data = KINETICS_DATA(data,settings,filt) will compute inverse dynamics on
Plugingait (PiG) or Oxford Foot model (OFM) marker sets
ARGUMENTS
data ... Zoo data containing all vicon 'bone' outputs
settings ... Settings control (struct) with the following fields:
'segpar'(string). Default, 'segmentParameters' (currently only choice)
'graph' (boolean). Default, false
'city' (string). Default, 'standard' sets grav const, see g
'filt' (boolean). Default, false. Don't filter intermediate calculations
'comp' (boolean). Default, true. Compares agains Vicon output (if available)
filt Filter settings for GRF (struct). Default, see setFilt
RETURN
data ... Zoo data with joint kinetics and related quantities appended
NOTES
- This function computes all force and moments based on the method proposed by
Vaughan (The Dynamics of Human Gait, 1999).
- Joint Power are computed according to Kwon (eq 7)
http://www.kwon3d.com/theory/jtorque/jen.html
- Joint Forces are expressed in the distal segment reference frame
according to Vicon and not using the Grood and Suntay axes as proposed by Vaughan.
- Only midfoot (OFM only), ankle, knee, and hip kinetics are computed here. However,
pelvis segment embedded axes are included since they are required for hip power calcs
- For best agreement of Force values with Vicon all segments were given a mass of 0kg
(please see force subfunctions)
GENERAL ALGORITHM (see Vaughan for more details)
1) Calculate the forces at the proximal joint using Newton's 2nd law (linear form)
2) Calculate the moment arms, proximal and distal, between the force application
point and the segment centre of gravity.
3) Calculate the residual moment acting on the segment.
4) Calculate the rate of change of angular momentum for the segment
5) Calculate the resultant joint moment, first in the xyz system using
Newton's 2nd law (angular form), then in XYZ system.
6) Convert the joint force and moment from the XYZ system to a body-based system.
See also kinematicsPiG_data, makebones, prepfp_data