Is muscle activation diverse in females with isolated patellofemoral osteoarthritis contrasted with age-matched healthy controls during stair descent task?

Background: Patellofemoral osteoarthritis (PF OA) is exceptionally predominant and limiting. However, little is known about the risk factors that contribute to its onset and progression. Purpose: The aim of this study was to decide if women with PF OA descend stairs using different muscular activation strategies compared to similarly aged healthy controls. Methods: Thirty-one women with isolated PF OA and 11 similarly aged healthy women took part in this study. The activation onset and duration of PF OA in vastus medialis oblique (VMO), vastus lateralis (VL), gluteus medius (GM), transversus abdominis (TrA), and multifidus muscles were evaluated during the stair descent task using surface electromyography (EMG). Results: There was a non-significant difference between women with PF OA and healthy controls regarding all tested variables, except for the GM activation onset that was significantly delayed in women with PF OA, with the p-value of 0.011. Conclusion: The causes of PF OA differ and might not always be due to a lack of quadriceps strength or VMO activation deficiency, and prospective longitudinal studies are required to confirm this assumption.

Fatty Infiltration of Multifidus Muscles: An Easily Overlooked Risk Factor for the Severity of Osteoporotic Vertebral Fractures.

OBJECTIVES: Osteoporotic vertebral fractures (OVFs) are a critical public health concern requiring urgent attention, and severe OVFs impose substantial health and economic burdens on patients and society. Analysis of the risk factors for severe OVF is imperative to actively prevent the occurrence of this degenerative disorder. This study aimed to investigate the risk factors associated with the severity of OVF, with a specific focus on changes in the paraspinal muscles. METHODS: A total of 281 patients with a first-time single-level acute OVF between January 2016 and January 2023 were enrolled in the study. Clinical and radiological data were collected and analyzed. The cross-sectional area (CSA) and degree of fatty infiltration (FI) of the paraspinal muscles, including the multifidus muscles (MFMs), erector spinae muscles (ESMs), and psoas major muscles (PSMs), were measured by magnetic resonance imaging (MRI) of the L4/5 intervertebral discs. According to the classification system of osteoporotic fractures (OF classification) and recommended treatment plan, OVFs were divided into a low-grade OF group and a high-grade OF group. Univariate and multivariate logistic regression analyse s were performed to identify risk factors associated with the severity of OVF. RESULTS: Ninety-eight patients were included in the low-grade OF group, and 183 patients were included in the high-grade OF group. Univariate analysis revealed a significantly higher incidence of a high degree of FI of MFMs (OR = 1.71, p = 0.002) and ESMs (OR = 1.56, p = 0.021) in the high-grade OF group. Further multivariate logistic regression analysis demonstrated that a high degree of FI of the MFMs (OR = 1.71, p = 0.002) is an independent risk factor for the severity of OVF. CONCLUSION: A high degree of FI of the MFMs was identified as an independent risk factor for the severity of OVF. Decreasing the degree of FI in the MFMs might lower the incidence of the severity of OVF, potentially reducing the necessity for surgical intervention in OVF patients.

Diaphragmatic Activation Correlated with Lumbar Multifidus Muscles and Thoracolumbar Fascia by B-Mode and M-Mode Ultrasonography in Subjects with and without Non-Specific Low Back Pain: A Pilot Study.

Background and Objectives: The diaphragm, the lumbar multifidus muscles, and the thoracolumbar fascia (TLF) execute an important role in the stability of the lumbar spine and their morphology has been modified in subjects with non-specific low back pain (NS-LBP). While it is true that three structures correlate anatomically, the possible functional correlation between them has not been investigated previously in healthy subjects nor in subjects with NS-LBP. The aim of the present study was to examine this functional nexus by means of a comparison based on ultrasonographic parameters of the diaphragm, the lumbar multifidus muscles, and the TLF in subjects with and without NS-LBP. Materials and Methods: A sample of 54 (23 NS-LBP and 31 healthy) subjects were included in the study. The thickness and diaphragmatic excursion at tidal volume (TV) and force volume (FV), the lumbar multifidus muscles thickness at contraction and at rest, and the TLF thickness were evaluated using rehabilitative ultrasound imaging (RUSI) by B-mode and M-mode ultrasonography. The diaphragm thickening capacity was also calculated by thickening fraction (TF) at tidal volume and force volume. Results: There were no significant differences recorded between the activation of the diaphragm and the activation of the lumbar multifidus muscles and TLF for each variable, within both groups. However, there were significant differences recorded between both groups in diaphragm thickness and diaphragm thickening capacity at tidal volume and force volume. Conclusions: Diaphragmatic activation had no functional correlation with the activation of lumbar multifidus muscles and TLF for both groups. Nevertheless, subjects with NS-LBP showed a reduced diaphragm thickness and a lower diaphragm thickening capacity at tidal volume and force volume, compared to healthy subjects.

