Storming Media: Pentagon Reports and DocumentsPentagon Reports: Fast. Definitive. Complete.     
New Account »
Forgot Password?
Advanced Search »

MedicineAnatomy and Physiology

Instantaneous Axis of Rotation for Continuous Human Knee Motion

Authors: Steven Parks; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
 
Abstract: Previous studies of human knee motion are based on finite rotation data collected using large rotation steps varying from 5 to 30 degrees. In some cases this rotation data is used to develop axes of rotation for the joint. For such analysis, the rotation axis developed may be significantly different from the joint's instantaneous axis of rotation because, in general, the axis of rotation developed using finite rotation steps only closely approximates the true instantaneous axis of rotation if the step size is small. For the current study, a device has been developed to record high frequency (15 Hz) rotation and translation data of the femur and tibia during knee flexion. Kinematic constraint equations have been developed to analyze the six degree of freedom rotation and translation data to obtain an accurate approximation to the instantaneous axis of rotation. Four cadaveric knees were II analyzed with all ligaments intact. Motion characteristics common to all knees were identified. The most obvious characteristic, internal tibial rotation, was related to the initial varus/valgus orientation of each knee. The anterior cruciate ligaments (ACL) of these same knees were subsequently severed, the knees were measured, and the motion analyzed. Differences in the motion characteristics of each knee were detected alter the ACL was cut.

Limitations: APPROVED FOR PUBLIC RELEASE
Description: Master's thesis
Pages: 128
Report Date: JUN 97
Report Number: A693333
Keywords relating to this report:
*BIOMECHANICS
*KNEE_ANATOMY_
*ROTATION
AXES
BONES
HUMANS
JOINTS
LEGS
MOTION
PHYSIOLOGY
THESES
THREE DIMENSIONAL
THREE DIMENSIONAL FLOW
TIBIA
Adobe PDF - $28.95
Printed Format - $46.95
Please check the box for the format you wish to order.
Shipping Terms
About Electronic Delivery

Email This Abstract