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Assessing Flexibility

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Objectives

• Differentiate between static and dynamic flexibility• Identify factors affecting flexibility• Identify methods for assessing flexibility• Understand reliability and validity of flexibility

assessments• Understand general guidelines for flexibility testing• Understand how to assess flexibility of older adults

Basics of Flexibility

• Flexibility and joint stability are highly dependent on– joint structure and– strength and number of ligaments and muscles

spanning the joint.

Definitions and Nature of Flexibility

• Flexibility is the ability of a joint, or series of joints, to move through a full range of motion (ROM) without injury.

• Static flexibility is a measure of total ROM at the joint, limited by the extensibility of the musculotendinous unit.

• Dynamic flexibility is a measure of the rate of torque or resistance developed during stretching throughout the ROM.

(continued)

Definitions and Nature of Flexibility (continued)

• ROM is highly specific to the joint and depends on morphological factors such as the following:– joint geometry – joint capsule– ligaments– tendons– muscles spanning the joint

(continued)

Definitions and Nature of Flexibility (continued)

• Relative contribution of soft tissues to total resistance encountered by the joint during movement:– Joint capsule—47% – Muscle and its fascia—41%– Tendons and ligaments—10%– Skin—2%

(continued)

Definitions and Nature of Flexibility (continued)

• Tension in the muscle–tendon unit affects both static (ROM) and dynamic flexibility (stiffness or resistance to movement):– viscoelastic properties – elastic deformation – viscous deformation – stress relaxation

Factors Affecting Flexibility

• Hypertrophied muscles and excess subcutaneous fat may impede flexibility.

• Static flexibility progressively decreases as muscle stiffness increases with aging.

• Females are generally more flexible than males, regardless of age; may be joint-specific.

• Lack of physical activity is a major cause of inflexibility.• Active warm-up combined with static stretching is more

effective than static stretching alone.

Assessment of Flexibility

• Difficult and expensive to assess dynamic flexibility• Static flexibility assessed in field and clinical settings by

direct or indirect measurement of ROM

General Guidelines for Flexibility Testing

• Have client perform general warm-up followed by static stretching prior to the test.

• Avoid fast, jerky movements, and stretching to the point of pain.

• Administer three trials of each test item.• Compare client’s best score to norms to obtain a

flexibility rating for each test item.• Use the test results to identify joints and muscle groups

in need of improvement.

Direct Methods of Measuring Static Flexibility

• Goniometer: protractor-like device with two steel or plastic arms that measure the joint angle at the extremes of the ROM

• Flexometer: consists of a weighted 360° dial and weighted pointer

• Inclinometer: measures the angle between the long axis of the moving segment and the line of gravity

Goniometry

1. Place the center of the instrument so it coincides with the fulcrum, or axis of rotation, of the joint.

2. Align the arms of the goniometer with bony landmarks along the longitudinal axis of each moving body segment.

3. Measure the ROM as the difference between the joint angles (degrees) at the extremes of the movement.

4. Follow standard procedures by joint.

Figure 10.1a

Figure 10.1b

Table 10.2

Table 10.2 (continued)Table 10.2

Flexometer Test Procedures

1. Strap the instrument to the body segment.

2. Lock the dial at 0° at one extreme of the ROM.

3. After the client executes the movement, lock the pointer at the other extreme of the ROM.

4. The degree of arc through which the movement takes place is read directly from the dial.

Figure 10.2a

Figure 10.2b

Inclinometer Test Procedures

• Easier to use than the flexometer and universal goniometer

• Held by hand on the moving body segment during the measurement

• Alignment with specific bony landmarks not required• American Medical Association recommends the

double-inclinometer technique to measure spinal mobility.

Figure 10.3a

Figure 10.3b

Validity and Reliability of Direct Measures

• Highly dependent on the joint being measured and technician skill

• High agreement between ROM measured by radiographs and universal goniometers for the hip and knee joints

• No difference between radiography and the double-inclinometer technique for assessing spinal ROM of patients with low back pain

• Inclinometer reliably measures ROM at most joints

(continued)

Validity and Reliability of Direct Measures (continued)

• Intra- and intertester reliability of goniometric measurements affected by identification of axis of rotation and palpating bony landmarks

• For inclinometer:– Intertester reliability is variable and joint specific.– Intrarater reliabilities of flexibility during hip

adduction and for ROM measurements of the lumbar spine and lordosis generally exceed 0.90.

