Spinal Muscle Research Articles

Simulation Based Analysis and Design of Passive Back Exoskeleton for Squat Lifting

Abstract Back pain is the most common musculoskeletal disorder that manual material handling laborers face as they lift heavy objects. To overcome the back pain problem, an assistive device (Exoskeleton) can be worn during lifting. Through musculoskeletal simulation, this work investigates how the passive back exoskeleton affects the spinal muscle forces and spinal joint reaction loads. Such simulation findings can provide insights to improve the back exoskeleton design further. For this purpose, the passive exoskeleton is modeled as a set of elastic elements (springs), and dynamic analysis for a lifting cycle is done during a squat lifting task. Musculoskeletal simulations were carried out in OpenSim software utilizing the open-source OpenSim lifting full body model. The model is modified by adding an external spring that provides assistive forces like a passive exoskeleton. During the whole lifting cycle, the erector spine muscle is strained, so unloading the erector spine muscle is the primary goal of most back support exoskeletons. This work aims to identify optimal spring configurations and design parameters for a passive back exoskeleton to aid in squat lifting by varying spring parameters and through a formulation of a multi-objective optimization problem. The optimized back exoskeleton is expected to reduce compressive and shear forces on the L5S1 joint during lifting.

The Influence of Artificial Breast Volume Induction on Postural Stability, Postural Orientation, and Neuromuscular Control in Healthy Women: A Cross-Sectional Study

(1) Background: The percentage of breast augmentations has increased in recent years alongside the frequency of implant removals. Musculoskeletal and postural disorders are often overlooked during this removal process. Research indicates that excess anterior load from breast implants can disrupt postural control and potentially lead to short- or long-term musculoskeletal dysfunction. This study aims to evaluate the immediate changes in postural control after artificial breast augmentation in healthy female volunteers. (2) Methods: Spinal angles, the center of pressure (CoP), and electromyographic activity of the spinal muscles were recorded in the static position and during the functional reach test (FRT) without and with implants of different volumes (220 mL, 315 mL, and 365 mL). Subjective perceptions of effort, comfort, weight, and performance in the FRT were also assessed. (3) Results: Statistical differences were significant in the scapular elevator during the one-minute standing position (lower activation with the 220 mL implant compared to the control and 315 mL) and in the trapezius muscles during the FRT (lower activation in the upper trapezius in the 315 mL vs. control in the reach phase and 220 mL vs. control in the return phase and higher activation in the lower trapezius in the 315 and 365 mL vs. control in the reach phase). Additionally, significant differences were identified in the performance of the FRT and the associated subjective perceptions. (4) Conclusions: Breast implants with sizes of 220, 315, and 365 mL can alter scapular neuromuscular control, but these differences do not seem substantial enough to result in negative biomechanical effects in the short-term analysis.

The efficacy of treatment with the use of Tergumed 700 system in a group of males with low back pain (LBP)

The aim of the study was to evaluate the efficacy of treatment with the use of the Tergumed 700 system in a group of males with low back pain (LBP) syndrome based on the dynamics of changes in the isometric strength of the lumbar spine muscles and the imbalances thereof. Thirty-six males were examined, 19 in the study group (A) and 17 in the control group (B). Magnetic resonance imaging (MRI) of the lumbar spine was applied to assess the degree of degenerative changes. The isometric strength and imbalance of the lumbar spine muscles were tested using the Tergumed 700 system. In the study group (A), traditional Richardson’s core stabilization exercises and therapy with the Tergumed 700 system were performed. In the control group (B), only Richardson’s core stabilization exercises were conducted. The therapy lasted 6 weeks. The examination was performed four times: before the therapy, and after 2, 4, and 6 weeks following the therapy commencement. After six weeks, in the test group (A), the lumbar extensor muscle strength (p = 0.006), left-sided rotator muscle strength (p = 0.015), and right-sided rotator muscle strength (p = 0.001) improved. However, in the control group (B), significant improvement after the same period was found only in the lumbar extensor muscle strength (p = 0.042). As a result of the programmed treatment based on the patient’s current condition test, the lumbar back pain syndrome therapy using the Tergumed 700 system combined with central stabilization exercises according to Richardson was found to be most effective.

