AN EXAMINATION OF INTRAROWER COORDINATION MOVEMENT COUPLING USING CONTINIOUS RELATIVE PHASE

The purpose of this study was to identify the coupling relationships between body segments joint angles created in completion of the rowing stroke. A dynamical systems approach utilising continuous relative phase was used to investigate the higher order dynamics of the movement. Five rowers (1 experienced, 4 novice) completed a 2000m row on a RowPerfect ergometer; the kinematics of which were captured using a 200Hz motion analysis system. The results indicate that purely upper limb, and one joint upper- one joint lower limb coupling, show much larger variation than purely lower limb coupling. In particular the knee-elbow coupling relationship differs dramatically between the experienced rower and novices. From a practical viewpoint this coupling relationship should be focused upon to improve the rowing ability of the novice. The purpose of this study was to investigate the intrarower coordination during the performance of a 2000m row. Whilst the analysis of interrower coordination between a rowing crew have been carried out (e.g. Hill, 2002), this has not occurred in the case of intrarower coordination. Further, the analysis of rowing technique has focused predominately upon kinetic data (e.g. force curve produced) without examining the kinematic movement characteristics. The objective then is to examine the kinematic data with a view to differentiating between an elite and novice rowers. The identification of the key components of the rowing stroke will allow these components to be used for feedback to the rower in order to improve rowing technique. Rowing can be considered to be an open motor skill which is cyclical in nature. From this perspective it can be compared to the motor skill of walking, or the production of a natural gait pattern. The literature is abundant with evidence of the relevant coordination within gait (e.g. Haddad et al., 2006), but not within rowing. This paper aims to apply this type of analysis to rowing data. The use of dynamical systems theory (DST) is ever increasing within the analysis of biomechanical and human movement data. It has been reported that the rich dynamical interactions amongst the multiple degrees of freedom during movement may not be adequatly represented using simple parameter - time plots (Hamill, 2006). Consequently, movement coordination and variability has received increasing attention in recent years. Movement coupling, the extent to which two segments are functionally linked during movement (Kurz & Stergiou, 2004), allows the behaviour of two segments to be described by one variable. Relative motion plots such as angle-angle diagrams and phase plane plots provide information about the movement of a segment relative to another segment or relative to angular velocity (Kurz & Stergiou, 2004). However, this data is limited to qualitative interpretation. Further calculations using a technique such as continuous relative phase (CRP) is necessary to determine quantitatively the extent to which two segments are coordinated. Therefore, while the basic kinetics and kinematics of a movement pattern may not change the higher order parameters contain much more information (Hamill, 2006). The optimisation of the rowing stroke is something that athletes, coaches and sport scientists strive for. Despite the physiological demands of rowing, it is rowing technique (or biomechanics) that can determine the more successful rower from others of similar physiological calibre (Nelson & Widule, 1994). Despite relatively numerious studies the biomechanics of rowing remains poorly understood, although it has previously been reported that certain elements of the rowing stroke must be produced in conjunction with each other. (Zatsiorsky & Yakunin, 1991). Fundamentally, from a biomechanical perspective, the joint kinematics of five major joints in the body can be used to define the performance of the