STAY CENTERED: your guide to a healthy spine

Your spine is your body’s axis, the central line about which the rest of your body moves.  The bony structure of the spine is also the vault that protects your spinal cord and the nerves that run from the spinal cord to communicate with the rest of your body.  If you think of your brain as “command central” for all of your body’s movement and function, the spinal cord is a super highway delivering all that the brain has to offer to the rest of your body.

THE SPINAL COLUMN

The spinal (or vertebral) column consists of 24 vertebrae stacked one atop the other in such a way to allow for even distribution of weight in upright posture. 

There are four sections of the spinal column: cervical (7 vertebrae), thoracic (12 vertebrae), lumbar (5 vertebrae), and the sacrum & coccyx.

The vertebrae differ slightly in each section depending upon the importance of mobility vs. stability in that particular section of the spine.  Each segment of the spine is dependent upon the health and strength of the other spinal segments to function properly.

The spinal curves are important to maintain structural balance & prevent pain and injury.  On a side view of the spine there are four normal curves:  cervical, thoracic, lumbar & sacral.  Each of these curves is either anterior (lordotic) or posterior (kyphotic).  Abnormal spinal curvature is referred to as hyper (too much curve) or hypo (not enough curve) lordosis or kyphosis.

 When viewing the spine from the front or back (coronal plane), the spine should be straight.  Scoliosis refers to an S-shaped or C-shaped curve of the spine in the coronal plane.  Scoliosis often has a rotational component as well affecting the appearance of the rib cage and shoulder blades.

A huge network of muscles, ligaments (connecting bone to bone), and tendons (connecting muscle to bone) supports the bony structure of the spine. This network holds the shape of the spine:  maintaining stability and allowing movement in multiple planes.  In addition, between each spinal segment is an intervertebral disc.  The discs are fibrocartilaginous cushions that act as shock absorbers and provide a small amount of movement between the vertebrae.

The transverse and spinous processes are important muscle attachment locations on each vertebra.  The vertebral foramen is the space in which the spinal cord is housed.

The back muscles can be divided into deep, intermediate and superficial muscle groups.

DEEP BACK MUSCLES

MUSCLE	LOCATION	ACTION
Intertransverse	runs from transverse process to transverse process	sidebending
Interspinalis	runs from spinous process to spinous process	extension
Transversospinalis	Runs from transverse process to spinous process.  Includes: semispinalis (spanning 5-6 vertebrae), multifidus (spanning 3 vertebrae), and rotatores (spanning 1 vertebral level)	Extension, sidebending & rotation

The INTERMEDIATE BACK MUSCLES are collectively referred to as the erector spinae (also known as sacrospinalis).  This is really a bundle of muscles and tendons that runs vertically along the full length of the spine.

The SUPERFICIAL BACK MUSCLES include the rhomboids, trapezius, and lattisimus dorsi.  These muscles are more involved in movement of the scapula.  You can read more detail about the superficial back muscles in my post "Mobility + Stability ... Finding Your Rhythm"

The DEEP and INTERMEDIATE back muscles work together in relay fashion to maintain upright posture, proper spinal curvature and space between the vertebral bodies.  These muscles are largely automatic and should not require conscious effort to activate.  In fact, the deep back muscles should activate automatically in anticipation of all movement.  However, studies have linked weakness and insufficient activation of the deep back muscles to back pain.

With such a huge network of bones and connective tissue, it is no wonder that back pain is so prevalent.  4 out of 5 adults will experience back pain at least once in their lifetime.  The National Institutes of Health (NIH) reports that Americans spend $50 billion each year on back pain.  Back pain is a primary contributor to missed work days and disability.

There are multiple potential causes for back pain including: muscular strains and ligament sprains, herniated discs, spinal stenosis, osteoarthritis, osteoporosis, and fibromyalgia.  The good news is that most back pain can be treated without surgical intervention.  In fact, the National Institutes of Health considers exercise the most effective way to speed up recovery from low back pain.  Exercise programs to heal and prevent back pain should focus on proper spinal alignment.