Effects of Spinal De-loading Exercise Program on Spinal Muscle Endurance, Working Posture, and Musculoskeletal Discomfort among University Bus Drivers

Objectives: Professional drivers have a significant prevalence of musculoskeletal issues such as LBP as a result of extended sitting and vibration exposure. The purpose of this study was to evaluate the effects of a spinal de-loading exercise program on spinal muscle endurance, working posture, and musculoskeletal discomfort among university bus drivers. Methods: 52 subjects who fulfilled the selection criteria were taken and divided into two groups. The experimental group (Group A, n=26) received a spinal de-loading exercise program and the control group (Group B, n=26) received conventional physiotherapy exercises. Each group participated in the intervention thrice a week for six weeks. Findings: Statistical analysis showed significant improvement in both the groups, however more so in the experimental group. Comparing Group A to Group B, notable gains were seen. Group A experienced a 45.8% decrease in discomfort, a 56% decrease in pain, and a 42.4% improvement in working posture. In Group A, the transverse abdominis and multifidus muscles' endurance improved by 58.5% and 42.8%, respectively. Compared to Group B, these improvements were noticeably better. Novelty: This is the first study to design and assess an exercise program for university bus drivers that explicitly targets spinal de-loading. Compared to traditional physiotherapy exercises, the program substantially improved working posture, spinal muscular endurance, and the reduction of musculoskeletal pain and discomfort. Keywords: Drivers, Pain, Endurance, Posture, Spine, Discomfort, bus driver, back pain, De­loading exercises

Novel biallelic nonsense mutation in IGHMBP2 gene linked to neuropathy (CMT2S): A comprehensive clinical, genetic and bioinformatic analysis of a Turkish patient with literature review.

Spinal muscular atrophy with respiratory distress type 1 (SMARD1) and Charcot-Marie-Tooth type 2S (CMT2S) typically present before age 10. Genetic factors account for up to 50% of neuropathies, which often display varied symptoms. Mutations in the IGHMBP2 gene are associated with both CMT2S and SMARD1, resulting in a rare clinical condition marked by axonal neuropathy, spinal muscular atrophy, respiratory distress, and muscle weakness. Detailed family histories and medical data were collected. Segregation analysis was performed using Sanger sequencing and whole exome sequencing. Additionally, a review of molecularly confirmed patients was conducted. Protein tertiary structures expressed in the IGHMBP2 gene were tested for topological and conformational changes using modeling programs and in-silico tools. We identified a novel homozygous nonsense mutation (c.2568_2569del p.Gly857Alafs*27) in a family with a member showing neuropathy. This report details the clinical and genetic findings of the affected individuals, including a Turkish patient with neuropathy, and compares them with literature cases. Understanding the clinical impact of the (c.2568_2569del p.Gly857Alafs*27) mutation will enhance our knowledge of IGHMBP2 gene defects role in neuropathy. This study aims to highlight this severe recessive disease caused by pathogenic IGHMBP2 gene mutations and to examine the mutation spectrum and phenotype differences.

Latent profile analysis of spinal deep muscle strength and physical fitness in elite Taekwondo athletes

In Taekwondo, core stability and physical fitness are vital for performance, with spinal deep muscles playing a key role. This study explored the relationship between spinal deep muscle strength and physical fitness in 104 adolescent Taekwondo athletes, using a cross-sectional design in a laboratory setting. Participants were classified into groups based on spinal muscle strength at various angles, measured with a Centaur 3D machine. Outcome measures included body composition (height, weight, BMI) and physical fitness (grip strength, back muscle strength, endurance, flexibility, balance, and leg strength). Latent profile analysis identified five profiles: G2 and G4 showed higher body weight and skeletal muscle mass, with G2 also having the highest grip, back, and leg strength. No significant relationship was found between spinal muscle strength and balance. The findings suggest spinal muscle strength and physical fitness do not always correlate, highlighting the need for further research to optimize training.

