Impact Force on Human Body Resulted from Safety Harness during Slip-Related Falls in Gait

Real slip and fall reproduction in a lab environment is important to investigate the mechanisms behind slip-related falls as well to produce perturbation training for the reduction of future falls. To prevent an actual fall and any potential injuries to the subjects, a safety harness in combination with shock absorber ropes is essential during these experiments. Although a safety harness prevent the subjects from falling down on the ground, the faller does still take an impact when the harness deploys during falling. Sometimes this impact force could cause serious trauma to the affected area. For example, during a vertical fall, the impact force between the straps from the hips down to the crotch could be high; thus it can injury the tissues in the affected area. Further, the resulted impact force between body segments, such as at neck or between vertebras could lead to injuries at spinal cord too. The purpose of this study was: (1) to examine the impact force between body segments resulted from safety harness during falling by computer simulation assisted by dynamic optimization; and (2) to analyze the possibility of injuries to human body bone, tissue, or ligament due to the impact force among healthy older adults. Analyzing the results, a general trend was observed which indicated relatively higher impact forces in the thoracic-lumbar region as compared to neck or cervical spine region. Results also showed that the impact force would not cause any injury to either bone or soft tissue. However, for couple of subjects relatively higher forces were noted in the lower back or thoracic-lumbar region