Behind Head Barbell Skull Crusher

Also known as: behind head skull crusher, behind the head skull crusher, behind the head skull crushers, skull crusher behind head, barbell behind the head triceps extension, barbell back of the head lying tricep extension

In SetGrip: Barbell Skull Crusher (Behind Head)

Secondary muscles
Delts
Body part
Upper Arms
Position
Lying
Laterality
Bilateral (both sides together)
Category
Strength

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Lowering the bar past your head instead of stopping at the forehead lengthens the range and puts the long head under a deeper stretch. It also keeps tension on the triceps at the top, because the bar never stacks directly over your elbows the way it does in a standard barbell skull crusher. Expect to use somewhat less weight.

How to do the Behind Head Barbell Skull Crusher

  1. Lie flat on a bench with your feet flat on the ground and your head at the end of the bench.
  2. Hold a barbell with an overhand grip, hands shoulder-width apart, and extend your arms straight up over your chest.
  3. Keeping your upper arms stationary, slowly lower the barbell behind your head by bending your elbows.
  4. Pause for a moment, then extend your arms back up to the starting position.
  5. Repeat for the desired number of repetitions.

Tip: Keep a slight bend at the top on lying extensions to protect the elbow, but lock out fully on cable pushdowns.

Muscles worked

Primary

Triceps · Arms

The triceps straighten the elbow, and overhead variations stretch the long head at the bottom, so you should feel the whole back of the upper arm working with a hard squeeze at lockout.

Secondary

  • DeltsThe front delt holds the upper arm in position on overhead extensions and should feel tension but not be lifting.

Common mistakes

  • Elbows flaring outon overhead and lying extensions the elbows should stay pointed forward or up, not out to the sides, since flaring turns it into a press.
  • Upper arm movingthe upper arm should be pinned in place and only the forearm should move; if the elbow drifts, drop the weight.
  • Not finishing the reptake every rep to a full triceps squeeze; on pushdowns that means a complete lockout for a count.
  • Cutting the stretchon overhead extensions let the weight travel down behind the head until you feel the long head stretch before pressing up.

Sets, reps and where it fits

GoalSets × repsRest
Muscle growth3–4 × 10–1560–90 s
Endurance / finisher2–3 × 15–2045 s
StrengthNot ideal — pick a compound lift for the same muscle

Triceps extensions go after the presses in a push session or at the end of an arm day. Superset them with biceps curls on the same cable stack or with the same dumbbells.

Variations and alternatives

Frequently asked questions

What muscles does the Behind Head Barbell Skull Crusher work?

The Behind Head Barbell Skull Crusher primarily works the triceps. It also involves the delts, which assist the movement and stabilise the joints.

Is the Behind Head Barbell Skull Crusher good for beginners?

It is rated intermediate, so it suits people who already train regularly. Beginners can still do the Behind Head Barbell Skull Crusher with light load and a spotter or coach watching the first few sessions; if it feels awkward, pick an easier variation from the alternatives below first.

What can I do instead of the Behind Head Barbell Skull Crusher?

If you cannot do the Behind Head Barbell Skull Crusher, try the Kneeling Bodyweight Triceps Extension, the Seated Barbell Overhead Triceps Extension or the Decline EZ-Bar Skull Crusher. Each of them trains the triceps through a similar movement, so you can swap them in without changing the rest of the workout.

How many sets and reps should I do?

It depends on your goal. For the Behind Head Barbell Skull Crusher, a sensible starting point is muscle growth: 3–4 × 10–15 with 60–90 s rest; endurance / finisher: 2–3 × 15–20 with 45 s rest. Do it after your compound lifts. It is a finishing movement, not the main event.

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