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

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

Common mistakes

  • Elbows flaring out — on 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 moving — the upper arm should be pinned in place and only the forearm should move; if the elbow drifts, drop the weight.
  • Not finishing the rep — take every rep to a full triceps squeeze; on pushdowns that means a complete lockout for a count.
  • Cutting the stretch — on overhead extensions let the weight travel down behind the head until you feel the long head stretch before pressing up.

Where it fits in a workout

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

How many sets, how heavy and how hard: see what the ACSM position stands support.

Variations and alternatives

Similar exercises

Without barbell

Easier and harder

When to talk to someone

  • Chest discomfort, feeling faint or lightheaded, or trouble breathing during or after exercise can be signs of a heart attack. In the US, call 911 right away; elsewhere, call your local emergency number.
  • Heart, metabolic or kidney disease, or symptoms like these when you are active: talk to your doctor before you start or step up training.
  • Pregnant: ask your obstetric care provider which exercise suits you.

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More exercises

Sources

  1. ACSM position stand on exercise quantity and quality (Garber et al., 2011)
  2. ACSM preparticipation health screening (Riebe et al., 2015)
  3. ACOG Committee Opinion No. 804 on exercise in pregnancy (2020)
  4. CDC: About Heart Attack Symptoms, Risk, and Recovery (2024)

Sources checked on October 17, 2026. Full citations are in the exercise library.

Animation and exercise data: ExerciseDB, licensed to SetGrip. General information, not medical or coaching advice.