Investigation of muscle activation during kinetic chain based exercises in individuals with and without forward head posture.

BACKGROUND: The Band Pull-Apart (BPA) exercise is used to strengthen the periscapular muscles. It was recently stated that the lower extremity and trunk movements should be included in the shoulder rehabilitation programs to optimize an effective energy transfer throughout the kinetic chain. OBJECTIVE: The aim of this study is to investigate the effects of kinetic chain based BPA exercise on the muscle activations of the sternocleidomasteideous (SCM) and the trapezius muscles in individuals with and without forward head posture (FHP). METHODS: Eighteen individuals with FHP and 18 individuals without FHP were included. Photographic measurements were made to identify individuals with FHP. The muscle activations of SCM, Upper Trapezius (UT), Middle Trapezius (MT), and Lower Trapezius (LT) were measured with surface EMG. BPA exercise was performed in the standing, unipedal standing, squat, unipedal squat, and Bulgarian split squat (BSS). RESULTS: There was no Group × Exercise interaction for the SCM, UT, MT, LT muscle activations, or for the UT/MT and UT/LT ratios (p> 0.05). While there was a difference in the activation of all muscles between individuals with and without FHP (p< 0.05), both ratios were similar (p> 0.05). There was a statistically significant difference between exercises for SCM, MT, and LT muscle activations (p< 0.000 for these muscles), UT/MT (p< 0.000) and UT/LT ratios (p= 0.004). SCM muscle activation in squat was lower than activation in standing (Mean Difference (MD) = 2.5% Maximal Voluntary Isometric Contractions (MVIC); p= 0.004) and in unipedal standing (MD = 2.1% MVIC; p= 0.002). MT muscle activation in squat was higher than activation in standing (MD = 9.7% MVIC), unipedal standing (MD = 7.8% MVIC), unipedal squat (MD = 6.9% MVIC) and BSS (MD = 9.4% MVIC; p< 0.000 for these positions). LT muscle activation in the squat was higher than activation in the standing (MD = 8.5% MVIC) and unipedal squat (MD = 8.1% MVIC; p< 0.004 for these positions). UT/MT ratio in the squat was lower than standing (MD = 0.3), unipedal standing (MD = 0.2) and BSS (MD = 0.3; p< 0.000 for these positions). UT/LT ratio in squat was lower than unipedal squat (MD = 0.5) and BSS (MD = 0.6; p= 0.002; for these positions). CONCLUSION: Performing the BPA exercise in the squat position is suggested in cases where lower SCM and UT muscle activation, lower UT/MT, and UT/LT ratios and higher MT and LT muscle activations are needed for individuals with and without FHP.

Reconstrução da região superior do dorso com retalho musculocutâneo do trapézio em V-Y baseado na artéria dorsal da escápula / Reconstruction of the upper region of the back with a V-Y trapezius musculocutaneous flap based on the dorsal artery of the scapula

Introdução: Defeitos na região superior do dorso geralmente são de difícil tratamento, especialmente nos casos de exposição de vértebras, meninge ou material de síntese. O fechamento primário com retalho muscular ou musculocutâneo é a melhor escolha, mas a área doadora para tratar grandes defeitos pode requerer enxertia. A preservação da artéria dorsal da escápula parece assegurar um território cutâneo maior do que o do retalho musculocutâneo do trapézio clássico baseado apenas na artéria cervical transversa. Método: Foi concebida uma ampla ilha triangular de pele sobre o músculo trapézio baseado na artéria dorsal da escápula com transferência por movimento pendular e um procedimento tipo V-Y em cinco pacientes após a extirpação de tumores malignos. Resultados: Os defeitos e as áreas doadoras foram fechados primariamente com total viabilidade dos retalhos e não foram observadas complicações além da ocorrência de seroma. Conclusão: O retalho musculocutâneo do trapézio baseado na artéria dorsal da escápula oferece segurança no tratamento de exposição óssea na região superior do dorso.

Introduction: Defects in the upper region of the back are generally difficult to treat, especially in cases of exposure of vertebrae, meninges, or synthetic material. Primary closure with a muscular or musculocutaneous flap is the best choice, but the donor area to treat large defects may require grafting. Preservation of the dorsal artery of the scapula appears to ensure a larger cutaneous territory than that of the classic trapezius musculocutaneous flap based only on the transverse cervical artery. Method: A wide triangular island of skin was designed over the trapezius muscle based on the dorsal scapular artery with pendulum transfer and a V-Y type procedure in five patients after the extirpation of malignant tumors. Results: The defects and donor areas were closed primarily with full viability of the flaps and no complications were observed other than the occurrence of seroma. Conclusion: The trapezius musculocutaneous flap based on the dorsal artery of the scapula offers safety in the treatment of bone exposure in the upper back region.

