There were 1,120 players injured in the MLB in 2021 resulting in 48,029 days on the DL. Of those 1,120 injured players, 298 of them (~26%) were injuries related to the shoulder or elbow, with shoulder injuries accounting for 128 of them. If you have been around the game you commonly hear of injuries to the ulnar collateral ligament, rotator cuff, glenoid labrum, and more recently the lat muscle. These types of injuries can be very complex and require proper rehabilitative care to return to pre-injury status. The aim of this blog is to discuss what we can do as rehab/performance specialists to predict arm injuries, and what measures we can take to keep our athletes healthy throughout the season.
QUICK ANATOMY REVIEW
Below is a quick reference of the most commonly injured structures in the arm amongst throwing athletes.
The shoulder is one of the most complex and freely moveable joints of the body. It is made up of 4 main joints: the most commonly thought of glenohumeral (GH) (ball and socket joint), sternoclavicular (SC), acromioclavicular (AC), and the scapulothoracic joint.
We are going to focus on the main muscles/and structures that we commonly see injuries in for the sake of this blog. As mentioned above the muscles of the rotator cuff are made up of the supraspinatus, infraspinatus, teres minor, and subscapularis. The rotator cuff is mainly involved in stabilizing and slowing down the shoulder in the throwing athlete.
In this illustration you can see the relationship between the muscles of the rotator cuff and the shoulder.
The glenoid labrum is a thick cartilage that forms and deepens the socket of the ball and socket joint. The tendon of the long head of the biceps brachii inserts on the superior aspect of the labrum and injury in this area is commonly referred to as a SLAP lesion/tear.
This illustration demonstrates the relationship of the glenoid labrum to the biceps tendon and the GH joint.
The latissimus dorsi is a long flat muscle that originates as low as the iliac crest and inserts on the anterior superior aspect of the humerus near the bicipital groove. Do to the insertion point, often times it is blended in with the insertion point of the teres major (not the rotator cuff muscle teres minor). The lat is primarily responsible for internal rotation of the shoulder, adduction, and extension of the humerus. The lats role in the throwing athlete is very dynamic.
This illustration demonstrates the latissimus dorsi and its origin and insertion points.
The elbow joint is made out of three bones: humerus (upper arm bone), the radius and the ulna (forearm bones). These three bones form three joints: radioulnar, humeroulnar, and humeroradial joints. Together they form what is commonly referred to as the “elbow joint”.
The elbow joint has a capsule that surrounds the joint, and it thickens at the medial aspect forming the ulnar collateral ligament complex (UCL). The UCL is made of three bands and is the most commonly stressed ligament of the elbow during throwing due to the high amounts of valgus stress placed on the ligament. This is the ligament that is repaired when you hear of a player having “Tommy John Surgery”.
This illustration demonstrates the elbow joint and the three bundles that make up the UCL .
Are We Good At Predicting Arm Injuries In Throwers?
In short, the answer is, it depends. There are some studies that demonstrate correlations between specific movement screening like cervical spine range of motion,and shoulder range of motion as predictors for arm injuries in throwers, but for the most part the number one predictor is over use.
The cheapest, and mostly effective way to monitor over use, is to monitor pitch count. The MLB Pitch Smart guidelines have recommendations for pitch counts and recommended days rest based on player age. The problems with pitch counts have been that it is up to the parents/coaches of youth athletes to monitor. We have shown time and again that unfortunately winning outweighs health most of the time, so these pitch counts are ignored in pursuit of winning.
With the advancement of motion capture and wearable technology, like driveline pulse, we are able to measure workload, torque on the elbow, arm speed, and arm angle at release. These metrics give us accurate, measurable stressors on the arm, which can be used to get a better understanding of the throwers use.
The use of wearable technology has also provided some interesting findings on what puts the most stress on the arm. For instance, it was once thought that Glenohumeral Internal Rotation Deficit (GIRD) led to an increase in torque on the elbow with throwers, but with the use of pulse, there is significant evidence that says otherwise. We see factors like player age, height, and BMI can be more of a predictor for increase/decrease in elbow torque with throwing.
Additionally research has shown that fastballs actually place more torque on the elbow than curveballs do. However before you go out and start having all of your young throwers start chucking curveballs, note that the same study showed, curveballs do produce greater arm speed. More importantly it shows that increased ball velocity, lower BMI, and lower arm slot are predictors for an increase in elbow torque. And additionally increasing age and arm size can protect against an increase in elbow torque.
