Arm Model

bone muscle tendon pulling force injury

In a healthy arm, muscle contraction pulls through the tendon on the forearm bone, rotating it around the elbow joint.

Test Movement

Muscle contraction 50%

Condition

Injury severity 50%

Muscle force 50%

Movement produced 50%

Elbow change 180°

Condition	Effect
Healthy	Force transfers efficiently from muscle to bone.
Muscle strain	Muscle can contract, but produces less effective force.
Tendon injury	Muscle force is not transferred efficiently to bone.
Upper arm fracture	The break creates an abnormal moving point in the humerus, so force can bend the arm at the fracture instead of producing normal movement only at the elbow.

Teaching model only. Real movement depends on multiple muscles, nerves, joints, pain, swelling, and injury severity.