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  1. Home
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  3. Exercises
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  5. Core & Abs
  6. /
  7. Kneeling Hip Flexor Frontal

Exercise guide

Kneeling Hip Flexor Frontal

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

This unilateral exercise targets the quadriceps and hip flexors through a controlled lengthening phase, improving both lower body mobility and functional stability.

Reviewed by the Crucible Fit team · Updated June 2026

Watch the Kneeling Hip Flexor Frontal demonstrationVideo and instructions for every movement are in the Crucible Fit app.

Muscles worked

Primary

  • Quadriceps

Secondary

  • Abs
  • Glutes
  • Hip flexors

Equipment

  • Body weight

Setup

  1. Start in a half-kneeling position with your trailing knee on the floor and your lead foot planted firmly in front.
  2. Ensure both knees are at approximately 90-degree angles with your feet hip-width apart for balance.
  3. Maintain an upright torso with your hands on your hips and your gaze forward.

How to do it

  1. Inhale and engage your core, performing a slight posterior pelvic tilt (tuck your tailbone) to stabilize the hips.
  2. Exhale as you slowly shift your weight forward into the front leg, keeping your torso vertical and your trailing glute squeezed.
  3. Inhale as you use the lead leg to push your body back to the starting 90-90 position.
  4. Perform the movement at a controlled 2-1-2 tempo (2 seconds forward, 1 second hold, 2 seconds back).

Form checklist

  • Keep your chest tall and avoid leaning forward at the hips.
  • Ensure the front knee stays aligned with the middle of your foot, not caving inward.
  • Maintain a tight core to prevent your lower back from arching excessively.
  • Keep the trailing glute engaged throughout the entire range of motion.

Pro tips

  • Squeeze the glute of the kneeling leg as hard as possible to maximize the stretch and engagement of the quadriceps through reciprocal inhibition.
  • Think about driving your kneeling shin into the floor to create more stability and tension in the target muscles.

Make it harder

  • Elevate the rear foot on a bench or block to increase the stretch on the quadriceps (Couch Stretch variation).
  • Reach both arms overhead during the forward shift to increase the tension through the entire anterior chain.

Frequently asked

What muscles does the kneeling hip flexor frontal work?
The kneeling hip flexor frontal primarily targets the quadriceps, and also works the abs, glutes, and hip flexors as secondary muscles.
What equipment do you need for the kneeling hip flexor frontal?
The kneeling hip flexor frontal requires no equipment — just your body weight.
Is the kneeling hip flexor frontal good for beginners?
The kneeling hip flexor frontal is rated intermediate. Build a base with simpler variations first, then progress to it with light load and strict form.

Related exercises

  • 90 To 90Beginner · abs, glutes, obliques, and quadriceps
  • 90 To 90 SwitchIntermediate · abs, glutes, obliques, and quadriceps
  • Air Punches MarchBeginner · calves, pectorals, and quadriceps
  • All Fours Squat StretchBeginner · 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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