CHAPTER 13 | Improving Mobility |
OVERVIEW
Normal mobility is necessary for efficient movement. The terms range of motion (ROM), flexibility, and accessory joint motion are often listed as components of mobility.
A decrease in accessory joint motion, ROM and/or in the flexibility of one joint can affect the mobility of the kinetic chain. For example, a decreased ROM or flexibility in the shoulder can impact the mobility of the entire arm. In order to provide treatment for a loss of mobility, the clinician must make the determination as to the specific cause, that is, loss of joint motion, ROM, or decreased flexibility. For example, is the specific cause due to joint effusion, adaptive shortening of connective tissue structures, a change in bony architecture, or malalignment of the articular surfaces? Attempting to perform ROM and flexibility techniques in the absence of normal arthrokinematic motion at the joint surface will not result in an improvement in the impaired mobility, but may instead increase the patient’s symptoms.
Flexibility
Flexibility is the ability to move a single joint or series of joints through an unrestricted and pain-free ROM. Flexibility depends on sound joint arthrokinematics, full ROM (normal osteokinematics), and soft-tissue extensibility. It also depends on the mechanical and neurophysiological properties of the tissues involved and how those tissues react to physical loading (see Chapters 1 and 2). Stretching techniques are designed to improve the extensibility of both contractile and noncontractile tissues, including neural tissues (see Chapter 11). Indications for stretching include those scenarios when ROM is limited due to a loss of extensibility in the soft tissues because of scar tissue formation, adhesions, and contractures that have resulted in functional limitations or participation restrictions. Contraindications for stretching include a bony end feel, an incomplete bony union, recent fracture, acute inflammatory or infectious process, sharp pain with joint movement, or in the presence of hypermobility.
When referring to flexibility, two types are recognized, static and dynamic.
In addition to those already mentioned, a number of other factors influence connective tissue deformation:
It is important to make a distinction between stretching and warm-up as the two are not synonymous but are often confused by the layman. While stretching places neuromusculotendinous units and their fascia under tension, a warm-up requires the performance of an activity that raises total body and muscle temperatures to prepare the body for exercise.24 Research has shown that warm-up prior to stretching results in significant changes in joint ROM.25 Anecdotally, it would make sense not to perform stretching at the beginning of the warm-up routine because the tissue temperatures are too low for optimal muscle–tendon function, and are less compliant and less prepared for activity. Some advocate stretching after an exercise session, citing that the increased musculotendinous extensibility leads to the potential for improved joint flexibility.26 In one study, static stretching was done before, after, and both before and after each workout. All produced significant increases in ROM.27
A variety of stretching techniques can be used to increase the extensibility of the soft tissues.
Static Stretching
Static stretching involves the application of a steady force for a sustained period. The stretch should be performed at the point just shy of the pain, although some discomfort may be necessary to achieve results.28 Small loads applied for long periods produce greater residual lengthening than heavy loads applied for short periods.41 Restoration of the normal length of the muscles may be accomplished using the guidelines outlined in Table 13-1. Weighted traction or pulley systems may be used for this type of stretching. It is important for the patient to realize that the initial session of stretching may increase symptoms.42 However, this increase in symptoms should be temporary, lasting for a couple of hours, at most.32,43
TABLE 13-1 | Static Stretching Guidelines |
Data from: aAssmussen E, Bonde-Peterson F. Storage of elastic energy in skeletal muscle in man. Acta Physiol Scand. 1974;91:385–392. bBosco C, Komi PV. Potentiation of the mechanical behavior of the human skeletal muscle through prestretching. Acta Physiol Scand. 1979;106:467–472. cCavagna GA, Saibene FP, Margaria R. Effect of negative work on the amount of positive work performed by an isolated muscle. J Appl Physiol. 1965;20:157–158. dCavagna GA, Disman B, Margarai R. Positive work done by a previously stretched muscle. J Appl Physiol. 1968;24:21–32. |
Dynamic Stretching
Dynamic stretching involves stretching by a muscular contraction to increase or decrease the joint angle where the muscle crosses, thereby elongating the musculotendinous unit as the end ROM is obtained26 Dynamic stretching is a specific warm-up using activity-specific movements to prepare the muscles by taking them through the movements used in a particular sport.26 Dynamic stretching does not incorporate end-range ballistic movements, as in ballistic stretching, but rather the use of controlled movements through a normal ROM.26
There is some debate as to whether the static or dynamic method is better to stretch a muscle. Static stretching is considered the gold standard in flexibility training.44 However, recent studies have found that static stretching is not an effective way to reduce injury rates,45,46 and may actually inhibit athletic performance.6 This is likely because the nature of static stretching is passive and does nothing to warm a muscle.47 More dynamic methods of stretching involve either a contraction of the antagonist muscle group, thus allowing the agonist to elongate naturally in a relaxed state, or eccentrically training a muscle through its full ROM.44 The latter method would appear to address the problem that most injuries occur during the eccentric phase of activity.45 A study by Nelson44 that compared the immediate effect of static stretching, eccentric training, and no stretching/training on hamstring flexibility in high school and college athletes (75 subjects) found the flexibility gains in the eccentric training group to be significantly greater than the static stretch group.
