Pain is the localized sensation of discomfort, distress, or agony reported by an individual. ⁹ By contrast, tenderness is defined as abnormal sensitivity to touch or pressure. ⁹ Although these reports are subjective signs, a skilled and experienced doctor can feel the tissue changes that correspond with patients’ feeling pain and tenderness. Identifying whether the pain lingers after the pressure of palpation is removed is significant. Pressure over inflamed tissues causes a lingering pain. Pressure and challenging the end resistance of a dysfunctional but noninflamed joint will hurt only while the pressure is applied. As a general rule, inflamed joints should not be adjusted until the inflammation has subsided and the postinflammatory pattern of joint dysfunction has appeared. Pain can occur with vibration, such as placing a tuning fork over a bone fracture. Traction and compression can elicit pain that is mild at rest; once again, whether it lingers is significant. The chiropractor can use various reliable and valid tools to measure and quantify pain. These tools include self-administered pain and functional questionnaires, algometry (the measurement of pressure or painful stimuli) visual analog scales (VAS), pain scales, pain diagrams, and pain drawings.

Gross range of joint motion can be measured by using an inclinometer, protractor, ruler, plumb line, and various computerized methods. Ultrasound and motion x-ray studies have been used to observe and measure the complex intersegmental movement of spinal and extremity joints. Various systems of motion palpation have been described, and until an article by Marcotte and colleagues, ¹⁰ interexaminer reliability has been a major concern. Joints move, and the chiropractor can palpate that movement, but agreeing on which joints are not moving fully and by what degree of dysfunction has been a challenge. Many chiropractors use motion palpation to determine the joints to be adjusted and the line of drive (direction of dynamic thrust) they introduce into the joint complex. Other chiropractors simply use these records of the ranges of joint motion for evaluating a patient’s progress.

Active gross movement (the range-of-joint motion possible through the patient’s voluntary effort) is tested first. Passive gross movement is then tested, with the doctor pressing the range a little further. Accessory joint movements are tested at the end of the passive range of motion by springing further to see if a little elasticity is present, called the springy end feel. Intersegmental motion of spinal joints is well described in texts on biomechanics. The goal for all doctors of chiropractic is to be able to assess these rotations around the orthogonal axes to determine the correct adjustments to restore normal active, passive, and joint play movement. Many chiropractors use motion palpation to determine the specificity of the thrust into the directions of resisted end feel in a spinal motion unit or extremity joint. This procedure is demonstrated later in this chapter.

Tissue tone is determined by palpation, observation, instrumentation, and tests for the length and strength of muscles. The doctor should be able to palpate nodules to determine if they are loose or attached to bone, ligament, or tendon. In some areas, nerves are palpable, such as the ulnar nerve in the forearm. Classical diagnosis considers the liver palpable when it is enlarged, as are the lymph nodes, arterial pulses, and some hernias. The biceps tendon can be palpated when it slips out of the biceps groove of the humerus.

None of these skills are natural to a student, and perseverance is needed to become a professional. Soft, skillful hands convey an important sense of confidence to a patient, which promotes relaxation and minimizes guarding resistance to being adjusted. Short or hypertonic muscles will restrict the joint motion of the agonist, and these shortened antagonists will often be full of palpable nodules that need specific treatment before normal, active ranges of motion can be attained. A hamstring or quadriceps can feel similar to a ridged washboard because of these adhesions from past tears. Tissue swelling is easy to visualize, but by using palpation, the doctor can determine whether pitting edema is present. The fluids drawn into the legs by gravity in certain heart and kidney diseases causes pitting after pressure is applied. Joint effusion is a tight swelling and is quite painful when tested for pitting. Palpation of the deep muscles in the neck will often reveal a knotted feeling in the specific muscle responsible for a patient’s cervicogenic headache (see Chapter 24). These very common headaches often disappear when corrected by joint adjustment/manipulation and soft tissue procedures targeted at the chronic muscle spasm that has been identified through skilled palpation. Identifying normal and abnormal tissue characteristics is an art worth practicing and mastering.

Special tests include additional physical examination, laboratory procedures, or both, which aid in the differential diagnosis of joint dysfunction. Examples include orthopedic and neurologic tests, diagnostic imaging procedures, blood and urine testing, and electrodiagnosis. Testing procedures specific to a technique system, such as leg-length assessment, specific radiographic marking techniques, and particular muscle testing procedures, should also be considered.

Static palpation of bony landmarks of the spine and pelvis includes assessment of spinous, transverse, and mammillary processes of the vertebrae and of the posterior superior iliac spine (PSIS), ischial tuberosities, and iliac crest contours of the innominate bones. Bony landmarks such as femoral condyles, olecranon processes, and greater trochanters are examples of bony landmarks commonly palpated around extremity joints. The evaluator should note any asymmetries or anomalies while keeping in mind that positional faults are unreliable and should be confirmed with additional evaluation procedures.

