Publication Date


Document Type


First Advisor

Zinger, Donald S.

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Electrical Engineering


Gait disorders; Knee--Wounds and injuries; Goniometry; Inclinometer; Feedback control systems


The purpose of this gait analysis study was to further research the electrogoniometric vibrotactile feedback methods that aid in patient gait therapy. As compared to the standard electrogoniometer used in patient therapy, a lighter, more comfortable device was designed and analyzed to provide the patient with specific information about his/her gait cycle during stance phase. Sensors were attached onto the patient's leg to acquire the necessary information. In this study, micro-arc electrolytic tilt sensors, or clinometers, were employed. Clinometers measure the angle, with respect to gravity, that provides linear information about the patient's knee joint angle. A time and frequency domain analysis was performed to reveal certain characteristics about the sensor's responses. The information concluded that, because of differing step and stride length and speed at which a person walks, only the time domain was of particular interest in determining the patients' problems such as hyperextension (HE). Research was done in two distinct phases, both preceded by baseline studies at Northern Illinois University (NIU). Phase I included five cognizant participating stroke patients at Marionjoy Rehabilitation Hospital (MJR). These patients were simply used for data collection purposes to first characterize the sensor's response. The setup included two sensors fastened onto the thigh and calf. The sensors were connected to a signal conditioning board, which was, in turn, connected to a "virtual instrument" driven data acquisition (DA) system. This DA system was interfaced to a computer which sat on a portable rolling cart. Patients were prepared and asked to walk 15 m in a straight line for a total of three trials to obtain an average. As a result of the Phase I initial data collection and analysis process, a vibratory device was developed. Phase II included three additional patients who were examined using the vibratory device. "Real-time" feedback was provided to the patient as he/she hyperextended during his/her therapy. These patients' trials were captured on video with the device in use. As a result, the first two patients were used as Phase II pilot studies to resolve any problems the device might have during the patient's therapy. The third patient in Phase II was used to evaluate the device daily in conjunction with a two-week therapy session. Both the patient and MJR found this study to be a useful predecessor to a modified device which indicates HE appropriately.


Includes bibliographical references (pages [74]-75)


x, 106 pages




Northern Illinois University

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