Chapter 7 Chiropractic Technique

Key Words

Subluxation, mobilization, manipulation, adjustment, long lever arm, short lever arm, force, thrust, facilitation, nociceptors, somatic dysfunction, trigger points, spondylotherapy

After reading this chapter you should be able to answer the following questions:

Question 1	What has led to the multiplicity of chiropractic techniques?
Question 2	What causes cavitation? Is it a necessary outcome of manipulation?
Question 3	What distinguishes manipulation from mobilization?
Question 4	How can the amount of force be minimized in manipulative procedures?
Question 5	What are the common mechanical, soft tissue, neurologic, and psychologic effects of manual therapy?
Question 6	What is the proposed effect of chronic segmental facilitation?
Question 7	What is the rationale for the use of manual therapy to ameliorate negative somatoautonomic reflexes?

Chiropractic has maintained that the most specialized and significant therapy employed involves the adjustment of the articulations of the human body especially the spinal column. This may be done manually or mechanically, actively or passively, with the purpose of restoring normal articular relationships and function, as well as reestablishing neurologic integrity and thereby influencing physiologic processes. Although most chiropractic techniques impart a thrust, many techniques are designed to affect physiologic processes without involving the use of a thrust procedure. This chapter discusses the theory and evidence supporting these procedures.

Historical Perspective

Osseous manual thrust techniques have been used to treat various conditions since early recorded history. Records of 4000-year-old artwork from Thailand depict the use of manual therapy, as do artifacts from early Egyptian, Polynesian, Japanese, Chinese, and Native American cultures. It appears that many ancient civilizations developed various forms of manipulation for the treatment of various disease processes.^1,²

In the Corpus Hippocratum, Hippocrates (The Father of Medicine, 460-370 BC) described a form of spinal manipulation assisted by long axis distraction. The patient lay prone and was stretched by applying long axis distraction. When sufficient long axis distraction was applied, the physician would make palmar contact, reinforced by the opposite hand, over the “hump.” The doctor could then deliver a straight thrust in a posterior to anterior direction or, if indicated, change the line of correction superiorly or inferiorly (Figure 7-1). Hippocrates also described variations of this manipulative technique; instead of contacting the hump with a palmar contact, the physician could sit on the hump or even place a foot over the hump. When even more force was indicated, a board was used. With one end anchored to the wall and the middle of the board resting over the hump, the physician could push down on the free end of the board, using it as a lever to induce a posterior to anterior force onto the hump.³ Galen, Celisies, and Orbsius all used spinal manipulation techniques for various spinal deformities, neurologic deficiencies, and disease processes.

Figure 7-1 Spinal manipulation as described by Hippocrates.

(From Schoitz EH. Manipulation treatment of the spinal column from the medical-historical standpoint. Part I. Journal of the Norwegian Medical Association 1958; 78:359-72. Norske Laegeforening.)

During the Middle Ages, there exists a void in writings describing manual procedures. By the nineteenth century, a renewed interest in manual therapy was seen. In the early 1800s, Doctor Edward Harrison was renowned in London for his expertise in manual procedures. Like many others in the nineteenth century, he was shunned by his colleagues, who were more interested in practicing pharmacology and surgery.

“Bonesetters” became popular in both Europe and the United States in the nineteenth century. English bonesetters, including Hutton, Paget, Hood, Sweet, Mapp, and Barker, became famous. Herbert Barker developed such eminence as a bonesetter that in 1922 he was knighted by the Crown.

