Changes in Shear Modulus of the Lumbar Multifidus Muscle During Different Body Positions.

Multifidus function is important for active stabilization of the spine, but it can be compromised in patients with chronic low back pain and other spine pathologies. Force production and strength of back muscles are often evaluated using isometric or isokinetic tests, which lack the ability to quantify multifidi contribution independent of the erector spinae and adjacent hip musculature. The objective of this study is to evaluate localized force production capability in multifidus muscle using ultrasound shear wave elastography (SWE) in healthy individuals. Three different body positions were considered: lying prone, sitting up, and sitting up with the right arm lifted. These positions were chosen to progressively increase multifidus contraction and to minimize body motion during measurements. Shear modulus was measured at the superficial and deeper layers of the multifidus. Repeatability and possible sources of error of the shear modulus measurements were analyzed. Multifidus shear modulus (median (interquartile range)) increased from prone, i.e., 16.15 (6.69) kPa, to sitting up, i.e., 27.28 (15.72) kPa, to sitting up with the right arm lifted position, i.e., 45.02 (25.27) kPa. Multifidi shear modulus in the deeper layer of the multifidi was lower than the superficial layer, suggesting lower muscle contraction. Intraclass correlation coefficients (ICCs) for evaluation of shear modulus by muscle layer were found to be excellent (ICC = 0.76-0.80). Results suggest that the proposed protocol could quantify local changes in spinal muscle function in healthy adults; further research in patients with spine pathology is warranted.

Association Between Self-Reported Kinesiophobia and Single-Leg Hop for Distance in Patients With ACL Reconstruction: A Systematic Review.

CONTEXT: Psychological readiness is a significant factor in determining successful return to sport (RTS) and physical activities after anterior cruciate ligament (ACL) reconstruction. Knowing the influence of kinesiophobia on physical tests that are used to guide RTS, such as the single-leg hop for distance (SLHD), would contribute to advancing clinical practice. OBJECTIVE: To investigate the association between kinesiophobia and SLHD performance in patients after ACL reconstruction. DATA SOURCES: A comprehensive search strategy entailed surveying 6 databases for relevant articles published from January 2009 to March 2021. STUDY SELECTION: Articles published in English that were a minimum of level 3 evidence describing kinesiophobia, as measured by the Tampa Scale for Kinesiophobia, and related to SLHD performance in patients after ACL reconstruction. STUDY DESIGN: Systematic review. LEVEL OF EVIDENCE: Level 3. DATA EXTRACTION: Study characteristics, sample population demographics, instrument(s), or approach(s) used to assess kinesiophobia and SLHD performance, and corresponding results. RESULTS: A total of 152 potential studies were identified, 106 studies underwent screening, 40 were reviewed in full, and 7 studies were included. Meta-analysis could not be performed because of differences in experimental design among studies and instances of missing outcome data. Currently, moderate evidence indicates patients with ACL reconstruction that exhibit less kinesiophobia perform better on the SLHD test. CONCLUSION: The outcomes of this review propose that sports health practitioners consider the influence of kinesiophobia on SLHD performance as a criterion for RTS and physical activities in patients after ACL reconstruction. Higher quality studies are necessary to establish the extent of association between these variables.

Predictive Factors of the Effectiveness of Caudal Epidural Steroid Injections in Managing Patients With Chronic Low Back Pain and Radiculopathy.

STUDY DESIGN: Retrospective clinical outcome analysis. OBJECTIVE: To evaluate and determine whether demographic, comorbid factors, or physical examination findings may predict the outcome of caudal epidural steroid injections in managing patients with chronic low back pain and radiculopathy SUMMARY OF BACKGROUND DATA:: The caudal epidural approach is commonly utilized with patients who are on anticoagulation or who have had prior lumbar surgery to treat L5 or S1 radiculopathies. METHODS: A retrospective review of 136 patients undergoing an initial caudal epidural steroid injection for radiculopathy from January 1, 2006 to August 30, 2013. The patients were assessed before their injections for their pain levels: visual analog scale, presence of lumbar paraspinal and sciatic notch sensitivity, pain with provocative maneuvers, motor weakness, and sensory loss. The patients were then reassessed following their injection for their visual analog scale pain levels, percentage improvement, and duration of pain relief. RESULTS: Stepwise regression was used to determine whether demographic, comorbid factors, or physical examination signs were predictive of percentage improvement or length of relief following an injection. Among these variables, duration of symptoms was found to be negatively significantly related with a P-value of 0.032 for percentage of improvement. For each week of the duration of symptoms, the percentage of improvement decreased by 0.07%. Regarding physical examination findings, presence of pain with lumbar extension was negatively and significantly related to length of relief duration with a P-value of 0.0124. The mean length of relief duration is 38.37 weeks for individuals without painful lumbar extension and 14.68 weeks for individuals with painful lumbar extension CONCLUSIONS:: The mean length of relief following a caudal injection is reduced by 62% in patients who exhibit pain with lumbar extension.

Changes in lumbar disk morphology associated with prolonged sitting assessed by magnetic resonance imaging.

OBJECTIVE: To determine what if any changes occur to the lumbar disks in the spine after prolonged sitting with and without intermittent breaks during a 4-hour period. DESIGN: A prospective observational study. SETTING: An academic outpatient clinic. METHODS: The measurement of lumbar disk changes was performed with 12 subjects after an analysis of a mid sagittal lumbar magnetic resonance image, which measured lumbar disk height and disk diameter. Scanning and analysis were done over a 2-day period: day 1 at the start of the work day and 4 hours later after continuous sitting; at the start of work day 2 and after four hours after a change in position and stretching protocol every 15 minutes. RESULTS: For this study, we first evaluated each level of the lumbar spine for any changes after prolonged sitting for 4 hours over the 2 days. Multiple comparisons bias was eliminated by a Bonferroni correction to limit the overall experiment-wise error rate to .05. The comparison was conducted by using a paired t-test when the normality condition was satisfied and by using a Wilcoxon signed rank test when normality was not satisfied. To test for normality, a Shapiro-Wilk test was used. We found that, for disk height, L4-5 was significantly decreased at the end of the sitting for day 1 but not for day 2. There were no significant height changes for the other lumbar disks. In addition, for disk diameter, there were no significant differences present for any of the disks. CONCLUSIONS: Analysis of the data shows that the greatest change in disk height is at the L4-5 level after prolonged sitting without intermittent breaks. The other levels did not show a significant change in their height. The findings also showed that the L4-5 height changes were not significant with brief positional changes every 15 minutes. Fewer changes in disk height may correlate with an improvement in low back pain and disability.