共查询到20条相似文献，搜索用时 46 毫秒
1.
Roman Farana Gerda Strutzenberger Timothy Exell Jiri Skypala Huw Wiltshire Gareth Irwin 《Journal of sports sciences》2019,37(13):1449-1456
The aim of the study was to determine if sex differences exist in the key elbow and wrist joint injury risk factors during different cartwheel (CW) and round-off (RO) techniques performed by young male and female artistic gymnasts. Sixteen active young gymnasts (8 males and 8 females) performed 30 successful trials of CW and RO with three different hand positions (parallel (10), T-shape (10) and reverse (10)). Synchronised kinematic and kinetic data were collected for each trial. Two-way repeated measures ANOVA (3 × 2, technique × sex) and effect-sizes (ES) were used for statistical analysis. In conclusion, female gymnasts exhibited greater normalised peak vertical ground reaction forces (VGRF), elbow and wrist compression forces and elbow internal adduction moments during CW and RO skills compared with male gymnasts. In both sexes, the parallel and reverse techniques increased peak VGRF, elbow and wrist compression forces and the elbow internal adduction moment. Increased elbow flexion resulted in decreased peak VGRF, elbow compression forces and elbow internal adduction moment. Injury risk factors including elbow extension and internal adduction moment with axial compression force suggest that a CW and RO in reverse and parallel techniques can be hazardous especially for young female gymnasts. 相似文献
2.
Roman Farana Daniel Jandacka Jaroslav Uchytil David Zahradnik Gareth Irwin 《Journal of sports sciences》2017,35(2):124-129
The aim of this study was to examine the biomechanical injury risk factors at the wrist, including joint kinetics, kinematics and stiffness in the first and second contact limb for parallel and T-shape round-off (RO) techniques. Seven international-level female gymnasts performed 10 trials of the RO to back handspring with parallel and T-shape hand positions. Synchronised kinematic (3D motion analysis system; 247 Hz) and kinetic (two force plates; 1235 Hz) data were collected for each trial. A two-way repeated measure analysis of variance (ANOVA) assessed differences in the kinematic and kinetic parameters between the techniques for each contact limb. The main findings highlighted that in both the RO techniques, the second contact limb wrist joint is exposed to higher mechanical loads than the first contact limb demonstrated by increased axial compression force and loading rate. In the parallel technique, the second contact limb wrist joint is exposed to higher axial compression load. Differences between wrist joint kinetics highlight that the T-shape technique may potentially lead to reducing these bio-physical loads and consequently protect the second contact limb wrist joint from overload and biological failure. Highlighting the biomechanical risk factors facilitates the process of technique selection making more objective and safe. 相似文献
3.
Roman Farana Daniel Jandacka Jaroslav Uchytil David Zahradnik Gareth Irwin 《Sports biomechanics / International Society of Biomechanics in Sports》2014,13(2):123-134
Chronic elbow injuries from tumbling in female gymnastics present a serious problem for performers. This research examined how the biomechanical characteristics of impact loading and elbow kinematics and kinetics change as a function of technique selection. Seven international-level female gymnasts performed 10 trials of the round-off from a hurdle step to flic-flac with ‘parallel’ and ‘T-shape’ hand positions. Synchronized kinematic (3D-automated motion analysis system; 247 Hz) and kinetic (two force plates; 1,235 Hz) data were collected for each trial. Wilcoxon non-parametric test and effect-size statistics determined differences between the hand positions examined in this study. Significant differences (p < 0.05) and large effect sizes (ES>0.8) were observed for peak vertical ground reaction force (GRF), anterior–posterior GRF, resultant GRF, loading rates of these forces and elbow joint angles, and internal moments of force in sagittal, transverse, and frontal planes. In conclusion, the T-shape hand position reduces vertical, anterior–posterior, and resultant contact forces and has a decreased loading rate indicating a safer technique for the round-off. Significant differences observed in joint elbow moments highlighted that the T-shape position may prevent overloading of the joint complex and consequently reduce the potential for elbow injury. 相似文献
4.
