RESUMO
<p>The purpose of this study is to clarify the effect of hip, knee, and ankle joint contractures on the joint angle and joint moment during standing posture using a mechanics simulation. A two-dimensional segment model (trunk, thighs, shanks, and feet) was created, and the standing postures for various hip, knee, and ankle joint angle configurations were generated (i.e. 743 types of standing postures). The hip, knee, and ankle joint contractures were reproduced by manipulating the joint stiffness, and optimal standing posture when the minimum value of the sum of muscle activities was obtained. When the hip joint contracture was developed during standing posture, the hip and knee flexion angle, and the hip and knee extension moment increased as well. When the knee joint contracture was developed during standing posture, the hip and knee flexion angle, ankle dorsiflexion angle, and the knee extension moment increased. When the ankle joint contracture was developed during standing posture, the hip flexion angle and the ankle plantarflexion angle increased and the knee joint was extended; the hip extension moment and knee flexion moment also increased. The findings of this study may help to improve abnormal standing posture through physical therapy.</p>
RESUMO
Objective: The physiological changes of the respiro-circulatory functions between skilled subject and unskilled subjects during the practice of Up-right Standing Posture of Shaolin Internal Qigong were compared. Method: The heart rate (HR), maximum oxygen uptake (VO2), respiratory efficiency (RE), and respiratory rate (RR), blood pressure, and lactic acid in the blood were measured.Results: The high correlations between the HR and the VO2 values obtained from the exhaustion test were observed in all subjects. The higher values than at the rest were observed in the average HR and the average VO2 during practicing the Up-right Standing Posture both in the skilled subject and unskilled subjects. However, both HR and VO2 levels were almost constant during the practice in both the skilled subjectand unskilled subjects. The RE values changed in the time course of the practice, whereas the RR values were almost constant during the practice. The average RE showed different patterns between the skilled subject and unskilled subjects, the former increased and the latter decreased their RE levels.In addition, the average values of systolic and diastolic blood pressure of the skilled subject increased each 10 mmHg approximately at pre- and post- Up-right Standing Posture, and the increasing tendency was also recognized in the unskilled subjects. The values of the lactic acid in the blood of the skilled subject increased slightly, whereas the average values of the unskilled subjects increased by 3.4 mmol/1. Conclusion: Shaolin Internal Qigong could improve respiratory efficiency by the maximum isometric muscle contraction while the skilled subject maintained natural breathing. In addition, Shaolin Internal Qigong was considered to influence the reflex system because it inhibited both blood pressure increase and respiratory rate change. Shaolin Internal Qigong fit very well with Tuina doctor training course for promoting the physical ability and manipulation abilities of them.
RESUMO
We carried out three measurements on 12 healthy men to investigate the positional perception in forward or backward flexions of the trunk while standing. In measurement (I), the subjects reproduced the target angle perceived by forward flexion (FF) or backward flexion (BF) of the trunk with their eyes blindfolded. In measurement (II), the subjects first visually perceived the angle shown by an angular, indicator, and then reproduced it by manually by operating the indicator with their eyes open. In measurement (III), the subjects first visually perceived the angle shown by an angular indicator, and then expressed the target angle by FF or BF with their eyes blindfolded. In measurements (I) and (III), indication of the target angle was set at in 5° increments from 5° to 60° in FF, and from 5° to 30° in BF, and in measurement (II) from 5° to 60°. The ability of positional perception was evaluated using the constant error (CE) and the absolute error (AE) of the reproduced or expressed angle.<BR>In measurement (I), CE was small for all target angles, ranging from -0.2°to 2.6°in FF and from 0.3°to 1.6°in BF. However, CE from 5° to 25°in FF was significantly positive. In BF, significant CE was not recognized for any target angles, and AE at each target angle was smaller than that in FF. These results suggest that the sensitivity of positional perception of the trunk in FF is relatively low for small target angles which are close to the quiet standing position.<BR>In measurement (II), CE was very small for all target angles, ranging from -1.2° to 0.9°. Significant CE was recognized only at 10°, 20°and 55°. AE was also small for all target angles, ranging from 0.5° to 1.8°, and no significant difference in AE was recognized among the target angles. These results suggest that visual perception, memorization and recall of the target angle is well retained.<BR>In measurement (III), a relationship between the target angle and the CE was shown on a negative regression line in both FF and BF. As viewed from the regression line, the angle at which the CE became zero was 36°in FF and 18° in BF. AE in target angles close to these angles was also small. This indicates that angles smaller than these are perceived as smaller than they actually are, while angles larger than these are perceived as larger than the actual ones.
RESUMO
A study was conducted to investigate the effects of a sagittal position of the body gravity center (GCP) and manual weight-load on postural control during rapid arm-lifting. The subjects were five males aged 21 to 36 years. They stood on a force plate while maintaining the GCP at 30%, 45% and 60% from the heel, regarding the fool length as 100%, and anteriorly lifted both arms spontaneously as rapidly as possible. These trials were carried out ten times under a 5 kg weight or no weight. EMGs of the biceps femoris muscle (BFM) and anterior deltoid muscle (ADM), the fluctuation of the center of foot pressure (CFP) and body motion were analyzed by focusing on their time sequences.<BR>At 45% and 60% GCP the BFM action started prior to the ADM action, whereas at 30% GCP it tended to lag behind. The lag times under no weight were 13.9±12.75 ms (mean±SD) at 30% GCP, -32.7±18.18 ms at 45% GCP and -46.0±19.40 ms at 60% GCP. Those under 5 kg weight were 15.0±11.40 ms at 30% GCP, -22.0±6.74 ms at 45% GCP and -28.9±7.63 ms at 60% GCP. These results indicate that the anticipatory action of the muscle related to postural control arises only at specific GCPs.<BR>The difference of starting points for BFM action to ADM action showed no significant difference between 45% and 60% GCP for either as 5 kg or no weight. The CFP position moving in a forward direction during arm-lifting showed a marked difference between 45% and 60% GCP. The time for arm-lifting showed a marked difference between 5 kg and no weight. These results suggest that the starting point of anticipatory muscle action related to postural control does not change according to the magnitude and time course of the distance to the body equilibrium as a result of arm-lifting.