Effects of Core Stability Training on Lumbar Flexibility in Postpartum Females with Hyperlordosis: AQuasi-Experimental Study

Background: Lordosis is the natural curve of lumbar spine which is essential for proper posture and spinalalignment. When this angle increases then that is hyperlordosis & when it decreases called hypolordosis.Many postpartum women experience an increase in lumbar lordosis, which can cause discomfort, pain, andpostural imbalances, potentially leading to long-term musculature issues. Core stability exercises effectivelystrengthen the abdominal and spinal muscles, addressing these postural problems and enhancing overallstability, which is crucial for recovery and preventing future complications.Objective: The current study was designed to assess the effect of core stability training on lumbar flexibilityin hyperlordotic postpartum females. Methods: In this Quasi Experimental study, a Non-Probability-Convenience sampling technique was used tocollect the data. The total duration of treatment was 12 weeks. Pre-treatment Modified-Modified SchoberTest (MMST) value was measured before and after the treatment of twelve weeks to check the efficiency ofthe core stability exercises in hyperlordotic postpartum females. Data was analyzed on SPSS 25. Results: In this study, core stability training significantly decreased lumbar lordosis (p value = 0.000) withmean values of 8.21 ± 0.22 and 7.68 ± 0.37 for Pre-Exercise MMST(Mean ± SD) and Post-Exercise MMST(Mean ± SD) respectively. Conclusions: Core stability training is a good approach for correcting lumbar lordosis and back pain afterchildbirth. This means core stability exercises played an important role in correcting hyperlordosis and ingaining the spine's normal curvature hence alleviating symptoms.

Impact of the Abdominal Drawing-In Maneuver on Spinal Extensor Muscle Activity: A Randomized Controlled Double-Blind Trial Involving Individuals with Non-Specific Low Back Pain.

Non-specific low back pain (NSLBP) is a common musculoskeletal issue that can limit function and reduce the patient's quality of life. Enhancing spinal stabilizer muscle activity through targeted exercises may help improve spinal alignment and alleviate NSLBP symptoms. This study aimed to investigate whether incorporating the abdominal drawing-in maneuver (ADIM) into selected low back exercises influences the electromyographic (EMG) activity of key spinal extensor muscles. Forty participants with NSLBP (n = 29 female and n = 11 male; mean age = 21.42 ± 1.07 years; BMI = 20.65 ± 2.08 kg/m2; 80% right-side dominant) performed three exercises, prone trunk extension, superman, and unstable superman, with and without the ADIM. The EMG amplitudes of the iliocostalis lumborum pars lumborum (ICL), iliocostalis lumborum pars thoracis (ICT), and longissimus thoracis (LT) were measured. A cross-sectional observational study design was employed. Significant main effects were observed for both exercise types and the ADIM on the EMG amplitudes of the ICL, ICT, and LT (ICL: F1,14 = 82.69-114.23, p < 0.001, η2 ≥ 0.88; ICT: F1,14 = 100.69-117.13, p < 0.001, η2 ≥ 0.90; LT: F1,14 = 62.69-74.88, p < 0.001, η2 ≥ 0.81). Under ADIM conditions, the ICL activity decreased significantly (right ICL mean difference: 14.06-20.02; left ICL: 13.06-21.32; p < 0.001), while the ICT and LT activity increased (ICT mean difference: 6.45-8.89; LT: 9.37-12.13; p < 0.001). These changes were most pronounced during the unstable superman exercise (p < 0.01). Integrating the ADIM into specific low back exercises can differentially modulate spinal extensor muscle activity. In particular, the unstable superman exercise demonstrated the greatest changes in the EMG amplitudes. These findings support the inclusion of the ADIM in exercise programs aimed at improving spinal stability and may have implications for NSLBP management. Future research should examine the effects of the ADIM in populations with varying experience levels to enhance its generalizability and refine the clinical recommendations.

Targeted Motor Control Considering Sternal Position Improves Spinal Alignment in Pregnant Women at Risk for Preterm Birth with Low Back Pain.

