Exploring the relationship between trunk muscles and lower limb injuries in Australian badminton players.

Due to its dynamic nature, lower limb injuries are common in badminton. Overuse injuries of the knee, including tendon related conditions, are the most common. During jumping and landing, force transference and dissipation through the trunk is required, with the trunk muscles playing a vital role. However, the relationship between knee pain and the ability to voluntarily contract the trunk muscles has not yet been explored in badminton players. A cross-sectional study of Australian badminton players was therefore conducted. Players performed a single leg decline squat to identify those with knee pain. Ultrasound imaging was used to image and measure the size of the multifidus and quadratus lumborum, and the ability to contract the abdominal and multifidus muscles. Voluntary contraction of the trunk muscles was conducted with the subjects lying down. Independent samples T-Tests were performed to test for between group differences. Badminton players with knee pain had larger quadratus lumborum muscles and demonstrated a greater change in muscle thickness from the rested to contracted state. While we cannot comment on causation or direction, over co-contraction of trunk muscles has been shown in other studies to be associated with increased ground reaction forces on landing. Motor control training has been successfully used in other conditions to modify trunk muscle recruitment patterns and may therefore potentially represent a useful approach for badminton players.

The effects of a 12-week combined motor control exercise and isolated lumbar extension intervention on lumbar multifidus muscle stiffness in individuals with chronic low back pain.

Introduction: Exercise therapy is the primary endorsed form of conservative treatment for chronic low back pain (LBP). However, there is still conflicting evidence on which exercise intervention is best. While motor control exercise can lead to morphological and functional improvements of lumbar multifidus muscle in individuals with chronic LBP, the effects of exercise prescription on multifidus stiffness assessed via shear wave elastography are still unknown. The primary aim of this study is to determine the effects of a combined motor control and isolated lumbar extension (MC + ILEX) intervention on lumbar multifidus muscle stiffness. Methods: A total of 25 participants aged 18 to 65 were recruited from local orthopedic clinics and the university community with moderate to severe non-specific chronic LBP. Participants performed a 12-week MC + ILEX intervention program. Stiffness of the lumbar multifidus muscle (primary outcome) at L4 and L5 was obtained at baseline, 6-week, and 12-week using shear wave elastography. Changes in stiffness ratio (e.g., ratio of lumbar multifidus muscle stiffness from rest to contracted) were also assessed at both time points. Pre to post-intervention changes in lumbar multifidus muscle stiffness were assessed using a one-way repeated measure ANOVA. Results: Following the 12-week intervention, there were no statistically significant changes in lumbar multifidus muscle stiffness at rest on the right side at L4 (p = 0.628) and the left side at L4 and L5 (p = 0.093, p = 0.203), but a statistically significant decrease was observed on the right side at L5 (p = 0.036). There was no change in lumbar multifidus muscle stiffness ratio. Conclusion: This study provides preliminary evidence to suggest that a 12-week MC + ILEX intervention had minimal effect on lumbar multifidus muscle stiffness in individuals with chronic LBP. Further investigations are needed to confirm our findings and clarify the relationship between muscle stiffness and functional outcomes.

Perspective: Timely diagnosis and repair of intraoperative thoracic/lumbar cerebrospinal fluid (CSF) leaks.

Background: Our review of 12 articles for this perspective showed the frequency of intraoperative thoracic and/or lumbar CSF fistulas/dural tears (DT) ranged from 2.6% - 8% for primary surgical procedures. Delayed postoperative CSF leak/DT were also diagnosed in 0.83% (17/2052 patients) to 14.3% (2/14 patients) of patients undergoing thoracic and/or lumbar procedures. Further, the rate of recurrent postoperative CSF leaks/DT varied from 13.3% (2/15 patients) to 33.3% (4/12 patients). Methods: Intraoperative, postoperative delayed, and recurrent postoperative traumatic postsurgical thorac CSF leaks/DT can be limited by performing initially sufficient operative decompressions and/or decompressions/fusions (i.e., utilizing adequate open exposures vs. inadequate minimally invasive (MI) approaches). The incidence of CSF leaks/DT can be further reduced by spine surgeons' utilization of operating microscopes, and their avoiding routine attempts at total synovial cyst excision and/or complete resection of hypertrophied/ossified yellow ligament in the presence of significant dural adhesions. Results: Multiple CSF leak/CT repair techniques included; using interrupted, non-resorbable sutures for direct dural repairs (i.e. 7-0 Gore-Tex sutures where the suture is larger than the needle thus plugging needle holes), and adding where needed muscle patch grafts, microfibrillar collagen, the rotation of Multifidus muscle pedicle flaps, fibrin sealants (FS)/fibrin glues (FG), lumbar drains (LD), and/or lumbo-peritoneal (LP) shunts. Conclusion: Intraoperative, postopertive delayed, and/or recurrent postoperative thorac and/or lumbar traumatic surgical CSF leaks can be reduced by choosing to initially perform the appropriately extensive open operative decompressions and/or decompresssions/fusions. It is critical to use an operating microscope, non-resorbable interrupted sutures, and where necessary, muscle patch grafts, microfibrillar collagen, the rotation of Multifidus Muscle Pedicle Flaps, FS/FG, LD, and/or LP shunts.

