A Science-Based Look at When to Worry and When to Rest
By Dr. John Mishock, PT, DPT, DC
Arm pain after throwing is a common complaint among baseball players at all levels-from Little League to the Major Leagues. But is all post-throwing pain a red flag? Or can some soreness be part of the normal adaptation process? Let’s explore what the best available science says about post-throwing arm discomfort, how to distinguish between adaptation and injury, and when to seek treatment.
Understanding the Throwing Arm:
Throwing a baseball is among the most stressful motions in sports. During the late cocking and acceleration phases of pitching, the shoulder experiences angular velocities over 7,000° per second and internal joint forces exceeding 80% of body weight at the elbow (Fleisig et al., 1995). Despite this, the human arm is capable of remarkable adaptation-when exposed to progressive, well-managed workloads. Mild soreness or muscular fatigue after throwing may indicate natural adaptation, especially in-season or after workload increases.
What the Research Says About “Normal” Arm Pain:
A landmark study by Olsen et al. (2006) found that 46% of youth pitchers reported arm pain in a given season-but pain lasting more than 4 days or limiting throwing ability was associated with a 4-fold increased risk of serious injury. Shanley et al. (2011) similarly found that pain persisting beyond 3 throwing sessions predicted shoulder and elbow injuries in high school pitchers.
Key Takeaway: Is Arm Pain After Throwing Always Bad? Mild muscle soreness that resolves in 1-2 days is likely adaptive. Pain that lingers, worsens, or limits performance should not be ignored. Differentiating Good Soreness from Concerning Pain Adaptive pain: located in muscle belly, resolves in 3-4 days, worsens or stays same, causes velocity/control loss.
Understanding the Pain-Injury Continuum
1. Adaptive Response – mild soreness from workload increase
2. Overload Zone – recurring discomfort with poor mechanics or high volume
3. Pathologic Injury – structural issues like UCL tears or tendinopathy
The Biomechanical Link Poor mechanics, such as early trunk rotation or reduced hip-shoulder separation, increase joint load and injury risk (Aguinaldo et al., 2007). Pain can be a marker of inefficient movement.
Clinical Guidelines:
When to Refer or Treat – Pain >3 days
Loss of range of motion
Decreased velocity or control
History of ‘dead arm’ or prior injury
Rehab should emphasize posterior shoulder strength, scapular stability, trunk and lower body strength, and power development. (Tyler et al., 2014).
Bottom Line: Pain Isn’t Always Bad-But It’s Always a Signal Is Arm Pain After Throwing Always Bad? Some arm soreness is natural and adaptive. But if pain persists, worsens, or impacts performance, it’s a sign to assess mechanics, reduce load, or initiate rehab. Prevention and early intervention are the keys to a durable throwing arm. If you or your athlete is struggling with throwing pain, consider a movement assessment and custom rehab program. Prevention is always more effective than recovery.
We can help!
If pain is limiting you from doing the activities you enjoy, give Mishock Physical Therapy a call: locations in Gilbertsville (610-327-2600), Skippack (610-584-1400) , Phoenixville (610-933-3371), Boyertown (610- 845-5000), Limerick (484-948-2800) at www.mishockpt.com or request your appointment by clicking here.
Dr. Mishock is one of only a few clinicians with doctorate-level degrees in both physical therapy and chiropractic in the state of Pennsylvania. He has also authored two books; “Fundamental Training Principles: Essential Knowledge for Building the Elite Athlete”, “The Rubber Arm; Using Science to Increase Pitch Control, Improve Velocity, and Prevent Elbow and Shoulder Injury” both can be bought on Amazon or train2playsports.com.