The nineteenth century was a time of turmoil and controversy in the health care world. It was this dissatisfaction with current medical practice that produced Daniel David Palmer and Andrew Taylor Still, the founders of chiropractic and osteopathy. Palmer and Still organized the knowledge of bonesetting and manual medicine into health care systems. Palmer believed in the “innate intelligence” of the brain and the central nervous system and thought that alterations in the spinal column (subluxations) interfered with neural function, thereby causing disease. Removal of the subluxation by a chiropractic adjustment was viewed as the treatment of choice. Still endorsed the osteopathic lesion and emphasized motion segment hypomobility and its effect on the vascular and lymphatic systems. Unlike Palmer’s model, Still’s model was more inclusive, taking into consideration the soft tissues as well as the primary role of the circulatory system. A major difference between Still’s early osteopathy and Palmer’s early chiropractic is that Still employed long lever arm techniques with nonspecific contacts; Palmer’s system of chiropractic consisted of short lever arm adjustments to vertebrae using specific contacts on spinous and transverse processes.

In the days of the bonesetters, knowledge and techniques were passed down from generation to generation without formal training. After Palmer organized chiropractic into a system, he opened the first chiropractic college in 1896.⁴ Many of his early students went on to establish schools of chiropractic that in turn produced students who opened other schools.

In the next century, more than 100 “named techniques” were developed.⁵ It is necessary to understand that because a wide variety of methods exists, the assumption that all forms of manual therapy are equivalent must be avoided.⁶ Many of the developed technique systems do not use high velocity low amplitude thrusts. One can only speculate about the reasons why technique systems not using thrust procedures developed. One such reason may be that certain patient presentations would either contraindicate or at least not indicate the use of a thrust technique. Examples are patients who are elderly or osteoporotic, in extremely acute pain, in later stages of pregnancy, or who have specific pathologies. Another reason might be the doctor’s inability to produce a thrusting force that is capable of making a joint change. If the doctor’s size, strength, or ability to develop the needed speed is inadequate to produce the appropriate force, some other type of technique application is necessary. Most of these “named techniques” had their origins in devoted and inquiring practitioners. These practitioners may have modified a particular technique to fit their own physical needs or to fit the needs of their subluxation conceptual model. Some observed a phenomenon of patients’ improvements and developed a technique around this phenomenon. Regardless, many of the named techniques were developed out of the desire to improve the practitioner’s ability to deliver health care.

As these named techniques sprang up, it was evident that many practitioners were creating their own language, redefining terms, and creating new words. This lack of a common language fanned the flames of miscommunication.

Terminology

As the chiropractic profession developed into the second largest health care delivery system outside of medicine, it also developed in many directions. With the lack of communication between the practitioners of different chiropractic techniques, each school of thought evolved as an independent entity. Schools expanded philosophies, refined techniques, and redefined terms. Although communication was a necessity for survival, there existed a severe communication gap. After the 1975 National Institute of Neurological Communicative Disorders and Stroke (NINCDS) Conference that evaluated the research status of spinal manipulative therapy, manual procedures were no longer considered invalid and became the object of study for a number of professions besides chiropractic. Practitioners of medicine, naturopathy, and physical therapy, in addition to osteopathy, began to study and employ manipulation and other manual techniques. The chiropractic profession was being forced to communicate with other branches of medicine, but a common language no longer existed to allow successful dialogue. Out of this dilemma, a subcommittee of the Standards of Care Committee from the Consortium for Chiropractic Research began to develop nomenclature through consensus. (See Chapter 1.) Through this consensus process, Gatterman and Hansen⁷ defined the terms manual therapy, manipulation, mobilization, adjustment, subluxation, subluxation complex, and subluxation syndrome (Box 7-1).

BOX 7-1 Manual Therapy Terminology

Manual therapy:

Procedures by which the hands directly contact the body to treat the articulations and/or soft tissues.

Mobilization:

Movement applied singularly or repetitively within or at the physiological range of joint motion, without imparting a thrust or impulse, with the goal of restoring joint mobility.

Manipulation:

A manual procedure that involves a directed thrust to move a joint past the physiological range of motion, without exceeding the anatomical limit.

Adjustment:

Any chiropractic therapeutic procedure that utilizes controlled force, leverage, direction, amplitude, and velocity that is directed at specific joints or anatomical regions. Chiropractors commonly use such procedures to influence joint and neurophysiological function.

