Escamilla RF, Yamashiro K, Mikla T, Collins J, Lieppman K, Andrews JR. Effects of a short-duration stretching drill after pitching on elbow and shoulder range of motion in professional baseball pitchers. Am J Sports Med. 2016;45(3):692-700. doi:10.1177/0363546516671943.
An internal rotation (IR) deficit of approximately 20-25 degrees or greater and a total rotational motion deficit of greater than 5 degrees has been shown to increase the risk of shoulder and elbow injuries in baseball players2,3. Other research has shown a significant decrease in IR range of motion (9.5 degrees), total rotational motion (10.7 degrees), and elbow extension (3.2 degrees) in the throwing arm of asymptomatic professional pitchers within 30 minutes of completing a pitching session1. It is unclear if this IR deficit and total rotational motion deficit may eventually result in greater risk of shoulder and elbow injuries.
The purpose of this study was to assess the effectiveness of a short stretching drill, the two-out drill, in terms of being able to restore IR, ER, total rotational motion, and elbow extension back to pre- pitching levels.
- Professional baseball players (n=20)
- Mean age 23.9 years
- Seven left-handed pitchers, 13 right-handed pitchers
- Excluded: undergone surgery on the elbow or shoulder within the previous 12 months
After performing a warm-up throwing session, research participants underwent assessment of passive range of motion (PROM). Shoulder ER and IR PROM measurements were performed with the shoulder abducted 90 degrees and horizontally adducted 10 degrees. Elbow extension was tested with the participant positioned supine, the throwing shoulder abducted 30 degrees, and the throwing forearm fully supinated.
Immediately following PROM measurement, the participant pitched off the mound throwing 40 hard pitches with 5-10 seconds between pitches. Immediately after the pitching session, an 8-minute timer was started to simulate rest between a typical inning of a baseball game. The participant was instructed to rest and do what he would normally do between innings when not pitching without any stretching. After the 8-minute timer expired, the participant’s shoulder and elbow PROM were immediately measured again.
After the post-pitching shoulder and elbow PROM measurements, each participant then performed the two-out drill, which took approximately 60 seconds to complete. The two-out drill consists of seven upper body exercises performed in sequence. Immediately after performing the two-out drill, shoulder and elbow PROM measurements were taken for a third time (post-drill measurements) by the same examiner.
- Shoulder ER PROM: significantly greater PROM pre-pitching (94⸰) compared with post-pitching (88⸰) conditions, and significantly greater PROM post-drill (94⸰) compared with the post-pitching conditions.
- Shoulder IR PROM: significantly greater PROM pre-pitching (36⸰) compared with the post-pitching (30⸰) conditions, and significantly greater ROM post-drill (35⸰) compared with the post-pitching conditions.
- Total rotational PROM: significantly greater PROM in the pre-pitching (129⸰) compared with the post-pitching (119⸰) conditions, significantly greater PROM in the post-drill (129⸰) compared with the post-pitching conditions.
- There were no significant differences in elbow extension PROM between conditions.
- The PROM measurements were made with passive overpressure removed. Therefore, the reported shoulder IR and ER PROM measurements in this study may not be comparable to those from other research.
- These results may not be generalizable to non-professional baseball pitchers.
- The two-out drill has not been investigated under competitive game situations.
Practical Implications & Additional Thoughts
Following a simulated pitching session, pitchers showed a significant decrease in IR, ER, and total rotational PROM, but not elbow PROM. Performing the two-out drill restored shoulder PROM back to pre-pitching levels. The two-out drill can be performed in approximately one minute. Thus, performing the drill with two outs will allow adequate time to prepare the throwing shoulder for the subsequent inning. This may be a practical and effective means to preserve shoulder PROM throughout the course of a baseball game.
It is unclear if preserving shoulder PROM during a baseball game can reduce risk for arm injury. Wilk et al.2 showed pitchers with IR deficits (>20⸰) or total rotational motion deficits (>5⸰) were at a higher risk for shoulder injuries and surgery. Total rotational motion deficits of >5⸰ in the throwing shoulder has also been shown to result in a 2.6 times’ greater risk for elbow injury3. Future studies should directly assess the effects of the two-out drill on reducing arm injuries during a competitive season. Also, future studies should investigate the effects of the drill on shoulder PROM over several days after throwing, as well as over the course of an entire season.
More research is needed before definite conclusions can be made regarding the efficacy of performing the two-out drill. However, these preliminary results appear promising and worthy of incorporating with baseball players seeking between inning warm-up routines. On a personal level, I am excited to implement the two-out drill with some local youth baseball players this coming season.
- Reinold MM, Wilk KE, Macrina LC, et al. Changes in shoulder and elbow passive range of motion after pitching in professional baseball players. Am J Sports Med. 2008;36(3):523-527. doi:10.1177/0363546507308935.
- Wilk KE, Macrina LC, Fleisig GS, et al. Correlation of glenohumeral internal rotation deficit and total rotational motion to shoulder injuries in professional baseball pitchers. Am J Sports Med. 2011;39(2):329-335. doi:10.1177/0363546510384223.
- Wilk KE, Macrina LC, Fleisig GS, et al. Deficits in glenohumeral passive range of motion increase risk of elbow injury in professional baseball pitchers: A prospective study. Am J Sports Med. 2014;42(9):2075-2081. doi:10.1177/0363546514538