Why Range of Motion Beats Strength for Most Club Players

Racket-head speed depends on how fast you can accelerate the racket, and acceleration depends on both force and distance. The "distance" part is ROM. If your shoulder only rotates 90° where a tournament player rotates 120°, you have 25% less distance to accelerate over, no matter how strong you are.

The hip ROM / serve speed relationship

Hip ROM accounts for roughly 30% of the variance in serve speed among players at the same weight and strength level. A 15° hip ROM improvement translates to 4–7 km/h — more than a standard 12-week strength program produces.

Using your ROM card to find the limiter

The joint with the lowest ROM score relative to its benchmark is almost always the one limiting your progress.