Subluxation:

A motion segment in which alignment, movement integrity, and/or physiologic function are altered although the contact between the joint surfaces remains intact.

Subluxation complex:

A theoretical model of motion segment dysfunction (subluxation) that incorporates the complex interaction of pathologic changes in nerve, muscle, ligamentous, vascular, and connective tissues.

Subluxation syndrome:

An aggregate of signs and symptoms that relate to pathophysiology or dysfunction of spinal and pelvic motion segments or to peripheral joints.

From Gatterman MI, Hansen D. J Manipulative Physiol Ther 1994;17:302-9.

The term technique should not be confused with the terms therapy or treatment. Technique should be reserved for describing a specific manual procedure, whereas therapy and treatment include the application of the primary and ancillary procedures indicated in the management of a patient with a given health disorder. These procedures are limited by individual statutory practice acts, but they may include such procedures as joint mobilization, therapeutic muscle stretching, soft tissue manipulation, sustained and intermittent traction, meridian therapy, physiological therapeutic modalities, application of heat or cold, dietary and nutritional counseling, therapeutic and rehabilitative exercises, and biofeedback and stress management.²

Manual therapy is therefore applied in many forms, including massage, mobilization, traction, muscle energy techniques, adjustment, and manipulation. The common characteristic in all of these methods is the application of external forces to the body for the purpose of affecting the flexibility and pain-free function of the spine and its contiguous tissues.⁸ Moreover, all of these methods act on sensory receptors, usually in the region where the pain is felt or where it originates to produce a reflex response.⁹ Pain warns us mainly against harmful functioning, and it is disturbance of function that is the most common cause of pain originating in the locomotor system. Movement restriction (blockage) at the segmental level and disturbed motor patterns at the central level may serve as examples.¹⁰ The form of therapy used must vary according to the structures upon which it is to act. The optimal treatment for joint or spinal segment movement restriction is some form of manual therapy (Box 7-2).⁹

BOX 7-2 Goals of Manual Therapy

Mechanical effects

Manual therapy is thought to produce changes in the following:

• Joint alignment

• Dysfunction of motion

• Spinal curvature dynamics

• Entrapment or extrapment of a synovial fold ⁷¹

Soft tissue effects

• Changes in the tone and strength of supporting musculature

• Influencing the dynamics of supportive capsuloligamentous connective tissue (viscoelastic properties of collagen)

Neurologic effects

• Reduction in pain

• Altering motor and sensory function

• Influencing autonomic nervous system regulation

Psychologic effects

• Laying on of hands

• Placebo factor

• Patient satisfaction

Sandoz ^11,¹² defines the chiropractic adjustment as a passive manual maneuver during which the three-joint complex is suddenly carried beyond the normal physiological range of movement without exceeding the boundaries of anatomical integrity (Figure 7-2). However, various forms of manual therapy exist affecting different aspects of joint function and without the use of a thrust. (See Figure 7-2.) Regardless of the procedure used, the therapeutic emphasis is not on forcing a particular anatomical movement of a joint, but on restoring normal joint mechanics. Most forms of manual therapy result in movement of joint surfaces either actively or passively with the purpose of restoring normal articular relationships and function as well as restoring neurologic integrity and influencing physiologic processes.

Figure 7-2 Sandoz chart: Four stages of range of movement in diarthrodial joints: 1, Active range of movement (motion produced by muscular action). 2, Passive range of movement (motion produced by traction or springing the joint-joint play, up to the elastic barrier of resistance); characterizes mobilization. 3, Paraphysiologic range of movement (motion beyond the elastic barrier of resistance up to the limit of anatomic integrity produced by manipulation and accompanied by an audible release). 4, Pathologic movement (motion beyond the limit of normal anatomic integrity, which damages ligaments and capsule, resulting in joint hypermobility). Manipulation that is too forceful may move the joint beyond the limit of anatomic integrity, creating or perpetuating joint instability.

