William E. Prentice, PhD, PT, ATC, FNATA
After reading this chapter,
the athletic training student should be able to:
- Differentiate between physiologic movements and accessory motions.
- Discuss joint arthrokinematics.
- Discuss how specific joint positions can enhance the effectiveness of the treatment technique.
- Discuss the basic techniques of joint mobilization.
- Identify Maitland’s 5 oscillation grades.
- Discuss indications and contraindications for mobilization.
- Discuss the use of various traction grades in treating pain and joint hypomobility.
- Explain why traction and mobilization techniques should be used simultaneously.
- Demonstrate specific techniques of mobilization and traction for various joints.
Following injury to a joint, there will almost always be some associated loss of motion. That loss of movement may be attributed to a number of pathologic factors, including contracture of inert connective tissue (eg, ligaments and joint capsule), resistance of the contractile tissue or the musculotendinous unit (eg, muscle, tendon, and fascia) to stretch, or some combination of the two.2,4 If left untreated, the joint will become hypomobile and will eventually begin to show signs of degeneration.26
Joint mobilization and traction are manual therapy techniques that are slow, passive movements of articulating surfaces.5 They are used to regain normal active joint range of motion (ROM), restore normal passive motions that occur about a joint, reposition or realign a joint, regain a normal distribution of forces and stresses about a joint, or reduce pain—all of which collectively improve joint function.18 Joint mobilization and traction are 2 extremely effective and widely used techniques in injury rehabilitation.1
RELATIONSHIP BETWEEN PHYSIOLOGIC AND ACCESSORY MOTIONS
For the athletic trainer supervising a rehabilitation program, some understanding of the biomechanics of joint movement is essential. There are basically 2 types of movements that govern motion about a joint. Perhaps the better known of the 2 types of movements are the physiologic movements that result from either concentric or eccentric active muscle contractions that move a bone or joint. This type of motion is referred to as osteokinematic motion. A bone can move about an axis of rotation, or a joint into flexion, extension, abduction, adduction, and rotation. The second type of motion is accessory motion. Accessory motions refer to the manner in which one articulating joint surface moves relative to another. Physiologic movement is voluntary, while accessory movements normally accompany physiologic movement.22 The 2 movements occur simultaneously. Although accessory movements cannot occur independently, they may be produced by some external force. Normal accessory component motions must occur for full-range physiologic movement to take place.8 If any of the accessory component motions are restricted, normal physiologic cardinal plane movements will not occur.10,11 A muscle cannot be fully rehabilitated if the joint is not free to move, and vice versa.26
Traditionally in rehabilitation programs, we have tended to concentrate more on passive physiologic movements without paying much attention to accessory motions. The question always asked is, “How much flexion or extension is this patient lacking?” Rarely will anyone ask, “How much is rolling or gliding restricted?”
It is critical for the athletic trainer to closely evaluate the injured joint to determine whether motion is limited by physiologic movement constraints involving musculotendinous units or by limitation in accessory motion involving the joint capsule and ligaments.13 If physiologic movement is restricted, the patient should engage in stretching activities designed to improve flexibility. Stretching exercises should be used whenever there is resistance of the contractile or musculotendinous elements to stretch. Stretching techniques are most effective at the end of physiologic range of movement, they are limited to one direction, and they require some element of discomfort if additional ROM is to be achieved. Stretching techniques make use of long lever arms to apply stretch to a given muscle.29 Stretching techniques are discussed in Chapter 8.
If accessory motion is limited by some restriction of the joint capsule or the ligaments, the athletic trainer should incorporate mobilization techniques into the treatment program. Mobilization techniques should be used whenever there are tight inert or noncontractile articular structures; they can be used effectively at any point in the ROM and in any direction in which movement is restricted.5
Mobilization techniques use a short lever arm to stretch ligaments and joint capsules, placing less stress on these structures. Consequently, they are somewhat safer to use than stretching techniques.19
Clinical Decision-Making Exercise 13-1
Following a grade 2 sprain of the lateral collateral ligament, a high jumper is having trouble regaining full knee extension. Describe a rehabilitation protocol that can help her regain full ROM.
