Middle and ring fingers are more exposed to pulley rupture than index and little during sport-climbing: a biomechanical explanation.
Clinical Biomechanics. 2008-06-01; 23(5): 562-570
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1. Clin Biomech (Bristol, Avon). 2008 Jun;23(5):562-70. doi:
10.1016/j.clinbiomech.2007.12.009. Epub 2008 Feb 11.
Middle and ring fingers are more exposed to pulley rupture than index and little
during sport-climbing: a biomechanical explanation.
Vigouroux L(1), Quaine F, Paclet F, Colloud F, Moutet F.
(1)Movement and Perception Laboratory, CNRS UMR 6152, University of the
Mediterranean, Faculte des Sciences du Sport, Case postale 910, 163, avenue de
Luminy, 13288 Marseille, France.
BACKGROUND: Finger pulley injury is a common incident observed during
sport-climbing. The total rupture of one or several pulleys is highly
debilitating and requires surgical reconstruction and/or rehabilitation programs.
Literature reports show that fingers are not equally exposed to this injury. The
ring and middle fingers are usually injured while the index and little fingers
are less exposed. The objective of this study was to determine the biomechanical
factors leading to the enhanced exposure of ring and middle finger pulleys.
METHOD: Eight subjects were required to exert maximal four-finger force in a
specific sport-climbing finger posture. External fingertip forces and finger
joint postures were used as input data of a specifically developed biomechanical
model of the four fingers (i.e., index, middle, ring and little). This model was
based on classical Newton static laws and used an optimization process to
quantify the flexor tendon tensions and the pulley forces in each finger. Passive
participation of ligaments was also considered into mechanical equations.
FINDINGS: Results showed that two main factors could explain the enhanced
exposure of ring and middle fingers. Firstly, the fingertip force intensities
applied by these two fingers were higher than those observed for the index and
little fingers. Secondly, results show that the pulley forces of the ring and
middle fingers were close to their rupture thresholds, while it was not the case
for the two other fingers. This could be explained by a specific localisation of
the finger pulleys of the ring and middle fingers leading to enhanced pulley
INTERPRETATION: These results are relevant and could help clinicians to
understand finger pulley pathologies and adapt the surgical interventions to
reconstruct the fingers pulleys.
PMID: 18267349 [Indexed for MEDLINE]