Lying Barbell Tricep Extension (Skull Crusher)
The Lying Barbell Tricep Extension is a classic strength exercise that focuses on isolating and loading the triceps through controlled elbow extension.
Lying Barbell Tricep Extension (Skull Crusher)
The Lying Barbell Tricep Extension is performed on a flat bench with a barbell held above the chest. From this position, you lower the bar by bending the elbows — bringing it toward the forehead or just behind the head — then press it back up by extending the arms. The upper arms stay relatively fixed throughout, ensuring the triceps handle the vast majority of the work.
This exercise places particular emphasis on the long head of the triceps, especially when the bar travels slightly behind the head rather than directly to the forehead. The barbell allows for heavier loading than dumbbell alternatives, making it a staple in strength and hypertrophy-focused arm training. Resistance exercises targeting the elbow extensors under controlled conditions produce consistent strength adaptations across varying load and fatigue protocols (Girard et al., 2019).
Precise control around the elbow joint is essential to protect the joints and maintain constant triceps tension. Skull crushers are commonly programmed as a primary triceps builder or as accessory work following compound pressing movements in upper-body or arm-focused sessions.
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Technique and form
How to perform the Lying Barbell Tricep Extension (Skull Crusher)
- Lie flat on a bench with your feet planted firmly on the floor and grip the barbell with hands positioned shoulder-width apart using an overhand grip.
- Extend your arms straight above your chest with the barbell directly over your shoulders, keeping your wrists straight and elbows locked.
- Inhale as you slowly bend your elbows to lower the barbell toward your forehead, keeping your upper arms stationary and perpendicular to the floor.
- Maintain control of the weight throughout the descent, ensuring your elbows remain pointed toward the ceiling and don't flare outward.
- Lower the barbell until it nearly touches your forehead or the area just behind it, creating a 90-degree angle at your elbows.
- Exhale as you extend your elbows to push the barbell back up to the starting position, focusing on contracting your triceps.
- Keep your upper arms stable throughout the movement, ensuring all the work comes from your elbow extension rather than shoulder movement.
- Repeat for the prescribed number of repetitions, maintaining a controlled tempo and avoiding any jerking or momentum-based movements.
Important information
- Keep your elbows tucked in throughout the exercise to maximize tricep engagement and reduce strain on your shoulders.
- Choose an appropriate weight that allows you to maintain proper form; using too heavy a load may cause your elbows to flare out or your form to break down.
- Make sure your bench is stable and your upper back remains firmly planted on the bench throughout the entire movement.
- If you experience any elbow pain, consider using an EZ curl bar instead of a straight barbell as it places your wrists in a more neutral position.
Common Mistakes: Lying Barbell Tricep Extension (Skull Crusher)
Benefits of the Lying Barbell Tricep Extension (Skull Crusher)
Muscles Worked: Lying Barbell Tricep Extension (Skull Crusher)
The Lying Barbell Tricep Extension (Skull Crusher) is an isolation exercise that focuses your effort on the triceps. Here's a breakdown of every muscle involved.
Primary muscles
Triceps — Your triceps extend your elbows and lock out the movement. These are the main muscle doing the heavy lifting during the Lying Barbell Tricep Extension (Skull Crusher).
Risk Areas
FAQ - Lying Barbell Tricep Extension (Skull Crusher)
Skull Crushers primarily target all three heads of the triceps brachii, with particular emphasis on the long head. The exercise also engages the shoulders and chest as stabilizers, but the triceps perform the majority of the work throughout the movement.
To prevent elbow pain, avoid locking out your elbows at the top of the movement, use a weight you can control with proper form, and consider using an EZ-curl bar instead of a straight barbell. Warming up your elbows properly and ensuring your arms remain perpendicular to the floor throughout the exercise will also reduce strain.
Include Skull Crushers 1-2 times per week with at least 48 hours between sessions to allow for proper triceps recovery. They work well as part of an upper body or push day, typically performing 3-4 sets of 8-12 repetitions for hypertrophy goals.
The most common mistakes include flaring the elbows outward (keep them pointing toward the ceiling), allowing the upper arms to drift backward (maintain a perpendicular position to the floor), and using momentum by lifting the head or shoulders off the bench. Using excessive weight that compromises your form is also a frequent error.
While classified as an intermediate exercise, beginners can perform Skull Crushers by starting with very light weights or even an empty EZ-curl bar to master proper form. Consider having a spotter present and focus on controlled movement patterns before progressively adding weight as your triceps strength and coordination improve.
Scientific References
Separate and combined effects of local and systemic hypoxia in resistance exercise
Girard O, Willis SJ, Purnelle M, et al. · Eur J Appl Physiol (2019)
Sources are peer-reviewed academic publications from PubMed.
Lying Barbell Tricep Extension (Skull Crusher)
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