For the next series of blogs, I’m going to discuss rehab throwing programs. Part one of this series will dive into the flaws with the current return to throwing protocol, namely instructions, intensity, and training load issues, and part two will outline our way of doing things at MSI.
Following a UCL reconstruction, athletes are typically cleared to begin throwing approximately four months after surgery. Upon clearance, athletes are given an interval throwing program from their doctor and sent on their way. While each orthopedic group has their own program, this is the main one our in-house physical therapists were using prior to my arrival:
Instructions
Athletes are instructed to throw every other day and to do each step 3-4 times before progressing to the next one. So, that usually means one step per week. Before throwing, the protocol calls for a warm-up and full body stretching; the stretches are not specified, the protocol only says the legs, trunk, back, neck, and arms should be stretched in a systematic fashion. While a qualified coach would be able to program a comprehensive warm-up, an athlete on his own may struggle to adequately prepare his body for the demands of throwing.
Alright, so after building out a throwing schedule and a systematic stretching routine, it’s now time to throw. First exercise on the list, warm-up throwing. Aside from “using the crow-hop method,” no further instruction is given on how to execute warm-up throwing. This may not be an issue when the athlete is throwing 45’ and 60’, but as distance progresses, what amount of volume is being added to a given day without being accounted for?
After warm-up throwing, athletes are instructed to make 25 throws at a specified distance. After the set, athletes are instructed to rest for 5-10 minutes before performing warm-up throwing again followed by 25 throws at the same specified distance. In my opinion, the implementation of rest intervals doesn’t make sense, and my thoughts regarding these rest intervals is pretty straightforward: if the athlete is fatigued or an energy system is depleted, rest. If not, don’t rest. While an in-depth look at energy systems is outside the scope of this article, I don’t believe throwing 25+ baseballs requires a 5-10 minute rest period. This would make more sense if the athlete was maxing out a squat or sprinting a 40yd dash.
Next, the method of throwing used for all throws in this program is the “crow-hop” method. The protocol recommends this because, “the crow-hop method simulates the throwing act, allowing emphasis of the proper body mechanics.” While I agree using the crow-hop allows for proper mechanics when executed properly, why should the entire body be used for all throwing, especially at the start of a program? By using a crow-hop, the lower half will generate forces that will transfer up to the torso, then to the arm. When sequenced properly, rotational velocities will increase for each segment. This is great if we are working with a healthy athlete, but maybe not as great for someone just starting to throw after 4+ months of surgery and rehab. It is my opinion that using the full body for the initial throwing stages creates forces that the athlete may not be ready to handle – both mentally and physically. So, if the athlete can’t handle the speed of his body, what happens? He slows down. More specifically, he slows down his arm. In my experience, the athlete will do two things: one, not maintain proper shoulder horizontal abduction through the stride and arm cocking phases, and two, limit dynamic external rotation through the arm acceleration phase. Both of these are clear deviations from any mechanical model I’ve reviewed, yet are common manifestations when an athlete starts his throwing program by crow-hopping. Alternate methods of throwing instruction and ways to avoid these pitfalls will be addressed in the following blog post.
Throwing Intensity
Next, let's discuss the progression of training load of the interval throwing program. Training load can be defined as volume x intensity for the purpose of this blog. Volume is simply the number of throws in a given day. Measuring intensity is where things get tricky. There are three ways throwing intensity typically gets measured: ball speed, rate of perceived exertion (RPE), or distance. Of these three, ball speed is the best option to truly measure intensity. Why?
One, athletes are poor at measuring their RPE compared with their peak output. Two recent studies have shown that pitchers produce higher than intended torques at submaximal RPEs.1,2 Both studies indicated the importance of understanding the implications of this evidence, and one1 advocated for the use of a radar gun to monitor throwing during the rehabilitation process.
Two, ball distance depends on two key factors (and many others) – velocity and vertical release angle. At the same velocity, a ball could travel 60’6” or 180’+ depending on the angle at which it is released. With that in mind, why would a throwing program that aims to closely monitor intensity have such a vague standard for measuring it? Granted, when these programs were first written, radar guns were not nearly as common as they are today. However, being that we are in the year 2020, maybe it’s time for an update.
