The effect of industrial back belts and breathing technique on trunk and pelvic coordination during a lifting task.
METHODS
Relative phase angle was used to study segmental motion patterns during a lifting and lowering task.


OBJECTIVE
To investigate the effect of back belts, breathing technique, and their interaction on lumbar and pelvic motion patterns.


BACKGROUND
Trunk and pelvic coordination has been investigated in healthy and low back pain populations. Back belts have been shown to alter range of motion and intra-abdominal pressure. Little has been reported about belts and coordination during lifting and lowering. Phase angle has been used for quantifying segmental coordination.


METHODS
Six individuals performed lifting/lowering tasks with a 23-kg load under elastic, rigid, and no belt conditions. During a second session, individuals were trained in Valsalva's maneuver and repeated the protocol. Cinematography was used to track trunk and pelvis displacements.


RESULTS
Segmental coordination during lowering generally was found to be the inverse of lifting. Significant differences in the relation between lumbar and pelvis phase angles were found during the initial stage of lifting because of the interaction of belt use and breathing. Lumbar range of motion decreased significantly with belt use during lifting and lowering. No significant change in pelvis range of motion was observed.


CONCLUSIONS
Back belt use and breathing technique interacted during the initial stage of lifting to significantly alter the lumbar and pelvis phase angles. The change in segmental kinematics was similar to that previously reported for patients with a history of low back pain. Lumbar range of motion significantly decreased with belt use during both lifting and lowering.
McGorry
R W
RW
Liberty Mutual Research Center for Safety and Health, Hopkinton, Massachusetts, USA. raymond.mcgorry@libertymutual.com
Hsiang
S M
SM
D000293:Adolescent; D000328:Adult; D001696:Biomechanical Phenomena; D006801:Humans; D017770:Lifting; D008161:Lumbosacral Region / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D010388:Pelvis / Q000502:physiology*; D011482:Protective Devices / Q000706:statistics & numerical data*; D016059:Range of Motion, Articular / Q000502:physiology; D012119:Respiration; D014636:Valsalva Maneuver / Q000502:physiology; D014741:Video Recording / Q000379:methods