February 2021
Perfect Posture? No Such Thing!
Posture and body mechanics matter a great deal to how we feel and function, though contrary to popular belief, there is no one perfect posture or way of performing a task. We all have different body types, physical histories, levels of strength and mobility. There are, however, better and worse ways to sit and move throughout the day; learning how and why can help you to improve how you feel before, during, and after activity.
The Biomechanics of Our Body – How We Were Built to Hold Our Heads Up, Absorb Forces, and Move!
Spinal Alignment: Whether we are in motion or still, the position of our spine has an effect on our passive structures (ligaments, joint capsules), our active structures (muscles), and our neural structures (nerves). There are four natural curves in the spinal column: cervical (neck), thoracic (upper and mid-back), lumbar (low back), and sacral (pelvis and tailbone). These curves, along with our intervertebral discs, help absorb and distribute stresses that can occur with everyday activities such as walking. The curves are important for balance and helping to keep our bodies upright. They also help support the weight of our head, which weighs between 10-15 pounds, 11 pounds on average. (Our brain only weighs 3.5 pounds!)
Postural Muscles: As discussed in Brain Body Synergy’s previous blog on core stability, (https://www.brainbodysynergy.com/post/core-so-much-more-than-you-may-think), our core muscles are responsible for maintaining spinal positioning and stability. The postural muscles that help hold up our spine and head are not just in the abdominal region, but all along the spine from our skull to our tailbone. There are at least 20 muscles throughout the head and neck region that control the position and movement of our head. While most of our muscles require conscious thought to contract and are not always on, gravity is working 24/7 to pull us downward. To have active posture is to periodically think about contracting these muscles to help support your spine and change position.
Spinal Discs: The intervertebral discs that sit between the bones in our spine act as shock absorbers. Not only the position but also the movement of the spine affect the amount of load on our discs. As discussed below, moving the head or trunk forward, away from a neutral position, increases the pressure on the discs. Additionally, evidence has shown that spinal loading is essential to maintain the health and function of discs. Dynamic loading of a certain magnitude, frequency and duration, has been shown to maintain the matrix balance within the disc, as well as assist in the differentiation of stem cells. On the other hand, prolonged static loading causes cell death and increases disc degeneration. In a real life example, this means that moving periodically and shifting your weight when sitting for a prolonged period of time is preferable to not moving the body much at all.
Nerves: Our nerves run throughout our entire body, exiting the spinal cord from all levels of the spine, often traversing through narrow joint spaces and tight muscles. The curves of our spine, the make-up of our muscles, and the position of our body can all affect how our nerves are able to move (yes, nerves move), and function. By being conscious of how your head, spine and limbs are positioned and how they move, you can improve the health and efficacy of your nerves.
Blood Flow: Blood circulation is the key to life in our bodies. It distributes oxygen and nutrients, and removes waste, among many other amazing properties. Muscle contractions increase blood flow to the muscles, and inactivity decreases blood flow to areas that don’t move. In addition to the effects of muscle contractions, blood flow can be affected, like nerves, by your position or movement patterns if they are being stretched or compressed. Moving frequently and consciously improves blood flow throughout your brain and body.
Why Do Active Posture and Body Mechanics Awareness Matter?
The position of our head has a significant effect on the forces on our spine as well as how our postural muscles work. When our head is positioned in a neutral position, meaning sitting atop of the cervical spine and not excessively forward, the weight of the head is roughly 12 pounds. As the head and neck move in a forward direction away from neutral, the relative weight of the head increases, which places more stress on the intervertebral discs, increases muscular demand, and can put stress on ligaments. For short periods of time, this may not be significant; however, over a longer period of time it can have negative effects.
With respect to the lumbar spine, or low back region, postural changes have varying effects on disc pressure in different positions. Disc pressure is the lowest when lying supine (flat on your back), and increases in the standing and seated positions. The more we lean forward, the more pressure there is on discs; in fact, sitting and leaning forward while holding an object increases the load on the discs even more than when doing so in standing.
Beyond the Spine: The spine is not the only part of our body we should keep in mind when it comes to positioning and movement. The way our shoulder blades (scapulae) sit and move affects how our shoulder joints function, and the way we move and stabilize (or don’t) our hips/pelvis and where our feet are affect how our knee joints function. They also affect how our muscles and nerves work, and malpositioning can lead to muscle weakness, radicular symptoms (tingling or numbness in the arms/hands or legs/feet), and sometimes even pain. Whether you are sitting or standing and moving, being aware of your body as a whole can improve how you feel and perform.
