Chapter 10

1. Chapter 10 Assessing Flexibility

2. Basics of Flexibility • Flexibility is the ability of a joint, or series of joints, to move through a full range of motion (ROM) without injury. • Flexibility and joint stability are highly dependent on • joint structure and • strength and number of ligaments and muscles spanning the joint. • 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. (Although dynamic flexibility accounts for 44% to 66% of the variance in static flexibility)

3. 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

4. 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% • The joint structure determines the planes of motion and may limit the ROM at a given joint. Triaxial joints (e.g., ball-and-socket joints of the hip and shoulder) afford a greater degree of movement in more directions than nonaxial, uniaxial or biaxial joints (see table 10., p 266).

5. 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 - The tension within the muscle–tendon unit affects both static flexibility (ROM) and dynamic flexibility (stiffness or resistance to movement). The tension within this unit is attributed to the viscoelastic properties of connective tissues, as well as to the degree of muscular contraction resulting from the stretch reflex. Because tissues of the body exhibit both elastic and viscous properties, they are called “viscoelastic”. • elastic deformation - The deformation that occurs as force is applied and removed is called “elastic” deformation. The elastic deformation of the muscle–tendon unit during stretching is proportional to the load or tension applied. • viscous deformation - The deformation that occurs after force application or removal is called “viscous” deformation • stress relaxation - When the muscle and tendon are stretched and held at a fixed length (e.g., during static stretching), the tension within the unit, or tensile stress, decreases over time.

6. 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. The greater flexibility of women is usually attributed to gender differences in pelvic structure and hormones that may affect connective tissue laxity. ROM appears to be joint and motion specific, males have greater ROM in hip extension and spinal flexion and extension in the thoracolumbar region • Lack of physical activity is a major cause of inflexibility. • Active warm-up combined with static stretching is more effective than static stretching alone. (when you administer flexibility (ROM) tests, make certain that your clients warm up and statically stretch the muscle groups before you measure them, and administer multiple trials for each test item.)

7. Assessment of Flexibility • Dynamic flexibility tests measure the increase in resistance during muscle elongation; several studies have shown that less stiff muscles are more effective in using the elastic energy during movements involving the stretch–shortening cycle However, dynamic testing is difficult and expensive to assess • Static flexibility assessed in field and clinical settings by direct or indirect measurement of ROM. To assess static flexibility directly, measure the amount of joint rotation in degrees using a goniometer, flexometer, or inclinometer. To assess flexibility indirectly ( as in low back / hamstring flexibility) you can use various forms of sit and reach tests and skin distraction tests

8. 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.

9. Direct Methods of Measuring Static Flexibility (see photos in text pp. 268-272) • 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

10. Goniometry • Place the center of the instrument so it coincides with the fulcrum, or axis of rotation, of the joint. • Align the arms of the goniometer with bony landmarks along the longitudinal axis of each moving body segment. • Measure the ROM as the difference between the joint angles (degrees) at the extremes of the movement. • Follow standard procedures by joint. (see Table 10.2, pp. 269-270, and slides that follow) See Photo Examples next slides

11. Figure 10.1a

12. Figure 10.1b

13. Table 10.2

14. Table 10.2 (continued) Table 10.2

15. Flexometer Test Procedures • Strap the instrument to the body segment. • Lock the dial at 0° at one extreme of the ROM. • After the client executes the movement, lock the pointer at the other extreme of the ROM. • The degree of arc through which the movement takes place is read directly from the dial. See photo examples next slides

16. Figure 10.2a

17. Figure 10.2b

18. Inclinometer Test Procedures • Easier to use than the flexometer and universal goniometer • The inclinometer is another type of gravity-dependent goniometer (see figure 10.3). To use this device, hold it on the distal end of the body segment. The inclinometer measures the angle between the long axis of the moving segment and the line of gravity. • 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. See photo examples next slides

19. Figure 10.3a

20. Figure 10.3b

21. Validity and Reliability of Direct Measures • Highly dependent on the joint being measured and technician skill • High agreement between ROM measured by radiographs ( Radiography is considered to be the best reference method for establishing validity of goniometric measurements.) 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

22. Validity and Reliability of Direct Measures (continued) • Intra-and inter-tester reliability of goniometric measurements affected by identification of axis of rotation and palpating bony landmarks • For inclinometer: • Inter-tester reliability is variable and joint specific. Studies have reported reliability coefficients ranging from 0.48 for lumbar extension to 0.96 for subtalar joint position. • Intra-rater reliabilities of flexibility during hip adduction and for ROM measurements of the lumbar spine and lordosis generally exceed 0.90. • In order to obtain accurate and reliable ROM measurements, you need a thorough knowledge of anatomy and of standardized testing procedures, and training / practice to develop measurement techniques.

23. Validity and Reliability of Indirect Measures • Modified sit-and-reach test to evaluate the static flexibility of the lower back and hamstring muscles: • These tests are moderately related to hamstring flexibility (r = 0.39 to 0.89) • The sit-and-reach test has poor criterion-related validity and is unrelated to self-reported low back pain. • Researchers concluded that standard fitness test batteries should include measures of lumbar ROM instead of the sit-and-reach test to assess low back fitness. • Lumbar ROM in the sagittal plane can be measured directly with an inclinometer (double-inclinometer technique, see figure 10.3) or indirectly with the skin distraction test • Although research affirms that the sit-and-reach test does not validly measure low back flexibility, it may still be used to provide an indirect measure of hamstring length, thus it may be used to assess these changes

24. 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.

25. 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.

26. 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. (see next slide)

27. Table 10.4

28. 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.

29. 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. (see next slide)

30. Table 10.5

31. Modified Sit-and-Reach Test (see photos in sequential slides) • 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.

32. 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.

33. 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.

34. Figure 10.4a

35. Figure 10.4b

36. Table 10.6

37. Back-Saver Sit-and-Reach Test (see photo in sequential slide) • 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.

38. Figure 10.5

39. Modified Back-Saver Sit-and-Reach Test (see photo in sequential slide) • 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.

40. 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.

41. Figure 10.6

42. Skin Distraction Test (see photos in sequential slides) • 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.

43. Figure 10.7a

44. Figure 10.7b

45. Lumbar Stability Tests • Lumbar instability increases the risk of developing low back pain. The primary muscle groups responsible for stabilizing the lumbar spine are the trunk extensors (erector spinae), trunk flexors (rectus abdominis and abdominal oblique muscles), and lateral flexors (quadratuslumborum). • 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

46. 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.

47. 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.

48. 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.

49. 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.

50. Flexibility Testing of Older Adults (see photo in sequential slide) • Many older individuals have difficulty performing sit-and-reach tests because functional limitations (e.g., low back pain and poor ROM) prevent them from getting down to and up from the floor. • The chair sit-and-reach test is similar to the back-saver protocol (see figure 10.6) in that it tests only one leg, thereby reducing stress on the spine and lower back.