The purpose of this study is to explore the feasibility of applying the CSA scale to measure the individual spatial operation ability of operators using a control-display device. Because competent operators may be able to reduce the possibility of serious accidents from the control room, it is important to be able to effectively measure the individual differences among operators. For this reason, we adopted a 2 (cognitive styles)×2 (control-display pairing patterns) split-plot design for our experiment. This paper examined the differences between the performances of participants with field-dependent (FD) cognitive styles and field-independent (FI) cognitive styles in control-display pairing tasks, and the correlation between CSA scores and performances. The results of the experiment indicated that the CSA scale is capable of distinguishing between employees in their capacity to operate control-display devices effectively. Therefore, it is suggested that together with other performance measurement criteria, the CSA scale should serve as a measurement criterion to help screen control room operators. This would reduce the occurrence of possible errors and help to improve control room safety.

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Quantitative ultrasound (QUS) parameters of the calcaneus and bone resorption markers predict osteoporotic fractures. High levels of physical activity have positive effects on bone health. The purpose of this cross-sectional study was to investigate the effects of daily walking activity (number of steps taken), as an outcome of physical activity, on QUS parameters of the calcaneus and urinary deoxypyridinoline (DPD) in elderly Japanese women. The subjects were 113 postmenopausal women aged 60–85 years. The speed of sound (SOS), broadband ultrasound attenuation (BUA), and the stiffness index (Stiffness) of the calcaneus were measured with A-1000 (GE-Lunar, USA). Spot urine samples were collected between 09:00 and 10:00, and the levels of urinary DPD were measured. The subjects were instructed to wear a pedometer during waking hours for 7 consecutive days. In univariate analyses, steps/day significantly decreased with aging (r=−0.306, p<0.001). Steps/day showed significant positive correlations with SOS (r=0.252, p<0.01) and Stiffness (r=0.258, p<0.01). There was a significant decrease in DPD with steps/day (r=−0.262, p<0.01). These effects of walking on QUS parameters and DPD remained significant after adjustment for confounding factors by multiple regression analyses. We conclude that high levels of walking activity may be effective in both maintaining the levels of QUS parameters and reducing bone resorption, and hence preserve bone health in elderly women.

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The present study was to investigate whether increasing thermal insulation affects thermal sensation in the hands and feet; and whether aging is an influential factor in the relationship between thermal responses and subjective thermal perceptions. Six young males (YM), 5 young females (YF), 6 elderly males (OM), and 6 elderly females (OF) volunteered as subjects. Subjects conducted two trials at a constant air temperature of 19°C: One condition included thermal underwear (19CUW) while the other did not (19C). The results showed that (1) rectal temperature (T_re) did not show any significant differences between conditions with and without thermal underwear. The T_re of the OF was greater than that of the YF (p<0.05) for the 19C condition, while the young and elderly male groups showed similar values. (2) The hand and foot skin temperatures (T_hand, T_foot) were greater in the OF than in the YF group for the 19C condition (p<0.001). (3) For overall thermal sensation, the OF group was less sensitive to differences between the 19CUW and 19C condition, when compared with the old male and young groups. (4) For thermal sensation in the hands and feet, the elderly groups were less sensitive than the YF. In particular, all elderly females felt the hands were thermally neutral, even in the 19C condition. (5) Hand thermal sensation for the OF group appeared to be irrelevant to T_hand. (6) Thermal preference of the elderly groups did not change significantly after adding thermal underwear compared to the young group. In conclusion, wearing thermal underwear in mild cold did not affect local skin temperatures and thermal sensation in the hands and feet for the elderly male and female groups. Adding thermal underwear in mild cold affected the hand skin temperature and thermal sensation of the young female group. In particular, elderly females had specific features concerning local skin temperatures and thermal sensations distinguished from elderly males and young groups.

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In this study, we described the joint angle changes of the trailing leg during the compensatory step used to recover balance following a forward slip while walking. Fifteen healthy young males walked on a walkway which incorporated a movable platform to simulate a forward slip while walking. In 12 out of the 15 subjects, the trailing leg was rapidly lowered during the swing phase and was placed on the ground behind the slipping foot following the onset of the slip. Time taken for the onset of the slip to the placing of the trailing foot was 0.28±0.03 s. The amount of hip flexion lessened after 52% of the normalized time, with 0% being the onset of the platform movement and 100% representing the placing of the trailing foot on the ground. The flexed knee began to extend at 72% of the normalized time, which continued until the foot was firmly placed. The plantarflexed ankle began to dorsiflex at 56% of the normalized time, the angle of which peaked at the moment the toe made contact with the walkway again—the end of the movement. These findings aided us in understanding the mechanism underlying the compensatory step to recover the loss of balance caused by a forward slip while walking.

