Article

There is increasing evidence that individuals with non-specific low back pain
(LBP) have altered movement coordination. However, the relationship of this
neuromotor impairment to recurrent pain episodes is unknown. To assess
coordination while minimizing the confounding influences of pain we characterized
automatic postural responses to multi-directional support surface translations in
individuals with a history of LBP who were not in an active episode of their
pain. Twenty subjects with and 21 subjects without non-specific LBP stood on a
platform that was translated unexpectedly in 12 directions. Net joint torques of
the ankles, knees, hips, and trunk in the frontal and sagittal planes as well as
surface electromyographs of 12 lower leg and trunk muscles were compared across
perturbation directions to determine if individuals with LBP responded using a
trunk stiffening strategy. Individuals with LBP demonstrated reduced peak trunk
torques, and enhanced activation of the trunk and ankle muscle responses
following perturbations. These results suggest that individuals with LBP use a
strategy of trunk stiffening achieved through co-activation of trunk musculature,
aided by enhanced distal responses, to respond to unexpected support surface
perturbations. Notably, these neuromotor alterations persisted between active
pain periods and could represent either movement patterns that have developed in
response to pain or could reflect underlying impairments that may contribute to
recurrent episodes of LBP.
CI - Copyright (c) 2011 Elsevier Ltd. All rights reserved.

Langue : ANGLAIS