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The influence of lumbar disk herniations on gait
Abstracts
338
DEVELOPMENT OF A SUBJECT-SPECIFIC, DYNAMIC MODEL OF PATHOLOGICAL GAIT Gary T. Yamaguchi, Jonathan I. Green, and Daniel W. Moran Department of Chemical, Bio & Materials Engineering Arizona State University, Tempe, AZ 85287-6006 As part of a long-term study to determine the feasibility of predicting the postsurgical gaits of cerebral-palsied children via digital computer simulations, We developed a complex, 16 degree-of-freedom (DOF) walking model. This model is musculotendon-actuated, dynamic, in that it responds to the actions of forces and torques, and furthermore is bilaterally asynrmetric, so that the separate but dynamicallycoupled right and left legs can be configured with different dimensions, inertial properties, and musculotendon parameters. These features will allow us to match, inasmuch as possible with our model, the features specific to a particular individual. It is hoped that such "subject-specific models", in conjunction with pre- and post-surgical 3-D gait analysis, will enable us to correlate changes to the musculotendon actuators imposed during surgery with alterations in the gait patterns. This paper describes our progress to date, and focuses upon the development of the model and our initial efforts to use lower-extremity MRI scans to determine model scaling parameters.
QUANTIFYING INTERFACE PRESSURES IN BELOW-KNEE AMPUTEE SOCKETS MJ.N. Springer and J.R. Engsberg Department of Mechanical Engineering and Human Performance Laboratory The University of Calgary, Calgary, Alberta, TZN lN4, CANADA The purpose of this pilot study was to measure the pressures between the residual lib and the socket during walking using thin pressure sensors. One 30 year old male below-knee amputee (BKA) adult (Subject 1) and one 10 year old male BKA child (Subject 2) volunteered as subjects. Sensors (1 mm thin) were taped to four different residual limb lorations (anterior, posterior, medial, and lateral). Bony prominencesdetermined by a prothetist to be areas of low pressure and soft tissue locations determined to be areas of high pressure were marked on the sensors. The normal socket and prosthetic outer were then placed over the residual lib and sensors. Pressure data were collected with the subject walking along a short walkway. Two trials from each sensor were collected for the subjects. The results displayed a change in pressure throughout the support phase of the gait cycle for both the low and high pressureregions.Subject1 had hisgreatestpeakpressureon theposteriorwall (105kpa) whileSubject2 bad hisgreatestpeak pressure on the patellar ligament (120 kPa). The low pressure cycle for the lateral tibia1 condyle region peaked at the beginning of the cycle (10 kPa) for Subject 1, but peaked at the end of the cycle (24 kPa) for Subject 2. The different results between subjects could be due to subject age, socket age, anatomical characteristics of the residual limb, or the different characteristics of the prosthetists’ in fabricating the socket. Further investigations should consider establiimg acceptable pressure ranges by gathering data on many subjects and systematically altering the socket shape.
THE INFLUENCE
OF LUMBAR
O.D. Schipplein, G.B.J. of Orthopedic Surgery,
DIBK
that herniations.
BERNIATIONS
ON GAIT
Andersson, M. Hickey, Rush-Presbyterian-St.
could
aid
in
the
and
T.P.
preoperative
Andriacchi,
diagnoses
Department
of
disk
338
DEVELOPMENT OF A SUBJECT-SPECIFIC, DYNAMIC MODEL OF PATHOLOGICAL GAIT Gary T. Yamaguchi, Jonathan I. Green, and Daniel W. Moran Department of Chemical, Bio & Materials Engineering Arizona State University, Tempe, AZ 85287-6006 As part of a long-term study to determine the feasibility of predicting the postsurgical gaits of cerebral-palsied children via digital computer simulations, We developed a complex, 16 degree-of-freedom (DOF) walking model. This model is musculotendon-actuated, dynamic, in that it responds to the actions of forces and torques, and furthermore is bilaterally asynrmetric, so that the separate but dynamicallycoupled right and left legs can be configured with different dimensions, inertial properties, and musculotendon parameters. These features will allow us to match, inasmuch as possible with our model, the features specific to a particular individual. It is hoped that such "subject-specific models", in conjunction with pre- and post-surgical 3-D gait analysis, will enable us to correlate changes to the musculotendon actuators imposed during surgery with alterations in the gait patterns. This paper describes our progress to date, and focuses upon the development of the model and our initial efforts to use lower-extremity MRI scans to determine model scaling parameters.
QUANTIFYING INTERFACE PRESSURES IN BELOW-KNEE AMPUTEE SOCKETS MJ.N. Springer and J.R. Engsberg Department of Mechanical Engineering and Human Performance Laboratory The University of Calgary, Calgary, Alberta, TZN lN4, CANADA The purpose of this pilot study was to measure the pressures between the residual lib and the socket during walking using thin pressure sensors. One 30 year old male below-knee amputee (BKA) adult (Subject 1) and one 10 year old male BKA child (Subject 2) volunteered as subjects. Sensors (1 mm thin) were taped to four different residual limb lorations (anterior, posterior, medial, and lateral). Bony prominencesdetermined by a prothetist to be areas of low pressure and soft tissue locations determined to be areas of high pressure were marked on the sensors. The normal socket and prosthetic outer were then placed over the residual lib and sensors. Pressure data were collected with the subject walking along a short walkway. Two trials from each sensor were collected for the subjects. The results displayed a change in pressure throughout the support phase of the gait cycle for both the low and high pressureregions.Subject1 had hisgreatestpeakpressureon theposteriorwall (105kpa) whileSubject2 bad hisgreatestpeak pressure on the patellar ligament (120 kPa). The low pressure cycle for the lateral tibia1 condyle region peaked at the beginning of the cycle (10 kPa) for Subject 1, but peaked at the end of the cycle (24 kPa) for Subject 2. The different results between subjects could be due to subject age, socket age, anatomical characteristics of the residual limb, or the different characteristics of the prosthetists’ in fabricating the socket. Further investigations should consider establiimg acceptable pressure ranges by gathering data on many subjects and systematically altering the socket shape.
THE INFLUENCE
OF LUMBAR
O.D. Schipplein, G.B.J. of Orthopedic Surgery,
DIBK
that herniations.
BERNIATIONS
ON GAIT
Andersson, M. Hickey, Rush-Presbyterian-St.
could
aid
in
the
and
T.P.
preoperative
Andriacchi,
diagnoses
Department
of
disk