Comparison of clinical and radiographic outcomes in unilateral transforaminal lumbar interbody fusion: a retrospective analysis of three surgical approaches.

PURPOSE: The primary objective of this study is to evaluate and compare the clinical and radiographic outcomes of the combined spinous process-splitting approach with a Wiltse (SPSW) approach, the combined conventional approach with a Wiltse (CW) approach, and the conventional open (CO) approach in unilateral transforaminal lumbar interbody fusion (TLIF). METHODS: The clinical outcomes were assessed, and intraoperative data and complications were collected. Numeric Rating Scale (NRS) scores for low back pain and leg pain, the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) scores for evaluating functions of the lumbar spine and health-related quality of life, and the modified MacNab standard for assessing satisfaction were analyzed. Radiographic outcomes included disc space height, segmental lordosis, interbody fusion assessment, and the rate of muscle atrophy of the multifidus and the erector spinae muscles. RESULTS: Among the three groups, the SPSW group exhibited the shortest operation and drain retention time, lowest intraoperative blood loss, and minimal postoperative blood loss. Notably, the SPSW group displayed the highest level of social life function based on the JOABPEQ, and the highest level of patient satisfaction according to the modified MacNab Criteria, along with the lowest rate of muscle atrophy. CONCLUSION: All the SPSW, CW, and CO approach TLIF procedures achieved overall satisfactory effects of decompression and fusion for lumbar degenerative diseases. The SPSW approach procedure appears to be associated with the smallest surgical trauma and highest satisfaction because of reducing iatrogenic injury of the paraspinal muscles.

[Radiographic parameters and influencing factors of paraspinal muscle degeneration in healthy people].

Objective: To measure the paraspinal muscle parameters, explore the characteristics of paraspinal muscles, and investigate the influence factors of paraspinal muscle degeneration in healthy people. Methods: Eighty-two healthy Chinese people were prospectively recruited between February 2020 and November 2020, including 36 males and 46 females. The age ranged from 21 to 75 years, with a mean of 48.0 years. The height ranged from 150 to 183 cm, with a mean of 165.6 cm. The body mass ranged from 43 to 100 kg, with a mean of 65.4 kg. The body mass index (BMI) ranged from 16.7 to 32.4 kg/m 2, with a mean of 23.7 kg/m 2. Parameters of the paraspinal muscles (multifidus muscle, erector spinae muscle, and psoas major muscle) at L 3, L 4, and L 5 levels were measured by MRI, including the relative total cross-sectional area (rtCSA), relative fatty cross-sectional area (rfCSA), relative signal intensity (rSI), and fatty infiltration (FI). The differences of paraspinal muscle parameters at different genders and different measurement levels were compared; Pearson or Spearman correlation analysis was used to explore the relationship between paraspinal muscle parameters and age, height, body mass, BMI. Results: From L 3 to L 5 level, the rtCSA and rfCSA of multifidus muscle and psoas major muscle as well as the rfCSA of erector spinae muscle increased, while rtCSA of erector spinae muscle decreased. The FI and rSI of paraspinal muscles increased gradually. The parameters of paraspinal muscles at L 4 and L 5 levels were significantly different from those at L 3 levels ( P<0.05). There were significant differences in rtCSA and rfCSA of multifidus muscle, rtCSA, FI, and rSI of erector spinae muscle as well as rtCSA, rfCSA, and FI of psoas major muscle between L 4 and L 5 levels ( P<0.05). Compared with males, the rfCSA and FI of multifidus muscle, FI of erector spinae muscle, and FI of psoas major muscle were significantly higher in females, while the rtCSA of psoas major muscle was significantly lower ( P<0.05). Age was significantly negatively correlated with rtCSA of paraspinal muscles ( P<0.05), but significantly positively correlated with FI of paraspinal muscles, rfCSA and rSI of multifidus and erector spinae muscles ( P<0.05). Height was significantly negatively correlated with rfCSA and FI of paraspinal muscles ( P<0.05). Conclusion: The degree of paraspinal muscle degeneration increases gradually along the spine axis from head to tail. Paraspinal muscle degeneration is related to age, height, and gender. The relationship between the body mass, BMI and paraspinal muscle degeneration needs further study.

