All movement is thought to originate through the rotation of the spine and the muscles that segment to the pelvis. You can think of the ribcage, spine and pelvis as a column that twists to create forces which transmit to the extremities or limbs. The limbs are just an extension of this motion. The arms, legs and neck simply serve to amplify the movement. The fact that quadruple amputees can still walk on the bottom bones of their pelvis makes this point very clear.
The body uses three systems to stabilize this bony column to provide a base for movement. The first, is the actual structure of the Thoraco-Lumbo-Pelvic System (e.g., pelvis, spine, and ribs). The second, is the neural control system that constantly senses movement then dictates how and when the muscles should contract or release. And finally, the actual muscular systems which are comprised of two subsystems; the inner unit or intrinsic stabilizers which attach directly to the spine and pelvis, and the superficial or outer unit muscles that create active stabilization.
Muscular Sling Systems
Every pattern of movement in the body is facilitated through the coordinated contraction of a grouping of muscles. When one muscle contracts the force spreads through the body like a wave. These muscles, which either absorb or create forces in the body, can be grouped into segments that are commonly referred to as slings or movement trains.
The inner unit’s main role in this is to stabilize the pelvis, spine and ribcage while the outer unit, made up of the slings, move the body by absorbing or transmitting forces. While there are many of these sling systems, they are generally grouped into four categories depending on their location. These include: the Anterior Oblique, Posterior Oblique, Lateral, and Deep Longitudinal Sling Systems. They often overlap depending on the change in forces applied on the body. Gravity, momentum and ground reaction forces are just a few examples of what can impact the recruitment of the slings. The big takeaway here is that they work together to optimally line up the joints and transfer load efficiently through the column.
When the grouping of muscles that make up the slings contract in the right sequence, they help us to move better, produce more force and stabilize the body. However, if there is an imbalance in the force transmission due to altered tension relationships in the muscles (e.g., some are too tight, others too lack) this can create malalignment of the joints and contribute to loss of stability. So, if there is a weak link or hole in the system this can lead to dysfunctional movement and injury cycles.
So How Do the Holes in the Systems Pop Up?
Both movement and gravity create mechanical loading on the joints and connective tissues. Commonly, redundant activity related disorders can create excessive wear and tear on one of the structures of the body. Compensatory reactions begin where the body recruits or favors one or a grouping of muscles over another in an attempt to control the maladaptive movement distortions. These muscles not only shorten and become tight, but they also exert a restrictive or inhibitory influence on the muscles which they oppose. Recall that all muscles have an antagonistic relationship. One must flex while the other must lengthen. When this natural process of lengthening and contracting is disrupted it’s referred to as altered reciprocal inhibition.
So basically, if you move the wrong way consistently your body will begin to favor certain muscles over others which will create holes in the muscle firing patterns of the sling systems. This creates a feed forward system of dysfunction into other areas of the body. That’s why something as benign as a bruised heel bone can contribute to shoulder dysfunction.
Sciatica Pain and Asymmetrical Weight Shift
Asymmetric weight distribution in our posture and in our daily activities can lead to recruitment strategies that impact the sciatic nerve and lead to an issue called piriformis syndrome. The habitual process of shifting one’s weight over to one leg alters the way the body transmits forces through the pelvis. This predisposes the lateral rotators of the thigh bone to overwork as they try to stabilize the hip and leg. The piriformis is one of the lateral rotators. It attaches the sacrum to the femur. This can cause the piriformis to become tight or spasm. As the sciatic nerve runs very closely to the piriformis, if the muscle becomes tight it can become compressed and cause pain which can radiate down the leg.
How Does This Happen?
There are several common patterns of compensation that occur because we typically move in similar patterns in our daily activities. Keep in mind that the greater majority of us are right-handed. Every day, we open the car door and tie our shoes in the same way. This predisposes us to a muscular recruitment strategy that reinforces the strength relationships in specific areas. This makes one side of our bodies dominant. If we don’t interfere with these strategies using corrective exercise as a counter conditioning, it practically ensures injury cycles.
Yes, There is a Solution!
- Recognize which muscles are responsible for proper femoral stability and strengthen them (like the adductor complex, gluteus medius and gluteus minimus).
- Increase the mobility of the muscles that contribute to sciatica pain (such as the piriformis).
- Condition your nervous system with functional movement patterns that coordinate the appropriate muscular firing patterns, including the lumbo-pelvic hip stabilizers. (You’ll get an example in the video below so read on!)
- Reduce movements that require lumbo-pelvic hip control until adequate strength balances can be obtained (i.e., lateral or transverse movements).
- Be mindful of your posture and daily activities – sitting for long periods of time with crossed legs or standing with your weight shifted to one side of the body. Try not to sit for longer than 20 minutes at a time and keep your center of mass over your midline.
How to Assess?
Want to find out if you have an asymmetrical weight shift? Here is a quick movement assessment you can complete to determine if you exhibit the signs. Stand with your hands on your hips with your feet pointed straight ahead. Lift one leg up by bending at the knee drawing the foot behind you. Squat down to a comfortable position then come back to your beginning position. Repeat several times then switch legs and repeat.
- Did the opposite side of the working leg hip drop?
- Did your torso rotate inward?
- Did your knee drop or rotate inwards?
If you answered yes to any of these questions, you tested positive for this common posture problem and you’ll want to pay attention to what comes next and watch the accompanying video on how to correct it.
Simple Corrective Methods
Correcting Overactive Muscles
Because we move in patterns, our bodies favor the use of certain muscle groups over others. Since we all have a tendency towards overusing one side of the body, this can place the piriformis muscles into an overactive position. You’ll want to lengthen them via self-myofascial release, and then follow the myofascial release with neuromuscular stretching.
Below are the muscles you’ll want to focus on for asymmetrical weight shift this week:
- Piriformis Self-applied pressure using a pincer grip for 30-60 seconds each
- Stretch or lengthen each for 30-60 seconds each
Correcting Underactive Muscles
As mentioned above, pain in the body is commonly caused when how we move forces certain muscles to work overtime, while other muscles become lazy and don’t want to function. You’ll need to wake up these lazy muscles through isolated strength movements.
The adductor complex, gluteus medius and gluteus minimus are the muscles you’ll want to isolate this week:
- Adductors, Gluteus Medius & Minimus | Side lying adductor roll
- Lumbo-pelvic hip stabilizers | Single leg balance
- Lateral Sling Integration | Lateral Lunge – 2 sets on each muscle group 10-15 reps using a slow opening of the muscle, isolated hold at the bottom of the movement, followed by a controlled shortening of the muscle.
Now that you know which muscles are typically underactive and overactive, let’s put it all together for you. Watch the video for a step-by-step breakdown on how to target each of these areas. Before you get started, make sure you have a lacrosse ball handy.
Start off by applying the techniques three times a week and build from there. Every so often, reassess your posture and see how far you’ve progressed. Soon, you’ll start to see noticeable changes in your body position and mobility!