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1.
《European Journal of Sport Science》2013,13(1):21-30
Abstract One of the most fundamental skills on the pommel horse is double leg circles (circles). Circles can be performed on all parts of the pommel horse. It was hypothesized that the different sets of physical constraints of the apparatus require a gymnast to adapt circles technique. The purpose of this study was to quantify how gymnasts modify their technique during circles to accommodate different physical obstacles due to different support surfaces and body orientations. To investigate these adaptations, a comparison of the two most common circles on pommel horse – namely, circles in cross support (cross-circles) and circles in side support (side-circles) – was carried out. Seven elite male gymnasts performed three sets of 10 cross-circles and side-circles on a pommel horse. Three-dimensional coordinates were acquired using 12 Qualisys ProReflex motion tracking cameras operating at 120 Hz. Temporal characteristics, the motion of the centre of mass, and the body angles – flexion and lateral flexion – were analysed. We found that cross-circles took less time to complete a single circle (0.92±0.02 vs. 0.95±0.02 s), had a smaller ratio for the rear support phase (0.15±0.02 vs. 0.18±0.03), a narrower supporting-hand distance (0.33±0.03 vs. 0.52±0.00 m), greater flexion of the body over the rear support phase (44±12° vs. 27±8°), and less lateral flexion of the body over the single-hand support phase (entry: 20±5° vs. 35±3°; exit: 26±4° vs. 33±4°) than side-circles. Our results suggest that gymnasts adapt their technique to the physical constraints imposed by the shape of the pommel horse and the location and orientation of the circles. Cross-circles were characterized by a high rear support position with a narrower hand-spacing, which would require excellent shoulder flexibility and strength. Consequently, lack of these traits may explain the need for greater body flexion in cross-circles than in side-circles during rear support. Understanding the technical differences will facilitate an effective transfer of the technical similarities among different types of circles. 相似文献
2.
Toshiyuki Fujihara Pierre Gervais 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(1):34-47
The aim of this study was to investigate the influence of a suspended aid on the reaction forces during a basic skill on pommel horse. Twenty gymnasts performed three sets of 10 circles with and without a suspended aid on a pommel horse under which two force plates were set. The results confirmed that the suspended aid could reduce the magnitude of the pommel reaction forces during circles while maintaining the general loading pattern. On the left hand, the average and peak forces were attenuated to 0.59 body weight (BW) and 0.85 BW from 0.76 BW and 1.13 BW, respectively. The right hand experienced slightly larger forces with no-aid trials, but the asymmetry between the hands decreased with the aid. Despite a relatively large variability, all gymnasts experienced smaller impact peak forces with the aid. A suspended aid is most commonly used for a beginner gymnast as an introduction to pommel horse exercises. However, this study confirmed that it can also be useful for all levels of gymnasts who would like to practice pommel horse exercises with reduced pommel reaction forces for a purpose such as a progression for learning a new skill, control of training volume, or rehabilitation. 相似文献
3.
Fujihara T Gervais P 《Sports biomechanics / International Society of Biomechanics in Sports》2012,11(1):34-47
The aim of this study was to investigate the influence of a suspended aid on the reaction forces during a basic skill on pommel horse. Twenty gymnasts performed three sets of 10 circles with and without a suspended aid on a pommel horse under which two force plates were set. The results confirmed that the suspended aid could reduce the magnitude of the pommel reaction forces during circles while maintaining the general loading pattern. On the left hand, the average and peak forces were attenuated to 0.59 body weight (BW) and 0.85 BW from 0.76 BW and 1.13 BW, respectively. The right hand experienced slightly larger forces with no-aid trials, but the asymmetry between the hands decreased with the aid. Despite a relatively large variability, all gymnasts experienced smaller impact peak forces with the aid. A suspended aid is most commonly used for a beginner gymnast as an introduction to pommel horse exercises. However, this study confirmed that it can also be useful for all levels of gymnasts who would like to practice pommel horse exercises with reduced pommel reaction forces for a purpose such as a progression for learning a new skill, control of training volume, or rehabilitation. 相似文献
4.
