The mend of the bend-flexor pollicis longus tendon has an additional pulley distal to its point of angulation.
The tendon of flexor pollicis longus angulates at the trapezio-metacarpal joint level. The degree of angulation varies with extent of radial/ulnar deviation (Rack and Ross [1984] J. Physiol. 351:99-110). We report a fibrous pulley at this level that helps stabilize the tendon and facilitates its action. The morphology of the pulley is described. We believe that it has an important role to play in the unique function of the tendon facilitating the movement of the thumb perpendicular to the plane of the thumbnail.
Department of Anatomy, Medical School, University of Birmingham, Birmingham, United Kingdom.
Kuen Foo
KF
Chin
Mohamed
M
Khalid
Nitish
N
Gogi
Jonathan
J
Fussey
Donal
D
Shanahan
Subodh
S
Deshmukh
D001696:Biomechanical Phenomena; D004210:Dissection; D050823:Hand Joints / Q000033:anatomy & histology / Q000502:physiology; D006801:Humans; D050279:Metacarpal Bones / Q000033:anatomy & histology*; D008662:Metacarpophalangeal Joint / Q000033:anatomy & histology*; D013710:Tendons / Q000033:anatomy & histology* / Q000502:physiology; D013933:Thumb / Q000033:anatomy & histology / Q000502:physiology; D051222:Trapezium Bone / Q000033:anatomy & histology*