title: The effect of individual isometric muscle loading on the alignment of the base of the thumb metacarpal: a cadaveric study.
abstract: Stability of the thumb carpometacarpal joint relies upon equilibrium between its ligaments, muscular support and joint congruity. We wanted to identify the muscles important in preventing or increasing dorsoradial subluxation of this joint. In ten cadaveric hands, a Fastrak® motion tracking device was used to assess the effects of individual isometric muscle loading on the base of the thumb metacarpal relative to the radius and to the base of the middle finger metacarpal. We found that the first dorsal interosseous muscle caused the least dorsoradial translation and highest distal migration of the base of the first metacarpal, whereas abductor pollicis longus was the primary destabilizer, increasing dorsoradial misalignment. The findings show different impacts of these muscles on joint alignment and stability, which suggests that treatment should be targeted to enhance the action of the primary stabilizing muscle, the first dorsal interosseous muscle.
authors.affiliation: Karolinska Institutet Södersjukhuset, Institutionen för klinisk forskning och utbildning, Stockholm, Sweden Department of Hand and Plastic Surgery, Stavanger University Hospital, Stavanger, Norway nathalie.mobargha@ki.se.
authors.forename: N
authors.initials: N
authors.lastname: Mobargha
authors.affiliation: Clinica Activamutua, Tarragona, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Esplugas
authors.affiliation: Department of Anatomy, Facultat de Medicina, Universitat de Barcelona, Barcelona, Spain Institut Kaplan, Barcelona, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Garcia-Elias
authors.affiliation: Department of Anatomy, Facultat de Medicina, Universitat de Barcelona, Barcelona, Spain Institut Kaplan, Barcelona, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Lluch
authors.affiliation: Clinic for Plastic Surgery and Hand Surgery, Technical University of Munich, Munich, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Megerle
authors.affiliation: Karolinska Institutet Södersjukhuset, Institutionen för klinisk forskning och utbildning, Stockholm, Sweden Hand & Foot Surgery Center, Stockholm, Sweden.
authors.forename: E
authors.initials: E
authors.lastname: Hagert
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena / Q000502:physiology; D002102:Cadaver; D052737:Carpometacarpal Joints / Q000502:physiology*; D005260:Female; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D004204:Joint Dislocations / Q000503:physiopathology*; D008297:Male; D050279:Metacarpal Bones / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D013933:Thumb / Q000502:physiology
keywords: Thumb carpometacarpal joint; joint stability; muscles; neuromuscular balance; osteoarthritis