Plank Jack
Plank Jack Exercise Description
Plank Jack is a dynamic high-plank variation that challenges trunk stability while the legs hop out and in, similar to a jumping jack. The primary focus is the anterior core (rectus abdominis and obliques), with the transverse abdominis contributing to spinal and pelvic control. Shoulders and scapulae work hard to stabilize (serratus anterior, rotator cuff), while the glutes and quadriceps maintain a straight body line. The outward and inward foot hops recruit the hip abductors and adductors and add a low-impact plyometric demand to the lower body. The goal is to keep a neutral spine, level hips, and steady ribcage over the pelvis despite the leg movement. Done well, it trains anti-extension and anti-rotation control in a full-body, closed-chain position using only body weight.
- Muscle Groups: Abs, Core, Waist
- Target Muscles: Rectus Abdominis
- Assisting Muscles: External Obliques, Internal Obliques
- Stabilizing Muscles: Gluteus Maximus, Serratus Anterior, Subscapularis, Transversus Abdominis, Vastus Lateralis
- Body Area: Upper Body
- Body Parts: Core, Torso
- Body Surface: Front
- Body Symmetry: Bilateral
- Equipment: Bodyweight
- Exercise Patterns: Other
- Exercise Type: Strength
- Functional Grouping: Trunk Flexors
- Joint Involvement: Multi-joint
- Muscle Location: Stomach
- Movement Direction: Rotational
- Muscle Position: Anterior
- Gender: Female
How To Do The Plank Jack Exercise
‘- Start in a high plank: hands under shoulders, fingers spread, wrists neutral; legs together on toes.
– Press the floor away to create shoulder stability; keep shoulder blades stable (slight protraction), neck neutral, gaze just in front of hands.
– Brace the abdominal wall and lightly squeeze glutes to keep ribs stacked over pelvis and the spine neutral.
– Keep hips level—avoid sagging (lumbar extension) or piking.
– Hop both feet out to about shoulder-width; land softly on the balls of the feet with knees slightly flexed.
– Hop feet back together under control; minimize trunk sway and keep shoulders over wrists.
– Breathe continuously; avoid holding your breath.
– Quality checks each rep: quiet landings, elbows not locked, core braced, pelvis square to the floor.
– If form wavers, pause, reset the plank, or switch to a lower-impact option (alternating step-outs or hands elevated on a stable bench).
Plank Jack Tips
‘- Set up with hands directly under shoulders, fingers spread, and wrists neutral before you start hopping.
– Actively press the floor away to stabilize your shoulders and keep a slight shoulder blade protraction.
– Keep your neck neutral with your gaze just in front of your hands, not forward or between your feet.
– Brace your abdominal wall and lightly squeeze your glutes to keep ribs stacked over your pelvis.
– Maintain a neutral spine with level hips; avoid letting your hips sag or pike up.
– Hop both feet out to about shoulder-width and land softly on the balls of your feet with knees slightly bent.
– Hop your feet back together under control, minimizing trunk sway and keeping your shoulders over your wrists.
– Breathe continuously throughout the set instead of holding your breath.
– On each rep, check for quiet landings, unlocked elbows, a braced core, and a pelvis square to the floor.
– If your form starts to break down, pause to reset the plank or switch to alternating step-outs or an elevated-hand version.
Plank Jack Beginner Introduction
Plank Jack is a lively, full-body bodyweight exercise built around a straight-arm plank position with jumping-jack-style foot movement. While the upper body stays planted through the hands, the legs spring apart and together, giving the lower body a gentle jumping challenge without leaving the floor completely. Throughout the movement, the abs, deep abs, and side abs work together with the lower back muscles to hold the middle of the body steady, while the shoulders and muscles around the rib cage provide a firm base up top.
The glutes and quads help keep the body aligned in a long, straight line, so the lower half does the hopping without throwing the rest of the body off. As the feet move wider and then come back in, the hips and inner thighs contribute to controlling that motion. The main theme of this exercise is resisting unwanted arching, twisting, or sinking through the center of the body, training strong, steady posture in a supported, ground-based position.