A Comparison of Age Level on Baseball Hitting Kinematics

Abstract

We propose that learning proper hitting kinematics should be encouraged at a young age during youth baseball because this may help reinforce proper hitting kinematics as a player progresses to higher levels of baseball in their adult years. To enhance our understanding between youth and adult baseball hitting, kinematic and temporal analyses of baseball hitting were evaluated with a high-speed motion analysis system between 12 skilled youth and 12 skilled adult baseball players. There were only a small number of temporal differences between youth and adult hitters, with adult hitters taking significantly greater time than youth hitters during the stride phase and during the swing. Compared with youth hitters, adult hitters a) had significantly greater (p < .01) lead knee flexion when the hands started to move forward; b) flexed the lead knee over a greater range of motion during the transition phase (31° versus 13°); c) extended the lead knee over a greater range of motion during the bat acceleration phase (59° versus 32°); d) maintained a more open pelvis position at lead foot off ground; and e) maintained a more open upper torso position when the hands started to move forward and a more closed upper torso position at bat-ball contact. Moreover, adult hitters had greater peak upper torso angular velocity (857°/s versus 717°/s), peak left elbow extension angular velocity (752°/s versus 598°/s), peak left knee extension angular velocity (386°/s versus 303°/s), and bat linear velocity at bat-ball contact (30 m/s versus 25 m/s). The numerous differences in kinematic and temporal parameters between youth and adult hitters suggest that hitting mechanics are different between these two groups.

An Exploratory Biomechanical Analysis of the Side-to-Side Swing Patterns of Three Skilled Switch Hitters

“…Research findings support the notion that the baseball swing is an example of the kinetic link principle (Escamilla et al, 2009a;Shaffer et al, 1993;Szymanski & DeRenne, 2010;Welch et al, 1995). The kinetic link principle states that larger base segments transfer momentum to smaller adjacent body segments when the action is optimally performed.…”

“…The baseball swing has been examined empirically using kinematics and kinetics (Escamilla et al, 2009a;Katsumata, 2007;Welch, Banks, Cook & Draovitch, 1995), electromyography (Shaffer, Jobe, Pink & Perry, 1993) and physics (Cross, 2009). …”

“…Since the 1990's, three kinematic hitting studies have been conducted and have served to describe and define the baseball swing (Welch et al, 1995;Escamilla et al, 2009aEscamilla et al, & 2009b. Welch et al (1995) investigated the swing mechanics through kinematic and kinetic measures.…”

A Comparative Analysis of Biomechanical Factors and Premotor Time of Body Muscles between Elite College and Amateur Baseball Players during the Baseball Batting Motion

“…During the baseball batting motion, rotational movement that starts slowly in large segments at the early stage moves towards the point of impact where the bat meets the ball and leads to fast rotation by small segments. The momentum and speed of the bat is greatly affected by such sequential rotational velocity generated by the body segments (Escamilla et al, 2009;Welch et al, 1995). Therefore, the increase in the momentum and the speed of the bat attributed to rotational movement of the body during the batting motion is generated from cooperative contraction of the upper and lower body, and such contraction activities of the muscles also affect the sequential rotational movement of each segment.…”

“…Welch et al (1995) reported that in order to increase the bat speed during batting motion, the rotational movement of the pelvis and trunk must be in line with the rotational direction of the bat. Moreover, during the take back motion of the batting motion that prepares player to hit the ball, pelvic and trunk segments must be rotated on a vertical axis in counterclockwise direction, while in the phase when the bat is swung for impact, rotational movement in clockwise direction must be performed (Race, 1961;Escamilla et al, 2009). Rotational movement that starts lead foot to the target direction and quickly rotates the pelvis and trunk segments in counter-clockwise direction to perform the impact movement by moving the bat.…”