Abstracts / Gait & Posture 30S (2009) S1–S153
P42 Consistency of a biomechanical foot model for clinical gait analysis Esteban Pavan ∗ , Joanna Kahwagi, Carlo Frigo Movement Biomechanics and Motor Control Lab, TBM LabBioengineering Department-Politecnico di Milano, Milan, Italy Summary A model of the foot, derived from the Heidelberg Foot Measurement Method (HFMM) [1], was implemented in order to analyse pathological gait. The present work deals with validation and is based on a comparison between a group of healthy adults and data previously published. Furthermore, the effect of changing the position of some relevant markers was tested. It appeared that these variations can introduce misleading bias in most angles. Conclusions Despite critical location of some markers the consistency of the HFMM was sufficient for obtaining the relevant foot function information. In healthy subjects, most of the projection angles showed not significant differences with the published control data. However the marker placement is to be precisely defined in order to avoid uncertainties and misinterpretations. Introduction Different biomechanical models of the foot have been proposed for clinical movement analysis [2], each considering different anatomical segments, functional axis, as well as marker positioning. After defining segments and relative constraints, at least three reference points for each segment are conventionally used. The HFMM proposed in 2005 by Simon et al. [1] is based instead on a different approach in which constraints between foot segments are not defined: segmental motion is reduced to rotational angles projected on planes perpendicular to a rotation axis. Relevant clinical information regarding foot function can be derived in this way. Patients and methods The HFMM’s multi-segment foot model involves the use of 17 skin mounted markers which were placed on foot and shank; whereas a “heel alignment device” was made and used for standardizing the heel markers positioning, as proposed by the authors [1]. Nine normal subjects (aged 27.7 ± 7.9 years) with no known foot abnormalities were chosen. Kinematic data of five barefoot strides from each side were collected using SMART-E (BTS, Italy). Twelve independent functional angles were calculated by using the projection angles method. This consists in obtaining the angle between two segments by projecting them into the plane perpendicular to the axis of rotation. An analysis of the model’s sensitivity to the marker’s placement was also performed by intentionally changing the position of 4 markers: navicular, head and base of first metatarsal and base of fifth metatarsal. Results Most of the projected angles matched well the data published by the HFMM authors. Concerning sensitivity, the most significant differences resulted after medially placing the navicular marker, while mainly a bias was observed in subtalar inversion (6◦ ), medial arch (15◦ ) and medial arch inclination (18◦ ). Asymmetries between left and right foot were easily identified (considering the intra-trials variability) but no particular angles were found to be more prone to asymmetry than others, and their extent varied between subjects. Discussion Although a reduced intra-subject variability was observed in our data, a biasing associated to marker placement was evident,
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demonstrating that an uniform criteria of marker placement can improve the sensibility of the HFMM. References [1] Simon, et al. Gait Posture 2006;23:411–24. [2] Kaufman KR.Foot Models First Joint ESMAC-GCMAS Meeting. 2006.
doi:10.1016/j.gaitpost.2009.08.162 P43 Gait adaptation in infants at mild risk for neuromotor disability receiving a treadmill intervention Rosa Angulo Barroso 1,∗ , Li-Chiou Chen 3 , Julia Looper 2 , Chad Tiernan 2 , Dale Ulrich 2 1
CHGD, University of Michigan, Ann Arbor, MI, United States Kinesiology, University of Michigan, Ann Arbor, MI, United States 3 School of Physical Therapy, National Taiwan University, Taipei, Taiwan 2
Summary A randomized pre-ambulatory treadmill training (TMT) intervention in infants at mild-risk for neuromotor disability (mild-risk) was conducted to examine effects on walking onset, strategy adopted to cross an obstacle and gait adjustments generated. Conclusions Pre-ambulatory TMT in mild-risk infants resulted in greater gait adjustments while no effects where observed on walking onset or strategy adopted to cross the obstacle. Introduction Infants who suffer complications during the perinatal period may show transient neuromotor delay or even neuromotor disability, such as cerebral palsy (CP) [1]. TMT has been sparsely used as an intervention tool in infants and children with disabilities [2]. The purpose of this study was to investigate the gait adaptation capabilities of mild-risk infants with or without pre-ambulatory treadmill training. Patients/materials and methods Twenty-five mild-risk infants were randomly assigned to either a control (C, n = 12) or an experimental (E, n = 13) group. During the intervention period, infants in the E group received home-based TMT for 8 min/day, 5 days/week until the onset of independent walking. Monthly assessments were conducted for all infants at their homes. Once the infant could independently walk for 8–10 continuous steps, his/her gait ability while traversing an obstacle (3 m long, 5 cm diameter foam-padded bar) was examined and re-evaluated again 3 and 6 months later (visits 1–3). Obstacle conditions included 0% (visits 1–3), 10% (visit 2, 3), and 20% of leg length (visit 3). Obstacle clearance strategy was evaluated in all infants. In addition, infants’ footprints were recorded via a GaitRite mat to calculate the spatiotemporal gait parameters (Fig. 1). Results The results showed that both groups attained independent walking at comparable corrected ages (C: 14.3 ± 2.3; E: 14.4 ± 2.4 months). In the first gait visit, infants showed higher proportion (∼60%) of walking over the obstacle than falling or crawling behaviors (p < 0.01). By 5–6 months post-walking, the rate of walking over the obstacle had increased to about 90%. No group difference was found in the strategy of obstacle crossing. Analysis of the gait adjustments showed that infants in the E group increased their step width before crossing the obstacle in all conditions in visits 2 and 3 while infants in the C group only demonstrated such adjustment
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Abstracts / Gait & Posture 30S (2009) S1–S153
Fig. 1. Gait adjustments in step width (presented as difference from baseline) at the high obstacle conditions in visits 2 and 3.
