Lumbo-Pelvic Loading During Lifting: Instrumentation and Modelling
Author(s)
Chung, Clarice Ka-Yee
Type
Thesis
Abstract
Low back pain is a common problem, which has been linked to repetitive lifting and high
loading. Previous studies investigating the relationship between lifting and spinal loads
have failed to consider the separate elements of the back. This study aims to compare
different lifting techniques (weightlifting and manual handling) using a multi-segmental
model of the spine.
The loading and movement characteristics of the lumbo-pelvic joint during sagitally
symmetric lifting were investigated. Kinematic and kinetic data were acquired with the
‘Flock of Birds’ electromagnetic sensors and a custom-built forceplate. Weighted boxes
and Olympic barbells were used to simulate occupational lifting and athletic weightlifting
respectively.
The results indicate a shift to back-driven lifting and a reliance on the momentum
of the upper body to move heavier weights. Over-extension of lumbar spine and pelvis
during the heavy lifts implies the increased role of the hip and back extensors in force
production. Moment did not increase significantly with load suggesting a physiological
limit to the moment that can be generated by the muscles; other factors must affect lifting
ability once this maximum has been reached.
A simultaneous study investigated the potential of the ‘balance board’ method for
measuring pelvic segment mass. Despite previous studies reporting the ease and accuracy
of this method for measuring segmental mass, the results were not deemed to be sufficiently
accurate for use.
This is the first study that attempts to compare lifting technique between subjects
with differing types and levels of training. Some training effects were seen to transfer between
tasks. These findings would imply that a compromise might be reached, combining
the advantages of manual handling and competitive lifting, which could result in a safer
and more effective lifting technique. From a clinical perspective, this may be helpful in
both treating patients and reducing healthcare costs.
loading. Previous studies investigating the relationship between lifting and spinal loads
have failed to consider the separate elements of the back. This study aims to compare
different lifting techniques (weightlifting and manual handling) using a multi-segmental
model of the spine.
The loading and movement characteristics of the lumbo-pelvic joint during sagitally
symmetric lifting were investigated. Kinematic and kinetic data were acquired with the
‘Flock of Birds’ electromagnetic sensors and a custom-built forceplate. Weighted boxes
and Olympic barbells were used to simulate occupational lifting and athletic weightlifting
respectively.
The results indicate a shift to back-driven lifting and a reliance on the momentum
of the upper body to move heavier weights. Over-extension of lumbar spine and pelvis
during the heavy lifts implies the increased role of the hip and back extensors in force
production. Moment did not increase significantly with load suggesting a physiological
limit to the moment that can be generated by the muscles; other factors must affect lifting
ability once this maximum has been reached.
A simultaneous study investigated the potential of the ‘balance board’ method for
measuring pelvic segment mass. Despite previous studies reporting the ease and accuracy
of this method for measuring segmental mass, the results were not deemed to be sufficiently
accurate for use.
This is the first study that attempts to compare lifting technique between subjects
with differing types and levels of training. Some training effects were seen to transfer between
tasks. These findings would imply that a compromise might be reached, combining
the advantages of manual handling and competitive lifting, which could result in a safer
and more effective lifting technique. From a clinical perspective, this may be helpful in
both treating patients and reducing healthcare costs.
Date Issued
2008
Date Awarded
2009-03
Copyright Statement
Attribution NoDerivatives 4.0 International Licence (CC BY-ND)
Advisor
Bull, Anthony
McGregor, Alison
Creator
Chung, Clarice Ka-Yee
Publisher Department
Bioengineering and Division of Surgery, Oncology, Reproductive Biology and Anaesthetics
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)