Effects of Paraspinal Intramuscular Injection of Atelocollagen in Patients with Chronic Low Back Pain: A Retrospective Observational Study.

Background/Objectives: Atelocollagen is used for soft tissue repair and reconstruction by replacing defective or damaged muscles, membranes, ligaments, and tendons. This study aimed to evaluate the clinical efficacy and safety of additional paraspinal intramuscular injection of atelocollagen on lumbar epidural steroid injection for reducing pain and improving functional capacity of patients with chronic low back pain (CLBP). Methods: We retrospectively enrolled 608 consecutive patients with CLBP who received lumbar epidural steroid injection with or without additional paraspinal intramuscular injection of atelocollagen. The Numerical Rating Scale and the Oswestry Disability Index were used to assess pain and functional capacity, respectively, before the procedure, and three months after the injection. Also, we analyzed the relationship between the additional paraspinal intramuscular injection of atelocollagen and the success rate. Results: Both Numerical Rating Scale and the Oswestry Disability Index scores were significantly reduced in both groups at three months after injection. However, there was a significant difference between the two groups. Furthermore, the success rate was significantly higher in the additional paraspinal intramuscular injection of atelocollagen group. Conclusions: This study's results showed that additional paraspinal intramuscular injection of atelocollagen on lumbar epidural steroid injection reduced pain and improved functional capacity for patients with CLBP. Therefore, the paraspinal intramuscular injection of atelocollagen may be a promising option for the treatment of patients with CLBP.

Chronic low back pain and muscle activity in women during the sit-to-stand task: A cross-sectional study.

INTRODUCTION: The ability to stand up and sit down is important. Due to the large number of repetitions of these activities during the day and the demand that the task requires, it is cited as painful in the presence of low back pain (LBP). Individuals with LBP present alterations in muscle activation, however, this statement needs to be verified during everyday situations like the sit-to-stand task (STST). Therefore, the objective was to evaluate the muscle recruitment of women with and without LBP during the STST. METHODS: 35 women were evaluated, and allocated into the control group (CG n = 15) and the low back pain group (LBPG n = 20). The protocol consisted of clinical evaluation and the sit-to-stand task (STST). Electromyographic signals of the lumbar multifidus (LM), internal oblique (IO) and external oblique (EO), rectus abdominis (RA), and lumbar iliocostalis (LI) were carried out concomitantly with the STST. To verify normality, the Shapiro-Wilk test was used. For the characterization of the sample, the MANOVA test was chosen and the MANCOVA test was also chosen to compare the characteristics of the participants. RESULTS: Regarding the data analysis of the electromyographic signals, higher values were seen in the RA (moments 2 and 3) in the LBPG in the STST. CONCLUSION: The present study showed that women with chronic LBP present higher muscle activation of the rectus abdominis in the sit-to-stand task.

Investigating the associations between lumbar paraspinal muscle health and age, BMI, sex, physical activity, and back pain using an automated computer-vision model: a UK Biobank study.

