The Effects of Various Methods of Infant Carrying on the Human Body and Locomotion
Date
2009-05
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Publisher
University of Delaware
Abstract
Although the causes of the evolution of bipedalism are unclear, one consequence is that the hands are freed from use in locomotion, making it possible to carry objects including tools, firewood, water, food, and dependent, helpless offspring. Carrying infants can be problematic because while the baby needs to nurse, the mother also needs to be able to work. Cross-culturally, there are many different methods and tools used by women to carry their babies throughout the day such as front wraps, back wraps, side slings, and carrying in-arms. In this study, I conducted motion analysis on 22 women carrying 7 and 20 lb weights using these four ways of carrying infants. In the biomechanical engineering lab, I observed women carrying two different loads while walking and standing, to look at the change in their posture and variation in gait. Approved by the Human Subjects Board at the University of Delaware, the protocol does not involve harmful or invasive procedures, and assures anonymity. The two main objectives of this research were to understand the effects of baby weight and baby carrying position on the hip flexion and extension angles and the lateral trunk and forward trunk angles. The results show that on the whole, carrying an increased weight exaggerates the effect of the load on the hip and trunk angles. Also, the front and back carrying positions cause a change in the gait of the carrier, while the back wrap and in arms carrying position cause a change in the posture of the carrier. This study will lead to a better understanding of a universal cultural practice that affects the biology of the human body.