What is the influence of cambered running surface on lower extremity muscle activity?

Running on a road for fitness, sport, or recreation poses unique challenges to the runner, one of which is the camber of the surface. Few studies have examined the effects of camber on running, namely, kinematic studies of the knee and ankle. There is currently no information available regarding muscle response to running on a cambered road surface. The purpose of this study was to investigate the effects of a cambered road on lower extremity muscle activity, as measured by electromyography in recreational runners. In addition, this study examined a true outdoor road surface, as opposed to a treadmill surface. The mean muscle activity of the tibialis anterior, lateral gastrocnemius, vastus medialis oblique, biceps femoris, and gluteus medius were studied. Fifteen runners completed multiple running trials on cambered and level surfaces. During the stance phase, mean activities of tibialis anterior, lateral gastrocnemius, and vastus medialis oblique were greater on the gutter side than the crown side. There were no differences in mean muscle activity during the swing phase. The findings of this study suggest that running on a road camber alters the activity of select lower extremity muscles possibly in response to lower extremity compensations to the cambered condition.