A comparison of overground and treadmill running for measuring the three-dimensional kinematics of the lumbo-pelvic-hip complex

Objective. To compare overground and treadmill running for differences in t he three-dimensional angular kinematics of the lumbo-pelvic-hip complex. Design. A within-subject repeated measures design. Back-ground. The treadmill is an attractive research instrument as speed an d slope are easily controlled and the required calibration volume is reduce d. However, the degree to which treadmill running simulates overground runn ing has not been resolved in the literature to date. Methods. 10 able-bodied subjects ran overground and on a treadmill at a sel f-selected speed. The treadmill speed was matched to each subjects respecti ve average overground speed. The time-distance and the three-dimensional an gular kinematic data were captured using a passive marker based motion anal ysis system. A set of angular and temporal kinematic parameters were extrac ted from the data and subjected to statistical analyses. Results. Significant differences were found between overground and treadmil l running for all the time-distance parameters. Despite this, the kinematic s of the lumbar spine and pelvis were similar between the two running condi tions, with only three parameters being significantly different. These were lumbar extension at initial contact, anterior pelvic tilt at initial conta ct and the first maximum anterior pelvic tilt. Hip flexion-extension parame ters were also only found to display subtle differences. Of the 17 hip para meters analysed, only hip flexion at initial contact, maximum hip flexion a t loading response, hip extension at toe off, maximum hip extension and hip flexion-extension range of motion were found to be significantly different . Conclusion. A high powered treadmill with a minimal belt speed fluctuation is capable of being used to obtain a representation of the typical three-di mensional kinematic pattern of the lumbo-pelvic-hip complex during running.