Comparison of kinematics and kinetics symmetry of lower limbs during running

Introduction: Symmetry and asymmetry of the limbs’ movement pattern during running is introduced as one of the main critical challenges of human locomotion. The aim of this study was to investigate kinematics and kinetics symmetry of lower limbs during running at a constant speed. Martials and Methods: The present study was conducted as a quasi-experimental study. Elite runner (age: 34.75±6.63 years) participated in this study. Running at constant speed was conducted by each subject at 2/5 m.s^-1 on treadmill while kinematic (Raptor-4 motion analysis) and kinetic data (Force plate, Bertec) were captured at 150 Hz and 300 Hz, respectively. The internal joint moments in sagittal plane were represented in the joint-coordinate system and were calculated using a standard inverse-dynamics approach and were normalized by the subject’s body mass as well as running cycle over 101 time points. The normality and homogeneity of variances assumptions of the dependent variables was tested using Bartlett and Leven’s test. Independent t-tests were conducted to examine the symmetry of hip, knee and ankle moments between dominant and non-dominant joints during stance phase of running (P 0.05). Results: Results of the present study showed no significant difference exists between dominant and non-dominant lower joints regarding the peak moments of hip, knee and ankle in sagittal plane during stance phase (P 0.05) as well as between peak flexion angle of dominant and non-dominant hip, knee and ankle joints during running. Conclusion: Symmetry exists in lower joints sagittal moments and flexion angle during running at the constant speed. According to the results dominant and non- dominant lower joints play propulsive and absorbent roles cooperatively.