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Few biomechanical models of sitting stability have been proposed over the last decades and most of them control the trunk position through a lumbar torque. Unfortunately, this type of model is not valid for individuals living with a complete thoracic spinal cord injury (SCI) who generally experience paralysis of their abdominal and lower back muscles. Instead, individuals with SCI often engage their upper limbs as a compensatory strategy to control their sitting position. A new nonlinear biomechanical model is introduced to take into consideration the influence of the upper limbs for sitting control study of people living with SCI. The inherent nonlinearity of the model is taken into account via the Takagi–Sugeno (T‐S) framework. To estimate the internal controlling torques without measurements, an unknown input observer (UIO) is created. Its convergence is expressed by linear matrix inequalities (LMI), which are solved by convex optimization techniques. Numerical simulations with perturbations are used to assess the adequacy of the methodology and preliminary experimental data of one person living with SCI performing a sitting stabilization exercise is used to estimate internal torques of the upper limbs. The main contribution of this work is to provide a way to estimate human joint torques without invasive measurements; the results highlight the validity of both goals of this article, the nonlinear biomechanical modelling and the UIO methodology. [ABSTRACT FROM AUTHOR]

Few non-surgical, longitudinal studies have evaluated the relations between spinal degeneration, lumbar multifidus muscle (LMM) quality, and clinical outcomes. None have assessed the potential mediating role of the LMM between degenerative pathology and 12-month clinical outcomes. This prospective cohort study used baseline and 12-month follow-up data from 569 patients conservatively managed for low back or back-related leg pain to estimate the effects of aggregate degenerative lumbar MRI findings and LMM quality on 12-month low back and leg pain intensity (0–10) and disability (0–23) outcomes, and explored the mediating role of LMM quality between degenerative findings and 12-month clinical outcomes. Adjusted mixed effects generalized linear models separately estimated the effect of aggregate spinal pathology and LMM quality. Mediation models estimated the direct and indirect effects of pathology on leg pain, and pathology and LMM quality on leg pain, respectively. Multivariable analysis identified a leg pain rating change of 0.99 [0.14; 1.84] (unstandardized beta coefficients [95% CI]) in the presence of ≥ 4 pathologies, and a disability rating change of − 0.65 [− 0.14; − 1.16] for each 10% increase in muscle quality, but no effect on back pain intensity. Muscle quality had a non-significant mediating role (13.4%) between pathology and leg pain intensity. The number of different pathologies present demonstrated a small effect on 12-month leg pain intensity outcomes, while higher LMM quality had a direct effect on 12-month disability ratings but no mediating effect between pathology and leg pain. The relations between degenerative pathology, LMM quality, and pain-related outcomes appear complex and may include independent pathways. [ABSTRACT FROM AUTHOR]

Objective To demonstrate that a T2 periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) technique using deep learning reconstruction (DLR) will provide better image quality and decrease image noise. Methods From December 2020 to March 2021, 35 patients examined cervical spine MRI were included in this study. Four sets of images including fast spin echo (FSE), original PROPELLER, PROPELLER DLR50%, and DLR75% were quantitatively and qualitatively reviewed. We calculated the signal-to-noise ratio (SNR) of the spinal cord and sternocleidomastoid (SCM) muscle and the contrast-to-noise ratio (CNR) of the spinal cord by applying region-of-interest at the spinal cord, SCM muscle, and background air. We evaluated image noise with regard to the spinal cord, SCM, and back muscles at each level from C2-3 to C6-7 in the 4 sets. Results At all disc levels, the mean SNR values for the spinal cord and SCM muscles were significantly higher in PROPELLER DLR50% and DLR75% compared to FSE and original PROPELLER images (P  < .0083). The mean CNR values of the spinal cord were significantly higher in PROPELLER DLR50% and DLR75% compared to FSE at the C3-4 and 4-5 levels and PROPELLER DLR75% compared to FSE at the C6-7 level (P  < .0083). Qualitative analysis of image noise on the spinal cord, SCM, and back muscles showed that PROPELLER DLR50% and PROPELLER DLR75% images showed a significant denoising effect compared to the FSE and original PROPELLER images. Conclusion The combination of PROPELLER and DLR improved image quality with a high SNR and CNR and reduced noise. Advances in knowledge Motion-insensitive imaging technique (PROPELLER) increased the image quality compared to conventional FSE images. PROPELLER technique with a DLR reduced image noise and improved image quality. [ABSTRACT FROM AUTHOR]

Background: Mesalamine produces many side effects through oral route such as stomach cramps, throat irritation, back ache and muscle pain. Furthermore, it failed to yield maximum drug release and also not able to produce the drug release for over a period of time at the target site. To overcome these disadvantages, the current research proposed to develop microspheres with pH-dependent bio-resorbable polymers to obtain site-specific controlled drug release at the target site. Materials and Methods: Microspheres were prepared by two methods as ionic gelation and solvent evaporation methods using copolymers such as Eudragit S 100 and PLGA. Results: The prepared formulations were characterized for multiple parameters and the particle size ranges were found in between 5.52 to12.56 µm whereas percentage entrapment efficiency was found in the range of 32 to 98% respectively. Apart from other formulations, PLGA microspheres showed the maximum cumulative percentage drug release through in vitro and ex vivo and the results were found as 96±0.1% and 90.8±0.8% respectively. As compared to Pentasa®, PLGA microspheres showed two folds increase in drug release. The PLGA biodegradability was observed as maximum in the caecal content than other formulations. Conclusion: Compared to Pentasa®, the prepared PLGA microspheres showed the best results and the obtained result was verified with a p-value which is shown <0.005. Based on the results, it was concluded that the prepared PLGA microspheres showed better-controlled drug release than other test formulations. [ABSTRACT FROM AUTHOR]

Introduction. Considering that stretching can reduce neural impulses, this study aimed to verify whether stretching to paravertebral muscles changes the electromyographic activity characteristics of the lumbar multifidus. Methods. The volunteers (n = 46) were randomly allocated to four experimental conditions performed in 4 visits: control and three paravertebral stretching interventions sustained for 10, 30, and 60 s. At each visit, the electromyographic activity of the multifidus was collected in the following sequence: a) pre-intervention in the neutral orthostatic position; b) during the intervention targeted by the visit; c) post intervention in the neutral orthostatic position. Outcomes were analyzed by MatLab codes using wavelet methodology. In addition to the inferential statistics generated by the generalized estimation equation model, it presented reproducibility and responsiveness metrics. Results. Only the median frequency difference between the sustained stretches for 10 and 60 s was found. However, responsiveness measures indicated that such a difference was due to measurement variability rather than the actual change caused by the intervention. Conclusions. Stretching duration did not influence the electrical activity of the lumbar multifidus. Study registration. This study was registered at Brazilian Registry of Clinical Trials - REBEC (number: RBR-7bvg7p): http://www.ensaiosclinicos.gov.br/. [ABSTRACT FROM AUTHOR]

