Stability Ball Dumbbell Skull Crusher
In SetGrip: Dumbbell Skull Crusher (Stability Ball)
- Secondary muscles
- Delts
- Body part
- Upper Arms
- Position
- Supine
- Laterality
- Bilateral (both sides together)
- Category
- Strength
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Trading the bench for a stability ball means your glutes and trunk must hold a bridge while the dumbbell travels behind your head, so the set taxes far more than triceps. Loading potential drops accordingly; this earns a spot in circuit-style training or a bench-free garage setup, not as your heaviest extension of the day.
How to do the Stability Ball Dumbbell Skull Crusher
- Sit on an exercise ball with your feet flat on the ground and your knees bent at a 90-degree angle.
- Hold a dumbbell with both hands and extend your arms straight up towards the ceiling.
- Slowly lower the dumbbell behind your head, keeping your elbows close to your ears.
- Pause for a moment, then raise the dumbbell back up to the starting position.
- 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.
Sets, reps and where it fits
| Goal | Sets × reps | Rest |
|---|---|---|
| Muscle growth | 3–4 × 10–15 | 60–90 s |
| Endurance / finisher | 2–3 × 15–20 | 45 s |
| Strength | Not 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
Similar exercises
Without dumbbell
Frequently asked questions
What muscles does the Stability Ball Dumbbell Skull Crusher work?
The Stability Ball Dumbbell Skull Crusher primarily works the triceps. It also involves the delts, which assist the movement and stabilise the joints.
Is the Stability Ball Dumbbell Skull Crusher good for beginners?
It is rated intermediate, so it suits people who already train regularly. Beginners can still do the Stability Ball Dumbbell 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 Stability Ball Dumbbell Skull Crusher?
If you cannot do the Stability Ball Dumbbell Skull Crusher, try the Kneeling Bodyweight Triceps Extension, the Barbell Skull Crusher or the Seated Barbell Overhead Triceps Extension. 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 Stability Ball Dumbbell 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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More exercises
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- Behind Head Close Grip Barbell Lying Triceps Extension
- Barbell Overhead Triceps Extension
- Seated Close Grip Barbell Overhead Triceps Extension
- Behind Head Barbell Skull Crusher
- Reverse Grip Barbell Skull Crusher
Exercise data and animations are licensed ExerciseDB content used in SetGrip. This page is for general information and is not medical or coaching advice.