The wings are the most important part of the flight apparatus of a bird and consist of feathers, bones, muscles, nerves, and patagial skin flaps. The complex kinematics of wing beats and the perfect control of aerodynamics make avian flight possible. An impaired flight can be viewed as an avian lameness; therefore, a better understanding of avian locomotion can help to diagnose and to evaluate the avian patient, especially when perfect flight is required for release of wild birds. Every condition affecting a specific part of the wing can lead to serious biomechanic and aerodynamic consequences during flight. This review summarizes wing mechanics that might be of clinical relevance for avian practitioners considering the current experimental and theoretical scientific knowledge available on avian flight in conjunction with observations of birds in various wildlife centers.