Measurement of Undetectable Walking Feature by Appearance Based on Plantar Skin Deformation

Abstract

Walk is fundamental motion in daily life. Everyday life isn’t without walk. However, walk always involves risk of falling. This study was focused on a plantar skin deformation which was undetectable part by appearance during a walk. This research investigated the plantar skin deformation and variability in elder and young. The changes of plantar skin contact area, slipped contact area and non-slipped contact area were measured and compared during the stance phase. A total of 30 (10 normal young males (22±2 years) and 20 normal elders (73±5 years)) human subjects were recruited in this research. Subjects ware asked throughout the experiment to walk at a comfortable speed on a walkway four times per one trial. Feature points of plantar skin were calculated by using Harris corner image processing method. Changes of plantar skin contact area were calculated by using binarization images. As results, the changes of plantar skin contact area in the elder were significantly higher than the young group during Initial grounding (p<0.05). The standard deviation of the changes of plantar skin contact area in elder group were significantly higher than in young group during initial grounding and previous phase (p<0.05). The results suggested that the elder have more risk of falling than young during initial grounding and previous phase (p<0.05). The changes amount of plantar skin slipped area in the elder group were significantly higher than the young group during the plantar skin contact (p<0.05). This phenomenon suggested that the elder group tend to slide feet during the stance phase. In conclusion, the plantar skin deformation measurement can potential to calculate of undetectable walking feature by appearance and screen people who have potential risk of falling.KeywordsFeature pointPlantar skin deformationWalking featureImage measurement