Flip to an underhand grip and torch the inner triceps.
Keep your wrist firm and elbow fixed, the underhand grip hits the medial head.
Flipping to a palm-up grip changes where the pressdown bites, the underhand position biases the medial head of the triceps, the workhorse that runs your lockouts, and doing it one arm at a time means your stronger side can't quietly carry the weaker one. The high cable keeps tension from the full stretch at the top to the squeeze at lockout. It earns its place as a detail exercise, the kind that fixes uneven arms and stubborn lockout weakness.
It shifts the emphasis toward the medial head of the triceps and forces a stricter, elbow-pinned path. It's noticeably harder than overhand at the same weight, so drop the stack and don't panic.
Holding a handle palm up while pulling down taxes your fingers and wrist more than the overhand version. Keep your wrist firm and locked, use a lighter weight, and grip strength catches up within a few weeks.
Alongside, not instead. Keep overhand pressdowns for heavier work and use the one-arm underhand version to even out imbalances and polish lockout strength at higher reps.
