title: Effect of skin movement on the analysis of hindlimb kinematics during treadmill locomotion in rats.
abstract: In rat gait kinematics, the method most frequently used for measuring hindlimb movement involves placing markers on the skin surface overlying the joints being analyzed. Soft tissue movement around the knee joint has been considered the principle source of error when estimating hindlimb joint kinematics in rodents. However, the motion of knee marker was never quantified, nor the different variations in joint angle associated with this gait analysis system. The purpose of this study was two-fold. The first purpose was to expand upon the limited pool of information describing the effect of soft tissue movement over the knee upon the angular positions of the hip, knee and ankle of rats during treadmill locomotion. Secondly, it was a goal of this study to document the magnitude of the skin displacement when using markers that were attached superficially to the knee joint. This was examined by comparing the hindlimb kinematics in sagittal plane during treadmill locomotion determined from the marker attached to the knee and when the knee position was determined indirectly by computer analysis. Results showed that there is a considerable skin movement artefact which propagates to knee joint position and hindlimb kinematics estimates. It was concluded that these large errors can decrease data reliability in the research of rat gait analysis.
authors.affiliation: Department of Engineering, CETAV, University of Trás-os-Montes e Alto Douro, P.O. Box 1013, 5001-911 Vila Real, Portugal.
authors.forename: Vitor M
authors.initials: VM
authors.lastname: Filipe
authors.forename: José E
authors.initials: JE
authors.lastname: Pereira
authors.forename: Luís M
authors.initials: LM
authors.lastname: Costa
authors.forename: Ana C
authors.initials: AC
authors.lastname: Maurício
authors.forename: Pedro A
authors.initials: PA
authors.lastname: Couto
authors.forename: Pedro
authors.initials: P
authors.lastname: Melo-Pinto
authors.forename: Artur S P
authors.initials: AS
authors.lastname: Varejão
mesh_terms: D000818:Animals; D016477:Artifacts; D001696:Biomechanical Phenomena / Q000379:methods*; D005080:Exercise Test; D005260:Female; D006614:Hindlimb / Q000502:physiology*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007596:Joints / Q000502:physiology*; D008124:Locomotion / Q000502:physiology*; D009068:Movement / Q000502:physiology; D010781:Photography / Q000379:methods; D016059:Range of Motion, Articular / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012879:Skin Physiological Phenomena; D014741:Video Recording / Q000379:methods