Think Outside the Box and Spine (Part 6): Shoulders and Elbows

By Kevin M. Wong, DC

During the course of this series of articles, of which this is the sixth and final installment, I have enjoyed teaching you about the kinematic chain from the ground up: feet, ankles, knees, hips, wrists and hands.

From the beginning, I have tried to paint a clear picture of how biomechanical problems that begin in the extremities can affect the entire axial kinematic chain clear up to the head. I hope you have found the journey insightful and useful for your practice thus far.

Now, our focus shifts to the shoulders and elbows. We all realize how important these upper extremity areas are and we experience this on a daily basis in the patients we treat. In the Oct. 7, 2011 issue of DC, I wrote an article called "Shoulder Pain: Practical Tips for Examination and Treatment." I went into specific details in a discussion on the shoulder that we will not delve into for this article. Here, let's specifically address the major misalignment patterns and concepts to keep in mind when treating your patients.

The Shoulder

The shoulders are an extremely common area in which to have pain and dysfunction. Frequently we see patients who have come from some other type of health care practitioner. Orthopedists, neurologists and physical therapists are a few of the health care providers who treat a the lion's share of shoulder maladies.

Shoulder pain manifests itself in confusing ways. Patients can have pain from the shoulders move into their arm, upper back, mid-back and/or neck. Headaches can eventually start as well (because of the trapezius muscle insertion into the skull). Lingering cervicothoracic pain that is not going away is a good indicator of shoulder problems. You need to be checking this.

In our society, most health care providers and patients are solely focused on "single-incident trauma" or "What just happened to you? How did you hurt yourself?" Practice teaches us that more often than not, our patients do not know how they came to have pain. Some patients are able to identify specifically how they were hurt, but for many more, the pain develops over time for various reasons or no perceived reason at all. This is where your detective skills come into play.

There are quite a few classic conditions involving the shoulder; frozen shoulder, impingement syndrome, bursitis, capsulitis and tendonitis are some of the major ones. The unifying theme with almost all shoulder conditions is the fact that the shoulder joints are misaligned. Without getting them into a better position through adjustments, rehabilitation will be hampered.

Shoulder Anatomy, Subluxation Patterns and Adjustments

Most of your patients do not understand that the shoulder joints consist of more than just the ball and socket. In fact, a lack of understanding and treatment of the other joints of the shoulder will not bring about healing as quickly. As we review the shoulder girdle joints, picture yourself or your patient slumping forward into bad posture. This gives you a feeling and a visual of how these joints will misalign.

Glenohumeral ((shoulder) joint: A multi-axial synovial ball-and-socket joint between the glenoid fossa of the scapula (shoulder blade) and the head of the humerus (upper arm bone). A shallow socket, it requires the presence of a fibrocartilaginous labrum to aid in support. The glenohumeral joint subluxates anterior - inferior (AI). The appropriate adjustment is anterior to posterior, inferior to superior. (Figure 1)

Acromioclavicular (AC) joint: The junction between the acromion process and the distal clavicle. The AC joint allows the arm to be raised above the head. It is a gliding synovial joint that acts as a pivot point for movement of the scapula. When the AC joint subluxates, the distal clavicle moves superior. Adjust the distal clavicle superior to inferior (S to I). (Figure 2)

Sternoclavicular (SC) joint: A synovial joint composed of the sternal end of the clavicle and the upper and lateral part of the cartilage of the first rib. They are separated by an articular disc. When this joint subluxates, the proximal clavicle moves superior, anterior, medial (SAM). Adjust the proximal clavicle posterior-inferior-lateral (SAM to PIL). (Figure 3)

Scapulothoracic joint: This is actually more commonly referred to as an articulation rather than a true joint. It is formed between the anterior scapula and the posterior thoracic ribs 2-7. The musculotendinous attachment to the skeleton is formed by the trapezius and serratus muscles. In terms of subluxation, an external rotational pattern is common, as they follow the shoulder anteriorly. Internal rotation pattern is possible. Use your motion palpation and movement patterns to find out. Adjust from external rotation to internal rotation. (Figure 4)

Rib joints (costovertebral, costotransverse and costosternal): Costotransverse joints are synovial and involve the facets of the tubercles of ribs 1-10, forming joints with the corresponding thoracic vertebrae. They are present in ribs 1-10. The costovertebral and costotransverse joints are found posteriorly, also in ribs 1-10. Ribs 11 and 12 are floating. The subluxation pattern for both anterior and posterior ribs is superior. Adjust superior to inferior on the rib head (S to I). (Figure 5)

The pictures above have the patient lying supine. In this case, you can use the drop table or apply directional pressure with your fingers to gently move the bone. If you don't have a drop table, use a speeder or toggle board as a portable drop piece. You can also pull out your spring-loaded instrument and place the tip on the appropriate bone in the correct direction.

Most of us learned traditional manual adjustments for the shoulder as taught in school. These methods do work. I caution you to make sure you are careful with how much force you use, as the shoulder joints are often tender and patients have a tendency to tighten up. The bottom line is to do what works for you and use the methods I discussed above to add to your tool belt.

The Elbow

Last, but not least, is the elbow joint. It is a synovial hinge joint between the humerus in the upper arm, and the radius and ulna in the forearm, allowing the hand to be moved toward and away from the body. The radioulnar joint shares joint capsule with the elbow joint, but plays no functional role at the elbow. The elbow region includes the olecranon process and the lateral and medial epicondyles.

The elbow joint moves through flexion, extension, supination and pronation. The pain felt here is often due to overuse, as well as biomechanical dysfunction of surrounding bones. We see ailments like medial and lateralepicondylitis (golfer's and tennis elbow) and bursitis, to name a few. Misalignments of the elbow region involve the radial head and the olecrenon process. (Figure 6)

Subluxation Patterns and Corresponding Adjustments

Radial head in pronation: Support the mid-forearm with the inferior hand. Gently grasp the elbow with the superior hand, placing the thumb on the radial head and the fingers wrapping around to the front of the elbow. Passively rotate the forearm from pronation to end range of supination and thrust gently. Often a "pop" can be heard. (Figure 7)

Radial head in supination: Same setup as above, except in this case, you rotate the forearm from supination to pronation and thrust gently. (Figure 8)

Olecrenon posterior: Inferior hand is on the forearm, and the contact hand has the thumb, index and middle fingers contacting the olecrenon process. Now you are moving the forearm into extension. Do not go to full extension! Leave a slight bit of flexion in the elbow as you thrust gently on the olecrenon process. (Figure 9)

As I discussed in my previous article on the wrist/hand (part 5 of this series), if you find elbow issues, always check the shoulders and neck. They are usually linked.