Introduction: Analyses related to idiopathic toe walking (ITW) are limited to the functioning of the lower-limb. It is recommended to broaden our understanding and consider other parts of the body in accordance with the principles of tensegrity. Objectives: The purpose of this study is to assess the activity of selected trunk and neck muscles in children with ITW. Material and methods: The study involved 50 children (7-10 years old). They were divided into a study group (SG): children with ITW (n=20); and a control group (CG): healthy children (n=30). The static and dynamic activity of the cervical and lumbar parts of erector spinae muscle (CES and LES, respectively) and of the sternocleidomastoid muscles was measured by sEMG. Measurements were performed on both sides of the body. Results: Statistically significant differences between SG and CG were found in the muscle activity of CES on both sides of the body with regard to statics in the neutral position (p<0.001). Differences were observed in the activity of LES between groups in statics for the neutral, hyperextension and flexion-relaxation positions on both sides of the body (p<0.001). In dynamics, statistically significant differences between groups were found: on the left and right sides of the LES in flexion, extension and rotation on the left side (p<0.05), on the left and right sides for the CES in extension, flexion on the right side, rotation on the right and left sides (p<0.05), and for the SCM, in extension and rotation on the left side (p<0.05). Conclusions: Children with ITW have disturbed tone of the trunk and neck muscles. It is advised that, apart from the ankle joints and muscles of the lower limb, physiotherapy be extended to the back and neck muscles. [ABSTRACT FROM AUTHOR]

BACKGROUND: Anterior subtotal corpectomy, decompression and fusion is a conventional method to treat cervical degenerative diseases. A titanium cage is an important implant to maintain the stability of the cervical spine after subtotal corpectomy. In recent years, many patients have complications such as titanium cage sinking, which are highly controversial. OBJECTIVE: To investigate the internal biomechanical relationship between the tilt angle of the titanium cage and postoperative titanium cage subsidence after anterior subtotal cervical corpectomy, decompression and fusion. METHODS: A three-dimensional finite element model of the C4-C6 segment was established by CT images of a normal human cervical spine, in which the anterior subtotal resection, decompression and fusion of the C5 vertebral body were simulated, and titanium cages with different tilt angles (-6° to -1° negative angle, that is, the front edge of titanium cage is shorter than the rear edge of titanium cage; 1° to 6° positive angle, that is, the front edge of titanium cage is longer than the rear edge of titanium cage) were placed. After setting the boundary conditions, preloads of 50, 100 and 150 N were applied respectively on the C4 vertebral body. The stress value of each contact point between the titanium cage and C4 lower-end plate and C6 lower-end plate (seven stress contact points on the contact surface of titanium mesh) was recorded and statistical analysis was conducted. RESULTS AND CONCLUSION: (1) The tilt angles of the titanium cage of the positive angle group and negative angle group under 50, 100 and 150 N stress respectively were found by Mann Whitn test, with P < 0.05, which was statistically significant. The dispersion coefficients of the positive angle group were smaller than those of the negative angle group under 50, 100 and 150 N stress conditions. (2) Under 50, 100 and 150 N stress conditions, the Wilcoxon sign rank test in the positive angle group of titanium cage tilt angle found that when the angle was set to 1° to 5°, the difference was not statistically significant (P > 0.05). However, when the tilt angle of the titanium cage was set to 6°, the difference was statistically significant (P < 0.05). (3) Under 50, 100 and 150 N stress conditions, the Wilcoxon sign rank test in the negative angle group of titanium cage tilt angle found that when the tilt angle was set to -1° to-6°, the difference was not statistically significant (P > 0.05). (4) It is concluded that in the sagittal position, the titanium cage with a positive tilt angle is more stable than with a negative tilt angle, which is more suitable for clinical use. The tilt angle of the titanium cage is relatively stable in the range of 1° to 5°. When the tilt angle is 6°, the stability starts to decline, which is easy to cause complications of titanium cage sinking after surgery. It is more suitable to select the titanium cage with a tilt angle of 1° to 5° according to the clinical situation during surgery to improve the efficacy. [ABSTRACT FROM AUTHOR]

Background: Chronic low back pain (LBP) related to flight is a prevalent health issue in military aviation, impacting pilots. The objective of this investigation was to ascertain if the application of core muscle training in conjunction with interferential current (IFC) therapy results in a reduction in pain severity and associated disability, consequently enhancing core muscle functionality in Chinese Air Force high-performance fighter pilots experiencing chronic LBP. Methods: Fifty-three fighter pilots with chronic LBP were randomized into 3 groups: a core muscle exercise combined with IFC group (CG, n = 19), a core muscle exercise group (EG, n = 19), and an IFC group (IG, n = 15). The three groups underwent therapeutic intervention 5 times a week for 12 weeks. The primary outcomes were pain intensity, Oswestry Disability Index (ODI) score and SF-12 health-related quality of life (PCS and MCS) score. Secondary outcomes included evaluations of trunk muscle strength, endurance, and range of motion (ROM) during medial/lateral rotation to assess muscle functionality. Measurements were obtained both before and after the implementation of the intervention therapy. Results: After 12 weeks of intervention therapy, all the health condition parameters significantly improved among the three groups. However, the CG had a significant improvement in pain intensity compared to the EG (MD = − 0.84 scores; 95% CI = − 1.54 to − 0.15; p = 0.013) and the IG (MD = − 1.22 scores; 95% CI = − 1.96 to − 0.48; p = 0.000). Additionally, the CG led to greater conservation of ODI and improved SF-12 PCS scores than did the IG (p < 0.05). Finally, compared with those at baseline, the core muscle function parameters in the CG and EG improved significantly at the end of the study, but no statistically significant differences were observed between the two groups (p > 0.05). Conclusion: Among participants with chronic LBP, three intervention therapies appear effective in reducing pain, diminishing disability, and enhancing quality of life. Also, combined therapy significantly improved pain and disability compared to the other two monotherapies; moreover, combined therapy and core muscle exercise provided similar benefits in terms of core muscle function after 12 weeks of intervention therapy. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Postoperative discitis (POD) accounts for 20% to 30% of all cases of pyogenic spondylodiscitis, while POD may be mis-or-under-diagnosed, due to the vague related symptomatology and the non-specific imaging findings. Most studies report infection rate of less than 1%, which increases with the addition of non-instrumented fusion to 2.4% to 6.2%. It remains controversial whether POD is caused by an aseptic or infectious process. Positive cultures are presented only in 42–73% of patients with Staphylococcus species being the most common invading organisms, while Staphylococcus aureus is isolated in almost 50% of cases. The onset of POD symptoms usually occurs at 2–4 weeks after an apparently uneventful operation. Back pain and muscle spasms are usually refractory to bed rest and analgesics. Magnetic Resonance Imaging (MRI) is the most sensitive and specific imaging diagnostic technique. Antimicrobial therapy depends on the results of tissue cultures, and along with bracing represents the mainstay of management. Surgical intervention is necessary in patients failing conservative treatment. For the majority of cases, extensive surgical debridement, antibiotic therapy, and orthosis immobilization are effective in eliminating the infection. According to this, we recommend an Algorithmic approach for the management of POD. Postoperative infections after spinal surgery pose a certain clinical challenge, and in most cases can be treated conservatively. Nevertheless, disability may be persistent, and surgery could be necessary. The purpose of this concise review is to describe the manifestation of post-discectomy infection, its pathogenesis and particularly a rational approach for its management. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. Prospective cohort study. 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. 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). 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. [ABSTRACT FROM AUTHOR]

