Hello everyone. I have collected marker position data and ground reaction force during walking. How to calculate joint angle, joint force and joint moment? Is there any MATLAB code? Thank you.
Hi Chuan He .
Our MoveHuman Sensor software in biomechanical lab, makes it automatically and express it in excel paper pluss the results about cinetic and cinematic variables.
Best regards
There is an assumption that one is dealing with open chain kinematics -levers- and that inverse dynamics can be used to calculate forces. If the body uses closed chain kinematics (CKC),
Levin, Stephen, Susan Lowell de Solórzano, and Graham Scarr. "The Significance of Closed Kinematic Chains to Biological Movement and Dynamic Stability." Journal of bodywork and movement therapies (2017).
then the use of inverse dynamics would be inappropriate. Even if only some of the joints are part of CKCs, it would seriously affect calculations.
Dear Stephen M Levi,
Thank you for your answer! Does the stance limb use closed chain kinematics while the swing limb open chain kinematics during walking?
I just want to calculate joint angle, joint force, joint moment and joint power using inverse dynamics in gait analysis. I have collected marker position data and ground reaction force during walking. Is there any MATLAB code for me? Thank you.
Best regards,
Chuan
I am afraid you are out of luck. The hamstrings, quads and gastrocs are clearly involved in closed kinematic chains (CKC). The tibialis anterior crosses the ankle and into the foot and as it crosses several joints it is also probably part of a closed kinematic chain. In fact, any muscle that crosses more than one joint is likely part of a CKC. (There are references going back to the 1890s in our article). A CKC can be locked or moved with one muscle while the other muscles can remain isometric and isotonic, (which are unreadable by EMGs), so you can't tell if they are tense or not, so swinging or standing, CKCs must be considered in modeling and calculations.
Dear Stephen M Levi,
Thank you for your detailed explanation! When CKCs being considered, the results will be more accurate while calculations may be more complicated. Now I first need to learn how to do inverse dynamics calculations. If I need more accurate results in the future, I will definitely consider your suggestion. Thank you again!
Best wishes,
Chuan
I find a free powerful MATLAB toolbox 3D Kinematics and Inverse Dynamics https://ww2.mathworks.cn/matlabcentral/fileexchange/58021-3d-kinematics-and-inverse-dynamics. It really helps.
" This toolbox contains all the Matlab functions for 3D kinematics and inverse dynamics computation applied to the lower and upper limb. The right lower (upper) limb is considered for sign conventions.
For instance, this toolbox includes functions for multibody optimisation with different joint models (noted N, S, U, and H for no model, spherical, universal and hinge models) and functions for inverse dynamics with different methods: vector and Euler angle (noted VE), homogenous matrix (noted HM), wrench and quaternion (noted WQ), generalized (i.e., natural) coordinate (noted GC). "
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