Throwing Injuries in Youth Baseball Players: Can a Prevention Program Help
Sakata J, Nakamura E, Suzuki T, Suzukawa M, Akeda M, Yamazaki T, Ellenbecker T, Hirose N. Am J Sports Med. 2019 [Epub ahead of print]
https://doi.org/10.1177/0363546519861378
Take-Home Message
Youth baseball players who participated in a weekly 10-minute prevention program experienced fewer shoulder or elbow injuries and improved performance compared to those that performed traditional warm-ups.
Summary
Shoulder and elbow injuries are common in youth baseball athletes. These injuries can lead to structural changes at those joints or invasive surgical repairs. Therefore, there is an urgent need for prevention programs to reduce the risk of throwing-related injuries. The authors of this randomized controlled trial investigated the effects of a 52-week exercise program performed at least once per week during a warm-up on new injuries among 237 youth (9-11 years of age) baseball players. The authors randomized 16 teams into two groups. The first group performed the modified Yokohama Baseball-9 (prevention program; 5 stretches, 2 dynamic mobility exercises, 2 balance training programs; 117 players) for 10 minutes during warmup. The control group performed their usual stretching and training program (120 players). The prevention program aimed to improve risk factors for throwing injuries: limited range of motion for elbow extension, posterior shoulder tightness, decreased shoulder and hip rotation, rotator cuff weakness, scapular dysfunction, rounded posture, and poor single-leg balance. Two physical therapists trained the athletes and coaches to perform the program. The teams performed the prevention program at least one time per week. The authors visited the teams every 16 weeks for clinical (pain, morphological change) and performance evaluations (pitching speed, range of motion, dynamic balance). Shoulder and elbow injuries were defined as pain that lasted >2 weeks, inability to play in a game or practice, pain with throwing, or abnormal findings on clinical assessment or ultrasonography.
Only 8 players were lost to follow-up in the intervention group, and 10 were lost to follow-up in the control group because they retired from baseball or moved away from the league. There was good compliance with 73% of the players in the intervention group completing the prevention program at least once per week (typically ~1.6 times/week). There were no differences in the number of pitchers in each group, but the authors failed to control for the number of pitches thrown. Over the 52-weeks, 24 players (22%; 1.7 per 1000 athletic exposures) in the intervention group reported a shoulder or elbow injury of the throwing arm. In comparison, 42 players in the control group (38%; 3.1 per 1000 athletic exposures) reported a shoulder or elbow injury of the throwing arm. The players that performed the prevention program also had more improved ball speed (~6.4km/h versus ~4.1km/h), range of motion (shoulder horizontal adduction and hip internal rotation), and improved posture compared the control group.
Viewpoints
The authors of this study found that a 10-minute throwing injury prevention program reduced throwing injuries and improved functional outcomes in youth baseball athletes. The risk of these injuries was almost 50% lower in the intervention group compared with the control group. This decrease in injuries is similar to what we observe with lower extremity injury prevention programs. Unlike those programs, the drop out was low and compliance was high, which suggests that this upper extremity program is easy to implement and maintain over a long time. It is also motivating for coaches and athletes to use this short program because it improved ball speed velocity and shoulder range of motion. Medical professionals should be aware of injury prevention programs for each sport and educate coaches, athletes, and parents about these programs. It is time that we step up and begin implementing these types of programs that are among the most effective prevention strategies available to the sports medicine community.
Questions for Discussion
Does this prevention program look feasible for your athletes? How can we increase buy-in from coaches and players to utilize the warmup more effectively to reduce injuries and improve performance?
Written by: Jane McDevitt
Reviewed by: Jeffrey Driban
Related Posts
Injury Prevention Programs Collide with Rugby…& Are Effective!
Injury Prevention for 6 Weeks = Better Landings for 6 Months
Injury Prevention Warm-Up Has Immediate Benefits
For Injury Prevention it is Better to Start Young
Injury Prevention Programs May Work if Your Athletes Use Them Regularly
Say it Again: Injury Prevention Programs WORK!!!!!

Yes, this program seems very feasible to me for several reasons. The first being the short length of time it takes. Ten minutes is a very small portion of time for a warm up routine, so most coaches wouldn’t look at it as an inconvenience. Also, if the routine can be easily followed by 9-11 year olds, a high school or college athlete should have no problem following it as well. We can increase the buy in from coaches and athletes by explaining the benefits of the warm up. Athletes and coaches alike are usually more compliant if they know why they are doing something instead of just being told to do it. A huge source that influences coaches and players is professional athletes, so if we as health professionals can show and explain to them that a professional sports team is doing this shoulder warm up they would be far more likely to want to do it as well.
One critique I have of the article is that the coaches and players were trained by physical therapists on how to perform the warm up without any supervision afterwards to ensure they are performing the techniques/exercises properly for the entirety of the study. I would also be curious as to what the control groups “usual stretching and warm up routine” consisted of. I believe another flaw of the study is that “the authors failed to control for the number of pitches thrown” by each pitcher (Summary, paragraph 2).
Michael,
Good points about their limitations. I do wish I would have seen pitch counts. Though pitchers in each group were similar we don’t know if one set threw more pitches and could have skewed the data. I am less critical about the supervision. The exercises seemed pretty easy and I think this adds to the external validity that they were able to continue doing the warm up and well enough that it did decrease risk. My only thought about performing this at a larger level is how can we reach enough of these little league teams/coaches/parents and train them so this research trickles down to them to see an actual change in the field.
I think this could be easily implemented throughout youth and even up to college baseball programs. Its short length and easy to understand exercises make it easy for the players to understand. Also, with it only being 10 min long it doesn’t seem like an inconvenience or a hassle. I also think that educating the coaches and players of the potential benefits that this program can bring will help increase compliance. Without this they may not fully understand why they should be doing the exercise and how it will better their performance. Also, by education the coaches or parents, they can help hold the athlete accountable. Finally, I also think that looking at pitch count would be interesting, and maybe even control pitch count.
I think baseball is one of the most common sports where parents want their kids to succeed in at a young age and also continue on throughout their high school and even college career. You see parents have their kids start to play baseball at age 4 or 5 with high expectations. I think that having a prevention program like this would be easy and beneficial for all ages to start and implement, especially considering that it doesn’t take long and can be included in their warm ups. To note that the risk of injury was almost 50% lower in the intervention group could be something to rely to the coaches to help them incorporate these exercises.
I think that this prevention program would be feasible for my athletes. I think you sell it to coaches by simply showing them the results of this study and then tracking the results of the team it is implemented on. Coaches should buy in when they see the results reported in the study actually happening for their team. I think it would be interesting to see if this program has differing results with older athletes or female throwing athletes.
Thank you for your comments.
I agree I think if we can gain buy in by showing them the ease, simplicity, and the positive research results we could get more athletes performing these prevention programs. I agree with you I would like to see this performed in other populations and age groups and see if the results are the same.
Rachel, like you said the sooner we implement this probably the better; however, when there is no medical professionals there to start this process (acknowledge there is a prevention program and educate the athletes and coaches on the exercises) it makes it tough. How can we disseminate this information to these youth leagues?
Brittany & Dakota, I also would like to see if this program would hold up in college or different populations like softball. Is this program intense enough to sufficiently warm the athletes up enough for the intensity at which these older athletes throw? I am sure this is not the only exercises they would implement for the warm up, but I imagine this could be a good start. I would like to see the similarities and differences of this warm up program to what they may be doing now in say the college setting. In this younger population they might not have had any structure to the warm up and now with this specific program to more efficiently warm up may have been the primary contribute to preventing injuries.