Principles of Structural Diagnosis
Structural diagnosis in manual medicine is directed toward evaluation of the musculoskeletal system with the goal of identification of the presence and significance of somatic dysfunction(s). It is a component part of the physical examination of the total patient. Most of the evaluation of the internal viscera takes place by evaluation of these structures through the musculoskeletal system. Therefore, it is easy to examine the musculoskeletal system while evaluating the internal viscera of the neck, chest, abdomen, and pelvic regions. Structural diagnosis uses the traditional physical diagnostic methods of observation, palpation, percussion, and auscultation. Of these, observation and palpation are the most useful. Structural diagnosis of the musculoskeletal system should never be done in isolation and should always be done within the context of a total history and physical evaluation of the patient. It has been said that 90% of a physician’s decision making is from the history and physical examination.
The diagnostic entity sought by structural diagnosis is somatic dysfunction. The three classical diagnostic criteria for somatic dysfunction can be identified with the mnemonic ART (see Chapter 1). Examples of asymmetry might be the height of each shoulder by observation, height of iliac crest by palpation, and contour and function of the thoracic cage by observation and palpation. Asymmetry is usually discerned by observation and palpation. Altered range of motion may be either restricted or increased mobility. Restricted motion is the most common component of somatic dysfunction. Range-of-motion abnormality is determined by observation and palpation, using both active and passive patient cooperation. Tissue texture abnormality (TTA) is ascertained by observation and palpation. Percussion is also used in identifying areas of altered tissue texture. A large number of descriptors are used in the literature to express the quality of the abnormal feel of the tissue. There are two primary tissue abnormalities that account for palpable changes, namely muscle hypertonicity, secondary to increased alpha motor neuron stimulation, and altered activity of the “skin viscera,” the pilomotor, vasomotor, and secretomotor functions that are under the control of the sympathetic division of the autonomic nervous system.
In structural diagnosis, it is important for the physician to maximize the coordinated use of the palpating hands and the observing eyes. When using vision for observation, it is important to know which eye is dominant so that it can be appropriately placed in relation to the patient for accuracy in visual discrimination. Since most structural diagnosis uses hand-eye coordination with the arms extended, it is best to test for the dominant eye at arm’s-length distance (Fig. 2.1). The test is as follows:
Extend both arms and form a small circle with the thumb and index finger of each hand.
With both eyes open, sight through the circle formed by the thumbs and fingers at an object at the other end of the room. Make the circle as small as possible.
Without moving your head, close your left eye only. If the object is still seen through the circle, you are right eye dominant. If the object is no longer seen through the circle, you are left eye dominant.
Repeat the procedure closing the right eye and note the difference.
When looking for symmetry or asymmetry, it is important that the dominant eye be located midway between the two anatomic parts being observed and/or palpated. For example, when palpating each acromial process to identify the level of the shoulders, the dominant eye should be in the midsagittal plane of the patient, equidistant from each palpating hand. In other words, the dominant eye should be on the midline of the two anatomic parts being compared. With a patient supine on the examining table, a right eye-dominant examiner should stand on the right side of the patient and a left eye-dominant examiner should stand on the left side of the patient. Remember that the hands and eyes should be on the same reference plane when one is attempting to determine if paired anatomic parts are symmetrically placed. For example, when evaluating the height of the shoulders by palpating the two acromial processes and visualizing a level against the horizontal plane, the eyes should be on the same horizontal plane as the palpating hands. When palpating the two iliac crests to identify if they are level against the horizontal plane, the eyes should be at the level of the iliac crests in the same plane as the palpating hands. Whenever possible, the eyes should be in the plane against which anatomic landmarks are being compared for symmetry or asymmetry.
