The Forearm Plank on Knees is a foundational core exercise that builds strength across the entire midsection, supports lower-back health, and trains the body to stabilize. An often-overlooked deep core muscle, the transversus abdominis, plays a major role in creating a flatter stomach and protecting the spine. When engaged properly during this plank variation, it helps reduce lower-back strain and improves overall posture.
The transversus abdominis sits beneath the belly button and acts like a natural corset for the torso. While many people focus their abdominal training on the visible rectus abdominis—the so-called “six-pack”—training the deeper low-abs and surrounding core muscles is essential for functional strength and injury prevention. The Forearm Plank on Knees targets these deeper stabilizers while also challenging the shoulders and upper back.
For people who experience back discomfort, strengthening the low abs is an effective way to add support to the lumbar spine. Traditional crunches and sit-ups primarily target the rectus abdominis and do not address spinal stabilization the way planks do. Planks, even when performed on the knees, emphasize whole-core engagement and help build the endurance needed to maintain a healthy, supported back.
This kneeling forearm plank is a great way to learn correct alignment without overstressing the lower back. By starting with the knees on the ground, you can focus on maintaining a neutral spine and activating the deep abdominals. As you gain control and endurance, you can progress to the full forearm plank on the toes for a greater challenge.
Train the forearm plank in timed intervals. Begin with short holds to ensure you can maintain perfect form: start with 10 seconds, and once you can hold that time without letting your hips sag or rise or feeling strain in the lower back, increase the duration by 10 seconds. Continue adding time gradually until you can hold a full 60 seconds with solid form. Aim to practice this exercise two to three times per week as part of a balanced core routine. For variety and progression, consider adding plank variations to your workouts.
Forearm Plank on Knees Exercise Instructions
- Begin lying on the floor with your forearms flat, making sure your elbows are aligned directly under your shoulders.
- Engage your core and lift your torso so your forearms and knees remain on the floor. Keep your body in a straight line from head to knees—avoid letting your hips sag or lift too high. Maintain steady breathing and keep the abdominals drawn in throughout the hold.
Targets: shoulders, core