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ABSTRACT In a sprint start, the athlete takes up a position with their hands just behind a line, arms vertical, feet generally placed about a shoe length apart, and the hips rising above the line of the head. Mistakes in this position influence the execution of the low-sprint start, and can drastically influence the initial running speed and acceleration achieved by the athlete. Common mistakes occur due to the misconception that athletes must also lean forward, bringing the shoulders ahead of their hands and putting pressure on them. A standard approach to identify sprint start mistakes is to use a stick or weighted string to drop down from the shoulders. The effective implementation of this approach depends on the coach's experience and remains a significant challenge. In this study, a three-dimensional motion capture system with the Vicon® Plug-in-Gait model was used to characterize the kinematic parameters that influence the execution of low-sprint start in six high-performance athletes. The main kinematic parameters are reaction time, stride length, and stride time. The obtained results demonstrate the potential utility of a three-dimensional motion capture system to assess the kinematic parameters of low-sprint start in high-performance athletes.
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BACKGROUND: The impact of obesity on total hip arthroplasty has been discussed. However, there is a lack of follow-up study on the patients with different body mass indexes using three-dimensional gait analysis. OBJECTIVE: To investigate the effect of body mass index on the early-term functional recovery after total hip arthroplasty by three-dimensional gait analysis. METHODS: Sixty patients who underwent total hip arthroplasty at Department of Joint Surgery of Affiliated Zhongshan Hospital of Dalian University from January 2017 to June 2018 were enrolled. According to the body mass index at admission, they were divided into overweight group (body mass index ≥ 25 kg/m2) and normal group (body mass index 0.05). The operation time in the overweight group was significantly longer than that in the normal group (P=0.000). (2) In terms of time-distance parameters, there was no significant difference in the stride length, stride frequency and mean velocity between two groups. The stride length in the overweight group was smaller than that in the normal group (1.08±0.18 vs. 1.35±1.45 m). (3) The range of motion of each planes of hip joint in the overweight group was significantly less than that in the normal group (P < 0.05). (4) In terms of kinetic parameters, the peak torque of hip flexion in the overweight group was significantly less than in the normal group (P=0.011). There was no significant difference in the peak torque of hip extension between two groups (P=1.000). (5) To conclude, obesity has certain effect on the early functional recovery after total hip arthroplasty.
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Objective To analyze the gait kinematics parameters of patients with unilateral leg amputation after wearing prosthesis using the computer assisted rehabilitation environment (CAREN) gait assessment system,and the reasons for the differences.Methods Nine patients with unilateral mid-leg amputation were selected as the prosthesis group,and 11 healthy subjects were selected as the standard group.The gait kinematics parameters of the two groups were collected,processed and analyzed by using the CAREN gait evaluation system.Results The gait phase index of the prosthetic limb group was (0.88±0.04).Significant differences were observed between the prosthetic and healthy limbs in terms of step length,stance phase percentage,maximum hip extension angle and maximum knee flexion angle,maximum dorsiflexion and plantar flexion angle of the ankle joint during the stance phase,as well as the dorsiflexion angle of ankle joint during heel strike to the ground (P＜0.05).Moreover,there were significant differences between the affected limbs of the prosthetic limb group and limbs of the standard group in terms of the walking speed,gait cycle,stride length,percentage of stance phase,hip flexion angle,knee flexion and ankle dorsiflexion during heel strike,maximum hip extension and flexion angle,maximum dorsi-and plantar-flexion of ankle joint during stance phase (P＜0.05).Conclusion The relative symmetry of the gait of the unilateral leg amputee is (0.88±0.04),with their kinematics parameters of the prosthetic limb significantly weaker than those of the contralateral side and the healthy controls.