Neurophysiologic Stretching
This type of stretching refers to the use of techniques that rely on the neurophysiological changes that occur in contractile tissues. The goal of these techniques is to reduce the sensory-motor feedback and thereby increase relaxation. Such techniques include proprioceptive neuromuscular facilitation (PNF) and muscle energy (see Chapter 10). The majority of studies have shown the PNF techniques to be the most effective for increasing ROM through muscle lengthening when compared to the static or slow sustained, and the ballistic or bounce techniques,48–58 although one study found it to be not necessarily better.59
The PNF techniques of contract–relax (CR), hold–relax (HR), an agonist contraction (AC), or a hold–relax–agonist contraction sequence (HR–AC) can be used to actively stretch the soft tissues:2
Other techniques that can assist in lengthening of contractile tissue through relaxation include the following:
Following each stretching session, the stretched tissues must be allowed to cool in a lengthened position. This can be facilitated by using cold packs. Once gains in motion have been achieved, it is important for the patient to gain neuromuscular control of the agonists in the new range. This can be accomplished with low load resistance exercises throughout the newly acquired range. For example, after having stretched the hamstrings to reduce a knee flexion contracture, the patient is encouraged to activate the quadriceps in the new range. Once the ROM approaches what is normal for the patient, the muscles that were shortened and then stretched must also be strengthened.
Range of Motion
Any given muscle, crossing a single joint, is normally capable of shortening sufficiently to permit a full ROM at that joint. The functional excursion of a one-joint muscle is limited by the ROM at the joint it crosses. For example, the hip abductors are limited by the range available at the hip joint. For two-joint or multi-joint muscles, the functional excursion goes beyond the limits of any one joint that they cross. For example, the sartorius muscle can flex, abduct, and externally rotate the hip as well as being able to flex the knee. The absolute amount by which any muscle can shorten depends on:
- The length of, and arrangement of, the fibers
- Structure and design of the joint.
- The number of joints traversed.
- Resistance of antagonist muscle or muscles
- The presence of any load that opposes the muscle.
If a muscle that crosses two or more joints produces simultaneous movement at all of the joints that it crosses, it soon reaches a length at which it can no longer generate a functional amount of tension. This is referred to as active insufficiency (e.g., attempting to achieve maximal hip flexion with the knee fully extended). In contrast, when the full ROM at any joint, or joints, that the muscle crosses is limited by the muscle’s own length, it is referred to as passive insufficiency (e.g., attempting to fully extend the elbow, while simultaneously pronating the forearm and extending the shoulder places the brachialis muscle in a position of passive insufficiency).
From a rehabilitation viewpoint, to maintain or improve the amount of ROM at a joint or kinematic chain, each joint must be moved through its available ROM at regular intervals. Continuous immobilization of skeletal muscle tissues can cause some undesirable consequences, including weakness or atrophy of the muscles.61 Muscle atrophy is an imbalance between protein synthesis and degradation. After modest trauma, there is a decrease in whole-body protein synthesis62 rather than increased breakdown. With more severe trauma, major surgery, or multiple organ failures, both synthesis and degradation increase, the latter being more enhanced.63,64
When referring to ROM techniques used in rehabilitation, three major movements are recognized:2
Goniometry
The term goniometry is derived from two Greek words, gonia meaning angle and metron, meaning measure. Thus, a goniometer is an instrument used to measure angles. Within the field of physical therapy, a goniometer is used to measure the total amount of available motion at a specific joint. Goniometry can be used to measure both active and passive ROM, PROM, AAROM, and AROM.
Goniometers are produced in a variety of sizes and shapes and are usually constructed of either plastic or metal (Fig. 13-1). The two most common types of instruments used to measure joint angles are the bubble inclinometer and the traditional goniometer.
FIGURE 13-1 The various types of goniometers.
FIGURE 13-2 Bubble goniometer.
FIGURE 13-3 Extendable goniometer.
The correct selection of which goniometer device to use depends on the joint angle to be measured. The longer-armed goniometer, or the bubble inclinometer, are recommended when the landmarks are further apart, such as when measuring spine, hip, knee, elbow, and shoulder movements. In the smaller joints, such as the wrist and hand and foot and ankle, a traditional goniometer with a shorter arm is used.