in the 10% and 20% high obstacle conditions. For the step crossing over and the ones after the obstacle, E group infants increased their step width in the high obstacle conditions while infants in the C group did not show such adjustment (adjusted p < 0.05). In addition, infants in the E group, comparing to those in the C group, showed greater shortened step length when approaching the obstacle in the 20% condition in visit 3 (adjusted p = 0.0591). Discussion The TMT intervention did not modify the onset of independent walking or the strategy infants adopted when crossing an obstacle. However, infants with pre-ambulatory TMT seemed to show more advanced adjustment on the preparatory and over the obstacle steps. However, their gait adjustments were extended passed the obstacle compared to the control group. Our results suggest the specificity of TMT effects in mild-risk infants. References [1] Vohr BR, et al. Pediatrics 2005;116:635–43. [2] Angulo-Barroso, et al. Gait and Posture 2008;27:231–8.
doi:10.1016/j.gaitpost.2009.08.163 P44 Effect of attentional focus rehabilitative training on the gait performance of patients with multiple sclerosis Mohsen Shafizadeh ∗ , Baharak Mohammadi
multiple sclerosis patients. Therefore, the aim of present study was clarify the effectiveness of various attention of focus cuing training on the performance of gait pattern in these patients. Patients/materials and methods 12 MS patients with average disability scale of 3.4 recruited voluntarily and participated in the 2-month clinical intervention with three phases: baseline, internal-focus, and external-focus. The order of control and treatment phases was randomised for each candidate. A treadmill that equipped with force sensors and motion analysis camera were used for measuring gait performance. The average kinematic and kinetic data were computed for 2 min of each condition for each session. Results Repeated measures ANOVA results have shown the significant main effect for attention focus, so that the external-focus phase was produced longer step and stride length and faster step speed with greater energy expenditure (P < .05) than other phases, but there were no significant effects for reaction force and gait timing. Discussion The external-attention of rehabilitative training on the treadmill could produce positive improvement in some gait parameters of multiple sclerosis patients and better automaticity selforganization as has mentioned in the constrained action hypothesis [8]. Thus, it is needed to integrate of regular training with perceptual-motor, and cognitive training for better results in rehabilitation sessions.
Sport Sciences Faculty, Tehran, Tehran, Islamic Republic of Iran Summary The rehabilitation program for multiple sclerosis patients have been studied in the recent years with emphasize on perceptual practice [1]. The cueing technique is one of them. Its aim is to apply verbal or pictorial stimulus for changing the movement dynamics [2]. This study has carried out with two different attentional focus training and a control phases. Conclusions External-attention intervention had better performance than other conditions for gait parameters after training period. Introduction Multiple sclerosis is one of the neural diseases that results in motor disability and movement patterns malfunction [3]. Any information as a kind of instruction, feedback, guidance, and modelling, can inform the performer from the execution of movement and correct the movement patterns [4]. The effectiveness of cuing technique as a form of attention of focus rehabilitative training on the movement pattern of motor disabled patients have been demonstrated in previous studies [5–7], but few of them have carried out in
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doi:10.1016/j.gaitpost.2009.08.164 P45 Reproducibility of walking patterns in patients with arthrogryposis multiplex congenita Felix Stief 1,∗ , Verena Döderlein 3 1
Metzler 2 , Harald
Böhm 1 , Leonhard
Gaitlab, Orthopaedic Clinic for Children, Aschau i. Chiemgau, Germany