The purpose of the study was to examine the vertical ground reaction force component when approaching the gait transition point from either a walk-to-run or run-to-walk perspective. The vertical ground reaction forces (VGRF) of five steps before gait transitions for both walk-to-run and run-to-walk were collected on a motor driven treadmill with embedded force plates. Transition specific characteristics of the VGRF were observed for both types of gait transition. Running peak force and time to peak force reduced dramatically in a quadratic fashion as approaching to the run-to-walk transition. The walking VGRF first peak increased linearly, and the second peak decreased quadratically prior to walk-to-run transition. Walking VGRF appearing to be more sensitive to acceleration than the running VGRF. 相似文献
5.
The penalty throw in water polo: a cinematographic analysis 总被引：1，自引：0，他引：1
Three-dimensional (3-D) high-speed cinematography was used to record the penalty throw in water polo by six elite male (M) and six elite female (F) players. The direct linear transformation technique (DLT) was used in the 3-D space reconstruction from 2-D images recorded via laterally placed phase-locked cameras operating at 200 Hz. Five of the twelve subjects lifted the ball from underneath at the start of the throw whilst the remaining subjects opted for a rotation lift. As the ball was brought behind the head the females used very little hip and shoulder rotation compared to the male players so that four of the six female subjects were square on to the target at the rear point. At the completion of the backswing the wrist was flexed to a similar angle (M-162 degrees; F-158 degrees); the elbow angle showed significantly greater flexion for females (85 degrees) than males (107 degrees). During the forward swing, from rear point to release, the wrist joint of the female players flexed from a rear point angle of 158 degrees to 148 degrees at release. The wrist movement for male subjects was different from the females in that it flexed from 162 degrees to 147 degrees, 0.10 s prior to release and then extended to 159 degrees at palmar release before again flexing to 156 degrees at release. The amount of elbow extension during the forward swing was 48 degrees for both groups; however, the females actually released the ball with the forearm vertical (89 degrees) compared to the male forearm angle of 78 degrees. Maximum angular velocity of the wrist and elbow occurred at release for 9 of the 12 subjects. Both the wrist and elbow joints (F-148 degrees; M-156 degrees at wrist and F-126 degrees; M-148 degrees at elbow) demonstrated greater flexion at release in female subjects, compared with males. Maximum linear endpoint velocities for the forearm and hand segments occurred at ball release resulting in mean ball velocities of 19.1 m s-1 and 14.7 m s-1 for male and female subjects respectively. 相似文献
6.
David Zahradnik Daniel Jandacka Gabriela Beinhauerova Joseph Hamill 《Journal of sports sciences》2020,38(20):2367-2373
ABSTRACT The lateral tilt of the arms accompanied by trunk lateral tilt is a typical blocking manoeuvre in volleyball. However, during this unanticipated blocking movement, an associated risk of ACL injury may result. The aim of the present study was to compare associative ACL risk factors at the initial contact and the first and second peak of VGRF during an unanticipated blocking movement with different arm positions. Synchronized kinematic and kinetic data were collected for each trial of each condition. Student paired t-tests and effect size were used to determine differences between two conditions (S – with arms straight up from the body) and (T – with the arms and trunk laterally tilted). The results showed that the T condition significantly decreases knee flexion, increases VGRF at the foot contact, first peak force and increases the valgus moment at the first peak force. The values of the associated risk factors for a non-contact ACL injury appear to be related to the tilted arm position accompanied by trunk tilt towards to right lower limb during landing. The players should be taught to land with greater knee flexion and, if possible, a double-leg landing to decrease right lower limb loading during the blocking manoeuvre. 相似文献
7.
