Reliability of ultrasound to measure the distance between lumbar interspinous processes.

OBJECTIVES: This study aimed to determine the reliability of ultrasound to measure the distance between interspinous processes of the lumbar spine at the segmental level (i.e., L1-L2, L2-L3, L3-L4, and L4-L5). METHODS: Ten men with no history of orthopedic diseases or dysfunctions were included in this study. In total, 720 images of the lumbar spines of participants were analyzed (10 participants, 4 segments, 3 trials, 3 positions, 2 examiners). With participants in three different positions, images of each segment specifically focused on the distance between lumbar interspinous processes. Bland-Altman analysis (BAA) was used to determine intra- and inter-rater reliability. RESULTS: Intra-rater intraclass correlation coefficient (ICC) values (1, 1) were found to range from 0.840 to 0.988, whereas inter-rater ICC values (2, 1) ranged from 0.605 to 0.876. BAA results confirmed a fixed bias regarding the L4-L5 of the lumbar spine segment in the flexion position. CONCLUSIONS: Inter-rater reliability decreased throughout this study; however, results showed that using ultrasound to measure the distance between lumbar segmental interspinous processes could be applied in clinical settings to evaluate lumbar segmental mobility.

Repeated standing back extension exercise: Influence on muscle shear modulus change after lumbodorsal muscle fatigue.

BACKGROUND: In low back pain, multifidus muscle fibers reportedly exhibit increased stiffness. Low back pain was associated with lumbodorsal muscle fatigue. There is no report of using shear modulus to verify the mechanism of an immediate effect of exercise on low back pain. Here, temporary lumbodorsal muscle fatigue was created, simulating fatigue-related nonspecific low back pain. OBJECTIVE: To assess the effect of standing back extension exercise on fatigued lumbodorsal muscle based on the results of multifidus muscle elasticity measured using shear wave elastography. METHODS: Thirty-three healthy subjects were randomly divided into three groups. The subjects performed the Biering-Sorensen test as the fatigue-task of the lumbodorsal muscle before the standing back extension exercise. The fatigue-exercise group exercised five sets after completing the fatigue-task. The fatigue-non-exercise group remained standing for the same duration as the fatigue-exercise group without doing the exercise after the fatigue-task. The non-fatigue-exercise group exercised five sets of without performing the fatigue-task. As intra-group and inter-group factors, the shear modulus of the multifidus muscle was compared before and after the exercise. RESULTS: The shear modulus of the multifidus muscle after the standing back extension exercise was significantly lower in the fatigue-exercise group, and no significant decrease was observed in the fatigue-non-exercise and non-fatigue-exercise group. CONCLUSIONS: The standing back extension exercise improved the shear modulus of the fatigued multifidus muscle. Therefore, it was suggested that the change in the elasticity of fatigued muscle might lead to the prevention of low back pain caused by muscle fatigue.

Reproducibility of elastic modulus measurement of the multifidus using the shear wave elastography function of an ultrasound diagnostic device.

[Purpose] This study aimed to obtain evidence of the musculo-physiological involvement in the effect of physiotherapy on low back pain by examining the reproducibility of elasticity measurements of the multifidus muscle at different trunk angles via the shear wave elastography function of an ultrasound diagnostic device. [Participants and Methods] This study included 11 healthy adults. Measurements were conducted with participants in the prone position, and the elasticity of the superficial and deeper layers of the multifidus muscle was measured under the following 3 conditions: trunk at neutral position, trunk flexed at 40°, and trunk extended at 20°. Next, intraclass correlation coefficients (1, 1) were calculated to examine the intrarater reliability. [Results] All intraclass correlation coefficients for the superficial and deeper layers of the multifidus muscle were ≥0.85 for all 3 conditions. [Conclusion] Regardless of the trunk position, the elastic modulus measurement of inner muscles via shear wave elastography serves as an assessment of biological changes in individuals with lower back pain in response to interventions.

Change in the circulation and activity of the lower erector spinae muscles after repeated trunk extension movement.