BACKGROUND CONTEXT: The role of lumbar paraspinal muscle health in back pain (BP) is not straightforward. Challenges in this field have included the lack of tools and large, heterogenous datasets to interrogate the association between muscle health and BP. Computer-vision models have been transformative in this space, enabling the automated quantification of muscle health and the processing of large datasets. PURPOSE: To investigate the associations between lumbar paraspinal muscle health and age, sex, BMI, physical activity, and BP in a large, heterogenous dataset using an automated computer-vision model. DESIGN: Cross-sectional study. PATIENT SAMPLE: Participants from the UK Biobank with abdominal Dixon fat-water MRI (N=9,564) were included (41.8% women, mean [SD] age: 63.5 [7.6] years, BMI: 26.4 [4.1] kg/m2) of whom 6,953 reported no pain, 930 acute BP, and 1,681 chronic BP. OUTCOME MEASURES: Intramuscular fat (IMF) and average cross-sectional area (aCSA) were automatically derived using a computer-vision model for the left and right lumbar multifidus (LM), erector spinae (ES), and psoas major (PM) from the L1 to L5 vertebral levels. METHODS: Two-tailed partial Pearson correlations were generated for each muscle to assess the relationships between the muscle measures (IMF and aCSA) and age (controlling for BMI, sex, and physical activity), BMI (controlling for age, sex, and physical activity), and physical activity (controlling for age, sex, and BMI). One-way ANCOVA was used to identify sex differences in IMF and aCSA for each muscle while controlling for age, BMI, and physical activity. Similarly, one-way ANCOVA was used to identify between-group differences (no pain, acute BP, and chronic BP) for each muscle and along the superior-inferior expanse of the lumbar spine while controlling for age, BMI, sex, and physical activity (α=0.05). RESULTS: Females had higher IMF (LM mean difference [MD]=11.1%, ES MD=10.2%, PM MD=0.3%, p<.001) and lower aCSA (LM MD=47.6 mm2, ES MD=350.0 mm2, PM MD=321.5 mm2, p<.001) for all muscles. Higher age was associated with higher IMF and lower aCSA for all muscles (r≥0.232, p<.001) except for LM and aCSA (r≤0.013, p≥.267). Higher BMI was associated with higher IMF and aCSA for all muscles (r≥0.174, p<.001). Higher physical activity was associated with lower IMF and higher aCSA for all muscles (r≥0.036, p≤.002) except for LM and aCSA (r≤0.010, p≥.405). People with chronic BP had higher IMF and lower aCSA than people with no pain (IMF MD≤1.6%, aCSA MD≤27.4 mm2, p<.001) and higher IMF compared to acute BP (IMF MD≤1.1%, p≤.044). The differences between people with BP and people with no pain were not spatially localized to the inferior lumbar levels but broadly distributed across the lumbar spine. CONCLUSIONS: Paraspinal muscle health is associated with age, BMI, sex, and physical activity with the exception of the association between LM aCSA and age and physical activity. People with BP (chronic>acute) have higher IMF and lower aCSA than people reporting no pain. The differences were not localized but broadly distributed across the lumbar spine. When interpreting measures of paraspinal muscle health in the research or clinical setting, the associations with age, BMI, sex, and physical activity should be considered.

Quantifying lumbar paraspinal intramuscular fat: Accuracy and reliability of automated thresholding models.

Background: The reported level of lumbar paraspinal intramuscular fat (IMF) in people with low back pain (LBP) varies considerably across studies using conventional T1- and T2-weighted magnetic resonance imaging (MRI) sequences. This may be due to the different thresholding models employed to quantify IMF. In this study we investigated the accuracy and reliability of established (two-component) and novel (three-component) thresholding models to measure lumbar paraspinal IMF from T2-weighted MRI. Methods: In this cross-sectional study, we included MRI scans from 30 people with LBP (50% female; mean (SD) age: 46.3 (15.0) years). Gaussian mixture modelling (GMM) and K-means clustering were used to quantify IMF bilaterally from the lumbar multifidus, erector spinae, and psoas major using two and three-component thresholding approaches (GMM2C; K-means2C; GMM3C; and K-means3C). Dixon fat-water MRI was used as the reference for IMF. Accuracy was measured using Bland-Altman analyses, and reliability was measured using ICC3,1. The mean absolute error between thresholding models was compared using repeated-measures ANOVA and post-hoc paired sample t-tests (α = 0.05). Results: We found poor reliability for K-means2C (ICC3,1 ≤ 0.38), moderate to good reliability for K-means3C (ICC3,1 ≥ 0.68), moderate reliability for GMM2C (ICC3,1 ≥ 0.63) and good reliability for GMM3C (ICC3,1 ≥ 0.77). The GMM (p < .001) and three-component models (p < .001) had smaller mean absolute errors than K-means and two-component models, respectively. None of the investigated models adequately quantified IMF for psoas major (ICC3,1 ≤ 0.01). Conclusions: The performance of automated thresholding models is strongly dependent on the choice of algorithms, number of components, and muscle assessed. Compared to Dixon MRI, the GMM performed better than K-means and three-component performed better than two-component models for quantifying lumbar multifidus and erector spinae IMF. None of the investigated models accurately quantified IMF for psoas major. Future research is needed to investigate the performance of thresholding models in a more heterogeneous clinical dataset and across different sites and vendors.

Digital therapeutics-based lumbar core exercise for patients with low back pain: A prospective exploratory pilot study.

