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  7. Spine Lumbar - Extension

Exercise guide

Spine Lumbar - Extension

  • Beginner
  • Isolation
  • Timed hold
  • Back
  • Waist

This isolation exercise strengthens the erector spinae and trapezius muscles, improving spinal stability and posture by targeting the posterior chain.

Reviewed by the Crucible Fit team · Updated June 2026

Watch the Spine Lumbar - Extension demonstrationVideo and instructions for every movement are in the Crucible Fit app.

Muscles worked

Primary

  • Erector spinae
  • Trapezius

Secondary

  • Glutes
  • Obliques

Equipment

  • Body weight

Setup

  1. Lie face down on a flat, comfortable surface with your legs extended straight behind you.
  2. Place your hands lightly behind your head or extend them forward for more challenge.
  3. Keep your toes pointed and your forehead resting on the floor to start.

How to do it

  1. Exhale as you simultaneously lift your chest, arms, and legs a few inches off the floor by contracting your lower back and glutes.
  2. Hold the peak contraction for one second, focusing on squeezing your shoulder blades together to engage the trapezius.
  3. Inhale as you slowly lower your limbs back to the starting position in a controlled manner.
  4. Maintain a steady tempo, avoiding any jerky or momentum-based movements.

Form checklist

  • Keep your gaze toward the floor to maintain a neutral cervical spine and avoid neck strain.
  • Squeeze your glutes throughout the movement to stabilize the pelvis and protect the lower back.
  • Avoid overextending or arching excessively; lift only as high as is comfortable for your range of motion.
  • Keep your movements slow and deliberate to maximize time under tension.

Pro tips

  • Imagine someone is pulling your hands and feet in opposite directions to create length in the spine before you lift upward.
  • Focus on the mind-muscle connection by feeling the muscles along your spine 'zip up' from the tailbone to the neck as you lift.

Make it harder

  • Increase the time under tension by holding the top position for 3-5 seconds per repetition.
  • Perform 'Superman' pulses by staying in the lifted position and moving through a small, 2-inch range of motion at the top.

Frequently asked

What muscles does the spine lumbar - extension work?
The spine lumbar - extension primarily targets the erector spinae and trapezius, and also works the glutes and obliques as secondary muscles.
What equipment do you need for the spine lumbar - extension?
The spine lumbar - extension requires no equipment — just your body weight.
Is the spine lumbar - extension good for beginners?
Yes. The spine lumbar - extension is a beginner-friendly movement and a strong foundation to build on.

Related exercises

  • Around The World Superman HoldIntermediate · erector spinae, glutes, hamstrings, lats, and trapezius
  • Back LeverAdvanced · erector spinae, glutes, hamstrings, lats, pectorals, and trapezius
  • Barbell Hang Clean High PullAdvanced · erector spinae, glutes, hamstrings, lats, quadriceps, and trapezius
  • Barbell High PullIntermediate · deltoids, erector spinae, glutes, hamstrings, and trapezius

Train it with Crucible Fit.

Every movement in this library is in the app with video and instructions, ready for your own sessions on the days between Crucibles. Your first Crucible is on us.

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