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Volume 39 (1990)
- Issue 6 Pages 399-
- Issue 5 Pages 293-
- Issue 4 Pages 231-
- Issue 3 Pages 155-
- Issue 2 Pages 93-
- Issue 1 Pages 1-
Volume 39, Issue 2
Displaying 1-9 of 9 articles from this issue
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[in Japanese]1990 Volume 39 Issue 2 Pages 93-98
Published: April 01, 1990
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSDownload PDF (991K) -
SATOSHI MATSUNAGA, TSUGUTAKE SADOYAMA, HIROFUMI MIYATA, SHIGERU KATSUT ...1990 Volume 39 Issue 2 Pages 99-105
Published: April 01, 1990
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSWe investigated the effects of strength training a muscle fiber conduction velocity in biceps brachii of 7 male students. The subjects were trained to exhaustion by 60% of maximum isotonic voluntary contraction with 3 sets/day, 3 days/week for 16 weeks. The muscle fiber conduction velocity was measured with a surface electorode array placed along the muscle fibers, and calculated from the time delay between 2 myoelectric signals recorded during a maximal voluntary contraction. Upper arm girth significantly increased (p<0.01), from 29.2±1.4 cm (means±S. D.) to 30.6±1.5 cm. On the other hand, training induced no significant changes in upper arm skinfold. A significant difference between pre- and post-training was found in maximum isotonic strength (p<0.01) . Although maximum isometric strength showed no significant changes with training, there was a tendency for an increase in maximum isometric strength. Muscle fiber conduction velocity increased by 3.5% during training period, but this was not significant. These results suggest no effects of strength training on muscle fiber conduction velocity.View full abstractDownload PDF (859K) -
JUN-ICHI MAEDA, TAKASHI TAKEMIYA1990 Volume 39 Issue 2 Pages 106-113
Published: April 01, 1990
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe effects of the gravitational potential energy change (GPEC) and the thermal stress on finger microvascular responses were studied by laser Doppler and ultrasonic Doppler flowmetry. Seven healthy male subjects, aged 21 to 31 yrs, participated in the experiment after giving their informed consent. The hand was moved upward (about 60 cm) or downward (about 55 cm) from the heart level to change the vascular transmural pressure of the finger (GPEC) . Sensors of laser Doppler and ultrasonic Doppler flowmeters were attached to the lateral side of the first finger and the skin surface over the radial artery, respectively. Experimental room temperature was maintained at 24°C. Laser Doppler flow (LDF) was decreased at an elevated and lowered arm position. The pulsatile component of LDF, evaluated by the difference between systolic and diastolic LDF, increased when the arm was elevated, but it showed no significant changes when the arm was lowered. Mean blood velocity (MBV) and diastolic blood velocity (DBV) of radial artery decreased when the arm was elevated, whereas the pulsatile blood velocity (PBV), evaluated by the difference between systolic blood velocity (SBV) and DBV, were increased. At the lowered arm position, SBV and PBV decreased significantly, but DBV showed no significant changes. The thermal stress (43°C, 10 min) increased the PBV when the arm was elevated, but the PBV diminished the decreasing rate when the arm was lowered.
These results suggest that the measurements used may be useful for the analysis of arteriolar compliance and microvascular response to the change of transmural pressure pro-duced by the gravitational potential energy change.View full abstractDownload PDF (934K) -
KUMI AKATAKI, KATSUMI MITA, TOSHIAKI MIYAGAWA, NAOTAKA ISHIDA1990 Volume 39 Issue 2 Pages 114-119
Published: April 01, 1990
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSEighteen persons with both severe mental retardation and severe physical disabilities and ten normal persons participated to investigate cardiovascular response to hydrostatic pressure stress using supine and sitting positions. All of the handicapped subjects lay down on the bed during the entire day. They were classified into three groups. That is, the first group (LD) had not opportunity of sitting passively in daily living at all. Another two groups were given opportunity of sitting. In addition, the second group (ST 1) was unable to sit and stand independently in the past but the third group (ST 2) was able. The LD showed unchanged heart rate and decreased blood pressure with reduced peripheral blood flow in the sitting position. This suggested that serious lower function or dysfunction in both central and peripheral circulatory system. The cardiovascular function of the ST 1 was characterized by elevated heart rate and lowered blood pressure. This seemed to indicate lower baroreflex control to the peripheral vascular system. The ST 2 demonstrated similar function to the normal persons. The cardiovascular regulation in the severely handicapped persons may depend on opportu-unity of taking orthostatic posture in daily living in addition to motor adility in the past.View full abstractDownload PDF (705K) -
SEIICHI NAKAI, AKIRA YORIMOTO, TAKETOSHI MORIMOTO1990 Volume 39 Issue 2 Pages 120-125
Published: April 01, 1990
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSIndexes to prevent heat casualties have been reported by many investigators based on different temperature scales including wet bulb temperature, wet bulb globe temperature, dry bulb temperature and so on. In this report, environmental temperature of an athletic field in Tokyo area was monitored in summer of 1981 to 1985, using natural wetbulb temperature (NWB), natural drybulb temperature (NDB), globe temperature (GT) and air velocity (A. V.) and WBGT (Wet Bulb Globe Temperature Index) was calculated, from NWB, GT and NDB on the result.
