Barbell Skull Crushers

Target muscles

The triceps brachii is the prime mover — all three heads contribute, with the long head loaded through its greatest range because the shoulders are flexed forward. The anconeus assists with elbow extension. The forearms grip the bar isometrically. Done well, the skull crusher is one of the most direct triceps mass-builders available because the entire load travels through pure elbow extension; the chest and shoulders contribute almost nothing if the form is honest.

How to perform

Setup

Lie on a flat bench holding a barbell — an EZ-curl bar is gentler on the wrists than a straight bar, though both work. Grip just inside shoulder-width with an overhand grip. Start with the bar pressed over the chest, arms vertical or angled slightly back toward the head. Feet planted on the floor, trunk braced.

Execution

Bend the elbows only — the upper arms stay roughly stationary in their starting position — to lower the bar toward the forehead. Some lifters lower it just past the forehead; some bring it to the top of the head; some go to the bench behind the head for greater range. Pick a path and stay consistent through the set. Pause for a heartbeat at the bottom. Extend the elbows to press the bar back up to the starting position. Lock out the elbows briefly at the top. The upper arms shouldn't wave forward and back; if they do, the chest and shoulders are stealing work from the triceps.

Common mistakes

• Flaring the elbows out to the sides on the descent. Keep them pointed at the ceiling — flaring shifts the load to the chest.
• Letting the upper arms travel forward and back, converting the lift into a partial bench press. Lock the upper arms in their starting position.
• Going too heavy. The triceps tendon at the elbow takes a real beating from heavy extensions; honest 8-12 rep loads are the sweet spot.
• Bouncing the bar off the forehead. The name is a warning, not a permission slip.
• Lifting the head off the bench to get the bar past the face. Keep the head down; pick a longer bar path if you need more range.

Progressions and regressions

Regress to dumbbell triceps extensions (one or two dumbbells, easier to dose with strict form). Tricep pushdowns build elbow extension strength without the supine position. To progress, work the JM press (a hybrid bench-press / skull-crusher with elbows tucked in tight), incline skull crushers (slight head-up incline shifts the long-head stretch), or pause reps at the bottom for a sharper triceps stimulus.

Programming notes

Accessory work after the main pressing exercises. 3-4 sets of 8-12 reps. Once or twice a week. Pair with close-grip bench, dips, and tricep pushdowns for a complete triceps program. The elbow joint takes more wear from skull crushers than from most other triceps work, so cycle them in for blocks of 4-8 weeks rather than running them year-round.