EZ-Bar Skull Crushers: How To, Muscles Worked & Common Mistakes

EZ-bar skull crushers are one of the best exercises for building triceps mass — particularly the long head, which is the largest of the three triceps heads and the one most responsible for overall arm size. The lying position stretches the long head through a greater range of motion than most standing or seated triceps exercises, making skull crushers especially effective for adding size to the back of the arm.

The name is dramatic — but as long as you use controlled form and an appropriate weight, this is a safe and highly productive exercise.

Why EZ-Bar vs. Straight Bar

Skull crushers can be done with a straight barbell or an EZ curl bar — and the EZ bar is almost always the better choice:

• The straight bar requires full wrist supination which puts significant stress on the wrists and elbows over time
• The EZ bar’s angled grips put your wrists in a more natural, semi-neutral position that’s much more comfortable on the joints for most people
• Both target the triceps equally effectively — the EZ bar just does it with less joint stress

Unless you have a specific reason to use the straight bar, the EZ bar is the recommended option here. Check out our Barbell Triceps Extension page for the straight bar standing version.

EZ-Bar Skull Crushers – Muscles Worked

Primary muscles:

• Triceps brachii (long head) — the largest triceps head, heavily stretched and loaded in the lowered position due to the overhead arm angle. This is what makes skull crushers so effective for building overall triceps size.
• Triceps brachii (lateral head) — the outer head, heavily involved throughout the extension
• Triceps brachii (medial head) — the inner head, assists throughout the movement

Secondary muscles:

• Anconeus — assists with elbow extension at lockout
• Core — stabilizes your torso on the bench throughout the set

How to Perform EZ-Bar Skull Crushers

1. Lie flat on a bench with your feet flat on the floor. Have a spotter hand you the EZ bar, or carefully press it up from your chest to get it into position.
2. Hold the EZ bar with an overhand grip on the inner angled handles, arms extended directly above your chest — not above your face. This is your starting position.
3. Keep your upper arms completely still — they should not move throughout the entire exercise. Only your forearms move.
4. Slowly lower the bar by bending your elbows, bringing the bar down toward your forehead — or slightly past it toward the top of your head for a deeper long head stretch.
5. Stop just before the bar touches your head and reverse the motion.
6. Extend your elbows to press the bar back to the starting position, squeezing your triceps at full extension.
7. Repeat for your desired reps.

EZ-Bar Skull Crushers Pro tip: As you lower the bar, allow your upper arms to angle back very slightly — tilting backward about 5–10 degrees from vertical. This keeps the long head under greater stretch throughout the lowering phase and is a technique used by many experienced lifters to increase the effectiveness of the exercise.

EZ-Bar Skull Crushers – Sets & Reps

EZ-Bar Skull Crushers – Common Mistakes to Avoid

1. Upper arms moving during the exercise This is the most important cue. Your upper arms should be fixed in position throughout every rep — only your forearms move. If your upper arms are swinging back and forth, you’ve turned this into a partial press rather than a triceps isolation exercise.

2. Lowering too fast This is an exercise where the bar is travelling toward your face — controlling the descent is both a safety and an effectiveness issue. Lower slowly and deliberately over 2–3 seconds every rep. Never rush this exercise.

3. Elbows flaring outward Your elbows should stay pointing upward and relatively narrow throughout the movement. Letting them flare wide reduces triceps activation and puts unnecessary stress on the elbow joints. Keep them tracking straight up throughout.

4. Starting with the bar above your face The bar should start directly above your chest — not above your forehead or face. Starting above the chest means the natural lowering arc of the movement brings the bar toward your forehead, which is exactly where it should go.

5. Going too heavy Skull crushers with too much weight lead to upper arm movement, elbow flare, and rushed reps — all of which both reduce effectiveness and increase injury risk. Use a weight where you can perform every rep with perfectly still upper arms and controlled form.

Superset Tip: EZ-bar Skull Crushers into Close Grip Press

One of the most popular and effective triceps supersets is moving directly from skull crushers into close grip bench press using the same EZ bar without resting. By the time your triceps are too fatigued to complete skull crushers with strict form, your chest and shoulders can still help push through close grip presses — meaning your triceps get more total work than they could from either exercise alone. It’s a brutal finisher that experienced lifters swear by.

Where It Fits in Your Workout

EZ-bar skull crushers are a compound triceps exercise that allows you to load heavier than most isolation movements. They work best near the start of your triceps session after any overhead pressing work — before lighter isolation exercises like triceps pushdowns and triceps kickbacks. Because of the elbow joint stress involved, they’re best done when your joints are warmed up but your muscles are still fresh.