Dumbbell Lying Triceps Extension Skull Crusher

Dumbbell Lying Triceps Extension Skull Crusher Exercise Description

The dumbbell lying triceps extension (“skull crusher”) is an upper-arm isolation exercise that emphasizes elbow extension to target the triceps brachii (long, lateral, and medial heads). Performed supine on a bench, it challenges the triceps through a long lever while the shoulder and scapular musculature act primarily to stabilize. Keeping the upper arms relatively fixed limits shoulder motion so the triceps do the work. A neutral wrist and controlled range protect joint alignment and improve force transfer through the forearm into the dumbbells. Expect the highest tension near the bottom of the movement as the elbows flex and the lever arm increases; smooth, deliberate reps help maintain control around the head. This variation accommodates either neutral or pronated grips; many lifters choose a neutral grip for comfortable wrist and shoulder alignment. Consistent setup—neutral spine, lightly retracted and depressed scapulae, elbows pointing generally toward the ceiling—helps keep the movement precise and triceps-focused.

Muscle Groups: Triceps
Target Muscles: Triceps Brachii - Long Head
Assisting Muscles: Triceps Brachii - Lateral Head, Triceps Brachii - Medial Head
Stabilizing Muscles: Infraspinatus, Subscapularis, Supraspinatus, Teres Minor, Trapezius - Middle Fibers
Body Area: Upper Body
Body Parts: Arms, Upper Arms
Body Surface: Back
Body Symmetry: Bilateral
Equipment: Dumbbell
Exercise Patterns: Other
Exercise Type: Strength
Functional Grouping: Elbow Extensors
Joint Involvement: Single-joint
Muscle Location: Inner Tricep
Movement Direction: Other
Muscle Position: Posterior
Gender: Male

How To Do The Dumbbell Lying Triceps Extension Skull Crusher Exercise

‘- Lie supine on a flat bench with feet planted and head supported; maintain a neutral spine and ribs down.
– Hold two dumbbells above the chest with a neutral grip; wrists straight, stacked over elbows.
– Set the shoulders: lightly retract and depress the scapulae; keep upper arms close to, not pinned against, the torso.
– Start with elbows extended and pointing up; upper arms stay mostly vertical or slightly angled toward the head.
– Inhale. Bend only at the elbows to lower the dumbbells toward the sides of your forehead/temples, keeping wrists neutral.
– Stop just before the dumbbells touch your head; forearms align under the weights without breaking at the wrist.
– Exhale. Extend the elbows along the same path until the arms are straight without forcefully locking out.
– Keep shoulders quiet; avoid flaring the elbows wide or letting upper arms drift.
– Control the eccentric and maintain clearance from the head throughout.
– To finish or set down, bring dumbbells to the chest, then sit up before lowering them safely.

Dumbbell Lying Triceps Extension Skull Crusher Tips

‘- Plant your feet and keep your head supported to help maintain a neutral spine with ribs down.
– Keep your wrists straight and stacked directly over your elbows when holding the dumbbells.
– Lightly retract and depress your shoulder blades to stabilize the shoulders before you start.
– Keep your upper arms close to your torso without pinning them tightly against your sides.
– Aim your elbows generally toward the ceiling and keep your upper arms mostly vertical or slightly angled toward your head.
– Bend only at the elbows to lower the dumbbells toward the sides of your forehead or temples, keeping a neutral wrist.
– Stop the descent just before the dumbbells touch your head so the forearms stay aligned under the weights.
– Extend your elbows along the same path and straighten your arms without forcefully locking out.
– Keep the shoulders quiet and avoid letting your elbows flare wide or your upper arms drift as you move.
– Control the lowering phase and maintain clear space around your head throughout each rep.

Dumbbell Lying Triceps Extension Skull Crusher Beginner Introduction

The dumbbell lying triceps extension (“skull crusher”) is a classic upper‑arm move that centers on bending and straightening the elbows while the rest of the body stays steady on a bench. With the lifter on their back and the weights held above the chest, the motion sends the dumbbells in an arc toward the head and back up again. Because the upper arms stay mostly in one place, the triceps handle most of the work, while the shoulders and upper back mainly act as anchors.

This exercise highlights control and accuracy more than brute force. The long distance between the elbows and the dumbbells creates a strong pull on the triceps, especially when the elbows are most bent near the bottom of the path. A straight line from hand to forearm improves how force moves into the weights and can feel easier on the wrists. Grip can be adjusted, with many lifters favoring palms facing each other for a comfortable position at the shoulders. Smooth, deliberate repetitions and consistent body placement encourage a focused, arm‑isolating feel often sought in muscle‑building routines.