Knee Angle and Stride Length in Association with Ball Speed in Youth Baseball Pitchers
Bart van Trigt, Wouter Schallig, Erik van der Graaff, Marco Hoozemans, Dirkjan Veeger
The purpose of this study was to determine whether stride length and knee angle of the leading leg at foot contact, at the instant of maximal external rotation of the shoulder, and at ball release are associated with ball speed in elite youth baseball pitchers. In this study, fifty-two elite youth baseball pitchers (mean age 15.2 SD (standard deviation) 1.7 years) pitched ten fastballs. Data were collected with three high-speed video cameras at a frequency of 240 Hz. Stride length and knee angle of the leading leg were calculated at foot contact, maximal external rotation, and ball release. The associations between these kinematic variables and ball speed were separately determined using generalized estimating equations. Stride length as percentage of body height and knee angle at foot contact were not significantly associated with ball speed. However, knee angles at maximal external rotation and ball release were significantly associated with ball speed. Ball speed increased by 0.45 m/s (1 mph) with an increase in knee extension of 18 degrees at maximal external rotation and 19.5 degrees at ball release. In conclusion, more knee extension of the leading leg at maximal external rotation and ball release is associated with higher ball speeds in elite youth baseball pitchers.
full text: http://www.mdpi.com/2075-4663/6/2/51
Elite Athlete Motor and Loading Actions on The Upper Limb in Baseball Pitching
Xavier Gasparutto, Erik van der Graaff, Dirkjan Veeger
Keywords: pitching, baseball, joint loading, joint moment, elbow, shoulder
full text: https://www.sciencedirect.com/science/article/pii/S1877705816306579
The role of pelvis an thorax rotation velocity in baseball pitching.
The objective of the present study was to examine the relative timing of pelvis and thorax rotations in achieving high throwing velocities in baseball pitching. During the preseason, a kinematic analysis was performed on eight pitchers. Peak angular velocities of the pelvis and thorax were determined and separation, defined as the time between the moments of maximal rotation velocity of the pelvis and thorax, was calculated. By themselves, maximal pelvis and thorax rotation velocity were not associated with throwing velocity. Separation was positively and significantly associated with throwing velocity. Results indicate that the relative timing of pelvis and thorax peak rotation velocity in pitching fastballs in baseball is a determinant of throwing velocity in skilled pitchers.
Keywords: biomechanics; kinematics; performance; pitching; separation
full text: https://ojs.ub.uni-konstanz.de/cpa/article/view/6976
Longitudinal changes in shoulder ROM and strength in association with ball-throwing speed in elite youth baseball pitchers.
The purpose of this prospective study was to examine the longitudinal changes in shoulder ER ROM and relative IR strength in elite youth baseball pitchers over one year and to determine their associations with changes in ball speed for throwing fastballs. One hundred and five Dutch elite youth baseball pitchers were measured three times over a period of one year. Statistical analyses of the data revealed that changes in ER ROM and relative IR strength were not significantly associated with changes in ball-throwing speed.
Keywords: baseball; pitching; performance; screening; prospective study
full text: https://ojs.ub.uni-konstanz.de/cpa/article/view/7088
Shoulder joint velocity during fastball pitching baseball.
The purpose of this study was to assess the rotation and translation velocity of the shoulder complex during fastball pitching in baseball. 8 pitchers from the Dutch AAA team performed each 3 fastball pitches. Their motion was recorded by an opto-electronic device. Kinematic computation was performed using the quaternion algebra. The results showed that the endo-rotation, depression and backward rotation velocity of the humerus at ball release are initiated by a translation of the scapular girdle in the forward and upward direction before ball release.
Keywords: baseball; pitching; upper limb; shoulder; velocity
full text: https://ojs.ub.uni-konstanz.de/cpa/article/view/6550
Asymmetry and evolution over a one-year period of the upward rotation of the scapula in youth baseball pitchers
Erik van der Graaff , Bengt Kom, Femke van Dis, Xavier Gasparutto, Marco Hoozemans & Dirkjan Veeger
The pitching motion is an asymmetric action by which coordination of scapular rotation in the dominant arm might be affected in time and in comparison with the non-dominant arm. The study aimed to compare asymmetry and the evolution of scapular upward rotation over a one-year period. Data were collected twice, before and after a one-year period, from 92 participants (age = 15.1 SD 1.4 years, body height = 177.3 SD 10.9 cm, body weight 69.2 SD 14.5 kg). Scapular motion was tracked at different glenohumeral angles of elevation in the scapular plane: anatomical position (0°), 45°, 90° and 135°. Scapular upward rotation was calculated as the angle between the spinae scapula and the spine. Scapular upward rotation of the dominant arm was 5.1° (95% CI: 2.1°−8.1°) more compared to the non-dominant arm. Age group or glenohumeral angles of elevation did not affect this difference. Scapular upward rotation of the dominant arm decreased 1.9° (95% CI: −0.5° to 4.3°) after a one-year period, however, neither this observation, nor the interaction with age group or elevation angle was significant. These findings may indicate that pitchers could be at risk to develop shoulder injuries especially those that have been associated with scapular asymmetry.
full text: https://www.tandfonline.com/doi/full/10.1080/23335432.2018.1499441