What arm?
Yes Your Shadow Does Change When You Move,Because Let's Say You See Your Shadow And You Move Your Arm,Your Arm Blocks The Sun And The Place It Is Blocking The Sun From Takes The Shapes Of Whatever Is Blocking,It In This Case Your Arm,So It Looks Like Your Arm,Head,Legs...etc
Bones will not cause the arm to be in a straight position, instead, muscle and tendons will cause the arm to be straight.
The bones will heal in the wrong position therefore the elbow might not be able to bend and move. If this happens, the way some doctors reset the arm is by re-breaking the elbow then setting the arm in the correct position in surgery.
when you bend your arm
The arm is engaged in a motion called flexion when moving from position A to position B. This involves reducing the angle between the bones of the arm at a joint, such as the elbow or shoulder.
Move your arm in circles
The humerus bone is the one in your upper arm, and it is needed when you want to move your arm.
Which muscles? If all the muscle are clenched it will be perfectly still but that could be in any position depending on what position the arm was in ot start with.
Reset the wiper arm. At the bulkhead end of the arm is a big nut on a tapered shaft. (might be under a cover). Slacken the nut and loosen the arm from the tapered shaft. Move the wiper to a different position on the windshield and tighten the nut. Test wiper to see that blade returns to the new position.
To properly use the press arm on this exercise machine, adjust the seat height so your arms are at a 90-degree angle when gripping the handles. Push the handles forward while exhaling, then slowly return to the starting position while inhaling. Repeat for desired number of repetitions.
extention
With muscles!