The purpose of the present study was to determine whetehr differences exist between nine experimental conditions mixing 10°, 40°and 70°of hip joint angles with knee joint angles, when thirteen subjects performed the same response task. In the experiment 1, each subject was asked to stand on the inside two of the four mat switches (500×700 mm) and keep the assigned joint angles during a second of preparatory period. After the period, each subject was asked to respond with a step out on either the right or the left outside mat switch as quickly as possible. Then the data was collected analyzing the whole body choice response time (RESPONSE TIME) defined as the interval time from the signal to respond with step out, the whole body choice reaction time (REACTION TIME) defined as the interval time from the signal to reaction with lifting the leg for responding to the step out, and the movement time (MOVEMENT TIME) defined as the interval time subtracting RESPONSE TIME from REACTION TIME. Moreover, in the experiment 2, the data was collected and analyzed from the onset time of various forces from the two force platforms on which each subject stood instead of the mat switch and EMG which was led from the right side of m. rectus femoris, m, biceps femoris, m. gastrocnemius, m. tibialis anterior and the left side of m. quardriceps femoris, during performance of the response task. The results were as follows:
1. The subjects' posture with each 70°flexion of the hip and the knee joint revealed the shortest RESPONSE TIME, because of the shortened MOVEMNT TIME, compared with the other posture. Conversely, the posture with 70° flexion of the knee joint showed an expanded REACTION TIME.
2. The knee joint angle was an important factor effecting both REACTION TIME and MOVEMENT TIME, rather than the hip joint angle for the task of the experiment, since flexion of the knee joint expanded the REACTION TIME, but shortened the MOVEMENT TIME.
3. The result of the force platform measurements indicated that the posture with each 70°flexion of the hip and the knee joint was shorter than that with each 10°flexion of them at the onset time of the first reaction force after the reaction signal, and that the order of response for the task was beginning at the leg for responding, followed by the other leg for keeping stability.
4. Conclusive evidence for a shortened RESPONSE TIME was found in the facilitation of the central nervous system, which revealed the preliminary muscle activity and the stabilizing of the posture.

This study was to investigate the effects of balance exercises on among static, dynamic and reactive balance ability in community-dwelling older women. Participants comprised 26 community-dwelling older women in Japan, randomized for age and gait speed to the exercise group (n=13) or the control group (n=13). The exercise group performed structured balancing exercises on the sponge and the G ball, once weekly for 24 weeks. The control group performed stretching exercises once per month. Static balance ability was assessed by measuring postural sway and standing on one leg; dynamic balance ability was assessed by measuring functional reach, timed up and go, and gait; and reactive balance ability was assessed using the EquiTest. We also measured knee and ankle strength using an isokinetic machine.At baseline, the two groups were well matched in physical characteristics and in all balance ability and strength tests. After 24 weeks, step length of preferred speed walking (p=0.049) only improved, and peak torque of knee flexion (p=0.050) tended to improve in the exercise group. Any correlations were not found between step length of preferred speed walking and knee flexion strength.These results suggest that these structured balance exercises are effective in improving dynamic, but not static or reactive balance ability. Improvements in dynamic balance ability were not dependent on improved muscle strength.

The aim of this study was to compare co-contraction of ankle muscles between older and young adults performing a voluntary sway task, and identify any relationships between co-contraction, balance ability and muscular strength. The task involved displacement of the center of mass backwards and forwards continually during upright stance under three amplitude conditions, large, small and preferred, with sway speeds of slow, medium and fast. The participants comprised 17 older (64.1±2.9 years) and 14 young (21.3±3.3 years) women. Electromyographic recordings were obtained from the tibialis anterior and the medial gastrocnemius muscles during task performance to calculate the co-contraction index (CCI) and evaluate the relative level of co-contraction of antagonist muscle. Additional measurements were obtained from balance tests including body sway tests, functional reach, gait tests, and the EquiTest (Neurocom), and also muscular strength of plantar flexion and dorsiflexion. The CCI was highest under large sway amplitude, but did not differ among sway speeds. The CCI was higher in the older group (23%) than in the young group (15%). Multiple regression analysis revealed that the CCI correlated with body sway in the EquiTest and functional reach, and dorsiflexion strength. Therefore, this study suggested that co-contraction of ankle muscles increased with aging and related to not only static and dynamic balance abilities, but also ankle dorsiflexor strength.