Regardless of the specific form, the goals of manual therapy include a combination of mechanical effects, soft tissue effects, neurologic effects, and psychological effects. Although these effects are usually considered or discussed separately, the division is purely academic because the effects of manual therapy cannot be specifically directed or limited. In other words, one cannot apply a manual procedure and consistently achieve a single or specified effect. For example, when using a thrust technique to create a motion or alignment change (mechanical effect), input to the joint receptors (neurologic effect) occurs, muscles and ligaments (soft tissue effect) are compressed, stretched, or lengthened, and the patient is aware that something was done (psychologic effect). Therefore these categories are developed and designed only for an easier understanding of the principles for applying the various forms of manual therapy.

Mechanical Effects

The mechanical effects of manual therapy include changes in joint alignment, dysfunctional joint motion, and spinal curvature dynamics. Generally, the mechanical effects of an adjustment will be on derangements of the somatic structures of the body that have altered joint function. Causes of altered joint function are acute injury, repetitive use injury, faulty posture or coordination, aging, congenital or developmental defects, or primary disease states. There are several causes of acute and chronic mechanical joint dysfunction (Box 7-3).

BOX 7-3 Causes of Acute and Chronic Joint Dysfunction

Meniscoid entrapment or extrapment

Muscle spasm

Displaced disc fragments

Periarticular connective tissue adhesions

Gatterman ¹³ and Rahlmann¹⁴ have reviewed the causes of joint dysfunction (subluxation) and concluded that more than one mechanism is likely to be involved in the development of joint dysfunction, although immobilization due to adhesions had the strongest literature support. Therefore all mechanisms will be considered here. (See Chapter 11.)

Intraarticular meniscoids are leaflike fibroadipose folds of synovium that are attached to the inner surfaces of the joint capsules and project into the joint cavities (Figure 7-3). These meniscoids have been found to be present in all of the posterior joints of the spine. Bogduk and Jull¹⁵ have suggested that extrapment of these meniscoids may be the cause of restricted joint motion. Upon flexion, the inferior articular process of a zygapophyseal joint moves upward, taking the meniscoid with it. Upon extension, the inferior articular process returns towards its neutral position. Instead of reentering the joint cavity, the meniscoid impacts the edge of the articular cartilage and buckles, creating a space-occupying lesion under the capsule. Pain occurs because of capsular tension and extension motion is restricted. The application of a procedure that will separate the articular surfaces may release the extrapped meniscoid.¹⁵

Figure 7-3 Position and postulated incarceration of synovial joint meniscoids. A, Diagrammatic representation of the structural components of a meniscoid in a lumbar facet. B, Meniscoids entrapment in cervical facet joints restricting extension and flexion movements. C, Entrapment of meniscoids in postulated to produce deformation of the articular cartilage surface; after reduction and over time the articular cartilage will remodel.

(Modified from Bergmann T, Peterson D, Lawrence D. Chiropractic technique. New York: Churchill Livingstone; 1993.)

Cyriax ¹⁶ espouses the belief that displaced nuclear material along an incomplete radial fissure is the source of joint fixation. Postmortem dissection studies of degenerated discs have indeed identified radial fissures in the annulus fibrosis. Nuclear migration along these radial fissures has also been demonstrated by CT discography and correlated with the patient’s pain.¹⁷ A couple of questions remain unanswered regarding the disc’s ability to restrict motion. First, annular fissures are apparently irreversible and do not mend with manipulation, yet manipulation can have an immediate and, often, lasting effect on joint dysfunction. Moreover, joint dysfunction and fixation can occur at segments where there are no intervertebral discs, such as the atlanto-occipital articulation and the sacroiliac articulations, to say nothing of the extremity joints. Finally, disc pathology can lead to spinal fixation through reflex muscle spasm. A painful and inflamed annular tear or disc herniation will cause reflex muscle spasm that restricts motion.

