Methods of Determining Hip Joint Centre: Their Influence on the 3-D Kinematics of the Hip and Knee During the Fencing Lunge

Purpose. The lunge is a fundamental offensive fencing technique, common to all contemporary fencing styles. Therefore, when using 3-D kinematic analysis to quantify lower extremity rotations during the fencing lunge, it is important for researchers to correctly interpret this movement. Locating the centre of the hip is required to accurately quantify hip and knee joint rotations, with three non-invasive techniques using anatomical, functional and projection methods currently available for the estimation of hip joint centre. This study investigated the influence of these three techniques on hip and knee joint kinematics during the fencing lunge. Methods. Three-dimensional kinematics of the lunge were collected from 13 experienced epee fencers using an eight-camera motion capture system. The 3-D kinematics of the lunge were quantified using the three hip joint centre estimation techniques. Repeated measures ANOVAs were used to compare the discrete 3-D kinematic parameters, and intra-class correlations were employed to identify similarity across the 3-D kinematic waveforms from the three techniques. Results. The results indicate that whilst the kinematic waveforms were similar (R2 ≥0.96); significant differences in discrete parameters were also evident at both the hip and knee joint in the coronal and transverse planes. Conclusions. It appears based on these observations that different hip joint centre locations can significantly influence the resultant kinematic parameters and cannot be used interchangeably.