title: Quantifying passive resistance to motion in the straight-leg-raising test on asymptomatic subjects.
abstract: The clinician needs an objective way to measure limb motion in the straight-leg-raising test. A biomechanical algorithm was used to quantify resistance to motion in 15 asymptomatic subjects. Measurements from a pendulum electrogoniometer and hand-held load cell were used to calculate a moment representing passive resistance to motion. After three measurement trials, significant increases in range of motion (4.7%) and moment (8.4%) occurred. Then, an isometric contraction-relaxation of the hip extensors produced a highly significant increase in motion (8.8%) but decrease in moment (< 14.3%). A third order polynomial fit of moment per angle stratified the sample into two groups according to their change in moment. Motion in group 1 increased 8.0%, and in group 2, 9.5%. However, group 1 had no change in moment whereas group 2 had a highly significant decrease in moment (22.9%). The measured change in resistance demonstrated that a simple biomechanical algorithm quantified properties in a clinical test that were not observed in range of motion alone.
authors.affiliation: Department of Biomechanics, Michigan State University-College of Osteopathic Medicine, East Lansing 48824-1316.
authors.forename: H M
authors.initials: HM
authors.lastname: Reynolds
authors.forename: M C
authors.initials: MC
authors.lastname: Beal
authors.forename: R C
authors.initials: RC
authors.lastname: Hallgren
mesh_terms: D000293:Adolescent; D000328:Adult; D000465:Algorithms; D000886:Anthropometry; D001696:Biomechanical Phenomena; D005260:Female; D006621:Hip Joint / Q000502:physiology*; D006801:Humans; D007537:Isometric Contraction; D007866:Leg / Q000502:physiology*; D008297:Male; D008433:Mathematics; D008875:Middle Aged; D016059:Range of Motion, Articular