Acute Effects of Upper Extremity Static Stretching and Dynamic Warm-up Protocols on Range of Motion, Strength, and Power Output

by Zaruta, Douglas A

INTRODUCTION: Overhead throwing athletes develop muscular and capsular tightness of the posterior shoulder and an altered arc of motion in their dominant shoulder due to repetitive overhead throwing. Stretching has been suggested as a way to improve soft tissue flexibility and reduce the risk of shoulder pathology associated with posterior shoulder tightness (PST). Baseball players commonly perform upper extremity acute static stretching exercises during warm-up to increase glenohumeral (GH) range of motion (ROM), prevent injury, and enhance performance. However, previous literature has demonstrated that acute static stretching may be detrimental to performance. The purpose of this study was (1) to compare upper extremity static stretching and dynamic warm-up protocols and (2) determine the most appropriate protocol to increase GH ROM, decrease PST, and maintain GH strength and power.

METHODS: Upper extremity static and dynamic protocols were compared in 15 healthy and physically active males using a within-subject, repeated measures, and counterbalanced design. GH internal rotation (IR) and external rotation (ER) ROM, PST, and GH isokinetic concentric strength and power were measured before and after each protocol. Post-test assessments occurred over four time intervals (post-0, post-5, post-15, and post-30 minutes).

RESULTS: The results of this study demonstrated no significant test x time interactions between the static and dynamic protocols at any time interval for any of the dependent variables. However, a significant main effect occurred where GH IR ROM group mean significantly increased at the post-0 (p=<0.001), post-5 (p=0.004), post-15 (p=0.017), and post-30 (p=0.050) time intervals compared to the pre-test measurement. GH ER ROM group mean also significantly increased at the post-5 (p=0.003), post-15 (p=0.003), and post-30 (p=0.017) time intervals compared to the pre-test measurement.

CONCLUSIONS: This study did not identify a stretching or warm-up protocol that increased or decreased muscular force output. However, both protocols acutely increased GH IR and ER ROM for up to 30 minutes, suggesting that static stretching and dynamic warm-up may be similarly effective at increasing ROM. Clinicians and researchers must continue to work together to guide future research and determine the most effective stretching or warm-up protocol to maximize upper extremity performance.