Background: Lumbopelvic pain (LBP) is a prevalent condition during pregnancy, affecting a significant proportion of pregnant women. It arises from hormonal, biomechanical, and postural changes, often exacerbating discomfort and impairing quality of life. This study aimed to evaluate the effects of targeted motor control interventions focusing on sternal alignment on spinal alignment, pain, and muscle activity in pregnant women at risk of preterm birth. Methods: This pre-post quasi-experimental study included 32 pregnant women at 28-32 weeks of gestation, who were hospitalized due to the risk of preterm birth. Inclusion criteria required participants to have LBP lasting at least two weeks and the ability to walk and stand for 40 min. The intervention involved targeted motor control exercises designed to optimize sternal and sacral alignment. Spinal alignment, pain intensity, and muscle activity were measured pre- and post-intervention using the DIERS formetric system, numerical rating scale (NRS), and electromyography (EMG), respectively. Data were analyzed using Wilcoxon signed-rank tests. Results: Significant improvements were observed in spinal alignment parameters, including reductions in the sternal angle, sacral angle, cervical and lumbar lordosis depths, thoracic kyphosis angle, and pelvic tilt (p < 0.05). Pain intensity decreased significantly from a mean NRS score of 5.77 ± 1.42 in the relaxed posture to 2.54 ± 0.71 in the corrected posture (p < 0.05). Muscle activity of the rhomboid muscles increased in the corrected posture, correlating with improved thoracic kyphosis, while activity of the serratus anterior muscle showed reductions (p < 0.05). Conclusions: Targeted motor control focusing on sternal alignment effectively improved spinal alignment and reduced pain in pregnant women at risk of preterm birth with LBP. The intervention offers a safe, non-invasive, and practical approach to managing pregnancy-related musculoskeletal challenges. Future research should validate these findings in diverse populations and explore long-term effects and broader clinical applications.

Cerebrospinal Fluid Metabolomics of Pain in Patients with Spinal Muscle Atrophy.

Cerebrospinal Fluid Metabolomics of Pain in Patients with Spinal Muscle Atrophy.

Assessing the potential of hand grip strength as an indicator of spinal muscle size

In order to assess how well hand grip strength can predict spinal muscle size and to determine if scaling improves prediction Biobank data was acquired consisting of hand grip strength, age, height, body mass and abdominal magnetic resonance images for 150 age-matched male and female participants. The cross-sectional area of the multifidus and erector spinae was measured from the images at the L3/L4 level. Correlation strength and prediction errors were quantified for muscle size predicted from hand grip strength, age, height, and body mass. The effect of scaling muscle area by height and height squared was also determined. All variables correlated significantly with spine muscle size. The strongest correlator was hand grip strength (r = 0.61, p &lt; 0.05) with a prediction error of 678 mm2. The strength of the correlations was reduced when muscle areas were scaled. Hand grip strength can predict spine muscle size in male and female participants; however, the confidence intervals on the predicted values are larger than would be expected from measuring muscle size directly using imaging technologies. Scaling by height or height squared does not improve the ability of hand grip strength to predict muscle size.

Macrophages excite muscle spindles with glutamate to bolster locomotion

The stretch reflex is a fundamental component of the motor system that orchestrates the coordinated muscle contractions underlying movement. At the heart of this process lie the muscle spindles (MS), specialized receptors finely attuned to fluctuations in tension within intrafusal muscle fibres. The tension variation in the MS triggers a series of neuronal events including an initial depolarization of sensory type Ia afferents that subsequently causes the activation of motoneurons within the spinal cord1,2. This neuronal cascade culminates in the execution of muscle contraction, underscoring a presumed closed-loop mechanism between the musculoskeletal and nervous systems. By contrast, here we report the discovery of a new population of macrophages with exclusive molecular and functional signatures within the MS that express the machinery for synthesizing and releasing glutamate. Using mouse intersectional genetics with optogenetics and electrophysiology, we show that activation of MS macrophages (MSMP) drives proprioceptive sensory neuron firing on a millisecond timescale. MSMP activate spinal circuits, motor neurons and muscles by means of a glutamate-dependent mechanism that excites the MS. Furthermore, MSMP respond to neural and muscle activation by increasing the expression of glutaminase, enabling them to convert the uptaken glutamine released by myocytes during muscle contraction into glutamate. Selective silencing or depletion of MSMP in hindlimb muscles disrupted the modulation of the stretch reflex for force generation and sensory feedback correction, impairing locomotor strategies in mice. Our results have identified a new cellular component, the MSMP, that directly regulates neural activity and muscle contraction. The glutamate-mediated signalling of MSMP and their dynamic response to sensory cues introduce a new dimension to our understanding of sensation and motor action, potentially offering innovative therapeutic approaches in conditions that affect sensorimotor function.