Bradshaw EJ Le Rossignol P 《Sports biomechanics / International Society of Biomechanics in Sports》2004,3(2):249-262
The aim of this study was to identify the anthropometric and physical prerequisites for high difficulty floor tumbling and vaulting. Twenty 8-14 year old female talent-selected gymnasts performed handstand push-offs, and single and multiple jumps on a portable Kistler force plate. The force curves were analysed using Kistler and Excel software to obtain peak displacement, peak take-off force, and power The gymnasts were also assessed for sprinting, with and without vaulting, and standing broad jump performances. Video footage from the vault take-off was analysed using Video Expert II software to obtain the horizontal and vertical take-off velocities. Each gymnast's best vault starting score, three best floor tumbling skills, and anthropometric characteristics were recorded. Statistical analysis included one-way analysis of variance (ANOVA) to examine the effect of age (8-10 years, 11-12 years, 13-14 years) on the performance measures and linear regression analysis with performance start score for vault or best floor tumbling score as the outcome variable. The best regression model for indicating vaulting talent had, as predictor variables, resultant velocity at take-off from the board, squat jump power, and average power during the last five jumps in the continuous bent-leg jump series. The best regression model for indicating floor tumbling ability had, as predictor variables, age, vault running velocity, and reduced ground contact time in a handstand push-off. 相似文献
8.
Three‐dimensional (3‐D) high‐speed cinematography was used to record the penalty throw in water polo by six elite male (M) and six elite female (F) players. The direct linear transformation technique (DLT) was used in the 3‐D space reconstruction from 2‐D images recorded via laterally placed phase‐locked cameras operating at 200 Hz. Five of the twelve subjects lifted the ball from underneath at the start of the throw whilst the remaining subjects opted for a rotation lift. As the ball was brought behind the head the females used very little hip and shoulder rotation compared to the male players so that four of the six female subjects were square on to the target at the rear point. At the completion of the backswing the wrist was flexed to a similar angle (M‐162°; F‐158°); the elbow angle showed significantly greater flexion for females (85°) than males (107°). During the forward swing, from rear point to release, the wrist joint of the female players flexed from a rear point angle of 158° to 148° at release. The wrist movement for male subjects was different from the females in that it flexed from 162° to 147°, 0.10 s prior to release and then extended to 159° at palmar release before again flexing to 156° at release. The amount of elbow extension during the forward swing was 48° for both groups; however, the females actually released the ball with the forearm vertical (89°) compared to the male forearm angle of 78°. Maximum angular velocity of the wrist and elbow occurred at release for 9 of the 12 subjects. Both the wrist and elbow joints (F‐148°; M‐156° at wrist and F‐126°; M‐148° at elbow) demonstrated greater flexion at release in female subjects, compared with males. Maximum linear endpoint velocities for the forearm and hand segments occurred at ball release resulting in mean ball velocities of 19.1 m s ‐1 and 14.7 m s‐ 1 for male and female subjects respectively. 相似文献
9.
李克 《沈阳体育学院学报》2012,31(2):109-111
为了指明羽毛球和网球高压球技术动作的差异性,为羽毛球和网球教学和训练提供定量的科学依据,使用三维立体摄影解析法获取羽毛球和网球高压球技术动作的运动学参数,并对数据进行统计学处理。研究结果表明:在蹬地击球过程中,大腿、小腿和足的运动顺序为大关节带动小关节;在整个击打过程中,肩、肘、腕三关节移动速度基本保持同步,肩关节角速度峰值最先出现,肘关节和腕关节角速度峰值出现时间基本同步;网球采用"棍打"的击球用力方式为主击球,羽毛球采用"鞭打"的击球用力方式为主击球。 相似文献
10.
The performance of the ice hockey slap and wrist shots: the effects of stick construction and player skill 总被引：1，自引：0，他引：1
The purpose of this study was to examine the interaction of players’ skill level, body strength, and sticks of various construction
and stiffness on the performance of the slap and wrist shots in ice hockey. Twenty male and twenty female subjects were tested.