The general procedure for measuring ROM involves the following:
- The patient is positioned in the recommended test position and should be correctly draped. While stabilizing the proximal joint component, the clinician gently moves the distal joint component through the available ROM until the
end feel is determined (see Chapter 4). An estimate is made of the available ROM, and the distal joint component is returned to the starting position.
- The clinician palpates the relevant bony landmarks and aligns the goniometer.
- A record is made of the starting measurement. The goniometer is then removed, and the joint is moved through the available ROM. Once the joint has been moved through the available ROM, the goniometer is replaced and realigned, and a measurement is read and recorded.
The standard testing procedures for each of the upper and lower extremity joints are outlined in Tables 13-2 and 13-3.
TABLE 13-2 | Goniometric Techniques for the Upper Extremity |
TABLE 13-3 | Goniometric Techniques for the Lower Extremity |
Goniometry of the Upper Extremity
The following sections describe in detail how to perform a goniometric measurement of the major joints of the upper extremity.
Shoulder Complex
Shoulder motion occurs at the glenohumeral, scapulothoracic, acromioclavicular, and sternoclavicular joints. In addition, for full shoulder motion to occur, they must also be available motion in the cervical and upper thoracic spine. For the following measurements, the patient is positioned in supine with both hips and knees flexed and the feet placed on the bed to flatten the lumbar spine unless otherwise stated.
Shoulder Flexion. When measuring glenohumeral flexion, allowing the motion to occur at the other joints provides a more functional reading. However, if the clinician requires a measurement of pure glenohumeral motion, the other joints must be manually blocked. This is best achieved by stabilizing the scapula to prevent it from elevating, upwardly rotating, and posteriorly tilting. In the following description, the scapular is not stabilized; instead the thorax is stabilized to prevent extension of the spine.
Upper Extremity Position. The glenohumeral joint is initially positioned at 0 degrees of abduction, adduction, and rotation, and the forearm is positioned in 0 degrees of supination and pronation so that the palm of the hand faces the body.
Goniometer Placement. The fulcrum is centered close to the acromion process, the proximal arm is aligned with the midaxillary line of the thorax, and the distal arm is aligned with the lateral midline of the humerus, using the lateral epicondyle of the humerus as a landmark.
Technique. The shoulder is moved passively or actively to the end range of available shoulder flexion (Fig. 13-4), and a measurement is made (Fig. 13-5).
FIGURE 13-4 Passive shoulder flexion.
FIGURE 13-5 Goniometric measurement of shoulder flexion.
Shoulder Extension. The patient is positioned in prone.
Upper Extremity Position. The glenohumeral joint is positioned at 0 degrees of abduction and rotation, the elbow is positioned in slight flexion, and the forearm is positioned in 0 degrees of supination and pronation. If a measurement of pure glenohumeral extension is required, the scapula must be stabilized to prevent elevation and anterior tilting.
Goniometer Placement. The fulcrum is centered close to the acromion process, the proximal arm is aligned with the midaxillary line of the thorax, and the distal arm is aligned with the lateral midline of the humerus, using the lateral epicondyle of the humerus as a landmark.
Technique. The shoulder is moved passively or actively to the end range of available shoulder extension (Fig. 13-6). The clinician can take a measurement of AROM (Fig. 13-7) or PROM, or both if a comparison is to be made.
FIGURE 13-6 Passive shoulder extension.
FIGURE 13-7 Goniometric measurement of shoulder extension.
Shoulder Abduction. Although measured here with the patient positioned in supine, shoulder abduction can be measured with the patient in sitting or prone, which has the advantage of allowing free motion of the scapula.
Upper Extremity Position. The glenohumeral joint is positioned at 0 degrees of flexion and extension, and full external rotation so that the palm of the hand faces anteriorly to prevent the greater tubercle of the humerus impacting on the upper portion of the glenoid fossa or acromion process. Pure glenohumeral abduction can be measured by stabilizing the scapula to prevent its upward rotation and elevation.
Goniometer Placement. The fulcrum is centered close to the anterior aspect of the acromion process, the proximal arm is aligned so that it is parallel to the midline of the anterior aspect of the sternum, and the distal arm is aligned with the medial midline of the humerus using the medial epicondyle as a landmark. If shoulder abduction is measured with the patient in the seated position, the fulcrum is centered close to the posterior aspect of the acromion process, the proximal arm is aligned parallel to the spinous processes of the vertebral column, and the distal arm is aligned with the lateral midline of the humerus, using the lateral epicondyle as a landmark.
Technique. The shoulder is moved passively or actively to the end range of available shoulder abduction (Fig. 13-8), and a goniometric measurement is made (Fig. 13-9).
FIGURE 13-8 Passive shoulder abduction.
FIGURE 13-9 Goniometric measurement of shoulder abduction.