Window entrapment trauma in cats: clinical, neurological and clinicopathological findings and outcome (70 cases).

Window entrapment in cats can lead to reduced blood flow to the spinal cord, muscles and nerves, resulting in ischaemic neuromyelomyopathy. The severity and duration of entrapment greatly influence clinical and neurological outcomes, as well as prognosis. The aim of the present retrospective multicentric study (2005-2022) was to describe clinical, neurological and selected clinicopathological findings, as well as the outcome of cats trapped in bottom-hung windows, presented to both first-opinion and referral-only clinics. The study included cats with detailed clinical and neurological evaluations at admission, along with at least one of the following biochemical parameters: creatine kinase (CK), aspartate transaminase (AST), alanine aminotransferase (ALT) activities, urea and/or creatinine. Clinical and neurological parameters evaluated in the study included rectal temperature, femoral pulse, gait, urinary bladder function, tail function and survival to discharge. Odds ratios (ORs) were calculated for survival and each clinical, neurological and biochemical variable. Of the 70 cats that met the inclusion criteria, only seven (10%) died or were euthanased during hospitalisation. Nevertheless, with the available data, we found evidence of an association between clinical and neurological status and survival, with tail function being the strongest association. Cats lacking tail sensation, motor function and/or tonus were more likely to die than cats with normal tail function or only mild abnormalities (OR = 24). Similarly, cats with severe hypothermia or an absent femoral pulse were less likely to survive (OR = 12.75 and 7.5, respectively). In this sample (with a relatively low number of deaths), we did not find evidence of an association between CK, AST and ALT activity with survival. However, the only two cats with severe increases in creatinine died. Assessment of gait, urinary bladder function, femoral pulse, rectal temperature and particularly tail function is promising for predicting outcomes in cats with window entrapment trauma.

New Training Frontiers in Golf Considerations from a neurosurgical perspective

Background: Golf, a sport gaining popularity globally, poses unique risks to musculoskeletal health, particularly among older players. The repetitive nature of the golf swing and inadequate athletic preparation often lead to injuries, especially in the spine, shoulders, and elbows. This study explores the biomechanics of golf and evaluates innovative training methodologies to mitigate injury risks and enhance performance. Materials and Methodology: The study integrates insights from sports science, neurosurgical assessments, and physical therapy to analyze common injury mechanisms in golf. Data from a comprehensive literature review, including clinical case studies and injury prevalence surveys, were combined with biomechanical evaluations. Modern training approaches such as the Gyrotonic Expansion System, MFT Proprioceptive Tables, and elastic resistance training were examined for their efficacy in improving flexibility, strength, and injury prevention. Results: Findings highlight that injury risk peaks during the downswing and impact phases of the golf swing due to high muscular loads and sudden force application. Older golfers exhibit higher injury rates, attributed to age-related physiological changes such as reduced spinal flexibility and muscle strength. Implementing structured training programs significantly reduced injury incidences and enhanced golfers' biomechanical efficiency. Techniques like Gyrotonic and Body Blade improved spinal mobility and neuromuscular control, while MFT tables optimized balance and coordination. Conclusion: Proper athletic preparation tailored to golfers' needs, incorporating multidisciplinary evaluations and advanced training systems, can mitigate injury risks and prolong active participation in the sport. Integrating these strategies, particularly for older players, enhances both safety and performance, underscoring the need for wider adoption in golf training protocols.

