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00005768-200305001-0070900005768_2003_35_s129_imamura_biomechanics_5miscellaneous< 17_0_5_0 >Medicine & Science in Sports & Exercise©2003The American College of Sports MedicineVolume 35(5) Supplement 1May 2003p S129RADAR AS A MEANS TO MEASURE THE BIOMECHANICS OF GAIT: A VALIDITY STUDY[C-15O FREE COMMUNICATION/POSTER GAIT]Imamura, R T.1; Johnson, B F.1; Marshall, W S.11Georgia State University, Atlanta, GA, California State University, Sacramento, CAPURPOSEThe purpose of this study was to use the latest technology in video imaging techniques to help develop and validate the necessary software and mathematical theory to identify human walking parameters (stride length (SL)) using radar.METHODSTwo different instruments were used simultaneously to measure the gait of 20 apparently healthy college-aged male subjects: an experimental gait-measuring radar device (single-frequency, narrow-band (10.5 GHz), continuous-wave) and a high resolution motion capture real-time system with a six infrared video camera (60 Hz) array. The first 10 subjects were used to develop algorithms, based on amplitude measurements (decibels (dB)), necessary to predict radar data from video-based data, while the remaining 10 subjects were used to test the device.RESULTSThe forefoot region of the foot exhibited a dB value within a range −22.9201 to −26.3641 during the swing phase. Amplitude signal overlap of larger body parts over smaller body parts limited the identification of the forefoot within all gait phases but the swing phase. Macro programs were formulated to refine the radar forefoot data into frequency versus time curves and subsequently calculate position data. Interpolation and smoothing of curves were performed using curve estimations from a statistical software program. A dependent samples t-test indicated a significant difference (p = .000) between SL measurements from the radar and video-based devices. Radar SL values were statistically larger than those measured through the video-based device. Analysis through video-based analysis indicated a distinct possibility of the contra-lateral hand creating a signal overlap of the forefoot.CONCLUSIONSThe radar device cannot be recommended as a valid means to measure gross walking parameters at this stage in development. Suggestions for future research include removing signals created by the hand to improve frequency curve estimations of the forefoot and systematically identify other body parts to attain segment and center of mass information.RADAR AS A MEANS TO MEASURE THE BIOMECHANICS OF GAIT: A VALIDITY STUDYImamura, R T.; Johnson, B F.; Marshall, W S.C-15O Free Communication/Poster Gait535