If you’re recovering from a recent back injury or are just starting core training, it’s important to choose exercises that not only strengthen your core but also minimize the risk of re-injury. In this post, I’ll break down some of the best core exercises for those in the subacute phase of recovery, and why they are effective, based on the latest biomechanics research.
Awhile back I attended a seminar by Dr. Craig Liebenson, a well known chiropractor. One key takeaway was how important it is to focus on exercises that balance muscle activation while minimizing compressive and shear loads on the spine—especially in the early stages of recovery. Exercises that place too much load on the spine can slow recovery or, worse, lead to re-aggravation of the injury.
Understanding Spinal Load: Compression vs. Shear
When starting your core rehabilitation, it’s crucial to understand the difference between compression and shear forces:
- Compression forces occur when weight is vertically applied to the spine, such as when you lift or carry objects.
- Shear forces are horizontal stresses that occur during movements like twisting or bending.
Research shows that shear forces are more stressful to the spine than compression, especially in regions like the L5-S1 disc. Minimizing both types of stress during recovery exercises is key to minimize aggravation early on in the rehabilitation of back pain (Gallagher & Marras, 2012).
Safe Core Exercises to Minimize Spinal Load During the Subacute Phase
Let’s dive into some of the best core exercises that minimize stress on the spine while effectively strengthening your core. I’ll compare these to more traditional exercises to show why they’re safer for you in the subacute phase of recovery.
1. McGill Crunch vs. Sit-ups
The McGill Crunch is a modified version of the traditional crunch, designed to limit lumbar flexion and reduce compressive forces on the spine. Studies show that this exercise places 2000 N of compressive load on the spine, while the standard bent-knee sit-up generates 3350 N, and straight-leg sit-ups produce 3500 N of compressive force. If you perform sit-ups on a stability ball, the load can increase to 4000 N (Axler & McGill, 1997).
Takeaway: Stick to McGill Crunches during early rehab to avoid excess spinal load.
2. Side Plank (Knees) vs. Side Plank (Feet)
The side plank is another great exercise for core stability, targeting the obliques and deep stabilizers. The full side plank on the feet generates about 2600 N of compressive load on the spine, while performing the same exercise on the knees reduces that to 2000 N. For those with reduced strength or a fresh injury, starting with the knee version is a safer option (Escamilla et al., 2016).
Takeaway: Begin with the side plank on your knees to reduce load and build stability safely.
3. Alternating Bird Dog vs. Prone Superman
The Bird Dog is one of my go-to exercises for patients in recovery because it activates both the core and back muscles while keeping the spine neutral. The Bird Dog exercise places around 2000 N of compressive load on the spine. In contrast, the Prone Superman, which involves lifting both arms and legs simultaneously while lying face-down, exerts over 4300 N, more than double the load (McGill & Karpowicz, 2009).
Takeaway: Opt for Bird Dog instead of Superman to prevent excessive load on your recovering spine.
4. Front Plank vs. Hollow Body Hold
The Front Plank is another excellent isometric exercise that strengthens the entire core without movement, minimizing spinal stress. It generates approximately 2400 N of compressive force, making it a safe option in early recovery. On the other hand, the Hollow Body Hold involves maintaining a curved position with both the upper and lower body off the ground, resulting in a higher spinal load of around 4000 N (Calatayud et al., 2019).
Takeaway: Front planks are better for minimizing spinal stress while still engaging core muscles effectively.
Conclusion: Start Slow, Build Safely
When starting out a core strengthening program, especially in the subacute stage or if you’re a beginner, selecting exercises that place minimal load on the spine is crucial to avoid re-aggravation. The McGill Crunch, Bird Dog, and Side Plank on knees are ideal core exercises to minimize spinal load, for building stability and strength while minimizing both compressive and shear forces on the spine.
These exercises provide a solid foundation for recovery, helping you regain strength safely without putting your back at risk. As you progress, you can gradually increase the difficulty and load, always keeping spinal safety in mind.
I hope you found this breakdown helpful!
Dr. Notley
Treating muscle and joint injuries in Winnipeg as an Athletic Therapist and Chiropractor since 2000.
Originally posted on May 17, 2022 @ 4:40 pm