Objective: This study aimed to implement a digital therapeutics-based approach based on motion detection technology and analyze the clinical results for patients with chronic low back pain (LBP). Methods: A prospective, single-arm clinical trial was conducted with 22 patients who performed mobile app-based sitting core twist exercise for 12 weeks. Clinical outcomes were assessed using the visual analog scale (VAS) for LBP, Oswestry Disability Index-Korean version (K-ODI), and EuroQol-5 dimension 5-level version (EQ-5D-5L) every 4 weeks after the initiation of treatment. Laboratory tests for factors associated with muscle metabolism, plain X-ray for evaluating sagittal balance, and magnetic resonance imaging for calculating cross-sectional area (CSA) of back muscles were performed at pretreatment and 12 weeks post-treatment. Results: The study population included 20 female patients with an average age of 45.77 ± 15.45 years. The clinical outcomes gradually improved throughout the study period in the VAS for LBP (from 6.05 ± 2.27 to 2.86 ± 1.86), K-ODI (from 16.18 ± 6.19 to 8.64 ± 5.58), and EQ-5D-5L (from 11.09 ± 3.24 to 7.23 ± 3.89) (p < 0.001, respectively). The laboratory test results did not show significant changes. Pelvic incidence (from 53.99 ± 9.70° to 50.80 ± 9.20°, p = 0.002) and the mismatch between pelvic incidence and lumbar lordosis (from 8.97± .67° to 5.28 ± 8.57°, p = 0.027) decreased significantly. Additionally, CSA of erector spinae and total back muscles increased by 5.20% (p < 0.001) and 3.08% (p = 0.013), respectively. Conclusions: The results of this study suggest that the efficacy of digital therapy-based lumbar core exercise for LBP is favorable. However, further large-scale randomized controlled studies are necessary.

Hamstring and knee injuries are associated with isometric hip and trunk muscle strength in elite Australian Rules and Rugby League players.

OBJECTIVES: This study investigated relationships between isometric trunk and hip extensor strength, lumbar muscle morphology, and the risk of hamstring and knee ligament injuries in Australian Football League and National Rugby League players. DESIGN: Prospective cohort study. METHODS: Trunk and hip extensor strength, multifidus and quadratus lumborum cross-sectional area were measured during the 2020 pre-season. Logistic regressions and decision trees were employed to explore associations between maximum strength, strength endurance, multifidus and quadratus lumborum cross-sectional area, age, previous injuries, and hamstring and knee ligament injury risk. RESULTS: Greater strength endurance [odds ratio = 0.42 (0.23-0.74), p = 0.004] and maximum strength [odds ratio = 0.55 (0.31-0.94), p = 0.039] reduced hamstring injury risk. Increased risk of knee ligament injuries was associated with larger multifidus [odds ratio = 1.66 (1.14-2.45), p = 0.008] and higher multifidus to quadratus lumborum ratio (odds ratio = 1.57 (1.13-2.23), p = 0.008]. Decision tree models indicated that low strength endurance (< 99 Nm) characterised hamstring strains, while high (≥ 1.33) multifidus to quadratus lumborum ratio mitigated risk. Knee ligament injuries were associated with larger (≥ 8.49 cm2) multifidus, greater (≥ 1.25) multifidus to quadratus lumborum ratio, and lower maximum strength (< 9.24 N/kg). CONCLUSIONS: Players with lower trunk and hip extensor maximum strength and strength endurance had increased risk of hamstring injuries, while knee ligament injury risk was elevated with larger multifidus cross-sectional area, higher multifidus to quadratus lumborum ratio, and lower maximum trunk and hip extensor strength.

Latissimus dorsi flap with immediate fat transfer (LIFT) for autologous breast reconstruction: Single institution experience.

BACKGROUND: Few studies have reported the outcomes of LDF and immediate fat transfer (LIFT) during breast reconstruction. The aim of this study was to compare the perioperative outcomes and complications of LIFT and standard LDF (without immediate fat transfer) for breast reconstruction. METHODS: We retrospectively reviewed charts from patients undergoing autologous breast reconstruction after total mastectomy between 2011 and 2021. We compared intraoperative and postoperative outcomes between groups. RESULTS: One hundred nineteen reconstructions (61.02%) were performed with LIFT, while seventy-six (38.98%) were performed with standard LDF. The median volume of total fat transferred during LIFT was 125-cc [110-170 â€‹cc]. The rates of donor site wound disruption (23.7% versus 12.6%, p â€‹= â€‹0.044) were higher using the standard LDF compared to LIFT. Reconstructions performed with LIFT (HR 4.01, p â€‹< â€‹0.001) were found to be associated with secondary fat grafting procedures. CONCLUSION: LIFT is a safe procedure to enhance the volume of LDF in patients desiring autologous reconstruction without increasing recipient-site morbidity. On a time-to-event analysis, LIFT was associated with the requirement of further revision procedures using secondary fat grafting.

