Master correct SET UP of the exercise, first and foremost.
Focus on good integration and connection. Radiate tension throughout your body. That radiation of stiffness and tension is what will take stress OFF of the hamstrings, which can take the brunt of the stress if we allow them to.
Should This Be Moving?
One of the benefits of this exercise is that it will give you an opportunity to apply many of the skills you’ve been learning to this point, specifically the HIP HINGE, as you raise your body up into the plank from a seated position on the floor. The goal here is simple and very important:
Think of your hip joints like skewers. Move through those “skewers” while maintaining integrity and stiffness within your trunk, e.g. your core.
One of the most important benefits of learning core stability and building strength of the core is that we can then, in the process, move MORE through our hips. The hips become the powerhouse. The hips are built to be one of our prime movers. The hips are where we transfer power above and below. The trunk/core is our foundation. Practice these elements as you work on the posterior plank!
The posterior plank can be a very fatiguing exercise when you do it to the “max,” or when attempting to hold isometrically (without moving) for a sustained period. I do not recommend you start this way.
As mentioned, there are THREE progressive variations that are presented in the video. Follow the guidance and approach this in a smart way.
Move into position from a seated position via a good quality HINGE at the hip joints.
Radiate tension throughout your body in order to reduce stress in any one area, which could result in injury if you push too hard, too soon.
Make sure to keep your back and core fully engaged in order to provide a good stable support for your body and take stress OFF of the low back.
Listen to the instructional video for the guidance you need. Scale it appropriately. A little goes a long way. Train smart.