All physicians use palpation in physical examination of the abdomen for masses, normal organs for size and position, point of maximum impulse of the heart, tactile fremitus of the lungs, and pulsations of the peripheral vessels. Palpation is also used to identify masses, normal and abnormal lymph nodes, and other changes of the tissues. In structural diagnosis, palpation requires
serious consideration and practice to develop high-level diagnostic skills. Palpatory skills affect the following:
serious consideration and practice to develop high-level diagnostic skills. Palpatory skills affect the following:
The ability to detect TTA
The ability to detect asymmetry of position, both visual and tactile
The ability to detect differences of movement in total range, quality of movement during the range, and quality of sensation at the end of the range of movement
The ability to sense position in space of both the patient and examiner
The ability to detect change in palpatory findings, both improvement and worsening, over time
It is important to develop coordinated and symmetric use of the hands so that they may be linked with the visual sense. In developing palpatory skills, one must be aware that different parts of the hands are valuable for different tests. For example, the palms of the hands are best suited for use in the stereognostic sense of contour; the dorsum of the hands are more sensitive to temperature variations; the finger pads are best for fine discrimination of textural differences, finite skin contour, and so forth; and the tips of the fingers, particularly the thumbs, are useful as pressure probes for the assessment of differences in depth.
Three stages in the development and perception of palpatory sense have been described: reception, transmission, and interpretation. The proprioceptors and mechanoreceptors of the hand receive stimulation from the tissues being palpated. This is the reception phase. These impulses are then transmitted through the peripheral and central nervous systems to the brain where they are analyzed and interpreted. During the palpation process, care must be exercised to ensure efficiency of reception, transmission, and interpretation. Care must be taken of the examiner’s hands to protect these sensitive diagnostic instruments. Avoidance of injury abuse is essential; hands should be clean and nails an appropriate length. During the palpation process, the operator should be relaxed and comfortable to avoid extraneous interference with the transmission of the palpatory impulse. To accurately assess and interpret the palpatory findings, the examiner must concentrate on the act of palpation, the tissue being palpated, and the response of the palpating fingers and hands. Reduce all extraneous sensory stimuli as much as possible. Probably, the most common mistake in palpation is the lack of concentration by the examiner.
Tissue palpation can be further divided into light touch and deep touch. In light touch, the amount of pressure is very slight and the examiner attempts to assess tissue change both actively and passively. By simply laying hands on the tissue passively, the examiner is able to make tactile observation of the quality of the tissues under the palpating hand. By moving the lightly applied hand in an active fashion, scanning information of multiple areas of the body can be ascertained, both normal and apparently abnormal. Deep touch is the use of additional pressure to palpate deeper into the layers of the tissue of the musculoskeletal system. Compression is palpation through multiple layers of tissue, and shear is a movement of tissue between layers. Combinations of active and passive palpation and light and deep touch are used throughout the palpatory diagnostic process.
It is useful to develop appropriate terms to describe the changes in the anatomy being palpated and evaluated. The use of paired descriptors such as superficial-deep, compressible-rigid, moist-dry, warm-cold, painful-nonpainful, circumscribed-diffuse, rough-smooth, among others, are most useful. It is best to define both normal and abnormal palpatory clues in anatomic and physiologic terms. Second, it is useful to define areas of altered palpatory sense by describing the state of the tissue change as acute, subacute, or chronic in nature. Third, it is useful to develop a scale to measure the severity of the altered tissue textures being palpated. Are the tissues normal or are there changes that could be identified as mild, moderate, or severe? A zero, 1+, 2+, and 3+ scale is useful in diagnosing the severity of the problem and in monitoring response to therapeutic intervention over time. Try to use descriptive language that a colleague can comprehend.
The following describes a practice session that is helpful in learning skill in layer palpation of the tissues of the musculoskeletal system. Two individuals sit across from each other with the patient’s arms placed on a narrow table (Fig. 2.2). Each individual’s right hand is the examining instrument and the left forearm is the part for the partner to examine. Starting with the left palm on the table, each individual places the right hand (palms and fingers) over the forearm just distal to the elbow.