Palpatory tenderness has been shown to be a reliable method for identifying the adjustive lesion.^{19202122 and 23} However, a difference exists between palpation of pain and tenderness and tactile palpation. Tactile palpation provides thermal and mechanical information that aids in structural assessment and may correlate with previous examination and historical findings. Tenderness palpation, on the other hand, may help distinguish healthy from unhealthy tissues. ¹² Healthy tissues can usually tolerate greater pressure than can injured or diseased tissues. In the absence of a destructive lesion, these tissue changes are important indicators of joint subluxation or dysfunction that may respond to manual treatment procedures.

Layer palpation is a systemic method of assessing the mobility and condition of myofascial and other soft tissue structures. ²⁴ Palpation begins with the most superficial structures and proceeds to deeper tissues. Light palpation with the pads of the fingers is used to assess superficial tissues (Fig. 10-1). Deeper structures require increased pressure and should be performed in a firm but gentle manner. Anatomic landmarks commonly palpated are listed in Table 10-1.

On palpating the paraspinal tissues and myofascial structures of the extremities, areas of focal irritation with discrete palpable thickening or muscle contraction are commonly felt. These taut and tender fibers, or trigger points, can be found in the long paraspinal muscles, shoulder girdle muscles (infraspinatus, supraspinatus, trapezius, rhomboid, and levator scapulae), the pelvis (iliopsoas, piriformis, quadratus, gluteal, and tensor fascia lata), and extremity muscles (extensor carpi radialis, vastus medialis, and soleus).25^{26 and 27}

Myofascial trigger points can be identified by flat or pincer palpation.²⁷ During flat palpation, the palpator’s fingertips move the patient’s subcutaneous tissue and skin across the taut muscle fibers. Pincer palpation is performed by grasping the muscle belly between the thumb and fingers while gently squeezing the tissues with a back-and-forth motion to locate taut bands. Fig. 10-2 demonstrates pincer palpation of the common wrist extensor muscle group.

A widely held view on the primary effect of the adjustment is that it increases the range of motion of a joint. ^13,15,17,28 The location and characteristics of the altered or restricted joint movement (fixation) must therefore be determined before an adjustment/manipulation can be performed. The primary technique for this evaluation is the dynamic (motion) assessment of the various joints of the spine, pelvis, and extremities. Specific techniques for palpating motion in joints can be divided into active, passive, and accessory movements (see Box 10-3).

Normally a joint will move through a certain range of active motion. The patient performs active movements while the examiner guides the patient through a particular motion. The patient’s voluntary muscle contraction causes the joint to move, and the clinician evaluates associated periarticular soft tissues for tension and resiliency. At the end of active motion, the clinician can passively push the bony lever (e.g., spinous process), thereby further assessing the quality of resistance, called end play or end feel. Springing of the joint and the determination of end play are an integral part of the examination preceding adjustment/manipulation (Fig. 10-3).

Joint play assessment “is the qualitative evaluation of the joint’s resistance to movement when it is in a neutral position.”¹³ Joint play exists because the articular surfaces do not perfectly fit. The incongruent articular surfaces also prevent a fixed axis of rotation from occurring during joint motion. The joint capsules and ligaments remain somewhat lax to allow for rolling and gliding of the articular surfaces to accommodate for the changing axis of rotation around these irregular surfaces. The joint demonstrates joint play in the neutral position, when it is under the least amount of stress, with the joint capsule and ligaments in the position of greatest laxity (Fig. 10-4). An active range of motion produced by voluntary muscle contraction follows this joint play near the neutral position. The end point of the active range of motion is called the physiologic barrier⁷ (see Fig. 10-4).

If active range of motion is under the control of the musculature, passive movements are involuntary. Passive range of motion is defined as “movements carried through by the operator (clinician) without the conscious assistance or resistance of the patient.”¹³ The passive range of motion can be greater than the range of active joint movement (see Fig. 10-4). During active movements, the muscles move the joint to the physiologic barrier. Further movement past this barrier, into the end-play zone, is produced by additional overpressure performed by the examiner (see Figs. 10-3 and 10-4). The end-play zone, or increase in passive resistance, is thought to result from the elastic properties of the joint capsule and periarticular soft tissues. If the examiner were to release the pressure while stressing the tissues in the end-play zone, the joint would spring back to its physiologic barrier. Movement beyond the end-play zone is typically associated with an audible “cracking” noise followed by slight increase in the range of motion and has been referred to by Sandoz²⁹ as the paraphysiologic space. Movement into the paraphysiologic space is within the normal boundaries of the joint and does not cause joint injury. At this point, another barrier is encountered, called the anatomic barrier. Further movement beyond this point will damage anatomic structures associated with the joint (see Fig. 10-4).