That brings us to the end of our comprehensive look at the extremities. I hope you have gleaned some tidbits you can use in your practice to help your patients. Feel free to contact me if you have any questions.

The Real Cause of Iliotibial Band Syndrome

By Thomas Michaud, DC

Iliotibial band syndrome is a common injury, occurring in up to 12 percent of all runners.¹ The pain associated with this syndrome is often described as "burning" and is reproduced clinically with Noble's test, in which the examiner compresses the distal band against the lateral femoral condyle while the knee is flexed 30 degrees.

Although early research suggested the iliotibial band produced injury by snapping back and forth over the lateral femoral condyle (traumatizing the bursa trapped beneath), more recent research confirms that this theory is invalid.

In their thorough analysis of iliotibial band anatomy and function, Fairclough, et al.,²determine that what appears to be a forward / backward displacement of the band during knee flexion is actually an illusion created by alternating tensions generated by the tensor fasciae latae and gluteus maximus muscles. (Fig. 1) Using MRI, the authors conclusively prove the band does not snap back and forth, but is compressed into the lateral aspect of the femur as the knee is flexed, with peak compression occurring at 30 degrees flexion.

Fig. 1. The iliotibial band (ITB). When the knee is flexed slightly (A), the tensor fasciae latae muscle (TFL) pulls with more force than the gluteus maximus muscle (G Max), causing the anterior aspect of the ITB to become more prominent (compare B and C). As the degree of knee flexion increases (D), greater tension is created in the gluteus maximus muscle and the posterior aspect of the iliotibial band becomes more prominent (E). The shifting of tension from the anterior to the posterior fibers of the ITB (F) creates the illusion that the band is displacing forward and backward. This can be demonstrated on yourself by placing your index and middle fingers on the anterior and posterior aspects of the iliotibial band as you flex your knee through a 40° range of motion. Notice that when the leg is straight, the anterior aspect of the band is more prominent and tension gradually transitions to the posterior band when the knee flexes past 30°. Drawn from photographs in Fairclough, et al.²

Fairclough, et al., claim the iliotibial band possesses two distinct sections: a lower ligamentous component that runs between the epicondyle and Gerdy's tubercle (which functions to limit internal tibial rotation); and a proximal tendinous component extending from the hip and attaching to the lateral femoral condyle through the dense fibrous band. (Fig. 2)

Fig. 2. Anatomy of the iliotibial band. Because the iliotibial band has an extensive fascial expansion that travels deep to attach to the posterior aspect of almost the entire femur (A), tension created in the gluteus maximus and TFL creates a compressive force (B) that prevents the femur from bending during single-leg stance (C). This extensive fascial support may explain why individuals with strong hip abductors have delayed progression of medial knee osteoarthritis⁸ and why athletes with femoral shaft stress fractures should always be treated with strengthening exercises for the upper gluteus maximus, gluteus medius and tensor fascia latae muscles.

The authors claim the proximal component of the iliotibial band should be considered as a separate musculotendinous unit, suggesting the pain associated with an iliotibial band syndrome may be an enthesopathy in which tensile strain in the lower femoral attachment produces insertional bone pain (comparable to the bone pain associated with an insertional Achilles tendinitis). The authors also suggest the pain may result from repetitive compression of the highly innervated fatty tissue beneath the distal aspect of the iliotibial band. Contrary to the majority of published literature, Fairclough, et al., confirm the band itself is never inflamed, and there is no evidence of bursitis or inflammation in the distal part of the vastus lateralis muscle.

To identify biomechanical factors potentially responsible for the development of this common injury, Ferber, et al.,³ performed three-dimensional motion analysis of 35 runners with iliotibial band syndrome and compared rearfoot, knee and hip movements to 35 age-matched controls. Compared to the control group, the iliotibial band syndrome group exhibited significantly greater knee internal rotation and hip adduction, with no appreciable difference in rearfoot pronation. In fact, runners with iliotibial band syndrome had slightly reduced rearfoot eversion angles compared to the control group, which is consistent with research suggesting this injury is more likely to happen in people with high arches.

The authors state that because the band has a strong attachment to the distal femur, excessive hip adduction during stance phase increases tensile strain along the entire band, while the exaggerated knee internal rotation increases torsional strain along the distal aspect of the band. The combination of increased tensile loading from the hip and torsional loading from the knee amplifies compression of the band against the lateral knee. Because there was no difference in the angle of peak knee flexion, these authors concur with the research by Fairclough et al., questioning the validity of the sagittal plane theory in which the band snaps back and forth over the epicondyle as the knee flexes.

The detailed three-dimensional kinematic analysis performed by Ferber, et al., suggests that strengthening the hip abductors and external rotators may play an important role in the management of iliotibial band syndrome. This is consistent with research by Fredrickson, et al.,⁴who demonstrated that a six-week program of hip abductor exercises produced a 51 percent increase in muscle strength, and completely resolved symptoms in 22 of 24 runners.

While the clinical efficacy of exercises may play an important role in the management of this condition, it is also essential to evaluate hip abductor flexibility, since tightness in the tensor fasciae latae, gluteus medius, and gluteus maximus muscles may increase tensile strain on the band. In an extremely detailed cadaveric study of the effect of stretching on the iliotibial band and proximal muscles, Falvey, et al.,⁵ surgically implanted strain gauges into the iliotibial bands of 20 fresh cadavers and evaluated the effect of three different stretches on lengthening the band. They also evaluated elasticity of the tensor fasciae latae / iliotibial band aponeurosis with ultrasonography while athletes performed maximum voluntary contractions of the hip abductor musculature.

Their detailed analysis confirmed that the iliotibial band itself is extremely rigid and resistant to stretch, since it lengthened less than 0.2 percent with a maximum voluntary contraction. Because of the extreme inflexibility of the fascial component of the iliotibial band, the authors emphasize that current treatment protocols focusing on reducing tension in the band are inappropriate, since they are treating the "symptoms of the condition rather than the cause." The authors state that to be effective, tension in the muscular component of the band must be reduced with soft-tissue therapies such as massage or dry needling of myofascial trigger points.