(continued)

Validity and Reliability of Direct Measures (continued)

• Modified sit-and-reach test to evaluate the static flexibility of the lower back and hamstring muscles:

– Moderately related to criterion measures of hamstring flexibility for adults and poorly related to low back flexibility of adults

– No better than that of the standard sit-and-reach test for assessing flexibility of the low back and hamstring muscle groups

(continued)

Validity and Reliability of Direct Measures (continued)

• Back-saver sit-and-reach test to evaluate the static flexibility of the lower back and hamstring muscles:

– Validity of this test is similar to that of the standard sit-and-reach test for assessing hamstring flexibility of men and women.

Indirect Methods of Measuring Static Flexibility

• Sit-and-reach test to evaluate the static flexibility of the lower back and hamstring muscles

– provides an indirect, linear measurement of the ROM.

– is moderately related to hamstring flexibility, but poorly related to low back flexibility.

– has poor criterion-related validity and is unrelated to self-reported low back pain.

Standard Sit-and-Reach Test

• Client sits on the floor with knees extended and the soles of feet against the box edge.

• Client keeps knees fully extended, arms evenly stretched, and hands parallel with the palms down (fingertips may overlap).

• Client slowly reaches forward as far as possible along the top of the box and holds this position for two seconds.

• Client’s score is the most distant point along the top of the box that the fingertips contact.

Tips for Standard Sit-and-Reach Test

• Have client warm up prior to test.• Advise your client that lowering the head and exhaling

during the stretch maximizes the distance reached.• If the client’s knees are flexed, motion is jerky or

bouncing, or fingertips do not maintain contact with the slider, do not count that score.

• Administer two trials and record the maximum score to the nearest 0.5 cm.

• Use box with zero point at 26 cm.• Interpret using gender-specific results.

Table 10.4

V Sit-and-Reach Test

• Secure a yardstick to the floor by placing tape (12 in. long) at a right angle to the 15-inch mark on the yardstick.

• Client sits on floor, straddling the yardstick with knees extended, heels of feet on 15-inch mark and 1 foot apart.

• Client reaches forward slowly, as far as possible, along the yardstick while keeping the hands parallel.

• Client holds position about two seconds.• The score (in centimeters or inches) is the farthest

point on the yardstick contacted by the fingertips.

Tips for V Sit-and-Reach Test

• Don’t have client lock knees in extended position at start.

• Make certain that the knees do not flex and that the client avoids leading with one hand.

• Interpret the score using gender-specific normative values.

Table 10.5

Modified Sit-and-Reach Test

• Client sits on the floor with buttocks, shoulders, and head in contact with the wall.

• Client extends the knees and places the soles of the feet against the sides of box.

• Place a yardstick on top of the box with the zero end toward the client.

• Client reaches forward with one hand on top of the other while keeping the head and shoulders in contact with the wall.

(continued)

Modified Sit-and-Reach Test (continued)

• Yardstick is positioned so that it touches the fingertips; this establishes the zero point for each client.

• As you firmly hold the yardstick in place, client reaches forward slowly, sliding the fingers along the top of the yardstick.

• The score (in inches) is the most distant point on the yardstick contacted by the fingertips.

Tips for Modified Sit-and-Reach Test

• Use this test for those with long arms and short legs.• Don’t have client lock knees in extended position at

start.• Make certain that the knees do not flex and that the

client avoids leading with one hand.• Have client hold stretch for two seconds.• Record the higher of two measures.• Avoid fast, jerky movements.• Interpret the score using gender-specific norms.

Figure 10.4a

Figure 10.4b

Table 10.6

Back-Saver Sit-and-Reach Test

• Client places the sole of the foot of the extended (tested) leg against the edge of the sit-and-reach box.

• Client places the foot of the untested leg flat on the floor 2 to 3 inches to the side of the extended (tested) knee.

• Remainder of instructions are the same as for the standard sit-and-reach test.

• Determine client’s flexibility score for each leg.

Figure 10.5

Modified Back-Saver Sit-and-Reach Test

• Client performs a single-leg sit-and-reach on a 12-inch bench.

