Article

The importance of assessing proprioceptive function for
rehabilitation after neurological or orthopedic injury has long been recognized.
Yet, neither the validity nor the accuracy of the available tests is firmly
established. Testing typically involves repeated matching of a given joint
position with the same or opposite limb where the difference between the 2
positions indicates proprioceptive acuity. The aim of this study was
to compare position sense acuity between ipsilateral and contralateral matching
methods against a psychophysical threshold method to establish the accuracy and
relationships between these models. DESIGN: A repeated-measures design was used.
METHOD: Assessment of forearm position sense for a 10-degree reference position
in 27 young adults who were healthy. RESULTS: Psychophysical thresholds were
revealed to be the most precise and least variable acuity measure. The mean
(+/-SD) threshold (1.05 degrees +/-0.47 degrees ) was significantly lower than
mean position errors obtained by both joint position matching tasks (ipsilateral:
1.51 degrees +/-0.64 degrees ; contralateral: 1.84 degrees +/-0.73 degrees )-a
44% to 75% difference in measurement accuracy. Individual participant position
errors correlated poorly with respective thresholds, indicating a lack of
concurrent validity. Position errors for both matching methods correlated only
mildly with each other. LIMITATIONS: The data represent performance of a healthy,
young adult cohort. Differences between methods will likely be more pronounced in
aging and clinical populations. CONCLUSIONS: Threshold testing and joint position
matching methods examine different physiological aspects of proprioceptive
function. Because threshold testing is based on passive motion, it most closely
reflects afferent sensory feedback processing (ie, proprioception). Matching
methods require active motion and are consequently influenced by additional
sensorimotor processes. Factors such as working memory and transmission between
brain hemispheres also influence joint matching task outcomes.

Langue : ANGLAIS