About 80% of us will suffer from orthopedic injuries, either acute, chronic or both, at the low back or shoulder at some point during our time as exercisers (Vallfors, 1985). The area inferior to the shoulder complex and superior to the lumbar spine, known as the thoracic spine, plays an enormous role in the functionality of the shoulder and low back. A thoracic dysfunction almost certainly means weakness and instability at the shoulder and low back, and quite often leads to injuries in those areas. In this article we will be discussing the thoracic spine, which although far less common of a topic than the low back and shoulder is no less important – in fact, one could argue perhaps even more so.
In this article, the fitness professional will learn how to:
- Describe the basic anatomy and function of the thoracic spine.
- Identify common problems associated with thoracic spine dysfunction.
- Implement methods to improve thoracic spine mechanics.
Basic Anatomy of the Thoracic Spine
A comprehensive discussion of the anatomical structures of the axial skeleton is far too extensive to cover in this section, but the basic structure of the thoracic spine is important for the fitness professional to understand.
The thoracic spine along with the sternum and rib cage make up the thorax. This region provides a stable base for the craniocervical region, protection for organs and mechanical bellows for breathing. The thoracic spine has 24 apophyseal joints, 12 on each side, which provide the primary mechanism for thoracic mobility (Neumann, 2002). They are well stabilized by the ribs, and protect the spine from trauma. For example, during a fall or collision, the impact is absorbed and dissipated by the ribs, associated muscles and connective tissues, therefore sparing the spinal cord damage in all but the most severe accidents (Neumann, 2002).
Although the range of motion at each thoracic intervertebral disc is relatively small, the cumulative motion over the entire thoracic spine is considerable. The degree of mobility increases toward the cervical region and decreases toward the lumbar region (Neumann, 2002). This is an important distinction for the fitness professional to note, as it will be a factor in the programming that will be discussed later in this article.
Maintaining thoracic normalcy requires a delicate balance of intrinsic forces (muscles, tendons, ligaments and their neuromuscular control) and extrinsic forces governed by gravity. When the balance becomes dysfunctional for any reason, deformity and postural distortions occur. Although injuries to the thoracic vertebrae such as herniated discs and nerve impingements are relatively rare -likely due to the stability provided by the rib cage - the effects can and will be transferred to other areas. As with most joint dysfunction, the areas above and just below (i.e., scapula, cervical vertebrae, gleno-humeral joints and lumbar spine in this case) the affected area receive the tissue overload and typically show the symptoms even though they may not be the cause (Neumann, 2002).
Range of Motion and the Effect of 1 Degree
As mentioned, the approximate ranges of motion for the thoracic spine in totality exceed that of the lumbar spine. Thoracic range of motion decreases toward the proximal end of the thoracic column, where it tends to become more lumbar in nature. Normal ranges of motion are as follows (Neumann, 2002):
Sagittal Plane: 30-40° flexion, 20-25° extension
Frontal Plane: 25°
Transverse Plane: 30°
It is critical for the fitness professional to note that sagittal plane flexion is greater than extension - a slight kyphotic posture is normal. However, this normal curve that’s slightly convex to posterior makes it vulnerable because kyphosis leads to problems at the shoulder and lower back. There is already a slight kyphotic posture in a normal thoracic spine, therefore the difference between “normal” and problematic are very subtle. Because of an already slightly kyphotic nature, any force that would encourage further kyphosis (e.g., lifestyle, improper training, body type, etc.) can turn normality to dysfunction very easily and quickly. The difference between thoracic health and dysfunction may be as little as one degree of flexion (Sahrmann, 2002).
The Contributing Factors
Prevention of further flexion is crucial to optimal length-tension relationships among musculature originating and inserting on or near the thoracic spine. The key muscle complexes are the erector spinae (spinalis, longissimus, Iliocostalis), multifidi, rotatores, interspinalis, and transversospinalis. All act as thoracic extensors as well as spinal stabilizers. As we’ll discuss further in this article, this creates a programming challenge for the fitness professional.
Lifestyle, body type, and improper training can lead to increased kyphosis (Sahrmann, 2002). Postural stress, pattern overload, repetitive movement, lack of core stability, lack of neuromuscular efficiency all need to be considered when designing programs for clients, but especially those who may be prone to kyphosis (Clark, 2001).