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Objective To analyze temporal and kinematic parameters of video fluoroscopic images of swallowing using a digital acquisition and analysis system and to verify the reliability of this method.Methods Eighteen patients with dysphagia were requested to completed six swallows (3 ml and 5 ml of thin liquid, thick liquid, and paste mixed with 600 kg/m3 barium sulfate suspension) in the natural sitting position.Video fluoroscopy was used to measure the oral transit times, soft palate elevation times, hyoid movement times, laryngeal closure times, cricopharyngeal muscle opening times, hyoid anterior movement (HAM) , hyoid superior movement (HSM) , cricopharyngeal muscle opening diameter and pharyngeal constriction rate.Each was extracted from the videos four times by two raters working separately with an interval of 4 weeks between the sets of evaluations.Results Reliability varied among the different observations.HAM and HSM showed inter-rater reliability between 0.41 and 0.60 and intra-rater reliability between 0.61 and 0.80.The other observations all demonstrated acceptable reliability.Conclusion The self-designed digital acquisition and analysis system tested showed acceptable reliability and could be applied to analyze swallowing function clinically.
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O tipo de exercício, a intensidade e a frequência são fatores importantes para produzir mudanças na velocidade de andar. O objetivo do estudo foi comparar os efeitos de diferentes tipos de exercício nos parâmetros cinemáticos do andar de idosas, considerando as características antropométricas, a capacidade funcional e o nível de atividade física. Participaram do estudo 56 idosas que foram agrupadas de acordo com o envolvimento, a mais de seis meses, na prática específica de uma atividade: dança (n = 10), musculação (n = 10), hidroginástica (n = 12) e caminhada (n = 11). Além disso, um grupo de idosas inativas (n = 13), sem envolvimento em atividade física regular por pelo menos dois meses, também participou do estudo. Foram mensurados o nível de atividade física (Questionário de Baecke), a capacidade funcional (Bateria da AAHPERD) e os parâmetros cinemáticos do andar (comprimento da passada e do passo, duração e velocidade da passada, cadência e duração das fases de suporte simples, balanço e duplo suporte). Os resultados revelaram que o nível de atividade física do grupo Controle foi diferente dos demais grupos que praticam atividades físicas. Em relação à capacidade funcional, apenas o componente força apresentou diferenças entre os grupos, indicando que o grupo Controle difere do grupo musculação. Quanto às variáveis do andar, o grupo Controle foi estatisticamente diferente apenas do grupo dança, tanto no comprimento do passo como no comprimento da passada. Pode-se concluir que a capacidade funcional e os parâmetros do andar dos idosos ativos e sedentários apresentam poucas diferenças.
Exercise type, intensity and frequency are important factors to produce changes in gait velocity. The aim of this study was to compare the effects of different exercise types in the gait kinematic parameters in elderly women, whereas anthropometry, functional capacity and physical activity level are considered. Fifty-six elderly women were grouped according to their specific physical activity (practice for more than 6 months): dancing (n = 10), strength training (n = 10), aquatic exercise training (n = 12) and walking (n = 11). In addition, an inactive female older group (n = 13), without engagement in regular physical activity for at least 02 months, participated in the study. The physical activity level (Baecke Questionnaire), functional capacity (AAHPERD battery) and the gait kinematic parameters (stride and step length, stride velocity, cadence and single support phases, swing and double support duration) were measured. The results showed that the physical activity level in the control group was different from the one in the other groups (physically active). In relation to functional capacity, only the strength component was different between groups, indicating that the control group differs from the strength training group. Regarding the gait parameters, the control group was statistically different from the group dancing regarding stride and step length. The results of this study indicate that the functional capacity and gait parameters of active and sedentary elderly females present few differences.
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Humans , Male , Female , Aged , Aged, 80 and over , Motor Activity/physiology , Exercise Therapy , Aging/physiology , Exercise/physiology , Exercise Movement Techniques , Sedentary BehaviorABSTRACT
@#ObjectiveTo study basic pattern of normal youth in gait analysis.Methods28 healthy young persons as experimental subjects were studied. The gait analysis system based on digital video and digital image processing was employed to obtain kinematic parameters.ResultsThe means and standard deviations of kinematic parameters of normal youth were obtained. The differences of gait patterns between males and females were compared. The correlations between gait parameters and height, weight were analyzed respectively.Conclusions It is recommended that the values of the gait parameters and the trends obtained can be used as a standard gait pattern of normal youth. Statistically significant differences exist between the males and the females for most of the gait parameters. Furthermore, the differences of the values of gait parameters between the males and the females are not led only by the difference of height except very few parameters.