The effects of back extensor strength in different body positions on health-related quality of life in patients with degenerative spinal deformity.

BACKGROUND: Degenerative spinal deformity (DSD) is believed to originate from degeneration of the discs and facet joints and vertebral wedging. Currently, the nosogeny of DSD is not yet fully clarified and there has been no systematic study on the impact of their lower back muscle strength on quality of life. OBJECTIVE: To determine the characteristics of back extensor strength (BES) in different body positions and examine their correlations with health-related quality of life (HQOL) in degenerative spinal deformity (DSD) patients. METHODS: Participants comprised 60 DSD patients and 40 healthy volunteers. Maximal isometric BES was evaluated by dynamometers with the subject in three different positions (standing, prone, sitting). The visual analogue scale (VAS) score, Oswestry Disability Index (ODI), Roland-Morris Disability Questionnaire (RMQ), and 36-item Short Form Health Survey (SF-36) score were used to evaluate patient HQOL. Correlations between the BES in different body positions and HQOL were analysed. RESULTS: The BES values in three body positions were significantly smaller in DSD patients than healthy subjects (P< 0.05). The standing BES was found to be negatively associated with ODI and RMQ (R= 0.313, p< 0.05 and R= 0.422, p< 0.01, respectively). A negative relationship between sitting BES and RMQ was also seen (R= 0.271, p< 0.05). In addition, the standing and prone BES were positively correlated with the physical functioning score of the SF-36 (R= 0.471, p< 0.01 and R= 0.289, p< 0.05, respectively), and the sitting BES was positively correlated with the role-physical score of the SF-36 (R= 0.436, p< 0.01). CONCLUSION: The results indicate that the back extensor muscle is compromised in DSD patients and there are differences in predicting the severity of disability and physical HQOL scores with BES in different positions. Standing BES was the most reliable contributor to HQOL among three body positions.

Evaluation of the Reproducibility of MR Elastography Measurements of the Lumbar Back Muscles.

BACKGROUND: MR elastography (MRE) may provide quantitative imaging biomarkers of lumbar back muscles (LBMs), complementing MRI in spinal diseases by assessing muscle mechanical properties. However, reproducibility analyses for MRE of LBM are lacking. PURPOSE: To assess technical failure, within-day and inter-day reproducibility, robustness with the excitation source positioning, and inter-observer agreement of MRE of muscles. STUDY TYPE: Prospective. SUBJECTS: Seventeen healthy subjects (mean age 28 ± 4 years; 11 females). FIELD STRENGTH/SEQUENCE: 1.5 T, gradient-echo MRE, T1-weighted turbo spin echo. ASSESSMENT: The pneumatic driver was centered at L3 level. Four MRE were performed during two visits, 2-4 weeks apart, each consisting of two MRE with less than 10 minutes inter-scan interval. At Visit 1, after the first MRE, the coil and driver were removed, then reinstalled. The MRE was repeated. At Visit 2, following the first MRE, only the driver was moved down 5 cm. The MRE was repeated. Two radiologists segmented the multifidus and erector spinae muscles. STATISTICAL TESTS: Paired t-test, analysis of variance, intraclass correlation coefficients (ICCs). P-values <0.05 were considered statistically significant. RESULTS: Mean stiffness of LBM ranged from 1.44 to 1.60 kPa. Mean technical failure rate was 2.5%. Inter-observer agreement was excellent (ICC ranging from 0.82 [0.64-0.96] to 0.99 [0.98-0.99] in the multifidus, and from 0.85 [0.69-0.92] to 0.99 [0.97-0.99] in the erector spinae muscles). Within-day reproducibility was fair in the multifidus (ICC: 0.53 [0.47-0.77]) and good in the erector spinae muscles (ICC: 0.74 [0.48-0.88]). Reproducibility after moving the driver was excellent in both multifidus (ICC: 0.85 [0.69-0.93]) and erector spinae muscles (ICC: 0.84 [0.67-0.92]). Inter-day reproducibility was excellent in the multifidus (ICC: 0.76 [0.48-0.89]) and poor in the erector spinae muscles (ICC: 0.23 [-0.61 to 0.63]). DATA CONCLUSION: MRE of LBM provides measurements of stiffness with fair to excellent reproducibility and excellent inter-observer agreement. However, inter-day reproducibility in the multifidus muscles indicated that the herein used MRE protocol may not be optimal for this muscle. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 1.

