Strength Training

Lying Tricep Extension: Understanding, Execution, Variations, and Safety

By Hart 7 min read

The lying tricep extension, commonly known as a skullcrusher, is an isolation exercise performed supine on a bench that targets all three heads of the triceps brachii for hypertrophy and increased pressing strength.

How to Do a Lying Tricep Extension?

The lying tricep extension, commonly known as a skullcrusher, is an isolation exercise designed to effectively target and develop all three heads of the triceps brachii, performed while lying supine on a bench, typically with a barbell, EZ curl bar, or dumbbells.

Understanding the Lying Tricep Extension

The lying tricep extension is a foundational exercise for triceps development, renowned for its ability to promote hypertrophy and strengthen the posterior upper arm. It isolates the triceps by focusing on elbow extension while minimizing shoulder involvement.

  • Muscles Worked:
    • Primary Mover: Triceps Brachii (Long Head, Lateral Head, Medial Head)
    • Synergist: Anconeus
    • Stabilizers: Deltoids (anterior), Pectoralis Major, Rotator Cuff muscles, Forearm flexors (grip)
  • Benefits:
    • Triceps Hypertrophy: Directly targets all three heads, promoting significant muscle growth.
    • Increased Pressing Strength: Stronger triceps are crucial for compound pushing movements like bench press and overhead press.
    • Improved Elbow Joint Stability: Strengthening the muscles around the elbow can contribute to joint health.
    • Enhanced Arm Aesthetics: Contributes to a well-defined and powerful-looking arm, making up approximately two-thirds of the upper arm's mass.

Step-by-Step Execution Guide

Proper form is paramount to maximize effectiveness and minimize injury risk.

  • Equipment:
    • Flat Bench: Essential for supine position.
    • Barbell: A straight barbell offers a pronated grip, while an EZ curl bar is often preferred for comfort, reducing wrist strain due to its semi-supinated grip.
    • Dumbbells: Allows for unilateral work and a more natural range of motion for some individuals.
  • Setup:
    1. Positioning: Lie supine (on your back) on a flat weight bench. Ensure your head, upper back, and glutes are firmly pressed against the bench.
    2. Foot Placement: Plant your feet flat on the floor, roughly shoulder-width apart, to maintain stability and a stable base.
    3. Grip (Barbell/EZ Bar): Grasp the barbell with an overhand (pronated) grip, slightly narrower than shoulder-width. For an EZ bar, use the inner angled grips. Ensure your thumbs are wrapped securely around the bar.
    4. Starting Position: Carefully lift the weight off the rack (or have a spotter assist) and extend your arms straight up, locking your elbows. The weight should be directly over your chest or just slightly behind it, perpendicular to the floor. Your palms should face towards your feet.
  • Execution (Concentric & Eccentric Phases):
    1. Lowering Phase (Eccentric): Inhale deeply. Slowly and with control, begin to lower the weight by hinging only at your elbows. Your upper arms should remain relatively stationary and perpendicular to the floor. The bar should descend towards your forehead or slightly behind your head (often referred to as the "skullcrusher" path, though lowering slightly behind the head can be safer for some).
    2. Extension Phase (Concentric): Exhale as you powerfully contract your triceps to extend your forearms, pushing the weight back up to the starting position. Focus on "squeezing" the triceps at the top of the movement.
    3. Repetition: Maintain tension throughout the movement. Avoid locking out the elbows aggressively at the top to protect the joint, but aim for full extension.
  • Breathing: Inhale during the eccentric (lowering) phase, and exhale during the concentric (lifting) phase.

Common Variations

To keep training dynamic and address individual preferences or limitations, several variations exist:

  • EZ Bar Lying Tricep Extension: The most common variation, the EZ curl bar's curved shape reduces wrist strain compared to a straight bar, making it more comfortable for many.
  • Dumbbell Lying Tricep Extension: Using dumbbells allows for a more natural, independent range of motion for each arm. It can also help identify and correct muscular imbalances. Dumbbells can be lowered on either side of the head or simultaneously behind the head.
  • Incline Lying Tricep Extension: Performed on an incline bench, this variation places a slightly different emphasis on the triceps, potentially increasing the stretch on the long head due to greater shoulder flexion.
  • Decline Lying Tricep Extension: Executed on a decline bench, this variation is less common but can alter the angle of resistance, though its specific advantages over flat or incline are debated.
  • Cable Lying Tricep Extension: Using a cable machine provides constant tension throughout the entire range of motion, which can be beneficial for muscle activation.

Form Cues and Common Mistakes

Mastering the lying tricep extension requires attention to detail.