Kinetic chains (KCs) are primarily affected by the load of different activities that recruit muscles from different regions. We explored the effects of strengthening exercises on KCs through muscle activation. Four databases were searched from 1990 to 2019. The muscles of each KC, their surface electromyography (sEMG), and the exercises conducted were reported. We found 36 studies that presented muscle activation using the percent (%) maximal voluntary isometric contraction (MVIC) or average sEMG for nine KCs in different regions. The % MVIC is presented as the following four categories: low (≤20%), moderate (21~40%), high (41~60%), and very high (>60%). Only four studies mentioned muscle activation in more than three KCs, while the remaining studies reported inconsistent sEMG processing, lacked normalization, and muscle activation in one or two KCs. The roles of stabilizers and the base of support in overhead throwing mobility using balance exercises were examined, and the concentric phase of chin-up and lat pull-down activated the entire KC by recruiting multiple muscles. Also, deep-water running was shown to prevent the risk of falls and enhance balance and stability. In addition, low-load trunk rotations improved the muscles of the back and external oblique activation. Based on this study's findings, closed-chain exercises activate more groups of muscles in a kinetic chain than open-chain exercises. However, no closed or open chain exercise can activate optimal KCs. [ABSTRACT FROM AUTHOR]

Background: Multidisciplinary functional restoration programs (FRPs) aim to improve pain and function in people with chronic low back pain (CLBP). The intensity and content of FRPs varies; the benefits of one program over another are unclear. Objective: To assess changes in trunk muscle strength and endurance after an intensive (IFRP) (for people on sick leave for >6 months with high levels of fear-avoidance beliefs about physical activity and work) or semi-intensive (SIFRP) (for people working) FRP in people with CLBP. Methods: Longitudinal retrospective study from March 2016 to December 2019. Setting: rehabilitation department of a tertiary care center. Trunk flexor and extensor muscle strength (60°.s−1) and endurance (120°.s−1) were measured with the Humac NORM isokinetic dynamometer at pre and post FRP. Change in isokinetic variables (peak torque, total work and flexor/extensor ratio) after each program was assessed with a paired t-test (p

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.

Injuries involving the lumbopelvic region (ie, lumbar spine, pelvis, hip) are common across the lifespan and include pathologies such as low back pain, femoroacetabular impingement syndrome, labrum tear, and osteoarthritis. Joint injury is known to result in an arthrogenic muscle response which contributes to muscle weakness and altered movement patterns. The purpose of this manuscript is to summarize the arthrogenic muscle response that occurs across lumbopelvic region pathologies, identify methods to quantify muscle function, and propose suggestions for future research. While each lumbopelvic region pathology is unique, there are a few common impairments and a relative consistent arthrogenic muscle response that occurs across the region. Hip muscle weakness and hip joint range of motion limitations occur with both lumbar spine and hip pathologies, and individuals with low back pain are known to demonstrate inhibition of the transversus abdominis and multifidus. Assessment of muscle inhibition is often limited to research laboratory settings, but dynamometers, ultrasound imaging, and electromyography offer clinical capacity to quantify muscle function and inform treatment pathways. Future studies should systematically determine the arthrogenic muscle response across multiple muscle groups and the timeline for changes in muscle function and determine whether disinhibitory modalities improve functional outcomes beyond traditional treatment approaches. [ABSTRACT FROM AUTHOR]

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.

Falls can be identified as one of the main issues in elderly population which can lead to serious consequences. Elderly population can be subdivided as community dwelling older adults and institutionalized older adults. The components of health-related physical fitness factors play an important role in the perspective of healthy ageing. The objective of the study was to determine the prevalence of falls and to compare health-related physical fitness factors between different fall categories among institutionalized older adults. This descriptive cross-sectional study comprised of one hundred and seventy-two elders above 60 years of age, living in registered elder's homes in Kandy District. The prevalence of falls was determined by the number of falls reported by the subjects. They were further categorized as non-fallers, fallers, and frequent fallers depending on the number of falls. Body Mass Index (BMI) for body composition, 2-minute walk test for cardiovascular endurance, 30 second sit to stand test for muscle strength and endurance, hand grip strength for upper body strength, chair sit and reach test for lower body flexibility and back scratch test for upper body flexibility were the measures used to assess health-related physical fitness factors. The prevalence of falls is presented as percentage and the health-related factors were compared between the three faller categories using one-way ANOVA and pairwise comparison was performed using Scheffe test. The prevalence of falls was 47.1%. There was a significant difference in BMI, cardiovascular endurance, and lower body flexibility between the three categories of fallers. Higher BMI, lower cardiovascular endurance and lower flexibility in the lower body were associated with increased prevalence of falls (p<0.05). There was no significant difference in body fat percentage, hand grip strength, lower body muscle strength and endurance and upper body flexibility (p>0.05). The findings suggest that, BMI, cardiovascular endurance, and lower body flexibility must be addressed and managed, while designing intervention programs for falls prevention among institutionalized older adults. [ABSTRACT FROM AUTHOR]

With the technological advances made to expand space exploration, astronauts will spend extended amounts of time in space before returning to Earth. This situation of unloading and reloading influences human physiology, and readaptation to full weight‐bearing may significantly impact astronauts' health. On Earth, similar situations can be observed in patients who are bedridden or suffer from sport‐related injuries. However, our knowledge of male physiology far exceeds our knowledge of female's, which creates an important gap that needs to be addressed to understand the sex‐based differences regarding musculoskeletal adaptation to unloading and reloading, necessary to preserve health of both sexes. Using a ground‐based model of total unloading for 14 days and reloading at full weight‐bearing for 7 days rats, we aimed to compare the musculoskeletal adaptations between males and females. Our results reveal the existence of significant differences. Indeed, males experienced bone loss both during the unloading and the reloading period while females did not. During simulated microgravity, males and females showed comparable muscle deconditioning with a significant decline in rear paw grip strength. However, after 7 days of recovery, muscle strength improved. Additionally, sex‐based differences in myofiber size existing at baseline are significantly reduced or eliminated following unloading and recovery. [ABSTRACT FROM AUTHOR]

Background: Elderly people are at high risk of falls due to decreased muscle strength. So far, there is currently no officially approved medication for treating muscle strength loss. The active vitamin D analogues are promising but inconsistent results have been reported in previous studies. The present study was to meta-analyze the effect of active vitamin D analogues on muscle strength and falls in elderly people. Methods: The protocol was registered with PROSPERO (record number: CRD42021266978). We searched two databases including PubMed and Cochrane Library up until August 2023. Risk ratio (RR) and standardized mean difference (SMD) with 95% confidence intervals (95% CI) were used to assess the effects of active vitamin D analogues on muscle strength or falls. Results: Regarding the effects of calcitriol (n= 1), alfacalcidol (n= 1) and eldecalcitol (n= 1) on falls, all included randomized controlled trials (RCT) recruited 771 participants. Regarding the effects of the effects of calcitriol (n= 4), alfacalcidol (n= 3) and eldecalcitol (n= 3) on muscle strength, all included RCTs recruited 2431 participants. The results showed that in the pooled analysis of three active vitamin D analogues, active vitamin D analogues reduced the risk of fall by 19%. Due to a lack of sufficient data, no separate subgroup analysis was conducted on the effect of each active vitamin D analogue on falls. In the pooled and separate analysis of active vitamin D analogues, no significant effects were found on global muscle, hand grip, and back extensor strength. However, a significant enhancement of quadriceps strength was observed in the pooled analysis and separate analysis of alfacalcidol and eldecalcitol. The separate subgroup analysis on the impact of calcitriol on the quadriceps strength was not performed due to the lack to sufficient data. The results of pooled and separate subgroup analysis of active vitamin D analogues with or without calcium supplementation showed that calcium supplementation did not affect the effect of vitamin D on muscle strength. Conclusions: The use of active vitamin D analogues does not improve global muscle, hand grip, and back extensor strength but improves quadriceps strength and reduces risk of falls in elderly population. [ABSTRACT FROM AUTHOR]

