Role of muscles in the stabilization of ligament-deficient wrists.
This article reviews the results of a series of cadaver investigations aimed at clarifying the role of muscles in the stabilization of ligament-deficient wrists. According to these studies, isometric contraction of some forearm muscles induces midcarpal (MC) supination (ie, the abductor pollicis longus, extensor carpi radialis longus, and flexor carpi ulnaris), whereas other muscles induce MC pronation (ie, the extensor carpi ulnaris). Because MC supination implies tightening of the volar scaphoid-distal row ligaments, the MC supination muscles are likely to prevent scaphoid collapse of wrists with scapholunate ligament insufficiency. MC pronator muscles, by contrast, would be beneficial in stabilizing wrists with ulnar-sided ligament deficiencies owing to their ability to tighten the triquetrum-distal row ligaments. Should these laboratory findings be validated by additional clinical research, proprioceptive reeducation of selected muscles could become an important tool for the treatment of dynamic carpal instabilities.
Hand Unit, Orthopaedics Department, Clínica Activamutua Tarragona, Tarragona, Spain; Wrist Biomechanics Study Group, Anatomy Department, University of Barcelona, Barcelona, Spain. Electronic address: mireiaesplugas@gmail.com.
Mireia
M
Esplugas
Wrist Biomechanics Study Group, Anatomy Department, University of Barcelona, Barcelona, Spain; Institut Kaplan, Passeig de la Bonanova, Barcelona, Spain.
Marc
M
Garcia-Elias
Wrist Biomechanics Study Group, Anatomy Department, University of Barcelona, Barcelona, Spain; Institut Kaplan, Passeig de la Bonanova, Barcelona, Spain; Hand Unit, Orthopedics Department, Hospital Universitari Vall d'Hebrón, Universitat Autònoma de Barcelona, Barcelona, Spain.
Alex
A
Lluch
Wrist Biomechanics Study Group, Anatomy Department, University of Barcelona, Barcelona, Spain.
Manuel
M
Llusá Pérez
D001696:Biomechanical Phenomena; D002102:Cadaver; D050824:Carpal Joints / Q000033:anatomy & histology / Q000502:physiology*; D004210:Dissection; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D007593:Joint Instability / Q000503:physiopathology* / Q000517:prevention & control; D008023:Ligaments, Articular / Q000033:anatomy & histology / Q000503:physiopathology*; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000502:physiology*; D011403:Pronation / Q000502:physiology; D016059:Range of Motion, Articular; D012380:Role; D013484:Supination / Q000502:physiology; D014955:Wrist Joint / Q000033:anatomy & histology / Q000502:physiology*
Lunotriquetral instability; Midcarpal instability; Muscular control; Scapholunate instability; Wrist stability