In the third study of this series, we examined how circles with a suspended aid would vary depending of the gymnast's level of expertise. We analysed circles with the aid performed by three groups of eight gymnasts: expert, intermediate, and developing groups. The gymnasts for the expert and intermediate groups were selected from the previous studies based on judges' evaluation of their non-aid circles. The developing group of eight gymnasts, who were unable to perform circles on pommel horse without an aid, were added to this study and performed three sets of 10 circles on the pommel horse with the aid. Discriminative biomechanical variables identified in the previous two studies were used to compare circles with the aid among the three groups. As a result, the expert group demonstrated a larger pommel reaction force and a smaller aid reaction force than the other two groups, implying that they were less dependent on the aid. The smaller aid reaction force resulted in a smaller net hip joint moment. Furthermore, the expert group showed a shorter total duration and a greater shoulder excursion. In summary, the suspended aid can be used in a progressive manner depending on the gymnast's level of expertise. 相似文献
5.
This is the second study of the series, and its aim was to investigate the influence of using the suspended aid on circle kinetics. In addition to the kinematic data recorded for part one (Fujihara & Gervais, 2012), the pommel reaction forces and the force applied from the suspended aid (aid reaction force) were analysed in relation to the motion of a whole-body mass centre. The hip joint moment was also computed by combining all segments in the lower extremities into a single rigid segment. Generally, the use of the aid changed the magnitude of the mass-centre trajectory or horizontal pommel reaction forces but not their patterns. The results also showed that the net hip joint moment was altered during circles with the aid. In summary, a suspended aid can be used as a progression for a variety of goals because it allows gymnasts to practise circles which would not be possible without the aid. When a suspended aid is used, however, practitioners should be aware of the possible kinetic alteration caused by the external force from the aid. 相似文献
6.
Abstract This is the second study of the series, and its aim was to investigate the influence of using the suspended aid on circle kinetics. In addition to the kinematic data recorded for part one (Fujihara & Gervais, 2012), the pommel reaction forces and the force applied from the suspended aid (aid reaction force) were analysed in relation to the motion of a whole-body mass centre. The hip joint moment was also computed by combining all segments in the lower extremities into a single rigid segment. Generally, the use of the aid changed the magnitude of the mass-centre trajectory or horizontal pommel reaction forces but not their patterns. The results also showed that the net hip joint moment was altered during circles with the aid. In summary, a suspended aid can be used as a progression for a variety of goals because it allows gymnasts to practise circles which would not be possible without the aid. When a suspended aid is used, however, practitioners should be aware of the possible kinetic alteration caused by the external force from the aid. 相似文献
7.
In this study, we investigated whether video modelling can enhance gymnasts' performance of the circle on a pommel horse. The procedure associated expert-modelling with self-modelling and quantitative performance analysis. Sixteen gymnasts were randomly assigned to one of two groups: (1) a modelling group, which received expert- and self-modelling, and performance feedback, or (2) a control group, which received no feedback. After five sessions of training, an analysis of variance with repeated measures indicated that the gains in the back, entry, front, and exit phases of the circle were greater for the modelling group than for the control group. During the training sessions, the gymnasts in the modelling group improved their body segmental alignment during the back phase more quickly than during the other phases. As predicted, although both groups performed the same number of circles (300 in 5 days, with 10 sequences of 6 circles), the modelling group improved their body segmental alignment more than the control group. It thus appears that immediate video modelling can help to correct complex sports movements such as the circle performed on the pommel horse. However, its effectiveness seemed to be dependent on the complexity of the phase. 相似文献
8.
Abstract In this study, we investigated whether video modelling can enhance gymnasts' performance of the circle on a pommel horse. The procedure associated expert-modelling with self-modelling and quantitative performance analysis. Sixteen gymnasts were randomly assigned to one of two groups: (1) a modelling group, which received expert- and self-modelling, and performance feedback, or (2) a control group, which received no feedback. After five sessions of training, an analysis of variance with repeated measures indicated that the gains in the back, entry, front, and exit phases of the circle were greater for the modelling group than for the control group. During the training sessions, the gymnasts in the modelling group improved their body segmental alignment during the back phase more quickly than during the other phases. As predicted, although both groups performed the same number of circles (300 in 5 days, with 10 sequences of 6 circles), the modelling group improved their body segmental alignment more than the control group. It thus appears that immediate video modelling can help to correct complex sports movements such as the circle performed on the pommel horse. However, its effectiveness seemed to be dependent on the complexity of the phase. 相似文献
9.