So what does this mean?
General movement assessments can give us some help in predicting injury, but we should lean on overuse as the number one predictor of arm injury. We can also do our job to follow the recommended pitch counts, and if you have access to a wearable then use it to determine overall stress on the arm.
What Can We Do To Keep Arms Healthy?
A simple response is, just monitor pitch counts, however the most accurate answer is that it depends. Every player is different and will respond differently to a specific volume of throwing.
The cheapest and easiest way to monitor a player’s load from throwing is to simply monitor pitch count and limit them not only on a single outing pitch count, but an annual inning limit to prevent long term fatigue or injuries. There is research that shows youth athletes that throw more than 100 innings in a year are 3.5 times more likely to get injured. This simple approach is the best way to monitor overuse and prevent injury with youth athletes. Just simply keep them on a strict pitch count limit and monitor their innings within a one year window. It is important to note that throwing is important for developing proper mechanics and physical adaptations of the arm at young ages, so not throwing at all can be harmful, and limit performance as well.
When we look at highschool, college, and professional athletes we can get more specific with how we monitor their workload and piece together a better recovery program to get them ready for their next start.
Again a wearable device like driveline pulse or whoop, can be used to monitor the player’s workload and overall recovery. Additionally, at the professional level and some colleges they have access to technology that can give specific data on each pitch thrown and establish specific trends on each player. This allows them to know exactly when the player is starting to fatigue and pull them from the game.
Proper off season and in season training can also play a vital role in keeping arms healthy. Too often we see players make significant gains in the off season and then completely stop training in season. This can lead to regression and potential injury if not managed correctly.
We see this especially in the college game where guys go home over christmas break for a month and do nothing. Then when they try to ramp back up for the early spring season we see an increase in arm fatigue and soft tissue injuries. Proper management of your workload throughout the year can be vital to your overall longevity as a thrower.
This doesn’t only apply to pitchers but also position players. We must consider that different positions require different demands on the arm. Also, this may vary depending on the day. Some days any given position may make more plays than others, and the use of wearables can be used to monitor their workload. Additionally we need to note that there are various other times throughout the day that the players throw. Warm ups, in between innings, and flat ground/plyo work need to be considered as stressors on the arm.
If we can properly manage our throwers workload, we can ultimately help prevent overuse, enhance performance, and limit the risk of injury.
What Happens To Our Arm After An Outing?
When examining what we can do as rehab specialists to help our throwers recover faster, it is important to first realize the effects pitching/throwing has on the athlete’s arm.
We do know that there are some adaptations in ROM and strength that occur following pitching, but it is unclear the physiological causes of these acute changes. Studies have shown that immediately following an outing we have a decrease in internal rotation of the shoulder that doesn’t return to baseline for 4 days days, and external rotation strength does not normalize until day 3 after pitching.
On the med staff or strength and conditioning side, we can utilize this information to put together a plan to optimize recovery/performance, and ultimately prevent injury.
For the throwers we work with, shoulder ROM and strength (throwing and non throwing side) are measured in the initial assessment along with our OnBaseU screening following each off season. This gives us baseline numbers to refer to throughout the season.
Following an outing, we assess ROM and strength again and then piece together an individualized plan to help aid the athlete in returning to those baselines as fast as possible. It is important to note that we have to address starters, relief pitchers, and position players all differently. Also, on the highschool level they are typically on a 7 day rotation whereas the college and pro level guys may be on a shorter 5 day rotation before their next start, or a bullpen guy that may throw on consecutive days.
What Can We Do Between Starts To Help Recover Faster?
Before we dive into an example of a throwers recovery/training schedule that we use, it can’t be emphasized enough that the most important recovery tool is proper sleep and nutrition. Especially when we have someone who is struggling on the mound, and all they want to do is continue to work on things. Sometimes the simple fix is to just catch up on rest and get nutrition back on track. A simple way to keep our athletes on track nutritionally throughout the season is just to monitor body weight. The research shows us that higher BMI puts less stress on the arm, so we try to have our athletes maintain their body weight throughout the season. This also typically leads to less of a decrease in the offseason gains they made.
Using a 7 day rotation that we commonly see at the highschool level as an example, we like to build out a plan that involves alternating days of high intensity with days of low intensity training/activity. Again, each athlete will have a different plan, based on many different factors. It is important with our highschool athletes to keep in mind that they will more than likely play another position on the days they don’t start, so we need to consider that workload when designing this plan.
