|（School of Physical Education，South China Normal University，Guangzhou 510006，China)
Abstract: The authors studied the biomechanical characteristics and affecting factors of undesirable gaits of univer-sity students, so as to provide a theoretical basis for revealing the gait characteristics of university students on cam-pus, for probing into the biomechanical factors and mechanism of toe-in gait formation, and for researches in rela-tion to preventing and treating toe-in gait and other undesirable gaits. The results show the followings: 1) university students’ step angle is (7.5±8.4)°, their toe-in gait occurrence rate is 28%, their toe-out gait occurrence rate is 27%; the gender differences of gait characteristics are very significant, mainly showing in step angle mean value, toe-in and toe-out gait occurrence rates, as well as left and right asymmetry percentage; 2) at landing, normal gait’s plantar pressure center trace velocity is the highest, the toe-in gait’s is the lowest, the toe-out gait’s is somewhere in be-tween; at the supporting stage, normal gait’s pressure center trace velocity is balanced, the peak appears at the 50% position of the foot supporting stage, toe-in gait’s and toe-out gait’s plantar pressure center trace velocity peaks are higher, appearing at the 65% position of the foot supporting stage; 3) toe-in gait’s angle joint intortor strength and extortor strength are weaker than normal gait’s, its ratio of intortor strength to extortor strength is higher than nor-mal gait’s; toe-out gait’s ratio of intortor strength to extortor strength is significantly lower than normal gait’s; 4) at the angular speeds of 30°/s and 120°/s, the ratio of intorsion mean moment to extorsion mean moment is weakly negatively correlative with step angle, and significantly; 5) toe-in and toe-out gaits’ FMS scores (14.5 and 13.4) are significantly lower than normal gait’s (16.9); 6) toe-in gait’s dynamic balance stability is poorer than normal gait’s, and very significantly; toe-out gait’s dynamic balance stability is close to normal gait’s. This research shows the followings: 1) the gender differences of gaits of university students are very significant; coupled with children toe-in gait research results derived earlier, it is concluded that when not intervened, toe-in gait will not naturally disappear as the body develops; 2) the plantar pressure center distribution of toe-in gait of university students is irrational, the pressure tends to move backward as compared with normal gait’s, toe-in gait is unable to effectively utilize foot arch’s buffer function, the heel suffers greater pressure at landing, the supporting point was unable to move to the hallux to achieve an ideal ground hitting effect at lifting; there is no significant difference between toe-out gait and normal gait in terms of plantar pressure center distribution; 3) toe-in gait of university students is caused by multiple biomechanical factors, which include various weak links existing in the body movement chain, poor proprioception, weak lower limb muscle strength, poor lower limb joint extorsion flexibility etc; 4) toe-out gait’s formation reason is not simply opposite to toe-in gait’s, provided with its own unique biomechanical mechanism, needed to be further probed into by more researches.
Key words: sports biomechanics；step angle；plantar pressure center isokinetic muscle strength；functional movement screening；university student