ExRx.net > Kinesiology > Articulations > Joint
Bending the joint resulting in a decrease of angle; bringing forearm toward upper arm.
Straightening the joint resulting in an increase of angle; bringing forearm away from upper arm.
Also see Forearm. Mentioned articulations occur during concentric phase of exercise video examples.
Low-Volume, Progressive-Intensity Weight Training
Toning with Weights
Progressive Full Body Calisthenic Workout