# Kneeling Push Up Jack - Canonical: https://fitwill.app/exercise/8597/kneeling-push-up-jack/ - Media ID: 8597 - Primary muscle: Chest - Body part: Chest - Equipment: Body Weight - Video: https://fitwill.app/videos/8597/kneeling-push-up-jack.mp4 ## Description The Kneeling Push Up Jack is a hybrid bodyweight move that combines a kneeling push up with a jumping-jack style knee movement. You stay supported on your hands and knees the whole time, perform a push up from that shortened lever, then hop your knees out wide and back in like the lower half of a jack. Because you are on your knees instead of your toes, the load on your chest, shoulders, and arms is reduced, which frees you up to focus on speed, rhythm, and the leg drive of the jack portion. This exercise earns its place in a workout for two reasons. First, it is an accessible push up variation for anyone still building pressing strength: beginners, people returning after a layoff, or lifters finishing a chest set when a full push up is no longer possible. Second, the knee jack adds a coordination and conditioning element that a plain kneeling push up does not have. Moving the knees out and in repeatedly raises your breathing rate, challenges your hip control, and forces your trunk to stay braced while your lower body moves. The muscles doing the work are the ones you would expect from a push up — chest, triceps, and front shoulders — plus the glutes, inner thighs, and core driving the jack. Your abdominals and lower back work isometrically the entire time to keep your torso a straight line from shoulders to knees, even as your legs are hopping. That combination of upper-body pressing and continuous trunk stabilization is what makes the movement feel harder than it looks. Setup matters more here than in most floor exercises. Your hands should be under your shoulders with fingers spread, knees on a mat or other forgiving surface, and your hips extended so your body forms one clean line from head to knees. If your hips sag or pike, the push up loses its training effect and your lower back takes the stress. Before starting, squeeze your glutes and brace your abs as if you were about to be nudged in the stomach — that brace is what you protect during the jack. To execute well, lower your chest toward the floor with elbows tracking about 45 degrees from your sides, press back up, and then spring the knees out wide and back together with a small, quick hop. Keep the jack tight and controlled rather than flopping the legs out; a crisp, quiet landing on both knees at once is the sign of good technique. Breathe in on the way down, exhale as you press, and keep a steady rhythm through the jack so the set flows instead of stalling between reps. You will see this movement most often in circuit training, home workouts, and warm-ups where equipment is not available and the goal is to raise the pulse while still getting pressing volume. It also works well as a finisher after heavier pressing, letting you accumulate extra reps without needing your full bodyweight on every push up. If your knees are sensitive, pad them generously or reduce the hop of the jack to a deliberate step-out and step-in until the pattern feels smooth. ## Instructions 1. Place an exercise mat on the floor and kneel down with your knees about hip-width apart. 2. Walk your hands out until they are flat on the floor directly under your shoulders, fingers spread wide. 3. Extend your hips so your body forms a straight line from your head through your knees, with your weight on your palms and the top of your knees. 4. Squeeze your glutes and brace your abdominals to lock in that straight line before you move. 5. Lower your chest toward the floor by bending your elbows, letting them drift out to roughly 45 degrees from your torso. 6. Press through your palms to return to the starting position, exhaling as you push up. 7. From the top, hop both knees out wide to the sides at the same time, then hop them back in to hip-width, keeping the hop low and quick. 8. Land softly on both knees together and immediately reset your brace before the next push up. 9. Continue alternating one push up with one knee jack for your target number of reps. 10. When finished, sit your hips back to your heels and shake out your wrists and shoulders. ## Tips & Tricks - If your lower back arches during the jack, it usually means the brace is slipping — squeeze the glutes harder before each hop and make the jack slightly smaller. - Avoid letting your hips drift backward as you lower into the push up; the chest should travel down, not your seat back toward your heels. - Keep the jack landing quiet. A loud, heavy knee strike means you are hopping too high and jarring the knees. - Spread your fingers and grip the floor; this stabilizes the wrists, which take plenty of load in any kneeling push up variation. - Do not rush the press just because the jack is fast — the push up half still deserves a controlled two-second descent. - If your knees are uncomfortable on a hard floor, fold the mat double or use two mats; there is no benefit to training on thin padding. - Watch for elbows flaring straight out to the sides, which irritates the shoulders; aim them back at about 45 degrees instead. - If coordination falls apart mid-set, drop the jack to a slow step-out and step-in with one knee at a time until the rhythm returns. - Stop the set when your hips start sagging between reps — that sag is the first visible sign the trunk is fatiguing, not just the arms. ## Frequently Asked Questions ### What muscles does the Kneeling Push Up Jack work? The pressing portion targets the chest, triceps, and front shoulders, while the jack portion brings in the glutes, inner thighs, and hip muscles. Your abs and lower back stay engaged throughout to hold the straight line from head to knees. ### Is the Kneeling Push Up Jack good for beginners? Yes, it is one of the more beginner-friendly push up variations because kneeling shortens the lever and reduces the load. Start with a small, controlled knee jack and focus on keeping the hips level before adding speed. ### Why do my hips sag when I do the Kneeling Push Up Jack? A sagging hip usually means the glutes and abs have stopped working, which often happens when attention shifts to the jack. Squeeze your glutes before every rep and shorten the hop until you can land with your torso still flat. ### How is the Kneeling Push Up Jack different from a regular kneeling push up? The jack adds a rapid out-and-in knee hop between presses, which raises the cardiovascular demand and challenges hip control and trunk stability. A regular kneeling push up trains pressing strength only. ### Should my knees land together or apart after the jack? They should land together at about hip-width, the same position they started in, so every push up begins from a consistent setup. Landing unevenly throws off your base and twists the lower back slightly. ### What can I use instead of the Kneeling Push Up Jack? A regular kneeling push up works if you want to drop the conditioning element, while an incline push up on a bench suits anyone whose knees dislike floor work. For a similar cardio effect without the hop, alternate push ups with slow kneeling knee abductions. ### How do I protect my knees during the hop? Use a folded mat or double padding, keep the hop low rather than explosive, and land on both knees at the same time with soft, controlled contact. If kneeling still hurts, switch to a step-out version with no impact. ### Where should my hands be during the Kneeling Push Up Jack? Place your palms flat on the floor directly under your shoulders with fingers spread and weight spread across the whole hand. Hands too far forward turn the press into a shoulder-dominant movement and strain the wrists. ### How many reps should I do of the Kneeling Push Up Jack? Start with 2 to 3 sets of 8 to 12 push up plus jack combinations, resting as needed. Because the jack keeps your heart rate up, quality matters more than volume — end the set when your hips or brace start to break down.