Influence of carrying system on human gait and fatigue

Objective To investigate the influence of different variable combinations of the carrying system on gait and muscle fatigue during weight-bearing walking on both shoulders and back, and to optimize daily carrying experience. Methods From September to December, 2018, 6 male college students were selected as subjects; the electromyographic signal of the anterior tibial muscle and plantar pressure were measured during weight-bearing walking under six different variable combinations of the carrying system (with the three variables of gravity center, single or double shoulders, and waist cushion), and a subjective evaluation test was performed for the degree of fatigue. The electromyographic data and plantar pressure data were processed and compared to evaluate behavior and fatigue. Results Different variable combinations of the carrying system had significant influence on the degree of fatigue and gait (P<0.05). Both subjective and objective analyses found that the carrying system with different heights of gravity center and single-or double-shoulder carrying mode had great influence on human fatigue and walking gait, while the hardness of waist cushion had little influence. Compared with the other groups, the group with a high gravity center, a double-shoulder carrying mode, and a soft waist cushion had a significantly smaller slope of average electromyographic amplitude, a significantly larger slope of median frequency, and a significantly lower degree of plantar pressure curve disorder. Conclusion The carrying system with a relatively high gravity center, a double-shoulder carrying mode, and a soft waist cushion can significantly relieve fatigue, with low influence on walking gait. Key words: Gait; Fatigue; Plantar pressure; Surface electromyography; Carrying system