목 시험

The significant motion that occurs in the neck places the cervical spine at an increased risk of injury and degenerative changes. Therefore, the neck exam focuses on assessing this underlying structure.

The cervical spine is composed of seven vertebrae stacked in a gentle, lordotic C-shaped curve. The elements of these vertebrae include: the laminae, the transverse and spinous processes, and the facet joints. Together, they form a protective canal for the cervical spinal cord and its nerve roots. The anterior part of each vertebra is made up of the thick bony body, which is linked to the body above and below by intervertebral discs. These discs help provide stability and shock absorption to the spine.

Functionally, the cervical spine supports the head, and protects the neural elements as they come from the brain and form the spinal cord. Therefore, injuries or disorders affecting the neck can also affect the underlying spinal cord and have potentially catastrophic consequences. Here, we will illustrate how to perform a thorough neck examination, in a sequential manner, to assess the stability and the physical state of the cervical spine.

Let’s start with inspection. Before you begin, perform proper hand hygiene. Request the patient to remove enough clothing so that the entire neck and upper shoulders are exposed. Look at the neck from behind starting from the base of the skull and down to the upper back. There should be near perfect symmetry and the head should sit in the midline. Tilting to one side may suggest muscle spasm, such as with torticollis.

Observe the midline spinous processes, and the form and bulk of the paraspinous muscles that surround the midline. There may be asymmetry here due to a spasm related to a trauma or due to the overuse injury involving these powerful neck muscles. Inspect the neck from the lateral side and observe the smooth lordotic curve. A loss of this curve is commonly seen as a non-specific reaction to any kind of cervical injury or pain. A more dramatic straightening of the cervical spine can be seen with ankylosing spondylitis.

After inspection, proceed to palpation, which should be done using the tips of the index and middle fingers to check for tenderness, muscle spasm, or a subtle underlying bony deformity. Important areas that should be palpated include: the spinous processes, the posterior facet joints, and the paraspinous muscles.

Begin with the spinous processes. Start palpating at the base of the skull. The first process to be felt is that of the C2 vertebra. Then palpate downwards inspecting each process until you reach the C7 vertebra, which is the most prominent of all the spinous processes. Check for tenderness or an abrupt step off from one process to the next. Tenderness may suggest a contusion or underlying fracture, while a step off may indicate a fracture or ligament disruption.

Next, move your fingers a few centimeters to the left or right of each spinous process to palpate the posterior facet joints. Tenderness over these joints may suggest osteoarthritis or a fracture. Lastly, palpate the paraspinous muscles, along either side of the spinous processes that overlie the facet joints. Tenderness or spasm can be due to muscle injury or involuntary reaction to pain coming from the underlying cervical spine.

The next step is to assess the neck’s range of motion. This can be done either actively or passively. Following are the important movements that one should evaluate.

First is forward flexion, ask the patient to move the chin to their chest. The normal range of flexion is about 45°. Next, ask the patient to extend their neck by pulling their chin all the way up as much as they can. The normal range of this motion is close to 55°. Subsequently, assess twisting – instruct the patient to first put their chin on one shoulder and then the other and compare between the sides. The normal range of rotation is about 70° in each direction. Lastly, assess side bending by asking the patient to put their ear on one shoulder, then to the other and compare between the sides. The normal range for this motion is 40° each way.

After range of motion tests, let’s review how to assess muscle strength for the neck region. This involves the range of motion maneuvers, but against resistance applied by the examiner. This is mainly done to evaluate for pain or weakness.

Starting with forward flexion – ask the patient to touch their chin to their chest, while you resist by placing your hand on their forehead. This tests both the sternocleidomastoid muscles. Next, ask the patient to raise their chin in the air while you provide resistance by placing your hand on the back of their head. This maneuver assesses the posterior paraspinous muscles. Subsequently, evaluate the strength required for neck twisting by placing your hand on either side of the patient’s chin to resist the motion. This again evaluates the left and right sternocleidomastoid muscles. Finally, assess the strength of muscles involves in side bending by placing your hand on the either side of the patient’s head to resist the movement. This tests the left and right scalene muscles.

Now lets discuss a couple of tests performed to evaluate nerve root impingement caused by abnormal disc or bone.

The first impingement test is called the Spurling’s test, also known as the Atlanto-axial compression test. Have the patient rotate their head to one side and apply an axial load to the top of head while the neck is twisted. Radicular pain to the ipsilateral shoulder and arm suggests cervical nerve root irritation.

Second is the Forward Flexion test. Instruct the patient to turn their head onto one side, then passively forward flex their neck, and ask them if they feel any pain. Radicular pain to ipsilateral arm suggests disc impingement on a cervical nerve root.

The last part of the neck exam involves performing some motor and sensory testing of the nerves exiting the cervical spinal canal. A loss of function observed during these tests could be due to nerve injury or a dysfunction related to a herniated disc.

Start by testing the sensory response. Explain to the patient that you are going to lightly touch them with your fingertips to evaluate changes in sensation. Assess the following areas, while comparing sides: lateral neck – to test the C4 nerve root, deltoid muscle, medial arm and elbow – for the C5 and T1 dermatome, and lastly the hands, specifically the thumb, middle and pinky fingers – to test the radial, median and ulnar nerves, respectively. Next, perform maneuvers assessing strength of certain surrounding muscles to test neurological functioning. This includes shoulder abduction with elbows bent for the deltoid muscle, elbow flexion for biceps, elbow extension for triceps, and wrist flexion and extension for wrist flexor and extensors, respectively.

The last of the neurological tests involve testing tendon reflexes using a reflex hammer. To test Biceps tendon reflex, place your thumb over the distal biceps tendon and tap briskly against it. Lack of reflex suggests dysfunction of the C5 nerve root. Then tap briskly over the distal triceps tendon to test the triceps tendon reflex. Lack of reflex here suggests dysfunction of the C7 nerve root. This concludes the neck exam.

You’ve just watched JoVE’s demonstration of a complete neck exam. This assessment should begin with inspection to check for any lack of symmetry, followed by palpation, looking for tender spots or an abnormal step off between the vertebrae. Next, range of motion is assessed, first actively and then against resistance to assess muscle strength. Subsequently, one should evaluate for nerve root impingement caused by abnormal disc or bone, using the Spurling’s and the Forward Flexion test. This is followed by the examination for sensory or motor loss in the cervical nerve roots. Remember, the cervical spine is also a common source of radicular pain in the shoulder. For these reasons, the neck should be evaluated as a routine part of every shoulder exam. As always, thanks for watching!