The feasibility and efficacy of pedicle fixation by the Wiltse approach in the thoracic spine.

Study design: Retrospective Cohort Study. Objectives: To explore the feasibility and assess the efficacy of pedicle fixation with the Wiltse approach in the thoracic spine. Summary of background data: The current application of Wiltse approach is mainly practiced in the lumbar and thoracolumbar spines. Its application in the thoracic spine, however, has received little attention, especially in cases that requires only pedicel screw fixation without spinal decompression. Methods: The study analyzed the clinical records of consecutive patients with thoracic diseases who underwent pedicle fixation with either Wiltse or the conventional transmuscular approach (Wiltse group: 60 cases; Transmuscular group: 48 cases). Perioperative parameters, Visual Analogue Scale (VAS) scores, accuracy of pedicle screw placement, dead space between the muscles, Magnetic Resonance Imaging (MRI) appearance, electrophysiological changes in the multifidus muscle were compared between the two groups. Results: Compared with the transmuscular group, the Wiltse group was significantly better in blood loss and postoperative VAS scores. No difference was observed in incision length, operation time, and hospital stay. The dead space between the muscle cross-sectional region in the transmuscular group was 315 ± 53 mm2, and no dead space was found in the Wiltse group. On MRI images, the multifidus cross-sectional area (CSA) in the Wiltse group between the preoperative period and the last follow-up reduced by only 10.1%, while transmuscular group showed 46.1% CSA reduction. Electrophysiologically, the median frequency slope of the transmuscular group grew by 47.8% with average amplitude reduced by 16.4% between the preoperative period and 12-month postoperative. Conclusion: The Wiltse approach for pedicle fixation in the thoracic spine is a feasible and effective treatment, with fewer traumas and reliable clinical results. In particular, the Wiltse approach reduces postoperative dead space between the muscles and causes less atrophy in the multifidus muscle.

Cervical Multifidus Stiffness Assessment in Individuals with and without Unilateral Chronic Neck Pain: An Inter-Examiner Reliability Study.

This study aimed to evaluate the inter-examiner reliability of shear wave elastography (SWE) for measuring cervical multifidus (CM) muscle stiffness in asymptomatic controls and patients with chronic neck pain. A longitudinal observational study was conducted to assess the diagnostic accuracy of a procedure. SWE images, following a detailed procedure previously tested, were acquired by two examiners (one novice and one experienced) to calculate the shear wave speed (SWS) and Young's modulus. The painful side was examined for the experimental cases while the side examined in the control group was selected randomly. Data analyses calculated the intra-class correlation coefficients (ICCs), absolute errors between examiners, standard errors of measurement, and minimal detectable changes. A total of 125 participants were analyzed (n = 54 controls and n = 71 cases). The Young's modulus and SWS measurements obtained by both examiners were comparable within the asymptomatic group (both, p > 0.05) and the chronic neck pain group (both, p > 0.05). Nonetheless, a notable distinction was observed in the absolute error between examiners for shear wave speed measurements among patients with neck pain, where a significant difference was registered (p = 0.045), pointing to a sensitivity in measurement consistency affected by the presence of chronic neck pain. ICCs demonstrated moderate-to-good reliability across both groups, with ICC values for asymptomatic individuals reported as >0.8. Among the chronic neck pain patients, ICC values were slightly lower (>0.780). The study revealed moderate-to-good consistency, highlighting the practicality and generalizability of SWE.