Potential of whole-body dual-energy X-ray absorptiometry to predict muscle size of psoas major, gluteus maximus and back muscles.

BACKGROUND: Measurement of trunk muscle cross-sectional area (CSA) using axial magnetic resonance imaging (MRI) is considered clinically meaningful for understanding several spinal pathologies, such as low back pain and spinal sagittal imbalance. However, it remains unclear whether trunk muscle mass (TMM) measured using dual-energy X-ray absorptiometry (DXA) can predict the trunk muscle CSA. The aim of this study is to determine if DXA-derived TMM is associated and predicts with CSA of paraspinal muscles and gluteus maximus measured using MRI in healthy volunteers. METHODS: A total of 48 healthy volunteers underwent whole-body DXA and MRI of the spinopelvic region. The CSA of the psoas major, back muscles, and gluteus maximus were measured on axial MRI. Correlations and linear regressions between the TMM measured using DXA and the CSA of each musculature were investigated. RESULTS: There was a weak correlation between TMM and CSA of the psoas major in men (r = 0.39, P = 0.0678), and the linear regression was y = 301.74x - 401.24 (R2 = 0.2976, P = 0.0070). A moderate correlation was found in women (r = 0.58, P = 0.0021), and the linear regression was y = 230.21x - 695.29 (R2 = 0.4445, P = 0.0003). Moderate correlations were observed between TMM and CSA of the back muscles in both men (r = 0.63, P = 0.0012) and women (r = 0.63, P = 0.0007), the linear regression was y = 468.52x + 3688.5 (R2 = 0.5505, P < 0.0001) in men and y = 477.39x + 2364.1 (R2 = 0.564, P < 0.0001) in women. There was a strong correlation between TMM and CSA of the gluteus maximus in men (r = 0.72, P < 0.0001), and the linear regression was y = 252.69x - 880.5 (R2 = 0.6906, P < 0.0001). A moderate correlation was found in women (r = 0.69, P < 0.0001), and the linear regression was y = 230.74x - 231.32 (R2 = 0.6542, P < 0.0001). CONCLUSIONS: The DXA-derived TMM was able to predict the CSA of the psoas major, back muscles, and gluteus maximus, and significantly correlated with the CSA of the back muscles and gluteus maximus. It might be a safer and cheaper alternative for evaluating the size of the back muscles and gluteus maximus.

The Relationship Between Low Back Pain and Sagittal Spinal Alignment and Back Muscle Mass in Korean Fishery Workers.

OBJECTIVE: To investigate the relationship between low back pain (LBP) and sagittal spino-pelvic parameters along with the relationship between LBP and back muscle mass in Korean male and female fishery workers. METHODS: This retrospective study included a total of 146 subjects who underwent Fishermen's health survey conducted between June 2018 and August 2020. LBP was evaluated through visual analogue scale (VAS) and Oswestry Disability Index (ODI). Sagittal spino-pelvic parameters were measured from whole spine standing X-rays. Back muscle cross-sectional areas were identified through lumbar spine magnetic resonance imaging and body composition was analyzed through bioelectrical impedance analysis. RESULTS: The study included 75 males and 71 females, with an average age of 58.33 years for males and 56.45 years for females. Female subjects exhibited higher VAS and ODI scores, larger pelvic tilt (PT) and trunk fat mass and smaller trunk muscle mass compared to males. In female, ODI positively correlated with sagittal vertical axis (SVA) and PT. No significant correlations were found between ODI scores and body composition in either sex. The high ODI group showed greater SVA, PT, and pelvic incidence-lumbar lordosis and higher trunk fat/muscle ratio. Psoas muscle mass, total and skeletal muscle mass and trunk muscle mass of that group were smaller than those of low ODI group. CONCLUSION: Spino-pelvic parameters and back muscle mass were associated with ODI and there were differences between Korean male and female fishery workers.

Breast reconstruction with latissimus dorsi flap: a comprehensive review and case series.

