Why Arm Pain in Baseball Players Spikes in Week 5
Oct 15, 2026
Year in, year out, we see the same thing in the clinic when it comes to arm pain in baseball players. It doesn't happen in week one of a new season, nor does it happen in week 10. It happens in week 5 and here's why.
Let’s start with an anecdote. Years ago, we were down at practise, and one of our old standout pitchers was making a comeback after eight years out of the game. Mid-thirties, strong and with quite a bit of size, he strolled out and started rolling it over in the outfield. This then progressed to a light pen, and everybody thought how amazing it was that the big fella was back. And boy, did he have a bit of zip on his fastball.
While this is happening, as a baseball physio, I was thinking, "Yes, he looks good. But this isn't going to last."
I wasn’t having this thought to be negative – I loved seeing him out there having a crack. But I've been around one too many rotator cuffs to know that just because he was throwing with good velocity in his first session back, it didn’t mean his arm was going to hold up week after week. Especially after such a long period of deconditioning.
What happened? He started the season strong, had some great weeks back-to-back. Then, inevitably, he started to lose velocity around the week 4-6 mark. He wasn't coping with his throwing workload, and there it was: shoulder pain at week five.
This is an extremely common case, and one most players don’t see it coming. It also a prime example of having not thrown enough to cope with—not just one or two outings—but pitching week after week.
How do we solve or prevent elbow pain like this?
Throwing at a lower velocity or a lower intensity can be a lot better for your arm leading into the season. Because sometimes when you haven't thrown for a while, your arm feels tight in a good way – tight and whippy.
But when you don't have the training volume, the preseason or the repetitions to back it up, then inevitably your body will start to expose that lack of preparation. Interestingly, lack of adaptation (the clinical term for a sudden spike in use where the body wasn’t given time to adapt) usually shows up at the 4–6-week mark in other activities and sports: running, cycling, throwing, football. The body doesn’t discriminate – nobody is immune if they rush preparation.
Baseball players, pitchers in particular, must gradually expose their arm to throwing for many weeks before the season starts. Otherwise, what happens? They come out too strong, peak too early, and then they drop off with arm pain just as the season ramps up.
The key is throwing more often at a lower intensity, rather than coming back and thinking you've still got it when you don’t… yet!
This is precisely the reason we built the self-guided Arm Care Fundamentals system. Because we've seen and treated arm pain in baseball players for over a decade, and we know most of it could have been prevented.
On top of this, so many players come to us asking what's the right thing to do and when? All of this is answered in the program, which features around 1 hour of short, sharp, guided videos, and a fully customisable throwing program.
We made it with you in mind – check it out.
Or hit us up with your questions here – we write back to every email.