Baseball is one of the most physically challenging and demanding sports on the spine.
Baseball players create the highest force expression of all other sports, with fastball velocities climbing towards 100+ mph and exit velocities north of 115mph.
Athletes are REQUIRED to be proficient in high-level movements including thoracolumbar rotation, overhead shoulder flexion, extreme shoulder external rotation, scapular retraction, and the list goes on. Due to these high demands, training the thoracic spine (t-spine) to be both stable and mobile is imperative.
Baseball requires rotation, which happens at the hip, shoulder, and spinal level and moves up the kinetic chain (feet to fingers) during throwing, hitting, and running. The t-spine is a major part in creating high rotational velocities because it is centered directly in the middle of the body and is responsible for transferring force gained through the lower extremities (hips) to the upper (shoulder).
To make this happen, the t-spine must flex, extend, and rotate efficiently at high speeds.

Training the thoracic spine
Flexion is the most limited movement in the t-spine due to the structure of the vertebrae, which discourages our internal organs from being squished (thank goodness).
With that being said, thoracic flexion is mandatory for throwers because it allows the scapulothoracic joint to move smoothly.
Basically if an athlete can maximize and access their flexion, the scapula can glide over the ribcage and decelerate the shoulder in internal rotation effectively. Without enough flexion, the scapula gets “stuck” when trying to decelerate the shoulder after release and often causes posterior cuff/elbow issues.
It’s like having square wheels on your car and trying to drive 100 mph. It’s not going to end well.
Baseball players generally lack flexion because extension is where they spend the most time while throwing or hitting, therefore we need to train thoracic flexion in the gym.

Thoracic flexion
We find that movements that drive flexion while involving expansion of the rib cage using breath work are best to gain and maintain t-spine flexion.
So why do most players get stuck in extension?
Thoracic extension allows for more external rotation of the shoulder causing higher tension, which is then released with the ball or during the swing. Baseball players repeat moving into extension on every throw and swing, which slowly locks the t-spine up.
However, without thoracic extension, higher throwing velocities and bat speeds would not be possible.
Training extension in the gym is important but should only be done if a player:
- Can not get into end range extension
- Struggles to use extension with rotation
- Has a narrow infrasternal angle
- Lacks strength overhead
- Cannot dissociate between the lumbar and thoracic spine
Typically, extension movements/exercises should be accompanied with decompression of the rib cage through the breath and a neutral pelvis.
Thoracic rotation
Thoracic rotation starts at the lumbothoracic junction (where the lower and upper back meet) and sequentially moves upward towards the neck/shoulder during the swing/throwing motion.
Rotational athletes need to train rotation, but there is a time and place for this.
For example, training too much rotation in season can lead to overuse issues with the oblique, tight lower backs, and overall tissue breakdown. At the same time, not enough in the off-season can lead to a loss of range of motion and strength. However, it always depends on the athlete.
If a player wants to train to get better and not worse, knowing their body is priority one. So, if an athlete lacks t-spine rotational range of motion, train mobility.
If they lack the ability to decelerate in rotation, train anti-rotation.
The biggest part of training the spine properly is assessing what an athlete needs, exposing them to a stimulus, then reassessing.
Each day before starting skill work or training, the t-spine needs to be set in in a MORE neutral position and full range of motion must be achieved. This allows more force to be transferred up the kinetic chain, resulting in higher velocities.
Want to learn more about how to work with the scap to improve throwing output? Read here.
Looking to set up an assessment to see how to better train your t-spine for improved performance? Click here for AZ. Click here for CO.
Great article!