One of the most confusing questions for a baseball parent or coach is how to know when a pitcher is experiencing fatigue, soreness, or pain.  As a physical therapist, athletic trainer and performance coach, I have the fortune of working at all levels of baseball, from youth to professional.  And this question comes up over and over again and is really hard to determine.  So, I want to give you some guidelines and some ideas on how you can tell the difference.  

One of the first things that we need to understand is people perceive pain differently.  And, the younger the person is, the more likely that they will perceive it differently than you do.  Meaning as a coach or a parent, you might not perceive pain the same as a younger person.  And when I say younger,  I mean anyone between elementary and college-aged. Depending on the person's previous experience with pain, they may be very sensitive to pain or they may be less sensitive.  It is a matter of how they're internally wired and previous interaction with their environment.  This is one of the reasons this question is so hard to answer --  we all perceive pain differently.  

Thn how do you tell the difference?   The first thing we need to do is define a few terms.   We need to define fatigue, soreness, and pain.  These can occur on a continuum, meaning it can start out as fatigue, and then become soreness a few days later, and then ultimately develop into pain.  Or they can occur independently of each other.   It's really important to understand that fatigue, soreness, and pain have similar characteristics and are closely intertwined.  

Let's start off with fatigue.  Here are some of the characteristics of fatigue: muscles feel tired,  they feel full and blood engorged (like a muscle pump after weightlifting).  Fatigue may start to change the player's mechanics and their ability to locate pitches.   But, you also have to remember, that can be a characteristic of pain as well.  The key characteristics of fatigue are muscle tiredness and the muscle fullness feeling.

Soreness on the other hand, usually develops within 24 - 48 hours after the activity and resolves by 72 hours.  It doesn't develop immediately, but rather gradually after pitching.  This soreness should ideally be in multiple areas of the body and in multiple muscles.  The muscles may feel tender, tight or stiff.   It may feel relief with movement.  Stretching definitely helps with soreness.  The key characteristics of soreness are  time frame, that it is located in the muscles, gets relief with stretching, and that it is felt in several different areas of the body.  

Pain, on the other hand, usually is localized to only one place.  It tends to come on more quickly, it has a sharper quality, but that sharpness may be deep in the joint as well.  It's located either in the bone or the joint, unless we have a true trauma where we know the muscle was injured (hit by a ball, a strained muscle with a known time of injury, etc.).  This sensation tends to linger more than three days and it gets worse with activity.  The more activity you have, the worse it feels. 

There are a lot of different characteristics and these characteristics can overlap each other, and that's what makes it a challenge.   How do we determine whether our pitcher is experiencing fatigue, soreness, or pain?  The short answer is it depends on multiple factors.  We can't just take one factor and determine that it's one or the other.   We have to put all the pieces together. 

• How does the player perceive pain? 
• What is the timeframe of onset? 
• Where is the discomfort located? 
• Does movement provide relief or make it worse?   

I think most of the time, coaches and parents tend to diminish or minimize their player's pain.  And so I want to caution you against that.   

In order to determine whether your pitcher is experiencing fatigue, soreness, or pain, consider these steps:

 First, try to define it.   Does it meet the characteristics of fatigue, soreness, or pain?  Really dive into that.   Where is it located?  How long does it last?  When does it come on?  What relieves it?  What makes it worse?   

Next, where is the sensation located?  This can give us a lot of insight.  For example, if we are going to have fatigue or soreness, it's good if we see it in the back of the shoulder,  glutes, and abs.  This is where we want to feel fatigue and soreness.  Unless there's a very acute injury where something happened or we know it's a really sharp localized pain. Otherwise, these are exactly where you want to feel fatigue and soreness with pitching.  Anytime a player tells me, “Oh I'm hurting,” and they show me these areas (back of shoulder, glutes, abs), I love it.  I say that's great, and this is a good opportunity to teach the player the difference between soreness, fatigue, and pain . . . because this is either soreness or fatigue, depending on what time frame it's happening.  

These are also areas of the body that are almost always considered pain . . . right in the front of the shoulder, right on the bony area of the shoulder, and on the inside of that elbow, right on the bone or just off of the bone.  We're going to almost always call this pain, especially in isolation.  If it meets those other qualities . . . that it's sharp, that it hurts quite a bit, it gets worse with activity . . .  this is definitely in the pain category.  

Now I'm going to talk about the caution areas.  These are areas where sometimes I'm okay with it, sometimes I'm not.  When we're looking at the bicep and the forearm, right in the muscle belly,  this can be an okay area.  This is an area that does fatigue, so I'm not saying this is worrisome.  But it can also be a precursor to developing shoulder and elbow problems as well.  This is kind of a warning light.  It's kind of a sign that causes me to say “wait a second, how are things going?”  I will say that if we have good fatigue in the abs and the back of the shoulder and the glutes, I'm absolutely okay with this fatigue in the biceps and the forearm.  That's a natural thing.   We are distributing that load throughout the body, which tends to be a better sign.  However, if this is the only place we're feeling it, particularly in younger athletes, we better make sure their movement and mechanics are solid. Poor movement, poor mechanics, and poor core control will lead us to overuse as these muscles try to stabilize the biceps and the forearm.   

One other area that can be a yellow light is being very point tender in the back of the shoulder, especially if they describe it more as a pinch.  If it's being described more as a pinch than a soreness, and it's located right on that back side of the shoulder where that yellow dot is, that's going to be a caution light.  That's going to be something I'm going to be more concerned about.  

The final thing that we're going to look at as we try to determine the difference between fatigue, soreness, and pain is the question "Are there any red flags present?".  The first red flag is if a player is taking Advil or Tylenol for the feeling, for the sensation that they are having, that is pain.  So we really should not be taking Advil, Tylenol, or any other pain reliever to be able to pitch or after pitching.  That is not part of a normal pitching routine.  Now, if the soreness is so bad that the pitcher has to take anti-inflammatories, it's probably actually pain.  Remember, anti-inflammatories are not vitamins.   We're not deficient in ibuprofen or acetaminophen in our body.   If your players are taking anit-inflammatories after pitching especially without advice from their physician, that's a red flag.  That tells us that we have pain.  

If it is soreness, we want them to actually feel that soreness so they can guide themselves through their activity levels over the next days.  After pitching, we're going to do tissue recovery.  We're going to do our exercises to help recover the day of pitching.  The day after pitching,  we'll do throwing and additional recovery exercises.  It's important to have a very solid plan of recovery after pitching.    

Another red flag is pain in the elbow and shoulder at the start of throwing and pitching, particularly if that pain doesn't get better.  That really tells us a lot.  Pain in the front of the shoulder, pain in the elbow right when we start is not what we want, especially if it gets worse with repeated throwing.

I hope these guidelines have helped you answer the challenging question of differentiating fatigue, soreness, and pain.  If you have any questions, don't hesitate to reach out to us.  For a detailed program on making sure your pitcher is ready to perform, check out our free program, Pitcher Readiness, or our in-depth pitcher training program, Pitcher Performance & Durability.

About the Author

Phil Plisky, PT, DSc, OCS, ATC, CSCS

Dr. Plisky is a physical therapist, athletic trainer, strength and conditioning coach, and Professor in the Doctor of Physical Therapy Program at the University of Evansville. As a performance systems consultant with all major professional sports and the military, his passion is teaching athletes how to elevate their game to the next level.