🎾 Tennis Doctor

Alcaraz's forehand is a masterclass in modern biomechanics. The key is his leg drive — he uses an exaggerated crouch in his unit turn to load his posterior chain, then explodes upward through ground reaction force. Combined with his "loop" forehand trajectory (high takeback, low finish) and a passive wrist (no active flexion), this lets him transfer energy from the ground through his kinetic chain in roughly 0.3 seconds. His forehand averages 78 mph with 2,500+ rpm topspin.

The kinetic chain is the sequential transfer of energy from the ground, through your legs, hips, torso, shoulder, arm, and finally the racket. Each link "adds" rotational and linear velocity. For example, ground reaction force → hip rotation → torso coil → shoulder whip → arm lag → racket head speed. Studies show roughly 50% of racket head speed comes from the legs and core, only 30% from the arm. If you break the chain (e.g. by "arming" the ball), you lose power and increase injury risk.

Three priority adjustments: (1) Stop doing deep squats with heavy load — replace with Bulgarian split squats and box squats to keep knees tracking over toes without compressive load. (2) Strengthen VMO (inner quad) and glute medius to stabilize patellar tracking. (3) On court, use a "tension-not-overload" rule: keep tension in your legs but never lock your knees — think "bridge by straight front leg" rather than "push off bent knee". Also consider switching to a softer court surface and using supportive tennis shoes with lateral stability.

The 70% Rule (popularized by Craig O'Shannessy) is the insight that professional tennis players only win ~54% of total points, but win ~70% of points when they are "in control" (defined as hitting a neutral or aggressive shot). The implication: don't try to win every point — focus on getting your opponent "on the run" or "in defense" first. The 70% rule is a tactical framework that emphasizes point construction over winner-hunting.