A suspended aid is popular for learning circles and for refining circle technique on pommel horse. The aim of this study was to investigate the effect of using a suspended aid on the biomechanical characteristics of circles. This first study focused specifically on the spatio-temporal characteristics of circles. Eighteen gymnasts performed three sets of 10 circles with and without a suspended aid on a pommel horse under which two force plates were set. Three-dimensional coordinates were acquired using 13 Qualisys motion tracking cameras operating at 100 Hz. The results showed that circles with the aid were characterised by a smaller body flexion angle, a greater shoulder angle, a greater ankle circle diameter, earlier hand releases, and a longer total duration. In contrast, the body lateral flexion angle, the arm-leaning angle, and the shoulder circle diameter remained relatively similar to circles without the aid. It was confirmed that circles with the aid actually appeared to be more desirable in terms of the movement amplitude. In this sense, a suspended aid could function as spotting, which is often used for a progression to learn gymnastics skills and to let gymnasts experience a desired movement pattern. 相似文献
10.
Yoshiaki Takei J. Hubert Dunn Erik Blucker 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(2):141-162
The 16 highest‐scored Roche vaults (G1) performed during the 2000 Olympic Games were compared with those receiving the 16 lowest‐scores (G2). A 16‐mm motion picture camera operating at 100 Hz recorded the vaults during the competition. The results of t tests (p < .05) indicated G1, compared to G2, had (a) shorter time of board support, greater normalised average upward vertical force and backward horizontal force exerted by the board, greater change in the vertical velocity while on the board, and greater vertical velocity at board take‐off, (b) comparable linear and angular motions in pre‐flight, (c) smaller backward horizontal impulse exerted by the horse, smaller loss of the horizontal velocity while on the horse, and greater horizontal and vertical velocities at horse take‐off, (d) greater height and larger horizontal distance of post‐flight, (e) higher body mass centre at knee release, and (f) higher mass centre, greater normalised moment of inertia, and smaller vertical velocity at mat touchdown. Therefore, gymnasts and coaches should focus on sprinting the approach; blocking and pushing‐off the take‐off board rapidly and vigorously; departing the board with a large vertical velocity; exerting large downward vertical force and small forward horizontal force from the handstand position while on the horse; departing the horse with large horizontal and vertical velocities; and completing the majority of the double salto forward near the peak of trajectory and releasing the knees above the top of the horse to prepare for a controlled landing. 相似文献
11.
Takei Y Dunn JH Blucker E 《Sports biomechanics / International Society of Biomechanics in Sports》2003,2(2):141-162
The 16 highest-scored Roche vaults (G1) performed during the 2000 Olympic Games were compared with those receiving the 16 lowest-scores (G2). A 16-mm motion picture camera operating at 100 Hz recorded the vaults during the competition. The results of t tests (p < .05) indicated G1, compared to G2, had (a) shorter time of board support, greater normalised average upward vertical force and backward horizontal force exerted by the board, greater change in the vertical velocity while on the board, and greater vertical velocity at board take-off, (b) comparable linear and angular motions in pre-flight, (c) smaller backward horizontal impulse exerted by the horse, smaller loss of the horizontal velocity while on the horse, and greater horizontal and vertical velocities at horse take-off, (d) greater height and larger horizontal distance of post-flight, (e) higher body mass centre at knee release, and (f) higher mass centre, greater normalised moment of inertia, and smaller vertical velocity at mat touchdown. Therefore, gymnasts and coaches should focus on sprinting the approach; blocking and pushing-off the take-off board rapidly and vigorously; departing the board with a large vertical velocity; exerting large downward vertical force and small forward horizontal force from the hand-stand position while on the horse; departing the horse with large horizontal and vertical velocities; and completing the majority of the double salto forward near the peak of trajectory and releasing the knees above the top of the horse to prepare for a controlled landing. 相似文献
12.
The optimum pre-flight characteristics of the Hecht and handspring somersault vaults were determined using a two-segment simulation model. The model consisted of an arm segment and a body segment connected by a frictionless pin joint, simulating the vault from the Reuther board take-off through to landing. During horse contact, shoulder torque was set to zero in the model. Five independent pre-flight variables were varied over realistic ranges and an objective function was maximized to find the optimum pre-flight for each vault. The Hecht vault required a low trajectory of the mass centre during pre-flight, with a low vertical velocity of the mass centre and a low angular velocity of the body at horse contact. In contrast, the optimum handspring somersault required a high pre-flight trajectory, with a high angular velocity of the body and a high vertical velocity at horse contact. Despite the simplicity of the model, the optimum pre-flights were similar to those used in competitive performances. 相似文献
13.
