Research On Functional Movement Tests As Screening Tools To Identify Male Football Players At Non-contact Lower Limb Injury Risk

Objective: Through the functional movement tests and injury screening for male college football players,work out scientific and accurate assessment standard of injury risk and provide prevention advice for football sports injury prevention program.Methods: Baseline testing for total of 149 male college football players in Beijing of the YBT-LQ Test,SLS Test,LESS Test.Participants were followed prospectively throughout one year for diagnosis of non-contact lower limb injuries.We used receiver operator characteristic curves to determine a cut-point on the three tests.Results:(1)Non-contact lower limb injuries of male college football players in Beijing were all soft tissue injuries,among which ligament injuries were the most common type,and knee joints were the most vulnerable part.(2)In YBT-LQ,the posterior-medial(PM)reach distance asymmetry,the PM normalized reach distance asymmetry and the composite score(CS)asymmetry were significantly different between those injured and not injured(P<0.05).No significant differences in other indexes between the two groups(P>0.05).No significant difference in SLS score between the two groups(P>0.05).The LESS score was significantly different between the two groups(P<0.01).There were no significant difference in the sagittal and coronal total score between the two groups(P>0.05).(3)The ratio of knee valgus(63.08%)and trunk internal rotation(50.47%)in the SLS test was higher than 50%.The prevalence of non-contact lower limb injuries in those showed hip lift and knee valgus were higher than those not showed in SLS test,and these two wrong movements proportions in those injured were higher than not injured(P>0.05).(4)In LESS test,the ratio of five movements on the sagittal plane were more than 50%,respectively were: the sagittal joint displacement is average or stiff(95.97%),the second floor hip flexion Angle is less than the first(93.33%),the trunk does not flex more between initial contact and maximum knee flexion(86.58%),the knee flexes less than 45 degrees between initial contact and maximum knee flexion(73.15%),the ankle plantar flexion at initial contact(51.01%).The prevalence of non-contact lower limb injuries in those respectively showed seven movements were higher than those not showed,and the wrong movements proportion in those injured was higher than not injured(P>0.05).Seven movements were trunk flexion at initial contact,the ankle plantar flexion at initial contact,the knee flexes less than 45 degrees between initial contact and maximum knee flexion,the trunk does not flex more between initial contact and maximum knee flexion,the second floor hip flexion Angle is less than the first,the sagittal joint displacement is average or stiff.In LESS test,the ratio of three movements on the coronal plane were more than 50%,respectively were: the center of the patella is medial to the midfoot at initial contact(68.46%),the foot is externally rotated more than 30 degrees between initial contact and maximum knee flexion(57.05%),the feet are positioned greater than shoulder width apart at initial contact(55.70%).The prevalence of non-contact lower limb injuries of in those respectively showed two movements were higher than those not showed,and the wrong movements proportion in those injured were higher than not injured(P>0.05).The movements were asymmetric initial foot contact at initial contact and the foot is externally rotated more than 30 degrees between initial contact and maximum knee flexion.(7)The ROC analysis identified a PM reach distance asymmetry cut-point of2.25 cm as having optimal screening properties: 1 sensitivity,0.444 specificity,+LR1.799,-LR0.000.The AUC was 0.759(P<0.05),OR was 1.216,RR was 10.112,posterior probability was 17.79%.(8)The ROC analysis identified a PM normalized reach distance asymmetry cut-point of 2.71% as having optimal screening properties:1 sensitivity,0.481 specificity,+LR1.927,-LR0.000.The AUC was 0.759(P<0.05),OR was 1.232,RR was 11.607,posterior probability was 18.82%.(9)The ROC analysis identified a CS asymmetry cut-point of 6.50% as having optimal screening properties: 0.500 sensitivity,0.910 specificity,+LR5.556,-LR0.549.The AUC was0.725(P<0.05),OR was 10.083,RR was 6.45,posterior probability was 40.06%.(10)The ROC analysis identified a LESS cut-point of 8.5 as having optimal screening properties: 0.875 sensitivity and 0.617 specificity,+LR2.285,-LR0.203.The AUC was 0.768(P<0.01),OR was 11.255,RR was 11.255,posterior probability was21.56%.Conclusions:(1)Male college football players in Beijing showed dynamic knee valgus,decreased sagittal flexibility and bilateral lower limb function asymmetry in functional movement tests.The injury group performed worse.(2)In YBT-LQ,the PM reach distance asymmetry ≥2.25 cm,the PM normalized reach distance asymmetry ≥2.71%,the CS asymmetry ≥6.50%,and the LESS≥ 8.5 can be used as the evaluation criteria for the non-contact lower limb injury risk of male college football players in Beijing.The total score of SLS can not be used as a evaluation criteria for the non-contact lower limb injury risk of male college football players in Beijing.