The right hand gently makes contact with the skin. No motion is introduced by the operator’s right hand. The operator “thinks” skin. How thick or thin is it? How warm or cold is it? How rough or smooth is it? The left forearm is now supinated, and the examiner’s right hand is placed on the volar surface of the forearm in the same fashion. Again analysis of the skin is made and comparison made between the dorsal and volar aspects (Fig. 2.3). Which is the thickest? Which is the smoothest? Which is the warmest? It is
interesting to note the ability to identify significant differences between skin of one area and another by concentration on skin alone.
With the right hand firmly in contact with the skin, slight movement of the skin is made, both longitudinally and horizontally, to evaluate the subcutaneous fascia. You now concentrate on the second layer, the subcutaneous fascia. How thick is the layer? How loose is it? Note that with movement in one direction, the tissues are more “loose” and in the other direction are more “tight.” It is within this layer that many of the TTAs associated with somatic dysfunction are found.
Within the subcutaneous fascia layer are found the vessels, arteries, and veins. Palpate these structures for their identification and description.
Gently increase the pressure until you sense the deep fascia layer that envelops the underlying structures. Think deep fascia. It can be described as smooth, firm, and continuous. By palpating the deep fascia layer and moving the hand gently horizontally across the forearm, you can identify areas of thickening that form fascial compartments between bundles of muscle. The ability to define these enveloping layers of deep fascia is helpful, not only in separating one muscle from another but as a means of getting deeper into underlying structures between muscle.
Palpating through the deep fascia, you now concentrate on the underlying muscle and, through concentration, identify individual fibers and the direction in which the fibers run. Move your hands both transversely and longitudinally, sensing for smoothness or roughness. As you palpate across muscle fiber, it seems rougher, but as you move in the direction of the muscle fiber, it feels smoother. While palpating muscle, both individuals slowly open and close their left hands, energizing the muscles of the forearm. Your right hand is now palpating, contracting and relaxing muscle. Next, squeeze the left hand as hard as possible and palpate muscle during that activity. You are now palpating “hypertonic” muscle. This is the most common TTA feel at the muscle level in areas of somatic dysfunction.
While palpating at the muscle level, slowly course down the forearm until you first feel change in the tissue and the loss of ability to the discern muscle fiber. You have now contacted the musculotendinous junction, a point in muscle that is vulnerable to injury (Fig. 2.4).
Continue to course down toward the wrist, beyond the musculotendinous junction, and palpate a smooth, round, firm structure called a tendon. Note the transition from muscle through musculotendinous junction to tendon.
Follow the tendon distally until you palpate a structure that binds the tendons at the wrist. Palpate that structure (Fig. 2.5). It is the transverse carpal ligament. What are its characteristics? What direction do its fibers traverse? How thick is it? How firm is it? Ligaments throughout the body feel quite similar.
Now return your palpating right hand to the elbow with your middle finger overlying the dimple of the elbow in the dorsal side and your thumb opposite it on the ventral side to palpate the radial head (Fig. 2.6). Stay on bone, and think bone. How hard is it? Is there any “life” in it?
Now move just proximal with your palpating thumb and index finger until you fall into the joint space. Underlying your palpating fingers is a structure that you should not be able to
feel, namely, the joint capsule. Palpable joint capsules are present in pathologic joints and are not usually found in somatic dysfunction. In fact, some individuals believe that a palpable joint capsule, with the limited exception of the knee joint, is a contraindication to direct-action manipulative treatment.
You have now palpated skin, subcutaneous fascia, blood vessels, deep fascia, muscle, musculotendinous junction, tendon, ligament, bone, and joint space. After using the forearm as the model, these same structures are palpable throughout the body. Practice and experience can enhance your capability as a structural diagnostician.
Vertebral Column Muscles
The muscles overlying the vertebral column are many and layered. They can be described as follows:
Layer 1: the trapezius, latissimus dorsi, and lumbodorsal fascia
Layer 2: the levator scapulae and major and minor rhomboids
Layer 3: the erector spinae mass including the spinalis, semispinalis, longissimus, and iliocostalis
Layer 4: multifidi, rotatores, and intertransversarii
The palpation of these structures is an essential component of structural diagnosis. The following exercise in palpation might be useful in gaining familiarity with some of them for further use, both diagnostically and therapeutically.
