This disclosure relates to antagonistic dual receptor antigen-binding proteins, e.g. antibodies and methods of using the dual receptor antibodies for treatments of pathological diseases. The dual receptor antibodies may comprise an antibody to ActRII receptors and may be used to treat pathological condition. The pathological conditions can comprise muscle wasting diseases or any disease that requires stimulation of muscle growth.LA INVENCIÓN PROPORCIONA PROTEINAS FIJADORAS DE ANTIGENO ANTAGONISTAS DEL RECEPTOR DE ACCION DUAL Y SUS USOS