Kinematical Analysis of Adult Crawling with Different Heights of Gravity Center

Human, other primates and non-primate quadrupeds share common kinematic characteristics of limb coordination, which has been proven that they have a similar central pattern generators (CPGs) . Objective:Based on previous studies, we found and compared the kinematic characteristics of the movement among crawling human, erectly walking human and moving quadrupeds by studying handand-foot crawling of 8 healthy male adults with different heights of gravity center (~0.65 m, ⁰.55 m and ⁰.45 m, respectively) . Methods:In this study, kinematic data of limbs and torso were synchronously collected from 8 healthy adult subjects through a three-dimensional dynamic capture devices equipped with 8 IR capture lenses. All subjects were involved in a 9-weeks reptile study and testing (every 3 weeks to learn and test a crawling method) . All tests were performed after the subjects were familiar with the crawl, and the data were collected for upright walking after three kinds of crawling tests. The selected kinematic parameters mainly include ipsilateral phase lag and range of joint motion.Resultsand Conclusion:Compared to other studies, this research crawling slower;the subjects showed a larger range of kinematic coordination modes (diagonal pattern and lateral sequence pattern) and a greater range of motion of the major joints, compared with the typical kinematic characteristics of upright walking, And the shoulder joint and elbow joint activities gradually decreases, the hip, knee and ankle motion range increased gradually with the crawling center of gravity height reduced. It showed that in a certain range, the higher the center of gravity, the smaller the bearing surface, poor stability, which need more limb support stability. The body center of gravity is lower, the more you have to the stability of the shoulder, elbow, and the flexibility of the hip, knee and ankle; on the contrary, body will need to shoulder, elbow joint flexibility and stability of the hip, knee, ankle.