Stretch it gently and hold the position, repeat as often as needed.
It's probably just fatigued
jumping off a 5 foot step i tried to stop myself by grabing a bar and it pulled my arm very hard and have had pain ever since
There is not a single muscle that rotates the upper arm. The name of the muscle that contributes in rotation of the upper arm is deltoid muscle.
they just do
Skeletal muscle is associated with the upper arm.
The brachialis is a muscle in the upper arm that flexes the elbow joint.
What are the tendon in your arm?
no
I believe when your lips are "jumping", that you're just having a muscle spasm.
It depends. But, the triceps are 2/3 of your upper arm.
Biceps or triceps
where you bored when you posted this question or have you pop you muscle in you left arm