Here is an example of what a plan might look like for a thrower that we work with:
This is the day of their start. This is going to be a high workload day. Every pitcher verbalizes a little bit differently how their arm feels following a start, but most commonly we hear that the arm is tight or fatigued immediately following the outing. With the more recent evidence on the effects of icing, we typically don’t have our guys ice their arms. However, if they report pain, or if it is a personal preference for the pitcher then we will get them some ice. We recommend waiting until after their post throwing routine/exercise to ice.
As soon as possible following their outing we like to see the use of a marc pro, self myofascial release, and/or some light manual therapy from the athletic trainer or other rehab specialist on site if possible. This commonly isn’t the case with our highschool athletes, so this will typically happen on day 1 at the clinic.
Additionally on day 0/7 we like to see a lower body workout. Most of our highschool athletes don’t have the equipment available for this, so this too gets pushed to day 1. If that is the case we make sure they do some form of shorter interval cardio with bodyweight lower body exercises following their outing.
We typically stay away from heavy banded work or arm care routine imeddiately following the outing.
This is typically the first time we get hands on the athletes. We are able to take their baseline measurements and apply manual therapy if needed. It is important to note that we aren’t aggressively stretching the arm to return their internal rotation, but rather encouraging the increase in blood flow and returning the arm to proper mechanics. We avoid stretches like the sleeper stretch or partner stretching and opt for more functional type movements, like light banded work, plyos, or even light catch depending on the athlete.
We like to see light catch at short distances on this day. If this is a position player, we keep them out of the pregame high intensity throws, and if possible play them at a position that will be a little friendlier on the arm that day.
We also like to see light cardio or med ball work on this day. Again if this is a position player, they will get their light cardio in naturally. We then program specific med ball exercises for them that day.
This is a high workload day where we like to see an upper body or full body workout along with intense sprint work/plyo work.
They will also be doing their own self myofascial release and depending on how it feels, they will see the rehab specialist for manual therapy and or any of the recovery modalities we offer.
We still like to limit the amount of high intensity throws on this day for our position players, but they are likely back to playing their normal position. If they are a pitcher only, this is typically a light catch day where they may lengthen it a little depending on how they feel, and then work back in to 60 or shorter with emphasis on ptich grip and feel.
We like to see flat ground at roughly 65-70%. You can use the radar gun to monitor percentages, because athletes are not good at judging this off feeling alone. This is anywhere from 15-25 pitches followed by manual therapy or other modalities.
We also like to suggest a shorter, lower intensity 20 minute full body workout to prime the nervous system on this day.
If they are a position player, we like to see them build this flat ground into their pre game throwing.
Would be a more intense upper or lower body workout typically with some plyo/med ball work involved.
We should see their baseline assessment start to normalize by this point and they should be feeling pretty good.
If they are a position player, we adjust the workout based on what their workload looked like the day before during at the game.
We like to see this be their bullpen day, but depending on the athlete we switch this day with day 3 or 4. It is all based on the player's workload and how they are feeling. Typically they will get in a routine that stays consistent throughout the season.
They will also do some cardio interval training, and continue with their manual therapy/self care if needed based on how they look compared to their baseline.
This is a light cardio day, and the rehab staff is doing what they can to help this player feel their best going into their start on day 7.
If this is a position player, we can give them this day off, or move them to a position that has fewer high intensity throws.
This is the day of the next start, and we repeat the cycle again.
Again we are monitoring the players workload with pitch count/throw count throughout the week. If you have the resources to use wearable technology then it is used. We refer back to their preseason baseline tests multiple times throughout the week to ensure that they are in the best position to perform their best while avoiding injury.
This timeline is obviously different for athletes on a different rotation or if they are relief pitchers.
Also, keep in mind that the workouts scheduled aren’t always long, max effort sessions. At times they can be short sessions that are meant to prime the nervous system and keep us moving. Just make sure the athlete knows the intent of the training session and they are locked in on that goal. We don’t want to just be training, just to train. These younger athletes should still be focused on development in season, whereas your professional athletes will be focused on maintaining their off season gains.
In conclusion, we know that arm injuries in the sport are present and seemingly more prevalent with kids specializing at younger ages. It is important for coaches and parents to monitor these young athletes' workload to lessen the risk of these injuries. Also, with the right team, we can manage these athletes year round to put them in the best possible position for optimal performance and reduce the risk of injury.
If you have any questions on how to monitor your recovery post throwing or are looking for a rehab specialist to help, please reach out to the clinic and we can get you started.