The stretches illustrated in Figure 3 are especially helpful at lengthening the upper gluteus maximus and tensor fascia latae. As demonstrated in several studies,^6-8 performing deep-tissue massage prior to stretching allows for more rapid length gains. Of course, length gains can be enhanced with the use of various in-home massage tools, such as foam rollers and/or massage sticks. Although no studies have evaluated their usefulness, clinical experience confirms the various home massage tools enhance flexibility possibly by stretching the perimysium, which is considered a major extracellular contributor to passive muscle stiffness.

Fig. 3. Various stretches for the gluteus maximus and tensor fascia latae components of the iliotibial band. Position A stretches the upper gluteus maximus, while B and C stretch the tensor fascia latae muscle.Failure to lengthen the tensor fascia latae is a common cause of recurrent injury.

References

1. Fredericson M, Wolf C. Iliotibial band syndrome in runners: innovations in treatment.Sports Med, 2005;35:451-459.
2. Fairclough J, Hayashi K, Toumi H, et al. The functional anatomy of the iliotibial band during flexion and extension of the knee: implications for understanding iliotibial band syndrome.J Anat, 2006;208:309-316.
3. Ferber R, Noehren B, Hamill J, et al. Competitive female runners with a history of iliotibial band syndrome demonstrate atypical hip and knee kinematics. J Orthop Sports Phys Ther, 2010;40:52.
4. Fredericson M, Cookingham C, Chaudhari A, et al.. Hip abductor weakness in distance runners with iliotibial band syndrome. Clin J Sport Med, 2000;10:169-175.
5. Falvey E, Clark R, Franklyn-Miller A, et al. Iliotibial band syndrome: an examination of the evidence behind a number of treatment options. Scand J Med Sci Sports,  2010;20:580-587.
6. Hopper D, Deacon S, Das S, et al. Dynamic soft tissue mobilization increases hamstring flexibility in healthy male subjects. Br J Sports Med, 2005;39:594-598.
7. Guler-Uysl F, Kozanoglu E. Comparison of the early response to two methods of rehabilitation for adhesive capsulitis. Swiss Med Wkly, 2004;134:363-368.
8. Chang A, Hayes K, et al. Hip abduction moments and protection against medial tibiofemoral osteoarthritis progression. Arth Rheum, 2005;52:3515-3519.

Low-Compression Resistance Exercises for Back and Neck Pain Sufferers

By Joseph D. Kurnik, DC

Low-compression resistance exercises can be effective for patients with back and neck pain, particularly those with spinal injuries or degenerative conditions.

These exercises are not designed to exercise every muscle of the body at different angles or make patients more athletic (although that may happen). They are designed to generally increase overall strength, tone and well-being. If done properly, these exercises can help in preventing reinjury. A short list of specific principles follows:

• Create no harm; exercise in positions of minimal stress and according to mechanically safe postures.
• Avoid standing weight training as much as possible.
• Avoid standing extension and flexion exercises.
• If sciatic pain or numbness is present, avoid hamstring stretching.
• Avoid standing or sitting neck extension positions.
• Avoid exercises that involve raising the arms higher than shoulder level (there are exceptions, such as pulldowns).
• Avoid picking up free weights when standing or sitting.
• Avoid hard-floor-impact exercises.

Free-Weight Exercises

These exercises work the major upper-body musculature. They do not work every muscle at every angle, but they will bring circulation and increased tone to all major upper-body muscles groups. It starts with basic motions, pushes and pulls; then proceeds to isolated motions, curls and lateral raises on your back and sides.

1. Supine dumbbell floor presses, knees up. Three sets of 15 repetitions. Exercises the triceps, pectorals, anterior deltoids, lateral delts to a lesser degree. Alternate exercise: seated or supine machine presses.


2. Dumbbell rows, one side at a time, on your knees, resting on a table or bench. Three sets of 15 repetitions per side. Exercises the posterior deltoids and shoulder muscles, the rhomboids, latissimus dorsi, biceps, subscapularis. Alternative position is standing and supporting body, fixed position, with one hand on a bench or countertop. Alternate exercise: cord abduction or machine rows with chest supported.


3. Supine biceps curls while on your back, with arms at 45 degrees to 90 degrees angulation, palms up. Head is supported by pillow. Curl dumbbells to about 90 degrees at the elbows, then bring dumbbells back to the floor position. Repeat. Three sets of 15 repetitions. Exercises the biceps, forearms flexors and wrists. Alternate exercise: biceps machine curls.


4. Supine dumbbell pullovers while on your back. Holding the dumbbell with both hands above the chin, elbows slightly bent, lower the dumbbell to the floor above your head. Then bring dumbbell back to starting position. Repeat for three sets of 15 repetitions. Head should be supported by a pillow.
   
   This is not a primary chest exercise, as generally believed. Primarily, it exercises the posterior deltoids and shoulders; latissimus dorsi muscles; rhomboids; and subscapularis. Alternate exercises: 1) gym pulldowns with body positioned so the cable is at a 20-30 degree angle. Keep the head facing forward; 2) cord pulldowns off the upper door edge, keeping the face forward.


5. Lateral deltoid and upper trapezius exercise. Do this exercise one side at a time. While on your left side, head supported, light dumbbell in your right hand (palm down), laterally raise (abduct) your right arm toward the ceiling as far as you can comfortably go. Stop and then lower the dumbbell back to the hip region. Repeat 15-20 times. This completes one set for the right side. Now switch sides, lying on your right side and abducting your left arm 15-20 times. Complete 2-3 sets of 15-20 repetitions on each side.

This exercise allows you to use weight resistance in a non-vertical position, sparing lumbar compression. Its main purpose is to exercise and strengthen the lateral deltoid muscles, which tend to v with age and disease.

Resistance Abdominal Exercises

1. Supine sit-ups. With lower legs up over a chair or table, thighs at a 90 degree angle to the floor, arms crossed at chest, chin flexed toward the chest, sit up until you feel resistance and cannot flex further without strain. Return to floor. Perform three sets of 15 to 25 reps or more.
   
