A few years ago I was given the opportunity to train with Joe Sansalone at the Optimum Performance Training Institute in Columbia, MD. I learned much from him. One particular lesson he taught me was the way most people do their planks is incorrect. Planks can be a valuable exercise to improve the strength of our hips, endurance of the abdominals as well as a teaching exercise on to activate the abdominal muscles. In order to reap the gains of a plank, how you position yourself is key to what is getting stressed and where progress can be made.
The Saggy Shoulder
Interestingly, the muscles of the posterior shoulder, the deltoid and infraspinatus, increase their activity during weight bearing exercises like a plank. These muscles help to prevent a forward shoulder. A side plank is a weight bearing exercise that can be a strengthening vehicle for the shoulder muscles. It could be inserted into any general strength and conditioning program or any rehab program to develop enhanced shoulder motor control or strength.
When the shoulder is inactive during a plank, the stress from holding our body weight is forced into our soft tissues, such as the shoulder ligaments, labrum, joint capsule, and tendons. While these tissues are capable of tolerating this stress, they are not well-suited for it. Eventually, the stress will exceed these tissues' ability to tolerate it, which will lead to pain.
By pressing through the elbow and pulling the shoulders back, we are activating the muscles of the region. These muscles are much better suited to handle these stresses for prolonged periods. Additionally, your shoulder strength will quickly improve by making these small, yet highly valuable tweaks.
Inactive Hip
Often in the physical therapy setting, individuals with hip strength deficits are assigned clams or monster walks. These exercises target the muscles on the side of the hip, specifically the gluteus medius and minimus. While clams and monster walks are fine exercises for developing muscle and body awareness, they fall short when it comes to building functional strength sufficient to meet the demands of daily life or recreational activities. For example, when running, the lateral hip muscles experience 3.5 times the force of the body weight, and a clamshell exercise alone is insufficient to address this.
In studies that measure muscle workload, electromyography (EMG) is a common tool used to assess the level of muscle activation. The EMG measures electrical activity in the muscles, with higher activity indicating greater muscle workload. A clamshell exercise typically activates only 10 to 25% of the maximum muscle activation, whereas a side plank activates 76% of the maximum. To further intensify the exercise, a side plank with the top hip lifted can activate up to 103% of the maximum muscle activation. Although it is unclear how a measurement of 103% is possible, it is evident that the level of activation goes beyond the expected range.
I observe 2 faults at the hip during a side plank. The first is the hips are shifted back. The other is the hips are not lifted high enough. This will cause the stress of the activity to move into the hip flexor muscles or miss the hip all together. A standard side plank is one of the best exercises to strengthen the lateral hip musculature, the gluteus medius and minimus. To get the most out of this side plank for your hip, give yourself a quick check. You want the hips to be aligned between the shoulders and feet. Additionally, you should try to lift the downside hip away from the ground.
Poorly Positioned Pelvis
Stuart McGill, a foremost authority in exercise research on back pain, advocates use of the side plank. He notes it is unique in its ability to strengthen the muscles around the spine while minimizing the stress on the structures(ligaments, discs, joints) of the spine.
I notice 2 issues at the pelvis. The first is the pelvis is excessively tilted. The other the top side of the pelvis is excessively rotated behind the body. Both of these faults lead to displacing the forces of the plank. It creates an imbalance in working the posterior muscles of the back like the paraspinals and quadratus lumborum as well as the hip flexors. To ensure optimal trunk and hip loading, the pelvis should be tucked, abs and gluteals are engaged.
When performed well, the side plank benefits the whole body exercise. I like to start most clients with a simple standing plank against a wall. This lets me to teach them how to organize the shoulder, spine and hips as well as develop appropriate muscle activation. Once this is mastered, I will progress to a floor variation if appropriate. As I noted above, this exercise can be appropriate if you have shoulder, back, hip or knee pain. If you are in need of help, the first step is scheduling a visit.