Bobath And Pilates Therapy On Sitting And Standing Balance In Children With Cerebral Palsy

Cerebral Palsy is the most common neurological disorder in children that affects movement and posture due to damage to the brain which controls motor skills, causing balance problems when sitting and standing. This balance is affected by the strength of the erector spine and abdominal muscles that straighten and control the trunk. If low trunk muscle tone causes problems with balance and mobility so that the child has difficulty sitting, playing in a sitting position, functional hand movements such as eating and activities of daily living. This research is an experiment with a pre test – post one group design which aims to analyze the effectiveness of bobath and pilates therapy on sitting and standing balance in children with cerebral palsy. A total of 17 children with cerebral palsy were given bobath and pilates therapy for 16 weeks, with a dose of: 1 time/day, 3 times a week with a treatment time of 45 minutes for each child. The research subjects were children with cerebral palsy with the following criteria: 1-year old, unbalanced sitting and standing. It will be carried out from February to June 2023. Sitting balance is measured with a sitting level scale and standing balance with a pediatric balance scale. The research subjects consisted of 13 men (76.47%) and 4 women (23.53%) with the GMFCS categories being III and IV. The average age of research subjects: 36.5758 ± 15.02504. The results of statistical tests with Wilcoxon obtained a value of p = 0.001 at the sitting level of the scale and p = 0.002 on the pediatric balance scale. Conclusion: Bobath and pilates therapy are effective in increasing the value of the sitting level of the scale and the pediatric balance scale in children with cerebral palsy.

Combination of Adult Mesenchymal Stem Cell Therapy and Immunomodulation with Dimethyl Fumarate Following Spinal Cord Ventral Root Repair.

Spinal cord injury results in significant motor and sensory loss. In the experimental ventral root avulsion (VRA) model, the ventral (motor) roots are disconnected from the spinal cord surface, disrupting contact between spinal motoneurons and muscle fibers. Axotomized motoneurons typically degenerate within two to three weeks after avulsion, the situation being exacerbated by an increased glial response and chronic inflammation. Nevertheless, root reimplantation has been observed to stimulate regenerative potential in some motoneurons, serving as a model for CNS/PNS regeneration. We hypothesized that a combination of neuroprotective and immunomodulatory therapies is capable of enhancing regenerative responses following nerve root injury and repair. A heterologous fibrin biopolymer (HFB) was used for surgical repair; dimethyl fumarate (DMF) was used for neuroprotection and immunomodulation; and adipose tissue-derived mesenchymal stem cells (AT-MSCs) were used as a source of trophic factors and cytokines that may further enhance neuronal survival. Thus, adult female Lewis rats underwent unilateral VRA of the L4-L6 roots, followed by reimplantation with HFB, AT-MSCs transplantation, and daily DMF treatment for four weeks, with a 12-week postoperative survival period. An evaluation of the results focused on light microscopy, qRT-PCR, and the Catwalk motor function recovery system. Data were analyzed using one-way or two-way ANOVA (p < 0.05). The results indicate that the combined therapy resulted in a reduced glial response and a 70% improvement in behavioral motor recovery. Overall, the data support the potential of combined regenerative approaches after spinal cord root injury.

Neuroticism Overestimated? Neuroticism Versus Hypertonia, Pain and Rehabilitation Outcomes in Post-Spinal Cord Injury Patients Rehabilitated Conventionally and with Robotic-Assisted Gait Training.