   This exercises the abdominal muscles, with emphasis on the upper abdominals. It flattens the low back (lumbar spine) to the floor, decreasing compressive stress. It also decreases lumbar tension and increases the size of the cord and nerve canals. Thus, it can be helpful in patients with disc disease, spinal stenosis, and facet compression and degenerative conditions.
   
   Note: If this exercise, or any other, increases symptoms, it may have to be eliminated or altered. To alter this exercise, just perform less of a sit-up. Common sense should be used. Do not force any exercise if discomfort is experienced.
   
   Alternative exercises: supine sit-ups with knees bent and feet flat; pelvic tilts with thighs at right angle to the floor; pelvic tilts with knees bent and feet flat. The pelvic tilt is an exercise designed to flatten the lumbar spine. In so doing, disc pressure is reduced, spinal canals containing spinal nerves and the spinal cord are enlarged, and the spinal nerves and cord are decompressed. The exercise consists of flattening the low back to the floor, de-rotating the pelvis and contracting the abdominal muscles.


2. Supine unilateral knee / thigh raises. While in the supine position, head supported by a pillow, knees up and feet down, raise the left knee upward as far as possible; then return the left foot to the ground. Repeat with the right knee / leg. Do three sets of 15-25 repetitions. This exercise primarily works the hip flexors and lower abdominals. For patients with low back problems, raising both knees simultaneously may increase low back pressure.

Low Back and Neck Exercises

1. Supine pelvis raises. A relatively safe low back (lumbar) exercise, lie on your back, head on pillow, knees up, feet flat on the ground. At this point, raise your pelvis and low back upward toward the ceiling. Raise upward to the point of tension or resistance, stop and then return the pelvis to the floor. Raise the pelvis slowly to a comfortable tension, not rapidly or to any point of discomfort.
   
   This exercise will contract the erector back muscles and the front of the thighs (quadriceps). It also exercises the buttock muscles. The exercise takes you from a flexed position to a neutral position, avoiding overextension of the lumbar spine.


2. Neck flexion / extension (no external resistance). Lying in the supine position with the head supported by a pillow, flex the head forward in an arc-like fashion until a gentle strain is felt. At this point, stop; then lower the head to the pillow. Perform three sets of 15 repetitions. (Note: In all supine exercising, place a pillow of comfortable thickness under your head to avoid overextension of the neck.)
   
   While lying prone on your stomach on a bed or bench, with your head hanging down at the edge of the bed or bench, extend your head / neck backward until parallel with your back. Then relax, allowing your head to hang forward. Repeat 15-20 times, 1-3 sets.

Leg / Glute Exercises

For patients with low back problems, vertical compression stress needs to be avoided. This eliminates traditional squats and lunges. However, squats with the back against the wall, without weights, holding various positions is acceptable. Other acceptable exercises include leg presses (seated) and stair climbing.

Gluteal exercises include supine pelvic raises and prone ball hip extensions (see caution regarding ball exercises below).

Other Exercises / Considerations

Ball exercises: In general, use caution with ball exercises if suffering from back and/or neck pain. The exceptions are when extension (backward bending) is painful; then you can lie over the ball in the flexed position, facing downward, stomach over the ball. However, discontinue the ball exercises if discomfort is experienced. If the patient is experiencing low back or neck pain, they should not perform any ball exercises with weights.

Rotation exercises: Regarding cross-crawl, treadmill exercises with rotating body and arm motions, caution is the word in relation to low back- and neck-related disorders. Rotation of the lumbar spine with cross-crawl and rotation exercises can be irritating to lumbar disorders with/without pathology, such as disc, facet and arthritis disorders. Back-and-forth arm motions with twisting can irritate the neck and exacerbate existing neck disorders.

Swimming / water exercises: Unfortunately, regular swimming strokes can irritate neck and low back conditions. Regular strokes involve extension motions primarily, which are compression motions. However, therapeutic water exercises can be of benefit and must be evaluated on an individual basis, based on the results of certain exercises. With low back and neck pain, it is best not to use willpower to push through pain. It is best to use finesse and adapt exercises to suit the patient's condition.

Supine decompression / thoracic conditioning: Lie on your back on the floor, with your thighs at right angle to the floor and your lower legs at right angle to your thighs, resting on a chair / table / bench. Place a pillow under your head to support good posture of your neck. Stay in this position for up to 30 minutes at a time. (Any amount of time is useful. The longer the time, the longer the period of lumbar decompression and the longer the period of thoracic extension, which can increase flexibility in the thoracic spine.)

Infraspinatus Trigger-Point Syndrome

By Perry Nickelston, DC, FMS, SFMA

Numerous musculoskeletal pain syndromes and movement dysfunctions can be related to trigger points in the infraspinatus muscle. Due to the inhibitory nature of chronic trigger points, there is eventual decreased muscle activation and tone causing poor stability in functional movement patterns.

The infraspinatus is a nasty culprit in almost everything. You can count on this muscle being a factor in every shoulder dysfunction, pain or injury, but there are even more body regions that are affected by this trigger point when the body compensates for the lack of motor control and stability.

One of the four rotator cuff stabilizers of the shoulder, the infraspinatus is prone to active, latent and satellite trigger points. It attaches medially to the infraspinous fossa of the scapula and laterally to the middle facet of the greater tubercle of the humerus. It originates by fleshy fibers from its medial two-thirds and by tendinous fibers from the ridges on its surface. The fibers converge to a tendon that glides over the lateral border of the spine of the scapula and, passing across the posterior part of the capsule of the shoulder joint, is inserted into the middle impression on the greater tubercle of the humerus. It is an external (lateral) rotator of the glenohumeral joint and adductor of the arm. The infraspinatus and teres minor rotate the head of the humerus outward (external or lateral rotation); they also assist in moving the arm backward (extension of the glenohumeral joint). However, the infraspinatus is the major external rotator.

Common sense dictates that muscles need to contract and relax for movement to occur. Without this action system, we would be immobile. The problem is in how much and how well these muscle contractions occur. When muscles are affected with a trigger point, they become inherently tighter; sort of like tying a knot in a rope naturally shortens its original length. The presence of the knot and ensuing stiffness ultimately cause a loss in range of motion. This is exactly what happens to a muscle.

