Exercise guide
Plank Knee Tap
- Intermediate
- Compound
- Timed hold
- Lower arms
- Lower legs
- Shoulders
- Upper arms
- Upper legs
- Waist
The Plank Knee Tap is a dynamic core stability exercise that builds anti-rotational strength and shoulder stability by challenging your balance. It targets the rectus abdominis and obliques while requiring significant isometric tension from the deltoids and quadriceps.
Reviewed by the Crucible Fit team · Updated June 2026
Muscles worked
Setup
- Start in a high plank position with your hands directly under your shoulders and feet hip-width apart.
- Engage your core, squeeze your glutes, and tuck your pelvis slightly to create a straight line from head to heels.
- Distribute your weight evenly across your palms and toes, keeping your gaze slightly ahead of your hands.
How to do it
- Exhale and shift your weight slightly onto one hand while lifting the opposite knee toward your chest.
- Simultaneously reach back with the free hand to tap the rising knee, focusing on keeping your hips perfectly level.
- Inhale as you slowly return your hand and foot to the starting plank position with total control.
- Repeat the movement on the opposite side, alternating back and forth at a steady, controlled tempo.
Form checklist
- Keep your hips square to the floor; do not allow them to rotate or tilt as you lift your limbs.
- Maintain a flat back and avoid letting your lower back sag or your hips pike upward.
- Keep the supporting arm locked and push 'through the floor' to stabilize the shoulder.
- Ensure the movement is slow and deliberate to maximize core engagement.
Pro tips
- Imagine a glass of water resting on your lower back; your goal is to move without spilling a single drop.
- Focus on the mind-muscle connection by actively 'crunching' your lower abs as the knee drives forward.
Make it harder
- Increase the time under tension by holding the knee-to-hand tap for 2-3 seconds before returning to the plank.
- Perform the exercise with your feet closer together to decrease your base of support and increase the stability challenge.
Frequently asked
- What muscles does the plank knee tap work?
- The plank knee tap primarily targets the abs, deltoids, and obliques, and also works the rhomboids, serratus anterior, and trapezius as secondary muscles.
- What equipment do you need for the plank knee tap?
- The plank knee tap requires no equipment — just your body weight.
- Is the plank knee tap good for beginners?
- The plank knee tap is rated intermediate. Build a base with simpler variations first, then progress to it with light load and strict form.