CHAPTER 10 Structure and Function of the Wrist and Hand Complex
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Taut digital extensors
A Slack extensor digitorum
Figure 10.20 Tenodesis. (A) Tenodesis action opens the hand when the wrist is flexed. (B) Active wrist extension creates passive tension in digital flexors that flexes the fingers without effort from the person.
B
Active extensor carpi radialis brevis
Figure 10.21 (A) Palmar view of the flexor tendon pulley system showing the tunnels formed by the flexor retinaculum and the transverse carpal ligaments (TCLs). The pulleys and tendon sheaths have been removed on the fourth digit to display the relationship between the flexor digitorum profundus (FDP) as it passes through the split flexor digitorum superficialis (FDS). The annular pulleys are labeled A1 through A5; the cruciate pulleys are labeled C1 through C3. (B) Side view of the annular pulleys. (From Starkey C, Brown D. Examination of Orthopedic & Athletic Injuries, 4th ed. Philadelphia, PA: F. A. Davis Company, 2015, p. 740, with permission.)
