Weighted Baseball Training Affects Arm Speed without Increasing Elbow and Shoulder Joint Kinetics

Abstract

Long-term training effects of weighted ball throwing programs have been well documented. However, the mechanisms by which these effects are facilitated are poorly understood due to the difficulty of measuring biomechanics in the baseball throwing motion. The purpose of this study is to replicate previous methods investigating within-session effects of throwing overload and underload baseballs to provide mechanistic evidence for weighted baseball training methods. We hypothesized that varying the pitched ball weight between three, four, five, six, and seven ounces will affect pitched ball velocity, upper body kinematics, lower body kinematics, kinematic velocities, and throwing arm joint kinetics during a maximum intent throwing workout. Twenty-six collegiate and professional level baseball pitchers ages 20-30 (mean age 23.5 ± 2.7 years) participated in a pitch velocity and biomechanical evaluation while pitching a series of leather weighted baseballs from a regulation pitching mound. A one-way repeated measures ANOVA was used to evaluate the within-subject effect of ball weight on a total of 15 parameters: pitch velocity, five kinematic positions, four kinematic velocities, and five kinetics. We found that as ball weight increased, pitch velocity, maximum elbow flexion, maximum pelvis rotation velocity, maximum shoulder internal rotation velocity, and maximum elbow extension velocity decreased, while anterior trunk tilt at ball release increased. Training with three- to seven-ounce baseballs can be used to work on increasing pitching velocity without increasing throwing arm joint kinetics or changing pitching mechanics in a practically significant way.

The effects of a four weeks combined resistance training programme on cricket bowling velocity

“…This study supports the hypothesis that a combined resistance training programme would increase ball release velocity in recreational cricket pace bowlers without a statistically significant decrease in bowling accuracy. In comparison with previous resistance training studies in other sports [ 9 , 11 ] , the significant 6% increase in ball release velocity in four weeks is one of the largest increases in ball release velocity reported for such a short period of time, even when training recreational (club) participants.…”

“…This study supports the hypothesis that a combined resistance training programme would increase ball release velocity in recreational cricket pace bowlers without a statistically significant decrease in bowling accuracy. In comparison with previous resistance training studies in other sports [9,11] , the…”

“…[ 10 ] The use of weighted implement training is a popular example and has shown to improve throwing velocity in baseball. [ 11 ] The theory behind the principles of overweight and underweight training can be derived from the force-velocity curve of movement, where resistance training occurs in the motion of the action performed. Training with overweight balls is based on the principle of an overload of force (enhancing strength), whereas training with underweighted balls is based on the principle of an overload of velocity (enhancing speed).…”