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Forces and moments on the human leg in the frontal plane during static bipedal stance
Author(s) -
Macmahon Edward B.,
Carmines David V.
Publication year - 1992
Publication title -
journal of orthopaedic research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.041
H-Index - 155
eISSN - 1554-527X
pISSN - 0736-0266
DOI - 10.1002/jor.1100100622
Subject(s) - ground reaction force , orthodontics , coronal plane , knee joint , tibia , anatomy , joint (building) , biomechanics , moment (physics) , force platform , physical medicine and rehabilitation , geology , mathematics , medicine , physics , surgery , kinematics , structural engineering , engineering , classical mechanics
An experimental apparatus was assembled that permitted measurement of the vertical and lateral ground reaction forces as the hip is abducted, resulting in foot separations ranging from 0.25 to 71 cm, with the knee in 0° flexion. Twelve healthy volunteers (8 men and 4 women) were tested. The hip joint was located by means of center of rotation measurements on each subject's legs, and the location of the knee joint was determined using anatomical measurements. It was observed that the mediolateral force was nonzero and directed toward the body midline, even when the subject's feet were placed together. With the feet placed at shoulder width, the population mean mediolateral force was 3% of body weight. It was determined that simplifying assumptions based upon either “zero lateral force,” or “zero hip moment,” produced errors, when compared with our measured values, over various ranges of foot separation, with the zero hip moment assumption providing accuracy over a broader range. The inclination of the tibial plateau, with respect to the long axis of the tibia, that would produce minimal mediolateral shear at the knee is presented. Research and clinical applications of our results and techniques are discussed.