Common Problems Associated with Thoracic Spine Dysfunction
Although many problems can occur with excessive kyphosis - Scheuermann disease and osteoporosis, among other issues - we’ll limit the discussion to movement and exercise-related issues (Neumann, 2002).
Excessive kyphosis may lead to:
1. Compensatory cervical spinal extension
Since kyphosis will result in a forward tilt, the excessively kyphotic individual needs to extend the cervical spine in order to maintain level eye placement to walk, drive and perform other daily functions. With even excessive kyphosis, a person can extend his or her upper craniocervical region enough to maintain a horizontal visual gaze. This strain can lead to headaches and reduced balance motor control due to the now altered equilibrium (Neumann, 2002).
Additionally, the cervical extension will result in a shortening of the cervical extensors (e.g., the interspinalis, semispinalis capiti, and levator scapulae) as well as muscle tissue in the upper shoulders, such as the upper trapezius. Adhesions, trigger points, altered neuro-muscular control, and further movement dysfunctions and postural distortions may occur as a result.
2. Compensatory lumbar mobility
In addition to creating compensation above the thoracic spine, kyphosis can and will create compensations below - at the lumbar spine.
The spine’s natural reaction to thoracic kyphosis is to extend the cervical spine as described above, but also to extend the lumbar spine in order to maintain an upright torso during walking, running, exercise, etc. The resultant lumbar extension may lead to higher than normal compressive forces on discs, higher risk of herniation and decreased spinal stabilization during day-to-day and exercise related activities. This can decrease the desired training effect even if the client is fortunate enough to avoid an acute or chronic injury pattern.
Dependent upon the individual and the variables specific to his or her situation, the reverse may happen as well. Body type, improper exercise technique, poor motor control, etc., may also present lumbar flexion in addition to the thoracic kyphosis. A client may have a slight spinal postural distortion statically, but dynamically will demonstrate lumbar flexion and a posterior pelvic tilt. This position may not only present the possibility of the issues delineated above, but may double the risk by causing excessive mobility throughout the lumbar area in both sagittal plane directions, flexion and extension.
3. Shoulder dysfunction
Greater than normal ranges of thoracic flexion often lead to an anterior glide of the humeral head in the glenoid fossa. Shoulder - and specifically gleno-humeral function - are dependent upon minimal non-rotational movement and compensation in the glenoid fossa. Anterior or posterior gliding, and/or elevation and/or depression of the humeral head within the fossa, can and will lead to shoulder trauma. On a local level, tissues, ligaments and tendons of the pectoralis major, minor, latissimus dorsi, deltoids, and rotator cuff may suffer damage as a result (1). Simply stated, if the ball in the socket does anything but spin, there can be shoulder issues. Since thoracic flexion leads to movements other than rotation, then we as fitness professionals need to avoid (and then address) thoracic flexion with our clientele if we want to avoid shoulder injury and pain.
Additionally, excessive thoracic flexion leads to an anteriorly tilted scapula which limits shoulder flexion. In addition to the possible trauma mentioned above, this also limits the amount of strength in the shoulder and decreases the desired training effect. Simply decreasing the amount of thoracic kyphosis has been shown to improve shoulder flexion (Sahrmann, 2002) and improved shoulder flexion means improved workouts for your clients.
Methods to Improve Thoracic Spine Mechanics
At this point it’s probably obvious to the fitness professional that thoracic flexion beyond the degree that is considered normal needs to be assiduously avoided. Some aspects of thoracic function may be beyond our control, such as body type, but for the most part function can be improved (possibly permanently) in order to prevent potential problems and/or aggravation.
The most basic and important point to remember when programming for your client, and therefore what needs to be explained to them (and repeated, if necessary) is the following:
You cannot fix a problem unless the cause is removed.
You can put a bucket under a leaky ceiling to temporarily relieve yourself of damage, but you’ll be doing it forever if you don’t fix the ceiling. Ditto in this scenario.
If there is postural stress from lifestyle factors such as jobs, commutes, carrying bags or children, you can remind your client to be aware of the stress they are causing. Remind them to maintain proper posture when carrying heavy items. Remind them to sit tall when sitting, or to take a mobility break with some assigned homework drills from their trainer a few times during the course of day.
Admittedly, we have less control over postural stress issues caused by body type. Generally, people who have large weight distributions on the anterior aspect of their upper body will be more likely to exhibit excessive spinal flexion. This is difficult for the fitness professional to address because even though you may be discussing the client’s kyphosis, what they are likely to hear is criticism of their body type.
