Lumbar spine anatomy full#

It is usually readily palpable with full flexion of the neck. The spinous process of C6 is the last freely movable spinous process with flexion and extension of the neck. The spinous process of C3 is the smallest and can be found at the same horizontal plane as the greater cornua of the hyoid bone. The other cervical spinous processes are variably more difficult to palpate. In 60% to 70% of the population the vertebra prominens is the most prominent spinous process, whereas the spinous process of T1 is more evident in the other 30% to 40%. In the midline below the spinous process of the axis, the second prominent palpable structure is the spinous process of C7 or the vertebra prominens. 1-2), although according to Oliver and Middleditch (1991) the posterior tubercle of C1 may be palpable in some people between the EOP and the spinous process of C2. The spinous process of the axis is the first readily palpable bony structure in the posterior midline below the EOP (see Fig. 1-2 Palpable landmarks of the lateral neck. These curves are covered in more detail in Chapter 2.įIG. Normally there is no lateral deviation of the spinal column, but such curvature is known as scoliosis when present. In the cervical and lumbar regions the spine is anteriorly convex (lordotic), and in the thoracic and sacral areas it is posteriorly convex (kyphotic). In the adult the vertebral column has several visible normal curves. When the patient’s head is flexed, the spinous processes of C7 and T1, and often C6, usually are seen easily. The spinous process of T1 often is visible also and actually is the most prominent spinous process in 30% to 40% of the population. The spinous process of C7 (the vertebra prominens) usually is visible in the lower cervical region. These muscle masses are responsible for the deepening of the median furrow in this region.īesides these muscles, several bony landmarks usually are visible in the region of the back. The erector spinae muscles form two large longitudinal masses in the lumbar region that extend approximately a handbreadth (10 cm) laterally from the midline. Between the trapezius medially and the latissimus dorsi laterally, the inferior angle of the scapula may be seen at approximately the level of the T7 spinous process. This muscle is especially noticeable when the upper extremity is adducted against resistance. The latissimus dorsi, extending from the region of the iliac crest to the posterior border of the axilla, forms the lateral border of the lower thoracic portion of the back. Its upper fibers form the “top of the shoulder,” where the neck laterally blends into the thorax. The trapezius is a large, flat, triangular muscle that originates in the midline from the EOP to the spinous process of T12 and inserts laterally onto the spine of the scapula. Several muscles are commonly visible in the back region.

Lumbar spine anatomy