title: Role of the extensor carpi ulnaris in the stabilization of the lunotriquetral joint. An experimental study.
abstract: METHODS
  Experimental laboratory-based research in biomechanics.
  
  
  BACKGROUND
  The mechanisms by which some lunotriquetral (LTq) ligament disruptions remain stable are not known.
  
  
  OBJECTIVE
  To investigate the contribution of muscles in preventing carpal destabilization when the LTq ligaments are torn.
  
  
  METHODS
  Ten fresh cadaver wrists, set vertical in a jig, were isometrically loaded through five wrist motor tendons. Changes in carpal alignment secondary to the application of loads were monitored by a Fastrak™ electromagnetic motion tracking device, before and after sectioning the LTq ligaments.
  
  
  RESULTS
  After LTq ligaments sectioning, wrist loading forced the triquetrum into flexion (5.4° average) and supination (2.9 ). The only muscle capable of extending and pronating the collapsed triquetrum was the extensor carpi ulnaris (ECU).
  
  
  CONCLUSIONS
  Inadequate ECU muscle function is an important destabilizing factor in LTq deficient wrists. Dynamic LTq instabilities may benefit from proprioceptionally training the ECU muscle, while avoiding carpal supination torques.
authors.affiliation: (a)Department of Orthopaedics, Hospital Ca'n Misses, Eivissa, Spain.
authors.forename: María Mayte
authors.initials: MM
authors.lastname: León-Lopez
authors.forename: Guillem
authors.initials: G
authors.lastname: Salvà-Coll
authors.forename: Marc
authors.initials: M
authors.lastname: Garcia-Elias
authors.forename: Alex
authors.initials: A
authors.lastname: Lluch-Bergadà
authors.forename: Manuel
authors.initials: M
authors.lastname: Llusá-Pérez
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D006801:Humans; D007593:Joint Instability / Q000503:physiopathology*; D008023:Ligaments, Articular / Q000293:injuries*; D018482:Muscle, Skeletal / Q000503:physiopathology*; D011434:Proprioception / Q000502:physiology; D014955:Wrist Joint / Q000503:physiopathology*
keywords: Carpal kinetics; Extensor carpi ulnaris; Lunotriquetral joint; Muscle control; Wrist instability