The latissimus dorsi flap (LDF) has gained popularity given its versatile nature and broad applicability in breast reconstruction. Its resurgence has been attributed to its ability to be enhanced using implant or high-volume fat grafting, rendering it a primary option for selected patients. The aim of this review is to tackle current indications and subjects of controversy regarding use of complete-autologous and implant-enhanced LDF in breast reconstruction. Also, a case-series showcasing the authors' experience with this versatile reconstructive option is presented. A search across Web of Science and PubMed MEDLINE from inception through January 3, 2023, was conducted. Articles reporting postoperative outcomes of autologous breast reconstruction with LDF were included. Regarding the case series, electronic medical records of patients who underwent total mastectomy and autologous breast reconstruction with LDF from January 2011 to December 2021 were retrospectively reviewed. Data on demographic and oncologic characteristics, and surgical characteristics and outcomes were extracted. Our review suggests that LDF is suitable for patients who lack alternative donor site, have a history of abdominoplasty or no access to microsurgery, smokers or obese. Latissimus dorsi (LD) harvesting has almost complete shoulder function recovery in the long-term. Thoracodorsal nerve division does not cause volume loss or animation deformity. Multisite multilayer fat grafting, beveling the edges of the skin paddle and fat, folding the LD muscle and plicating the paddle allow adequate projection and contour achievement. Our case-series included 234 reconstructions. Almost half of the patients had immediate fat transfer during reconstruction (51.3%). The rate of recipient site hematoma was 3.0%, seroma was 7.7%, wound disruption 32.1%, wound disruption events requiring unplanned procedures was 13.7%, and surgical site infection (SSI) was 12.4%. The LDF is reliable and safe for immediate or delayed breast reconstruction or salvage after reconstruction failure. Its versatility, reliable anatomy, easy dissection, and relative low complication rate have revived this modality as valuable opportunity for breast reconstruction in this era.

Simulation of passive exotendon assistive device for agricultural harvesting task.

This study proposes and investigates the feasibility of the passive assistive device to assist agricultural harvesting task and reduce the Musculoskeletal Disorder (MSD) risk of harvesters using computational musculoskeletal modelling and simulations. Several passive assistive devices comprised of elastic exotendon, which acts in parallel with different back muscles (rectus abdominis, longissimus, and iliocostalis), were designed and modelled. These passive assistive devices were integrated individually into the musculoskeletal model to provide passive support for the harvesting task. The muscle activation, muscle force, and joint moment were computed with biomechanical simulations for unassisted and assisted motions. The simulation results demonstrated that passive assistive devices reduced muscle activation, muscle force, and joint moment, particularly when the devices were attached to the iliocostalis and rectus abdominis. It was also discovered that assisting the longissimus muscle can alleviate the workload by distributing a portion of it to the rectus abdominis. The findings in this study support the feasibility of adopting passive assistive devices to reduce the MSD risk of the harvesters during agricultural harvesting. These findings can provide valuable insights to the engineers and designers of physical assistive devices on which muscle(s) to assist during agricultural harvesting.

Influence of scapular motion cues on trapezius muscle activity during Y exercise.

BACKGROUND: The Y exercise is a therapeutic exercise facilitating lower trapezius muscle activity. OBJECTIVE: To identify the effects of scapular movement cues (posterior tilt vs. posterior tilt with adduction/depression) on trapezius muscle activity during Y exercise. METHODS: Fifteen healthy men without current shoulder pain performed general Y exercise; Y exercise with cues for scapular posterior tilt; and Y exercise with cues for scapular posterior tilt, adduction, and depression. Electromyography (EMG) data for the trapezius muscles were collected during Y exercise. The posterior tilt angle of the scapula was measured in the prone position with and without cues for scapular posterior tilt using an inclinometer application. RESULTS: The greatest lower trapezius muscle activity was observed during Y exercise with cues for scapular posterior tilt, while the greatest EMG activity of the upper trapezius was observed during Y exercise with cues for scapular posterior tilt, adduction, and depression (p< 0.05). Middle trapezius muscle activity did not significantly differ among the three Y exercise conditions (p= 0.175). Cues for scapular posterior tilt significantly increased the scapular posterior tilt angle in the prone shoulder abduction position (p= 0.007). CONCLUSION: Cues for scapular posterior tilt were most effective in facilitating lower trapezius muscle activity during Y exercise.

Dermatofibrosarcoma protuberans de mama con reconstrucción con colgajo del dorsal ancho. Reporte de caso

El Dermatofibrosarcoma Protuberans es un tumor cutáneo fibrohistiocítico, extremadamente raro y representa menos del 1% de los tumores mamarios. Se caracteriza por un lento crecimiento, pero con comportamiento infiltrante con altas tasas de recidiva local. Se puede sospechar clínicamente, la confirmación es histopatológica y se debe complementar con inmunohistoquímica. El tratamiento de elección es quirúrgico. Se presenta el caso de una mujer de 23 años con Dermatofibrosarcoma Protuberans de mama derecha, sometida a tumorectomía y reconstrucción inmediata de colgajo de dorsal ancho. La paciente tuvo evolución satisfactoria, sin evidencia de enfermedad.

