The purpose of this study was to develop an index for the measurement of "Coping" using a sample size of 1,085 caregivers providing long-term care to elderly family members, and to clarify the relationship between mental health and the coping strategies used by these family caregivers. The index developed is a model based on the "long-term care stress coping index," which comprises two factors as subordinate concepts: "Coping through independent resolution" and "Coping through resolution involving assistance from others." With regard to this model, we studied the goodness of fit on data from an oblique model comprised of these two factors and clarified the construct validity. We also analyzed the relationship between long-term care stress coping scores and mental health scores. As a result, the goodness of fit on data from a factor model for the long-term care stress coping index reached a statistically acceptable level, indicating that the index is valid. The scores for mental health were higher for persons who used "Coping through independent resolution" more frequently and were lower for persons who used "Coping through resolution involving assistance from others" more frequently.

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The purpose of this study was to evaluate the motion and muscle activity of wheelchair users with disabilities when a car stops and starts suddenly. A subject was placed in a wheelchair fixed to a carriage and sudden stop and sudden start experiment was performed to evaluate the motion and muscle activity of the subject using a seatbelt and headrest. The sudden stops were simulated by performing front carriage crashes. The sudden starts were simulated by performing rear carriage crashes. Volunteer subjects including people with disabilities participated in the experiment. The cervical angle, the trunk angle and the muscle activity were measured. The experiment results show that the muscle reflection of disabled people was stronger than that of normal people. And, the results of these experiments demonstrated that the muscle reflection of disabled people without a seatbelt were stronger than that with a seatbelt. Both of these results show that use of seatbelt and headrest is indispensable for the safety of wheelchair users in motor vehicles. People with disabilities depend more on seatbelt and headrest than people without disability.

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The purpose of the study is to express the motion of disabled people at a sudden stop and start by using a muscle reflection model. The model was composed of two rigid links and three masses and was characterized with muscle reflection defined by Hill's equation. A sudden stop and start experiment was performed to obtain human muscle parameters and to evaluate the model. Volunteer subjects including people with disabilities participated in the experiment. The subjects were placed in a wheelchair fixed to a carriage. The cervical angle, the trunk angle and the myoelectric potential were measured. This model simulated the motion and the myoelectric potential of each subject without/with seatbelt. The simulation results were similar to experimental results. The simulation results show that safety equipments are more important for people with disabilities than for people without disability.

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The purpose of this study was to examine the effects of joint traction and position of upper limb on the pre-motor time (PMT) and motor time (MT) of quadriceps femoris. Twenty healthy male subjects participated in this study. The subjects lay supine on the torque machine with their left knee flexed at 30 degree angle. The subjects were tested for the maximum isometric extension of the left knee in an immediate response to a signal sound trigger, while holding the following eight testing positions: Two types of right upper limb positions (neutral position and PNF position with shoulder joint extension of 30 degrees, abduction of 20 degrees, internal-rotation of 70 degrees) as combined with four types of traction forces (no-load, 30N, 60N and 90N). Ten trials were measured for each testing position. PMT was measured to represent the time from the trigger to the onset of EMG, and MT, the time from the onset of EMG to the onset of the muscle torque. The results indicated major effects on the PMT in relation to traction forces and upper limb positions with significant level of interactions. No significant effect was found as to the MT The result of multiple comparison analyses showed that the PMT shortened with the increase in the traction force in the neutral position (significant differences were observed for varying PNF positions and for 0N〜all, 30N〜60N, and 30N〜90N traction forces). The PMT was significantly shorter in the PNF positions with 0N and 30N traction forces compared to that in the neutral position with the same traction forces. The PMT is known to reflect the process of the central nervous systems (CNS). These results suggest that the joint traction of upper limb and the PNF position have facilitating effects on the lower limb by arousing the CNS.

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The purpose of this study was to clarify how age related changes in the visual system contribute to declining postural stability. Fourteen healthy, elderly subjects (mean age, 67.75±6.11 years) with no history of falls and who had normal vision were recruited along with 14 young controls (mean age, 19.14±0.53 years). Postural stability when standing was assessed during anterior-posterior translations of a force plate accompanied by visual misinformation where a plain white wall was tilted towards the subjects as they swayed. Concurrent visual data was documented by an eye mark recorder and also assessed. A significant difference between age groups was found in Equi-test data for rectangle area of postural sway, and in vision data for fixation point duration, pupil diameter, convergence angle, and % eye movement velocity. For area of length, a significant difference between age groups was found only for left eyes. In the elderly, the center of gravity was larger as eye movements increased. The elderly subjects made more frequent saccadic eye movements resulting in shorter durations of point fixations causing blurred reflexive images on the retina. As the control of body movement is strongly linked to visual cues which are hindered by aging changes, performance of gait and balance changes in response to visual cues, and associated strategies to negotiate the visible environment, differ between young and elderly. We suggest that the elderly may benefit from intervention including training to control direction of gaze and other factors related to visual information processing to reduce the risk of falls.

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Imitation plays a very important role in human cognition and communicative competence. Individuals tend to imitate the hand actions of another person as if looking in a mirror (specular imitation) than with the anatomically congruent hand (anatomic imitation). We focused on the problem why anatomic imitation is more difficult than specular imitation. To understand the neural substrates of the anatomic imitation versus the specular imitation with the left or right hand, eleven normal female subjects who imitated the finger movements of an actor using the anatomically congruent or incongruent hand were examined using functional magnetic resonance imaging (fMRI). As a result, the error rate tended to be higher for anatomic imitation than for specular imitation, and the bilateral inferior frontal gyrii (IFG) and the right dorsal premotor cortex (PMd) were activated during anatomic imitation versus specular imitation, irrespective of the hand used. Especially the right IFG activity may inhibit the motor representation associated with the preferred movement of imitating the actor's hand movement as if looking in a mirror. The right PMd which was activated during anatomic imitation might be involved in some difficulties associated with the imitation in which the subjects were required to carefully and internally coordinate the motor representation of the left and right hands. On the other hand, the left IFG might encode more complex and difficult goal compared with that in the specular imitation.

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