• Client places the untested leg on the floor with the knee flexed at a 90° angle.

• Align the sole of the foot of the tested leg with the 50-cm mark on the meter rule.

• Follow instructions for the standard sit-and-reach test to determine your client’s hamstring flexibility for each leg.

Tips for Modified Back-Saver Sit-and-Reach Test

• Have client warm up prior to test.• Be sure zero point of meter stick or tape measure is

pointing toward client.• Secure the meter stick or tape measure to the table.• Advise your client that lowering the head and exhaling

during the stretch maximizes the distance reached.• If the client’s test-leg knee is flexed, motion is jerky or

bouncing, or fingertips do not remain aligned, do not count that score.

• Administer two trials and record the maximum score to the nearest 0.5 cm.

Figure 10.6

Skin Distraction Test

• Place a 0 cm mark on the midline of the lumbar spine at the intersection of a horizontal line connecting the left and right posterior superior iliac spines while the client stands erect.

• Place a second mark 15 cm superior to the 0 cm mark.

• Instruct the client to bend forward at the waist as far as possible.

• Measure the new distance (cm) between the two marks.

• Record the score as new distance minus 15 cm.

Figure 10.7a

Figure 10.7b

Lumbar Stability Tests

• Use these 3 tests to evaluate the balance in the isometric endurance capabilities of back muscles in healthy individuals:

– Trunk extension– Trunk flexion– Side bridge

Trunk Extension

• Client lies prone with the lower body secured to the test bed at 3 places and with the upper body extended over the edge of the bed (bed is 10 inches from floor).

• Client holds arms across chest, hands resting on opposite shoulders.

• Client assumes and maintains horizontal position above the floor for as long as possible.

• Record time (in seconds) client maintains the horizontal position; trial ends when upper body contacts the floor.

Trunk Flexors

• Client sits on a test bench with a moveable back support set at a 60° angle.

• Client flexes the knees and hips to 90° and folds the arms across the chest.

• Use toe straps to secure client’s feet to the test bench.• Record time (in seconds) client maintains this body

position after you lower or remove the back support. • Stop stopwatch when client’s trunk falls below the 60°

angle.

Side Bridge

• Have client assume a side-lying position on a mat, legs extended.

• Have client place top foot in front of the lower foot for support.

• Instruct client to lift hips off mat while supporting the body in a straight line on one elbow and the feet for as long as possible.

• Keep the uninvolved arm across the chest.• End the test when hips return to the mat.• Use a stopwatch to record elapsed time (in seconds).• Administer test for both right and left sides of the body.

Flexibility Testing of Older Adults

• Chair sit-and-reach test:– Position folding chair against a wall.– Client sits on front edge of the seat.– Client extends test leg in front of the hip, heel on floor, ankle

dorsiflexed ~90°, knee extended.– Sole of other foot is flat on the floor about 6 to 12 inches to side

of the body’s midline.– With hands overlapped (palms down), client bends forward at

hip, keeping spine straight and head in normal alignment with spine.

– Client tries to touch toes of test leg, holding position for two seconds.

– Administer two practice trials followed by two test trials.

(continued)

Flexibility Testing of Older Adults (continued)

• Scoring chair sit-and-reach test:– Place ruler parallel to the lower leg; the zero point is

the middle of the big toe (medial aspect) at the end of the shoe.

– Reaches short of toes are recorded as minus scores; reaches beyond toes are recorded as plus scores.

– Record best score to the nearest 0.5 inch. – Interpret score through normative values.

(continued)

Figure 10.8

Table 10.8

Flexibility Testing of Older Adults (continued)

• Back scratch test:– Client reaches, with preferred hand (palm down and

fingers extended), over the shoulder and down the back.

– Client simultaneously reaches around and up the middle of the back with the other hand (palm up and fingers extended).

– Allow the client to choose the best, or preferred, hand through trial and error.

– Administer 2 practice trials followed by 2 test trials.

(continued)

Flexibility Testing of Older Adults (continued)

• Scoring back scratch test:– Use ruler to measure overlap (plus score) or gap

(minus score) between middle fingers of each hand.– If fingers just touch each other, record a zero.– Record best score to the nearest 0.5 inch. – Compare this value to the gender-specific norms.

Figure 10.9

Table 10.9