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1.
While 10% of the general population is left-handed, 27% of professional baseball pitchers are left-handed. Biomechanical differences between left- and right-handed college pitchers have been previously reported, but these differences have yet to be examined at the professional level. Therefore, the purpose of this study was to compare pitching biomechanics between left- and right-handed professional pitchers. It was hypothesised that there would be significant kinematic and kinetic differences between these two groups. Pitching biomechanics were collected on 96 left-handed pitchers and a group of 96 right-handed pitchers matched for age, height, mass and ball velocity. Student t-tests were used to identify kinematic and kinetic differences (p < 0.05). Of the 31 variables tested, only four were found to be significantly different between the groups. Landing position of the stride foot, trunk separation at foot contact, maximum shoulder external rotation and trunk forward tilt at ball release were all significantly greater in right-handed pitchers. The magnitude of the statistical differences found were small and not consistent with differences in the two previous, smaller studies. Thus, the differences found may be of minimal practical significance and mechanics can be taught the same to all pitchers, regardless of throwing hand.  相似文献   

2.
Controversy continues whether curveballs are stressful for young baseball pitchers. Furthermore, it is unproven whether professional baseball pitchers have fewer kinematic differences between fastballs and off-speed pitches than lower level pitchers. Kinematic and kinetic data were measured for 111 healthy baseball pitchers (26 youth, 21 high school, 20 collegiate, 26 minor league, and 18 major league level) throwing fastballs, curveballs, and change-ups in an indoor biomechanics laboratory with a high-speed, automated digitising system. Differences between pitch types and between competition levels were analysed with repeated measures ANOVA. Shoulder and elbow kinetics were greater in fastballs than in change-ups, while curveball kinetics were not different from the other two types of pitches. Kinematic angles at the instant of ball release varied between pitch types, while kinematic angles at the instant of lead foot contact varied between competition levels. There were no significant interactions between pitch type and competition level, meaning that kinetic and kinematic differences between pitch types did not vary by competition level. Like previous investigations, this study did not support the theory that curveballs are relatively more stressful for young pitchers. Although pitchers desire consistent kinematics, there were differences between pitch types, independent of competition level.  相似文献   

3.
The purpose of this study was to quantify and compare kinematic, temporal, and kinetic characteristics of American and Korean professional pitchers in order to investigate differences in pitching mechanics, performance, and injury risks among two different cultures and populations of baseball pitchers. Eleven American and eight Korean healthy professional baseball pitchers threw multiple fastball pitches off an indoor throwing mound positioned at regulation distance from home plate. A Motion Analysis three-dimensional automatic digitizing system was used to collect 200 Hz video data from four electronically synchronized cameras. Twenty kinematic, six temporal, and 11 kinetic variables were analyzed at lead foot contact, during the arm cocking and arm acceleration phases, at ball release, and during the arm deceleration phase. A radar gun was used to quantify ball velocity. At lead foot contact, the American pitchers had significantly greater horizontal abduction of the throwing shoulder, while Korean pitchers exhibited significantly greater abduction and external rotation of the throwing shoulder. During arm cocking, the American pitchers displayed significantly greater maximum shoulder external rotation and maximum pelvis angular velocity. At the instant of ball release, the American pitchers had significantly greater forward trunk tilt and ball velocity and significantly less knee flexion, which help explain why the American pitchers had 10% greater ball velocity compared to the Korean pitchers. The American pitchers had significantly greater maximum shoulder internal rotation torque and maximum elbow varus torque during arm cocking, significantly greater elbow flexion torque during arm acceleration, and significantly greater shoulder and elbow proximal forces during arm deceleration. While greater shoulder and elbow forces and torques generated in the American pitchers helped generate greater ball velocity for the American group, these greater kinetics may predispose this group to a higher risk of shoulder and elbow injuries.  相似文献   