All of the origin and insertion points become negatively influenced and joints lose proper mobility. Inherently, the body attempts to compensate for this abnormal motion, causing other areas to become tight and restricted. The first inclination is to stretch out the tightness in an attempt to gain flexibility because it feels good (temporarily). But it never seems to last and sometimes even feels worse afterward.

A muscle is literally numerous individual bands linked together to form a single functioning unit. When you tighten these bands, the body reacts in an attempt to protect itself from injury. When you keep stretching and pulling this tightness, the nervous system eventually sends a signal to that muscle to deactivate (decrease tone and contraction) in an attempt to prevent damage. As a result of this signal, the muscle relaxes too much and it becomes weaker and less stable. That is, until your body attempts to find that stability somewhere else and adds tightness to another region. Muscles don't function in isolation, so there are always compensations patterns that must be assessed.

The infraspinatus may have several trigger points within the muscle fibers. Each point refers pain to different zones of the body. If you assess the entire muscle when you render therapy, you will have success alleviating all referral symptoms. Referred pain patterns from infraspinatus trigger points are associated with anterior shoulder pain, biceps pain, mid-scapular pain, and even tingling and numbness into the forearm and hand. The pain can be sharp, dull, burning, aching, tingling and numb. It knows no limits in its pain patterns, so suspect it with everything.

I evaluate the infraspinatus on every patient regardless of their presenting complaint. I have yet to find a patient who did not have an issue with an underlying trigger point and/or asymmetry between left and right infraspinatus muscles. So the takeaway here is simple: Every patient should have the infraspinatus muscle evaluated. Never overlook it!

There are many scenarios that can happen in regards to dysfunctional movement patterns when the infraspinatus no longer functions at 100 percent capacity. Knotted muscles will begin to deactivate and lose tone. Therefore, they can no longer perform their role of stabilization and motor control efficiently. When the infraspinatus starts to lose tone, the shoulder will then begin to internally rotate. This is one of the primary components to the typical rounding of the shoulders associated with the upper crossed syndrome paradigm developed by Vladimir Janda.

What occurs next is a cascade of dysfunctional movement. The shoulder rounds forward and the chest tightens, and the shoulder blade rotates out, putting extra contraction on the mid-back muscles. They start to fatigue and the arm drifts forward in the socket, causing anterior compression on the humeral head. The shoulder hikes up toward the ear as the trapezius muscles tighten, acromio-clavicular joint mechanics are altered, and spinal vertebrae stability becomes a factor. All of these compensatory tight muscles can develop their own latent and satellite trigger points. Some may argue that tightness in the pectoral muscles (pec major/minor) were the initial trigger points and the infraspinatus reacted to that; well, that could very well be true. But how do you think we would address this situation, regardless of what caused the initial onset? You treat both.

Trigger points are not to be overlooked. They are not simply muscle knots that cause pain. They cause serious movement dysfunction and can be excruciatingly painful. In order to re-develop this muscle and tone it again you must remove the knots first. You can't tone a muscle that has trigger points.

How do you get rid of the trigger points? My preferred way is with deep-tissue laser therapy to help improve the cellular chemical damage caused by the trigger point. The clinical choice of therapy is up to you as the treating physician. Treatment choices are methods, and there are numerous ones to choose from depending on your area of expertise. However the primary importance is to understand the baseline principles of how they cause dysfunction. Once you know these principles, you are on the right track.

Think Outside the Box and Spine (Part 5): Those Healing Hands

By Kevin M. Wong, DC

The wrists and hands are body parts we use repeatedly throughout the day, but sadly, we generally take them for granted.

Sure, some people take the time to get their hands manicured and pampered a bit, but the actual joints and muscles of the hand get little attention, if any.

However, things change when someone begins to have pain – and having pain in the wrist or hands is quite common. In a recent study, physical therapists reported that the wrist and hand, as well as the upper back area, had the second highest injury prevalence (23 percent of their patients). This was second only to the low back as the most frequent area injured.¹

As chiropractors, we use our wrists and hands with every patient in every aspect of patient care. In daily practice, especially if you treat extremities regularly, wrist and hand pain is quite common. It can range from simple soreness to full-blown radiating pain. In an effort to understand how patients develop pain or biomechanical issues from these areas, let's take a moment to review the clinical anatomy.

Image 1: The bones of the hand.Wrist / Hand Anatomy

The wrist is said to be the most complex joint in the body. It is formed by eight carpal bones grouped in two rows with somewhat restricted motion between them. From radial to ulnar, the proximal row consists of the scaphoid, lunate, triquetrum and pisiform bones. In the same direction, the distal row consists of the trapezium, trapezoid, capitate and hamate bones. There is also involvement of the proximal portions of the five metacarpal bones of the hand. (Image 1)

All carpal bones participate in wrist function except for the pisiform, which is a sesamoid bone through which the flexor carpi ulnaris tendon passes. The scaphoid serves as a bridge between the two rows; therefore, it is often susceptible to fracture or injury. The distal row of carpal bones is strongly attached to the proximal regions of the second and third metacarpals, forming a fixed unit. All other structures (mobile units) move in relation to this stable unit. The flexor retinaculum, which attaches to the pisiform and hook of hamate on the ulnar side, and to the scaphoid and trapezium on the radial side, forms the roof of the carpal tunnel. (Image 2)

Image 2: The hand showing muscles and tendons.Common Conditions

As we know, biomechanical movement and stability of the wrists and hands are critical to normal functioning. If everything is working right, the patient is none the wiser. In practice, we see a variety of wrist ailments. Many of these ailments can be traced back to specific traumas or incidents. However, it is quite common to hear the patient relate more of an insidious onset. Common conditions patients may present with include the following:

Thumb sprain: Breaking a fall with the palm of the hand or taking a spill on the slopes with a hand strapped to a ski pole could leave your patient with a painful thumb injury. The ulnar collateral ligament may be sprained. This ligament acts like a hinge and helps the thumb to function properly.

Wrist sprain: When falling forward, especially when running or rollerblading, the natural response is to put the hands out in front to catch oneself. Unfortunately, this natural response causes a person to land on their palms, bending the wrist backward and possibly stretching or tearing the ligaments connecting the bones in the wrist.

