Measurement And Analysis Of Risk Factors Associated With Stress Fractures Of Lower Limbs

Objective:Lower extremity stress fracture is a common overuse injury to military recruits.With the aim of identifying the potential risk factors of this illness among recruits,this study can provide a new guidance for the prevention of this illness and a certain theoretical basis of targeted training programs in the future.Methods:This study used the prospective epidemiological survey.Questionnaires were used to record the variables such as basic information and lifestyle of recruits in the army from 2018 to 2019,and the gait parameters of the lower limbs of some recruits were collected by portable gait analyzer.During the military training of recruits,the orthopedist have followed up the whole training process and collected the basic information of the patients with stress fractures.They measured the recruit’s calcaneus bone density and bone metabolism markers after their training.Finally,through the comparison of the distribution of various indicators between the recruits in the stress fracture group and the recruits in the normal control group,this study explores the related risk factors of lower limb stress fractures.Results:1.Through comparative analysis of the questionnaire data,it was found that there were significant statistical differences of the recruits’physical training,subjective perception of training intensity,arch shape and active straight knee lift test between the two groups.The data about self-evaluation,birthplace and smoking situation of the two groups are correlated significantly in the univariate analysis,but not statistically significant in the logistic regression analysis.In addition,there was no significant difference in these datas between the two groups,including BMI,static ankle dorsiflexion distance,education level,psychological condition and consumption of carbonated beverages.2.There was no significant difference in related indicators of bone metabolism between the two groups.The calcaneus density Z-value of stress fracture group was(-0.383±0.903)g/cm~2,and the calcaneus density Z-value of normal control group was(0.247±0.897)g/cm~2.Through the independent sample test,it was found that the differences between the two Z-value were statistically significant(P=0.03).3.By analyzing the gait parameters of the two groups of recruits,it was found that these kinematic parameters,including the stride and foot swing speed of the lower limb of stress fracture group were higher than those of the normal control group.Study of the dynamic parameters showed a significant statistical difference of the foot-shooting speed and landing impact between the two groups.Besides,it was found that the distribution of gait cycle in different times does not affect the occurrence of stress fractures.Conclusion:1.The physical exercise,subjective perception of training intensity and arch structure of recruits and active straight knee lift test can be used as an warning indicators of risk factors for lower limb stress fractures.2.There is no significant correlation between bone metabolism markers and the occurrence of stress fractures in military recruits,and the calcaneus bone density of low level can be used as a risk factor for stress fractures.The calcaneus bone density examination can provide health guidance for the higher-risk groups such as athletes and cadets to prevent the occurrence of stress fractures of the lower limbs under permitting conditions.3.Abnormal gait patterns may affect the load on the lower limbs during exercise,with the changing of the normal stress,which can be used as a predictor of stress fractures of the lower limbs to a certain extent.However,since it was the first time to use prospective research method in this study to report the relationship between the occurrence of stress fractures in military recruits and their gait biomechanical factors,so the differences that were currently observed in these kinematic parameters still need to be confirmed by future studies.