Quantifying lumbar–pelvis coordination during gait using a modified vector coding technique

Abstract

Q1Please confirm that given names and surnames have been identified correctly and are presented in the desired order. Q2The reference given here is cited in the text but is missing from the reference list -please make the list complete or remove the reference from the text: "Seay et al., (2011)", "Chang et al., 2008", "Seay et al., 2006", "Callaghan et al., 1999". Q3Please check the hierarchy of the section headings and correct if necessary. Thank you for your assistance. b s t r a c tThe complexity of human gait patterns has become a topic of major interest in motor control and biomechanics. Range of motion is still the preferred method to quantify movement impairment, however, within these traditional linear measures, the inter-segmental coordination and movement variability is normally ignored. A dynamical systems approach using vector coding and circular statistics provides non-linear techniques to quantify coordination and variability. This study provides comprehensive vector coding and circular statistics calculations. Additionally, pelvis-lumbar coordination and coordination variability data obtained from ten healthy young male participants during five walking trials using an optoelectronic system is provided. This novel data can form the baseline information for future studies in this area of research. Finally, a new illustration to present coordination and coordination variability information of gait kinematics, combining the output from the modified vector coding technique with traditional time-series segmental angle data is presented. This technique, when applied to single patients can be beneficial to assess the effect of an intervention on the patient-specific intersegmental coordination pattern with implications to clinical setting.

Locomotor Coordination, Visual Perception and Head Stability during Running

“…Among the various coordination analysis techniques, vector coding (VC) has commonly been employed in the locomotion literature. Modified VC allows easier interpretation of biomechanical running data [56] and provides useful metrics in understanding the organization of movements such as phase dominancy (e.g., in-phase or anti-phase) and segmental dominancy based on spatial changes [57,58]. However, currently, modified VC has not been used to assess how coordinative changes contribute to stabilize the head during running.…”

A quantitative comparison of two kinematic protocols for lumbar segment motion during gait

“…In short, markers were placed on a rigid mount attached to the lumbar spine at the level of the 3 rd lumbar vertebra (L3) [8,15]. The mount was made of lightweight plastic with a small rectangular base that attached directly to the skin using double sided sticky tape (Figs.1A and Figs.1B).…”

“…Many alternative trunk kinematic models are described in the literature and range in complexity from skin surface markers or rigid clusters placed only on the thorax [1, [3][4][5], to indepth models that include modeling of the lumbar spine [6][7][8][9]. Skin surface markers placed along the lumbar spine allow only a 2-dimensional representation of the movement.…”

“…This rigid segment assumption is essential if inverse dynamics are to be calculated further up the kinematic chain [12]. Kinematic modeling of the spine as a rigid segment could involve the placement of a set of skin surface markers placed over the lumbar region at specifically defined points [9,13,14], or alternatively as a rigid cluster mount placed at a specific anatomical location on the lumbar spine [8,11,15,16]. However, when rigid cluster mounts have been used, the specific point of application of the mount can vary between studies [8,11,15,16].…”

“…The second protocol is a rigid cluster protocol with the cluster placed on the third lumbar vertebrae (L3). This protocol has also recently been used in a number of studies [8,15] and it was felt it would provide an appropriate measure of lumbar segment motion.…”