A 2025 study found that pitchers who show excessive trunk and pelvic rotation during a simple single-leg step-down test are far more likely to throw with higher elbow torque and lower velocity. The issue isn’t general movement quality—it’s specifically poor transverse-plane control, which reflects deficits in the lumbopelvic-hip region and disrupts efficient energy transfer up the chain. For coaches, the takeaway is clear: a quick step-down screen can flag rotational control problems early and guide targeted training before performance drops or the elbow starts paying the price.
