05/02/2026
Proper isometric & eccentric loading of the flexor-pronator mass is crucial for long-term elbow health and UCL protection in pitchers. There’s nothing wrong with doing dumbbell wrist curls or rice bucket drills early on in rehab to build a foundation, but in my opinion they don’t properly prepare the tissue for a return-to-throwing.
Here is a pronation-specific isometric we will use to further stress the ability of the FPM to protect the UCL and stabilize the medial elbow. The trick here is making sure that force is being primarily generated from the forearm, rather than through the shoulder. To gradually acclimate the elbow to this type of loading, we start with a low intensity, longer duration prescription (typically 4x30-45”) before progressing to more strength and rate of force development variations.
We also can’t forget the importance of consistently loading the FDS & FCU, which are the 2 primary dynamic stabilizers of the elbow that protect the UCL.
For non-baseball athletes dealing with flexor tendon issues, this can also serve as an appropriate way to load the medial elbow.