Increased water content in multifidus muscles of young adults with chronic nonspecific low back pain detected by dual-energy CT and MRI.

OBJECTIVES: To demonstrate the feasibility of better diagnosing young adults with chronic nonspecific low back pain (CNLBP) by measuring water content in paraspinal muscles using water-muscle decomposition technique in dual-energy CT (DECT) and T2-mapping in MRI. METHODS: This prospective cross-sectional study included 110 young individuals (56 with CNLBP at age of 25.7 ± 2.0 years and 54 of asymptomatic at age of 25.1 ± 1.9 years) who underwent both MRI and DECT on the spine. T2 values on T2 mapping in MRI and water density (WD) value on water(muscle) images in DECT were generated at the L1-L4 levels for erector spinae muscle and L2-L5 for multifidus muscle. Pain duration time, Oswestry Disability Index (ODI), Visual Analogue Scale (VAS) were recorded for CNLBP patients. Difference of T2 value and WD between the two patient groups, and correlations between T2 value and WD, and T2 value and WD with clinical indicators were analyzed. RESULTS: Compared with asymptomatic participants, the mean WD of multifidus muscle at L4-L5 and mean T2 values of multifidus muscle at L5 were significantly higher in CNLBP patients (all P < 0.05). T2 values had moderate to strong positive correlations (r = 0.34-0.60, all P < 0.05) with DECT WD in CNLBP patients and healthy volunteers. There was a weak correlation between VAS and WD in L5-level multifidus muscle (r = 0.29, P < 0.05). CONCLUSIONS: The T2 values in MRI and WD in DECT are higher in multifidus muscles of lower vertebra levels for young CNLBP patients, and there exists positive correlation between WD and T2 values, providing useful information for diagnosing CNLBP.

Georg Schmorl Prize of the German Spine Society (DWG) 2023: the influence of sarcopenia and paraspinal muscle composition on patient-reported outcomes: a prospective investigation of lumbar spinal fusion patients with 12-month follow-up.

PURPOSE: This study aimed to investigate the impact of sarcopenia and lumbar paraspinal muscle composition (PMC) on patient-reported outcomes (PROs) after lumbar fusion surgery with 12-month follow-up (12 M-FU). METHODS: A prospective investigation of patients undergoing elective lumbar fusion was conducted. Preoperative MRI-based evaluation of the cross-sectional area (CSA), the functional CSA (fCSA), and the fat infiltration(FI) of the posterior paraspinal muscles (PPM) and the psoas muscle at level L3 was performed. Sarcopenia was defined by the psoas muscle index (PMI) at L3 (CSAPsoas [cm2]/(patients' height [m])2). PROs included Oswestry Disability Index (ODI), 12-item Short Form Healthy Survey with Physical (PCS-12) and Mental Component Scores (MCS-12) and Numerical Rating Scale back and leg (NRS-L) pain before surgery and 12 months postoperatively. Univariate and multivariable regression determined associations among sarcopenia, PMC and PROs. RESULTS: 135 patients (52.6% female, 62.1 years, BMI 29.1 kg/m2) were analyzed. The univariate analysis demonstrated that a higher FI (PPM) was associated with worse ODI outcomes at 12 M-FU in males. Sarcopenia (PMI) and higher FI (PPM) were associated with worse ODI and MCS-12 at 12 M-FU in females. Sarcopenia and higher FI of the PPM are associated with worse PCS-12 and more leg pain in females. In the multivariable analysis, a higher preoperative FI of the PPM (ß = 0.442; p = 0.012) and lower FI of the psoas (ß = -0.439; p = 0.029) were associated with a worse ODI at 12 M-FU after adjusting for covariates. CONCLUSIONS: Preoperative FI of the psoas and the PPM are associated with worse ODI outcomes one year after lumbar fusion. Sarcopenia is associated with worse ODI, PCS-12 and NRS-L in females, but not males. Considering sex differences, PMI and FI of the PPM might be used to counsel patients on their expectations for health-related quality of life after lumbar fusion.

Pedicled multifidus muscle flaps to treat dural tears due to penetrating spinal stab wounds: Two case reports and a literature review.

