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| The Surgical Technologist | DECEMBER 2021 544 include a gritty or numb sensation in the fingers, grip and pinch weakness, and diminished finger dexterity with a his- tory of dropping objects. 4 CTS usually occurs only in adults. Women are three times more likely than men to develop carpal tunnel syn- drome. 3 Symptoms often are experienced during pregnancy and typically relieved post-delivery. Workplace factors may contribute to existing pressure on or damage to the median nerve. The risk of developing CTS is not confined to people in a single industry or job but may be more reported in those performing assembly line work—such as manufactur- ing, sewing, finishing, cleaning, and meatpacking. 3 D I A G N O S I N G C A R P A L T U N N E L S Y N D R O M E The hand consists of 27 bones. Eight carpal bones: scaphoid, capitate, trapezoid, trapezium, lunate, hamate, triquetrum, and pisiform; five metacarpal bones; and 14 finger bones. Each finger has a proximal, middle, and distal phalanx. Except for the thumb, it does not have a middle phalanx. The carpal tunnel is bordered dorsally by the concave arch of the carpus and volarly by the transverse carpal ligament (TCL). The carpal tunnel houses the median nerve and nine flexor tendons. The flexor pollicis longus tendon, four flexor digitorum profundus tendon slips, and four flexor digitorum superficialis tendon slips. 4 The following are the six diag- nostic criteria for CTS: nocturnal numbness, numbness and tingling in the median nerve distribution, weakness and/ or atrophy of the thenar muscles, Tinel’s sign, Phalen’s sign, and loss of two-point discrimination. 1 Tinel’s sign is elicited by gently tapping on the median nerve at the carpal tun- nel. A positive response is noted if the patient describes an electrical shock sensation in the median nerve distribution. 4 Phalen’s test is performed by placing the patient’s elbow on an examination table and allowing the wrist to flex for 60 seconds. If the patient reports paresthesia in the median nerve distribution, this test is considered positive. 4 Durkan’s median nerve compression test involves direct compression of the median nerve at the carpal tunnel for 30 seconds. This test is considered positive if the patient reports numbness Carpal tunnel syndrome occurs when the median nerve, which runs from theforearmintothepalmof thehand, becomes pressed or squeezed at thewrist.