Skip directly to search Skip directly to A to Z list Skip directly to page options Skip directly to site content

NIOSHTIC-2 Publications Search

Search Results

Disturbed paraspinal reflex following prolonged flexion-relaxation and recovery.

Authors
Rogers-EL; Granata-KP
Source
Spine 2006 Apr; 31(7):839-845
NIOSHTIC No.
20030730
Abstract
Repeated measures experimental study of the effect of flexion-relaxation, recovery, and gender on paraspinal reflex dynamics. To determine the effect of prolonged flexion-relaxation and recovery time on reflex behavior in human subjects. Prolonged spinal flexion has been shown to disturb the paraspinal reflex activity in both animals and human beings. Laxity in passive tissues of the spine from flexion strain may contribute to desensitization of mechanoreceptors. Animal studies indicate that recovery of reflexes may take up to several hours. Little is known about human paraspinal reflex behavior following flexion tasks or the recovery of reflex behavior following the flexion tasks. A total of 25 subjects performed static flexion-relaxation tasks. Paraspinal muscle reflexes were recorded before and immediately after flexion-relaxation and after a recovery period. Reflexes were quantified from systems identification analyses of electromyographic response in relation to pseudorandom force disturbances applied to the trunk. Trunk angle measured during flexion-relaxation postures was significantly higher following static flexion-relaxation tasks (P < 0.001), indicating creep deformation of passive supporting structures in the trunk. Reflex response was diminished following flexion-relaxation (P < 0.029) and failed to recover to baseline levels during 16 minutes of recovery. Reduced reflex may indicate that the spine is less stable following prolonged flexion-relaxation and, therefore, susceptible to injury. The absence of recovery in reflex after a substantial time indicates that increased low back pain risk from flexion-relaxation may persist after the end of the flexion task.
Keywords
Muscles; Muscle-contraction; Muscle-tension; Physiology; Spinal-cord; Spinal-cord-disorders; Posture; Musculoskeletal-system; Muscle-physiology
CODEN
SPINDD
Publication Date
20060401
Document Type
Journal Article
Funding Type
Grant
Fiscal Year
2006
NTIS Accession No.
NTIS Price
Identifying No.
Grant-Number-R01-OH-007352
Issue of Publication
7
ISSN
0362-2436
Priority Area
Disease and Injury: Musculoskeletal Disorders of the Upper Extremities
Source Name
Spine
State
VA
Performing Organization
Virginia Polytechnic Institute and State University
TOP