Ten of each gender group were considered skilled and ten unskilled. In addition to general strength tests, each subject performed
the slap and wrist shots with three stick shafts of different construction and stiffness. Shot mechanics were evaluated by
simultaneously recording ground reaction forces from a force plate, stick movement and bending from high speed filming and
peak puck velocity from a radar gun. Data were analysed with a 4-way repeated measures ANOVA for several dependent variables
including peak puck velocity, peak Z (vertical) force, peak bending and stick to ground angles, peak angular deflection of
the shaft, and hand placement on the stick. The results indicated that: 1) the slap shot was much faster than the wrist shot
corresponding to greater vertical loading force, stick bending, and greater width of the hand placement; 2) the puck velocity
was influenced by skill level and body strength but not stick type; and, 3) that skilled players were able to generate more
vertical force and bend of the stick, in part, by adjusting their hand positions on the stick. Further studies are needed
to address the specific influence of body strength and skill on the techniques of these shots and in relation to stick material
and construction properties. 相似文献
11.
Allana Slater Anne Smith Leon Straker 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(1):45-56
High impact forces during gymnastic landings are thought to contribute to the high rate of injuries. Lower limb joint flexion is currently limited within gymnastic rules, yet might be an avenue for reduced force absorption. This study investigated whether lower limb flexion during three gymnastic landings was related to force. Differences between landings were also explored. Twenty-one elite women's artistic gymnasts performed three common gymnastic techniques: drop landing (DL), front and back somersaults. Ankle, knee, and hip angles, and vertical ground reaction force [(vGRF) magnitude and time to peak], were measured using three-dimensional motion analysis and force platform. The DL had significantly smaller peak vGRF, greater time to peak vGRF and larger lower limb flexion ranges than landing from either somersault. Peak vGRF and time to peak vGRF were inversely related. Peak vGRF was significantly reduced in gymnasts who landed with greater hip flexion, and time to peak was significantly increased with increasing ankle, knee, and hip flexion. Increased range of lower limb flexion should be encouraged during gymnastic landings to increase time to peak vGRF and reduce high impact force. For this purpose, judging criteria limitations on lower limb flexion should be reconsidered. 相似文献
12.
Tennis coaches often use the fundamental throwing skill as a training tool to develop the service action. However, recent skill acquisition literature questions the efficacy of non-specific training drills for developing complex sporting movements. Thus, this study examined the mechanical analogy of the throw and the tennis serve at three different levels of development. A 500 Hz, 22-camera VICON MX motion capture system recorded 28 elite female tennis players (prepubescent (n = 10), pubescent (n = 10), adult (n = 8)) as they performed flat serves and overhand throws. Two-way ANOVAs with repeated measures and partial correlations (controlling for group) assessed the strength and nature of the mechanical associations between the tasks. Preparatory mechanics were similar between the two tasks, while during propulsion, peak trunk twist and elbow extension velocities were significantly higher in the throw, yet the peak shoulder internal rotation and wrist flexion angular velocities were significantly greater in the serve. Furthermore, all of these peak angular velocities occurred significantly earlier in the serve. Ultimately, although the throw may help to prime transverse trunk kinematics in the serve, mechanics in the two skills appear less similar than many coaches seem to believe. Practitioners should, therefore, be aware that the throw appears less useful for priming the specific arm kinematics and temporal phasing that typifies the tennis serve. 相似文献
13.
Taylour J. Hinshaw Daniel J. Davis Jacob S. Layer Margaret A. Wilson Qin Zhu 《Journal of sports sciences》2019,37(4):414-423
Increased lateral trunk bending to the injured side has been observed when ACL injuries occur. The purpose was to quantify the effect of mid-flight lateral trunk bending on center of mass (COM) positions and subsequent landing mechanics during a jump-landing task. Forty-one recreational athletes performed a jump-landing task with or without mid-flight lateral trunk bending. When the left and right trunk bending conditions were compared with the no trunk bending condition, participants moved the COM of the upper body to the bending direction, while the COM of the pelvis, ipsilateral leg, and contralateral leg moved away from the bending direction relative to the whole body COM. Participants demonstrated increased peak vertical ground reaction forces (VGRF) and knee valgus and internal rotation angles at peak VGRF for the ipsilateral leg, but decreased peak VGRF and knee internal rotation angles at peak VGRF and increased knee varus angles at peak VGRF for the contralateral leg. Mid-flight lateral trunk resulted in an asymmetric landing pattern associated with increased ACL loading for the ipsilateral leg. The findings may help to understand altered trunk motion during ACL injury events and the discrepancy in ACL injuries related to limb dominance in badminton and volleyball. 相似文献
14.