Electroacupuncture alleviates multifidus muscle injury by modulating mitochondrial function and Ca2+ uptake.

Multifidus muscles maintain the stability of the lumbar spine and play a crucial role in the pathogenesis of nonspecific lower back pain. Previous studies have shown that electroacupuncture (EA) can relieve the symptoms of low back pain and reduce injury to the lumbar multifidus muscles. In this study, a rat model of lumbar multifidus muscle injury was established by 0.05% bupivacaine injection and subsequently treated with EA at bilateral "Weizhong" (BL40) acupoints. Disruption of the function and structure of multifidus muscles, increased cytosolic Ca2+ in multifidus myocytes, and reduced mitochondrial fission and ATP production were observed in the model group. Additionally, increased expression of the mitochondrial calcium uniporter (MCU) promoted mitochondrial reuptake of Ca2+ , reversing the excessive increase in cytoplasmic Ca2+ . However, the excessive increase in MCU not only aggravated the increased cytoplasmic Ca2+ but also decreased the expression of the mitochondrial division proteins dynamin-related protein 1 (Drp1) and mitochondrial fission factor (MFF). EA inhibited the overexpression of MCU, promoted mitochondrial reuptake of Ca2+ , and reversed cytosolic Ca2+ overload. Furthermore, EA regulated the expression of the mitochondrial fission proteins Drp1 and MFF and promoted the production of ATP, helping the recovery of mitochondrial function after multifidus injury. Therefore, EA can protect against bupivacaine-induced mitochondrial dysfunction, possibly by attenuating MCU overexpression in the inner mitochondrial membrane and reducing Ca2+ overloading in muscle cells, thereby protecting mitochondrial function and maintaining the normal energy demand of muscle cells.

Characteristics of paraspinal muscle degeneration in degenerative diseases of the lumbar spine at different ages.

OBJECTIVE: To analyze the relationship between gender, age, and the degree of lumbar degenerative disease. METHODS: 290 patients with Lumbar spinal stenosis and sciatica were analyzed. Sixty patients without sciatica were collected in the control group. Patient demography including age, gender, body mass index (BMI), serum calcium, and triglyceride level was acquired. The cross-sectional area (CSA) and percentage of fat infiltration area (Intermuscular adipose tissue (IMat%) of paraspinal muscles at the L4-5 level were measured using MRI imaging. The patients were divided into five age groups: A (18-30 years old), B (31-40 years old), C (41-50 years old), D (51-60 years old), and E (> 60 years old). Analysis of variance (ANOVA) and LSD was used to analyze differences among subgroups. Student's t-test was used to compare MCSA and fat CSA in the two groups. P < 0.05 was statistically significant. RESULTS: The paraspinal muscle CSA (MCSA) was significantly smaller in women (P < 0.05). Older age was associated with less MCSA and greater fatty infiltration in erector spinae and multifidus (MF) muscle (P < 0.05). Serum calcium and BMI were positively correlated with CSA of erector spinae muscle (P < 0.05), but not with muscle fat infiltration (P > 0.05). Although there was no significant difference in MCSA between the two groups, the fat infiltration (IMat%) in the disease group was significantly higher than in the control group (p < 0.05). CONCLUSION: Lumbar degenerative diseases caused the degeneration of the paravertebral muscles, which mainly resulted in increased intramuscular fat infiltration, rather than changes in the overall MCSA.

Lumbar Multifidus Muscle Morphology Changes in Patient with Different Degrees of Lumbar Disc Herniation: An Ultrasonographic Study.

