University of Iowa Iowa Research Online Theses and Dissertations 2006 The effect of arch height on tri-planar foot kinemetics during gait Jason Mitchell Wilken University of Iowa Copyright 2006 Jason Mitchell Wilken This dissertation is available at Iowa Research Online: http://ir.uiowa.edu/etd/63 Recommended Citation Wilken, Jason Mitchell. "The effect of arch height on tri-planar foot kinemetics during gait." PhD (Doctor of Philosophy) thesis, University of Iowa, 2006. http://ir.uiowa.edu/etd/63. Follow this and additional works at:http://ir.uiowa.edu/etd Part of theRehabilitation and Therapy Commons THE EFFECT OF ARCH HEIGHT ON TRI-PLANAR FOOT KINEMATICS DURING GAIT by Jason Mitchell Wilken An Abstract Of a thesis submitted in partial fulfillment of the requirements for the Doctor of Philosophy degree in Physical Rehabilitation Science in the Graduate College of The University of Iowa May 2006 Thesis Supervisor: Associate Professor H. John Yack 1 ABSTRACT Deviations from normal foot structure are thought to result in hyper or hypo mobility preventing the foot from providing sufficient stability or mobility at appropriate times during the stance phase of gait. Such deviations in foot structure are often suggested as a risk factor for the development of common foot and ankle injuries. Though foot structure is believed to influence function its effect on foot motion and mechanisms thought to allow stability during the end of stance phase remain poorly understood. The purpose of this study was to determine the extent to which arch height affects foot kinematics during gait using a four segment foot model. Subjects included 17 healthy individuals with a wide range of arch heights and no past history of foot pathology. A three-dimensional motion tracking system was used to determine kinematics of the hallux, first metatarsal, forefoot, calcaneus and tibia during gait while subjects ambulated at a predetermined walking velocity of 0.78 statures/s. AP and lateral radiographs were used to determine coordinate system orientation for the first metatarsal, forefoot and calcaneus. The sagittal plane angle between the first metatarsal and calcaneus was used to represent foot structure No association was observed between foot structure, as represented by arch height, and foot kinematics as represented by excursion or coupling during the stance phase of gait. This surprising result provides no evidence to support the assertion that foot structure influences mobility during gait in individuals without foot pathology. The kinematic patterns observed were highly consistent between individuals and provide new insight into the mechanisms underlying the formation of a rigid lever for pushoff at the end of stance phase. Supination, consisting of forefoot and first metatarsal adduction and plantarflexion along with hindfoot inversion, was found to occur at approximately 76 percent stance. Kinematic coupling associated with activation of the 2 windlass mechanism is consistent with the concept of supination and occurs shortly after forward rotation of the first metatarsal and hallux dorsiflexion. In conclusion, deviation from normal foot structure appears to have little or no influence on foot mobility or intersegmental coupling due to activation of the windlass mechanism. Abstract Approved: ____________________________________ Thesis Supervisor ____________________________________ Title and Department ____________________________________ Date THE EFFECT OF ARCH HEIGHT ON TRI-PLANAR FOOT KINEMATICS DURING GAIT by Jason Mitchell Wilken A thesis submitted in partial fulfillment of the requirements for the Doctor of Philosophy degree in Physical Rehabilitation Science in the Graduate College of The University of Iowa May 2006 Thesis Supervisor: Associate Professor H. John Yack Copyright by JASON MITCHELL WILKEN 2006 All Rights Reserved Graduate College The University of Iowa Iowa City, Iowa CERTIFICATE OF APPROVAL _______________________ PH.D. THESIS _______________ This is to certify that the Ph.D. thesis of Jason Mitchell Wilken has been approved by the Examining Committee for the thesis requirement for the Doctor of Philosophy degree in Physical Rehabilitation Science at the May 2006 graduation. Thesis Committee: __________________________________ H. John Yack, Thesis Supervisor __________________________________ Thomas Cook __________________________________ Michel Ladouceur __________________________________ Russell Lenth __________________________________ Deborah Nawoczenski __________________________________ Charles Saltzman TABLE OF CONTENTS LIST OF TABLES.........................................................................................................iv LIST OF FIGURES........................................................................................................v CHAPTER I. INTRODUCTION....................................................................................1 Purpose.........................................................................................................7 Specific Aims...............................................................................................8 Hypothesis #1...............................................................................................8 Rationale for Hypothesis #1...................................................................8 Hypothesis #2...............................................................................................9 Rationale for Hypothesis #2...................................................................9 CHAPTER II. NEW INSIGHTS INTO ARCH FUNCTION DURING GAIT..............11 Introduction................................................................................................11 Methods.....................................................................................................13 Subjects...............................................................................................13 Procedure............................................................................................13 Definitions...........................................................................................14 Data Analysis......................................................................................15 Results........................................................................................................16 Arch Range of Motion.........................................................................16 First Metatarsal Lowering....................................................................16 First Metatarsal in Global Relative to Standing....................................16 Timing of First Metatarsal Motion.......................................................16 