title: Measurement of varus-valgus and internal-external rotational knee laxities in vivo--Part II: relationship with anterior-posterior and general joint laxity in males and females.
abstract: We examined sex differences in general joint laxity (GJL), and anterior-posterior displacement (ANT-POST), varus-valgus rotation (VR-VL), and internal-external rotation (INT-EXT) knee laxities, and determined whether greater ANT and GJL predicted greater VR-VL and INT-EXT. Twenty subjects were measured for GJL, and scored on a scale of 0-9. ANT and POST were measured using a standard knee arthrometer at 133 N. VR-VL and INT-EXT were measured using a custom joint laxity testing device, defined as the angular displacements (deg) of the tibia relative to the femur produced by 0-10 Nm of varus-valgus torques, and 0-5 Nm of internal-external torques, respectively. INT-EXT were measured during both non-weight-bearing (NWB) and weight-bearing (WB = 40% body weight) conditions while VR-VL were measured NWB. All laxity measures were greater for females compared to males except for POST. ANT and GJL positively predicted 62.5% of the variance in VR-VL and 41.8% of the variance in WB INT-EXT. ANT was the sole predictor of INT-EXT in NWB, explaining 42.3% of the variance. These findings suggest that subjects who score higher on clinical measures of GJL and ANT are also likely to have greater VR-VL and INT-EXT knee laxities.
authors.affiliation: Applied Neuromechanics Research Laboratory, Department of Exercise and Sport Science, University of North Carolina at Greensboro, 237B HHP Building, P.O. Box 26170, Greensboro, North Carolina 27402-6170, USA. sjshultz@uncg.edu
authors.forename: Sandra J
authors.initials: SJ
authors.lastname: Shultz
authors.forename: Yohei
authors.initials: Y
authors.lastname: Shimokochi
authors.forename: Anh-Dung
authors.initials: AD
authors.lastname: Nguyen
authors.forename: Randy J
authors.initials: RJ
authors.lastname: Schmitz
authors.forename: Bruce D
authors.initials: BD
authors.lastname: Beynnon
authors.forename: David H
authors.initials: DH
authors.lastname: Perrin
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena / Q000295:instrumentation; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000175:diagnosis; D007719:Knee Joint / Q000502:physiology*; D008297:Male; D012399:Rotation; D012727:Sex Characteristics