Objective: To analyze the characteristics of "severe" dynamic sagittal imbalance (DSI) in patients with adult spinal deformity (ASD) and establish criteria for them. Methods: We retrospectively analyzed 102 patients with ASD presenting four cardinal signs of lumbar degenerative kyphosis. All patients underwent deformity corrective surgery and were divided into three groups according to the diagnostic criteria based on the Oswestry disability index and dynamic features (△Timewalk: time until C7 sagittal vertical axis [C7SVA] reaches ≥ 20 cm after the start of walking) of sagittal imbalance. The paravertebral back muscles were analyzed and compared using T2-weighted axial imaging. We performed a statistically time-dependent spinopelvic sagittal parameter analysis of full standing lateral lumbar radiographs. Lumbar flexibility was analyzed using dynamic lateral lumbar radiography. Results: The patients were classified into the mild (△Timewalk ≥ 180 s, 35 patients), moderate (180 s > △Timewalk ≥ 30 s, 38 patients), and severe (△Timewalk < 30 s, 29 patients) groups. The back muscles in the severe group exhibited a significantly higher signal intensity (533.4 ± 237.5, p < 0.05) and larger area of fat infiltration (35.2 ± 5.4, p < 0.05) than those in the mild (223.8 ± 67.6/22.9 ± 11.9) and moderate groups (294.4 ± 214.7/21.6 ± 10.6). The analysis of lumbar flexibility revealed significantly lower values in the severe group (5.8° ± 2.5°, p < 0.05) than in the mild and moderate groups (14.2° ± 12.4° and 11.4° ± 8.7°, respectively). The severe group had significantly lower lumbar lordosis (LL, 25.1° ± 22.7°, p < 0.05) and Pelvic incidence-LL mismatch (PI-LL, 81.5° ± 26.6°, p < 0.001) than those of the mild (8.2° ± 16.3°/58.7° ± 18.8°) and moderate (14.3° ± 28.6°/66.8° ± 13.4°) groups. On receiver operating characteristic curve analysis, PI-LL was statistically significant, with an area under the curve of 0.810 (95% confidence interval) when the baseline was set at 75.3°. The severe group had more postoperative complications than the other groups. Conclusions: Our results suggest the following criteria for severe DSI: C7SVA > 20 cm within 30 s of walking or standing, a rigid lumbar curve < 10° on dynamic lateral radiographs, and a PI-LL mismatch > 75.3°. Level of evidence: 3. [ABSTRACT FROM AUTHOR]

The impact of scoliosis bracing combined with physiotherapeutic scoliosis-specific exercises (PSSE) on trunk muscle endurance in adolescents with idiopathic scoliosis is unknown. ScoliBrace®, a rigid, three-dimensional, over-corrective thoraco-lumbar-sacral orthosis (TLSO), and ScoliBalance®, a PSSE program, were used to treat adolescent idiopathic scoliosis (AIS) patients. A retrospective study of the trunk muscle endurance of 33 AIS patients who received ScoliBrace® and ScoliBalance® was conducted. The patients were treated with ScoliBrace® and an individualized ScoliBalance® program. Trunk extensor muscle endurance (TE) and abdominal muscle endurance (AE) tests were performed at initial assessment and then at averages of 6.6 and 24.4 weeks of treatment. The data were analyzed using the Wilcoxon signed-rank test, Stata version 15.1. The participants were aged 13.24 years (SD = 1.64) with a mean Cobb angle of 38.97° (SD = 9.49°). TE improved significantly (p < 0.001) at both short- and medium-term intervals using ScoliBalance® and ScoliBrace® in the AIS patients. AE also showed significant improvement between baseline and short-term follow-up, with non-significant improvement at medium-term follow-up. Overall, trunk muscle endurance showed improvement in the AIS patients using ScoliBrace® and ScoliBalance®. Future research is required to determine the individual and combined effects of each treatment. However, it seems likely that trunk muscle endurance will not deteriorate in AIS patients with this combined treatment. [ABSTRACT FROM AUTHOR]

The study aimed to investigate the impact of different levels of quercetagetin on the slaughter performance, organ index, meat quality, and meat nutrient composition in Ira rabbits. A total of 200 healthy rabbits, with an initial weight of (1 184.75±181.44) g at 35 days old, were randomly divided into five groups, with eight replicates in each group and five rabbits in each replicate. The control group was fed a basic diet, while the experimental groups were fed diets supplemented with 5, 25, 50, and 75 mg/kg of QG, respectively. The pre-trial period lasted for five days, and the formal experimental period lasted for 28 days. The results showed that there was no significant difference in the final weight of rabbits among the experimental groups compared to the control group ( P>0.05). Compared with the control group, there was a tendency to increase the half-eviscerated yield rate in the 50 mg/kg QG group ( P>0.05), and there was no differences on other indices of slaughter performance among the experimental groups ( P>0.05). Compared with the control group, the addition of 75 mg/kg QG increased the spleen index of rabbits ( P<0.05), and different doses of QG increased the kidney and thymus indices ( P<0.05). Adding 75 mg/kg QG reduced steaming loss compared to the control group ( P<0.05). Adding 25, 50, and 75 mg/kg QG increased the crude fat content in the back longissimus muscle of the rabbits ( P<0.05). The study indicates that the inclusion of QG in the diet promotes organ development, improves meat quality, and increases the crude fat content in rabbit meat. The suitable addition level of QG in the rabbit diet is 50-75 mg/kg. [ABSTRACT FROM AUTHOR]

Purpose: Intervertebral disc degeneration (IVDD), Modic changes, and fatty infiltration in the paraspinal muscles are possible causes of low back pain (LBP). Multifidus has been the most commonly blamed paraspinal muscle in the etiology of LBP. However, it contributes to 20% of the extensor moment on the lumbar spine. In the present study, we aimed to identify whether patients with LBP and asymptomatic subjects differed in terms of intervertebral discs, end‐plates, and fatty infiltration in their paraspinal muscles. Methods: Consecutive women and men, who visited the spine outpatient clinics with chronic LBP and had lumbar spine MRI for their LBP without leg pain were included. Asymptomatic subjects without LBP/leg pain for the last year were recruited. Modic changes, IVDD, and fatty infiltration in the paraspinal muscles were evaluated on lumbar spine magnetic resonance imagings of the patients with LBP and age‐, gender‐ and BMI‐matched asymptomatic controls. Results: Low back pain was closely associated with fatty infiltration in the paraspinal muscles at all lumbar levels whereas it had association with severe IVDD and Modic changes at lower lumbar levels. Multifidus at the lower lumbar levels was the fattiest paraspinal muscle in both asymptomatic subjects and patients with LBP. Patients with LBP had severe fatty infiltration in the erector spinae at the upper lumbar levels. Conclusion: Severe IVDD and Modic changes were more common at lower lumbar levels in patients with LBP. Both asymptomatic subjects and those with LBP had fatty multifidus at lower lumbar levels, whereas those with LBP had fatty infiltration in the erector spinae at upper lumbar levels. We suggest that fatty infiltration could have started in the multifidus. The erector spinae had greater contribution to the lumbar extension compared to the multifidus. Thus, LBP could develop when the quality of the erector spinae at the upper lumbar levels impairs due to fatty infiltration. [ABSTRACT FROM AUTHOR]