Spin occurs around some stationary longitudinal mechanical axis and may be in either a clockwise or counterclockwise direction. An example of spinning is motion of the radial head at the humeroradial joint as occurs in forearm pronation/supination (Figure 13-1A).
Rolling occurs when a series of points on one articulating surface come in contact with a series of points on another articulating surface. An analogy would be to picture a rocker of a rocking chair rolling on the flat surface of the floor. An anatomic example would be the rounded femoral condyles rolling over a stationary flat tibial plateau (Figure 13-1B).
Gliding occurs when a specific point on one articulating surface comes in contact with a series of points on another surface. Returning to the rocking chair analogy, the rocker slides across the flat surface of the floor without any rocking at all. Gliding is sometimes referred to as translation. Anatomically, gliding or translation would occur during an anterior drawer test at the knee when the flat tibial plateau slides anteriorly relative to the fixed rounded femoral condyles (Figure 13-1C).
Pure gliding can occur only if the 2 articulating surfaces are congruent, where either both are flat or both are curved. Because virtually all articulating joint surfaces are incongruent, meaning that one is usually flat while the other is more curved, it is more likely that gliding will occur simultaneously with a rolling motion. Rolling does not occur alone because this would result in compression or perhaps dislocation of the joint.
Although rolling and gliding usually occur together, they are not necessarily in similar proportion, nor are they always in the same direction. If the articulating surfaces are more congruent, more gliding will occur; whereas, if they are less congruent, more rolling will occur. Rolling will always occur in the same direction as the physiologic movement. For example, in the knee joint when the foot is fixed on the ground, the femur will always roll in an anterior direction when moving into knee extension and, conversely, will roll posteriorly when moving into flexion (Figure 13-2).
The direction of the gliding component of motion is determined by the shape of the articulating surface that is moving. If you consider the shape of 2 articulating surfaces relative to one another, one joint surface can be determined to be convex in shape while the other may be considered to be concave in shape. In the knee, the femoral condyles would be considered the convex joint surface, while the tibial plateau would be the concave joint surface. In the glenohumeral joint, the humeral head would be the convex surface, while the glenoid fossa would be the concave surface.
Clinical Decision-Making Exercise 13-2
As a result of several recurrent ankle sprains, a gymnast has ankle instability, but she also has a buildup of scar tissue that is limiting plantar flexion. The decreased ROM is affecting her performance because most of her activity requires balance and a great deal of joint mobility. What can you do to help her situation?
This relationship between the shape of articulating joint surfaces and the direction of gliding is defined by the convex-concave rule. If the concave joint surface is moving on a stationary convex surface, gliding will occur in the same direction as the rolling motion. Conversely, if the convex surface is moving on a stationary concave surface, gliding will occur in an opposite direction to rolling. Hypomobile joints are treated by using a gliding technique. Thus, it is critical to know the appropriate direction to use for gliding.5
Each joint in the body has a position in which the joint capsule and the ligaments are most relaxed, allowing for a maximum amount of joint play.5,19 This position is called the resting position. It is essential to know specifically where the resting position is because testing for joint play during an evaluation and treatment of the hypomobile joint using either mobilization or traction are usually performed in this position. Table 13-1 summarizes the appropriate resting positions for many of the major joints.
Placing the joint capsule in the resting position allows the joint to assume a loose-packed position in which the articulating joint surfaces are maximally separated. A close-packed position is one in which there is maximal contact of the articulating surfaces of bones with the capsule and ligaments tight or tense. In a loose-packed position, the joint will exhibit the greatest amount of joint play, whereas the close-packed position allows for no joint play. Thus, the loose-packed position is most appropriate for mobilization and traction (Figure 13-3).