This study was carried out in order to compare stride time (gait) variability of walking not only between young and older adults, but also between “fallers” and “non-fallers”. Moreover, this study aimed to clarify the relationship between stride time variability, balance ability, muscular strength and fall experience. The subjects were 12 young women aged 21.2±2.2 years (young group) and 27 older women aged 66.6±4.4 years (older group). The older group included 14 fallers and 13 non-fallers. They wore an accelerometer on their back and walked at a slow, preferred or fast pace. The time of heel contact was detected by acceleration waveform, and stride time was estimated. The stride time variability was computed by the coefficient of variance (CV) of stride time. The subjects underwent balance tests and muscular strength tests. The CV of stride time at the preferred and fast pace were significantly larger in the older group than in the young group, even though there was no difference in any of the gait speeds between the two. The CV of stride time was significantly larger in fallers than in non-fallers at the fast pace. Path analysis showed that fall experience was affected by an increase in the CV of stride time and decreased balance ability, but less affected by decreased muscular strength. Therefore, this study suggested that stride time variability when walking fast is useful as an early assessment of fall risk in middle-aged and elderly people and that fall experience was affected by stride time variability and balance ability.

A 22-year-old man was referred to our medical center with an impending rupture of an aneurysm of the descending thoracic aorta. Blood pressure was 180/110mmHg in the right arm but 110/60mmHg in the right foot. The diagnosis was confirmed by chest Xray, enchanced computed tomography and aortogram. Five days later, the chest Xray showed massive effusion in the left pleural cavity. Surgery was immediately performed via a left thoracotomy. Five hundred ml of bloody fluid was found in the pleural cavity but the site of bleeding could not be identified. The aneurysm was 7×10cm in size. Under percutaneous cardio pulmonary support, the aneurysm was replaced by a 22mm Gel-Seal Dacron vascular graft. The intima and the media of the aneurysm were lacerated longitudinally at the region receiving jet flow from isthmus, There was blood coagula between the media and adventitia. During replacement, activated clotting time was maintained at 200∼300sec. As a result, bleeding was limited to 200ml. The postoperative course was uneventful with little difference in pressure between the right arm and right foot.

A study was conducted to determine the effect of aging on motor ability and to establish a test battery for physical fitness in the elderly. The subjects were 150 men aged 18 to 83 years. The test items examined were selected, according to Fleishman's list of motor abilities; (1) trunk flexion, (2) grip and isometric knee extension strength, (3) postural sway with eyes open and closed, (4) step test, (5) walking test at preferred and maximum speeds, (6) simple visual reaction time, (7) peg-board test, (8) finger tapping test at maximum rate and in time to metronome sounds. Performances for the test items, except for preferred walking speed and coefficient of variation in finger tapping at 5 Hz, showed significant decreases with aging. The decrease in motor performance at age 80 years relative to the level at age 20 years was less than 30% for finger dexterity and reaction time, 40-60% for muscle strength, maximum walking speed and the step test, and over 70% for trunk flexion and postural sway with eyes closed. A test battery composed of trunk flexion, grip strength, knee extension, step test, walking as fast as possible, postural sway with eyes closed, and finger tapping, is therefore recommended for assessing the effect of aging on physical fitness.

