The authors have created the Step Trainer, a gait controlling device, in order to improve the gait patterns of patients with neurological disorders. The divice is composed of two parts, the light and the sound portions. The patient is instructed to place his foot on each edge of spot light that has a diameter of 10cm. The spot light is cotrolled by the angle adjustment device. The sound portion influences the gait by the use of rhythm. The effects were evaluated by measuring the foot marks and 8mm movie.
The effects of Step Trainer were as follows:
1. improved magnetic gait.
2. improved marche a petit pas.
3. shortened differences between uneven lengths of bilateral steps.
4. decreased drag walk.
5. widened scissors' gait and diminished wide base.
6. controlled walk cadence.
7. relaxed abnormal hypertonicity and spasticity.
8. decreased standard deviation of step length and stride width.
The decision whether the Step Trainer should be used or not must be made by a physician or a physiotherapist.

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Knee joint function of the aged were evaluated by the assessment of muscular activities and joint movements during several daily activities including the level walking, ascending and descending stairs, standing up from the chair and Japanese way of sitting.
Electromyography was taken from the each head of the quadriceps and inner hamstrings. The quantity of muscular activities was normalized by the activity in the maximum effort on resistive knee joint extension and flexion for each subject.
Electrogoniometer was attached to the knee axis and sometimes also to the hip joint. Foot switches were applied to both feet.
Sixteen healthy aged subjects (from 64 to 82 years of age) and 15 patients with knee joint disorders were evaluated during the same kind of activities.
The results were as follows:
1. No definite difference was noted in muscular activity pattern between men and women in the healthy group.
2. Considerable muscular activities of hamstrings were demonstrated during the ascending and descending stairs in most of the aged subjects.
3. The quantity of muscular activities of the patient with knee joint instability was remarkably higher than the healthy subjects even in level walking.
4. The representation of EMG activity of the patients during stance phase in ascending or descending stairs was also different from that of healthy aged subjects.
5. The activity of vastus lateralis was rather higher than that of vastus medialis in the patient who had varus deformity of the knee joint.
6. Early quadriceps muscular contraction was recorded before the heel contact in the patient with knee joint instability. This fact was found more prominently in descending stairs.
7. The evaluation of the knee joint activity was attempted also to the condition after reconstructive surgery and it was considered that some informations might be useful for future rehabilitation program.

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The first objective of this study was to investigate the EMG pattern of knee joint muscles, the inner hamstrings, vastus lateralis, vastus medialis, rectus femoris and vastus intermedius during some ADL movements. Those movements included level walking, ascending and descending stairs, rising from a chair, standing up from deep knee bending, standing up from Japanease way of sitting and stepping up on a stool (42cm in height).
The second objective was to find differences between the young and the aged in each movement. Sixteen aged persons ranging in age from 64 to 82 years and ten young persons from 22 to 35 years.
In this study, an electrogoniometer of the knee and foot switches were simultaneously used.
A rectifying and smoothing method was used to process EMG activities, and each of time scale and magnitude was normalized.
The processed signals of several movement cycles were averaged.
Results of this study were as follows:
(1) The quadriceps muscles showed the highest activity during standing up from Japanese way of sitting and stepping up on a stool.
(2) During level walking, quadriceps muscles showed slight EMG activity which was approximately 10% of maximum in the young and 20% in the aged.
(3) The EMG activity of the rectus femoris took the different patterns from the vastus lateralis and vastus medialis during ADL movements.
(4) The EMG activity level of the aged group was higher than that of the young group during almost all ADL movements, especially in the inner hamstrings.
(5) Duration of EMG activities were longer in the aged, onset and cessation time of EMG were earlier and later in the aged during ascending and descending stairs respectively.

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There have been a large number of investigations in connection with the Electromyogram (EMG) in movement analysis. There are also many papers as well as with the methodologies of EMG analysis. They, however, are concerned mostly with static movements.
Contrary to them, the movements which we have worked on are dynamic. The method for dynamic movement should be different from that for static one. Here we discuss ed the method to process the EMG with a particular emphasis on the dynamic movements. After such a processing, the EMG can be treated the same as other biomechanical signals such as angular displacement of joints, floor reaction force and so on. Therefore, we also discussed the procedure to process those biomechanical signals. And we present here a practical system for performing those procedures, specifically in knee joint movements.
The results and the discussions are as follows;
1) In our EMG measuring system, a rectifying and smoothing method was employed and other methods such as integration or pulse count methods were not, which allowed continuous waveforms of the processed EMG to be easily obtained.
2) The time constant of the smoothing circuit is approximately 33msec. This value is rather short compared with commonly used 100 to 200msec. Though the larger time constant raises no problem for static movements, it may cause an unacceptable delay for our dynamic ones. On the other hand, the shorter time constant may have trouble with ripples.
3) In order to get reliable recordings of the biomechanical signals from subjects, waveforms of ten or more movement cycles are averaged, after their time scales have been normalized and then they are converted into 256 data points by the linear interpolation method.
By the averaging procedure explained above, the resultant data may show the waveforms as if they were recorded from an average movement of the subject. In addition to that advantage, the resultant EMG may also show few ripples.
4) Our system is found to be useful and reliable by many experiments on young adults, aged people and patients with knee dysfunctions.

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[in Japanese]

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[in Japanese]

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