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The acquisition of soft tissue measurements, fat (chemical) or adipose tissue (morphological) quantities, is essential in clinical research and nutritional status and its associated health risks. This has led to a proliferation of methods for the in-vivo determination of body composition. None of the indirect in-vivo approaches to estimate body adipose tissue has been validated against direct dissection data except for the skinfold.
Since the development of DEXA as a measurement tool of bone density and mineral content for the detection of osteoporosis, it became a tool for measuring regional and whole body masses, lean tissue, and fat. A number of validation attempts have been made, however mostly against other indirect in-vivo techniques.
The purpose of this study was to conduct an in-vitro validation and quality control of the data acquisition of DEXA using dissection as the criterion method. Fourteen porcine hind legs were scanned with DEXA, weighed in air and water and dissected into skin, adipose tissue, muscle and bone. Normal distribution, means, standard deviations, paired student t-test, Pearson correlation coefficients, interclass correlations test, and a Bland-Altman plot were used. The results show systematically good to excellent correlations between DEXA and dissection data acquisition (r²=0.75 to 0.99), but absolute indirect DEXA and direct dissection values are significantly different (p<0.05). DEXA overestimates total weight, lean mass, and fat free mass and underestimates both mass and % adipose tissue.
DEXA provides erroneous values for bone density. Data produced by DEXA are morphological, not chemical values, as claimed by the manufacturer.
This ‘pilot’ study indicates that a ‘simple’ combination of skin, adipose tissue, muscle, and bone from hind legs may give an incomplete picture of reality as one needs to measure viscera, connective tissue, and air pockets of the body. Validation studies with intact bodies are advised.

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The purpose of this study was to examine the timing of recovery of the high-frequency (HF) component of heart rate variability (HRV) after exercise in female distance runners using frequency analysis of HRV. Twenty-two female young (n=11; YG) and middle-aged (n=11; MG) distance runners participated in this study. The two groups performed incremental cycle exercise with progressive intensity until exhaustion. The R–R intervals were processed by the maximum entropy method for determination of HF power on successive 7-second segments of 70 seconds of the recovery period. In the YG, the HF power of the second 7-sec segment showed significantly higher values than the 7 sec before cessation of exercise (p<0.005), whereas the MG exhibited significantly higher values in the third segment (p<0.005). The YG indicated significantly higher HF power than the MG in the fifth segment (p<0.0045). These findings suggested the occurrence of parasympathetic reactivation at an earlier period compared to the previous findings. Multiple influences of various factors including the subjects' characteristics to HF recovery were suggested. However, the detection of the timing of HF recovery despite the duration of sharp change in HR indicated that HRV was an effective evaluation technique for determination of autonomic control immediately after exercise.

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The aim of this study was to investigate the impact of caregiver knowledge and experience on muscle activity and perceived exertion while repositioning bedridden patients. Subjects were 40- to 65-year-old female caregivers divided into novice and experienced groups. Subjects from both groups performed home-care repositioning techniques on bedridden patients while muscle activity was recorded via electromyogram. Recordings were made from four muscles on the subjects' dominant side: the latissimus dorsi, the biceps brachii, the erector spinae, and the rectus femoris. The subjective burden involved in repositioning was also assessed using the rate of perceived exertion (RPE) and visual analog scales (VAS). Rectus femoris percentage of maximum voluntary contraction (%MVC) values were significantly lower than latissimus dorsi, erector spinae, and biceps brachii values in the novice group. %MVC values from the latissimus dorsi and biceps brachii were significantly higher among the novice group compared to the experienced group. RPE ratings from the novice group were significantly higher than those of the experienced group, and there was a non-significant trend for higher VAS values for the low back, arms, and legs in the novice group compared to the experienced group. Novice caregivers tended to change the patient's position by pulling with the upper limbs without using the lower limbs. In contrast, experienced caregivers exerted less energy by communicating with the patient and utilizing the patient's own movements. They used large, distributed muscle groups that effectively harnessed body mechanics and prevented excess exertion.

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