Purposes of joint range of motion evaluation:
1. To establish the existing range of motion available in a joint and to compare it to the normal range for that subject. The information will permit the therapist to establish a database for the patient. This information is used to develop goals and a treatment plan to increase or decrease the range of motion.
2. To aid in diagnosing and determining the patient's joint function.
Goniometry reveals joint limitations in the arc of motion but does not identify the dysfunction. It provides information regarding limitations if joint disease is suspected. Hyper-mobility or hypo-mobility of joints affects the patient's function in activities of daily living. Hyper-mobility is laxity in the joint or the structures surrounding the joint, allowing motion to exceed the normal range or a more-than-normal range of motion.
Hypo-mobility is a joint tightness or a less-than-normal range of motion.
An example of joint hypo-mobility interfering with a person's daily living activities would be an inability to perform stair climbing because of a 70°
- 80° restriction in knee flexion.
3. To re-assess the patient's status after treatment and compare it to that at the time of the initial evaluation. Goniometric measurements are used to evaluate the effectiveness of the treatment program. If the range of motion is not increasing, the treatment program may need to be changed in order to obtain effective clinical results.
4. To develop the patient's interest, motivation and enthusiasm for the treatment program. Most patients are aware of changes in joint motion and usually are motivated by these improvements to participate effectively in the treatment.
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Factors affecting range of motion:
1. Reliability:
Although experienced therapists are reliable in taking goniometric measurements, there is still some concern about the clinical reliability of goniometry. When measuring, the therapist must try to rule out as many of the factors that decrease reliability as possible. Some of the factors which improve reliability include removal of tight and restrictive clothing, duplication of positions used and re-measuring at the same time of the day.
2. Age:
Generally, the younger the subject, the greater his range of motion is. It has been found that there was a decline in range of motion in most patients between the age of 20 and 30 years, followed by a plateau until the age of 60 years, after which a decline again occurred.
3. Sex:
Many studies have been performed to determine the difference in range of motion between men and women. Overall, it has been found that women tend to have greater ranges than men but not all studies confirm that finding.
4. Joint structure:
Some persons, because of genetics or posture, normally have hyper-mobile or hypo-mobile joints. Body type can influence joint mobility, as can flexibility of the tendons and ligaments crossing the joint. Joints are structured so that motion is limited by the capsule, ligaments and tendons or by the bony configuration. Moreover, some motions are limited by soft tissue bulk of the segments. For instance, elbow flexion is usually limited by muscle bulk of the arm against the forearm. Soft tissues such as ligaments, tendons and capsules are dense; they may become tight or loose and affect the motion available at joints.
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* Muscles:
Muscles associated with the joints may become stretched or contracted; thereby affecting the joint motion. The shape of the joint surfaces is designed to allow motion in particular directions. These surfaces may be altered by such factors as posture, disease or trauma; to allow more or less motion than normal at a joint. Normally, each joint has a small amount of motion at the end of the range that is not under voluntary control. These accessory motions are not assessed during active range evaluation but are included under the term of passive measurements. Accessory motions help protect the joint structures by absorbing extrinsic forces.
When performing goniometric measurements, the examiner should consider the "end feel" of each joint when determining passive range of motion. The
“end feel”
is the sensation transmitted to the therapist’s hands at the extreme end of the passive ROM and indicates the structures that limit the joint movement. A normal end feel exists when there is full
ROM at the joint and the normal anatomy of the joint stops the movement. An abnormal end feel exists when there is either a decreased or increased joint ROM or when there is a normal ROM but structures other than the normal anatomy stop the joint movement. The end feel may be normal (physiologic) or abnormal (pathologic).
Types of motion:
1. Active range of motion:
Testing the active ROM provides limited information regarding joint motion. Assuming that the subject has complete passive ROM, an inability to actively move the segment completely through the motion must be attributed to muscle weakness. Active range grossly evaluates coordination of movement and functional ability.