Hand fractures: Fractures of the metacarpals (the bones in the hand just before the knuckles) and the phalanges (the bones between the joints of the fingers) are also common sports injuries. Metacarpal fractures account for 30-40 percent of all hand fractures.² The most common fracture of the metacarpals is a boxer's fracture; it usually occurs when a person strikes an object with a closed fist. With a boxer's fracture, the fifth metacarpal joint is depressed and the surrounding tissue is tender and swollen.

Wrist fracture: Wrist fractures are common both in sports and motor-vehicle accidents. The break usually occurs during a fall on the outstretched wrist. The angle at which the wrist hits the ground may determine the type of injury. The more the wrist is in extension, the more likely the scaphoid bone will break. With less wrist extension, it is more likely that the radius will break.

Distal radius fractures (Colles' fractures) are very common, and the break usually happens when a fall causes someone to land on his/her outstretched hands with the wrists in slight extension.

Scaphoid fractures occur in the carpal bones, but they are not always immediately obvious. Many people with a fractured scaphoid think they have a sprained wrist instead of a broken bone, because there is no obvious deformity and very little swelling.

DeQuervain's syndrome: This is a prevalent injury in racquet sports and in athletes who use a lot of wrist motion, especially repetitive rotating and gripping. Overuse of the hand may eventually cause irritation of the tendons along the thumb side of the wrist. This irritation causes the lining around the tendon to swell, making it difficult for the tendons to move properly.

Carpal tunnel syndrome: The carpal tunnel is a narrow, tunnel-like structure in the wrist. The floor and sides of this tunnel are formed by wrist (carpal) bones. The top of the tunnel is covered by the transverse carpal ligament.

The median nerve travels from the forearm into the hand through this tunnel in the wrist. It controls feeling in the palm side of the thumb, index finger, and long fingers. The nerve also controls the muscles around the base of the thumb. The flexor tendons that bend the fingers and thumb also travel through the carpal tunnel.

When the tissues surrounding the flexor tendons in the wrist swell and put pressure on the median nerve, they create symptoms like numbness, tingling, and pain in the lateral 3.5 digits. Symptoms of CTS include pain, numbness, and tingling in the hands. Based on a recent study, one in five symptomatic subjects would be expected to have CTS based on clinical examination and electrophysiologic testing.³

Ulnar tunnel syndrome: This syndrome causes numbness and tingling in the little finger and along the outside of the ring finger. There is entrapment or irritation of the ulnar nerve as it passes through the tunnel on the medial side of the wrist. The pisiform or hook of hamate bones can impinge the nerve, creating motor and sensory deficits.

Image 3: Lateral wrist adjustment.Evaluation / Treatment Strategies

As we have seen in other parts of the body, there is a unifying theme to many of the disorders of the wrist. Aside from the obvious signs of pain, swelling or inflammation, there exists biomechanical dysfunction of the bones. As chiropractors, we know that by adjusting the bones of the wrist and hand, we restore joint motion and improvements can occur.

Adjustments of the carpal bones are not terribly difficult. Usually, we take information from the patient's history (i.e., mechanism of injury) along with orthopedic testing and motion / static palpation. Much can be felt with your palpation, as the bones are small enough that they can be "sheared" nicely. Motion / static palpation of the wrist and hand can be done in three phases:

• With one hand, grasp the distal radius / ulna and with the other hand, grasp the proximal row of carpal bones.
• With one hand, grasp the proximal row of carpal bones and with the other hand, grasp the distal row of carpal bones.
• With one hand, grasp the distal row of carpal bones and with the other hand, grasp the proximal metacarpals.

Image 4: Posterior wrist adjustment.Due to general use of the wrist and everyday wear and tear, I often find three major patterns of wrist bone misalignment. These bones can be adjusted by contacting your thumbs and stabilizing with your other fingers. (See images depicting each adjustment.)

The scaphoid, trapezium tend to move in a lateral (radial) direction. Adjusting these bones utilizes a distraction maneuver with a lateral-to-medial prestress. With the prestress, a long-axis thrust or pull will move the bones back, often with an accompanying audible. (Image 3)

The triquetral moves medial ("ulnarward"). Adjusting this bone utilizes a distraction maneuver with a medial-to-lateral prestress. With the prestress, a long-axis thrust or pull will move the bones back with an audible. (Image 4)

Image 5: Anterior wrist adjustment.The lunate, trapezoid, capitate and hamate drop inferior. Adjusting these bones involves prestressing from inferior to superior, in essence creating more room for the carpal tunnel below. (Image 5)

Compression of the metacarpal / phalangeal joints is common due to ADLs or arthritis. Gentle distraction of all parts of the phalanges will gap the joints and provide relief and increased motion.(Image 6)

Remember, manual adjusting is never the only option. Spring-loaded instruments, a drop table or a portable speeder board also work in getting movement to the bones. Also, the patterns described above are never set in stone. Use your palpation skills and find out how the bones have moved out of position; then put them back.

Protect Your Wrists / Hands

Image 6: Phalanges adjustment.I want to end by reminding you about how strenuous and stressful our job is to the joints of our hands and wrists. Take heed of some ergonomic considerations to keep your hands and wrists in good shape for years to come. Avoid adjusting maneuvers that put your wrist in extreme extension. We are usually talking about side-posture adjustments, but it can be any of your manual adjustments. Watch your table height and have that patient roll toward you or into whatever position will help your body. Keep that wrist as straight as possible so you don't jam your carpal bones.

Chronically tight muscles in your forearms and hands can create stress on the bones and joints. Get regular muscle work or put your physiotherapy modalities / machines on your body to keep your soft tissues pliable and relaxed.

Get adjusted yourself! You have to find someone who knows how to adjust extremities so that they can work on your hands / wrists also. Our patients have shown us that when we wait and hope a problem will go away, it almost always gets worse. If you have hand / wrist / elbow pain, tightness or tendonitis, get it looked at before you have too much pain and you can't adjust your patients.

The wrists and hands do command our attention because they do so much work for us and our patients. With a little practice, it is amazing how effective we can be at helping with pain in these regions.

References

1. Holder N, Clark H, DiBlasio J, Hughes C, Scherpf J, Harding J Shepard K. Cause, prevalence, and response to occupational musculoskeletal injuries reported by physical therapists and physical therapist assistants. Phys Ther, July 1999;79(7):642-652.
2. Ashkenaze DM, Ruby LK. Metacarpal fractures and dislocations. Orthop Clin North Am,1992;23:19.
3. Atroshi I, Gummesson C, Johnsson R, Ornstein E, Ranstam J, Rosén I. Prevalence of carpal tunnel syndrome in a general population. JAMA, 1999 Jul 14;282(2):153-8.

