Skull Crusher

What is the Skull Crusher?

The skull crusher is a lying triceps isolation performed with a barbell, lowering the bar toward the forehead and extending back up. Lying flat with the upper arms angled back places a strong load on the triceps (including the long head) through a long range, which makes it one of the best mass-builders for the muscle.

Muscles worked

Primary: Triceps

The triceps extends the elbows to press the bar back up; with the upper arms angled slightly back over the head, all three heads are loaded through a long range.

How to perform the Skull Crusher

1. Lie on a flat bench holding a barbell or EZ-bar with a shoulder-width grip, arms pressed straight up over the chest or shoulders.
2. Angle the upper arms slightly back toward the head rather than straight vertical, which keeps tension on the triceps at lockout.
3. Keeping the upper arms fixed, bend the elbows to lower the bar toward your forehead or just behind the crown of the head.
4. Control the descent carefully; letting the bar path drift behind the head loads the elbow and shoulder more than the triceps.
5. Stop when the bar is near the forehead or hairline, keeping the elbows from flaring out to the sides.
6. Extend the elbows to press the bar back up, and do not bounce out of the bottom, which spikes elbow-tendon strain.

Suggested working range: 8–12 reps. Default progression: double progression.

Mechanics

A single-joint isolation performed lying on a bench: elbow extension with the upper arms held at a fixed backward angle. Keeping the upper arms angled toward the head (rather than straight up) keeps tension on the triceps at lockout instead of letting it rest over the shoulders.

Form cues

• •Angle the upper arms slightly back toward your head rather than straight up over the shoulders.
• •Lower the bar under control toward your forehead or just behind it, keeping the elbows in.
• •Extend by straightening the elbows only, keeping the upper arms at the same angle.
• •Don’t let the elbows flare out wide as you press; keep them tracking over the shoulders.

Common mistakes

• •Letting the bar path drift behind the head, which loads the elbow and shoulder over the triceps.
• •Flaring the elbows out to the sides instead of keeping the upper arms fixed.
• •Bouncing the bar out of the bottom, which sharply spikes elbow-tendon strain.
• •Letting the upper arms drift toward vertical so tension drops off at lockout.

Variations & alternatives

• •Dumbbell skull crusher, independent arms that ease wrist and elbow strain.
• •EZ-bar skull crusher: the angled bar is gentler on the wrists.
• •Incline skull crusher: done on an incline to shift the stretch on the triceps.
• •Overhead triceps extension, a standing version that loads the long head’s stretch.

Tricep Pushdown

Triceps · Cable

Overhead Tricep Extension

Triceps · Dumbbell

Tricep Dip

Triceps · Bodyweight

Close-Grip Bench Press

Triceps · Barbell

Diamond Push-Up

Triceps · Bodyweight

Programming: sets, reps & when to use it

Program the skull crusher in the library’s 8–12 rep range as a primary triceps mass builder, run after your pressing. Keep the lowering controlled and the elbows tucked; because the elbow is under stretch, avoid grinding sloppy reps to failure. An EZ bar is often kinder to the joints than a straight bar.

Frequently asked questions