Background: Penetrating spinal injuries occasionally lead to dural tears (DT) and cerebrospinal fluid (CSF) leaks that risk both infectious and neurological complications. Here, we reviewed two cases and the literature regarding the safety/efficacy and limitations of repairing traumatic DT utilizing pedicled multifidus muscle flaps. Case Description: Two males, ages 73 and 50, presented with Brown-Sequard syndromes and DT/CSF fistulas attributed to knife-induced spinal injuries at the D3-D4 and D11-D12 levels. Intraoperatively, DT was repaired utilizing pedicle multifidus muscle flaps. Postoperatively, both patients demonstrated partial recovery of neurological function along with no residual symptoms/signs of DT/CSF fistulas. Conclusion: Penetrating traumatic spinal injuries may result in DT/CSF fistulas that can be adequately repaired utilizing pedicle multifidus muscle flaps.

Quantitative Evaluation of the Lumbar Multifidus Muscle by Shear Wave Dispersion in Healthy Adults: A Preliminary Study.

OBJECTIVES: To investigate the application value of shear wave dispersion (SWD) in healthy adults with the lumbar multifidus muscle (LMM), to determine the range of normal reference values, and to analyze the influences of factors on the parameter. METHODS: Ninety-five healthy volunteers participated in the study, from whom 2-dimensional, shear wave elastography (SWE), and SWD images of the bilateral LMM were acquired in three positions (prone, standing, and anterior flexion). Subcutaneous fat thickness (SFH), SWE velocity, and SWD slope were measured accordingly for analyses. RESULTS: The mean SWD slope of the bilateral LMM in the prone position was as follows: left: 14.8 ± 3.1 (m/second)/kHz (female) and 13.0 ± 2.5 (m/second)/kHz (male); right: 14.8 ± 3.7 (m/second)/kHz (female) and 14.2 ± 3.4 (m/second)/kHz (male). In the prone position, there was a weak negative correlation between the bilateral LMM SWD slope of activity level 2 and level 1 (ß = -1.5 (2 versus 1, left), -1.9 (2 versus 1, right), all P < .05), and between the left SWD slope of activity level 3 and level 1 (ß = -2.3 [3 versus 1, left], P < .05). The correlation between SWE velocity and SWD slope value changed with the position: there was a weak positive correlation in the prone position (r = 0.3 [left], 0.37 [right], both P < .05), and a moderate positive correlation in the standing and anterior flexed positions (r = 0.49-0.74, both P < .001). SFH was moderately negatively correlated with bilateral SWD slope values in the anterior flexion (left: r = -0.4, P = .01; right: r = -0.7, P < .01). CONCLUSIONS: SWD imaging can be used as an adjunct tool to aid in the assessment of viscosity in LMM. Further, activity level, and position are influencing factors that should be considered in clinical practice.

The difference in multifidus muscle morphology and motor control in non-specific low back pain with clinical lumbar instability and healthy subjects: A case-control study.

BACKGROUND: Low back pain (LBP) with clinical lumbar instability (CLI) is considered a subgroup of back pain. Poor core stability function and/or lack of motor controls are thought to play a role in inappropriate inter-segmental movements and pain. There is no study investigating the changes in the lumbar multifidus muscle (LMM) morphology and motor control in this subgroup of patients. OBJECTIVE: To assess motor control components and morphological changes of LMM in the patients suffering from chronic nonspecific low back pain (CNSLBP) with CLI. DESIGN: Observational case-control study. METHODS: Thirty-two patients suffering from (CNSLBP) with CLI and 32 healthy individuals were included. The muscle force element of lumbar motor control was assessed by using (the active straight-leg raise test, leg lowering test, and Trendelenburg test). Ultrasonography was used to assess changes in the LMM morphology. RESULTS: There was a significant decrease in motor control (p = 0.0001), an increase in LMM fatty infiltration (p = 0.002), and a decrease in the thickness of LMM in patients suffering from CNSLBP during contraction (p = 0.006), during rest (p = 0.018). The cross-section area of the LMM showed no statistically significant differences during rest on the right and left sides (p = 0.827, 0.220 respectively) and contraction (p = 0.160, 0.278 respectively) between patients and healthy subjects. CONCLUSION: Motor control and the morphology of LMM in patients with CNSLBP with CLI may provide insight into the mechanisms of underlying pain and their effect on muscle function and structure.