The Biomechanics of Spondylolysis, Part 1

Is It Ever an Acute Traumatic Event?

By Arthur Croft, DC, MS, MPH, FACO

I was recently retained as a biomechanical expert in a personal-injury litigation in which a man, while stopped at a traffic signal, was struck from the rear by a police cruiser. The impact forced his car into an SUV directly in front of him. While the property damage to the police cruiser was relatively superficial as far as I could determine from photographs (no other information was available), the victim's midsized passenger car sustained significant damage to the rear bumper, trunk, lights and quarter panels, as well as rather extensive damage to the front bumper, grill, hood and front quarter panels. The damage to the rear of the SUV appeared superficial, although frame damage cannot be ruled out. It should be noted that police cruisers often have reinforced bumpers, but, even within the popular Crown Victoria model, there is a lot of variation in this modification from department to department.

The 30-year-old man complained immediately of low back pain and was transported to the hospital. In time, he underwent bi-level lumbar fusion at L3-4 and L4-5 with PEEK (poly-ether-ether-ketone) cage placement. The procedure utilized the transforaminal lumbar interbody fusion (TLIF) approach and no additional instrumentation (rods or screws) were used in the procedure. Subsequently, the man developed a rather profound lumbosacral plexopathy with very severe atrophy in both lower extremities - obviously a complication of surgery.

Interestingly, when a CT was performed later to assess the fusion integrity and, no doubt, to look for a cause of the postsurgical lumbosacral plexopathy, they discovered a bilateral pars defect at L5-S1. This apparently had not been seen earlier. I came into the case after the surgery had been performed; my primary task was the crash reconstruction and biomechanical assessment. However, I couldn't help but wonder whether the bilateral pars defects were pre-existing or represented an acute fracture due to the trauma. If they were an acute fracture, might they have been a major contributor to the man's pain? Might the surgical fusion procedure have been unnecessary? Might the man's lumbosacral plexopathy have been avoided altogether? Or, could the pars defects have developed as a consequence of the fusion?

These intriguing questions, of course, potentially invite new questions concerning the appropriateness of surgical and other treatment. And yet, the question of the acuteness of the pars defects are an issue for biomechanical assessment, as is the fusion integrity and the biomechanical stability of the PEEK cage procedure. So, I started with a search of the literature to find out what we know about the etiology of lumbar spondylolysis. Let's look at the assessment; in part 2, we'll delve into the biomechanical issues of the PEEK cage placement and provide a final denouement of my analysis.

Prevalence of Pars Interarticularis Fracture

Most of us were taught that a pars defect is a form of fatigue fracture caused by repetitive stress in the area. It is never seen in a fetus, nor is it seen in people who have never walked. It is also not seen in primates who do not walk upright. It is seen only after the age of 5 years and is most commonly discovered in teenagers and young adults. It does seem to have a genetic predisposition and is seen in up to 50 percent among certain groups of Alaskan natives. It is most often seen in athletes who do a lot of acute trunk bending or very heavy lifting, such as gymnasts, swimmers, divers, weight-lifters, fast bowlers in cricket, etc.

While some have speculated that the fractures can be the result of an acute event, little has been written on the topic. There is a report of woman sustaining a bilateral L4 pars fracture in a motor vehicle collision (MVC).¹ Details of the collision were not revealed, but she was treated with three weeks of hospitalization (this was 1978, mind you). Earlier radiographs from 1973 showed no defects, so this was presumed to be a case of acute fracture.

There is another report of a man falling over a balcony, sustaining what the authors conjectured to be an extension and compression injury to the low back.² The acute nature of this bilateral L5 pars fracture was confirmed to some extent by the radiological appearance of having no sclerotic margins initially, and a callus formation that developed after period of bed rest and bracing. The lack of history of back pain, the author thought, added confirmation of the acuteness of the injury, although many individuals with pars defects do not have back pain.

A recent sample of 3,529 participants of the Framingham Heart Study was evaluated with multidetector CT imaging to assess aortic calcification.³ The presence of spondylolysis was characterized by CT imaging. The prevalence of lumbar spondylolysis was found to be 11.5 percent, nearly twice the prevalence of previous plain-radiograph-based studies. No significant correlation was identified between spondylolysis and the occurrence of low back pain in this group. It is important, of course, to remember that the association between pars defects and low back pain may well be correlated in a population of low back pain sufferers. For example, among young athletes with pars defects, 77 percent were reported to have low back painin an earlier study.⁴ This suggests that the etiology of pars defects may vary between athletes and non-athletes.

Biomechanics of Pars Interarticularis Fracture

Fig. 1: The force Fp was applied to the inferior facet as illustrated. The force Sp, which exists normally (but not in the experiment), is that generated by paraspinal musculature. The resultant vector of those forces is one of simple tension along the neutral axis of the pars.Note, however, that bone is stronger in compression than in tension.Interestingly, spondylolysis has been seen following spine fusion.¹ Although these were older reports from the 1950s and 1960s, there was one recent report of a postsurgical pars defect developing in a patient who had been given a prosthetic disc; this was thought by the authors to be the first report of this complication in a non-fusion procedure.⁵ From a biomechanical standpoint, it is likely that fusing one or more levels would result in stress risers in adjacent mobile motor units; let's leave that to our discussion of the PEEK cage instrumentation issue in part 2 of this series.

Biomechanical studies have looked at bending of the articular processes using cadaver spine elements.⁶ They repetitively loaded the motor units in flexion and extension to simulate both bending modes, both with and without compressive loading. A load of about 1,000 N (225 lb-f) was applied initially to simulate unloaded bending. To simulate bending with compression, this load was increased to about 2,000 N. This is approximately the load induced by lifting a 25 lb weight with the back bent. (It is noteworthy that lifting with a bent back results in more shear loading and less compressive loading.) Loading was continued until the elastic limit was reached, indicating the beginning of the point of sprain of the supraspinous and interspinous ligaments. The elastic limit is determined by examination of the point on the force-deflection curve where the slope of the curve begins to flatten out, indicating an end to the linear (i.e., elastic) relationship between stress and strain.