This study on occupational back-support exoskeletons performs a laboratory evaluation of realistic tasks with expert workers from the railway sector. Workers performed both a static task and a dynamic task, each involving manual material handling (MMH) and manipulating loads of 20 kg, in three conditions: without an exoskeleton, with a commercially available passive exoskeleton (Laevo v2.56), and with the StreamEXO, an active back-support exoskeleton developed by our institute. Two control strategies were defined, one for dynamic tasks and one for static tasks, with the latter determining the upper body's gravity compensation through the Model-based Gravity Compensation (MB-Grav) approach. This work presents a comparative assessment of the performance of active back support exoskeletons versus passive exoskeletons when trialled in relevant and realistic tasks. After a lab characterization of the MB-Grav strategy, the experimental assessment compared two back-support exoskeletons, one active and one passive. The results showed that while both devices were able to reduce back muscle activation, the benefits of the active device were triple those of the passive system regarding back muscle activation ( 26 % and 33 % against 9 % and 11 % , respectively), while the passive exoskeleton hindered trunk mobility more than the active mechanism. [ABSTRACT FROM AUTHOR]

Due to the economic differences of chili peppers at different maturity levels and the absence of differentiation of maturity in existing harvesting processes, it is crucial to accurately identify the maturity during harvesting for improving economic benefits. This paper investigated pepper maturity recognition models using hyperspectral technology to realize intelligent pepper harvesting with high accuracy and monitor maturity. Hyperspectral data (400–1000 nm) for field line peppers were collected, preprocessed using normalization, Savitzky-Golay convolutional smoothing, and standard normal variable transformation and subsequently used to train back propagation neural network (BP) and kernel based extreme learning machine (KELM) models. Principal component analysis (PCA) was used to reduce data dimensionality and identify characteristic spectral wavelengths for pepper maturity at 862.2, 676.9, 578.1, and 980.7 nm; and BP, PCA-BP, KELM, and PCA-KELM models were subsequently established. The precision for the KELM and PCA-KELM models (99.5% and 97.3%, respectively) was superior to the other two models; however, the PCA-KELM model used only four of the feature wavelengths as inputs, hence it required only 1/44 the data compared with the KELM model. Thus, the PCA-KELM model achieved high recognition accuracy and training speed, offering an effective method to discriminate pepper ripeness based on hyperspectral features. [ABSTRACT FROM AUTHOR]

Background: The barbell squat is an exercise used to strengthen the lower limbs, with implications for both performance in sports and improving movement during everyday tasks. Although the exercise is being trained across a variety of repetition ranges, the technical requirements may vary, affecting appropriate repetition range for specific training goals. Methods: A randomised within-subject design was used to compare kinematics and surface electromyography (EMG) in the lower extremities during different concentric phases (pre-, sticking- and post-sticking region) of the last repetition when performing squats at different repetition maximums (RMs). Thirteen strength-trained men (age: 23.6 ± 1.9 years; height: 181.1 ± 6.5 cm; body mass: 82.2 kg, 1RM: 122.8 ± 16.2, relative strength: 1.5 ± 0.2 x body mass in external load) performed a 1, 3, 6, and 10RM squat, in a randomised order. Results: The main findings were that barbell-, ankle-, knee- and hip kinematics were similar across different repetition ranges, except for a smaller trunk lean at 1RM in the pre-sticking region compared to other repetitions and in the sticking region compared to 10RM (p ≤ 0.04). Furthermore, 1RM revealed significantly higher EMG amplitude in the vastus lateralis, gastrocnemius and soleus in the sticking and post-sticking regions when compared to 10RM. It was concluded that 10RM may locally fatigue the vastus lateralis and plantar flexors, explaining the lower EMG amplitude. The observed differences indicate that requirements vary for completing the final repetition of the 10RM compared to the 1RM, an important aspect to consider in training to enhance 1RM strength. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to investigate the effect of blood flow restriction (BFR) combined with low-intensity resistance training (RT) on cardiovascular risk factors in obese individuals. Methods: Twenty-six male obese college students were recruited and randomly assigned to a control group (CON, n = 8), a low-intensity RT group (RT, n = 9), and a combined BFR training and low-intensity RT group (BFRT, n = 9). Results: The subjects in BFRT group showed significant reductions in body fat percentage and waist-to-hip ratio and a significant increase in lean mass and muscle mass; the peak torque, peak power, and endurance ratio of knee extensors and elbow flexors were significantly upregulated; the root mean square (RMS) for the medial femoral muscle, lateral femoral muscle and biceps significantly increased; the diastolic blood pressure (DBP) showed a significant decrease. The BFRT group also showed significant up-regulations in RMS of the difference between the adjacent R-R intervals (RMSSD), high-frequency power (HF) of parasympathetic modulatory capacity, the standard deviation of R-R intervals (SDNN) of overall heart rate variability (HRV) changes and lowfrequency power (LF) of predominantly sympathetic activity. In addition, glycated hemoglobin (HbA1C), insulin resistance index (HOMA-IR) and fasting blood glucose (FBG) were all significantly downregulated in BFRT group. In parallel, low-density lipoprotein (LDL-C) significantly reduced while highdensity lipoprotein (HDL-C) significantly increased in BFRT group. Conclusion: BFR combined with low-intensity RT training effectively improved body composition index, increased muscle mass, improved neuromuscular activation, enhanced muscle strength and endurance, which in turn improved abnormal glucolipid metabolism and enhanced cardiac autonomic regulation. [ABSTRACT FROM AUTHOR]

For the development of an effective and faster wound closure method, it is necessary to overcome current techniques' limitations. As compared to other methods, biodegradable staples provide superior mechanical properties, reduce scarring, and promote healing faster. Here, polylactic acid (PLA) and polyethylene glycol (PEG) composite staplers produced by solvent casting are presented as a suggestion for rapidly and easily closing wounds. The resulting samples were tested for mechanical properties, contact angle, and degradation properties over 21–90 days in the engineering phase. Selected formulations were moved to the biological phase for in vitro cytotoxicity by MTT assay and the in vivo biocompatibility assessment by transplantation of the samples into rats' back muscle. The tissue samples were collected and evaluated using hematoxylin and eosin and trichrome staining 1, 6, and 12 weeks after transplantation. When considering the maximum force tolerance range for PLA–PEG at around 20–58 N and comparing it with comparable commercial products, as well as their degradation rate and hydrophilicity, it was concluded that this combination maintains wound edges together. Cell viability tests demonstrated no cytotoxicity in the samples after 48 and 72 h. Morphological observations indicated some condensations of collagen fibers and no remarkable infiltration of inflammatory cells around the transplanted samples. In conclusion, the combination of PLA and PEG showed suitable mechanical properties, superior hydrophilicity, high biocompatibility and is suitable for medical staplers, and is innovative. [ABSTRACT FROM AUTHOR]

