A novel method to replicate the kinematics of the carpus using a six degree-of-freedom robot.
Understanding the kinematics of the carpus is essential to the understanding and treatment of wrist pathologies. However, many of the previous techniques presented are limited by non-functional motion or the interpolation of points from static images at different postures. We present a method that has the capability of replicating the kinematics of the wrist during activities of daily living using a unique mechanical testing system. To quantify the kinematics of the carpal bones, we used bone pin-mounted markers and optical motion capture methods. In this paper, we present a hammering motion as an example of an activity of daily living. However, the method can be applied to a wide variety of movements. Our method showed good accuracy (1.0-2.6°) of in vivo movement reproduction in our ex vivo model. Most carpal motion during wrist flexion-extension occurs at the radiocarpal level while in ulnar deviation the motion is more equally shared between radiocarpal and midcarpal joints, and in radial deviation the motion happens mainly at the midcarpal joint. For all rotations, there was more rotation of the midcarpal row relative to the lunate than relative to the scaphoid or triquetrum. For the functional motion studied (hammering), there was more midcarpal motion in wrist extension compared to pure wrist extension while radioulnar deviation patterns were similar to those observed in pure wrist radioulnar deviation. Finally, it was found that for the amplitudes studied the amount of carpal rotations was proportional to global wrist rotations.
Biomechanics & Neuromotor Labs, Sansom Institute for Health Research, School of Health Sciences, University of South Australia, Australia. Electronic address: francois.fraysse@unisa.edu.au.
François
F
Fraysse
Biomechanics & Implants Research Group, The Medical Device Research Institute, School of Computer Science, Engineering & Mathematics, Flinders University, Australia.
John J
JJ
Costi
Biomechanics & Implants Research Group, The Medical Device Research Institute, School of Computer Science, Engineering & Mathematics, Flinders University, Australia.
Richard M
RM
Stanley
School of Mechanical Engineering, University of Adelaide, Australia.
Boyin
B
Ding
Department of Orthopaedics & Trauma, Royal Adelaide Hospital, Australia.
Duncan
D
McGuire
Department of Orthopaedics & Trauma, Royal Adelaide Hospital, Australia.
Kevin
K
Eng
Department of Orthopaedics & Trauma, Discipline of Anatomy and Pathology, University of Adelaide, Australia.
Gregory I
GI
Bain
Biomechanics & Neuromotor Labs, Sansom Institute for Health Research, School of Health Sciences, University of South Australia, Australia.
Dominic
D
Thewlis
D000328:Adult; D001696:Biomechanical Phenomena; D002348:Carpal Bones / Q000502:physiology*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D009038:Motion; D009068:Movement; D011187:Posture; D016059:Range of Motion, Articular; D012371:Robotics; D014955:Wrist Joint / Q000502:physiology*; D055815:Young Adult
Carpal bones; Dart thrower's motion; Ex vivo; Hammering; Wrist kinematics