Specific joint derangements are thought to create a mechanical blockage of movement and an unleveling of the motion segment, resulting in tension on the joint capsule and posterolateral annulus. Because the joint capsule and posterior annulus are pain-sensitive structures, tension on these elements may reflexively induce muscle splinting with further joint restriction. Mechanical joint dysfunction is therefore considered a significant and frequent cause of spinal pain and a potential source of spinal degeneration.

A mechanical effect of manipulation that is intriguing, but not necessarily clinically important, is the process of joint cavitation. Studies performed by Roston et al.¹⁸ and Unsworth et al.¹⁹ demonstrate that as tension is applied causing a separation of the joint, there is a point where the joint surfaces jump apart, coinciding with a cracking noise. Once the tension is removed from the joint, the surfaces approximate themselves once again but at a distance slightly more apart. As the elastic barrier is passed, the articular surfaces separate suddenly, the cracking noise can be heard, and a radiolucent space appears within the joint space. The explanation of the radiolucent space rests with the fact that there is normally a small negative pressure present in a synovial joint. Its purpose is to maintain the cartilage surfaces in apposition and augment joint stability. Separation of the joint surfaces beyond the elastic barrier creates a drop in the interarticular pressure and gas is suddenly liberated from the synovial fluid to form a bubble in the joint space. The bubble bursts almost immediately with an audible crack. Analysis of the gas produced by synovial fluid cavitation was shown to consist of over 80% carbon dioxide.¹⁹

Brodeur ²⁰ has presented a slightly different model of joint cavitation and cracking based on a mechanism described by Chen and Israelachvili.²¹ Within this model, the capsular ligament plays a primary role in the production of joint cavitation and cracking. During the first phase of joint manipulation as the joint is being loaded and the joint surfaces are being distracted, the joint and the capsular ligament invaginate (draw inward) to maintain a constant fluid volume within the joint space. As distractive pressure is increased, the capsular ligament reaches its elastic limits and snaps away from the synovial fluid, producing cavitation at the capsular-synovial interface. A rapid increase in joint volume follows and the gas bubbles formed at the periphery rush to form a single coalesced bubble in the center of the joint space. Brodeur²⁰ speculates that the “snap-back” of the capsular ligament is the event responsible for the audible crack. He also proposes that this mechanism explains why some individuals with very tight or loose joint capsules do not crack:

For loose joints, the volume of the articular capsule is larger and traction of the joint does not cause a sufficient tension across the ligament to initiate the snap-back of the joint capsule. Similarly, an overly tight joint reaches the limits of its anatomic integrity before the joint capsule can begin to invaginate.

The only definitive effect of this cavitation response is the temporary increase in resting joint space. There is, however, an implication that an increase in joint range of motion occurs, but this has not been adequately established nor has the length of time for increased movement or joint space been established. There is also a placebo effect from the patient hearing the cracking noise and feeling the joint release.

There are other potential causes of noises associated with various forms of manual therapy that are not a product of cavitation. In the instance of cross linkages that have formed in traumatized soft tissues, a manual procedure can break them apart, thereby theoretically producing an audible tearing sound. With some mobilizing or manipulating procedures, the necessary movements of the parts can cause muscle tendons to move over bony protuberances, producing an audible snapping sound. Bony outgrowths can produce impingement that, with movements of the involved parts, can produce an audible clunking sound. Degenerative joint disease can produce crepitus on joint movement, producing an audible crackling sound.

Soft Tissue Effects

The soft tissue effects of manipulation include changes in the tone and strength of supporting musculature and influences on the dynamics of supportive capsuloligamentous connective tissue (viscoelastic properties of collagen). Connective tissue elements lose their extensibility with immobilization.²² With immobilization, water is released from the proteoglycan molecule, allowing con-nective tissue fibers to contact one another, which encourages abnormal cross-linking that causes loss of extensibility.²³ It is hypothesized that certain manual therapies can break the cross-linkages and any intraarticular capsular fibroadipose adhesions, thereby providing free motion and allowing water imbibition to occur. Furthermore, action of these manual therapies can stretch segmental muscles, causing spindle reflexes that may decrease the state of hypertonicity.²⁴ The effects of immobilization are summarized in Box 7-4.²⁵