Purpose: Manual therapy is used as a conservative treatment for people with low back pain (LBP). The scale of the problem encourages the search for the most effective methods to assess of manual treatment. Therefore, the aim of the study was to investigate magnitude of changes in muscle endurance using the Biering-Sorensen test (BST) and to analyse balance in patients with LBP treated with ERS and FRS muscle energy techniques (MET). Methods: The study included fifteen men with LBP (mean age: 42 years) working as automotive assemblers. Endurance of the biceps femoris (BF), gluteus maximus (GM) and erector spinae (ES) muscles were analysed using sEMG during the BST. The level of experienced pain, degree of disability and postural stability were also examined. Results before and after a three-week treatment cycle using MET were compared. Results: The MET therapy resulted in a reduction in pain (p = 0.001), an improvement in the degree of disability (p < 0.001) and an increase in the duration of the BST (p < 0.001). After therapy, the values of the NMFs parameter indicating the degree of fatigue increased, i.e., ES muscle endurance increased, both right (p = 0.004) and left (p < 0.001). There was also a statistically significant decrease in the centre of pressure (COP) movement velocity in balance tests. Conclusions: The use of MET in patients with LBP increases muscle endurance, improves postural balance, and reduces pain levels on the VAS and disability levels according to the ODI. MET appears to be a good tool for preventing LBP. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Introduction: the relationship between the elasticity of the hamstring musculature and the joint range of the hip has been demonstrated; therefore, in the present study we have set ourselves the main objective of comparing the effectiveness of 3 stretching methods in gaining elasticity of this muscle: Static Stretching, Muscle Energy Technique and Global Postural Re-education. As a secondary objective, we considered the possible relationship between the shortening of this muscle and low back pain. Material and method: a prospective longitudinal single-blind randomized clinical study was conducted following the recommendations and criteria of the Consolidated Standards of the Reporting Trials criteria (CONSORT).The sampling was for convenience. 148 subjects aged 22.50 (21-24) were recruited for the study, all of them students of the Osteopathic Physiotherapy course of the Degree in Physiotherapy at the European University of Madrid. For the analysis of the results of each intervention, 4 variables were used: finger-floor test, seat and reach test, knee angle and straight leg raise. Results: the 3 stretching methods were equally effective in gaining elasticity of the hamstrings compared to the control group, finding no significant differences between them; Regarding the second objective, the results showed that the subjects with some episode of low back pain in the last year presented a greater shortening of the hamstrings in the straight leg raise test compared to the subjects without previous episodes of low back pain. Conclusion: the 3 stretching methods are effective in increasing the elasticity of the hamstring muscles and gaining hip ROM; the relationship between hamstring shortening and previous episodes of low back pain should be further investigated. [ABSTRACT FROM AUTHOR]

Objective: To evaluate using a back exoskeleton in a simulated sorting task in a static forward bent trunk posture on muscle activity, posture, and heart rate (HR). Background: Potentials of exoskeletons for reducing musculoskeletal demands in work tasks need to be clarified. Methods: Thirty-six healthy males performed the sorting task in 40°-forward bent static trunk posture for 90 seconds, in three trunk orientations, with and without exoskeleton. Muscle activity of the erector spinae (ES), biceps femoris (BF), trapezius descendens (TD), rectus abdominis (RA), vastus laterals (VL), and gastrocnemius medialis was recorded using surface electromyography normalized to a submaximal or maximal reference electrical activity (%RVE (reference voluntary electrical activity)/%MVE). Spine and lower limb postures were assessed by gravimetric position sensors, and HR by electrocardiography. Results: Using the exoskeleton resulted in decreased BF muscle activity [−8.12%RVE], and minor changes in ES [−1.29%MVE], RA [−0.28%RVE], VL [−0.49%RVE], and TD [+1.13%RVE] muscle activity. Hip and knee flexion increased [+8.1°; +6.7°]. Heart rate decreased by 2.1 bpm. Trunk orientation had an influence on BF muscle activity. Conclusion: Using the back exoskeleton in a short sorting task with static trunk posture mainly reduced hip extensor muscle activity and changed lower limb but not spine posture. Implications of using a back exoskeleton for workers' musculoskeletal health need further clarification. Application: The detected changes by using the Laevo® illustrate the need for further investigation prior to practical recommendations of using exoskeletons in the field. Investigating various work scenarios in different kind of workers and long-term applications would be important elements. [ABSTRACT FROM AUTHOR]

BACKGROUND: Sedentary work may lead to low back pain. In particular, a slumped sitting position may exacerbate low back pain because of tissue damage caused by excessive lumbar flexion and posterior pelvic tilting. Subjects with low back pain may have excessive changes in the lumbopelvic posture and back muscle activity in the sitting position. OBJECTIVE: The purpose of this study was to compare the effects of vibration-based biofeedback using a motion sensor belt and no biofeedback on multifidus (MF) muscle activity and pelvic tilt angle during typing. METHODS: Thirty subjects with low back pain accompanied by hip flexion limitation (15 each in the biofeedback and non-biofeedback groups) were enrolled. Electromyography was used to investigate MF muscle activity before and after typing for 30 min. Pelvic tilt was measured after typing in a sitting position for 30 min. Independent t-tests were used to compare MF muscle activity, and pelvic and second sacrum tilt angles, between the biofeedback and non-biofeedback groups. RESULTS: After typing for 30 min, changes in MF muscle activity (11.45% and - 7.19% for the biofeedback and nonbiofeedback groups, respectively) and pelvic and second sacrum tilt angles (3.15 ∘ and 4.12 ∘ for the biofeedback group and - 11.05 ∘ and - 18.16 ∘ for the non-biofeedback group, respectively) were significantly smaller in the biofeedback than non-biofeedback group (p < 0.05). CONCLUSION: Vibration-based biofeedback minimizes the reduction in MF muscle activity and changes in pelvic and second sacrum tilt angles during typing in individuals with low back pain accompanied by hip flexion limitation. [ABSTRACT FROM AUTHOR]

Purpose: Validated deep learning models represent a valuable option to perform large-scale research studies aiming to evaluate muscle quality and quantity of paravertebral lumbar muscles at the population level. This study aimed to assess lumbar spine muscle cross-sectional area (CSA) and fat infiltration (FI) in a large cohort of subjects with back disorders through a validated deep learning model. Methods: T2 axial MRI images of 4434 patients (n = 2609 females, n = 1825 males; mean age: 56.7 ± 16.8) with back disorders, such as fracture, spine surgery or herniation, were retrospectively collected from a clinical database and automatically segmented. CSA, expressed as the ratio between total muscle area (TMA) and the vertebral body area (VBA), and FI, in percentages, of psoas major, quadratus lumborum, erector spinae, and multifidus were analyzed as primary outcomes. Results: Male subjects had significantly higher CSA (6.8 ± 1.7 vs. 5.9 ± 1.5 TMA/VBA; p < 0.001) and lower FI (21.9 ± 8.3% vs. 15.0 ± 7.3%; p < 0.001) than females. Multifidus had more FI (27.2 ± 10.6%; p < 0.001) than erector spinae (22.2 ± 9.7%), quadratus lumborum (17.5 ± 7.0%) and psoas (13.7 ± 5.8%) whereas CSA was higher in erector spinae than other lumbar muscles. A high positive correlation between age and total FI was detected (rs = 0.73; p < 0.001) whereas a negligible negative correlation between total CSA and age was observed (rs = − 0.24; p < 0.001). Subjects with fractures had lower CSA and higher FI compared to those with herniations, surgery and with no clear pathological conditions. Conclusion: CSA and FI values of paravertebral muscles vary a lot in accordance with subjectsʼ sex, age and clinical conditions. Given also the large inter-muscle differences in CSA and FI, the choice of muscles needs to be considered with attention by spine surgeons or physiotherapists when investigating changes in lumbar muscle morphology in clinical practice. [ABSTRACT FROM AUTHOR]