Discussion..................................................................................................17 Arch Motion........................................................................................17 Walking Velocity Independence..........................................................20 Summary.............................................................................................22 CHAPTER III. METHODS..........................................................................................33 Subjects......................................................................................................33 Radiographs ...............................................................................................33 Procedures..................................................................................................34 Lower Extremity Modeling.........................................................................35 Data Analysis.............................................................................................35 Limitations and Assumptions......................................................................37 CHAPTER IV. THE EFFECT OF ARCH HEIGHT ON FOOT MOTION DURING GAIT..........................................................................................42 Introduction................................................................................................42 Methods.....................................................................................................44 Subjects...............................................................................................44 Radiographs.........................................................................................44 Procedure............................................................................................44 Kinematics ..........................................................................................46 Results........................................................................................................46 ii Discussion..................................................................................................47 Subjects...............................................................................................48 Kinematics ..........................................................................................48 Role of Arch Height ............................................................................50 Conclusion.................................................................................................51 CHAPTER V. THE WINDLASS MECHANISM, SUPINATION AND THE EFFECT OF ARCH HEIGHT....................................................................58 Introduction................................................................................................58 Methods.....................................................................................................61 Subjects...............................................................................................61 Radiographs.........................................................................................61 Procedure............................................................................................61 Timing.................................................................................................63 Data Analysis......................................................................................63 Results........................................................................................................64 Discussion..................................................................................................65 Conclusion.................................................................................................72 Summary....................................................................................................72 CHAPTER VI. CONCLUSIONS.................................................................................85 REFERENCES.............................................................................................................89 iii LIST OF TABLES Table 2-1. Mean (± 1 SD) arch range of motion from heel strike to peak first metatarsal dorsiflexion (degrees).................................................................23 Table 2-2. Mean (± 1 SD) maximal lowering of first metatarsal relative to floor during mid-stance phase (degrees)..............................................................24 Table 2-3. Mean (± 1 SD) angular difference between 1MT angle during quiet standing and mid-stance (degrees)..............................................................25 Table 2-4. Mean (± 1SD) percent stance phase for initiation of nearly stationary first metatarsal............................................................................................26 Table 2-5. Mean (± 1SD) percent stance phase of initiation of forward (plantarflexion) first metatarsal rotation......................................................27 Table 3-1. Marker Placement.......................................................................................38 Table 3-2. Local Coordinate System definitions...........................................................39 Table 3-3. Definitions of gait events............................................................................40 Table 4-1. Mean (± 1 SD) range of motion (degrees) for kinematic patterns of interest as well as correlation coefficient values representing the association between radiographicially determine arch angle (degrees) and range and peak kinematic values. (CALC= Calcaneus, TIB= Leg, FORE= Forefoot, 1MT= First metatarsal, X= frontal plane motion, Y= transverse plane motion, Z= sagittal plane motion.)....................................52 Table 5-1. Mean and standard deviation values (percent stance phase) for the timing of first metatarsal and arch kinematic events. (FF= Forefoot contact, FR= Forward rotation of first metatarsal, PAE= Peak Arch Elongation, MINVEL= minima in first metatarsal forward rotation velocity.)....................................................................................................74 Table 5-2. Mean (± 1SD) values for both methods of calculating coupling ratios during the interval from PAE to MINVEL, the correlation between the two methods as well as the correlation between joint coupling as determined using linear regression and arch angle. Coupling ratio values greater than one indicate that transverse plane motion predominates. (CALC= Calcaneus, TIB= Leg, FORE= Forefoot, 1MT= First metatarsal; X= frontal plane rotation, Y= transverse plane motion, Z= sagittal plane motion.)..............................................................75 iv