BOX 7-4 Effects of Immobilization

Microscopic effects:

Loss of parallelism of collagen fibers

Distorted cellular alignment

Increased randomness of matrix organization

Increased collagen cross-link formation

Periarticular effects:

Thickening of joint capsule

Raised capsular tension

Connective tissue shrinking

Muscle atrophy

Bone demineralization

Biochemical effects:

Decreased ligament strength

Decreased lineal stiffness

Decreased energy absorbing capacity

Adapted from Akeson WH, Amel D, Woo SLY. Cartilage and ligament: physiology and repair processes. In: Nicholas JA, Hershman EB, editors. The lower extremity and spine in sports medicine. St. Louis: Mosby; 1986. p. 3-41.

After immobilization, joints become stiff. Although some stiffness results from intraarticular adhesions to surfaces that normally glide past one another,²⁶ there is also evidence that ligamentous structures can shorten (contract) and limit joint motion.²⁷ It is likely that joint stiffness results from a combination of adhesion formation between normally gliding surfaces and active changes in ligament length. Manual therapy applied to restricted joints will presumably tear the collagen cross-links and fibrous adhesions formed during joint immobilization. However, when articular or nonarticular soft tissue contractures are encountered, incorporation of procedures that minimize inflammation and maintain mobility should be considered. Viscoelastic structures are more amenable to elongation and deformation if they are first warmed and then stretched for sustained periods.²⁸ Therefore the application of moist heat, ultrasound, and other warming therapies might be considered before applying sustained manual traction or home-care stretching exercises.²

Neurologic Effects

The neurologic effects of manipulation include reducing pain, influencing spinal and peripheral nerve conduction, thereby altering motor and sensory function, and influencing autonomic nervous system regulation. Wyke ²⁹ reported that manipulative procedures can stimulate the mechanoreceptors associated with synovial joints and thereby affect joint pain. He has identified four types of joint receptors. Types I, II, and III are corpuscular mechanoreceptors that detect static position of the joint, acceleration and deceleration of the joint, direction of movement and over-displacement of the joint. The Type IV receptor is a network of free nerve endings that have nociceptive capabilities. Type IV receptors are inactive under normal conditions. However, if noxious mechanical or chemical stimulation or if Types I-III receptors are not able to function, Type IV receptors become active and the sensation of pain is perceived. If manipulative therapy can restore normal function to the joint, allowing Types I-III receptors to function, the Type IV pain receptors should be inhibited, thereby decreasing the patient’s pain. The structures most sensitive to noxious stimulation are the periosteum and joint capsule.

There is also evidence to support the concept that the spinal adjustment increases pain tolerance in the skin and deeper muscle structures, raises beta-endorphin levels in the blood plasma, and has an impact on the nerve pathways between the body wall and viscera that regulate general health.³⁰^–³⁵ Furthermore, a significant factor in musculoskeletal function is the musculature and its nerve control. Each individual will have a “postural personality” that is an expression of the individual’s muscular patterns and posture. A frequent cause of joint dysfunction may therefore be faulty neuromotor patterns due to muscular imbalance and postural strain⁹ or an inability on the part of the patient to consciously control musculoskeletal function.

There are many controversies in the application of manual therapy. Of significance is the role of pain in deciding on the appropriateness of manual procedures. Mitchell ³⁶ states that if one treats the part where the patient experiences the pain, one will be treating the wrong part of the body most of the time. He goes on to quote Osler, stating “pain is a liar.” Mitchell bases this idea on the concept that in the musculoskeletal system, pain almost always develops and persists in the structures which are stressed the most by the adaptation to the dysfunction. The opposite idea is extolled by Lewit,⁹ who states that if a manual therapy treatment is successful, it will usually produce immediate relief of pain. He adds that by far the most frequent cause of pain is disturbed function. This may involve passive joint mobility or active movement patterns. Manual therapy is directed to movement restriction of joints or motion segments of the spinal column. Pain in the locomotor system is therefore looked upon as a warning sign of harmful functioning that should be corrected in time before it causes permanent damage. Lewit also emphasizes that undiagnosed impairment of motor function is the most frequent cause of pain without a specific diagnosis, and that treatment of the pain without a thorough understanding of the functioning of the locomotor system is courting failure.⁹

