%0 Journal Article
%T Changes in joint coupling and variability during walking following tibialis posterior muscle fatigue
%A Reed Ferber
%A Michael B Pohl
%J Journal of Foot and Ankle Research
%D 2011
%I BioMed Central
%R 10.1186/1757-1146-4-6
%X Twenty-nine participants underwent an exercise fatigue protocol aimed at reducing the force output of tibialis posterior. An eight camera motion analysis system was used to evaluate 3 D shank and foot joint coupling and coupling variability during treadmill walking both pre- and post-fatigue.The fatigue protocol was successful in reducing the maximal isometric force by over 30% and a concomitant increase in coupling motion of the shank in the transverse plane and forefoot in the sagittal and transverse planes relative to frontal plane motion of the rearfoot. In addition, an increase in joint coupling variability was measured between the shank and rearfoot and between the rearfoot and forefoot during the fatigue condition.The reduced function of the tibialis posterior muscle following fatigue resulted in a disruption in typical shank and foot joint coupling patterns and an increased variability in joint coupling. These results could help explain tibialis posterior injury aetiology.Although runners often sustain acute injuries such as ankle sprains and muscle strains, a vast majority of running injuries could be classified as cumulative micro-trauma (overuse) injuries [1-4]. The aetiology of an overuse running injury is multifactorial but muscle fatigue and/or weakness has been discussed as a primary contributing factor [5-9]. Indeed, many lower extremity overuse injuries have been attributed to atypical foot mechanics during gait [10-13]. The tibialis posterior is believed to play a key role in controlling rearfoot eversion [14,15] and providing dynamic support across the midfoot and forefoot during the stance phase of gait [15-17].The proximal origin of tibialis posterior lies on the interosseous membrane and posterior surfaces of the tibia and fibula. The muscle has multiple distal insertions including the navicular tubercle, the plantar surface of the cuneiforms and cuboid, and bases of the second, third and fourth metatarsals [18]. Biomechanical research conducte
%U http://www.jfootankleres.com/content/4/1/6