4.
Baseball     
The purpose of this study was to quantify and compare kinematic, temporal, and kinetic characteristics of American and Korean professional pitchers in order to investigate differences in pitching mechanics, performance, and injury risks among two different cultures and populations of baseball pitchers. Eleven American and eight Korean healthy professional baseball pitchers threw multiple fastball pitches off an indoor throwing mound positioned at regulation distance from home plate. A Motion Analysis three‐dimensional automatic digitizing system was used to collect 200 Hz video data from four electronically synchronized cameras. Twenty kinematic, six temporal, and 11 kinetic variables were analyzed at lead foot contact, during the arm cocking and arm acceleration phases, at ball release, and during the arm deceleration phase. A radar gun was used to quantify ball velocity. At lead foot contact, the American pitchers had significantly greater horizontal abduction of the throwing shoulder, while Korean pitchers exhibited significantly greater abduction and external rotation of the throwing shoulder. During arm cocking, the American pitchers displayed significantly greater maximum shoulder external rotation and maximum pelvis angular velocity. At the instant of ball release, the American pitchers had significantly greater forward trunk tilt and ball velocity and significantly less knee flexion, which help explain why the American pitchers had 10% greater ball velocity compared to the Korean pitchers. The American pitchers had significantly greater maximum shoulder internal rotation torque and maximum elbow varus torque during arm cocking, significantly greater elbow flexion torque during arm acceleration, and significantly greater shoulder and elbow proximal forces during arm deceleration. While greater shoulder and elbow forces and torques generated in the American pitchers helped generate greater ball velocity for the American group, these greater kinetics may predispose this group to a higher risk of shoulder and elbow injuries.  相似文献   

5.
为进一步明确影响棒球投手投球速度的关键因素,通过中国知网、Web of Science和PubMed等平台以棒球投手、投球速度、运动生物力学和鞭打动作等为关键词,检索并整理归纳20世纪90年代至今的相关文献资料。通过对比国内外优秀棒球投手投球速度和专项技术能力,发现投球时投掷臂肩关节外旋角度、肩关节水平外展角度、肘关节角度、躯干前倾幅度、前腿膝关节角度等运动学指标,投掷臂各环节受力峰值、前腿受到的最大地面反作用力等动力学指标均对投球速度起关键性影响作用。教练员和棒球投手可通过改善上下肢关节角度和角速度等指标参数的大小、增强肌肉力量和柔韧性等手段,完善投手投球技术动作,提高投球速度。  相似文献   

6.
According to recent motor control studies, it is important to know probabilistic structure of his/her own motor errors to choose an optimal motor plan (i.e., where you aim at) to maximise the expected gain. In this study, we questioned if pitching form determines the probabilistic structure of pitching errors in baseball pitchers. Eighteen collegiate baseball pitchers with various pitching forms including right- and left-handed overarm, sidearm and underarm throwers threw 100 pitches aiming at a target located 90 cm above the ground. Two dimensional distribution of pitch location was fitted by using bivariate normal distribution and 95% confidence ellipse was calculated. In order to quantify the pitching form, the direction of the throwing arm trajectory in frontal plane was calculated. The direction of the long axis was dependent on each participant’s pitching form (e.g., right overarm pitchers pitched along a right-up–left-down ellipse and left overarm pitchers pitched along a left-up–right-down ellipse). This was confirmed by circular correlation analysis (P = 0.98). These results suggest that different mechanisms, potentially errors in pitching mechanics and errors in ball release timing, might contribute to errors along the long axis and those along the short axis.  相似文献   

7.
The aim of this study was to compare and evaluate the kinematics of baseball pitchers who participated in the 1996 XXVI Centennial Olympic Games. Two synchronized video cameras operating at 120 Hz were used to video 48 pitchers from Australia, Japan, the Netherlands, Cuba, Italy, Korea, Nicaragua and the USA. All pitchers were analysed while throwing the fastball pitch. Twenty-one kinematic parameters were measured at lead foot contact, during the arm cocking and arm acceleration phases, and at the instant of ball release. These parameters included stride length, foot angle and foot placement; shoulder abduction, shoulder horizontal adduction and shoulder external rotation; knee and elbow flexion; upper torso, shoulder internal rotation and elbow extension angular velocities; forward and lateral trunk tilt; and ball speed. A one-way analysis of variance (P ? 0.01) was used to assess kinematic differences. Shoulder horizontal adduction and shoulder external rotation at lead foot contact and ball speed at the instant of ball release were significantly different among countries. The greater shoulder horizontal abduction observed in Cuban pitchers at lead foot contact is thought to be an important factor in the generation of force throughout the arm cocking and arm acceleration phases, and may in part explain why Cuban pitchers generated the greatest ball release speed. We conclude that pitching kinematics are similar among baseball pitchers from different countries.  相似文献   