Pain quality patterns in delayed onset muscle soreness of the lower back suggest sensitization of fascia rather than muscle afferents: a secondary analysis study.

Delayed onset muscle soreness (DOMS) of the lower back is considered a surrogate for acute low back pain (aLBP) in experimental studies. Of note, it is often unquestioningly assumed to be muscle pain. To date, there has not been a study analyzing lumbar DOMS in terms of its pain origin, which was the aim of this study. Sixteen healthy individuals (L-DOMS) were enrolled for the present study and matched to participants from a previous study (n = 16, L-PAIN) who had undergone selective electrical stimulation of the thoracolumbar fascia and the multifidus muscle. DOMS was induced in the lower back of the L-DOMS group using eccentric trunk extensions performed until exhaustion. On subsequent days, pain on palpation (100-mm analogue scale), pressure pain threshold (PPT), and the Pain Sensation Scale (SES) were used to examine the sensory characteristics of DOMS. Pain on palpation showed a significant increase 24 and 48 h after eccentric training, whereas PPT was not affected (p > 0.05). Factor analysis of L-DOMS and L-PAIN sensory descriptors (SES) yielded a stable three-factor solution distinguishing superficial thermal ("heat pain ") from superficial mechanical pain ("sharp pain") and "deep pain." "Heat pain " and "deep pain" in L-DOMS were almost identical to sensory descriptors from electrical stimulation of fascial tissue (L-PAIN, all p > 0.679) but significantly different from muscle pain (all p < 0.029). The differences in sensory description patterns as well as in PPT and self-reported DOMS for palpation pain scores suggest that DOMS has a fascial rather than a muscular origin.

Elucidating the Correlation between Bone Mineral Density and Multifidus Muscle Characteristics: A Cross-Modal Study with Dual-Energy X-ray Absorptiometry and Spinal Computed Tomography Texture Analysis.

BACKGROUND: Recent research underscores the clinical relevance of muscle conditions such as sarcopenia and their links to bone mineral density (BMD), yet notable gaps persist in the understanding of their interconnections. Our study addresses this by introducing a novel approach to decipher the correlation between BMD and the texture of the multifidus muscle, utilizing spinal computed tomography (CT) and dual-energy X-ray absorptiometry (DXA) to evaluate muscle texture, BMD, and bone mineral content (BMC) at the total lumbar vertebra and total hip. METHODS: Our single-institution study examined 395 cases collected from 6 May 2012 to 30 November 2021. Each patient underwent a spinal CT scan and a DXA scan within a one-month interval. BMD and BMC at the total lumbar vertebra and total hip were measured. The texture features of the multifidus muscle from the axial cuts of T12 to S1 vertebrae were assessed via gray-level co-occurrence matrices. CT texture analysis values at angles of 45 + 45 and 90 degrees were calculated and correlated with BMD and BMC. A regression model was then constructed to predict BMD values, and the precision of these correlations was evaluated using mean square error (MSE) analysis. RESULTS: Total lumbar BMC showed a correlation of 0.583-0.721 (MSE 1.568-1.842) and lumbar BMD of 0.632-0.756 (MSE 0.068-0.097). Total hip BMC had a correlation of 0.556-0.690 (MSE 0.448-0.495), while hip BMD ranged from 0.585 to 0.746 (MSE 0.072-0.092). CONCLUSIONS: The analysis of spinal CT texture alongside BMD and BMC measures provides a new approach to understanding the relationship between bone and muscle health. The strong correlations expected from our research affirm the importance of integrating bone and muscle measures in the prevention, diagnosis, and management of conditions such as sarcopenia and osteoporosis.

The effect of fatty infiltration, revision surgery, and sex on lumbar multifidus passive mechanical properties.

