INVESTIGATION OF THE LOWER EXTREMITY STATIC POSTURES PREDICTING VALGUS COLLAPSE DURING DROP LANDING IN KOREAN MALE AND FEMALE – LOGICAL ANALYSIS OF DATA (LAD) APPROACH

Background The result of 2002∼2012 National Health Insurance Sharing Service (NHISS) data analysis demonstrated that the gender9s odds ratio of ACL was as low as 1.06, which is different from other studies. The static posture measures (SPM) of Asian may not be strongly associated with valgus collapse during landing. Objective To investigate SPMs that account for valgus collapse in Korean male and female using the LAD approach. Design Cross-sectional study. Setting Controlled laboratory. Patients (or Participants) Forty-four active male (age: 22.2±3.6 yrs; Height: 176±6.6 cm; Weight: 73.3±9.7 kg) and 43 female (age: 21.9±2.5 yrs; Height: 163±5.3 cm; Weight: 56.5±5.1 kg) with no history of lower extremity injury were recruited. Interventions (or Assessment of Risk Factors) Gender. Main Outcome Measurements Joint kinematics associated with valgus collapse during drop landing were extracted (Vicon Inc, Oxford, UK) during drop landing task. Thirteen lower extremity SPMs were collected. LAD was implemented using the machine learning software, Weka 3.7.10 (U of Waikato, Hamilton, New Zealand) to generate male and female patterns that characterize features of SPM and its association with valgus collapse. Results A total of eight and 33 distinct male and female patterns respectively could be generated (>10% relative prevalence (RP)). Interestingly, Joint kinematics associated with valgus collapse were not shown in patterns, but only six SPMs were included. The most relevant pattern that represents male (RP 25.00%) was tibiofemoral angle less than or equal to 9.5° and leg length discrepancy greater than −3.5 cm. The most relevant pattern that represents female (RP 34.88%) was Q-angle greater than 17.5°, genu recurvatum greater than −1.5°, femoral anteversion greater than 5.5°, and leg length discrepancy less than or equal to 2.5 cm. Conclusions SPMs of Korean male and female were not associated with valgus collapse during drop jump. It seemed that the Korean female demonstrated similar neuromuscular control characteristics as male to avoid valgus collapse.