Physiotherapist Explains Why Your Plank Might Not Be Working—And How to Fix It
Planks are a go-to exercise for building core strength, but if your lower back is arching or your hips are sagging, you’re not getting the full benefit—and you might even be putting yourself at risk for injury.
According to physiotherapists, poor form is the number one reason people struggle to see results from planks. Instead of engaging the core, many lifters unknowingly shift the pressure to their lower back, shoulders, or even legs.
Why Do Hips Sag or the Lower Back Arch in a Plank?
🚫 Weak Core Muscles – If your deep core muscles aren’t strong enough, your hips naturally drop, causing the lower back to take over.
🚫 Lack of Glute and Leg Engagement – Many people forget that a plank isn’t just about the abs. If your glutes and legs are relaxed, your hips will likely sag.
🚫 Poor Body Awareness – If you don’t actively check your form, it’s easy for your lower back to arch without realizing it, especially as you get tired.
How to Fix It & Get Better Plank Results
✅ Shorter, More Effective Holds – Instead of holding a plank for minutes with poor form, focus on 20-30 seconds of perfect posture, fully engaging your core, glutes, and legs.
✅ Keep the neutral spine- Like is shown in the video above try find the middle position before going into a full plank position and then don’t allow movement from this position.
✅Vary up the core work you do- While Planks are great. Try different types of exercises also.
✅ Use a Mirror or Feedback Device – A mirror or the BackAware Belt can help ensure your spine stays neutral and prevent your lower back from arching.
Try This Plank Routine for Better Core Activation
The Bottom Line
If your lower back is arching or your hips are sagging, your plank isn’t working the way it should. By making small adjustments—engaging your glutes, tucking your pelvis, and keeping your core tight—you’ll turn a basic plank into a game-changing core exercise.
Have you been making this plank mistake? Try these tips and let us know how it feels!