Both mobilization and traction techniques use a translational movement of one joint surface relative to the other. This translation may be either perpendicular or parallel to the treatment plane. The treatment plane falls perpendicular to, or at a right angle to, a line running from the axis of rotation in the convex surface to the center of the concave articular surface5,15 (Figure 13-4). Thus, the treatment plane lies within the concave surface. If the convex segment moves, the treatment plane remains fixed. However, the treatment plane will move along with the concave segment. Mobilization techniques use glides that translate one articulating surface along a line parallel with the treatment plane. Traction techniques translate one of the articulating surfaces in a perpendicular direction to the treatment plane. Both techniques use a loose-packed joint position.15
JOINT MOBILIZATION TECHNIQUES
Mobilization techniques may be used to attain a variety of either mechanical or neurophysiological treatment goals: reducing pain; decreasing muscle guarding; stretching or lengthening tissue surrounding a joint, in particular capsular and ligamentous tissue; reflexogenic effects that either inhibit or facilitate muscle tone or stretch reflex; and proprioceptive effects to improve postural and kinesthetic awareness.5,11,16,25,26
Movement throughout a ROM can be quantified with various measurement techniques. Physiologic movement is measured with a goniometer and composes the major portion of the range. Accessory motion is thought of in millimeters, although precise measurement is difficult.
Accessory movements may be hypomobile, normal, or hypermobile.23 Each joint has a ROM continuum with an anatomical limit to motion that is determined by both bony arrangement and surrounding soft tissue (Figure 13-5). In a hypomobile joint, motion stops at some point (referred to as a pathologic point of limitation), short of the anatomical limit caused by pain, spasm, or tissue resistance. A hypermobile joint moves beyond its anatomical limit because of laxity of the surrounding structures. A hypomobile joint should respond well to techniques of mobilization and traction. A hypermobile joint should be treated with strengthening exercises; stability exercises; and, if indicated, taping, splinting, or bracing.3,26
In a hypomobile joint, as mobilization techniques are used in the ROM restriction, some deformation of soft tissue capsular or ligamentous structures occurs. If a tissue is stretched only into its elastic range, no permanent structural changes will occur.
However, if that tissue is stretched into its plastic range, permanent structural changes will occur. Thus, mobilization and traction can be used to stretch tissue and break adhesions. If used inappropriately, they can also damage tissue and cause sprains of the joint.4
Treatment techniques designed to improve accessory movement are generally slow, small-amplitude movements, the amplitude being the distance that the joint is moved passively within its total range. Mobilization techniques use these small-amplitude oscillating motions that glide or slide one of the articulating joint surfaces in an appropriate direction within a specific part of the range.27
Clinical Decision-Making Exercise 13-3
Following shoulder surgery, a swimmer is having trouble regaining full ROM. His stroke will be affected if he cannot regain full extension and lateral rotation. What type of joint mobilization protocol could you implement to help him?
Maitland has described various grades of oscillation for joint mobilization. The amplitude of each oscillation grade falls within the ROM continuum between some beginning point and the anatomical limit.10,11 Figure 13-5 shows the various grades of oscillation that are used in a joint with some limitation of motion. As the severity of the movement restriction increases, the point of limitation moves to the left, away from the anatomical limit. However, the relationships that exist among the 5 grades in terms of their positions within the ROM remain the same. The 5 mobilization grades are defined as follows:
- Grade I: A small-amplitude movement at the beginning of the range of movement. Used when pain and spasm limit movement early in the ROM
- Grade II: A large-amplitude movement within the midrange of movement. Used when spasm limits movement sooner with a quick oscillation than with a slow one, or when slowly increasing pain restricts movement halfway into the range
- Grade III: A large-amplitude movement up to the point of limitation in the range of movement. Used when pain and resistance from spasm, inert tissue tension, or tissue compression limit movement near the end of the range
- Grade IV: A small-amplitude movement at the very end of the range of movement. Used when resistance limits movement in the absence of pain and spasm
- Grade V: A small-amplitude, quick thrust delivered at the end of the range of movement, usually accompanied by a popping sound, called a manipulation.7 The popping sound is caused by cavitation, which occurs due to decreased intra-articular pressure within the joint capsule that causes bubbles in the synovial fluid to pop to equalize pressure.7 Used when minimal resistance limits the end of the range. Manipulation is most effectively accomplished by the velocity of the thrust rather than by the force of the thrust.7 Most authorities agree that manipulation should be used only by individuals trained specifically in these techniques because a great deal of skill and judgment is necessary for safe and effective treatment.24,28
Clinical Decision-Making Exercise 13-4
How might a chiropractor apply the concepts of joint mobilization?
