Specifications

This tells you that to stand upright and carry the 50 N load in the right hand, the model is using 4.00e-001

= 40% of its maximum voluntary contraction. This means that the relative load of the muscle with the

highest activity in the system is 40% of the muscle's strength. Even though one number is a very simplified

way of regarding a system with hundreds of muscles, there are good mathematical reasons why this

particular number is a good measure of the human effort of a particular task.

You can obtain more detailed information if you expand the Model branch in the tree view on the left hand

side of the bar diagram. Going down through Model -> HumanModel -> Right -> ShoulderArm -> Mus gives

you a long list of all the muscles in the right shoulder and arm. A bit down this list you can find the rotator

cuff muscle supraspinatus, which tends to be one of the sources of rotator cuff pain. Like many of the

muscles in the model, the anatomical muscle supraspinatus is divided into several mechanical branches to

account for fibers going in different directions and attaching to different bones. If you open op

Supraspinatus_3 you can find the property Fm inside. Click it once, and you should see a new bar illustrating

the force in this muscle element similar to the picture below.