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A B M P m e m b e r s e a r n F R E E C E a t w w w. a b m p . c o m / c e b y r e a d i n g M a s s a g e & B o d y w o r k m a g a z i n e 87 Cervical Rib Variation If there is an osseous extension of the transverse process or a true cervical rib, it will take up space in the thoracic outlet region. Neurological and vascular structures must course over the top of the cervical rib before making their way under the clavicle and down the arm. Because the cervical rib sits above the first rib, the neurovascular structures get bowstrung across the top of the cervical rib as they course through this region. This is especially true with the brachial plexus fibers that originate at the T1 nerve root, because they already sit below the first rib. Because this neurovascular compression problem is the result of a bony obstruction in the thoracic outlet region, there is very little massage can do to address this problem. Yet, learning about the presence and existence of cervical ribs is important for massage therapists because many may attempt to perform vigorous work on what appear to be very hard scalene muscles when, in effect, they are actually pressing on a cervical rib structure. If pathological symptoms continue to persist with a cervical rib TOS variation, surgery may be suggested. The surgical procedure usually involves removing the bony extension from the C7 transverse process. In many cases, immediate relief will be felt as the obstruction is no longer obscuring the path of the neurovascular structures. The scalene triangle. Image is from 3D4Medical's Complete Anatomy application. 2 Components of the brachial plexus. Image is from 3D4Medical's Complete Anatomy application. T1 nerve root Inferior trunk Medial cord scalene triangle. The first rib forms the base of the triangle. Previously, I've made several references to a cervical rib. This term may seem odd because the ribs are all located in the thoracic region. However, there is an anatomical anomaly that occurs in a small percentage of the population. As the skeleton matures, lateral aspects of the C7 transverse process that are ossified are eventually reabsorbed and the transverse process assumes its normal shape. However, sometimes this does not occur and an elongated transverse process is produced. In some cases, the elongation of the transverse process extends all the way down and has fibrous connections with the first rib (Image 4, page 88). This is called a cervical rib. It is estimated that somewhere between one half and 2 percent of the population have cervical ribs, and, for some reason, they appear more frequently in women. 1 These anatomical structures all play a role in one or more of the various TOS pathologies. While TOS is generally described by the compression location, it may also be described by what type of tissue is involved. Consequently, you may see any of these different variations of TOS described: • Arterial (A-TOS): compression of the subclavian artery or any of its distal branches in the cervical and upper thoracic region. • Venous (V-TOS): compression of the subclavian vein or any of its distal branches in the cervical and upper thoracic region. • True Neurogenic (TN-TOS): compression of any of the branches of the brachial plexus without arterial or venous involvement. Numerous cases involve more than one of these at the same time. For example, you could have arterial and neurological compression but not venous (which is common). You could have arterial and venous compression that does not have a neurological component. The compression is considered neurovascular if it involves not only nerves, but at least some arterial or venous compression at the same time. DESCRIPTION BY LOCATION The most common method for classifying TOS variations is by location. There are four potential variations/regions where neurovascular compression may occur, and each is discussed below. As a general rule, the symptoms from each of these four variations can be similar with a few exceptions. The key symptoms to watch for in any one of these TOS variations include: • Atrophy of the thenar or hypothenar muscles of the hand. • Pain, aching, or numbness in the hand, fingers, or medial forearm (most commonly along the ulnar aspect of the hand and the C8 dermatome). • Paresthesia, although it is not as common from TOS as with carpal tunnel syndrome. • Loss of dexterity or grip strength. • Coldness or color changes in the hand (often confused with Raynaud's syndrome). Middle scalene Anterior scalene 3