title: Modified kinematic technique for measuring pathological hyperextension and hypermobility of the interphalangeal joints.
abstract: Dynamic finger joint motion is difficult to measure using optical motion analysis techniques due to the limited surface area allowed for adequate marker placement. This paper describes an extension of a previously validated kinematic measurement technique using a reduced surface marker set and outlines the required calculations based on a specific surface marker placement to calculate flexion/extension and hyperextension of the metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints. The modified technique has been assessed for accuracy using a series of static reference frames (absolute residual error = ±3.7°, cross correlation between new method and reference frames; r=0.99). The method was then applied to a small group of participants with rheumatoid arthritis (seven females, one male; mean age = 62.8 years ± 12.04) and illustrated congruent strategies of movement for a participant and a large range of finger joint movement over the sample (5.8-71.1°, smallest to largest active range of motion). This method used alongside the previous paper provides a comprehensive, validated method for calculating 3-D wrist, hand, fingers, and thumb kinematics to date and provides a valuable measurement tool for clinical research.
authors.affiliation: Faculty of Health Sciences, University of Southampton, Southampton, SO17 1 BJ, UK. c.d.metcalf@soton.ac.uk
authors.forename: Cheryl D
authors.initials: CD
authors.lastname: Metcalf
authors.forename: Scott V
authors.initials: SV
authors.lastname: Notley
mesh_terms: D000368:Aged; D000465:Algorithms; D001696:Biomechanical Phenomena / Q000502:physiology; D005260:Female; D057918:Fiducial Markers; D005384:Finger Joint / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007592:Joint Diseases / Q000473:pathology / Q000503:physiopathology*; D007593:Joint Instability / Q000473:pathology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D016059:Range of Motion, Articular; D015203:Reproducibility of Results; D014741:Video Recording