A motor performance test was administered to elderly adults in Koganei City and Nangai Village of Japan as the baseline study of Tokyo Metropolitan Institute of Gerontology, Longitudinal Interdisciplinary Study on Aging (TMIG-LISA) . The participants in this study totaled 405 (183 males and 222 females) aged 65 to 84 from Koganei City, and 734 (295 males and 439 females) aged 65 and over from Nangai Village. The test consisted of measurement of grip strength, one-leg stand-ing, walking at preferred and maximum speeds, and finger-tapping. All motor performances examined were higher among males than females, and they all deteriorated with aging. A regional difference was found in terms of motion speed abilities: finger-tapping rate and walking speed were higher among urban residents than rural residents. Individual differences (coefficient of variation) in the motor ability increased with aging, and reached 106% (maximum tapping rate in female) to 290% (maximum walking speed in female) of those in the twenties. Significant correlations between motor abilities were detected indicating that the specificity of the motor ability found in the young may not account for older adults.

PURPOSE: We recently demonstrated the morphology of the anococcygeal ligament. As the anococcygeal ligament and raphe are often confused, the concept of the anococcygeal raphe needs to be re-examined from the perspective of fetal development, as well as in terms of adult morphology. MATERIALS AND METHODS: We examined the horizontal sections of 15 fetuses as well as adult histology. From cadavers, we obtained an almost cubic tissue mass containing the dorsal wall of the anorectum, the coccyx and the covering skin. Most sections were stained with hematoxylin and eosin or Masson-trichrome solution. RESULTS: The adult ligament contained both smooth and striated muscle fibers. A similar band-like structure was seen in fetuses, containing: 1) smooth muscle fibers originating from the longitudinal muscle coat of the anal canal and 2) striated muscle fibers from the external anal sphincter (EAS). However, in fetuses, the levator ani muscle did not attach to either the band or the coccyx. Along and around the anococcygeal ligament, we did not find any aponeurotic tissue with transversely oriented fibers connecting bilateral levator ani slings. Instead, in adults, a fibrous tissue mass was located at a gap between bilateral levator ani slings; this site corresponded to the dorsal side of the ligament and the EAS in the immediately deep side of the natal skin cleft. CONCLUSION: We hypothesize that a classically described raphe corresponds to the specific subcutaneous tissue on the superficial or dorsal side of the anococcygeal ligament.
Aged, 80 and over ; Anal Canal/*anatomy & histology/embryology ; *Cadaver ; Female ; *Fetus ; Humans ; Male ; Muscle, Smooth/*anatomy & histology/embryology ; Rectum/*anatomy & histology/embryology

PURPOSE: It is still unclear whether the longitudinal anal muscles or conjoint longitudinal coats (CLCs) are attached to the vagina, although such an attachment, if present, would appear to make an important contribution to the integrated supportive system of the female pelvic floor. MATERIALS AND METHODS: Using immunohistochemistry for smooth muscle actin, we examined semiserial frontal sections of 1) eleven female late-stage fetuses at 28-37 weeks of gestation, 2) two female middle-stage fetus (2 specimens at 13 weeks), and, 3) six male fetuses at 12 and 37 weeks as a comparison of the morphology. RESULTS: In late-stage female fetuses, the CLCs consistently (11/11) extended into the subcutaneous tissue along the vaginal vestibule on the anterior side of the external anal sphincter. Lateral to the CLCs, the external anal sphincter also extended anteriorly toward the vaginal side walls. The anterior part of the CLCs originated from the perimysium of the levator ani muscle without any contribution of the rectal longitudinal muscle layer. However, in 2 female middle-stage fetuses, smooth muscles along the vestibulum extended superiorly toward the levetor ani sling. In male fetuses, the CLCs were separated from another subcutaneous smooth muscle along the scrotal raphe (posterior parts of the dartos layer) by fatty tissue. CONCLUSION: In terms of topographical anatomy, the female anterior CLCs are likely to correspond to the lateral extension of the perineal body (a bulky subcutaneous smooth muscle mass present in adult women), supporting the vaginal vestibule by transmission of force from the levator ani.
Anal Canal/*anatomy & histology/embryology ; Female ; Fetus/anatomy & histology ; Humans ; Male ; Muscle, Smooth/*anatomy & histology/embryology ; Pelvic Floor/anatomy & histology ; Sex Characteristics ; Vagina/*anatomy & histology/embryology