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
15.
为了解我国少年体操运动员关节损伤状况并制定预防措施,为教练员科学制定训练计划提供理论依据,采用调查访问法、数理统计法、专家访谈法、文献资料法等方法对参加2008年全国少年儿童体操比赛的122名运动员进行了调查分析,结果显示损伤部位主要集中在足部、踝关节、膝关节、肘关节、腕关节、坐骨结节、股骨头等部位,且大多数为慢性劳损.为预防各种关节损伤,应加强训练中的医务监督,并根据运动员损伤特点合理调整训练计划. 相似文献
16.
17.
Gennaro Boccia Davide Dardanello Cantor Tarperi Luca Festa Antonio La Torre Barbara Pellegrini 《European Journal of Sport Science》2018,18(5):695-704
Women are known to be less fatigable than men in single-joint exercises, but fatigue induced by running has not been well understood. Here we investigated sex differences in central and peripheral fatigue and in rate of force development (RFD) in the knee extensors after a half-marathon run. Ten male and eight female amateur runners (aged 25–50 years) were evaluated before and immediately after a half-marathon race. Knee extensors forces were obtained under voluntary and electrically evoked isometric contractions. Maximal voluntary isometric contraction (MVC) force and peak RFD were recorded. Electrically doublet stimuli were delivered during the MVC and at rest to calculate the level of voluntary activation and the resting doublet twitch. After the race, decreases in MVC force (males: ?11%, effect size [ES] 0.52; females: ?11% ES 0.33), voluntary activation (males: ?6%, ES 0.87; females: ?4%, ES 0.72), and resting doublet twitch (males: ?6%, ES 0.34; females: ?8%, ES 0.30) were found to be similar between males and females. The decrease in peak RFD was found to be similar between males and females (males: ?14%, ES 0.43; females: ?15%, ES 0.14). Half-marathon run induced both central and peripheral fatigue, without any difference between men and women. The maximal and explosive strength loss was found similar between sexes. Together, these findings do not support the need of sex-specific training interventions to increase the tolerance to neuromuscular fatigue in half-marathoners. 相似文献
18.
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
19.
Asymmetry in gymnastics underpins successful performance and may also have implications as an injury mechanism; therefore, understanding of this concept could be useful for coaches and clinicians. The aim of this study was to examine kinematic and external kinetic asymmetry of the arm segments during the contact phase of a fundamental skill, the forward handspring on floor. Using a repeated single subject design six female National elite gymnasts (age: 19?±?1.5 years, mass: 58.64?±?3.72?kg, height: 1.62?±?0.41?m), each performed 15 forward handsprings, synchronised 3D kinematic and kinetic data were collected. Asymmetry between the lead and non-lead side arms was quantified during each trial. Significant kinetic asymmetry was observed for all gymnasts (p?相似文献
20.
Blanksby B Skender S Elliott B McElroy K Landers G 《Sports biomechanics / International Society of Biomechanics in Sports》2004,3(1):1-14
Kinetic (3-D force plate), kinematic (videography) and temporal characteristics of backstroke turns by 20 male and 16 female swimmers were recorded to identify and describe key elements of backstroke turning performance. Data were recorded during a 50 m maximum effort swim in a 25 metre pool. A Pearson product moment correlation matrix revealed that the 5 m RTT was significantly correlated with anthropometric measures of height, mass, trochanteric height and age; kinetic measures of horizontal impulse and peak force; and kinematic measures of wall contact time and peak velocity. The stepwise multiple regression equation to predict 5 m RTT was: 19.6-0.75 trochanteric height-1.8 wall exit velocity-0.03 peak vertical force. Four key factors were identified from a principle components factor analysis--anthropometry and force, post-turn velocity, force preparation and rotational skills. Implications from the findings were that age-group backstrokers should 'hit the wall hard' with relatively extended legs to reduce swim distance and push-off deceleration; use minimal wall contact time, and maximise forces to develop high horizontal velocities in a streamlined position. 相似文献