The aim of this study was to compare the somersaulting techniques used in the 16 highest-scoring and 16 lowest-scoring Roche vaults. Our hypothesis was that the gymnasts performing the highest-scoring Roche vaults would demonstrate a better technique than those performing the lowest-scoring Roche vaults while on the horse (pushing off the horse more effectively), somersaulting (executing most of the required somersaults higher in flight), and landing (showing a greater control). A 16-mm motion picture camera, operating at 100 Hz, recorded the vaults during the official competition. The two-dimensional direct linear transformation was used for spatial reconstruction. The results of t-tests (P < 0.05) indicated that, compared with the low-scoring gymnasts, the high-scoring gymnasts had: (1) greater height of body centre of mass and a more fully extended body position at the horse take-off; (2) greater height of body centre of mass at the peak of post-flight, knee release, and touchdown on the mat; (3) greater horizontal and vertical displacements of body centre of mass, greater somersaulting rotation, and longer time from the knee release to mat touchdown; and (d) markedly smaller landing point deductions. In conclusion, a successful Roche vault is likely when the focus is on: (a) leaving the horse with a large vertical velocity in an extended body position to achieve a high trajectory of centre of mass by first extending the legs, then immediately pushing off the horse vigorously, using the muscles of the upper extremity; (b) grasping the knees immediately after the take-off from the horse, achieving the tightly tucked body position early during the ascent to the peak, and completing two-thirds of the required somersaults at a great height; (c) releasing the knees and extending the body above the top level of the horse; and (d) contacting the mat with a high body centre of mass position. 相似文献
14.
Abstract The aim of this study was to compare the somersaulting techniques used in the 16 highest-scoring and 16 lowest-scoring Roche vaults. Our hypothesis was that the gymnasts performing the highest-scoring Roche vaults would demonstrate a better technique than those performing the lowest-scoring Roche vaults while on the horse (pushing off the horse more effectively), somersaulting (executing most of the required somersaults higher in flight), and landing (showing a greater control). A 16-mm motion picture camera, operating at 100 Hz, recorded the vaults during the official competition. The two-dimensional direct linear transformation was used for spatial reconstruction. The results of t-tests (P < 0.05) indicated that, compared with the low-scoring gymnasts, the high-scoring gymnasts had: (1) greater height of body centre of mass and a more fully extended body position at the horse take-off; (2) greater height of body centre of mass at the peak of post-flight, knee release, and touchdown on the mat; (3) greater horizontal and vertical displacements of body centre of mass, greater somersaulting rotation, and longer time from the knee release to mat touchdown; and (d) markedly smaller landing point deductions. In conclusion, a successful Roche vault is likely when the focus is on: (a) leaving the horse with a large vertical velocity in an extended body position to achieve a high trajectory of centre of mass by first extending the legs, then immediately pushing off the horse vigorously, using the muscles of the upper extremity; (b) grasping the knees immediately after the take-off from the horse, achieving the tightly tucked body position early during the ascent to the peak, and completing two-thirds of the required somersaults at a great height; (c) releasing the knees and extending the body above the top level of the horse; and (d) contacting the mat with a high body centre of mass position. 相似文献
15.
Clint Hansen Nasser Rezzoug Philippe Gorce Gentiane Venture Brice Isableu 《Journal of sports sciences》2016,34(9):878-885
We examined the role of rotation axes during an overarm throwing task. Participants performed such task and were asked to throw a ball at maximal velocity at a target. The purpose of this study was to examine whether the minimum inertia axis would be exploited during the throwing phases, a time when internal–external rotations of the shoulder are particularly important. A motion capture system was used to evaluate the performance and to compute the potential axes of rotation (minimum inertia axis, shoulder–centre of mass axis and the shoulder–elbow axis). More specifically, we investigated whether a velocity-dependent change in rotational axes can be observed in the different throwing phases and whether the control obeys the principle of minimum inertia resistance. Our results showed that the limbs’ rotational axis mainly coincides with the minimum inertia axis during the cocking phase and with the shoulder–elbow axis during the acceleration phase. Besides these rotation axes changes, the use of interaction torque is also sequence-dependent. The sequence-dependent rotation axes changes associated with the use of interaction torque during the acceleration phase could be a key factor in the production of hand velocity at ball release. 相似文献
16.
