The Obstinate PIP Joint Philadelphia Hand Rehabilitation Meeting March, 2014 Judy C. Colditz. OT/L, CHT, FAOTA www.HandLab.com PIP JOINT MP joint extended o Oblique fibers have straighter line of pull to PIP joint MP joint flexed o Oblique fibers less effective o Role of oblique fibers influenced by position of MP joint EXTENSOR DIGITORUM COMMUNIS Pull proximal to MP: o MP extension/hyperextension o Slight PIP extension o Very slight DIP extension PIP joint extensor o Except when MP joint hyperextended o Also extends DIP joint Indirectly via conjoined lateral bands By extending PIP Contraction of EDC with PIP stiffness o Clawing of MP joint PIP JOINT EXTENSION Central Slip & Oblique fibers o Extend the PIP joint Lateral bands & Conjoined lateral bands (with EDC) o Extend the DIP joint WHAT EACH MUSCLE DOES PRIMARY SECONDARY With MP joint extended Interossei EDC Lumbrical With MP joint flexed Lumbrical EDC Lumbrical PIP JOINT EXTENSION SPLINTING o Active Redirection UNIQUE LITTLE FINGER o Problematic PIP Joint Extension Indirect EDC/EDM ©HandLab, 2014 1 One interosseous muscle Mobile CMC & MP joints MP Flexion/IP Extension o ADM o 3rd Volar Interosseous o Hypermobile CMC Joints Little MP joint Use of a Relative Motion Orthosis for Regaining PIP Joint Flexion or Extension The relative motion orthoses (also called Immediate Controlled Active Motion [ICAM] or the yoke orthosis) was developed to treat extensor tendon lacerations. When for active redirection, the goal is to control/limit MP joint motion. Below are suggestions. See what works best to balance of motion for your patient!!! References 1. Digital Dynamics: Understanding Intrinsic and Extrinsic Finger Control.[Video]. Raleigh, NC: HandLab, a division of RHRC, Inc., 2008. Available from www.handlab.com ©HandLab, 2014 2