Rehabilitative ultrasound imaging

Neuromuscular deficits have been linked with chronic musculoskeletal conditions. The use of ultrasound imaging (USI) to aid rehabilitation of neuromusculoskeletal disorders has been called rehabilitative ultrasound imaging (RUSI) and defined as 'a procedure used by physical therapists to evaluate muscle and related soft tissue morphology and function during exercise and physical tasks. RUSI is used to assist in the application of therapeutic interventions, providing feedback to the patient and physical therapist (Teyhen 2006). Brightness mode (b-mode) USI is the most common form used by physical therapists and will be the focus of this summary

The evaluation of lumbar multifidus muscle function via palpation: Reliability and validity of a new clinical test

Background context The lumbar multifidus muscle provides an important contribution to lumbar spine stability, and the restoration of lumbar multifidus function is a frequent goal of rehabilitation. Currently, there are no reliable and valid physical examination procedures available to assess lumbar multifidus function among patients with low back pain. Purpose To examine the inter-rater reliability and concurrent validity of the multifidus lift test (MLT) to identify lumbar multifidus dysfunction among patients with low back pain. Study design/setting A cross-sectional analysis of reliability and concurrent validity performed in a university outpatient research facility. Patient sample Thirty-two persons aged 18 to 60 years with current low back pain and a minimum modified Oswestry disability score of 20%. Study participants were excluded if they reported a history of lumbar spine surgery, lumbar radiculopathy, medical red flags, osteoporosis, or had recently been treated with spinal manipulation or trunk stabilization exercises. Outcome measures Concurrent measures of lumbar multifidus muscle function at the L4–L5 and L5–S1 levels were obtained with the MLT (index test) and real-time ultrasound imaging (reference standard). Methods The inter-rater reliability of the MLT was examined by measuring the level of agreement between two blinded examiners. Concurrent validity of the MLT was investigated by comparing clinicians' judgments with real-time ultrasound imaging measures of lumbar multifidus function. Results Inter-rater reliability of the MLT was substantial to excellent (κ=0.75 to 0.81, p≤.01) and free from errors of bias and prevalence. When performed at L4–L5 or L5–S1, the MLT demonstrated evidence of concurrent validity through its relationship with the reference standard results at L4–L5 (rbis=0.59–0.73, p≤.01). The MLT generally failed to demonstrate a relationship with the reference standard results from the L5–S1 level. Conclusions Our results provide preliminary evidence supporting the reliability and validity of the MLT to assess lumbar multifidus function at the L4–L5 spinal level. Additional research examining the measurement properties and utility of this test should be undertaken before confident implementation with patients

The effect of averaging multiple trials on measurement error during ultrasound imaging of transversus abdominis and lumbar multifidus muscles in individuals with low back pain

STUDY DESIGN: Clinical measurement, reliability study. OBJECTIVES: To investigate the improvements in precision when averaging multiple measurements of percent change in muscle thickness of the transversus abdominis (TrA) and lumbar multifidus (LM) muscles. BACKGROUND: Although the reliability of TrA and LM muscle thickness measurements using rehabilitative ultrasound imaging (RUSI) is good, measurement error is often large relative to mean muscle thickness. Additionally, percent thickness change measures incorporate measurement error from both resting and contracted conditions. METHODS: Thirty volunteers with nonspecific low back pain participated. Thickness measurements of the TrA and LM muscles were obtained using RUSI at rest and during standardized tasks. Percent thickness change was calculated with the formula (thickness contraded thickness rest/thickness rest. Standard error of measurement (SEM) quantified precision when using 1 or a mean of 2 to 6 consecutive measurements. RESULTS; Compared to when using a single measurement, SEM of both the TrA and LM decreased by nearly 25% when using a mean of 2 measures, and by 50% when using the mean of 3 measures. Little precision was gained by averaging more than 3 measurements. CONCLUSION: When using RUSI to determine percent change in TrA and LM muscle thickness, intraexaminer measurement precision appears to be optimized by using an average of 3 consecu-tive measurements

Reliability of rehabilitative ultrasound imaging of the transversus abdominis and lumbar multifidus muscles

