sentences:  The same is true for the furcula, a bone which enhances skeletal bracing for the stresses of flight.The mechanics of an avian's wings involve a complex interworking of forces, particularly at the shoulder where most of the wings' motions take place.These functions depend on a precise balance of forces from the muscles, ligaments, and articular cartilages as well as inertial, gravitational, and aerodynamic loads on the wing.