Background and Objective: Previous studies demonstrated that the prevalence of lumbar disc herniation (LDH) is relatively high. This investigation aimed to evaluate the size of lumbar multifidus (LM) muscle in patients with different degrees of LDH compared to healthy group, during rest and contraction, using ultrasonography. Materials and Methods: In this non-experimental, analytic, and case control study, ultrasound imaging was used to assess cross-sectional area (CSA) and thickness of the LM muscle in 15 healthy subjects and 60 patients with different stages of LDH (bulging group = 15, protrusion group = 15, extrusion group = 15, sequestration group = 15). Measurements were taken bilaterally at the L4-L5 level, during rest and contraction and results were compared between groups. Results: There was a significant difference between healthy subjects and the extrusion and sequestration groups during rest and contraction for LM muscle CSA and thickness (p = 0.001), as LM muscle CSA and thickness were significantly smaller in extrusion and sequestration patient groups compared to healthy subjects. LM atrophy was greater in patients with extrusion and sequestration groups than in patients with bulging and protrusion, both at rest and during contraction. Significant correlations were also observed between functional disability and intensity of pain with LM CSA and thickness measurements. Conclusions: Patients with extrusion and sequestration LDH had smaller LM muscle at rest and during contraction compared to healthy subjects. Larger LDH lesions were associated with decreased LM muscle size. Patient with more pain, disability, and extrusion and sequestration LDH had greater LM size changes. LM muscle size was not correlated with symptom duration. Further investigation with greater sample size is warranted.

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.

Multifidus Muscle Changes After Biportal Endoscopic Spinal Surgery: Magnetic Resonance Imaging Evaluation.

OBJECTIVE: We used magnetic resonance imaging (MRI) to assess the radiological status of the multifidus muscles (MFMs) after biportal endoscopic spinal surgery (BESS) and evaluated the extent of MFM injury and atrophy. METHODS: A total of 88 patients who had met the inclusion and exclusion criteria were enrolled in the present study. T2-weighted signal intensity MRI was performed 3 times: preoperatively, immediately postoperatively, and at the final follow-up examination. We measured the cross-sectional area of the MFM on both sides (ipsilaterally and contralaterally) and recorded the operative times. The association between the interval from surgery to the final follow-up MRI and changes in the MFMs and between the operative time and changes in the MFMs were analyzed. For the group comparisons, the patients were divided into 3 groups according to the follow-up interval. Group 1 was followed up within 2 weeks, group 2 within 2-4 weeks, and group 3 after 4 weeks. The MFM changes were recorded. RESULTS: The operative time correlated significantly with the percentage of change in the T2-weighted signal intensity ratio (SIR) for both sides (P < 0.01). At the final follow-up examination, the SIR of the ipsilateral side had decreased in group 3 (P = 0.002). The percentage of change in the SIR was smallest in group 3 (P = 0.004). CONCLUSIONS: The MFM change on MRI after BESS became significant on both sides as the operative time increased. However, the change showed a tendency to reverse within several months, and no substantial change in the MFM cross-sectional area was found. We have concluded that MFM changes after BESS might correlate with an increased operative time but will resolve over time.

Relationship between lumbar multifidus muscles and degeneration of facet joint with MRI / 实用医学杂志

Objectives To investigate the relationship between the degeneration of lumbar multifidus mus-cles and facet joint osteoarthritis(FJOA)by MRI. Methods This retrospective study included 248 patients with low back and leg pain,aged from 55 to 70.MRI was used to measure TCSA,FCSA,fCSA and FI% of the L4~5and L5~S1segments on the both sides of their multifidus muscle in the cross section in T2weighted image.All the cases were divided into three grades:grade 0~1,grade 2 and grade 3 according to their FJOA grades. The relationship between the FJOA grades at the same level and TCSA,FCSA and FI% of both sides was analyzed retrospectively. Results There were significant differences of the FI% of the multifidus muscle between both sides of the two seg-ments(P < 0.05);The TCSA,FCSA and fCSA of the left and right multifidus muscle all showed an increasing trend from L4~5to L5~S1segment and the difference was statistically significant(P<0.05);the FI% of two sides of multifidus muscle was negatively correlated with the right FJOA grade at L5~S1segment(P<0.05).There was a re-lationship between females and right FJOA grade at L5~S1segment(all P < 0.05). Whereas,no significant differ-ence was found in other parameters(all P>0.05).Conclusions There is no relationship between the cross-sec-tional area of the multifidus muscle and the FJOA grade. The higher FI% degree of multifidus muscle in the L5~S1 segment is accompanied with a lower grade of FJOA.The degeneration of multifidus muscle occurs earlier than the degeneration of articular process joints,so the earlier exercise of lumbar muscle is recommended.