Psychologic Effects

The psychologic effects of the laying on of the hands cannot be denied nor overlooked. Paris ³⁷ states that with the addition of a skilled evaluation involving palpation for soft tissue changes and altered joint mechanics, the patient becomes convinced of the interest, concern, and manual skills of the clinician. If at the conclusion of the examination, a manual procedure is performed that results in an audible “pop” or “snap,” the placebo factor will be undeniably high. Paris³⁷ states that some patients report total relief within a second or two following such a procedure which he considers far too short a time for any genuine benefit to be appreciated. The astute clinician accepts and reinforces this phenomenon, recognizing that the patient is in need of all possible assistance. It should be noted, however, that the response rate to manipulative treatment cannot be totally accounted for by the placebo effect.

Moreover, the body and mind are not separate, but really one system coordinated by the neuropeptides.³⁸ The tendency in the health care delivery system is to deal primarily with the physical aspects of health and ignore the emotional dimension—thoughts, feelings, the spirit, the soul. Today’s health care provider should recognize the interconnectedness of all aspects of human emotion and physiology. The skin, the spinal cord, and the organs are all nodal points of entry into the psychosomatic network.

Joint Assessment Procedures

Primary health care providers, with whom patients can consult, must as portal-of-entry physicians use findings derived from the case history, physical examination, clinical laboratory, and indicated special testing procedures to assess the patient’s state of health and determine the nature and cause of any ailments. The steps leading to a decision about how and what to treat are the most important part of any interaction between a doctor and a patient.¹ The differentiation of many conditions responsible for joint pain, including distinguishing an intervertebral disc lesion from facet or articular involvement, is sometimes based upon clinical intuition rather than true objective procedures. This is especially the case when the back pain is not typical for either. However, the chiropractic spinal examination and joint assessment set chiropractic apart from other areas of the healing arts. Knowing how complex the human body is, specifically the neuromusculoskeletal system, it wouldseem inappropriate to use a single evaluative procedure to decide on the presence of a manipulable lesion. No one evaluative tool should be used or relied on to make clinical decisions.

Structured evaluation of the integrity of the joint systems of the body should be viewed in terms of a multidimensional index of abnormality. The examination of the musculoskeletal system should never be done in isolation, but should be done within the confines of the rest of the clinical evaluation. The methods used in identifying the presence of joint dysfunction (subluxation) include the usual physical examination processes of observation, palpation, percussion, and auscultation. Because of the complexity of the human body and, more specifically, the neuromusculoskeletal system, it is appropriate to employ an evaluative system that combines clinical indicators to decide on those joints in greatest need of intervention. No one evaluative procedure should be used or relied upon to make clinical decisions. The structural evaluation of the spinal column should be viewed in terms of a multidimensional index of segmental abnormality. The mnemonic PARTS (Box 7-5) is used to identify the five diagnostic criteria for identification of joint dysfunction.^2,³⁹

BOX 7-5 PARTS Mnemonic for Identifying Characteristics of Joint Dysfunction

P—Pain/Tenderness

A—Asymmetry/Alignment

R—Range of Motion Abnormality

T—Tone/Texture/Temperature of Soft Tissues

S—Special Tests

P—Pain/Tenderness. The perception of pain and tenderness may be evaluated in terms of location, quality, and intensity. Most primary musculoskeletal disorders manifest as a painful response. The patient’s description and location of pain is obtained with the location and intensity of tenderness produced by palpation of osseous and soft tissues noted. Pain and tenderness findings are identified through the procedures of observation, percussion, and palpation. Furthermore, changes in pain intensity can be objectified using Visual Analog Scales, algometers, pain questionnaires, and so forth.