Purpose: Previous research has demonstrated increased stiffness in the multifidus muscle compared to other paraspinal muscles at the fiber bundle level. We aimed to compare single fiber and fiber bundle passive mechanical properties of multifidus muscle: (1) in 40 patients undergoing primary versus revision surgery and (2) in muscle with mild versus severe fatty infiltration. Methods: The degree of muscle fatty infiltration was graded using the patients' spine magnetic resonance images. Average single fiber and fiber bundle passive mechanical properties across three tests were compared between primary (N = 30) and revision (N = 10) surgery status, between mild and severe fatty infiltration levels, between sexes, and with age from passive stress-strain tests of excised multifidus muscle intraoperative biopsies. Results: At the single fiber level, elastic modulus was unaffected by degree of fatty infiltration or surgery status. Female sex (p = 0.001) and younger age (p = 0.04) were associated with lower multifidus fiber elastic modulus. At the fiber bundle level, which includes connective tissue around fibers, severe fatty infiltration (p = 0.01) and younger age (p = 0.06) were associated with lower elastic modulus. Primary surgery also demonstrated a moderate, but non-significant effect for lower elastic modulus (p = 0.10). Conclusions: Our results demonstrate that female sex is the primary driver for reduced single fiber elastic modulus of the multifidus, while severity of fatty infiltration is the primary driver for reduced elastic modulus at the level of the fiber bundle in individuals with lumbar spine pathology.

Magnetic Resonance Imaging Evaluation of Multifidus Muscle in Patients with Low Back Pain after Microlumbar Discectomy Surgery.

Cross-sectional area (CSA) and signal intensity ratio (SIR) of the multifidus muscle (MFM) on magnetic resonance imaging (MRI) was used to evaluate the extent of injury and atrophy of the MFM in patients with negative treatment outcomes following microlumbar discectomy (MLD). Negative treatment outcome was determined by pain score improvement of <50% compared to baseline. Patients in groups 1, 2, and 3 were evaluated at <4 weeks, 4-24 weeks, and >24 weeks postoperatively, respectively. The associations between the follow-up, surgery time and the changes in the MFM were evaluated. A total of 79 patients were included, with 22, 27, and 30 subjects in groups 1, 2, and 3, respectively. The MFM SIR of the ipsilateral side had significantly decreased in groups 2 (p = 0.001) and 3 (p < 0.001). The ipsilateral MFM CSA significantly decreased postoperatively in groups 2 (p = 0.04) and 3 (p = 0.006). The postoperative MRI scans found significant MFM changes on the ipsilateral side in patients with negative treatment outcomes regarding pain intensity following MLD. As the interval to the postoperative MRI scan increased, the changes in CSA of the MFM and change in T2 SIR of the MFM showed a tendency to increase.

Prolotherapy at Multifidus Muscle versus Mechanical Needling and Sterile Water Injection in Lumbar Spinal Stenosis.

Objective: This observational study aimed to compare ultrasound-guided (USG) prolotherapy with 5% dextrose in water (D5W) in the multifidus muscle to USG mechanical needling and sterile water injections for the treatment of lumbar spinal stenosis (LSS). Patients and Methods: The data was extracted from the medical records of ageing patients with LSS who received USG D5W in the multifidus muscle or USG mechanical needling and sterile water injections for the treatment of LSS by the first author. Low back pain or axial pain and leg pain or radicular pain were assessed by the visual analogue scale, and gait ability with walking distance were obtained at six different time points. Results: Among the 211 older people who were diagnosed with LSS, 104 got USG mechanical needling and sterile water injections over the course of four weeks, while the other 107 got D5W at the multifidus muscles in a single session. Chronic low back pain, radiating pain, and the ability to walk all got much better at 1 and 3 months after the intervention, compared to VAS measures taken at the start. Patients who underwent mechanical needling with injections of sterile water performed consistently and significantly better than those who received prolotherapy in the multifidus muscles on all measures at 1, 3, and 6 months. Conclusion: After receiving USG mechanical needling and sterile water, LSS patients reported significant improvements in low back pain, radicular pain, and ability to walk for at least 6 months. Prolotherapy with D5W in the multifidus muscle has a moderate effect for only three months.

Fatty infiltration of the multifidus muscle independently increases osteoporotic vertebral compression fracture risk.

