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The Influence of Abductor Function on Hip Reaction
Forces and Cartilage Degradation
Supervisors:
Dr Todd Stewart, iMBE, Mechanical Engineering, Leeds)
Co-Supervisor:
Prof John Fisher (iMBE, Mech Eng, Leeds)
Prof Zhongmin Jin (iMBE, Mech Eng, Leeds)
Dr Neil Messenger, Inst of Membrane & Systems Biology, Biol Sciences
Prof Anthony Redmond, Dept of Musculoskeletal Disease, LIMM
Mr Martin Stone, Leeds General Infirmary/Chapel Allerton Hospital
Abductor function is critical to facilitate normal gait to allow a smooth progression form toeoff to heel-strike. The abductors lift the leg laterally and assist in knee flexion so that the leg
does not contact with the ground when swinging forwards. When the abductors are not
functioning properly the person commonly tilts their pelvis to achieve the same goal,
however, this results in limping, an unnecessary lifting of the centre of mass and inefficiency
in the gait cycle. We postulate that the tilting of the pelvis also shifts the contact centre of
the hip and may result in adverse contact stresses that may lead to cartilage damage and
arthritis later on in life and the eventual need for a joint replacement. The damage would
occur on the muscle damaged side and on the contrallateral side (opposite hip/knee).
The purpose of the study is to produce a 3D model of gait concentrating specifically on the
role of the abductor muscles. The student will use a software package called Opensim,
utilizing patient gait analysis data from Chapel Allerton Hospital Leeds for the analysis of
joint reaction forces (magnitudes and directions). The student will also use the package to
investigate the influence of how the abductor muscles are modelled on the resulting reaction
forces at the hip. The modelling of muscles will be assisted by collaborations within IMBE
from a current international grant titled “Muscle UP”.
The project is supervised by a group of staff skilled in biomechanics (Stewart), inverse
dynamics (Messenger), and clinical gait analysis (Redmond) and will get additional support
from computational studies within the IMBE group (Jin) using Adams modelling. The student
may progress their studies towards an Adams model of the hip advancing previous work in
this area in hip mechanics. Patient data is readily available from collaborations with the
LMBRU (Leeds Musculoskeletal Biomedical Reserarch Unit) including staff in the areas of
imaging, surgery, and musculoskeletal mechanics, hence there is a wealth of support and
validation data for the study. The LMBRU group is currently studying Leg length
discrepancy with many of these patients suffering from abductor dysfunction.
The project involves conducting research in both clinical and engineering settings and is in
this way both demanding and exciting. The student will learn a wide range of skills in gait
analysis and engineering computational modelling in a University Engineering setting. The
student will join the IMBE (Institute of Medical and Biological Engineering ) research team
and thus be exposed to a wide range of cutting edge research in tissue engineering, spinal
biomechanics, cartilage regeneration, and joint replacement within a world renowned
research institute. Facilities within the IMBE have recently been upgraded making the IMBE
group’s facilities state of the art and boasting the largest independent joint replacement
testing facilities in the world.
The project outcomes will support tissue engineering studies that require accurate clinical
data for modelling cartilage substitution therapies to delay the need for invasive surgery and
hip replacement thus improving patient quality of life in the 50 years after 50.