Effect of simulated rock climbing finger postures on force sharing among the fingers.
OBJECTIVE
To study the forces applied by each finger in different joint postures simulating rock climbing gripping postures.


METHODS
Subjects in sitting posture applied fingertip forces perpendicular to horizontal force sensors in three different finger postures.


BACKGROUND
Data provided by the literature indicate that middle and ring finger are commonly injured. However, no quantitative assessment of the forces applied by each finger related to the joint postures has been made.


METHODS
Six elite rock climbers performed finger flexion in a single-finger task and a four-finger task. The tests were conducted in an extended posture, a curved posture (the joints belonging to the finger were flexed) and an intermediate posture (the joints were flexed, except the distal one which was fully extended). Each fingertip force was expressed in absolute value and in percentage of the maximal force capacity of the finger.


RESULTS
The greater force was applied by the middle finger (20.8 N), whatever the posture. The relative involvement amounted to 105% for the ring finger in the curved posture.


CONCLUSIONS
The great force applied by the middle finger and the great relative involvement of the ring finger in the curved posture seem to be the main factors of injuries of these fingers.


CONCLUSIONS
The analysis of force sharing among the fingers during different joint postures mimicking rock climbing is essential to a better understanding of finger injuries.
Quaine
Franck
F
EA 597, UFR APS, Université, Joseph Fourier, 1741 rue de la Piscine, BP 53 x, 38041 Grenoble cedex 9, France. franck.quaine@ujf-grenoble.fr
Vigouroux
Laurent
L
Martin
Luc
L
D000328:Adult; D001696:Biomechanical Phenomena; D005385:Fingers / Q000502:physiology*; D006801:Humans; D008297:Male; D013177:Sports / Q000502:physiology*