Triceps · Isolation movement

Dumbbell Skull Crusher

A isolation exercise that targets the triceps. Performed with dumbbells, flat bench.

Primary muscle

Triceps

Secondary muscles

–

Equipment

Dumbbell

Difficulty

Beginner

What is the Dumbbell Skull Crusher?

The dumbbell skull crusher is a lying triceps isolation done with a dumbbell in each hand, lowering them toward the head and extending back up. Independent dumbbells let the arms move in a neutral grip, which eases wrist and elbow strain compared with a barbell while still loading all three triceps heads through a long range.

Muscles worked

Primary: Triceps
The triceps extends the elbows to press the dumbbells back up; with the upper arms angled slightly back, all three heads are loaded through a long range from a stretched bottom.

How to perform the Dumbbell Skull Crusher

  1. Lie on a flat bench holding a dumbbell in each hand, pressed up over the chest with a neutral grip so the palms face each other.
  2. The neutral dumbbell grip is gentler on the wrists and elbows than a straight bar and lets each arm move independently.
  3. Angle the upper arms slightly toward the head and keep them fixed there for the whole set.
  4. Bend the elbows to lower the dumbbells toward the sides of your head or ears, keeping them from flaring wide.
  5. Feel the stretch beside the head, then extend the elbows to press the dumbbells back up.
  6. Control the eccentric and avoid letting the dumbbells drift behind the head, which strains the elbow and shoulder.

Suggested working range: 10–15 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 and a dumbbell in each hand. The neutral grip and independent arms reduce the wrist and elbow strain a fixed barbell can cause, while keeping the triceps under stretch at the bottom.

Form cues

  • •Hold the dumbbells with a neutral grip and angle the upper arms slightly toward your head.
  • •Lower the dumbbells under control toward or beside your head, elbows tucked.
  • •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 back up.

Common mistakes

  • •Letting the dumbbells drift behind the head, which strains the elbow and shoulder.
  • •Flaring the elbows wide instead of keeping the upper arms fixed toward the head.
  • •Letting the upper arms drift toward vertical so tension drops off at the top.
  • •Dropping the dumbbells fast rather than controlling the eccentric beside the head.

Variations & alternatives

  • •Barbell skull crusher, both arms on one bar for heavier, simpler loading.
  • •EZ-bar skull crusher, an angled bar that’s gentler on the wrists.
  • •Incline dumbbell skull crusher: done on an incline to shift the stretch.
  • •Overhead dumbbell extension, a standing version loading the long head’s stretch.
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Programming: sets, reps & when to use it

Program the dumbbell skull crusher in the library’s 10–15 rep range as a triceps mass accessory after pressing. The neutral dumbbell grip is friendlier to the joints, so it suits slightly higher reps than a barbell version. Keep the lowering controlled and the elbows tucked, and don’t grind sloppy reps to failure under stretch.

Frequently asked questions

Dumbbells or a barbell for skull crushers?

Dumbbells let each arm move in a neutral grip, which eases wrist and elbow strain and evens out imbalances; a barbell is easier to load heavier and progress simply. If skull crushers bother your elbows, the neutral dumbbell version is usually the kinder choice.

Where do I lower the dumbbells to?

You can lower toward the forehead for a shorter, more tucked range, or down beside the ears/head for a longer stretch on the triceps. The neutral grip lets you pick whichever keeps the elbows tracking and pain-free.

Use this exercise in a program

The Dumbbell Skull Crusher fits naturally into hypertrophy and strength splits that prioritize triceps volume.

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