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2. Passive range of motion:
It is the amount of motion possible when the examiner moves a body part with no assistance from the subject. It is usually greater than active ROM because the integrity of the soft tissue structures does not dictate the limits of movement. A passive ROM test gives the examiner information about the integrity of the joint but provides no information about the capabilities of the contractile tissues.
Instruments:
The instruments used for measuring joint range of motion are called goniometers or arthrometers. The tools, although varying in size, shape and appearance; all possess the capabilities to provide specific information regarding joint motion. The widely used universal goniometer is durable, washable and can be applied to almost all joints.
The goniometer is basically a protractor with two long arms. One arm is considered movable and the other is stationary and both are attached to the body of the protractor tension knob.
Movement terminology:
* Angular movement: It refers to movement that produces an increase or decrease in the angle between the adjacent bones. It includes: flexion, extension, abduction and adduction.
* Rotation movements: They generally occur around a longitudinal vertical axis. They include: internal (medial, inward) rotation, external
(lateral, outward) rotation, neck or trunk rotation, scapular rotation, circumduction, thumb opposition, horizontal abduction and adduction and tilting (anterior and posterior tilt of the scapula and pelvis).
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Contraindications and precautions:
Both active and passive ROM assessment techniques are contraindicated in:
1. Region of a dislocation or unhealed fracture.
2. Immediately following surgical procedures to tendons, ligaments, muscle, joint capsule or skin.
3. Presence of myositis ossificans.
Extra care is needed when performing active or passive ROM assessment where motion to the part might aggravate the condition, as in: a) Patients with hemophilia. b) Presence of an infection or inflammatory process in a joint. c) Region of marked osteoporosis. d) Region of hematoma (notably at the elbow, hip or knee). e) Hyper-mobile or subluxed joint. f) Painful conditions.
Assessment of range of motion:
1. Active range of motion:
The patient performs all active movements that normally occur at the affected joints and at the joints proximal and distal to the affected ones. The therapist observes as the patient performs each active movement one at a time; and if possible bilaterally and symmetrically.
The active ROM provides information about the patient's willingness to move, co-ordination, level of consciousness, movements that cause or increase pain, muscle strength and ability to follow instructions and perform functional activities. Active range of motion may be decreased due to restricted joint mobility, muscle weakness, pain, inability to follow instructions and / or unwillingness to move. Observation of active ROM should be followed by assessment of passive ROM.
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2. Passive range of motion:
Passive range of motion is assessed to determine the amount of movement possible at the joint. Passive ROM is usually slightly greater than active ROM due to the slight elastic stretch of tissues and in some instances due to the decreased bulk of the relaxed muscles. The therapist takes the body segments through a passive ROM to estimate each joint’s range of motion, determine the quality of the movement throughout the
ROM and the end feel to determine whether a capsular on non-capsular pattern of movement is present and note the presence of pain. The therapist repeats the passive ROM and measures and records both using a goniometer.
Methods to assess “end feel”: a) Normal (physiologic) end feels:
* Hard (bony): An abrupt, hard stop to movement when a bone contacts a bone. For example, in passive elbow extension, the olecranon process contacts the olecranon fossa.
* Soft (soft tissue opposition): When two body surfaces come together, a soft compression of tissue is felt. For example, in passive knee flexion, the posterior aspects of the calf and thigh come together.
* Firm (soft tissue stretch): A firm or springy sensation that has some give when muscle is stretched. For example, in passive ankle dorsi flexion with the knee in extension, the movement is stopped due to tension in the gastrocnemius muscle.
* Capsular stretch: A hard arrest to the movement that has some give when the joint capsule or ligaments are stretched. The feel is similar to stretching a piece of leather. For example, it occurs in passive shoulder external rotation.
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b) Abnormal (pathologic) end feels:
* An abrupt hard stop to movement, which occurs when bone contacts bone or a bony grating sensation when rough articular surfaces move past one another as in a joint that contains loose bodies, degenerative joint disease, dislocation or a fracture.
* A loose sensation indicates the presence of synovitis or soft tissue edema.