8.
Kinematic comparisons of 1996 Olympic baseball pitchers   总被引：1，自引：0，他引：1  
The aim of this study was to compare and evaluate the kinematics of baseball pitchers who participated in the 1996 XXVI Centennial Olympic Games. Two synchronized video cameras operating at 120 Hz were used to video 48 pitchers from Australia, Japan, the Netherlands, Cuba, Italy, Korea, Nicaragua and the USA. All pitchers were analysed while throwing the fastball pitch. Twenty-one kinematic parameters were measured at lead foot contact, during the arm cocking and arm acceleration phases, and at the instant of ball release. These parameters included stride length, foot angle and foot placement; shoulder abduction, shoulder horizontal adduction and shoulder external rotation; knee and elbow flexion; upper torso, shoulder internal rotation and elbow extension angular velocities; forward and lateral trunk tilt; and ball speed. A one-way analysis of variance (P < 0.01) was used to assess kinematic differences. Shoulder horizontal adduction and shoulder external rotation at lead foot contact and ball speed at the instant of ball release were significantly different among countries. The greater shoulder horizontal abduction observed in Cuban pitchers at lead foot contact is thought to be an important factor in the generation of force throughout the arm cocking and arm acceleration phases, and may in part explain why Cuban pitchers generated the greatest ball release speed. We conclude that pitching kinematics are similar among baseball pitchers from different countries.  相似文献   

9.
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10.
棒球投手肩关节旋转运动特征研究   总被引：4，自引：0，他引：4  
棒球比赛中,投手是一支球队的灵魂,在很大程度上决定全局的比赛。肩部力量素质和活动范围是投手有效投球的基础,在很大程度上决定投球技术、机能的发挥。肩关节既是躯干和上肢的连结点,又是上肢运动的支点,是保证上肢完成三维活动的重要结构[1]。因此,肩关节在棒球运动中发挥着  相似文献   

11.
The aim of this study was to provide an in-depth analysis of the pick-off play in baseball. Ten collegiate left-handed pitchers and nine base-runners participated in this study. The pitchers were videotaped with four cameras to derive three-dimensional data while performing deliveries in the directions of first base and home plate in a laboratory setting. Deliveries were performed from flat ground. Differences between these deliveries were measured through ten selected joint and segment angles. The base-runners completed two distinct procedures in which they viewed video footage of left-handed pitchers and estimated the intended delivery direction. Base-runners were subsequently interviewed to determine the reasoning behind their decisions. The pitchers' data revealed differences between delivery types in nearly all of the selected angles (P < 0.01). The base-runners' data demonstrated that their ability to discriminate delivery types improved when allowed more viewing time per trial (P < 0.01). Additionally, commonalities exist among the base-runners' focal points on the pitcher while making decisions regarding delivery direction and the kinematic differences between deliveries in left-handed pitchers. The practical significance of these results, however, may be more difficult to interpret.  相似文献   

12.
The aim of this study was to provide an in-depth analysis of the pick-off play in baseball. Ten collegiate left-handed pitchers and nine base-runners participated in this study. The pitchers were videotaped with four cameras to derive three-dimensional data while performing deliveries in the directions of first base and home plate in a laboratory setting. Deliveries were performed from flat ground. Differences between these deliveries were measured through ten selected joint and segment angles. The base-runners completed two distinct procedures in which they viewed video footage of left-handed pitchers and estimated the intended delivery direction. Base-runners were subsequently interviewed to determine the reasoning behind their decisions. The pitchers' data revealed differences between delivery types in nearly all of the selected angles (P < 0.01). The base-runners' data demonstrated that their ability to discriminate delivery types improved when allowed more viewing time per trial (P < 0.01). Additionally, commonalities exist among the base-runners' focal points on the pitcher while making decisions regarding delivery direction and the kinematic differences between deliveries in left-handed pitchers. The practical significance of these results, however, may be more difficult to interpret.  相似文献   

13.
In this study we compared the kinematic features of the throwing motion between young baseball players of different age groups. Forty-four Japanese baseball players aged 6.1 to 12.3 years who regularly played baseball, including pitchers and position players, had their throwing actions analyzed three-dimensionally using high speed videography. Of this sample, 26 players aged above 9 years of age were categorized as the senior group, while the remaining 18 were categorized as the junior group. Senior group throwers had greater height and body mass, and produced a greater ball speed than junior group throwers. The throwing arm movement of senior group throwers was similar to that of adult skilled players. However, in the junior group throwers, the shoulder horizontal adduction angle was larger during the arm acceleration phase, and the maximum angular velocities of elbow extension and shoulder internal rotation occurred later than in senior group throwers. These results indicate that players aged above 9 years can acquire a mature throwing arm movement, while players younger than that will use an immature motion. A possible reason why these differences were shown is that the official baseball is relatively heavy for junior group throwers; they would be better advised to use a lighter ball in throwing practice.  相似文献   