BACKGROUND: Vertebral compression fractures decrease daily life activities and increase economic and social burdens. Aging decreases bone mineral density (BMD), which increases the incidence of osteoporotic vertebral compression fractures (OVCFs). However, factors other than BMD can affect OVCFs. Sarcopenia has been a noticeable factor in the aging health problem. Sarcopenia, which involves a decrease in the quality of the back muscles, influences OVCFs. Therefore, this study aimed to evaluate the influence of the quality of the multifidus muscle on OVCFs. METHODS: We retrospectively studied patients aged 60 years and older who underwent concomitant lumbar MRI and BMD in the university hospital database, with no history of structurally affecting the lumbar spine. We first divided the recruited people into a control group and a fracture group according to the presence or absence of OVCFs, and further divided the fracture group into an osteoporosis BMD group and an osteopenia BMD group based on the BMD T-score of -2.5. Using images of lumbar spine MRI, the cross-sectional area and percentage of muscle fiber (PMF) of the multifidus muscle were obtained. RESULTS: We included 120 patients who had visited the university hospital, with 45 participants in the control group and 75 in the fracture group (osteopenia BMD: 41, osteoporosis BMD: 34). Age, BMD, and the psoas index significantly differed between the control and fracture groups. The mean cross-sectional area (CSA) of multifidus muscles measured at L4-5 and L5-S1, respectively, did not differ among the control, P-BMD, and O-BMD groups. On the other hand, the PMF measured at L4-5 and L5-S1 showed a significant difference among the three groups, and the value of the fracture group was lower than that of the control group. Logistic regression analysis showed that the PMF value, not the CSA, of the multifidus muscle at L4-5 and L5-S1 affected the risk of OVCFs, with and without adjusting for other significant factors. CONCLUSIONS: High percentage of fatty infiltration of the multifidus muscle increases the spinal fracture risk. Therefore, preserving the quality of the spinal muscle and bone density is essential for preventing OVCFs.

Clinical outcomes of transforaminal lumbar interbody fusion using a modified posterior spinous process-splitting approach for lumbar degenerative or isthmic spondylolisthesis: a prospective cohort study.

In the conventional posterior approach to the lumbar spine for transforaminal lumbar interbody fusion (TLIF), the paravertebral muscles are stripped from the spinous process. The authors developed a novel surgical procedure in which TLIF was performed via a modified spinous process-splitting (SPS) approach that enabled the preservation of the attachment of the paravertebral muscles to the spinous process. The SPS TLIF group comprised 52 patients with lumbar degenerative or isthmic spondylolisthesis who underwent surgery using a modified SPS TLIF technique, whereas the control group comprised 54 patients who underwent conventional TLIF. Compared with the control group, the SPS TLIF group had a significantly shorter operation time, smaller intra- and postoperative blood loss volumes, and shorter hospital stay and time to ambulation (p < 0.05). The SPS TLIF group had a lower mean visual analog scale score for back pain than the control group on both postoperative day 3 and at 2 years postoperatively (p < 0.05). Follow-up MRI showed changes in the paravertebral muscles in 46 of 54 patients (85%) in the control group and 5 of 52 patients (10%) in the SPS TLIF group (p < 0.001). This novel technique may be a useful alternative to the conventional posterior approach for TLIF.

Ultrasonography of the multifidus muscle in student circus artists with and without low back pain: a cross-sectional study.

BACKGROUND: Degenerative structural changes and functional deficits of the lumbar multifidus (LM) muscle were observed in athletes with low back pain. While spinal injuries are common in circus artists, there is no information on LM characteristics in this population. The aims of this study were to investigate LM morphology and function and explore the relationship between LM characteristics and low back pain in male and female circus artists. METHODS: 31 college circus students were recruited. Participants completed an online survey to acquire demographic data and low back pain history. Body composition was measured using multi-frequency bio-impedance analysis. Ultrasound examinations at the fifth lumbar vertebrae in prone and standing positions were performed to assess LM cross-sectional area, echo-intensity, thickness. Independent and dependent t-test assessed the difference between sex and side, respectively. The relationships between measures were assessed with Pearson's correlations. The LM characteristics' difference between artists with and without low back pain (group binary variable) was assessed with Analysis of covariance using lean body mass, height and % body fat as continuous covariates. RESULTS: Males had significantly larger LM cross-sectional area, lower echo-intensity and greater thickness change from rest to contracted than females. LM cross-sectional area asymmetry in prone was greater in artists reporting low back pain in the previous 4-weeks (p = 0.029) and 3-months (p = 0.009). LM measures were correlated with lean body mass, height, and weight (r = 0.40-0.77, p ≤ 0.05). CONCLUSION: This study provided novel insights into LM characteristics in circus artists. Greater LM asymmetry was observed in artists with a history of low back pain. In accordance with previous studies in athletes, LM morphology and function were highly correlated with body composition measurements.