed musculoskeletal examination, and an examination for cutaneous or trophic findings. The musculoskeletal examination includes inspection, palpation, percussion, auscultation, and provocative maneuvers.
General Physical Examination
Vital signs, including temperature, heart rate, respiratory rate, blood pressure, and weight, should be noted at each visit. This information is useful in forming an impression of the overall health and comorbid conditions of the patient.
A few moments should be spent in observing and documenting the general appearance and gait of the patient. Whenever possible, the examining physician should make every effort to bring the patient back to the examining room from the waiting room. This allows the physician the opportunity for examination as the patient transitions from sitting to standing and ambulates to the examining room. This observation time allows an “unofficial” examination that may reveal inconsistencies not noted on the “official formal” examination.
Attributes include how the patient dresses and personal hygiene. Pain behavior, posture, and anatomic abnormalities such as contractures, amputation, and asymmetries should also be noted. Maladaptive postural dynamics play an important role in generating myofascial pain. Excessive lumbar lordosis places strain on the lumbar extensor muscles and results in low back pain. Similarly, forward flexion of the cervical spine with drooping of the shoulders strains the cervical paraspinous and scapular muscles and thereby causes neck and upper back pain.
Evaluation of gait includes assessment of stride length, base, arm swing, and stability. An unsteady, wide-based ataxic gait can be seen in patients with cerebellar and proprioceptive disorders. In patients with hip and lower extremity pain, the stance phase is reduced in the affected limb, along with a shortened swing phase on the uninvolved side, which results in an antalgic gait pattern. A waddling gait can be seen in patients with weakness of the hip girdle muscles or bilateral degenerative hip joint disease. A multitude of gait deviations can occur in patients with footdrop, including vaulting, steppage gate, circumduction, and persistent abduction of the affected limb.
Mental Status Examination
A reasonable assessment of mental status can often be made as part of history taking and inquiry into activities of daily living and function. A basic mental status examination includes assessment of the level of consciousness; orientation to person, place, time, and situation; registration and short-term memory; attention and concentration; and assessment of language for aphasia. The Folstein Mini-Mental Status Examination is a useful screening tool for detecting cognitive deficits and dementia.
Assessment of mood, affect, suicidal and homicidal ideation, and neurovegetative symptoms such as sleep, appetite, and energy level should be inquired about routinely. This helps uncover comorbid psychiatric conditions (e.g., depression, anxiety, and psychosis), which can have a profound impact on the treatment of pain patients.
Cranial Nerve Testing
The cranial nerve examination localizes pathology primarily at the level of the brainstem. Central pain conditions associated with brainstem pathology (e.g., strokes, tumors, demyelinating disease, and vascular malformations) can be associated with cranial nerve deficits.
Cranial Nerve I
Olfactory Nerve
Test one nostril at a time. Odors such as coffee, mint, or cloves can be used. Noxious odors such as ammonia should be avoided because they activate trigeminal nerve receptors in the nasal passages.
The most common cause of smell dysfunction is nasal and sinus pathology. Dementia, neurodegenerative conditions, and basal frontal tumors can also result in smell dysfunction.
Cranial Nerve II
Optic Nerve
Visual acuity is determined with a Snellen chart. Visual fields are tested by the confrontation method at the bedside. More formal visual field testing with perimetry can be requested if indicated. Pupillary reaction to light and accommodation tests the optic and ophthalmic nerves. Funduscopic examination is done to evaluate the optic disc and retina. Papilledema and enlargement of the blind spot can be seen in conditions associated with elevated intracranial pressure, including idiopathic intracranial hypertension, which is a relatively common cause of intractable headache.
Cranial Nerves III, IV, and VI
Ophthalmic, Trochlear, and Abducens Nerves
These nerves control eye movement and can be tested by asking the patient to track a moving object in the eight positions of cardinal gaze. Eyelid elevation and pupillary constriction are controlled by the third cranial nerve and are evaluated by assessing the direct, consensual, and accommodation reflexes. Sympathetic fibers innervate the pupillary dilator muscles. Horner’s syndrome can be detected in several clinical conditions, including after stellate ganglion blockade. This syndrome includes ipsilateral ptosis, miosis, and anhidrosis. However, the mechanism of these changes involves sympatholysis and is independent of cranial nerve function.
Cranial Nerve V
Trigeminal Nerve
This nerve supplies sensory input to the face, mouth, tongue, and scalp up to the vertex. The mandibular division of the trigeminal nerve also supplies the muscles of mastication (i.e., temporalis, masseter, medial, and lateral pterygoid muscles).
Sensation along the ophthalmic, maxillary, and mandibular divisions of the trigeminal nerve can be tested with temperature, pinprick, and light touch. The trigeminal nerve also provides the afferent limb of the corneal blink reflex.
Peripheral lesions of the trigeminal nerve result in ipsilateral loss of facial sensation with weakness and atrophy of the ipsilateral jaw muscles.
Cranial Nerve VII
Facial Nerve
The facial nerve innervates the muscles of facial expression, the submandibular and lacrimal glands, and taste in the anterior two thirds of the tongue. Testing is usually limited to checking facial motor function (e.g., forehead wrinkling, eye closure, smile, pursing lips, and corneal blink). Supranuclear lesions of the seventh nerve typically spare the forehead, whereas nuclear and infranuclear lesions do not.
Sensory testing of the facial nerve is not routinely performed but can be accomplished by applying sweet, sour, and salt stimuli to the ipsilateral half of the anterior two thirds of the tongue.
