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  3. Exercises
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  5. Core & Abs
  6. /
  7. Bent Knee Back To Side Kick

Exercise guide

Bent Knee Back To Side Kick

  • Intermediate
  • Compound
  • Rep-based
  • Lower legs
  • Waist

This exercise combines a donkey kick with a lateral hip abduction to target the glutes and lower back while challenging core stability and hip mobility. It is highly effective for strengthening the posterior chain and engaging the obliques through multi-planar movement.

Reviewed by the Crucible Fit team · Updated June 2026

Watch the Bent Knee Back To Side Kick demonstrationVideo and instructions for every movement are in the Crucible Fit app.

Muscles worked

Primary

  • Erector spinae
  • Glutes
  • Hamstrings

Secondary

  • Abs

Equipment

  • Body weight

Setup

  1. Start on all fours in a quadruped position with your hands directly under your shoulders and knees under your hips.
  2. Engage your core to maintain a neutral spine, ensuring your back is flat like a tabletop.
  3. Distribute your weight evenly between your hands and the stationary knee.

How to do it

  1. Keeping your knee bent at 90 degrees, exhale and lift one leg back and upward until your thigh is parallel to the floor, squeezing the glute at the top.
  2. Without lowering the leg, rotate your hip to bring the bent knee out to the side in a controlled lateral arc (similar to a fire hydrant move).
  3. Inhale as you reverse the arc back to the center and lower the knee toward the starting position without letting it touch the floor.
  4. Maintain a slow, controlled tempo, focusing on the transition between the back and side phases.

Form checklist

  • Keep your core braced to prevent your lower back from arching during the back kick.
  • Ensure your hips stay level and square to the floor; avoid tilting your pelvis to the side.
  • Keep your neck neutral by looking at a point on the floor about 6 inches in front of your hands.
  • Maintain a constant 90-degree bend in the working knee throughout the entire movement.

Pro tips

  • Imagine you are drawing a wide semi-circle with your knee to maximize the engagement of the glute medius and obliques.
  • At the peak of the back kick, pause for one second to maximize the mind-muscle connection with the erector spinae and gluteus maximus.

Make it harder

  • Place a light mini-band just above your knees to add constant tension and resistance to both the posterior and lateral movements.
  • Perform the movement with a 3-second eccentric (lowering) phase to increase time under tension for the hamstrings and glutes.

Frequently asked

What muscles does the bent knee back to side kick work?
The bent knee back to side kick primarily targets the erector spinae, glutes, and hamstrings, and also works the abs as secondary muscles.
What equipment do you need for the bent knee back to side kick?
The bent knee back to side kick requires no equipment — just your body weight.
Is the bent knee back to side kick good for beginners?
The bent knee back to side kick is rated intermediate. Build a base with simpler variations first, then progress to it with light load and strict form.

Related exercises

  • Around The World Superman HoldIntermediate · erector spinae, glutes, hamstrings, lats, and trapezius
  • Barbell Clean And JerkAdvanced · deltoids, erector spinae, glutes, hamstrings, quadriceps, and trapezius
  • Barbell Clean And PressAdvanced · deltoids, erector spinae, glutes, hamstrings, quadriceps, and triceps
  • Barbell Hang CleanAdvanced · erector spinae, glutes, hamstrings, hip flexors, and quadriceps

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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