* A springy sensation or a hard arrest to movement with some give indicates muscular, capsular or ligamentous shortening. A rebound is seen or felt and indicates the presence of an internal derangement, such as a knee with a torn meniscus.
* If considerable pain is present, there is no sensation felt before the extreme of passive ROM as the patient requests the movement be stopped. This indicates pathology such as an extra articular abscess, a neoplasm, acute bursitis, joint inflammation or a fracture
* A hard sudden-stop to passive movement that is often accompanied by pain is indicative of an acute or sub-acute arthritis, presence of severe active lesion or fracture. If pain is absent, a spasm end feel indicates lesion of the central nervous system, with increased muscular tone.
Dominance:
Most researchers have found that there is essentially no difference for corresponding joints between the left and right sides of the body.
Comparative goniometry is done when a joint is involved unilaterally, while the contra-lateral limb can then be used as the standard for normal range of motion for that subject.
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Basic elements of ROM testing:
* The simple double-armed goniometer is the most desirable for general clinical use, especially for the large joints. There are small goniometers which are used for small joints, such as the finger joints.
* In an attempt to make joint measurement as accurate as possible, bony prominences are used as reference points. The stationary arm of the goniometer is lined up with two prominences and the nail head or axis of the goniometer is placed in the area of the axis of apparent motion of the joint itself.
* As a general rule, the goniometer is always applied to the lateral side of the joint, except for in measuring forearm supination.
* The instrument should be held loosely away from, or in light contact with the patient's body. When trying to maintain the position of the goniometer against the moving part, the instrument position may prohibit the patient from executing his full ROM.
* No force should be exerted on the body during placing the instrument otherwise the accuracy of placement may be affected. For example, slight pressure on the volar surface of the wrist might give 5° to 10° above true supination.
* When the limb moves anteriorly to produce flexion, the protractor is directed anteriorly in the antero-posterior plane. Conversely, when the limb moves posteriorly to produce extension, the protractor is inverted and directed posteriorly in the same plane. In other words, the protractor is always placed in the direction of the movement to be measured, except in pronation and supination.
* Measurement of each arc of motion should begin at 0° and progress towards 180°. Most joints, when are in the anatomical position, are at 0° of motion.
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* As joint motion occurs, the amount of joint motion is positively recorded in degrees. When the anatomical position cannot be attained, the degree of disability is recorded by a lack of motion equal to its magnitude.
* Measuring the unaffected side often will give the expected normal range for this particular individual.
* The mid-position is the starting position for certain measurements, as in pronation and supination, shoulder rotation, wrist flexion and extension and ankle plantar and dorsiflexion.
* An understanding of both the anatomical position and the preferred starting position is necessary in the proper orientation of the therapist to the problems of joint measuring.
* Placing the patient in good body alignment simulates the anatomical position as closely as possible. Deviation from the initial alignment should be prevented as possible during the execution of the movement to be measured. Such deviation or substitution of motion may affect results significantly
* Before starting measurement, the patient should be told clearly what to do. If necessary, the movement is demonstrated to the patient to execute as pure an anatomical motion as possible with no substitution or compensatory movements.
* For ease in measuring and to isolate best the desired motion, the joints are measured from specific starting positions rather than in the true erect anatomical position.
* Having aligned the body, the patient is instructed to swing the moving part rhythmically through the arc of motion to be measured and localize the approximate axis of rotation by inspection. If this cannot be done volitionally, move the part passively.
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* By finding the maximum degree of motion in both directions, the ROM can be calculated. For example, flexion plus extension equals full ROM and pronation plus supination equals full ROM.
* The elbow and knee are considered to be at 0° extension, since motion progresses normally in only one direction from the anatomical position.
The ROM is found by subtracting the lack of extension of the joint from the flexion obtained. For example, if flexion is 100° and extension is 20°, so ROM equals 80°.
* In joints moving in two directions from zero position, the maximum motion in both directions is added to obtain the full ROM. For example in shoulder, wrist and radio-ulnar joints; flexion and extension equals ROM.
If the return to the zero anatomical position is not possible, the two figures are subtracted.
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