Cranial Nerve VIII
Vestibulocochlear Nerve
The vestibulocochlear nerve mediates hearing and balance. Hearing can be assessed with a 512-Hz tuning fork. The Rinne and Weber tests are commonly used to assess for sensorineural and conductive deafness.
In the Weber test, the base of a gently vibrating tuning fork is placed on the midforehead or the vertex. The patient is asked which ear hears the sound better. Normally, the sound is heard equally in both ears. With unilateral sensorineural hearing loss, sound is heard better in the unaffected ear. With unilateral conductive hearing loss, sound is heard better in the affected ear.
The Rinne test is conducted by placing the base of a gently vibrating tuning fork on the mastoid bone behind the ear. When the patient can no longer hear the sound, the fork is quickly moved next to the patient’s ear. In patients with sensorineural deafness and normal hearing, air conduction is better than bone conduction. With conductive deafness, bone conduction is better than air conduction.
Nystagmus noted on eye movement testing may be a sign of vestibular dysfunction. In patients with complaints of episodic vertigo, the Dix-Hallpike maneuver is useful for making the diagnosis of benign paroxysmal positional vertigo.
Cranial Nerve IX
Glossopharyngeal Nerve
The glossopharyngeal nerve subserves taste in the posterior third of the tongue and sensation in the pharynx. It provides the afferent limb of the gag reflex.
Cranial Nerve X
Vagus Nerve
The vagus nerve innervates the pharyngeal and laryngeal muscles and forms the efferent limb of the gag reflex. Symptoms of vagus nerve lesions include dysarthria and dysphagia.
Cranial Nerve XI
Accessory Nerve
The cranial segment of the accessory nerve supplies the muscles of the larynx, whereas the spinal segment innervates the trapezius and sternocleidomastoid muscles. These muscles are tested by ipsilateral shoulder shrug and contralateral head turn maneuvers.
Cranial Nerve XII
Hypoglossal Nerve
The hypoglossal nerve provides motor supply to the tongue. Testing is performed by tongue protrusion and pushing the tongue against the cheek on either side. Lesions of the hypoglossal nerve produce ipsilateral deviation on tongue protrusion.
Motor Strength Examination
Manual muscle testing is performed by asking the patient to place each muscle in its position of maximal mechanical advantage. Muscle strength is commonly assessed with the Medical Research Council scale ( Table 13.1 ). Grades 1 to 3 are relatively objective and less prone to interobserver variation. Grade 1 implies a palpable contraction but with no associated movement noted. Grade 2 implies an ability to move the limb with gravity eliminated (this may require special postioning to assess). A grade 3 finding on motor examination is consistent with the ability to move against gravity but an inability to move against further resistance. The gastrocnemius muscle presents unique challenges when performing a manual muscle test. In the case of the gastrocnemius, a grade 3 muscle is able to perform one toe raise with the patient standing and lightly holding onto something for balance. A grade 4 muscle is able to perform 5 toe raises, and a grade 5 gastrocnemius is capable of performing 10 toe raises. Grades 4 and 5 are difficult to standardize among different examiners. Factors such as a patient’s body habitus, age, and expected functional status, as well as examiner strength, contribute to the difficulty of grading muscle strength above grade 3.
| Grade 0 | No movement |
| Grade 1 | Flicker of movement |
| Grade 2 | Movement only with gravity eliminated |
| Grade 3 | Full range of movement against gravity |
| Grade 4 | Full range of movement against some resistance |
| Grade 5 | Full power against resistance |
The screening muscle strength examination should correspond to a template that evaluates sequential nerve roots and peripheral nerves. Tables 13.2 and 13.3 provide a summary of the commonly tested muscles along with their corresponding nerve root and peripheral nerve innervation.
| Muscle | Action | Nerve Root | Nerve |
|---|---|---|---|
| Infraspinatus | Shoulder external rotation | C5-6 | Suprascapular |
| Deltoid | Shoulder abduction, extension, and flexion | C5-6 | Axillary |
| Biceps | Forearm flexion and supination | C5-6 | Musculocutaneous |
| Triceps | Forearm extension | C7-8 | Radial |
| Brachioradialis | Forearm flexion in the midprone position | C6 | Radial |
| Extensor carpi radialis longus and brevis | Wrist extension | C6-7 | Radial |
| Flexor carpi ulnaris | Wrist flexion with ulnar deviation | C8-T1 | Ulnar |
| Flexor digitorum profundus | Flexion at the distal interphalangeal joints | C7-8 | Anterior interosseus branch of the median nerve |
| Abductor pollicis brevis | Abduction of the thumb | C8 | Median |
| Adductor pollicis longus | Abduction of the thumb | C8-T1 | Ulnar |
| Muscle | Action | Nerve Root | Nerve |
|---|---|---|---|
| Iliopsoas | Hip flexion | L2-4 | Femoral |
| Adductor longus and brevis | Hip adduction | L2-4 | Obturator |
| Gluteus maximus | Hip extension | L5-S2 | Inferior gluteal |
| Gluteus medius and minimus | Hip abduction | L5-S2 | Superior gluteal |
| Quadriceps femoris | Knee extension | L2-4 | Femoral |
| Hamstrings (i.e., semitendinosus, semimembranosus, and biceps femoris) | Knee flexion | L5-S1 | Sciatic |
| Tibialis anterior | Foot dorsiflexion | L4-5 | Deep peroneal |
| Extensor hallucis longus | Extension of the big toe | L5 | Deep peroneal |
| Peroneus longus | Foot eversion | L5 | Superficial peroneal |
| Gastrocnemius/soleus | Foot plantar flexion | S1-2 | Tibial |
| Tibialis posterior | Foot inversion and plantar flexion | L5-S1 | Tibial |
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