14.
Some studies have reported that overarm baseball pitching shows a proximal to distal sequential joint motion including a rapid extension of the elbow. It has been suggested that the rapid elbow extension just before ball release is not due to the action of the elbow extensor muscles, but the underlying mechanisms are not so clear. The purpose of this study was to determine the contributions of each joint muscular- and motion-dependent torques, including the upper trunk and throwing arm joints to generate the rapid elbow extension during baseball pitching. The right handed throwing motions of three baseball pitchers were recorded using five high-speed video cameras and the positional data were calculated using the direct linear transformation method. A throwing arm dynamic model of the upper trunk and throwing arm joints was then used, including 10 degrees of freedom, to calculate the throwing arm joint muscular-, throwing arm and upper trunk joint motion-, gravity-, and external force-dependent components that contribute to the maximum elbow extension angular velocity. The results showed that the rapid elbow extension was primarily due to the upper trunk counterclockwise rotation and shoulder horizontal adduction angular velocity-dependent torques. This study implied that the trunk counterclockwise rotators and shoulder horizontal adductors generate positive torques to maintain the angular velocities of the upper trunk counterclockwise rotation and shoulder horizontal adduction may play a key role in producing the rapid elbow extension.  相似文献   

15.
The purpose of this study was to determine how often flaws in pitching mechanics identified from biomechanical analysis are corrected. The biomechanics of 46 baseball pitchers were evaluated twice, with an average of 12 months (range 2–48 months) between evaluations. Pitchers were healthy at the time of both evaluations, competing at the high school, college, minor league or Major League level. After warming up, each participant pitched 10 full-effort fastballs. Automated three-dimensional motion analysis was used to compute eight kinematic parameters which were compared with a database of elite professional pitchers. Flaws—defined as deviations from the elite range—were explained to each participant or coach after his initial evaluation. Data from the second evaluation revealed that 44% of all flaws had been corrected. Flaws at the instant of foot contact (stride length, front foot position, shoulder external rotation, shoulder abduction, elbow flexion) or slightly after foot contact (time between pelvis rotation and upper trunk rotation) seemed to be corrected more often than flaws near the time of ball release (knee extension and shoulder abduction). Future research may determine which level athletes or which training methods are most effective for correcting flaws.  相似文献   

16.
Abstract

In this study we compared the kinematic features of the throwing motion between young baseball players of different age groups. Forty‐four Japanese baseball players aged 6.1 to 12.3 years who regularly played baseball, including pitchers and position players, had their throwing actions analyzed three‐dimensionally using high speed videography. Of this sample, 26 players aged above 9 years of age were categorized as the senior group, while the remaining 18 were categorized as the junior group. Senior group throwers had greater height and body mass, and produced a greater ball speed than junior group throwers. The throwing arm movement of senior group throwers was similar to that of adult skilled players. However, in the junior group throwers, the shoulder horizontal adduction angle was larger during the arm acceleration phase, and the maximum angular velocities of elbow extension and shoulder internal rotation occurred later than in senior group throwers. These results indicate that players aged above 9 years can acquire a mature throwing arm movement, while players younger than that will use an immature motion. A possible reason why these differences were shown is that the official baseball is relatively heavy for junior group throwers; they would be better advised to use a lighter ball in throwing practice.  相似文献   

17.
This study investigated the contribution of flexor muscles to the forearm through fatigue; therefore, the differences in forearm mechanisms on the pitching motion in fastball were analysed. Fifteen baseball pitchers were included in this study. Ultrasonographical examination of participants’ ulnar nerve in the cubital tunnel with the elbow extended and at 45°, 90° and 120° of flexion was carried. A three-dimensional motion analysis system with 14 reflective markers attached on participants was used for motion data collection. The electromyography system was applied over the flexor carpi ulnaris, flexor carpi radialis and extensor carpi radialis muscles of the dominant arm. Flexor carpi ulnaris muscle activity showed a significant difference during the acceleration phase, with a peak value during fastball post-fatigue (P = 0.02). Significant differences in the distance between ulnar nerve and medial condyle on throwing arm and non-throwing arm were observed as the distance increased with the elbow movement from 0° to 120° of flexion (P = 0.01). The significant increase of the flexor carpi ulnaris muscle activity might be responsible for maintaining the stability of the wrist joint. The increased diameter might compress the ulnar nerve and cause several pathological changes. Therefore, fatigue in baseball pitchers still poses a threat to the ulnar nerve because the flexor carpi ulnaris and flexor carpi radialis all originate from the medial side of the elbow, and the swelling tendons after fatigue might be a key point.  相似文献   

