The purpose of this study was to examine differences in the inhibitory effect of disuse atrophy as a result of intermittent weight bearing in terms of the dynamics of nuclei in rat soleus muscle. Disuse muscle atrophy was induced by hindlimb suspension for two weeks. Forty-nine male Wistar rats (body weight: 190-228 g) were divided into the control group (CON) and the experimental group. The experimental group was subdivided into four groups: hindlimb suspension alone (HS), weight bearing for 10 minutes × 4 times/day (W10), weight bearing for 20 minutes × 2 times/day (W20), and weight bearing for 40 minutes × one time/day (W40). In addition to histochemical examination, this study examined both cell proliferation and apoptosis in terms of the dynamics of myonuclei immuno-histochemically. The mean cross-sectional area of muscle fibers demonstrated the effect of weight bearing. The number of proliferating myonuclei per 100 muscle fibers was decreased in the experimental groups as compared with CON. Proliferating myonuclei in W10 and W40 were more than HS, indicating the effect of weight bearing. Apoptotic myonuclei was increased in the experimental groups as compared with CON. This parameter in W10 and W40 were statistically not significantly different from CON, suggesting that these weight bearing methods can prevent the loss of myonuclei by apoptosis. However, W20 was not significantly different from HS in terms of the dynamics of myonuclei. This suggests that weight bearing for W20 was ineffective. The results in this study indicated the possibility of inducing different effects by the frequency of weight bearing.
This study aimed to determine the test-retest reliability and inter-tester reliability of kinematic measures in a three-dimensional gait analysis system. Using a VICON 140TM three-dimensional motion analysis system, kinematic data for lower extremities during walking were collected by 2 testers (senior physical therapists) for 6 unimpaired adults (age = 20 to 52; mean = 35.2 ± 6.2). The study was conducted using a repeated measures design consisting of two testing sessions per day on two separate testing days. The reliability of joint angle data collected by two different testers on two different days was compared for 2 sessions (days) × 2 testers × 5 trials. Skin markers were placed on 15 defined pelvis and lower body locations in accordance with the VICON Clinical Manager model. Prior to the study commencing, the two physical therapists practiced marker placement for a 3 month period. The first measurements (T1) were carried out by two testers on the same day. The second measurement session (T2) was performed within two weeks using an identical procedure. Coefficients of multiple correlation (CMC) were calculated to evaluate the consistency between the kinematic variables across testers and sessions. Both test-retest and inter-tester reliability were high for motion in the sagittal plane (Ra= 0.971 to 0.994), the frontal plane (Ra= 0.759 to 0.977), and the transverse plane (Ra= 0.729 to 0.899), excluding pelvic tilt. Reduction of variability of marker placement appears possible with standardization and understanding of the placement method. These findings provide evidence of the reliability of using three-dimensional motion analysis for measuring human gait.
The relationship between exercise capacity and left ventricular function has been evaluated in 35 patients with acute myocardial infarction (34 males and 1 female; mean age 55.5 ± 7.1 years). Single photon emission computed tomography (SPECT) was used to measure left ventricular function in the acute phase (4.9 ± 2.2 days after onset) and the chronic phase (188.5 ± 22.9 days after onset). More than 10% left ventricular dilatation from the acute phase to the chronic phase was defined as remodeling (RM) and the subjects were divided into 2 groups: RM and non-RM. Cardiopulmonary exercise testing was performed at 1 month (1M), 3 months (3M) and 6 months (6M) after onset. In the RM group, anaerobic threshold (AT) and peak oxygen uptake (Peak VO2) did not change significantly. In the non-RM group, AT was 15 ± 1 (ml/min/Kg) at 1M, 16 ± 2 at 3M and 18 ± 4 at 6M. Peak VO2 was 26 ± 3 (ml/min/Kg) at 1M, 30 ± 2 at 3M and 32 ± 3 at 6M. Both parameters in the chronic phase increased significantly compared with those at 1M (p<0.002 and p<0.0001). Thus, change in exercise capacity would correlate with change in left ventricular function.
A cross-sectional study was designed for this investigation using a healthy Japanese population. The objectives of this study were to confirm gender and age-related differences in axial alignment of the lower limb, and to investigate the correlation between femorotibial angle and axial alignment of the lower limb among a healthy Japanese population. Although axial alignment of the lower limb has been defined as one of the associating factors for osteoarthritis of the knee along with varus and valgus deformity, the results in the literature are inconsistent. Since there is gender difference in femorotibial angle, axial alignment of the lower limb should show the difference if it is an associating factor for osteoarthritis of the knee. Few studies have been conducted to investigate gender difference in axial alignment of the lower limb. One hundred and forty four healthy Japanese subjects took part in the study. Reliable clinical methods of measuring femoral torsion, tibiofibular torsion, rotational range of motion of the hip and knee joints, and femorotibial angle were employed utilizing a digital inclinometer. Two way ANOVA and Pearson product-moment correlation analysis were used for statistical analyses. Axial alignment of the lower limb was different between genders (p<0.05). An age-related difference was also shown in hip rotation (p<0.05). Further, the femorotibial angle was significantly correlated with hip and knee joint rotation (p<0.05) in older males and younger females. This study implied that axial alignment of the lower limb may be related to deformity of the knee joint.