Significance of the body-weight's ratio of caregiver and receiver in the training process of care-giving motion

摘要

One-to-one is the most common laboratory training method in care-giving motion. In this paper, the significant effect of the body-weight's ratio of the training pair, caregiver and receiver, was investigated. The motions of caregiver and receiver for ten times' trials of the care-giving motion performed by beginners were quantitatively and simultaneously captured by a 3D motion analysis system and the relationship was analyzed between the change of the skill level and other factors including the body-weight's ratio of the training pair. The performance was evaluated with following characteristics; center of gravity (COG) of caregiver and the receiver, the operating time, the total length of the trajectory of COG in caregiver and receiver (respectively), the distance between caregiver and receiver and the range of the movement of caregiver's knee joint at every trial. A principal component analysis was applied to these characteristics to extract the factors effectively explaining the learning process of care-giving motion. As a result, two components constituting the care-giving skill were extracted, (1) a component representing the degree of skill of the movements, (2) a component denoting the ability of the caregiver to reduce body stress. The first component's scores were increased in the almost subjects along with the trial. On the other hand, there found many trainees whose second component's scores were decreased. The most significant factor affecting second component's score was the weight ratio of caregiver and receiver. These results suggested the significance of the weight ratio of the pair, namely, if the care-receiver was too small for the caregiver, the caregiver seemed to use only own arm's muscle and would tend to stop using body mechanism. It seemed reasonable to think that they are likely to sustain damage to their muscles and bones, if they use the same position to care for heavier receivers.