Koppenhaver SL, Hebert JJ, Fritz JM, Parent EC, Teyhen DS, Magel JS. Reliability of rehabilitative ultrasound imaging of the transversus abdominis and lumbar multifidus muscles. Objectives: To evaluate the intraexaminer and interexaminer reliability of rehabilitative ultrasound imaging (RUSI) in obtaining thickness measurements of the transversus abdominis (TrA) and lumbar multifidus muscles at rest and during contractions. Design: Single-group repeated-measures reliability study. Setting: University and orthopedic physical therapy clinic. Participants: A volunteer sample of adults (N=30) with current nonspecific low back pain (LBP) was examined by 2 clinicians with minimal RUSI experience. Interventions: Not applicable. Main Outcome Measures: Thickness measurements of the TrA and lumbar multifidus muscles at rest and during contractions were obtained by using RUSI during 2 sessions 1 to 3 days apart. Percent thickness change was calculated as thicknesscontracted-thicknessrest/thicknessrest. Intraclass correlation coefficients (ICC) were used to estimate reliability. Results: By using the mean of 2 measures, intraexaminer reliability point estimates (ICC3,2) ranged from 0.96 to 0.99 for same-day comparisons and from 0.87 to 0.98 for between-day comparisons. Interexaminer reliability estimates (ICC2,2) ranged from 0.88 to 0.94 for within-day comparisons and from 0.80 to 0.92 for between-day comparisons. Reliability estimates comparing measurements by the 2 examiners of the same image (ICC2,2) ranged from 0.96 to 0.98. Reliability estimates were lower for percent thickness change measures than the corresponding single thickness measures for all conditions. Conclusions: RUSI thickness measurements of the TrA and lumbar multifidus muscles in patients with LBP, when based on the mean of 2 measures, are highly reliable when taken by a single examiner and adequately reliable when taken by different examiners

Association between change in abdominal and lumbar multifidus muscle thickness and clinical outcome following spinal manipulative therapy

No abstract availabl

Preliminary investigation of the mechanisms underlying the effects of manipulation: Exploration of a multivariate model including spinal stiffness, multifidus recruitment, and clinical findings

Study Design.: Prospective case series. Objective.: To examine spinal stiffness in patients with low back pain (LBP) receiving spinal manipulative therapy (SMT), evaluate associations between stiffness characteristics and clinical outcome, and explore a multivariate model of SMT mechanisms as related to effects on stiffness, lumbar multifidus (LM) recruitment, and status on a clinical prediction rule (CPR) for SMT outcomes. Summary of Background Data.: Mechanisms underlying the clinical effects of SMT are poorly understood. Many explanations have been proposed, but few studies have related potential mechanisms to clinical outcomes or considered multiple mechanisms concurrently. Methods.: Patients with LBP were treated with two SMT sessions over 1 week. CPR status was assessed at baseline. Clinical outcome was based on the Oswestry disability index (ODI). Mechanized indentation measures of spinal stiffness and ultrasonic measures of LM recruitment were taken before and after each SMT, and after 1 week. Global and terminal stiffness were calculated. Multivariate regression was used to evaluate the relationship between stiffness variables and percentage ODI improvement. Zero-order correlations among stiffness variables, LM recruitment changes, CPR status, and clinical outcome were examined. A path analysis was used to evaluate a multivariate model of SMT effects. Results.: Forty-eight patients (54% women) had complete stiffness data. Significant immediate decreases in global and terminal stiffness occurred post-SMT regardless of outcome. ODI improvement was related to greater immediate decrease in global stiffness (P = 0.025), and less initial terminal stiffness (P = 0.01). Zero-order correlations and path analysis supported a multivariate model suggesting that clinical outcome of SMT is mediated by improvements in LM recruitment and immediate decrease in global stiffness. Initial terminal stiffness and CPR status may relate to outcome though their relationship with LM recruitment. Conclusion.: The underlying mechanisms explaining the benefits of SMT appear to be multifactorial. Both spinal stiffness characteristics and LM recruitment changes appear to play a role

