Development of a Posture Alert Device for the Postural Optimisation of the Human Upper Limb

Abstract

The human musculoskeletal system consists of the skeletal framework made up of bones. The muscles, tendons and ligaments bind and hold the bones in position and allow them to move. The joints of the human body possess limitations associated with their degrees of freedom. Once the appendages try to move outside these limits, they give way to various musculoskeletal problems, such as shoulder pain, pain in the elbow, back, limbs, waist and so on. Such problems appear gradually if the person assumes incorrect postures for a prolonged duration. To tackle problems associated with incorrect postures, certain training devices, braces and alarm systems are used to remind and prompt the person, to correct his posture. Most of the posture alert systems are associated with improper spinal column orientation.This project involves developing a Posture Training Device for the upper limbs of a human for minimizing the risks of musculoskeletal problems associated with the elbow joint. The device consists of two major modules viz. an angular calibration unit and an auditory alarm unit. The angular calibration unit is designed with focus on simplicity of its construction and ease of use by the subject. The functional part of this unit is a simple electrical make and break circuit. The auditory alarm unit consists of the alarm properly shielded from the human skin to prevent damage to the device. The casing is designed based on the principles of Strength of Materials. The entire set-up is attached to a cuff made of flexible fabric to be worn on the arm. Anthropometric dimensions were considered to determine the dimensions and quantity of fabric required. The virtual three dimensional model of the assembly is generated and the dimensions are fixed with the use of Digital Human Modeling in the CAD environment. The physical prototype is developed using the actual materials required for the product. The main focus is on simplicity of technology for its manufacture and use on a mass scale