Objectives: Investigate sex differences in age-related back extensor muscle degeneration using Dixon MRI and analyze the relationship between quantitative muscle parameters and back muscle strength in healthy adults. Methods: 105 healthy subjects underwent lumbar Dixon MRI. Fat fraction (FF), cross-sectional area (CSA), functional CSA (FCSA), and relative FCSA (RFCSA) of multifidus muscle (MF) and erector spinae (ES) were quantified. Back extension muscle strength was measured using an external fixation dynamometer. ANOVA with post hoc Tukey correction was used for age group comparisons. Partial and Spearman's correlation analyzed relationships between age, muscle parameters, and muscle strength. Results: MF and ES FF significantly increased with age in both genders (r = 0.55–0.85; p < 0.001). Muscle FF increased prominently for females (40–49 years, MF and 50–59 years, ES) and males (60–73 years, MF and ES). In females, total ES FCSA and RFCSA (r = − 0.42, − 0.37; p < 0.01) correlated with age. While in males, all MF and ES muscle size parameters, except total MF CSA, correlated with age (r = − 0.30 to − 0.58; p < 0.05). Back extension muscle strength correlated with mean FF, total CSA, and total FCAS for MF and ES individually (p < 0.001). The combined MF + ES FCSA correlation coefficient (r = 0.63) was higher than FF (r = − 0.51) and CSA (r = 0.59) (p < 0.001). Conclusions: Age-related back extensor muscle degeneration varies by muscle type and sex. FCSA has the highest association with back muscle strength compared to FF and CSA. Clinical relevance statement: The investigation of sex differences in age-related back extensor muscle degeneration utilizing Dixon imaging may hold significant implications for evaluating spine health and enabling earlier intervention. Muscles' FCSA could contribute to acquiring additional evidence for reflecting muscle function change. Key Points: • The multifidus muscle (MF) and erector spinae (ES) fat fraction (FF) increased with age at all lumbar disc levels in females and males. • Age-related changes in muscle morphological quantitative parameters of healthy adults were specific by muscle type and gender. • The muscle functional cross-sectional area (FCSA) measured by Dixon imaging may better monitor back extensor muscle strength changes than muscle FF and cross-sectional area (CSA). [ABSTRACT FROM AUTHOR]

Aim: The aim of this study was to examine balance, lumbar multifidus muscle thickness and cross-sectional area (CSA), pain, disability and kinesiophobia levels, and to compare these parameters in terms of gender in patients with lumbar spinal stenosis (LSS). Material and Methods: This cross-sectional study included 59 patients, 33 (55.9%) female and 26 (44.1%) male, diagnosed with LSS by magnetic resonance imaging (MRI). Low back and leg pains, dynamic and static balances, disability and kinesiophobia levels of patients with LSS were evaluated. Lumbar multifidus muscle thickness and total CSA were obtained from MRI images. Obtained data were compared according to gender. Results: Females had significantly more low back pain than males (p=0.043), in patients with LSS. Additionally, females with LSS had worse dynamic and static balances (p=0.005, and p=0.001, respectively) and higher levels of disability (p=0.001), and kinesiophobia (p=0.001). Females with LSS had less lumbar multifidus muscle thickness and CSA than males on both the right and left sides. Also, right multifidus muscle thickness correlated with both dynamic (r=-0.289; p=0.027) and static (r=0.349; p=0.007) balances. Significant correlations were detected between low back and leg pain with dynamic and static balances, disability, and kinesiophobia in patients with LSS. Conclusion: Females with LSS have higher levels of pain, disability, and kinesiophobia than males. Also, LSS affects females' balance functions more and causes further degeneration of the multifidus muscle. Therefore, gender differences should be examined during the clinical follow-up process in LSS. [ABSTRACT FROM AUTHOR]

Background: Repetitive shoulder movements during competitive training may cause changes in the strength of periarticular shoulder structures in preadolescent swimmers. Objective: To prospectively determine the effects of training on shoulder periarticular structures and muscle strength in preadolescent swimmers. Design: Prospective cohort study. Setting: Community‐based natatorium. Participants: Twenty‐four preadolescent swimmers aged 10–12 years. Interventions: Not applicable. Main Outcome Measures: Measurements were repeated in three periods as preseason, midseason, and postseason. Ultrasonographic measurements (supraspinatus tendon thickness, humeral head cartilage thickness, deltoid muscle thickness, and acromiohumeral distance) were performed using a portable device and a linear probe. Shoulder (flexion, extension, abduction, internal and external rotation) and back (serratus anterior, lower, and middle trapezius) isometric muscle strength were measured with a handheld dynamometer. Results: Supraspinatus tendon thickness and acromiohumeral distance were similar in all periods (all p >.05); however, deltoid muscle and humeral head cartilage thicknesses increased throughout the season (p =.002, p =.008, respectively). Likewise, whereas shoulder muscle strength increased (all p <.05), back muscle strength was similar in all periods (all p >.05). Conclusions: In preadolescent swimmers, acromiohumeral distance and supraspinatus tendon thickness seem to not change; but humeral head cartilage and deltoid muscle thicknesses as well as shoulder muscle strength increase throughout the season. [ABSTRACT FROM AUTHOR]

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. 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. 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. The present study showed that women with chronic LBP present higher muscle activation of the rectus abdominis in the sit-to-stand task. [ABSTRACT FROM AUTHOR]

Study Design: Cross-sectional study. Objectives: Our aim was to describe age-dependent changes of lumbar paraspinal muscle endurance and morphology in Chinese healthy population. We also explored the relationship between paraspinals endurance and morphology. Methods: A total of 181 participants from Chinese community population without chronic low back pain were included. The participants were divided into three groups: young (20-39 years old, n = 29), middle (40-59 years old, n = 93), and elderly (≥ 60 years old, n = 59). The Ito test was performed to evaluate the isometric endurance of paraspinal muscles. The total cross-sectional area (TCSA) and fat infiltration (FI) of multifidus (MF) and erector spinae (ES) were measured at L1-L5 levels on magnetic resonance imaging. Physical activity level was evaluated using the physical activity index and comorbidities were assessed by the modified 5-item frailty index. Results: The elderly group had a shorter performance time of endurance test than the young group and middle-aged group. Correlation analysis showed that age had a significant correlation with endurance test, the average MF TCSA, MF FI, ES TCSA and ES FI of L1-5. In addition, PAI had a significant correlation with endurance test and MF FI. In multiple linear regression analysis, paraspinals endurance was associated with MF FI, ES FI, physical activity level and comorbidities. Conclusion: Age-related decreases in paraspinals endurance and TCSA, and an increase in FI were revealed. Besides, paraspinal muscles FI, but not TCSA, was negatively associated with the endurance of paraspinals. [ABSTRACT FROM AUTHOR]

The need for a scientific approach in the creation and the selection of complex exercises for functional and the first stage of kyphosis from different initial positions by use of props and equipment is essential and indispensable. The importance of this study is great, having in mind the fact that the rate of bodily deformities is quite high and tends to increase steadily. Starting from the need for a scientific approach in the creation and the selection of complex exercises for the functional and the first stage of kyphosis that are present among the school population is more than necessary. The importance of interdisciplinary character of biomechanics and its subject of interest and research in this study is presented through application of a qualitative biomechanical analysis which is conducted from several aspects of complex exercises for kyphosis, functional stage and first degree of deformity. Among other things, qualitative biomechanical analysis enables registration of changes that occur in the spine at different periods of growth and development of children. In particular, the pathological changes of the postural status that hinder the manifestation of motor skills and habits in the course of the physical and health education, as well as among those children who are actively engaged in sports. The research includes 12 exercises for strength of the postural muscles from different initial positions by use of props and equipment (functional stage and the first degree of kyphosis). The exercises are analyzed by the method of qualitative biomechanical analysis, algorithm ALPROBI and then processed by factorization of the matrix of inter-similarity by use of the method of the main components by the software package SPSS28 From the obtained results from this study it could be stated that the application of the exercises: Torso lifting from kneeling position with elbows bent at 90 degrees .908, Torso lifting from chest lying .952, Stretching the back muscles with hands on the bar.905. and their more frequent application throughout the training process both on daily and weekly basis would bring to more benefits and efficacy. [ABSTRACT FROM AUTHOR]

