Dynamic ease allowance in arm raising of functional garment

Abstract

The functional garments are important protective device for the disciplinary forces, such as police, fireman and soldier. Typical protective garments are made of special non-stretchable fabric and hence can restrict the movement of the wearer if the garment is not designed properly. A protective garment that can ensure maximal range-of-motion can be a difference of life and death when the disciplinary force is on duty. There are many aspects of range-of-motion. In the current study, we address the question of the appropriate amount of dynamic ease allowance (movement ease) required for any given height that the arm is supposed to reach. The relationship among the dynamic ease allowance, under arm sleeve length, and side seam length was derived, by using the rod joint model of the human being and assuming the motion is a cross-sectional one along the frontal plane. Sixty subjects wore the special net garment to record the reference of zero dynamic ease allowance, and then the adjustable garments of different scye depth, which is related to the dynamic ease allowance. The subjects were asked to move their arm along a vertical plane, from rest position to the maximum height that they can reach. Such motions were recorded by a motion capturing system. The experimental data was compared to the theoretical prediction. Since the analysis was conducted using the 3-D data and the garment measurements must be converted from the 3-D environment (when the garment is worn) to the 2-D environment (when the garment is not worn). The conversion approximation is also presented. Consequently, when the required posture is known, the required scye depth and the required dynamic seam allowance can be found. The armhole can be designed accordingly.