Award Date

5-2013

Degree Type

Dissertation

Degree Name

Doctor of Physical Therapy (DPT)

Department

Physical Therapy

First Committee Member

Robbin Hickman, Research Project Coordinator

Second Committee Member

Merrill Landers

Number of Pages

44

Abstract

Purpose: The purpose of this study was to examine the effects of static and proprioceptive neuromuscular facilitation (PNF) stretching of shoulder internal rotators on throwing velocity as compared to a typical dynamic warm-up.

Subjects: 27 male untrained throwers (mean age = 25.1 years old, SD =2.4) with basic knowledge of throwing mechanics.

Methods:The study was conducted over a series of three sessions with at least one week between each session. During each session, subjects warmed-up, threw 10 pitches, were randomly assigned to one of three separate stretching protocols, and then threw 10 more pitches.The three protocols were static stretching, PNF stretching, and a control where no stretching was performed. Velocities were recorded after each pitch using a Bushnell Velocity Radar Gun and average and peak velocities were recorded after each session.

Results:

Data were analyzed using a 2x3 within factorial ANOVA. There was no significant interaction between stretching and throwing velocity. Main effects for average and peak throwing velocity were not statistically significant. Main effects for the stretching groups were statistically significant. Pearson product moment correlations were used to examine three relationships: 1) throwing velocity and external rotation (ER), 2) years of experience and ER, 3) years of experience and peak and average throwing velocities.The first two relationships were not significant. The relationship between years of experience and peak and average velocities was statistically significant.

Discussion: Results suggest that neither static nor a PNF stretching protocol focusing on increasing ER with no delay before throwing had a significant effect on throwing velocity in untrained throwers. Results may reflect the fact that throwing a baseball requires a complex neuromuscular pattern. The lack of training in the subjects could have affected the throwing velocity more than a specific stretching protocol. The motor learning needed for the complex task of throwing a baseball could have masked the effects of the stretching protocols.

Conclusions: Results of previous research on upper extremity stretching and its effects on throwing velocity has conflicting results. Further research should be performed in this area using a trained population in overhand pitching and with the use of an objective measure rather than a subjective measure for regulating stretch intensity.

Keywords

Arm; Pitching (Baseball); Shoulder; Stretch (Physiology); Stretching exercises

Disciplines

Kinesiotherapy | Physical Therapy | Rehabilitation and Therapy | Sports Sciences

Language

English


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