Posture Evaluations, Part 7: Thoracic Spine Analysis
By Jeffrey Tucker, DC, DACRB
Patients often ask me, "What causes bad posture?" I often hear myself answering with something like, "How many hours do you spend at work each day?" The patient responds with, "On average, about eight to 10 hours," to which I say: "During your work time, you probably sit unconsciously in a slumped posture and in improper body positions. Some people just engage in repetitive movements. Either way, this can create muscle imbalances leading to poor posture." For those patients who really "get it," I might add, "I think that the mind and body communicate and that psychological distress from work, family, finances (or whatever else I have heard them share with me) shows up in our posture."
Would you agree that poor self-esteem and depressive symptoms are displayed in our posture? Another cause of poor posture is a lack of a variety of movement in our activities of daily living and overall poor flexibility. In essential ways, our unique cultural, mechanical and spiritual histories are part of what affects overall posture and health.
Last year, I was given the opportunity to teach a thoracic spine rehab course. I had never been to a "thoracic spine seminar," let alone put together eight hours of teaching material on the subject. The seminar could have been called, "The Thoracic Spine – The Forgotten Area Between the Lumbar Region and the Cervical Region." I continue to learn the compelling interconnection between the thoracic spine and the cervical and lumbar regions.
The Thoracic Spine
The thoracic spine consists of three sections. T1 and T2 are examined with the cervical spine because the nerve roots serve the upper limbs; T3-T6 is an area that often gets spinal fixations and is the site of the "T4-5 Syndrome." This is characterized by upper thoracic stiffness, non-dermatomal upper extremity (arm and hand) paresthesias or numbness; it may have associated headache and responds to thoracic spinal manipulation. T6-T12 is intimately related to the thoracolumbar fascia and articular displacements are frequent here.
While it is true that thoracic spine mobility is restricted by the rib cage (one of the reasons why <1 percent of disc herniations occur in the thoracic spine is because the rib cage does a good job of limiting spinal flexion), it is far from immobile. The movement most likely to hurt with a disc lesion is the extreme of passive rotation.
The Upper Thoracic Spine
The zygapophyseal joints of the upper thoracic spine are orientated toward the frontal plane. This limits spinal flexion to about 4 degrees per segment from T1-T6, but it allows about 8 degrees of rotation per segment from T1-T8. From T1-T10, you've got roughly 6 degrees of lateral flexion per segment.
The Lower Thoracic Spine
Because the zygapophyseal joints change orientation to a more sagittal plane alignment in the lower thoracic spine, the ability to flex increases from about 4 degrees to about 12 degrees per segment as you work your way down from T6-7 to T12-L1. The orientation of the joints also limits rotation to about 2 degrees per segment below T10.
You can see that the thoracic spine does move quite a bit. In fact, a loss of mobility in the thoracic spine can lead to neck, shoulder, lower back, and even lower extremity dysfunction and pathology. These are reasons we must spend time doing fascial therapy, joint mobilization/manipulation and teaching thoracic spine self-mobility drills.
Thoracic Spine Evaluation
James Cyriax wrote in his book Illustrated Manual of Orthopaedic Medicine (page 169), "Neck flexion stretches the dura mater at both cervical & thoracic levels. Pain on neck flexion is therefore common to a defect at either level, but if the other neck movements are full and painless, attention is diverted to the thoracic spine." Pretty simple stuff for those of us into movement analysis!
Visual postural analysis: A line from the mid-thoracic region to the sacrum should be slightly posterior to the back of the head (1-2 cm). In normal posture, T5 forms the apex of the thoracic kyphosis or the end of the lumbar lordosis. If you see a flat, multi-segmental region between T2-T6, consider dural protection, overactive or short rhomboids, or serratus posterior superior or stiff cervicothoracic segments, which are compensated for by increased thoracic extension.
Testing contractile structures: After the visual analysis, testing the contractile structures in and around the thoracic spine can offer many clues:
Muscular lesions do not radiate pain from the posterior thorax to the anterior (or vice versa); such distribution is sufficient on its own to acquit the muscles.
Increased kyphosis: There are predictable biomechanical effects of thoracic kyphosis (slouched posture). In sitting, the cervical spine and head move forward. This causes excessive upper cervical extension and lower cervical anterior shearing, often creating neck pain and headaches. If treatment is only directed to the cervical spine and not at the thoracic stiffness causing the problem, symptoms may temporarily reduce, but the pain will never go away.
Prolonged slumped sitting and thoracic hyper-kyphosis cause posterior pelvic tilting, which contributes to lumbar flexion or loss of lordosis. The prolonged positioning of the spine in thoracic kyphosis and lumbar flexion can contribute to permanent elongation of ligamentous and muscular tissue.
Around the shoulder, we see decreased abduction and isometric strength in the deltoid and supraspinatus muscles; scapular protraction; decreased upward rotation and posterior scapular tilt (the scapula is fixed in anterior tilt and downward rotation); and slightly increased scapular internal rotation / lack of scapular external rotation.
Thoracic Spine Corrections
Manipulation: Don't forget to manipulate the thoracic spine with neck pain complaints. In a study by Joshua A. Cleland, et al., patients with mechanical neck pain who received thoracic spine manipulation and exercise exhibited significantly greater improvements in disability at both the short- and long-term follow-up periods and in pain at the one-week follow-up compared with patients who received exercise only.
Soft-tissue therapy: Thirty years ago when I was in chiropractic college at LACC, my head clinician was Dr. Richard Andrus. He was a certified Nimmo instructor, taught by Dr. Raymond Nimmo himself. Dr. Andrus taught his interns the importance of muscle and fascial therapy. Now others are talking about fascial therapy like it's new, and it certainly is one of the hottest topics in manual therapy! When did fascial therapy ever go out? Now we have workshops from Stecco, Tom Myers (Anatomy Trains), ART, Barnes and a host of others. I don't know if Ida Rolf is smiling on us or rolling over in her grave!
My point is the thoracic spine needs fascial therapy and mobility training. The indications for fascial therapy are decreased mobility in shifting one layer versus another. Don't make it too complicated: Find the resistant direction of fascial shifting, take out slack until resistance is felt, ask the patient to breathe in and hold their breath, wait at the barrier until release is "sensed," take out slack to the new barrier during exhalation phase. My favorite tools for fascial therapy are still my hands, deep muscle stimulation and stainless-steel, hand-held "scrapers."
In the next article, I will share some of the specific corrective exercises I do for a hypomobile thoracic region and hyperkyphosis.
Editor's note: This series on posture evaluations began last year (May 2010 issue). Parts 2, 3 and 4 ran in the July, September and November 2010 issues, respectively; parts 5-6 ran in the January and March 2011 issues.
Click here for more information about Jeffrey Tucker, DC, DACRB.