Test-retest reliability of measurements of abdominal and multifidus muscles using ultrasound imaging in adults aged 50-79 years.

Test-retest reliability of the combined process of ultrasound imaging (USI) and image measurement of thickness of abdominal and upper lumbar multifidus (MF) muscles and MF cross sectional area (CSA) of older adults has not been established. Imaging muscles of older adults can be challenging due to age-related changes in the spine and skeletal muscle so establishing test-retest reliability in this population is important. This study aimed to evaluate test-retest reliability of USI of abdominal and MF muscle thickness and MF CSA for adults aged 50-79 years. One operator took single sets of ultrasound images of abdominal and MF muscles of 23 adults aged 50-79 years participating in a clinical trial of vitamin D supplementation for knee osteoarthritis, on two occasions, one week apart. Images were subsequently measured by a single examiner. Test-retest reliability for abdominal muscle thickness and MF CSA was substantial (intraclass correlation coefficients (ICC) > 0.81) and for MF thickness ranged from fair to substantial (ICC 0.55-0.86). The standard error of measurement (SEM) was low (0.02-0.21) in every case. ICCs were low and SEM values were high for percentage thickness change. The substantial test-retest reliability of abdominal and MF (L4-L5) muscle thickness and of MF CSA supports the use of USI as a clinical and research tool to assess abdominal and MF muscle thickness and MF CSA of older adults.

The assessment of abdominal and multifidus muscles and their role in physical function in older adults: a systematic review.

BACKGROUND: Age-related changes in the trunk (abdominal and lumbar multifidus) muscles and their impact on physical function of older adults are not clearly understood. OBJECTIVES: To systematically summarise studies of these trunk muscles in older adults. DATA SOURCES: Cochrane Library, Pubmed, EMBASE and CINAHL were searched using terms for abdominal and MF muscles and measurement methods. STUDY SELECTION: Two reviewers independently assessed studies and included those reporting measurements of abdominal muscles and/or MF by ultrasound, computed tomography, magnetic resonance imaging or electromyography of adults aged ≥50 years. DATA SYNTHESIS: A best evidence synthesis was performed. RESULTS: Best evidence synthesis revealed limited evidence for detrimental effects of ageing or spinal conditions on trunk muscles, and conflicting evidence for decreased physical activity or stroke having detrimental effects on trunk muscles. Thicknesses of rectus abdominis, internal oblique and external oblique muscles were 36% to 48% smaller for older than younger adults. Muscle quality was poorer among people with moderate-extreme low back pain and predicted physical function outcomes. LIMITATIONS: Study heterogeneity precluded meta-analysis. CONCLUSION: Overall, the evidence base in older people has significant limitations, so the role of physiotherapy interventions aimed at these muscles remains unclear. The results point to areas in which further research could lead to clinically useful outcomes. These include determining the role of the trunk muscles in the physical function of older adults and disease; developing and testing rehabilitation programmes for older people with spinal conditions and lower back pain; and identifying modifiable factors that could mitigate age-related changes.

Lumbar multifidus morphology assessed by ultrasonography in chronic lumbar disc herniation / 中华物理医学与康复杂志

Objective To observe any differences in the morphology of the lumbar multifidus (LM) muscles between normal subjects and persons with chronic lumbar disc herniation (CLDH).Methods Thirty-two persons with CLDH and thirty-five matched,healthy controls performed various maneuvers in prone lying.Ultrasound imaging was used to measure the antero-posterior diameter (A-P),lateral diameter (Lat),cross sectional area (CSA) and flattening ratio (FR) of the bilateral LM muscles at the L4/5 level.Results In the control subjects,A-P,Lat,CSA and FR were not significantly different between the left and right sides.In those with CLDH,A-P,Lat and CSA were significantly smaller on the painful side than on the no-pain side,and this difference showed asymmetry between the two sides.Average A-P,Lat,FR and muscle CSA were all significantly smaller among the CLDH subjects on both sides compared with the controls.Conclusion CLDH induces asymmetric local atrophy of the bilateral multifidus muscles which can be detected and measured using ultrasound.