Barbell · intermediate · upper arms
Barbell skull crushers
Also called Lying triceps extension, French press, Nose breakers, EZ bar skull crusher, French extension.
Skull crushers lie you on a bench, hold your upper arms still, and bend and straighten your elbows against a bar. Your triceps are the muscles doing the work and nothing else is. The detail that matters is where you lower the bar: the long head of the triceps crosses your shoulder as well as your elbow, so taking the bar behind your head rather than to your forehead loads it at more length.
How to do it
- Step oneLie flat on a bench and hold an ez curl bar with an overhand grip, arms extended directly above your chest.
- Step twoKeeping your upper arms vertical and elbows pointing toward the ceiling, slowly lower the bar toward your forehead.
- Step threePause just above your forehead, then extend your arms back to the starting position by contracting your triceps.
- Step fourKeep your elbows tucked and avoid flaring them outward throughout the movement.
What usually goes wrong
Each starts with what you would notice.
Your elbows drift apart as the bar comes down.
WhyThe upper arms are rotating out, so the line of pull stops running straight through the elbow and starts pushing it sideways instead.
FixSet the elbows about shoulder width and keep them pointing at the ceiling all the way through. If they will not stay, the bar is heavier than your triceps can hold in position on their own.
You feel it in the joint rather than in the muscle.
WhyUsually the bar is going to your forehead, which cuts the range short and stops the stretch where it was about to do something useful.
FixLower behind the top of your head instead, letting the upper arms tip back a little as you go. That keeps the triceps loaded through more of its length and takes the sharpness off the elbow.
Something snaps or jars at the top of every rep.
WhyYou are throwing the elbow into a hard lockout, which hands the load off the muscle and onto the joint at the exact moment the muscle stops working.
FixStop just short of straight and start the next rep from there. There is nothing at the very top worth reaching for on this exercise.
Your wrists bend back and your forearms ache.
WhyThe wrists are collapsing under the bar, so the forearm is out of line with the load and the twist is going into the elbow.
FixKeep the knuckles stacked over the forearm. An EZ bar makes this much easier because the bends let your hands sit at an angle instead of square.
Skull crusher or triceps pushdown
This one has a genuine answer and it comes from arm position. The long head of the triceps runs over the shoulder joint, so how far back your upper arm is decides how stretched that head is while you work it.
A 12-week study trained one arm overhead and the other with the arm at the side, everything else matched. The long head grew about half again as much in the overhead position, and that was with lighter weights.
A pushdown is the arm-at-the-side condition. A skull crusher tips your upper arm back further than that, and a full overhead extension goes further still. So the scale is real and a skull crusher is well up it, especially if you lower behind your head rather than to your face.
The name is the worst part of it
The name is the problem with this exercise. Lowering a bar to your forehead is where it came from and it is not the version worth doing, because stopping at your face shortens exactly the part of the range the long head was about to be stretched through.
It is also not the elbow-destroyer it gets called. The discomfort people report is tied consistently to three things you can change: elbows flaring out, snapping into lockout, and wrists folding back.
What it will not do is train your shoulders or your chest, whatever a bar in your hands suggests. It is one joint doing one thing, which is the point of having it in a session alongside your pressing rather than instead of it.
What it is for
Skull crushers with an ez bar are a barbell exercise targeting the triceps. Performed lying on a bench, the movement isolates the triceps by flexing and extending the elbow, building size and strength in the back of the upper arm.
Questions people ask
- What muscles do skull crushers work?
- The triceps, and only the triceps. Your shoulders hold your upper arms in place for the whole set, which is a position job rather than training. The long head of the triceps gets the most out of it when your upper arms tip back.
- Should you lower to your forehead or behind your head?
- Behind your head. Going to your forehead keeps your upper arms vertical, which stops short of the stretched position the long head benefits most from. Behind the head also tends to be the version people find easier on their elbows.
- Why do skull crushers hurt my elbows?
- The three documented causes are elbows flaring out as the bar drops, throwing the joint into a hard lockout at the top, and wrists folding back under the bar. Fix all three before deciding the exercise is the problem. If something hurts and keeps hurting, that is a question for a physiotherapist.
- Are skull crushers better than pushdowns?
- For the long head of the triceps, the more your upper arm tips back the better, and a skull crusher tips it further than a pushdown does. Training with the arm overhead grew the long head about half again as much as training with the arm at the side over 12 weeks.
- EZ bar or straight bar for skull crushers?
- Most people find the EZ bar easier on the wrists, because the bends let the hands sit at an angle instead of dead square. Nothing about what your triceps are doing changes.
- Should you lock out at the top?
- Stop just short. A hard lockout takes the load off the muscle you were training and hands it to the joint, which is neither useful nor comfortable.