Core Muscles
Even though planks require the arms and toes to keep the body, the primary effort is exerted by your core muscles. Specifically, the rectus abdominis, obliques, and transverse abdominis are actively involved. The rectus abdominis, situated in the upper abdominal region, becomes visible as a “six pack” when body fat is low. Meanwhile, the transverse abdominis, positioned deeper within the abdomen, functions like a “corset,” aiding in waist cinching and stabilizing the back muscles. Additionally, both the inner and outer obliques, along with the spinal erectors, are activated during a plank. When the obliques on both sides of your body work together, they contribute significantly to stability by maintaining alignment between the ribs and hips. [1]
Back Muscles
The following muscles on the back may benefit from planks:
- Erector Spinae: extending vertically along the spine’s length, they are the most robust among the muscles involved in spine extension and rotation
- Quadratus lumborum: Positioned vertically midway along the back, starting near the pelvis, these parallel muscles stabilize and extend the lower spine while also facilitating lateral pelvic tilting
- Multifidus: These petite muscles run along the spine’s entirety, aiding in its extension and rotation
- Latissimus Dorsi: This broad, thin muscle covers a large portion of the mid to lower back. It stabilizes the lower spine during movement and initiates shoulder joint and arm movement on both sides.