SUMMARY Dermatofibrosarcoma protuberans is a fibro histiocytic cutaneous tumor extremely rare that accounts for less than 1% of all breast cancers, and it is characterized by slow growing but locally invasiveness with high recurrence rates. Confirmation of the diagnosis is with histopathology with immunohistochemistry. Treatment of choice is surgical resection with latissimus dorsalis reconstruction. We present the case of a 23-year-old woman with dermatofibrosarcoma protuberans of the right breast in whom a tumorectomy followed by latissimus dorsalis reconstruction was performed. The patient had a favorable clinical evolution remaining free of disease.

A Dynamic Procedure to Detect Maximum Voluntary Contractions in Low Back.

Surface electromyography (sEMG) is generally used to measure muscles' activity. The sEMG signal can be affected using several factors and vary among individuals and even measurement trials. Thus, to consistently evaluate data among individuals and trials, the maximum voluntary contraction (MVC) value is usually calculated and used to normalize sEMG signals. However, the sEMG amplitude collected from low back muscles can be frequently larger than that found when conventional MVC measurement procedures are used. To address this limitation, in this study, we proposed a new dynamic MVC measurement procedure for low back muscles. Inspired by weightlifting, we designed a detailed dynamic MVC procedure, and then collected data from 10 able-bodied participants and compared their performances using several conventional MVC procedures by normalizing the sEMG amplitude for the same test. The sEMG amplitude normalized by our dynamic MVC procedure showed a much lower value than those obtained using other procedures (Wilcoxon signed-rank test, with p < 0.05), indicating that the sEMG collected during dynamic MVC procedure had a larger amplitude than those of conventional MVC procedures. Therefore, our proposed dynamic MVC obtained sEMG amplitudes closer to its physiological maximum value and is thus more capable of normalizing the sEMG amplitude for low back muscles.

Age-Related Differences in Trunk Kinematics and Interplanar Decoupling with the Pelvis during Gait in Healthy Older versus Younger Men.

This study investigated age-related differences in trunk kinematics during walking in healthy men. Secondary aims were to investigate the covarying effects of physical activity (PA) and lumbar paravertebral muscle (LPM) morphology on trunk kinematics, and the effect of age on interplanar coupling between the trunk and pelvis. Three-dimensional (3D) trunk and pelvis motion data were obtained for 12 older (67.3 ± 6.0 years) and 12 younger (24.7 ± 3.1 years) healthy men during walking at a self-selected speed along a 10 m walkway. Phase-specific differences were observed in the coronal and transverse planes, with midstance and swing phases highlighted as instances when trunk and pelvic kinematics differed significantly (p < 0.05) between the younger group and older group. Controlling for age, fewer significant positive correlations were revealed between trunk and pelvic ranges and planes of motion. LPM morphology and PA were not significant covariates of age-related differences in trunk kinematics. Age-related differences in trunk kinematics were most apparent in the coronal and transverse planes. The results further indicate ageing causes an uncoupling of interplanar upper body movements during gait. These findings provide important information for rehabilitation programmes in older adults designed to improve trunk motion, as well as enable identification of higher-risk movement patterns related to falling.

Differences in the elastic modulus of the lumbar muscles between female athletes with and without low back pain.

BACKGROUND: Low back pain is the most prevalent musculoskeletal disorder affecting performance and sports participation among athletes and is more prevalent among female athletes. Evaluating the stiffness of the lumbar muscles is important for understanding the pathophysiology of low back pain. Therefore, this study examined the differences in stiffness of the lumbar multifidus and erector spinae muscles between female university athletes with and without low back pain. METHODS: This was a cross-sectional study. The study was conducted at a single centre, the university research laboratory. Twenty female university athletes with low back pain or a history of low back pain and 20 without low back pain participated in this study. The shear elastic moduli of the multifidus and erector spinae muscles were evaluated in the prone (to relax the muscles) and sitting with 35° of trunk flexion (to stretch the muscles) positions using shear wave ultrasound imaging equipment. FINDINGS: The low back pain group showed significantly greater shear elastic modulus in the multifidus in both prone and sitting positions than the non-low back pain group. There were no differences in the erector spinae muscle between the two groups at either position. INTERPRETATION: These results provide new insights into the microscopic characteristics of low back pain pathophysiology in young female athletes. Stiffness assessment using shear wave elastography will help provide a specific treatment strategy for female athletes with low back pain or a history of low back pain.