You are correct. Brace height is the measurement from the sting to the deepest part od the grip (usually the top). A lower brace height bow has a shorter distance from the grip to the string when at rest which places it farther down your forearm toward your wrist. What usually happens as has been mentioned here, is that someone tries to shoot a draw length that is too long for them which forces their elbow to "lock" or they torque the bow at release and their forearm gets hit by the string as it comes forward.