S-3-05-01
A NEW SYSTEM FOR THREE-DIMENSIONAL GAIT RECORDING USING ELECTROMAGNETIC TRACKING
Kazushige Kobayashi, Kyozo Yonemoto (The Jikei University, Tokyo, Japan), Lennart Gransberg, Evert Knutsson (Karolinska Hospital, Stockholm, Sweden)
We developed a new system for three-dimensional gait recording. It was based upon an electromagnetic tracking instrument using sensors to record magnetic flux in magnetic fields alternatively generated by three orthogonal coils in a transmitter. The instrument records coordinates and angular orientations of the sensors in three planes. The transmitter was kept in a fixed position to allow recordings of absolute positions and orientations in a walkway. Relative angles were computed. After compensation to correct environmental influences, the errors of x, y and z coordinates were <2.0 cm, and the error of angle in the sagital, coronal and transverse planes <1.0 degree within an area sufficient for recording of the movement in a full stride. Records with 4 sensors fixed to the trunk and leg segments could be used to determine gait movements in three planes with similar, well defined precision in all dimensions.
S-3-05-02
STEP-DOWN-TEST. A NEW FUNCTIONAL GAIT-TEST FOR QUANTITATIVE REHABILITATION OUTCOME MEASUREMENT.
Th. L. Bochdansky, J. Kastner, M. Schmidt-Dumbacher, M. Knapp, P. Wagner, H. Kristen (Rehabilitation Center, AUVA, A-3400 Klosterneuburg, Austria)
Walking downstairs is a critical ability in activities of daily live after any operation on the knee. Therefore we designed a step-down-test with 2 Kistler force plates and compared these datas with a well known clinical score (Lysholm score). All parameters of ground reaction force measurements have been related to body weight. We used 2 parameters of the vertical forces for the correlation with the values of the Lysholm test. 1.) Load maximum of the initial phase (LM), 2.) rate of weight bearing (RW). For further calculation the individual differences between operated and nonoperated side were determined. 48 patients (male: 29, female: 19) took part in the first series. Tests were performed in the first and in the last week of a 6 to 8 week rehabilitation program (inpatient clinic).
The step-down-test turned out to be a quick test (5 minutes for 10 trials of normal walking and 10 trials of step down). It is easy to handle for patients and it is independend of any special person to manage the test. Therefore it is easy to standardise the setting. No correlation was found between this quantitative functional test and the subjective score (especially no correlation between pain and force parameters). Correlation of LM and RW improved during the rehabilitation (LM: from r=0.933 to r=0.959; RW: from r=0.895 to r=0.935).
We conclude that the step-down-test gives a new description of an important function in daily living and thus the rehabilitation progress can be assessed quantitatively.
