Humerus movement

The image is devided on three views of standing human body. Top area is top-down view. Left area is view onto back. Right area is side view. Depiction of humerus bone and radial nerve, while humerus is rotated in shoulder joint and ulna and radius is rotated in elbow joint.

The muscle names that would cover the view of the radial nerve if their visibility were not set high enough. Each muscle's minimum visibility should be at least 4%:

1. Backward Arm Movement with Visible Humerus Bone and Radial Nerve:

   • Layer Visibility: In order to clearly see the humerus bone and radial nerve, it's important to adjust the visibility of the following muscles:
     • Latissimus Dorsi: This muscle covers the upper back area and its visibility should be set at least 4% to allow the view of the humerus bone and radial nerve.
     • Trapezius: The trapezius muscle covers the upper back and neck. It should also be set to a minimum visibility of 4% to provide a clear view.
     • Deltoid: The deltoid muscle is at the shoulder and its visibility should be adjusted to a minimum of 4% to ensure visibility of the underlying structures.

2. Description of Movement:

   • Range of Motion: The starting position is with the arm hanging freely down, the hand alongside the body, and the palms facing the thighs.

   • Axis of Rotation: To move the arm backward away from the body until the palm is behind the back, an axis can be envisioned roughly from the spine towards the viewpoint of the model.

   • Movement:

     1. Position 1: The initial position is with the arm hanging freely down, the hand alongside the body, and the palms facing the thighs.
     2. Backward Arm Movement: The arm moves backward. In this step, the arm moves at a slight angle for comfortable and natural motion. The angle of rotation ranges approximately between 15 to 30 degrees.
     3. Bringing the Pinky Closer to the Body: During this movement, the arm continues moving backward at a gentle angle. The palms gradually move away from the thighs, extending away from the gluteus maximus muscle.
     4. Thumb Moving Towards the Buttocks: The arm continues moving backward until the arm is almost parallel to the plane of the gluteus maximus. At this point, the angle between the arm and the body is approximately 15-20 degrees, and the thumb points behind the buttocks.
     5. Additional Elbow Rotation: The forearm bends at the elbow by 90 degrees, causing the thumb to point upwards. This movement creates an additional angle between the arm and the forearm, with the arm moving backward and the forearm pointing upwards.

   • Maximum Range of Motion: At the maximum range of motion, the arm moves backward until the hand is nearly parallel to the body. This movement is still at a slight angle to ensure a natural range of motion for the arm. The thumb is behind the buttocks.

In the image I want to see the position of "Additional Elbow Rotation".