Measurement of hand-transmitted vibration of tapping the long cane for visually handicapped people in Japan.

Abstract

The long cane can be used as a mobility aid for visually handicapped people. According to a questionnaire completed by Japanese cane users, it seems they are not always satisfied with using long canes for a variety of reasons. In this study, hand-transmitted vibration from the long cane due to tapping the ground was measured because an exposure to repeated shock-type tapping vibration may affect the hand-arm system. A sighted female wearing a blindfold participated. The measurement was carried out in different conditions with three different ground materials both indoor and outdoors. The vibration at three axes of the cane grip and one axis at the wrist were measured. The pinch forces between an index finger and the grip were also measured using a strain gauge in order to observe how the vibration characteristics depend on the changing forces. Measurement, evaluation and assessment were based on the International Standard (ISO 5349). The estimated daily exposure time and the transmissibility were obtained in order to investigate the severity of the hand-transmitted vibration caused by the long cane. It was found that the characteristics of tapping vibration depend on different measurement conditions and the vibration might be associated with a health risk over a long life span.