Cyron, et al., applied loads to the inferior facets of cadaver lumbar vertebrae to impose a line of force perpendicular to the neutral axis of the pars.⁷ They produced bilateral pars fractures with forces in the 2,000 N range in most specimens using a strain rate or displacement rate of 5 cm/second. The typical time to fracture was 100 msec, which is about the point of peak occupant loading we find in rear-impact MVC tests. The applied load in these cadaver tests was consistent with an extension motion of the lumbar spine. They noted that in flexion, although the combined forces exerted by the inferior facet and paraspinal muscles would be higher than in the erect position, the resultant force of the two vectors would be tensile in nature, rather than a bending moment, and, therefore, less likely to produce significant stress in the pars.(See Figure 1.)

Biomechanically, the forces acting on the lower lumbar region are illustrated in Figure 2 (note that force vectors and moment arms are not drawn precisely to scale). For static equilibrium equations, we would have the following:

Fig. 2: The force of gravity acting through the center of gravity, cg, is the weight, W, which is greatest at L5. The origin, O, is the instantaneous axis of rotation. The effects of W and muscle force, S, are balanced by the normal force, N, the resistance to disc com-pression, and plane, P, the resistance to disc shear.In related research, Cyron, et al., demonstrated that oscillating forces between 380 N and 760 N caused fatigue fractures of the pars in about 70 percent of specimens tested, sometimes after only a few thousand cycles.⁸ Green, et al., conjectured, based on these earlier studies by Cyron, et al., ^7-8 that flexion and extension bending, unloaded, was sufficient to produce fatigue fractures based on the amount of deflections (1.3 mm) they measured.⁶ With a load, the deflections were actually lower. In agreement to Cyron, et al., however, they concluded that full extension poses a greater threat to the pars than full flexion.

Another group similarly utilized a materials testing device to load lumbar human cadaver spines.⁴ They applied compressive, A-P bending, and rotational loads to specimens without discs. Although the lack of discs may have compromised the external validity of the study, the deformations under maximum loads of 2,544 N convinced the authors that the etiology of pars defects could be acutely traumatic or due to repetitive stress producing a fatigue fracture.

Fig. 3: Based on the results of our crash tests at the Spine Research Institute of San Diego, the initial response of the lumbar spine in a rear-impact crash is flattening of the spine with flexion and compression. This is followed immediately by extension, which coin-cides with the compressive phase.So, what of the forces produced in a 15 mph rear-impact delta V collision? Recent cadaver sled tests simulating rear impacts at up to 10 mph indicate early forward pelvic rotation, which would be coincident of lumbar extension.(See Figure 3.) Our own crash tests, as well as those of others, have demonstrated a strong vertical acceleration of the lumbar and thoracic spine during the initial phase of a rear-impact crash test (i.e., the so-called vertical ramping effect). This produces a large axial compressive force in the lumbar region. In recent finite element analysis (FEA) simulations of rear-impact crashes of 15.5 mph, researchers reported the contact force between the pelvis and seat back was more than 7,000 N (close to 1,600 lb-f).⁹ This would produce a horizontal (extensile) line of force, and would coincide with ramping and compression.

The definitive study has yet to be published to answer this question concerning acute vs. fatigue fracture. To determine whether such an injury is acute vs. the fatigue fracture type requires a bone scan or SPECT study and serial radiographs to look for callus formation (although callus may not form even after an acute fracture of the pars). Biomechanical studies, on balance, indicate that most cases of pars defects will be a type of fatigue fracture. But sufficient forces can develop within the boundaries of moderate or higher speed rear-impact motor-vehicle collisions to produce acute pars fractures.

Because of rearward ejection of occupants in high-speed, rear- impact crashes, seat manufacturing specifications were changed some time ago. This has resulted in a dramatic 32 percent increase in the key spinal biomechanical responses, over a range of crash severities, with a shift from the yielding seats of the 1980-1990s to the new, stiffer benchmark seats.¹¹ Horizontal placement of seat back frame elements can result in high-force points of contact in the lumbar region, concentrating bending, shear, and compressive loads on the lumbar spine, which also bears the greatest gravitational load in the spine. The pars interarticularis is most vulnerable to this combination of loading.

References

1. Klinghoffer K, Murdock MG. Spondylosis following trauma. Clin Orth Rel Res, 1982;166:72-4.
2. Cope R. Acute traumatic spondylolysis. Clin Orth Rel Res, 1988;220:162-5.
3. Kalichman L, Kim DH, Li L, Guermazi A, Berkin V, Hunter DJ. Spondylolysis and spondylolisthesis: prevalence and association with low back pain in the adult community-based population. Spine, 2009;34(2):199-205.
4. Ichikawa N, Ohara Y, Morishita T, Taniguchi Y, Koshikawa A, Matsukura N. An aetiological study on spondylolysis from a biomechanical aspect. British Journal of Sports Medicine, 1982;16(3):135-41.
5. Schulte TL, Lerner T, Hackenberg L, Liljenqvist U, Bullmann V. Acquired spondylolysis after implantation of a lumbar ProDisc II prosthesis: case report and review of the literature. Spine, Oct. 15, 2007;32(22):E645-8.
6. Green TP, Allvey JC, Adams MA. Spondylolysis: bending of the inferior aricular processes of lumbar vertebrae during simulated spinal movements. Spine, 1994;19(23):2683-91.
7. Cyron BM, Hutton WC, Troup JD. Spondylolytic fractures. J Bone Joint Surg (British), November 1976;58-B(4):462-6.
8. Cyron BM, Hutton WC. The fatigue strength of the lumbar neural arch in spondylolysis. J Bone Joint Surg (British), May 1978;60-B(2):234-8.
9. Kitagawa Y, Yasuki T, Hasegawa J. Consideration of possible indicators for whiplash injury assessment and examination of seat design parameters using human FE model. 20th International Conference of the Enhanced Safety of Vehicles (ESV), Lyon, France, 2007.
10. Croft AC. Whiplash and Mild Traumatic Brain Injuries: A Guide for Patients and Practitioners. Coronado: SRISD Press; 2009.
11. Viano DC. Seat properties affecting neck responses in rear crashes: a reason why whiplash has increased. Traffic Inj Prev, September 2003;4(3):214-27.