The most common postural / alignment changes associated with low back pain are loss of lumbar lordosis (“flattening” of the low back) and increase in thoracic kyphosis (“hunchback”).  Miyakoshi et.al. (2011) studied 630 Japanese men & women 50 -94 years old and evaluated the relationship between spinal alignment, mobility and chronic low back pain.  They found that people who had low back pain severe enough to affect their ability to walk had decreased lumber lordosis, increased thoracic kyphosis, as well as decreased range of motion and mobility in the thoracic and lumbar spine in both extension and flexion movements.  Abnormal posture was also associated with a decline in walking ability. 

Weakness and fatigability of the deep back muscles has been cited as a primary reason for low back pain.  Additionally, weakness of spinal extensor muscles is thought to be a primary cause for walking disturbances in people with increased lumbar kyphosis (“flattening” of the low back). (Arokoski, et.al (1999), Kamkaanpaa, et.al (1999), Mannion, et.al. (1999), Miyakoshi, et.al. (2011), Taimela, et.al. (1999)).

Exercise programs to support back health should educate students about proper spinal alignment and teach them to stretch and strengthen the muscles of the spine to allow for movement in flexion, extension, lateral bending and rotation. I will admit I have an obvious bias in promoting The Dailey Method as the best exercise program for back health, but my bias comes with good reason.  The Dailey Method provides in-depth education in a fun group format and teaches students how to access the deep stabilizing muscles of the spine in a way that allows them to carry that deep body knowledge with them into a large range of exercises including focused neutral spine work, extension, flexion, lateral bending and rotation. 

For a great neutral spine exercise, check out my earlier post “Your Abdominals from the Inside Out”.  This post shows an exercise called “dead bug”.  Dead bug is great for training not only the deep abdominal muscles, but also the deep spinal muscles that support the natural curves of the spine.

In this article from the ChicagoTribune Jill Dailey describes Spinal Extension exercises and Neutral Spine Plank; two fantastic Dailey Method exercises for strengthening the deep back muscles.

Exercises performed with the lumbar spine in flexion target the outer layer of abdominals.  There has been controversy about lumbar flexion exercises in the literature for a number of years.  This is due mainly to the lumping of all spinal flexion exercises into the category of large range of motion flexion exercises without the support of the deeper layers of abdominal muscles.  Here’s a link to a very comprehensive review of the literature outlining where the controversy with lumbar flexion began and highlighting how inconsistent the literature really is on the subject.  That said, if you are a fitness professional, it is surely essential to know your students and their bodies.  If you or your students have a history of back pain or find any particular spinal motion uncomfortable, your exercise program should be modified to accommodate. 

One more link … here are four great yoga poses to incorporate into your fitness regimen to improve your back flexibility and health.

Your spinal health is essential to your overall well being and comfort in your daily life.  Take the time to learn about the muscles that support your spine and you will reap the benefits of longer more comfortable life.  Not only will optimal spinal strength and flexibility keep you pain free -- it will keep you looking and feeling younger too!

References:

http://www.ninds.nih.gov/disorders/backpain/detail_backpain.htm

Arokoski,  J.P., Kankaanpää, M., Valta, T., Juvonen, I., Partanen, J., Taimela, S., et al. (1999). Back and hip extensor muscle function during therapeutic exercises. Archives of Physical Medicine and Rehabilitation, 80: 842‐850.

Contreras, B. & Schoenfeld, B. (2011). To Crunch or not to crunch: an evidence-based examination of spinal flexion exercises, their potential risks, and their applicability to program design. Strength & Conditioning Journal. 33:4: 8 -18.

Kankaanpää, M., Taimela, S., Airaksinen, O., Hänninen, O. (1999) The efficacy of active rehabilitation in chronic low back pain. Effect on pain intensity, self‐experienced disability and lumbar fatigability. Spine. 24: 1034‐1042.

Mannion, A.F., Muntener, M., Taimela, S., Dvorak, J. (1999) Volvo 1999 award: A randomized clinical trial of three active therapies for chronic low back pain. Spine. 24: 2435‐2448.

Miyakoshi, et.al (2011) Prevalence, spinal alignment, and mobility of lumbar spinal stenosis with or without chronic low back pain:  a community-dwelling study.  Pain Research and Treatment, 2011, 1-5.

Taimela, S., Kankaanpää, M., Luoto, S. (1999) The effect of lumbar fatigue on the ability to sense a change in lumbar position. A controlled study. Spine. 24: 1322‐1327.