An investigation of muscle lines of action about the hip: a centroid line approach vs the straight line approach
J Biomech. March 1975;8(2):103-110
Affiliations
1Department of Anatomy, University of Nebraska Medical Center, Omaha, Nebraska 68105. U.S.A.
2Department of Engineering Mechanics, University of Nebraska, Lincoln, Nebraska 68508, U.S.A.
Abstract
A comparison is presented of representing skeletal muscles as centroid lines and as straight lines in force analysis of musculoskeletal systems. Three muscles crossing the hip joint are chosen for examination; the gluteus medius, the rectus femoris, and the sartorius muscles. A procedure for obtaining the centroid line representation is presented. An imbedded coordinate system for each major anatomical segment defined by bony landmarks serves as a local reference frame for geometric data. Centroid line data are displayed graphically for two cadaver specimens. Tabulated data demonstrate numerical differences between representing muscles' lines of action as centroid lines and as straight lines. Results of the comparison are discussed along with the underlying assumptions for the centroid comparison.