BACKGROUND: The optimum repetition number of standing back-extension exercise (SBEE) effective for the prevention and improvement of low back pain (LBP) is unknown. OBJECTIVE: To determine the effect of physiotherapy on LBP by investigating the optimum repetition number of SBEE via optical analysis and electromyographic (EMG) examination of the multifidus muscles. METHODS: Hemodynamics and multifidus muscle activity were examined in 16 healthy adult men using near-infrared spectroscopy and surface EMG after performing repetitive SBEE. RESULTS: Oxidized hemoglobin (Oxy-Hb) levels significantly increased in the second extension phase but decreased in the third and subsequent extension phases; deoxidized hemoglobin (deOxy-Hb) levels increased in the third and subsequent extension phases. In the standing phase, no significant difference was observed; in the third and subsequent phases, Oxy-Hb levels decreased and deOxy-Hb levels increased. Muscular activity significantly decreased in the second standing phase but increased in the third and subsequent phases. No significant difference was observed in the extension phase with respect to the number of SBEE repetitions performed. In healthy individuals, hemodynamics improved up to second repetition of SBEE; subsequent repetitions may decrease hemodynamics because of increased activity of the multifidus muscles. CONCLUSIONS: In healthy individuals, hemodynamics improved up to second repetition of SBEE.

Reliability and Validity of Seated Hip Extensor Strength Measurement by Handheld Dynamometer in Older Adults.

BACKGROUND AND PURPOSE: Muscle strength measurements with the handheld dynamometer are sometimes performed according to manual muscle testing. However, measuring hip extensor muscle strength in the prone position is difficult, since the some older adults have kyphosis or flexion contracture of the lower limbs. Alternatively, there is the standing position method of manual muscle testing, which accomodates those malalignments; however, it is known that the muscle strength of the lower limb that is not measured affects the measurement result. Hence, we devised the hip extensor strength measurement in a sitting position for healthy males in previous studies. This study examined the reliability and validity of the sitting measurement by a handheld dynamometer in older adults. METHODS: Participants were 40 older adults (age [SD] = 82.4 [4.3] years). Measurements of isometric hip extensor muscle strength using a handheld dynamometer in 3 positions (sitting, standing, and prone) were conducted twice. A surface electromyogram was used to measure the activity of the gluteus maximus and the semitendinosus muscles. The reliability of muscle strength in each posture was examined with Cronbach α coefficient, intraclass correlation coefficients (ICCs1,1), and Bland-Altman analysis. The concurrent validity of muscle strength for the sitting and standing positions with reference to the prone position was examined with Spearman rank correlation and Bland-Altman analysis. Furthermore, muscle strength and muscle activity were compared between each posture. RESULTS: The Cronbach α coefficient was 0.75. For each posture, the ICC1,1 was 0.86 to 0.87, with no systematic error in the sitting and prone positions. The sitting and standing positions were significantly associated with the prone position (rs = 0.72 and 0.42), with no systematic error between the sitting and prone positions. Proportional error was demonstrated between the standing and prone positions (P < .01). There was no significant difference in muscle strength between any posture. Gluteus maximus muscle activity was significantly higher in the sitting versus standing position (P < .05). CONCLUSION: The measurement of hip extensor muscle strength in the sitting position is a reliable and valid method in older adults, which can be effective even when the prone position is not possible.

Absolute and relative reliability of lumbar interspinous process ultrasound imaging measurements.

[Purpose] The intra- and inter-examiner reliabilities of lumbar interspinous process distances measured by ultrasound imaging were examined. [Subjects and Methods] The subjects were 10 males who had no history of orthopedic diseases or dysfunctions. Ten lumbar interspinous images from 360 images captured from 10 subjects were selected. The 10 images were measured by nine examiners. The lumbar interspinous process distance measurements were performed five times by each examiner. In addition, four of the nine examiners measured the distances again after 4 days for test-retest analysis. In statistical analysis, the intraclass correlation coefficient was used to investigate relative reliability, and Bland-Altman analysis was used to investigate absolute reliability. [Results] The intraclass correlation coefficients (1, 1) for intra-examiner reliability ranged from 0.985 to 0.998. For inter-rater reliability, the intraclass correlation coefficient (2, 1) was 0.969. The intraclass correlation coefficients (1, 2) for test-retest reliability ranged from 0.991 to 0.999. The Bland-Altman analysis results indicated no systematic error. [Conclusion] The results indicate that ultrasound measurements of interspinous process distance are highly reliable even when measured only once by a single person.