Throwing Workload
Now, I’ll turn my attention to training load, and, more specifically, acute to chronic (AC) workload ratio. I covered AC ratio briefly in a previous post. To evaluate the interval throwing program, I calculated the workload for a given day based on the volume and intensity. Those calculations, along with a breakdown of the total workload over 13 weeks/phases can be found here.
A few things to note with this graph. While AC ratios are mostly in check (1.30 is on the higher end of safe), we see some jagged peaks and valleys week to week with the interval throwing program. One week training load increases significantly, and the next it drops off, only to increase again. A smoother increase in training load will help keep the AC ratio in line, and may decrease the chance of a setback.
So far, we’ve covered the instructions, intensity, and training load issues with the interval throwing program. While these are my main concerns with the current practice, there is one more aspect I’d like to cover – return to competition.
Return to Competition
After completing phase one of the interval throwing program, athletes progress to throwing off the mound. During this phase, athletes are instructed to throw a prescribed number of fastballs at a given RPE, similar to phase one. This progresses to throwing 45 fastballs in live batting practice at full effort. Then, after throwing 45 fastballs to hitters, it is finally time to add in off-speed pitches.
In my opinion, this is far too late to introduce off-speed pitches in the program. My reasoning for this relies on two main assumptions: one, the arm is stressed differently with different pitches;3,4 two, inverse dynamic analyses do not show how forces are dispersed over the individual muscles, tendons, and ligaments on a given pitch (and no published research since 2015 has dove into using a forward dynamics model in baseball).5 If one and two are true, then adding a new pitch (stimulus) at near maximal effort may overload the arm, causing a setback. Although the protocol states pitchers should throw these off-speed pitches at 50% and 75% effort first, we’ve already established that pitcher’s effort level and force production do not increase equally. So, not throwing a slider, curveball, or change-up until after facing hitters at max effort is, in my opinion, a major flaw when returning to competition. To be clear, I’m not advocating athletes throw their entire arsenal of pitches day one, but layering the stress and variety of different pitches should be implemented far earlier than currently recommended.
Conclusion
That concludes my review of the interval throwing program. Although this protocol has been the standard for many years, it is time for a change. The vague warm-up instructions may leave athletes confused how to best prepare their body to throw. The use of the crow-hop method may lead to negative mechanical adaptations if implemented at the onset of throwing. The programming of rest intervals doesn’t match the demands on the body. Measuring intensity using distance is an outdated method, and the spikes and drops in throwing volume lead to an uneven increase in stress. Finally, adding off-speed pitches after the athlete has already thrown to batters at maximal effort may excessively stress the arm.
In the next blog post, I will outline our system for rehabbing pitchers. This post will provide solutions to the flaws outlined above. Any questions or comments can be sent to gzirkel@maplezone.com.
References:
1. Lizzio, V. A., Smith, D. G., Jildeh, T. R., Gulledge, C. M., Swantek, A. J., Stephens, J. P., … Makhni, E. C. (2020). Importance of radar gun inclusion during return-to-throwing rehabilitation following ulnar collateral ligament reconstruction in baseball pitchers: a simulation study. Journal of Shoulder and Elbow Surgery, 29(3), 587–592.
2. Melugin, H. P., Larson, D. R., Fleisig, G. S., Conte, S., Fealy, S. A., Dines, J. S., … Camp, C. L. (2019). Baseball pitchers’ perceived effort does not match actual measured effort during a structured long-toss throwing program. The American Journal of Sports Medicine, 47(8), 1949–1954.
3. Escamilla, R. F., Fleisig, G. S., Groeschner, D., & Akizuki, K. (2017). Biomechanical comparisons among fastball, slider, curveball, and changeup pitch types and between balls and strikes in professional baseball pitchers. The American Journal of Sports Medicine, 45(14), 3358–3367.
4. Fleisig, G. S., Kingsley, D. S., Loftice, J. W., Dinnen, K. P., Ranganathan, R., Dun, S., … Andrews, J. R. (2006). Kinetic comparison among the fastball, curveball, change-up, and slider in collegiate baseball pitchers. The American Journal of Sports Medicine, 34(3), 423–430.
5. Buffi, J. H., Werner, K., Kepple, T., & Murray, W. M. (2015). Computing muscle, ligament, and osseous contributions to the elbow varus moment during baseball pitching. Annals of biomedical engineering, 43(2), 404–415.
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