Moment arm and force-generating capacity of the extensor carpi ulnaris after transfer to the extensor carpi radialis brevis.

Content Provider	Semantic Scholar
Author	Herrmann, Alice Delp, Scott L.
Copyright Year	1999
Abstract	Tendon transfers to the extensor carpi radialis brevis (ECRB) are often performed to augment wrist extension. This study was conducted to analyze how transfer of the extensor carpi ulnaris (ECU) to the ECRB affects the moment arms, force-generating capacity, and moment-generating capacity of the ECU over a range of wrist flexion-extension. A graphics-based computer model was developed from anatomic measurements of the muscle-tendon paths before and after transfer. This model calculates the lengths and moment arms of the muscles over a range of wrist flexion-extension and represents the muscles' force-generating characteristics from previous measurements of their physiologic cross-sectional areas, fiber lengths, and pennation angles. Analysis of the computer model revealed that the maximum isometric extension moment of the ECU at the neutral wrist position increased from 0.50 N-m to 1.72 N-m after transfer to the ECRB. The deviation moment shifted from 2.72 N-m ulnar deviation to 1.42 N-m radial deviation. The extension moment generated by the ECU varied more with wrist flexion angle after transfer due to its broadened operating range on the muscle force-length relationship. The simulations highlight the need for proper intraoperative tensioning of the ECU to maximize the force-generating potential of the transferred muscle over the functional range of motion.
Starting Page	2128
Ending Page	2132
Page Count	5
File Format	PDF HTM / HTML
Alternate Webpage(s)	http://nmbl.stanford.edu/publications/pdf/Herrman1999.pdf
Alternate Webpage(s)	http://web.stanford.edu/group/nmbl/publications/pdf/Herrman1999.pdf
PubMed reference number	10509289v1
Volume Number	24
Issue Number	5
Journal	The Journal of hand surgery
Language	English
Access Restriction	Open
Subject Keyword	Alveolar rhabdomyosarcoma Extensor carpi ulnaris muscle structure Structure of extensor carpi radialis brevis muscle Tendon structure Tissue fiber
Content Type	Text
Resource Type	Article