This study is to determine how a lightweight active soft waist exoskeleton (ASWE) reduces the oxygen consumption and activity of lower back muscles of the wearer performing the repetitive lifting tasks. The heavy and frequent manual lifting operations are usually associated with an increased risk of injury in the industry. An ASWE is designed to assist workers' spine for lifting weights. The structural composition and operation principle were described for the ASWE. Twelve men were recruited in the experiments as the test subjects. Oxygen consumption and electromyography of the thoracic erector spinae (TES) at the T9 level and lumbar erector spinae (LES) at the L3 level were recorded during 90 lifts in 15 min. Subjects' discomfort and effectiveness evaluation were collected after lifting trials. The average value of oxygen consumption was decreased from form 15.9 ml/kg/min (Without-ASWE condition) to 13.7 ml/kg/min (With-ASWE condition). The increase in electromyography root mean square amplitude from the start until the end of the lifting trial was significantly lower when the ASWE was in use for the TES (162.79 vs. 82.08%) and the LES (122.48 vs. 83.87%). The use of the ASWE showed less oxygen consumption and back muscle contraction compared to the nonuse, which might reduce metabolic consumption or slow down the muscle fatigue level of the wearer's back across the lifting trial. Therefore, wearing the ASWE can reduce the discomfort of body parts, lumbar regions that exercise for a long time. [ABSTRACT FROM AUTHOR]

In vertebrates, insulin-like growth like factors (IGFs) play an important role in growth and other physiological processes. The GH-IGF axis is considered a valuable tool to monitor fish growth performance. Herein, we report the molecular characterization of igf-1, igf-2, and β-actin transcripts and relative expression of igf-1 and igf-2 in the liver and muscle tissue of cage-reared butter catfish, Ompok bimaculatus, in response to different stocking densities (T1, 15 fingerlings m−3; T2, 25 fingerlings m−3; and T3, 35 fingerlings m−3) over 180 days of culture duration. The length of the partial amplified transcript sequence of Obigf-1, Obigf-2, and Obβ-actin was 325, 438, and 924 bp, respectively. Phylogenetically, Obigf-1 and Obigf-2 were closely clustered with catfishes, viz., Clarias magur, Bagarius yarrelli, and Silurus asotus. The expression of igf-1 was significantly downregulated in the liver at higher densities after 120 days as biomass in the cages increased, while igf-2 expression did not change with the stocking densities over the culture period. Cortisol concentration was significantly elevated in T3 groups post 150 days of the culture period and correlated negatively with the expression of igf-1 (p < 0.05) and igf-2 (p > 0.05). Environmental parameters, pH, TDS, hardness, conductivity, and alkalinity showed a significant positive correlation with hepatic IGF expression. Our study indicates that the liver-derived igf-1 plays a more important role in the regulation of growth in response to culture density in the species studied, and thus, igf-1 can be used effectively as a biomarker for growth. Furthermore, this study will help in planning a proper harvest schedule and optimize the culture practices of O. bimaculatus in an open water cage system. [ABSTRACT FROM AUTHOR]

Background: It is a very rare form of ocular motility characterized by alternating strabismus and orthotropia. We report a patient with a 48-h cycle of esohypotropia associated with axial high myopia that resolved by Yokoyama procedure. Case presentation: A 43-year-old female patient who underwent left medial rectus muscle recession and lateral rectus muscle resection elsewhere due to highly myopic strabismus 2 years ago. The patient experienced a recurrence of left esohypotropia 12 months after undergoing surgery, exhibiting a 48-hour cycle. The cycle is one full day of esohypotropia and one day of orthotropia. The patient exhibited a case of high myopia in the left eye, characterized by a diopter measurement of -24.00DS and an eye axis measurement of 28.43 mm. Orbital CT showed supertemporal dislocation of the posterior portion of the elongated globe out from the muscle cone. Based on these observations, we performed Yokoyama procedure by uniting the muscle bellies of the superior rectus(SR) and lateral rectus (LR) muscles to restoring the dislocated globe back into the muscle cone. Conclusions: When cyclic strabismus is combined with axial high myopia, the Yokoyama procedure was effective and cycles are successfully terminated without overcorrection on no squint days. The purpose of this procedure is to put the dislocated globe back into its muscle cone by uniting the muscle bellies of the superior rectus and lateral rectus. [ABSTRACT FROM AUTHOR]

Background: Testing the association between trunk muscle endurance and chronic ankle instability (CAI) is very important to recognize risk factors related to CAI. This facilitates prevention of injury and management of the associated musculoskeletal deficits of CAI. Objective: to assess endurance of trunk muscles in females with CAI. Methods: This study consisted of 62 females, allocated into two equal groups of 31; the experimental group (A) included females with CAI and the healthy control (Group B) included healthy females. McGill core endurance tests (prone-bridge, right side-bridge, left side-bridge, trunk flexion and horizontal back extension) were administered to assess trunk muscle endurance. Results: Statistical analysis revealed no significant differences in trunk muscle endurance between the two tested groups (p > 0.05). Conclusions: Although, the results indicated higher values of trunk endurance in the CAI group compared with their healthy controls, no statistically significant differences were observed between the two groups. This denotes the compensatory mechanism that altered ankle-hip strategy. [ABSTRACT FROM AUTHOR]

Considering that serious hand function damage will greatly affect the daily life of patients, its recovery mainly depends on the regular inspection and manual training of medical staff, and medical monitoring based on bioelectric signals can largely replace manual re-examination as autonomous rehabilitation technology. So, for the rationality of feature selection and the diversity of classifier design in the gesture recognition process based on electromyography (EMG) signals, this paper proposes a hand medical monitoring system based on feature selection method of feature subset average recognition rate and optimal machine learning algorithm selection, which mainly depends on the prediction of hand movement. At the same time, since most experiments are conducted in different non-public proprietary databases, the comparison between various gesture recognition methods can only be analyzed to a certain extent. Therefore, this paper uses the DB1 dataset in the large publicly available NinaPro database and combines with presently well-known 11 time-domain (TD) features and 5 frequency domain (FD) features, then uses the support vector machine (SVM) classifier to comparative analysis total 136 feature combinations under various feature numbers. Under the premise of ensuring the overall recognition rate of electromyography gesture, this method will be able to reduce the number of features in feature set, according to the change of the average remove redundant features, and construct an optimal reduced EMG feature set. Finally, through the four common hand motion classifiers based on machine learning: SVM, back propagation neural network, linear discriminant analysis, and K-nearest neighbor, this paper tests and verifies the separability of the optimal reduced EMG feature set, and based on this, selects the optimal hand motion classifier to build the optimal hand motion recognition system, improve the hand medical monitoring system, and provide technical reference for the construction of real-time medical monitoring system. [ABSTRACT FROM AUTHOR]