How Can We Think About Posture and Movement Differently? Start Thinking About It!
Much of our adolescent and early adult lives are spent learning how to master tasks efficiently so that we can do many different things without spending extra energy thinking about or performing these tasks. We were designed to be energy efficient. One of our most extraordinary skills is the ability to learn how to do something and continue to do it without thinking about it, in order to allow us to be able to do multiple things at once, in increasingly complex environments. Once we have mastered a task, whether it be sitting, walking, or even exercising, we tend not to think about how we do it, because our brains and bodies, being ever-energy efficient, are stingy with the amount of resources they want to spend on what they consider to be unnecessary efforts that are already learned.
When we learn a new skill, such as a method of chopping vegetables, or a sport, or a martial arts form, it requires a great deal of conscious thought and effort, as the brain tries to learn and master these skills. We use nearly constant feedback from the body to figure out if we are performing the task well and frequently fine tune what we are doing. On the other hand, when we sit for a prolonged period of time, or perform physical tasks, such as household chores, that we have done 1000 times before, lack of conscious thought about our bodies can lead to imbalances that occur slowly, over a period of time, which can contribute to tightness, weakness, or pain. Prolonged immobility can also lead to decreased blood flow and nerve function, and moving with suboptimal body mechanics can lead to strains or overuse injuries.
Proprioception – Self-Awareness: More than trying to find a “perfect posture” or “perfect body mechanics” it’s about being aware – aware of how your body is positioned, and aware of how your body feels in that position, a concept known as proprioception. We know where we are in space in large part from our proprioceptors, sensory receptors that lie in our skin, muscles, tendons, and joints throughout the body. These nerves fire in response to all different types of stimulation, including light touch, vibration, mechanical strain, joint position, and movement, or lack thereof, to name only some. It is through these receptors that you know where your arm or leg is in space, or how quickly your limb is moving.
When the brain and body get used to a certain position or movement pattern, the muscle memory is further engrained, and the amount of thought or awareness decreases, so you can focus on other things. If you sit in a slumped position for a long period of time with your head and shoulders forward and your low back rounded, over time, muscles tighten and weaken, nerves can get impinged, and blood flow decreases. If you’re doing a repetitive activity such as vacuuming that can involve bending and reaching, certain motor patterns that may not be beneficial to your body can get reinforced. Through increased focus on your muscular and neural feedback and output, you can decrease or avoid becoming habituated to positions and movements that don’t serve you well, and improve your muscular control and endurance.
Where to Start?: The first step is leaning what positions and movement patterns work best for you. Working with a physical therapist can allow you to learn your strengths and areas for improvement, as well as how to properly engage muscle groups and improve neuromuscular control. After the initial process of learning what things you should be working on, the sky is the limit for your progress, and all you need is your brain to get it kick-started!
Tips / Examples:
Driving:
· Try to be aware of your position and engage your postural muscles from your head down to your pelvis.
· At times of increased stress, or without giving our bodies much thought, we often end up with our head forward toward the windshield and our shoulders elevated up to our ears. Try performing a chin tuck back into the headrest as well as a slight shoulder blade squeeze back and down, to improve your spinal alignment and relax those tight upper traps.
· Try not to let the low back arch.
· Try to move your legs as much as able and keep the feet/knees in a position that does not cause knee discomfort or pulling on the hamstrings/sciatic nerve/low back.
Computer use:
· Try to get up at least every 30 minutes.
· To counter the ever-present effects of gravity, engage your core and postural muscles to keep your head and spine in neutral positions, meaning not excessively forward or backward.
· You can do some backward shoulder rolls to improve blood flow and mobility of the muscles in your neck and upper back.
Cardiovascular exercise:
· Try to keep your trunk upright and your head in a neutral position versus forward.
· Keep your lower abdominals engaged as much as able. The more you actively use your brain to be self-aware, the more your body will cue you to move properly.
On www.brainbodysynergy.com you will find a section called Body Mechanics Education under the Educational Resources tab. This section includes some general guidelines for improving how we perform some common daily activities, such as sleeping, bending down, and lifting. For individualized recommendations, book an appointment with me now to get started on your path toward Brain Body Synergy!
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