Effects of movement from a postural maintenance position on lumbar hemodynamic changes.

[Purpose] To investigate the effects of movement from a postural maintenance position on lumbar hemodynamic changes, in order to prevent lower back pain and develop exercise therapy. [Subjects and Methods] Twenty-five healthy adults (mean age: 23.2 years) participated in the study. During flexion-extension exercise, the subjects moved their trunks gradually to a flexed position from an upright posture while sitting and standing, and then returned to and maintained an upright (re-upright) position. In the extension-flexion exercise, the subjects moved their trunks gradually from an upright posture to an extended position, and back while maintaining an upright (re-upright) position. Lumbar spinal muscle activity and hemodynamic changes were evaluated during both exercises. [Results] During the flexion and extension exercises, increased trunk-flexion angle caused increased muscle activity, decreased oxygenated hemoglobin in the multifidus muscle, and increased deoxygenated hemoglobin in the multifidus and lumbar erector spinae muscles. Moreover, the muscle activities were nearly the same in the re-upright and upright positions, and total hemoglobin also increased. [Conclusion] In both standing and sitting positions, holding the trunk in a flexed position causes ischemic hemodynamic changes in the multifidus muscle; however, the hyperemic response when returning the trunk to an extended position may improve circulation.

Measuring seated hip extensor strength using a handheld dynamometer: an examination of the reliability and validity of the protocol.

[Purpose] The purpose of this study was to examine the reliability and validity of measurements of hip extensor muscle strength using a handheld dynamometer (HHD) with subjects in a sitting position. In doing so, we also aimed to establish a modified method of measurement for patients with flexion contractures in the trunk and lower extremities. [Subjects and Methods] In 20 healthy males, hip extensor muscle strength was measured using a handheld dynamometer in sitting, prone, and standing positions by contracting the hip extensor muscle isometrically with the knee flexed at 90 degrees. For each position, we investigated the relative and absolute reliability and validity of the measurements, and compared muscle strength between the different positions. [Results] The reliability and validity of measurements were highest in the sitting position and higher in both the sitting and standing positions as compared with those in the prone position. [Conclusion] Our findings suggest that measurements taken in a sitting position are accurate in assessing hip extensor muscle strength and would be applicable to patients with flexion contractures in the trunk and lower extremities.

Reliability and validity of an ultrasound-based imaging method for measuring interspinous process distance in the lumbar spine using two different index points.

[Purpose] This study assessed the reliability and validity of an ultrasound-based imaging method for measuring the interspinous process distance in the lumbar spine using two different index points. [Subjects and Methods] Ten healthy males were recruited. Five physical therapy students participated in this study as examiners. The L2-L3 interspinous distance was measured from the caudal end of the L2 spinous process to the cranial end of the L3 spinous process (E-E measurement) and from the top of the L2 spinous process to the top of the L3 spinous process (T-T measurement). Intraclass correlation coefficients were calculated to estimate the relative reliability. Validity was assessed using a model resembling the living human body. [Results] The reliability study showed no difference in intra-rater reliability between the two measurements. However, the E-E measurement showed higher inter-rater reliability than the T-T measurement (Intraclass correlation coefficients: 0.914 vs. 0.725). Moreover, the E-E measurement method had good validity (Intraclass correlation coefficients: 0.999 and 95% confidence interval for minimal detectable change: 0.29 mm). [Conclusion] These results demonstrate the high reliability and validity of ultrasound-based imaging in the quantitative assessment of lumbar interspinous process distance. Of the two methods, the E-E measurement method is recommended.