Standing behind a seated patient, place the palms and palmer surfaces of the fingers over the shawl area of the cervicothoracic junction (Fig. 2.7). Palpate the skin for thickness, smoothness, and temperature.
Move the skin on the subcutaneous fascia overlying the deep structures in a synchronous and alternating fashion anteroposteriorly and from medial to lateral (Fig. 2.8). Note that in one direction, it will be more free and, in the other, somewhat tighter. This tight/loose characteristic is a sensation of great significance when using myofascial release technique.
Using the thumb and index finger on each hand, pick up the skin and subcutaneous fascia, and gently roll the skin over
your thumbs by the action of your index fingers coming from below upward (Fig. 2.9). Repeat starting medially and going laterally. Perform this procedure symmetrically on each side looking for differences in thickness and pliability of the skin and ascertaining if this procedure produces pain for the patient. Skin rolling that identifies tightness and tenderness is a valuable tool in identifying levels of somatic dysfunction.
Place the palm of your hand over each acromion process with the long finger extending to the anterior aspect of the shoulder girdle and the finger pad palpating the tip of the coracoid process (Fig. 2.10). Be gentle because this location is quite tender in all subjects. Palpate for the sensation of the resilience of bone. Move your finger pad slightly inferiorly to palpate the rounded, smooth, firm tendon of the short head of the biceps brachii. Return to the tip of the coracoid process, proceed medially, and palpate the broader, but still smooth and firm tendon of the pectoralis minor muscle.
Place the palms of the fingers of both hands overlying the upper thoracic region lateral to the spinous processes and medical to the scapula (Fig. 2.11). Palpate through skin and subcutaneous fascia to palpate the deeper fascia overlying the first-layer muscle, the midportion of the trapezius. Move your fingers from side to side as well as superiorly to inferiorly, sensing for muscle fiber direction. This is somewhat easier by having the patient retract the scapulae actively. Note that it appears smoother to move your hands from side to side and more rough when you move your hands from above to below. That smoothness versus roughness characteristic is typical of muscle fiber direction.
Place your left hand where your right hand was in the last example and grasp the elbow with your right hand (Fig. 2.12). Palpate through the tissues, including the horizontal portion of the trapezius, and concentrate on the next layer of muscle below, the rhomboids. The rhomboid can be more easily palpable if you resist the patient’s effort to push the elbow toward
the table. Note that the muscle has a different fiber direction than the trapezius at the same level. It is oblique from medial to lateral and from above downward. The inferior margin is easily palpable to give you the fiber direction.
Development of high-level palpation skill requires considerable practice, which is accumulated over time if a concentrated effort is made. It is also important to avoid the three most common errors in palpation, namely lack of concentration, too much pressure, and too much movement. As stated previously, the most common error is the lack of concentration on the task. The beginner frequently attempts to gain information rapidly and presses much too hard. Remember, the harder you press, the more stimulation you provide to your own mechanoreceptors, thus decreasing the amount of sensory impulse being transmitted. To demonstrate, try this simple palpatory exercise; rest the dorsum of your whole hand on the surface of a table. Using the opposite hand gently tap the table top. Notice the location(s) in your palpatory hand where you feel the vibration of tapping the table. Now press your palpatory hand more firmly into the table and notice the diminished sense of feel.
The beginner is also prone to use too much movement in searching for anatomic landmarks and in identifying layers of tissue. This is referred to as the “jiggling hands syndrome.” One must remember that the more motion exerted by the hands, the more stimulation there is in the afferent system to be transmitted and interpreted by the nervous system. Therefore, concentrate, do not push too hard, and do not move too much.
