Comparison of pelvic complex kinematics during normal locomotion in treadmill vs. overground walking

Abstract

Deviations from the normal movement pattern relates pathological gait. Conditions such as leg length inequality, increased lumbar lordosis and trunk bending relates to the abnormal kinematics of the pelvis. The assessment and rehabilitation of human locomotion is frequently assisted by a treadmill to simulate overground walking. Previous research suggest differences in temporal and angular kinematics when comparing treadmill to overground, questioning whether the treadmill replicates a similar setting as overground walking [1]. Similarly, treadmill running was commonly associated with increased anterior tilt when compared to overground. Furthermore, the investigations into the comparison of treadmill and overground running have produced conflicting results. Reported differences have been attributed to variations in surface, familiarisation, marker placement and identification protocol for toe off and heel strike [2, 3]. While, examining the effects of a lumbar corset on pelvic kinematics using a treadmill, a previous study indicated significant differences in rotations. However, no differences were reported in the sagittal and transverse planes [4]. Another investigation analysed the temporal differences of overground and treadmill walking and found at identical speeds, the stance period shortened by 6.7%, with increased cadence by 6.6% on the treadmill [5]. Similarly, Alton et al. [1] reported treadmill walking produced increases in cadence and decreases in stance time. Although, the treadmill has been described as advantageous in other comparative studies because of its convenience and the ease of control, the results reported in a previous study identified smaller ranges in the frontal and transverse anatomical plane for the pelvis whilst walking on the treadmill compared to overground. [4]. Furthermore, there are changes in variability and local stability for treadmill walking. In this context, another investigation concludes that treadmills may produce deceptive results [6]. When comparing overground and treadmill ambulation, the current study attempted to determine whether there are any reported or further differences in spatio temporal parameters of the pelvic complex and if these are related to gender differences.