Veronique Colman Ulrik Persyn Daniel Daly Valere Stijnen 《Journal of sports sciences》2013,31(7):653-665
The aim of this study was to establish differences in intra-cyclic horizontal velocity variation of the body's centre of mass in breaststroke swimmers with flat and undulating styles. Vertical eel-like body waving and trunk rotations were measured to distinguish styles. To reconstruct trunk extension and kyphosis in the poorly visible zone close to the water surface, a semi-automated video-analysis system was developed. From 45 internationallevel swimmers examined, two groups of women and two groups of men were identified, those using the most undulating and those using the flattest styles. Among the men with the flattest style, the maximum and minimum horizontal velocity of the body's centre of mass differed by 76% from the mean swimming velocity; among the women with the most undulating style, the figure was 53%. In the most undulating style, less horizontal velocity variation of the body's centre of mass could be explained by movements of the body parts above the water surface, creating a transfer of momentum: a quick backward upper trunk rotation generates resistance and a quick forward shoulder girdle and upper arm movement, followed by a quick forward upper trunk and head rotation, generates propulsion. In addition, during an upward leg kick, some swimmers generated propulsion similar to that seen in eels. 相似文献
17.
Kazumichi Ae Sekiya Koike Norihisa Fujii Michiyoshi Ae Takashi Kawamura 《Sports biomechanics / International Society of Biomechanics in Sports》2017,16(3):283-296
The purpose of this study was to investigate effects of the ground reaction forces on the rotation of the body as a whole and on the joint torques of the lower limbs associated with trunk and pelvic rotation in baseball tee batting. A total of 22 male collegiate baseball players participated in this study. Three-dimensional coordinate data were acquired by a motion capture system (250 Hz), and ground reaction forces of both legs were measured with three force platforms (1,000 Hz). Kinetic data were used to calculate the moment about the vertical axis through the body’s centre of mass resulting from ground reaction forces, as well as to calculate the torque and mechanical work in the lower limb joints. The lateral/medial ground reaction force generated by both legs resulted in the large whole body moment about its vertical axis. The joint torques of flexion/extension of both hips, adduction of the stride hip and extension of the stride knee produced significantly larger mechanical work than did the other joint torques. To obtain high bat-head speed, the batter should push both legs in the lateral/medial direction by utilising both hips and stride knee torques so as to increase the whole body rotation. 相似文献
18.
按国家器材标准安排少儿篮球教学内容探讨 总被引：1，自引：0，他引：1
张元文 《上海体育学院学报》2008,32(1):74-78
采用实验法、问卷调查法,对国家器材标准下少儿篮球教学内容的安排进行研究。认为:小学1年级学习原地运球及运球走技术,2年级学习行进间运球、行进间体前变向换手运球技术,3年级学习原地双手胸前传接球、原地单手肩上投篮技术,4年级学习行进间双手胸前传接球、行进间单手肩上投篮技术,5年级学习持球交叉步突破、行进间单手低手投篮技术,6年级学习原地跳起单手肩上投篮技术。初中阶段学习进攻基础配合及小学阶段学习的进攻技术在配合中的运用。 相似文献
19.
20.
In this study, we examined the effectiveness of auditory concurrent feedback on body segmental alignment during the circle movement performed on a pommel horse. Eighteen gymnasts were assigned to one of two groups: a concurrent auditory feedback group (experimental) or a control group that received no concurrent feedback. After 2 weeks of training (300 circles), the body segmental alignment (BSA) of the experimental group had improved by 2.3% between the pre test (85.7 +/- 4.8% BSA(max)) and the post test (87.7 +/- 4.0% BSA(max)). Furthermore, the results of a retention test administered 2 weeks after the post test revealed no decline in performance for the experimental group. No gains in body segmental alignment were found for the control group. It was concluded that augmented auditory feedback made available in real time can be used to correct complex movements, such as the circle movement on a pommel horse, and does not appear to lead to information-dependence despite the frequent administration of feedback. The auditory signal available in real time could help gymnasts to become more objective about their own intrinsic information necessary for the refinement of the circle movement. 相似文献