Evaluating the coupling between foot pronation and tibial internal rotation continuously using vector coding.
Excessive pronation, because of its coupling with tibial internal rotation (TIR), has been implicated as a risk factor in the development of anterior knee pain (AKP). Traditionally, this coupling has been expressed as a ratio between the eversion range of motion and the TIR range of motion (Ev/TIR) that occurs during stance. Currently, this technique has not been used to evaluate specific injuries or the effects of sex. In addition, Ev/TIR is incapable of detecting coupling changes that occur throughout stance. Therefore, the purpose of this study was to compare the coupling between eversion and TIR in runners with (n = 19) and without AKP (n = 17) and across sex using the Ev/TIR ratio, and more continuously using vector coding. When using vector coding, significant coupling differences were noted in runners with AKP (34% to 38% stance), with runners with AKP showing relatively more TIR than eversion. Similarly significant differences were noted across sex (14%-25% and 36%-47% stance), with males transitioning from a loading to propulsive coordination pattern using a proximal to distal strategy, and female runners using a distal to proximal strategy. These differences were only detected when evaluating this coupling relationship using a continuous technique such as vector coding.
Sports Research Laboratory, New Balance, Boston, MA, and the Biomechanics Laboratory, University of Massachusetts, Amherst, MA.
Pedro
P
Rodrigues
Ryan
R
Chang
Trampas
T
TenBroek
Richard
R
van Emmerik
Joseph
J
Hamill
D000328:Adult; D000465:Algorithms; D000843:Ankle Joint / Q000502:physiology*; D003198:Computer Simulation; D005260:Female; D005528:Foot / Q000502:physiology*; D006801:Humans; D016247:Information Storage and Retrieval / Q000379:methods; D008297:Male; D008954:Models, Biological; D016059:Range of Motion, Articular / Q000502:physiology*; D012399:Rotation; D012420:Running / Q000502:physiology*; D012727:Sex Characteristics; D013977:Tibia / Q000502:physiology*