Attached model is a modification from the MoCapModel; FullBody example in version 6.0.5.(4379). Currently I’m using the model to estimate joint loading and muscle activity during tasks involving movement of the right arm.
I’ve compared the maximum estimated muscle activity to the maximum measured EMG and the model seems to underestimate the needed activity heavily (results are attached as PDF). The reason why seems unclear to me at the moment, thus I would like to have some professional help. As a remark, the motion the simulation model performs is not accurate, as the pelvis moves from the seat which did not occur in the experiments. Therefor it needs more constraints in the vertical direction and would like to know how this should be implemented.
Included in the Input folder you will find a Reaching Far Upper Left (RFUL, known as Contralateral), Right (RFUR, known as Ipsilateral) and Shoulder Ab- Adduction (SAA) movement recorded to .c3d file. Also, I’ve attached data analysis of the estimated joint loading and muscle activity (MA) and measured EMG (ME) in these three movements (C1_RFUR.mat, C1_RFUL.mat, C1_SAA.mat) as ‘C1_EMG.zip’ in the first folder. Six muscles are included; Biceps, Triceps, Deltoid, Trapezius, Pectoralis major and Latissimus Dorsi. Also, the GlenoHumeral Ab-Adduction, Flex-Extension and Rotation, and Elbow Flex-Extension can be found in the MA structure. Subject C1 equals to row 12 in this structure. When opening for example the Biceps, the structure shows ‘mp’, ‘pa’ and ‘mt’. The first parameter ‘mp’ shows the averaged activity of all Muscle Parts over time which correspond in the model to the location of the measured EMG. ‘pa’ means separate muscle Parts Activity and ‘mt’ is the Maximum activity of ‘mp’ and its corresponding Time. This last parameter ‘mt’ is used to compare to the measured EMG (ME), which has the same structure. Thus, I compare for example the maximum muscle activity MA.Bic.mt (first value) to ME.Bic.mt (first value) in all conditions. If that seems to be correct I also check the averaged activity pattern per muscle using ‘mp’. Individual muscle parts ‘pa’ has not been used yet. Multiple subjects have been investigated leading to the results in the reference (PDF).
Thanks in advance for the help.