Abstract:

Objective Skin deformation refers to the range of skin change measured when key body parts are in motion, including the value of skin surface change rate and the difference between each movement change rates. Obtaining the rules of skin deformation of different parts, which is in the subdivision curved surface of the static and dynamic model of running lower limbs, is to solve the design requirements of the clothing pattern design of running tight functional clothing. A reference is provided for the running pants, and also for design and improvement of related pants pattern.

Methods A biomechanical simulation system was adopted to analyze the muscle fiber dynamics of the lower limb muscles during periodic running, and a hand-held 3-D scanner was adopted to scan the skin of the lower limb for selected key frame movements. After analyzing the difference of skin deformation data and comparing with the static and dynamic human model subdivision surface, a more scientific and perfect scheme for acquiring the whole skin deformation was obtained.

Results The biomechanical simulation system was adopeed to analyze the muscle fiber active force of human lower limb muscles during periodic running (Tab.1). According to the systematic sampling method, 61 samples of muscle initiative data in one running cycle were selected and processed, and the muscle fiber initiative curve was obtain (Fig.1). The muscle with obvious mean of muscle fiber active force was selected, and the action corresponding to the time frame of its peak value was taken as the key frame action (Fig.2). The hand-held 3-D scanner was adopeed to scan the skin of the lower limbs in key frame movements. The skin deformation of the left and right sides of the body was taken into account to analyze the differences of the skin deformation data of the lower limbs in different movements. The transverse change rate of skin surface deformation was analyzed (Fig.4), and the longitudinal change rate of skin surface deformation was analyzed (Fig.5). Meanwhile, the dynamic and static subdivision surfaces of the human model were compared, and it was found that the changes of the body back from the hip circumference to the middle leg circumference area and the body front from the hip circumference to the thigh circumference area are the largest, and the changes of the area around the knee joint are the largest, too. The other areas show no significant changes (Fig.6).

Conclusion The dynamic and static human models are expanded and compared, which enables quick and effective observations of skin deformation of various parts of the human body. This method can be applied for multiple purposes. The rule of skin deformation in static and dynamic model subdivision surface contrast map is consistent with that of skin deformation calculated after measuring the area or length. At the same time, the rules of skin deformation obtained by the two methods can be verified with each other, which make the scheme of acquiring the whole skin deformation more scientific and perfect.

Key words: running motion, biomechanical simulation, active fiber-force, skin deformation, subdivision surface of model, sports garment