It acts to flex the shoulder and rotate the arm laterally. It acts to flex the shoulder and rotate the arm medially. It acts to flex the elbow and extend the shoulder. The most common is the shaft flex. It acts to flex the tarsus and rotate the paw medially. The frame may flex with load, especially twisting on bumps. It acts to flex the hip and extend the stifle. When walking the toes could flex upwards to lift the membrane from the ground. Steel's exact flex and strength vary dramatically with heat treating. Its function is to advance the limb and flex the neck laterally. It acts to flex the tarsus and rotates the paw laterally. This finger was permanently deformed and unable to flex. Each finger may flex and extend, abduct and adduct, and so also circumduct. It acts to flex the stifle and extend the tarsus. It acts to flex the digits and extend the tarsus.