Twenty-one stroke patients (11 subjectively dysphagic, 10 not dysphagic) and 21 healthy men were examined by electroglottography (EGG) to determine the quantitative nature of their deglutition function. Impedance changes in cervical tissue were recorded with an EGG during deglutition. Three healthy men were examined by videofluorography simultaneously with EGG to determine the relationship between the two examinations.
The latency of EGG in the subjectively dysphagic patients was delayed significantly compared with the nondysphagics and healthy men (p<0.05, p<0.01). The magnitude of impedance change did not differ between the three groups. The duration and number of phase in EGG wave form in healthy subjects were shorter and significantly less compared with the subjectively dysphagic patients and nondysphagics (p<0.01, p<0.05). The results of videofluorography revealed that the EGG wave form was recorded when the larynx descended and the pharynx was dilatated.
These findings suggest that quantitative evaluation of deglutition function in stroke patients is possible by EGG examination and EGG has the potential to be used as a therapeutic modality in biofeedback.

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The floor reaction force and the joint displacement of a lower extremity were measured by conventional gait analysis technique. The weight and center of the gravity of the leg segments were measured by 2 directional image analysis. The data were fed to U-1200 small-computer to calculate the hip, knee, and ankle torque by the link model method. The surface EMG of the gluteus maximus, rectus femoris, medial hamstrings, and gastrocnemius were recorded during torque measurements.
A 40 year-old, healthy male performed sitting-down and standing-up motion to and from different heights. The torque and hip-heights relationships during consecutive and ten-days apart measurements showed good reproducibility, with some flactuation of the torque. The variation of the trunk inclination during each motion appeared to be responsible for the torque value flacutuation.
By observing standing-up and sitting-down from different heights, the hip extension torque became bigger when the hip lowered. The knee extension torque reached its maximum just after the buttock took off the chair, then the knee torque curves followed an identical trace. These results fit well to the clinical impression, and implied the validity of this method.
The surface EMG of the rectus femoris coincided well with the knee extension torque generation. The medial hamstrings, which are usually regarded as the knee flexor, showed vigorous EMG activities simultaneously with the knee extension and hip extension torque generation. Because of this evidence, the torque measured by this method cannot be regarded entirely as the muscle contraction force of the main movers.
The torque measurement by the link model method will be used widely in the field of rehabilitation. However, the weakness lies on the fact that there is no appropriate way to caliblate this method. The validity study of various kinds must be conducted hereafter.

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It is said that as to long latency somatosensory evoked potentials, especially those later than 100 msec of latency time, the potential reproducibility is not good for the clinical uses. In order to obtain reproducible potentials. we applied infrequent painful electric stimuli alternatively to the right and left index fingers with randomly variable interstimulus interval. Sixteen records were averaged from the scalp with the reference to both ears after the EMG artifacts were eliminated. We demonstrated that the first 16 records were free from potential reduction due to habituation effects.
Triphasic potentials of N1, P1, and N2 were obtained widely over the scalp without significant laterality between 100 and 500 msec of latency. Average latencies of N1, P1, and N2 in the age-matched control group were 150, 250, and 425 msec, respectively. Amplitudes of N1-P1 and P1-N2 were not different in the responses between the right and left stimulation. In the 73 cerebrovascular patients with unilateral supratentorial lesion, abnormality could be defined as reduction of N1-P1 amplitude in response to stimulation of the hemiparetic side. Such reduction was significantly correlated with disturbance of position or superficial sensation, but not with the degree of hemiparesis. Disturbance of the superficial sensation often coexisted with that of the position sense. However, significant correlation was also found between the potential reduction and the superficial sensory deficit in the patients with intact position sense.

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We studied the effects of electrical low-frequency stimulation (ELFS) on the energy metabolism of rat hindlimb muscles by Phosphorus-31 Magnetic Resonance Spectroscopy (³¹P-MRS). Energy metabolism was evaluated by the Phosphocreatine (PCr)/{Inorganic Phosphate (Pi)+Sugar Phosphate (SP)} ratio, PCr/(Pi+SP), and the intracellular pH was estimated from the chemical shift of Pi. ELFS enables skeletal muscles to produce both twitch and tetanus contractions. Twitch contraction exercise (TWE) was induced at 4Hz, and tetanus contraction exercise (TEE) at 67Hz. Stimulation voltage was 4V to produce both TWE and TEE.
The initial tension of TWE was 231.8±18.7 dynes, and that of TEE was 383.8±35.8 dynes. Later, tension of both TWE and TEE decreased with time.
The PCr/(Pi+SP) ratio in TWE was 1.2±0.1 and that in TEE was 0.6±0.1 in 2min of exercise. From 2min to the end of exercise, the ratio of both TWE and TEE returned with time. During exercise, the ratio of TWE maintained a lower value of the ratio than that of TEE. In 2min of recovery, the ratio of TWE was 3.6±0.1, and that of TEE was 2.9±0.2.
The intracellular pH of TWE was 6.84±0.03, and that of TEE was 6.62±0.04 in 2min of exercise. From 4min to the end of exercise, the intracellular pH of both TWE and TEE returned over time.
Our result showed that the PCr/(Pi+SP) ratio of both TWE and TEE returned with time during exercise, and the ratio of TWE maintained a lower level than that of TEE during exercise. To maintain a lower level of energy of TWE could stimulate synthesis of muscle protein. Therefore, TWE might be more effective to increase muscle volume or improve muscle atrophy than TEE.
The energy level of TEE returned to a greater extent than that of TWE during exercise. However, tension of both TWE and TEE did not return. This fact suggests that TEE may raise threshold intensity of excitation-contraction coupling during exercise to a great degree compared with TWE, hence, continuous TEE may increase resistance to a raised threshold intensity. Based on this fact, TEE might be more effective to improve muscle weakness and increase muscle tension than TWE.

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[in Japanese]

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