SummaryThe human spinal column has evolved to a form that allows for efficient functioning in a highly technological society. According to the concept of sagittal spinal balance, the alternating curves of cervical and lumbar lordosis and thoracic and sacral kyphosis enable the head to be positioned over the trunk and pelvis. This form permitsHomo sapiensto assume a biped, upright position, with the upper limbs free for other tasks. Sagittal imbalance represents departure from this ideal form. Imbalance involving any of the constituent parts of the spinal column is problematic; despite mechanisms of spinal compensation, imbalance can affect form and function. Cervical kyphosis, a reversal of the normal lordosis, may represent the most disabling of these imbalances, for it can cause postural difficulties, pain, or neurologic deficit. The consequences of sagittal imbalance, especially “flatback deformity,” resulting from spinal instrumentation procedures, are well recognized. Similarly, structural deformities of the cervical spine cause pain related to increased energy expenditure of the posterior cervical musculature, can result in accelerated degenerative changes of adjacent segments of the spine, and impair the ability to maintain a horizontal line of view. A discussion regarding the etiology and treatment of this condition follows.