KINEMATICS AND ELECTROMYOGRAPHY OF LOWER-LIMB MUSCLES IN OVERGROUND AND TREADMILL RUNNING

Treadmills are often used in research to analyse kinematic and physiol ogical variables. The success of transfering the results to overground running depends on the comparability of the values between the two si tuations. The aim of the present study was to compare the kinematics a nd muscle activities in overground and treadmill running. Ten male phy sical education students with experience in treadmill running were ask ed to run with a speed of 4.0 and 6.0 mis both overground and on a Woo dway treadmill. The 3D-kinematics of the limbs were studied using a tw o camera video tracking system. Additionally the surface EMC of six lo wer limb muscles and the pattern of ground contact of the right foot w as registered. Both the activities of the leg muscles and several kine matic Variables showed systematic changes from overground to treadmill running. On the treadmill the subjects favoured a type of running tha t provided them with a higher level of security. The swing amplitude o f the leg, the vertical displacement and the variance in vertical and horizontal velocity were lower in treadmill running. The angle between shoe sole and ground at foot impact was also lower and the forward le an of the upper body was higher in Funning on the treadmill compared w ith the overground mode. Most of the subjects reduced their step lengt h and increased stride frequency in treadmill running. Furthermore, th e contact time in treadmill running was shorter than for overground ru nning. The above mentioned kinematic variables were significantly diff erent (p<0.05). The EMG patterns of the leg muscles were generally sim ilar between overground and treadmill modes, but some minor difference s could consistently be identified.