This is Dr. Mike Marshall's "pitching forearm flyout." I have shortened the name for brevity.
When the pitching elbow moves in a pronounced arc, inertia slings the forearm away from the body. To keep the olecranon of the ulna from slamming into the olecranon fossa of the humerus, the brachialis muscle eccentrically contracts.
Reciprocal inhibition limits the contraction of the triceps brachii while the brachialis is contracting. The brachialis must relax before the triceps can fully contract. When forearm flyout occurs, the triceps brachii is not able to meaningfully contribute to the pitch.
- Pitch Movement, Part IV: Tunnel Vision
- June 25, 2020
- Scouting Grades: Power
- June 22, 2020
- Pitch Movement, Part III: The River of Seams
- April 2, 2020
- Pitch Movement, Part II: Sweet Seams (Are Made of This)
- March 15, 2020
- Pitch Movement, Part I: You Spin Me Round (Like a Baseball)
- February 28, 2020
- Scouting Grades: Speed
- February 20, 2020
- Still Learning 11 Years Later
- February 5, 2020
- Is it really supported by science?
- February 8, 2017
- To athletes seeking "exposure"
- February 1, 2017
- Discovering the Intent to Throw Hard
- January 25, 2017
- [posts archive]