There are two ways a fitness professional can address this, albeit in a somewhat passive aggressive manner:
First is to focus on their nutrition and eating habits. Body fat and overall weight loss is something that may help flexion issues and can be addressed during their time with you.
Secondly, you can also stress the importance of getting proper rest both during the day and when sleeping at night. Fatigue is a rather large factor in spinal flexion. The minute we begin to feel tired, the slouching posture tends to begin. Taking breaks when possible and staying rested during the day, as well as prioritizing a good night’s sleep will lessen the degree of fatigue-induced spinal flexion.
A less subtle job, and more under the control of the fitness professional, is to remove any situations where there may be pattern overload in the client’s exercise regimen. This should be simple during the aspects of their workouts governed by your programming. Be sure there are equal parts or necessary applications of pulling and pushing, lower body and upper body, stabilization and dynamic movements, varying planes of motion, etc.
However, if they are training outside their time with you, explain what they’ll need to watch for. Unfortunately, your client can exacerbate the situation that they’re trying to avoid. Remember, you can’t fix something until the cause is removed.
Your program for your kyphotic client should be heavy in core stabilization training. One of the more overlooked causes of thoracic and spinal immobility is a lack of neuromuscular control over the “inner unit” or spinal stabilization mechanisms. There is altered neuromuscular efficiency in individuals with poor posture, and alterations in strength and stabilization occur secondary to altered postural control (Clark, 2001). When motor control is less than optimal in these crucial, yet mostly involuntarily firing, muscle systems the body responds by calling in larger prime movers as synergists. As an example, your client may get to a depth when squatting where balance and stabilization may be an issue. If the spinal stabilizers don’t fire and large prime movers are called in as synergists, this may lock up the joints that they should be controlling and should be mobile – like the shoulders, hips and thoracic spine. Over time, this lack of efficiency leads to restrictions on and around the prime movers of thoracic spine, creating even further dysfunctions. Proprioceptively enriched and challenging coordination exercises that promote effective core stabilization will go a long way when attempting to improve thoracic function. As mentioned earlier, the fact that many of these muscle groups are responsible for movement and stabilization makes this a tricky issue.
My suggestion is to overload the client with unilateral and split-stance exercises because both have a tendency to create more of a demand on stabilizing the spine and preventing unnecessary extension and/or rotation. Although many types of equipment can be used, items such as tubing, sand bags and kettlebells (which provide differing degrees of variable resistance) are great tools for neuro-muscular control and stabilization training. Presses and rows (vertical and horizontal), as well as split-stance squats, chops and lifts provide many options that can be progressed and regressed depending on the individual and his or her program.
Drills that specifically attack the muscles and tissues of the thorax:
- The "Bretzel": This exercise, designed by Gray Cook and Brett Jones, is an advanced move for clientele who have the mobility to get into this spineposition. Those lacking the proper hip and shoulder mobility should regress to the rib grab or side-lying reach.
The keys are to have the lower hip at 0 degrees of flexion and the upper hip at 90 degrees or more. This allows the thoracic spine to rotate without any movement from the lumbar spine. This is key in all thoracic mobility drills.
- ½ Kneeling T-spine Rotation:
- Prisoner SLDL (Stiff-Legged Deadlift):
As described, the thoracic spine presents many programming challenges for the fitness professional. It’s prone to problematic excessive flexion and various issues, making it likely that it will incur further flexion throughout your clients’ lives. However, turning a blind eye to the thoracic spine’s role in kinetic chain function and instead focus on other more simple or sexy exercises does your clients an enormous disservice. Failure to address thoracic spine mechanics on a regular basis will lead to decreased results at best, injury at worst. With the simple administration of preventative and corrective measures, proper function is as likely as the great results that will come with them.
Sahrmann, S.A. (2002). Diagnosis and Treatment of Movement Impairment Syndromes. St. Louis, MO. Mosby Inc.
Clark, M.A. (2001). Performance Enhancement Specialist Manual. National Academy of Sports Medicine.
Neumann, D. A. (2002). Kinesiology of the Musculoskeletal System. St. Louis, MO. Mosby Inc.
Clark, M.A. (2000). Integrated Flexibility Training. National Academy of Sports Medicine.
Vallfors B. (1985). Acute, Subacute and Chronic Low Back Pain: Clinical Symptoms, Absenteeism and Working Environment. Scan J Rehab Med Suppl, 11, 1-98.