18.
ABSTRACT

This study aimed to describe stationary overhead throwing biomechanics in South African cricketers, considering playing level, and relative to baseball. Kinematics and ground reaction forces were collected during throwing trials. Inverse dynamics was used to calculate joint kinetics. Inter-subject variability was calculated using the coefficient of variance. A one-dimensional statistical parametric mapping ANOVA was conducted to assess differences between the kinematic waveforms in elite and amateur cricketers (p < 0.05). Fifteen cricketers (elite = 8; amateur = 7) participated in this study. The basic parameters of a cricketer’s throwing action are described. Substantial inter-subject variability was noted for all variables, except lumbopelvic movement. Cricketers presented with 74.9 ± 27.3° glenohumeral external rotation and 94.8 ± 23.7° elbow flexion, at maximum external rotation (MER). Amateur cricketers displayed decreased elbow flexion range of motion between 2-14% of the throwing cycle (F = 9.365;p = 0.01); greater shoulder (121.0vs85.9 N; F = 0.36,p = 0.021) and elbow compression (105.6vs72.8 N;F = 0.007,p = 0.043), and superior shoulder force (203.1vs115.5 N;F = 2.43,p = 0.022) at MER, when compared with elite cricketers. Cricketers display similarities to baseball pitchers when throwing overhead from a stationary position. The “preparatory arc” utilised is different to the wind-up noted for baseball. The forces exerted on the shoulder and elbow, in amateur cricketers specifically, are substantially greater at MER and may indicate the potential risk for injury.  相似文献   

19.
Because youth athletes are smaller and weaker than their adult counterparts, smaller equipment and fields are often used in youth sports. Previous research has shown that youth baseball pitchers use similar motions to older pitchers, but generate lower kinetics and angular velocities at the shoulder and elbow. The purpose of this study was to determine potential biomechanical benefits for youth pitchers to use lighter baseballs. Thirty-four youth (11.1 ± 0.7 years) pitchers pitched both standard [5 ounce (142 g)] and lightweight [4 ounce(113 g)] baseballs in a laboratory setting. Kinematic and kinetic parameters were measured with a six-camera high-speed motion analysis system. Three repeated measures MANOVAs were used to compare (p > 0.05) position, velocity, and kinetic parameters between the standard and lightweight baseballs. Subjective data were also collected. Pitching the lightweight ball produced no difference in arm position, but greater shoulder, elbow, and ball velocities. With the lightweight ball, pitchers produced decreased kinetics.Post-hoc analysis of the kinetic data revealed significant decreases in elbow varus torque and shoulder internal rotation torque. The data suggest that playing with lightweight baseballs may reduce the risk of overuse injury in the youth pitcher and also help develop arm speed. However, before introducing lightweight baseballs into the youth game, the effect of lighter, faster pitched balls for the batters and fielders should also be considered.  相似文献   

20.
Baseball pitching must be performed with correct technique if injuries are to be avoided and performance maximized. High-speed video analysis is accepted as the most accurate and objective method for evaluation of baseball pitching mechanics. The aim of this research was to develop an equivalent qualitative analysis method for use with standard video equipment. A qualitative analysis protocol (QAP) was developed for 24 kinematic variables identified as important to pitching performance. Twenty male baseball pitchers were videotaped using 60 Hz camcorders, and their technique evaluated using the QAP, by two independent raters. Each pitcher was also assessed using a 6-camera 200 Hz Motion Analysis system (MAS). Four QAP variables (22%) showed significant similarity with MAS results. Inter-rater reliability showed agreement on 33% of QAP variables. It was concluded that a complete and accurate profile of an athlete's pitching mechanics cannot be made using the QAP in its current form, but it is possible such simple forms of biomechanical analysis could yield accurate results before 3-D methods become obligatory.  相似文献   

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