In identifying areas of somatic dysfunction by defining alterations in the diagnostic triad of asymmetry, altered range of motion, and TTA, a combination of observation and palpation is used. In palpation, both static and dynamic dimensions are present. Statically, we look for levels of paired anatomic parts to identify asymmetry. By static and dynamic palpation, we look for alterations in TTA. In palpating tissues without movement, the examiner is interested in such things as skin temperature, smoothness, thickness, and other qualifiers of the state of the tissue. In dynamic palpation, one evaluates, by compression and shear movement within the tissue, the thickness of the tissue, the amount of normal tissue tone, and a sense of which tissues are abnormal. It is within the evaluation of the range of motion that the palpatory sense becomes highly refined. Because restoration of the maximal normal amount of motion possible in the tissue is the desired end point, it is essential that we be able to identify normal and abnormal ranges of motion within both soft tissue and arthrodial structures.
Motion sense is an essential component of the palpatory art in structural diagnosis. The examiner attempts to identify whether there is normal mobility, restricted movement (hypomobility), or too much movement (hypermobility). In motion testing, the examiner may put a region or part of the body through both active and passive movement to ascertain how that part complies with the motion demand placed on it. Information is sought as to whether the mobility is abnormal in a regional sense or confined to one segment. A wide variety of techniques can be used, both actively and passively, to test for motion.
Motion Sense Palpatory Exercise
Standing aside a seated patient, palpate the midline of the upper thoracic spine overlying the spinous processes (Fig. 2.13). As you move from above downward, note that the skin is very tightly attached at the midline. As you course from above downward, you will note a bump-and-hollow characteristic. The bumps are the bony spinous processes and the hollow is the interspinous space. Note the tension of the interspinous space reflecting the tension of the supraspinous and intraspinous ligaments.
Place three fingers in the interspinous spaces of the upper thoracic spine. Introduce flexion passively through the head, sensing for opening of the interspinous spaces (Fig. 2.14). Reverse the process by taking the head and neck passively
into extension and note that the interspinous spaces narrow (Fig. 2.15). Repeat this process several times noting how the interspinous spaces open and close. Attempt to move the head and neck so that you can localize the opening of the interspinous space beneath the middle finger during flexion, but not the finger below, and repeat the same process in extension so that you can close the interspinous space under the middle finger, but not the one below. This is an important exercise in identifying your capacity to localize to a single vertebral segment.
Standing behind a seated patient, place the distal finger pads of your index finger on one side of the spinous process and your middle finger on the other and palpate the fascial groove between the spinous process and the third layer of muscle, the erector spinae mass (Fig. 2.16). Actually, the fascial plane is between the spinalis muscle, which is intimately attached to the lateral aspect of the spinous processes, and the medial side of the longissimus, the easily palpable “rope” of the erector spinae mass. As you move from cephalad to caudad in this groove, you should feel symmetry and no palpable structure. Should you palpate anything in this medial groove, it is a reflection of hypertonicity of the deeper fourthlayer muscle, primarily at the multifidus layer. Fourth-layer hypertonic muscle is rounded and tense and is about the size of a Tootsie Roll candy. They are usually quite sensitive to the patient and found unilaterally. Occasionally, a bilateral fourth-layer muscle hypertonic area can be palpated in the presence of bilateral flexion or extension restrictions of a vertebral segment. Palpable fourth-layer hypertonic muscle (the “Tootsie Roll” sign) is one of the cardinal diagnostic findings in vertebral segmental somatic dysfunction.1
Using the same distal finger pad placement as above (Fig. 2.16), again palpate the medial groove, only this time with a very light and relatively quick motion cephalad to caudad. As you glide your finger pads downward, try to perceive any horizontal bands of tissue dampness or tackiness. Autonomic nervous system changes will often be present at the same level as the vertebral segmental somatic dysfunction.2 In relatively acute situations, these areas may be perceived as areas of increase tissue texture such as bogginess, dampness, or tackiness. In more chronic situations, these may be perceived as areas of decreased tissue texture such as slickness or smoothness.
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