The highest temperature observed was 33.2°C in WBGT, 28.0°C in NWB and 37.5°C in GT. Highly significant correlations were obtained between WBGT and other parameters, than for A. V.
Based on the regression equation between WBGT and NWB, preventive measures for athletes in hot conditions were compared.View full abstractDownload PDF (683K) -
SHIGERU MORIMOTO, MIFUYU KAMO1990 Volume 39 Issue 2 Pages 126-132
Published: April 01, 1990
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSIn the present study, we investigated the wave form of human single motor unit potentials recorded monopolarly using a surface electrode. Each motor unit potential consists essentially of three phases. However, we found a non-conductive component in the motor unit potentials, defined as“late positive deflection”. This non-conductive component appeared in and overlapped the third positive phase of the motor unit potential and showed the following properties 1) When surface electrodes were placed on the skin surface overlying the m. vastus medialis in line with the direction of muscle fibers belonging to the observed motor unit, the peaks of the non-conducting components were synchronized with each other and their amplitude increased exponentially with the distance from the motor end plate. 2) When the action potential was conducted to the myotendinous junction, the potential spread to the tendon electrotonically. The peak of the non-conducting component was also synchronized with the electrotonic potential. 3) The amplitude of the non-conducting component increased depending on the developed tension.
These results suggest that the appearance of the non-conducting component was due to synchronization of motor unit potentials that had just arrived at the myotendinous junction with the observed motor unit potential. When the motor unit potentials arrived at the myotendinous junction, the current flow to the forward local circuit of the action potential was cut off because of the high impedance of the tendon. Therefore the forward current flow was to be flowing the backward local circuit. The number of recruited motor units increased depending upon the developed tension. When many motor units fired randomly, their volume conducted-potentials canceled each other in the region of the muscle fiber. At the myotendinous junction, however, the directions of current flow due to the action potentials elicited by many motor units coincided and intensified each other.
Therefore, it is considered that this“late positive deflection”carries information on the number of motor units activated i. e., “recruitment”.View full abstractDownload PDF (5072K) -
AKIHIRO NAGATA, ETSUO FUJIMAKI, KEIZO SAKAMOTO, SETSURO KURIYAMA, TOSH ...1990 Volume 39 Issue 2 Pages 133-137
Published: April 01, 1990
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSIf the traumas treated at Ishiuchi Clinic of Showa University during the past 31 years from 1957 to 1988 are classified by topical site and type, the traumas in the knee and ankle joints are seen in many cases, occupying totally 53% of the total traumas. Compared with these, the traumas in the hip joint are relatively rare, and particularly, the cases of traumatic dislocation of the hip joint are extremely rare articular traumas. The subject cases were 6 males and 5 females.
The traumatic mechanisms have been elucidated, and concurrently, super selective angiography was performed on the medial circumflex arteries in 8 cases to determine angiographically the time when loading began.
There are many cases whose posterior dislocations were presumably caused by a mechanism that, while the tibia is fixed by skiing boots in a position including forward in angles slightly wider than 90°, flexion and rotary strengths applied to the hip joint are much strong at the skier's position with extended knee joint because the safety binding does not come loose at the fall of the body forward.
The superior retinacular arteries are said to be very important remification of the medial circumflex femoral artery which supplies 2/3-3/4 of blood stream to the outside of the loaded epiphysial region. What are presumed as the causes for the ineffective and defective angiograms are (1) compression by hematoma, (2) extended SRA and (3) rupture of SRA. The time of loading to begin was found as 2 months in the case with favorable angiograms of SRA and 4 months in the cases with ineffective or defective angiogram.View full abstractDownload PDF (3975K) -
[in Japanese]1990 Volume 39 Issue 2 Pages 138-143
Published: April 01, 1990
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSDownload PDF (770K) -
1990 Volume 39 Issue 2 Pages 144-153
Published: April 01, 1990
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSDownload PDF (1351K)
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