The Influence of Practice Design Using Task Constraints to Develop a Pitch With Vertical Break in Softball

Abstract

Groups of softball pitchers seeking to develop a movement pitch practiced under two different practice conditions. One group practiced using instructions centered on achieving an idealized movement pattern to create break on the ball (Traditional). Another group practiced using a manipulated task constraint with the objective of creating break on the ball without instructions for executing the pitch (Constraints-led approach). Based on frameworks from ecological and nonlinear dynamics, the Constraints-led approach was designed to enable pitchers to assemble movement solutions to satisfy task constraints while exploring functional movement patterns. The Constraints-led approach was compared to the Traditional approach which often overlooks the interacting dynamics of individual, environmental, and task constraints on motor behavior. Participants were randomly assigned to either condition. Initially, participants pitched peel drop balls during a pretest block of 15 pitches to collect baseline measures. Next, participants pitched three blocks of 15 peel drop ball pitches under their assigned condition which was followed by an immediate post/transfer test where the conditions were removed. Distal pitching-arm kinematics and ball metrics were obtained during the session. Each group performed similarly on the immediate post/transfer test assessed by average vertical break. The Traditional group showed greater mean vertical break during practice. Descriptive improvements in break occurred across practice for each group. Descriptively, the Constraints-led approach showed higher arm configuration variability during practice while the Traditional group reduced arm configuration variability, displaying more of a fixed movement pattern. Hand height variability at ball release showed to be a relatively stable parameter across blocks and similar between groups. The Traditional group displayed improved performance during practice, however when the task constraints during practice were removed performance was comparable.