Description KineMat is a set of MATLAB function files written for the analysis
of three-dimensional kinematics. KineMat is intended for intermediate to
experienced MATLAB users.
KineMat provides the tools to build a motion analysis system tailored
and customized to your needs. A simple example on how to use this toolbox
is provided (demo1.m and demo2.m).
The KineMat toolbox can be used for two purposes:
1. 3D Reconstruction: KineMat allows the reconstruction of the
three-dimensional positions of markers seen in two or more cameras. Currently,
KineMat uses a DLT (direct linear transformation) procedure with 11 coefficients.
2. Motion Analysis: KineMat can be used to calculate transformation
matrices, Cardan angles (Joint Coordinate System), and finite helical axes
descriptors.
Remarks • Note that some of the functions are not written in a computationally
efficient way, and may well be rewritten/optimized for faster computing.
There is also the possibility to translate these MATLAB files into C by
using the "MATLAB to C" compiler.
• Transformation matrices (T) are expressed by 4x4 matrices containing
both the 3x3 rotation matrix (R) and the translation vector (d): T=[R,
d; 0, 0, 0, 1]
• All m-files can be used on all platforms for which MATLAB is available.
All m-file names are not longer than 8 characters and can therefore be
used in windows (3.x) environments.
Disclaimer Even though KineMat has been tested and used in the past, the authors
do not guarantee the correctness of these m-files. The use of this software
is at your own risk.
Usage Policies KineMat can be used free of charge. The authors however request proper
credit (citation or acknowledgments), if KineMat is used in publications
or in any other forms of communication.
Support KineMat is not supported! However, if you find errors, have suggestions,
concerns or additions to the existing library of m-files, contact either
Christoph Reinschmidt (Christoph.Reinschmidt@sulzer.com)
or Ton van den Bogert (bogert@bme.ri.ccf.org).
Acknowledgments KineMat was originally written for the analysis used in the thesis
of C. Reinschmidt. During that process, financial support was received
from the following institutions and agencies: the Swiss Federal Sports
Commission (ESK Switzerland), the Olympic Oval Endowment Fund of Calgary,
and adidas Research and Innovation.
The authors would also like to acknowledge the contribution of Ron Jacobs
who wrote the first version of "soder.m".
How to Start 1. Download kinemat.zip
(or kinemat.tar.Z)
and demo.zip
(or demo.tar.Z).
Extract the kinemat.zip-files into your MATLAB directory and create a directory
where demo.zip is extracted to.
2. Run demo1 and demo2 in MATLAB.
3. Print out (or look at) demo1.m and demo2.m which give you more insight
into the use of the various m-files used.
4. Look at the various m-files.
Short Description of the KineMat m-files A short description of the m-files contained in KineMat are given below.
A more detailed description can be found on the first lines of the respective
m-files (print out m-files or in MATLAB type "help functionname").
The appendix of my thesis also contains some additional information
regarding the analysis of intersegmental motion: append.doc
(winword file).
3D Reconstruction Tools:These set of programs allow
to reconstruct the three-dimensional positions of markers seen in two or
more cameras:
Calculates spatial position X,Y,Z, residuals of the reconstruction,
the cameras used from the DLT coefficients and the digitized marker coordinates
of the different cameras.
Motion Analysis Tools: These set of programs are used to calculate transformation matrices,
Cardan angles and corresponding translations (Joint Coordinate System),
and finite helical axes descriptors:
This program calculates the intersegmental motion (cardan
angles, and helical angles) between 2 segments. The required input is the
position of the markers in the anatomical coordinate system of segment
1 and segment 2, the position of these markers during the movement in segment
1 and segment 2, and the chosen sequence. The program outputs the Cardan
angles and helical angles (Woltring 1994, J. Biomechanics 27, 1399-1414).
Calculates the Cardan angles ( and translations) using sequence
xyz (first rotation about x fixed in first segment, y floating axis, and
last rotation about z fixed in the second segment).
This program calculates the local camera x,y coordinates
of a known point in 3D using the (known) DLT coefficients of that camera.
This program can for instance be used to plot finite helical axes into
stereo x-rays. (similar procedure as used in Blankevoort et al. (1990),
J.Biomechanics 21, 705-720).