Joint mobilization uses these oscillating gliding motions of one articulating joint surface in whatever direction is appropriate for the existing restriction. The appropriate direction for these oscillating glides is determined by the convex-concave rule, described previously. When the concave surface is stationary and the convex surface is mobilized, a glide of the convex segment should be in the direction opposite to the restriction of joint movement (Figure 13-6A).17,19 If the convex articular surface is stationary and the concave surface is mobilized, gliding of the concave segment should be in the same direction as the restriction of joint movement (Figure 13-6B). For example, the glenohumeral joint would be considered to be a convex joint with the convex humeral head moving on the concave glenoid. If shoulder abduction is restricted, the humerus should be glided in an inferior direction relative to the glenoid to alleviate the motion restriction. When mobilizing the knee joint, the concave tibia should be glided anteriorly in cases where knee extension is restricted. If mobilization in the appropriate direction exacerbates complaints of pain or stiffness, the athletic trainer should apply the technique in the opposite direction until the patient can tolerate the appropriate direction.15
Clinical Decision-Making Exercise 13-5
Following an ankle sprain, accumulated scar tissue is preventing full plantar flexion. How can joint mobilization be used to help regain full ROM?
Indications for Mobilization
In Maitland’s system, Grades I and II are used primarily for treatment of pain, and Grades III and IV are used for treating stiffness. Pain must be treated first and stiffness second.11 Painful conditions should be treated on a daily basis. The purpose of the small-amplitude oscillations is to stimulate mechanoreceptors within the joint that can limit the transmission of pain perception at the spinal cord or brainstem levels.
Joints that are stiff or hypomobile and have restricted movement should be treated 3 to 4 times/week on alternating days with active motion exercise. The athletic trainer must continuously reevaluate the joint to determine appropriate progression from one oscillation grade to another.
Indications for specific mobilization grades are relatively straightforward. If the patient complains of pain before the athletic trainer can apply any resistance to movement, it is too early, and all mobilization techniques should be avoided. If pain is elicited when resistance to motion is applied, mobilization, using Grades I, II, and III, is appropriate. If resistance can be applied before pain is elicited, mobilization can be progressed to Grade IV. Mobilization should be done with both the patient and athletic trainer positioned in a comfortable and relaxed manner. The athletic trainer should mobilize one joint at a time. The joint should be stabilized as near one articulating surface as possible, while moving the other segment with a firm, confident grasp.
Contraindications for Mobilization
Techniques of mobilization and manipulation should not be used haphazardly. These techniques should generally not be used in cases of inflammatory arthritis, malignancy, bone disease, neurological involvement, bone fracture, congenital bone deformities, and vascular disorders of the vertebral artery. Again, manipulation should be performed only by those athletic trainers specifically trained in the procedure because some special knowledge and judgment are required for effective treatment.11
JOINT TRACTION TECHNIQUES
Traction refers to a technique involving pulling on one articulating segment to produce some separation of the 2 joint surfaces. Although mobilization glides are done parallel to the treatment plane, traction is performed perpendicular to the treatment plane (Figure 13-7). Like mobilization techniques, traction may be used either to decrease pain or to reduce joint hypomobility.14
Kaltenborn has proposed a system using traction combined with mobilization as a means of reducing pain or mobilizing hypomobile joints.15 As discussed earlier, all joints have a certain amount of play or looseness. Kaltenborn referred to this looseness as slack. Some degree of slack is necessary for normal joint motion. Kaltenborn’s 3 traction grades are defined as follows15 (Figure 13-8):
- Grade I traction (loosen): Traction that neutralizes pressure in the joint without actual separation of the joint surfaces. The purpose is to produce pain relief by reducing the compressive forces of articular surfaces during mobilization and is used with all mobilization grades.
- Grade II traction (tighten or “take up the slack”): Traction that effectively separates the articulating surfaces and takes up the slack or eliminates play in the joint capsule. Grade II is used in initial treatment to determine joint sensitivity.
- Grade III traction (stretch): Traction that involves actual stretching of the soft tissue surrounding the joint to increase mobility in a hypomobile joint.