<prompt> Swan neck deformity -Flexion at PIP and DIP jointExtention at PIP and DIP jointFlexion at PIP and Extention at DIP jointExtention at PIP and Flexion at DIP joint  <response>: Ans. is d i.e., Extention at PIP and Flexion at DIP joint Boutonniere deformity: Flexion contracture of PIP joint and extension of DIP joint. Swan neck deformity: Hyperextension of PIP joint and flexion at DIP joint. 