REIDER PART 2
51

Chaiter 8_Cervical and Thoracic Spine 311

Chaiter 8_Cervical and Thoracic Spine 311

Figurę 8-23. Palpation of the cricoid cartilage.

Muscle tests are normally conducted with the patient seated or standing. The patients ability to support the neck in the erect position is an indication that the mus-cles are at least strong enough to overcome the force of gravity. Ali strength testing should be done gently, with the examiner providing firm, controlled resistance. This avoids sudden uncontrollcd movements that could be pamfili or injurious.

Lateral Rotators

The sternocleidomastoid muscles function as both cer-vical rotators and flexors. Because they are innervated by the spinał accessory tierves_y a complete injury to one of these nerves would paralyze the corresponding sternocleidomastoid muscle. Isolated contraction of one sternocleidomastoid rotates the cervical spine, so that the patients chin points away from the contracting muscle: the left sternocleidomastoid produces right lateral rota-tion, and the right sternocleidomastoid produces left lateral rotation.

To test a given sternocleidomastoid muscle, the examiner places the palm of one hand on the opposite sidc of the patients head or face and instructs the patient to attempt to rotate the head to that side as strongly as possible. The tension in the sternocleidomastoid being tested should be quite visible (Fig. 8-24). Normally, the examiner should be unable to overcome the patienfs strength of rotation.

Figurę 8-24. A and B, Assessing right lateral rotation strength. (Arrows in B indicate tensed left sternocleidomastoid muscle.)