Criterion validity of manual assessment of spinal stiffness

Assessment of spinal stiffness is widely used by manual therapy practitioners as a part of clinical diagnosis and treatment selection. Although studies have commonly found poor reliability of such procedures, conflicting evidence suggests that assessment of spinal stiffness may help predict response to specific treatments. The current study evaluated the criterion validity of manual assessments of spinal stiffness by comparing them to indentation measurements in patients with low back pain (LBP). As part of a standard examination, an experienced clinician assessed passive accessory spinal stiffness of the L3 vertebrae using posterior to anterior (PA) force on the spinous process of L3 in 50 subjects (54% female, mean (SD) age ¼ 33.0 (12.8) years, BMI ¼ 27.0 (6.0) kg/m2) with LBP. A criterion measure of spinal stiffness was performed using mechanized indentation by a blinded second examiner. Results indicated that manual assessments were uncorrelated to criterion measures of stiffness (spearman rho ¼ 0.06, p ¼ 0.67). Similarly, sensitivity and specificity estimates of judgments of hypomobility were low (0.20 e0.45) and likelihood ratios were generally not statistically significant. Sensitivity and specificity of judgments of hypermobility were not calculated due to limited prevalence. Additional analysis found that BMI explained 32% of the variance in the criterion measure of stiffness, yet failed to improve the relationship between assessments. Additional studies should investigate whether manual assessment of stiffness relates to other clinical and biomechanical constructs, such as symptom reproduction, angular rotation, quality of motion, or end feel

Association between changes in abdominal and lumbar multifidus muscle thickness and clinical improvement after spinal manipulation

OBJECTIVE: To examine the relation between improved disability and changes in abdominal and lumbar multifidus (LM) thickness using ultrasound imaging following spinal manipulative therapy (SMT) in patients with low back pain (LBP). BACKGROUND: Although there is a growing body of literature demonstrating physiologic effects following the application of SMT, few studies have attempted to correlate these changes with clinically relevant outcomes. METHODS: Eighty-one participants with LBP underwent 2 thrust SMT treatments and 3 assessment sessions within 1 week. Transversus abdominis (TrA), internal oblique (10), and LM muscle thickness was assessed during each session, using ultrasound imaging of the muscles at rest and during submaximal contractions. The Modified Oswestry Disability Index was used to quantify participants' improvement in LBP-related disability. Stepwise hierarchical multiple linear regression and repeated-measures analysis of variance were performed to examine the multivariate relationship between change in muscle thickness and clinical improvement over time. RESULTS: After controlling for the effects of age, sex, and body mass index, change in contracted LM muscle thickness was predictive of improved disability at 1 week (P = .02). As expected, larger increases in contracted LM muscle thickness at 1 week were associated with larger improvements in LBP-related disability. Contrary to our hypothesis, significant decreases in both contracted TrA and 10 muscle thickness were observed immediately following SMT; but these changes were transient and unrelated to whether participants experienced clinical improvements. CONCLUSION: These findings provide evidence that clinical improvement following SMT is associated with increased thickening of the LM muscle during a submaximal task

Association between history and physical examination factors and change in lumbar multifidus muscle thickness after spinal manipulation in patients with low back pain

Understanding the clinical characteristics of patients with low back pain (LBP) who display improved lumbar multifidus (LM) muscle function after spinal manipulative therapy (SMT) may provide insight into a potentially synergistic interaction between SMT and exercise. Therefore, the purpose of this study was to identify the baseline historical and physical examination factors associated with increased contracted LM muscle thickness one week after SMT. Eighty-one participants with LBP underwent a baseline physical examination and ultrasound imaging assessment of the LM muscle during submaximal contraction before and one week after SMT. The relationship between baseline examination variables and 1-week change in contracted LM thickness was assessed using correlation analysis and hierarchical multiple linear regression. Four variables best predicted the magnitude of increases in contracted LM muscle thickness after SMT. When combined, these variables suggest that patients with LBP, (1) that are fairly acute, (2) have at least a moderately good prognosis without focal and irritable symptoms, and (3) exhibit signs of spinal instability, may be the best candidates for a combined SMT and lumbar stabilization exercise (LSE) treatment approach