  • Form Cues:
    • Elbow Position: Keep your elbows relatively fixed and pointing straight up throughout the movement. Avoid letting them flare out excessively.
    • Controlled Movement: Execute each rep with a slow, controlled tempo. Avoid using momentum or bouncing the weight.
    • Full Range of Motion: Aim for full elbow extension at the top and a deep stretch at the bottom without compromising joint integrity.
    • Scapular Stability: Keep your shoulders pinned back and down on the bench to maintain stability and prevent unnecessary shoulder involvement.
    • Upper Arm Angle: Maintain your upper arms perpendicular to the floor. Only your forearms should move.
  • Common Mistakes:
    • Flaring Elbows: Allowing elbows to drift outwards reduces triceps isolation and can place undue stress on the shoulder joints.
    • Using Too Much Weight: This often leads to poor form, where the shoulders or chest take over, negating the triceps isolation and increasing injury risk.
    • Lack of Control/Momentum: Bouncing the weight or using jerky movements reduces muscle tension and increases the risk of injury, particularly to the elbows.
    • Not Fully Extending: Failing to fully extend the elbows at the top limits the triceps' peak contraction.
    • Lowering to the Nose/Forehead: While called "skullcrushers," lowering the bar too directly to the face can be dangerous. Aim for a path slightly behind the head for safer execution and a greater stretch.

Safety Considerations and Injury Prevention

Prioritizing safety is crucial for a sustainable and effective training regimen.

  • Spotter: When lifting heavier loads, especially with a barbell, a spotter is highly recommended to assist with racking/unracking and to help if you fail a rep.
  • Warm-up: Always perform a thorough warm-up, including dynamic stretches and light sets of the exercise, to prepare your elbow joints and triceps for the work ahead.
  • Listen to Your Body: If you experience any sharp pain in your elbows, wrists, or shoulders, stop the exercise immediately.
  • Proper Weight Selection: Choose a weight that allows you to maintain perfect form for your target rep range. Ego lifting significantly increases injury risk.
  • Bench Stability: Ensure the bench is stable and secure before lying down and performing the exercise.

Integrating into Your Training Program

The lying tricep extension is a versatile exercise that can be incorporated into various training splits.

  • Rep Range: For hypertrophy, aim for 8-15 repetitions per set. For strength, lower rep ranges (e.g., 5-8) can be used with heavier weight, but be extra cautious with form.
  • Placement: It's often performed after compound pressing movements (e.g., bench press, overhead press) as an accessory exercise to further fatigue the triceps. It can also be a primary exercise on an "arm day" or "push day."
  • Frequency: Depending on your overall training volume and recovery capacity, 1-3 times per week is common.

Conclusion

The lying tricep extension is an indispensable exercise for anyone serious about developing strong, well-defined triceps. By understanding its biomechanics, adhering to precise form, and incorporating it intelligently into your training, you can unlock significant gains in both muscle size and functional pressing strength. Always prioritize safety and listen to your body to ensure a long and effective training journey.

Key Takeaways

  • Lying tricep extensions (skullcrushers) are an isolation exercise primarily targeting all three heads of the triceps brachii for muscle growth and increased pressing strength.
  • Proper form involves lying supine on a bench, keeping upper arms stationary and perpendicular to the floor, hinging only at the elbows, and lowering the weight towards the forehead or slightly behind the head.
  • Variations like EZ bar, dumbbell, incline, decline, and cable extensions offer different angles and comfort levels to suit individual preferences and training goals.
  • Common mistakes include flaring elbows, using excessive weight, lack of control, and not achieving full extension, all of which compromise effectiveness and increase injury risk.
  • Safety precautions such as using a spotter, performing a thorough warm-up, listening to your body, and selecting appropriate weight are crucial for preventing injuries and ensuring a sustainable training regimen.

Frequently Asked Questions

What muscles does the lying tricep extension primarily work?

The lying tricep extension primarily targets all three heads of the triceps brachii, with the anconeus acting as a synergist.

What equipment is needed for a lying tricep extension?

Essential equipment for the lying tricep extension includes a flat bench and a weight implement such as a barbell, an EZ curl bar, or dumbbells.

What are common mistakes to avoid when performing lying tricep extensions?

Common mistakes to avoid include flaring elbows outwards, using excessive weight, performing the movement without control or momentum, failing to fully extend the elbows, and lowering the bar too directly to the face.

What are the benefits of incorporating lying tricep extensions into a workout?

Benefits of incorporating lying tricep extensions include significant triceps hypertrophy, increased strength in compound pressing movements, improved elbow joint stability, and enhanced upper arm aesthetics.

How should I breathe during the lying tricep extension?

During the lying tricep extension, you should inhale deeply as you lower the weight (eccentric phase) and exhale as you powerfully extend your forearms to push the weight back up (concentric phase).