Direct and indirect effects of alignment, range of motion, and gait measures on medial tibial stress syndrome status of runners

Context: Lower extremity alignment, range of motion (ROM), gait kinematics, and strength has been reported to be predisposed condition of Medial Tibial Stress Syndrome (MTSS). However, foot related measures were selectively assessed to examine the characteristics of MTSS. Moreover, previous studies examined only direct effect of potential risk factors on MTSS, however, there should be indirect effect of lower extremity alignment on MTSS by altering lower extremity gait biomechanics during running. Objectives: The purposes of this study are: 1) to investigate the characteristics of lower extremity static alignment, ROM, and strength, and gait kinematic measures among those with MTSS; and second, to identify the strongest factors that account for MTSS status in runners; 2) to investigate the direct and indirect effects of lower extremity alignment and gait kinematic measures on MTSS status, while relevant extrinsic factors are controlled, 3) to classify measures of static proximal and distal alignment and gait kinematics that are highly correlated to each other in order to develop latent variables (factors) that reduce the dimensionality of potential predictor measures. Design: A case control design. Setting: Laboratory Patients or other participant: A total of 74 recreational and competitive runners (37 normal, 37 MTSS injured) were recruited. Intervention: The independent variable was MTSS status. Main Outcome Measures: The dependent variables include 13 lower extremity alignment, 10 lower extremity (ROM), 7 strength, 20 maximum joint kinematics, and 10 total excursion measures during running (2.6m/s). All the measurements were performed three times by a single examiner who established intersession intra-tester reliability of at least ICC=.80 for each alignment measures. The difference between the MTSS and the control in all measures 111 was analyzed via independent T-test analysis. Those measures identified as being statistically significant (P