A—Asymmetry. Asymmetrical qualities on a sectional or segmental level are noted. The homeostatic processes in the body seek a balance in structure and function. While the complex structure of the human body and especially its frame is never completely or perfectly symmetrical, focal changes in symmetry may be clinically significant. Body symmetry is evaluated using postural examination, static palpation, and static x-ray interpretation. This would include observation of posture and gait, palpation for misalignment of vertebral segments, and evaluation of static plain film radiographs for malposition of vertebral segments.

R—Range of Motion Abnormality. Changes in active, passive, and accessory joint motions are noted. These changes may be identified as an increase or a decrease in mobility. It is thought that a decrease in motion is a common component of joint dysfunction. Global range of motion changes are measured with inclinometers or goniometers. Segmental range-of-motion abnormalities are identified through the procedures of motion palpation and stress x-ray. The mechanical assistance of a moving table section can be used to assess passive joint movement as well. The advantage of this procedure is adding the assessment of long axis distraction movement in the spine joints.

T—Tissue Tone, Texture, Temperature Abnormality. Changes in the characteristics of contiguous and associated soft tissues including skin, fascia, muscle, and ligament are noted. These changes are identified through the procedures of observation, palpation, instrumentation, and tests for length and strength.

S—Special Tests. Those testing procedures that are specific to a technique system are performed (e.g., leg check, arm fossa test, therapy localization). Additionally, visceral relationships are considered as well as other testing procedures deemed necessary from data previously obtained.

The findings derived from the PARTS evaluation can be used to decide which areas are in need of an adjustment. The clinical decision as to whether an adjustment will be made, how it is done, where and when it is applied can be determined by which area has the most findings from each category. Minimum findings can be established, that is, one from each of the first four categories. Furthermore, the examination of the musculoskeletal system should never be performed in isolation, but should be done within the context of the history and physical examination of the patient.

If the examination is inadequate, failing to reveal the source or the extent of the problem, treatment cannot be maximally effective. Moreover, the use of joint assessment procedures should comprise part of a critical continual assessment of the patient so that the effects of care can be monitored. Perceiving when to stop is as important as knowing how to start and recognizing whether to continue. Even if a complete and thorough examination can be completed during the first visit, signs and certainly symptoms must be rechecked during the course of treatment to determine the extent of patient progress. This ongoing evaluation and assessment forms the basis for treatment modification and is a key factor in total patient management. The initial examination, no matter how thorough, cannot be expected to provide all the answers. A treatment trial should be instituted with effects assessed to determine whether it should be continued or a different plan devised. It is the examination that forms the foundation for treatment, guiding the doctor in selecting appropriate treatment techniques, frequency, and course. If practitioners were to standardize their evaluations, comparisons of treatment effectiveness and efficiency could be done.

Characteristics of the Adjustive Thrust

Whereas manual therapy is a term broadly used to define the therapeutic application of a manual force (see Chapter 1), chiropractors emphasize the application of specific adjustive techniques.⁴⁰ Chiropractic manipulation is a unique form of manipulation characterized by a specific high-velocity, short-amplitude thrust.⁴¹

It is necessary to understand that a wide variety of methods exist so that the assumption that all forms of manipulations are equivalent can be avoided.⁴¹ Factors that influence the selection of manipulative procedures include age of the patient, acuteness or chronicity of the problem, general physical condition of the patient, clinician’s size and ability, and effectiveness of previous therapy, present therapy, or both. Other factors to consider are knowledge of the local anatomy, including the geometric planes of the articulations, the nature of the condition and presence of comorbidities, and the mechanical characteristics of the manual procedure. These factors determine whether to use a long or short lever procedure, the positioning of the patient, specific contact points, the magnitude and vector of the force, and the type of thrust. Box 7-6 lists the factors governing the selection of adjustment methods.⁴²

BOX 7-6 Factors Governing the Selection of the Specific Application of Manual Therapy