Journal article

Circumferential force production of the thumb

Li Z, Harkness D ...see all

Medical Engineering and Physics, vol. 26, issue 8 (2004) pp. 663-670

  • 9


    Mendeley users who have this article in their library.
  • 8


    Citations of this article.
Sign in to save reference


We developed an apparatus to measure maximal continuous circumferential forces of a digit in the transverse plane that is perpendicular to the longitudinal axis. Subjects with asymptomatic hands were asked to produce maximal forces in all directions at the proximal phalanx of the thumb. The force components during circumferential trials were used to construct a force envelope for each subject. The force envelope enlarged as the number of trials increased, and converged to a stable pattern after several trials. The shape of the force envelope was asymmetric and oblique, skewed towards the flexion/adduction direction. Maximal force (112.1??14.8 N) was generated in the direction combining flexion and adduction. The lowest force produced was only 50.3% of the maximal force in a direction combining extension and abduction. The forces in the direction of adduction, extension, abduction, and flexion were 60.1%. 61.9%, 51.5%, and 92.9% of the maximal force, respectively. The forces generated by circumferential exertions were comparable to the forces by focused directional exertions except in the flexion direction. Our methods have the potential to identify deviations from the normative force output pattern and help detect underlying impairments resulting from neuromuscular disorders. ?? 2004 Published by Elsevier Ltd on behalf of IPEM.

Author-supplied keywords

  • Envelope
  • Force
  • Hand
  • Thumb

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Get full text


  • Zong Ming Li

  • Daniel A. Harkness

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free