Jack Plank
Jack Plank Exercise Description
The Jack Plank (also called a plank jack) is a dynamic plank variation that challenges trunk stability while the legs hop in and out. The primary focus is the core—especially the rectus abdominis, transverse abdominis, and obliques—working to resist lumbar extension and rotation. The shoulders, chest, triceps, and scapular stabilizers (including the serratus anterior) support the upper body, while the hips, quadriceps, and calves handle the lower-body hopping. The goal is to keep a neutral spine and level pelvis as the movement occurs at the hips and ankles. This bodyweight drill builds control, coordination, and endurance of the anterior core and shoulder girdle when performed with smooth, controlled landings and steady breathing.
- Muscle Groups: Abs, Core, Waist
- Target Muscles: Rectus Abdominis, Transversus Abdominis
- Assisting Muscles: External Obliques, Internal Obliques
- Stabilizing Muscles: Deltoid - Anterior, Gluteus Maximus, Pectoralis Major - Sternal Head, Serratus Anterior, Triceps Brachii - Medial Head
- Body Area: Upper Body
- Body Parts: Core, Torso
- Body Surface: Front
- Body Symmetry: Bilateral
- Equipment: Bodyweight
- Exercise Patterns: Other
- Exercise Type: Strength
- Functional Grouping: Core Stabilizers, Trunk Flexors
- Joint Involvement: Multi-joint
- Muscle Location: Deep Abs, Stomach
- Movement Direction: Rotational
- Muscle Position: Anterior
- Gender: Female
How To Do The Jack Plank Exercise
‘- Start in a high plank: hands under shoulders, fingers spread, elbows softly extended.
– Press the floor away to create active shoulder stability; keep shoulder blades flush with the rib cage.
– Form a straight line from head to heels; ribs down, light abdominal brace, and glutes engaged to hold a neutral pelvis.
– Bring feet together; balance on the balls of the feet with heels slightly elevated.
– Hop both feet out to just wider than hip-width; land softly without letting the hips drop or pike.
– Hop both feet back together, keeping the pelvis level and minimizing trunk sway.
– Maintain a quiet, controlled rhythm; movement happens at the hips, not the low back.
– Keep your gaze slightly ahead of your hands to maintain a neutral neck.
– Breathe continuously—avoid holding your breath.
– For lower impact, step one foot out at a time instead of hopping.
– If wrists are sensitive, perform on forearms with elbows under shoulders while maintaining all other cues.
Jack Plank Tips
‘- Place hands directly under shoulders with fingers spread and elbows softly extended.
– Actively press the floor away to keep the shoulder blades flush with the rib cage.
– Maintain a straight line from head to heels with ribs down and a light abdominal brace.
– Engage the glutes to help hold a neutral pelvis.
– Start with feet together, balancing on the balls of the feet with heels slightly elevated.
– Hop the feet out just wider than hip-width and land softly without letting the hips drop or pike.
– Hop the feet back together while keeping the pelvis level and minimizing trunk sway.
– Focus on movement at the hips and ankles, not through the low back.
– Keep your gaze slightly ahead of your hands to maintain a neutral neck.
– Breathe continuously throughout the set instead of holding your breath.
– Use a step-out (one foot at a time) instead of hopping for a lower-impact option.
– If wrists are sensitive, perform the exercise on your forearms with elbows under shoulders while keeping all other cues the same.
Jack Plank Beginner Introduction
The Jack Plank (also called a plank jack) is a fast-paced twist on a traditional plank that mixes core stability with light jumping. The upper body stays in a strong plank position while the legs jump apart and together, similar to a jumping jack on the floor. Throughout the movement, the midsection works hard to limit arching or twisting through the lower back, so the motion mainly comes from the hips and ankles rather than the spine.
This bodyweight exercise targets the core—especially the abs and side abs—while the shoulders, chest, arms, and muscles around the shoulder blades brace to hold the top of the plank. The hips, front thighs, and calves support the hopping action underneath. The emphasis is on smooth landings, steady breathing, and a stable, aligned torso as the legs move. A lower-impact option uses alternating step-outs instead of jumps, and some people shift onto their forearms when the straight-arm position is uncomfortable for the wrists, while still keeping the same overall pattern.