Skip directly to search Skip directly to A to Z list Skip directly to page options Skip directly to site content

NIOSHTIC-2 Publications Search

Search Results

Modeling of the muscle/tendon excursions and moment arms in the thumb using the commercial software Anybody.

Authors
Wu-JZ; An-KN; Cutlip-RG; Andrew-ME; Dong-RG
Source
J Biomech 2009 Feb; 42(3):383-388
NIOSHTIC No.
20035091
Abstract
A biomechanical model of a thumb would be useful for exploring the mechanical loadings in the musculoskeletal system, which cannot be measured in vivo. The purpose of the current study is to develop a practical kinematic thumb model using the commercial software Anybody (Anybody Technology, Aalborg, Denmark), which includes real CT-scans of the bony sections and realistic tendon/muscle attachments on the bones. The thumb model consists of a trapezium, a metacarpal bone, a proximal and a distal phalanx. These four bony sections are linked via three joints, i.e., IP (interphalangeal), MP (metacarpophalangeal) and CMC (carpometacarpal) joints. Nine muscles were included in the proposed model. The theoretically calculated moment arms of the tendons are compared with the corresponding experimental data by Smutz et al. [1998. Mechanical advantage of the thumb muscles. J. Biomech. 31(6), 565-570]. The predicted muscle moment arms of the majority of the muscle/tendon units agree well with the experimental data in the entire range of motion. Close to the end of the motion range, the predicted moment arms of several muscles (i.e., ADPt and ADPo (transverse and oblique heads of the adductor pollicis, respectively) muscles for CMC abduction/adduction and ADPt and FPB (flexor pollicis brevis) muscle for MP extension/flexion) deviate from the experimental data. The predicted moment potentials for all muscles are consistent with the experimental data. The findings thus suggest that, in a biomechanical model of the thumb, the mechanical functions of muscle-tendon units with small physiological cross-sectional areas (PCSAs) can be well represented using single strings, while those with large PCSAs (flat-wide attachments, e.g., ADPt and ADPo) can be represented by the averaged excursions of two strings. Our results show that the tendons with large PCSAs can be well represented biomechanically using the proposed approach in the major range of motion.
Keywords
Biomechanics; Biomechanical-modeling; Bone-structure; Carpal-tunnel-syndrome; Cumulative-trauma-disorders; Cumulative-trauma; Ergonomics; Laboratory-techniques; Medical-research; Motion-studies; Models; Muscle-physiology; Muscle-stress; Musculoskeletal-system-disorders; Occupational-health; Physiological-factors; Physiological-fatigue; Physiological-measurements; Physiological-response; Physiological-testing; Repetitive-work; Author Keywords: Thumb; Kinematics; Muscle-tendon excursion; Moment arm; Simulations
Contact
John Z. Wu, CDC, NIOSH, 1095 Willowdale Rd, MS-2027, Morgantown, WV 26505
CODEN
JBMCB5
Publication Date
20090209
Document Type
Journal Article
Email Address
jwu@cdc.gov
Fiscal Year
2009
NTIS Accession No.
NTIS Price
Issue of Publication
3
ISSN
0021-9290
NIOSH Division
HELD
Source Name
Journal of Biomechanics
State
WV
TOP