This study investigated the reproducibility of test results of the Langer Electrodynogram (EDG) foot sensor system which quantifies discrete pressures and temporal episodes at the interface of the foot and appropriate surface. In phase one of the study, the effects of transducer placement errors were evaluated by manipulating sensors. In the single subject studied, results suggested that placement errors of a single transducer within ${ pm1}$ cm from its original location do not significantly affect the temporal components of gait, though errors as low as ${ pm0.5}$ cm from an initial position significantly affected pressures. / In phase two, ten healthy subjects performed 25 straight line barefoot walks on each of two separate days at an average natural cadence of 111.06 steps/min. with identical transducer placements on each day. Twenty-five gait variables were analysed for unilateral and asymmetries estimates. Analyses of variance revealed few significant differences among trials. Further, while there were no significant overall differences between days, there were significant subject-by-day interactions due to between-day differences in individual subjects, in part related to inherent subject-performance variability. Since clinicians are interested mainly in individual subject analyses rather than a mythical average subject, caution is advised in data interpretation when monitoring a subject on different days, even with as many as 25 trials per session and identical landmark placements. Pressures, while reliable within a single testing session, should not be used for inter-day comparisons and may not be appropriate for monitoring asymmetries because slight variations in placement will account for the measured differences between limbs.

Thesis (PhD)--University of South Australia, 1994

Thesis (PhD)--University of South Australia, 1994

Thesis (M.Sc.). / Written for the Dept. of Kinesiology and Physical Education. Title from title page of PDF (viewed 2008/05/28). Includes bibliographical references.

xiii, 143 p. : ill. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / This study evaluated the effects of two marker placement methods and two data analysis methods on running gait analysis. Markers placed on the shoe heel counter were compared with markers placed directly on the calcaneous and visible through heel windows cut into the shoe. When analyzed using a traditional group design no significant differences were found between marker conditions for rear foot eversion excursion, percent stance at which peak eversion occurred, maximal instantaneous eversion velocity, or maximal instantaneous vertical loading rate. Ankle frontal plane variability was significantly different between conditions. When analyzed with a single subject design some individuals demonstrated significant differences between conditions while others did not. In some individuals the heel windows condition revealed previously masked coupling parameters thought to be related to injury. The results of this study suggest the heel windows method and single subject analysis should be used for a longitudinal study of runners. / Committee in Charge: Dr. Li-Shan Chou, Chair; Dr. Louis Ostemig; Dr. Stanley James

No description available.

Gait analysers are devices or systems that quantify the planter /' pressures as they occur under the foot. The data obtained, be it. in visual or digital format, assists the medical practitioner in the diagnosis of an abnormality of gait. This thesis describes the development of a low-cost, portable, inshoe gait analysis device which overcomes all the limitations experienced by other systems currently in use. The non-availability of .robust, yet small pressure transducers, required the design and manufacture of these components. Capable of being embedded within an insole environment, it allows for the unobtrusive monitoring of localised planter pressures associated with all modes of gait. The transducer output, being analogy and continuous in nature, allows for the production of a real-time pressure display an important requirement for the therapeutic assessment and treatment of patients. The flexibility and accuracy of this system surpasses that of other systems. Its configuration provides for operation in remote environments, allowing for gait measurements under specific ambulation conditions. Use of a new transducer monitoring technique, in addition to a new video mixing technique, has enabled this device to compete with those systems making use of expensive processing and display equipment. Two prototype gait analysis systems have been built and extensively tested under clinical conditions. The results obtained provide unique, hitherto unavailable data, which can now be used for a more precise classification of gait disorders. It is already clear that the data will provide the basis for more accurate diagnosis and therefore more appropriate treatment of a variety of gait.

Currently normalcy indices have not been used to evaluate the gait of normal healthy adults. The purpose of this study was to assess the appropriateness of using a normalcy index in assessing gait patterns by investigating normalcy indices of different compositions created from an adult population. Thirty-seven normal and healthy subjects between the ages of nineteen and sixty-six underwent a clinical gait analysis. Ten trials from the left and right sides of the body were averaged. From the averaged data, sixteen kinematic variables were chosen for further analysis. Principal component analysis was applied to the variables and four separate normalcy indices were formed. They consisted of a right side, left side, left and right combined, and average of both sides indices. For the left side index, 23.41% of the variance was accounted for in the principle component. In the right side index, 25.35% of the variance was accounted for. 25.45% and 23.95% of the variance was accounted by the PC in the average of both sides and the left and right combined indices. The mean index scores of the left and right indices are 6.48 and 8.38. Index score for the average of both sides and left-right combined indices is 6.80. A paired samples t-test showed that the left and right indices were significantly different at the .01 level. The mean of the index from both sides and the left-right combined were not significantly different with an alpha of 0.969. The significant difference between the left and right side indices suggests that with further refinement, normalcy indices may possibly be used to assess the symmetry of gait. / School of Physical Education, Sport, and Exercise Science

Thesis (Ph.D.)--University of Delaware, 2009. / Principal faculty advisor: James G. Richards, College of Health Sciences. Includes bibliographical references.

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