The aim of the present study was to analyse the association between neuroticism (one of the Big Five personality traits) and the most common secondary sensorimotor complications occurring in patients after spinal cord injury (SCI), i.e., muscle spasticity (hypertonia) and pain, and to investigate the associations between neuroticism and the effects of conventional rehabilitation (dynamic parapodium) and those using robotic-assisted gait training (RAGT) in this group of patients. In addition, the association of neuroticism with self-efficacy, personal beliefs about pain control, and adopted coping strategies among SCI patients was analysed. These data can be used as a reference for designing effective forms of therapy and support dedicated to this group of patients. Quantitative analysis included 110 patients after SCI. The participants were divided by simple randomisation into a rehabilitation group with RAGT and a rehabilitation group with dynamic parapodium therapy (DPT). The following survey instruments were used for data collection: Revised NEO Personality Inventory (NEO-PI-R); Ashworth Scale; the Spinal Cord Independence Measure III (SCIM III); the Walking Index for Spinal Cord Injury II (WISCI-II); the American Spinal Injury Association Impairment Scale (AIS); the Pain Coping Strategies Questionnaire-CSQ; and the Beliefs about Pain Control Questionnaire-BPCQ. analyses showed a positive association between neuroticism and spastic tension (rho = 0.39; p < 0.001). the study showed that a high level of neuroticism correlates with a higher level of spasticity, but no such correlation was observed for pain. Additionally, the study did not show a significant correlation between neuroticism and rehabilitation outcome depending on the rehabilitation modality (RAGT vs. DPT). The results underline the importance of carrying out a psychological diagnosis of patients to provide therapeutic support in the rehabilitation process.

Thoracolumbar spine muscle size and composition changes in long-duration space missions

Muscle atrophy occurs with extended exposure to microgravity. This study quantified the overall muscle size, lean muscle area and fat infiltration changes pre- to post-flight that occur in the thoracic and lumbar spine with long-duration spaceflight. Pre- and post-flight magnetic resonance imaging (MRI) scans were obtained from 9 crewmembers on long-duration (≥6 months) International Space Station (ISS) missions. Muscle size was measured by the cross-sectional area (CSA) and lean muscle tissue by the functional cross-sectional area (FCSA). Muscle-fat infiltration (MFI) was measured by the mean pixel intensities of the MRI in fat and water phases. A mixed model with random subject effect was used to analyze pre- to post-flight changes. Significant decreases were seen in the quadratus lumborum muscle size (-1.8 ± 0.6% per month, p = 0.002) and lean muscle tissue content in the paraspinal muscles (-0.7 ± 0.2% per month, p ≤ 0.001). Fat infiltration increased significantly in the transversospinalis (+4.1 ± 1.0% per month, p ≤ 0.01) muscle. Treadmill exercise had a tendency to reduce fat content in the paraspinal and quadratus lumborum muscles, while counteracting muscle build-up only in the paraspinal muscles. Cycle ergometer exercise suggested benefits for the psoas muscle. Resistance training appeared to benefit lean muscle mass of most thoracolumbar muscles. Our findings highlight the need for countermeasures to prevent muscle atrophy and detrimental effects in muscle composition during long-duration spaceflight.

Learning curve and long-term outcomes of minimally invasive correction and fusion for adolescent idiopathic scoliosis.

Retrospective analysis. This study sought to report the long-term outcomes of patients that underwent minimally invasive surgery (MIS) correction for Adolescent Idiopathic Scoliosis (AIS) in terms of radiographic, clinical, and patient-reported outcomes. Furthermore, we examined the learning curve of MIS technique over the course of 13years. Both MIS and open techniques are used to surgically address AIS. MIS techniques are purported to preserve the midline spinal musculature and to decrease estimated blood loss (EBL) and hospital length of stay (LOS). Data were collected at a single tertiary care center of all consecutive AIS patients undergoing deformity surgery from January 2008 to October 2021. Demographic, clinical, and radiographic data were collected at various intervals. Descriptive and inferential analyses were conducted. 70 AIS patients were included in the study. Mean patient age was 16.2years of which 95.7% were female, with a mean BMI of 21.7. The majority of the patients were Lenke type 1A (60%) followed by Lenke 1B (18.6%) with mean preop Cobb angle as 52.2°. The mean follow-up was approximately 6years with 35.7% of our cohort meeting the long-term follow-up landmark (> 5years, 2-11). The mean number of spinal levels treated was 9.3 with mean ASA score of 1.7. Overall, mean EBL was 151cc with mean OR of 308min. The mean LOS was 3.94days with postop Day 1 as the initiation of ambulation. Overall, the percent correction at the last visit was significantly greater than preop (Cobb: 77.6%, p < 0.05). Mean loss of correction on follow-ups was less than 5º. The overall revision rate was 2.9%. At 2years postop, 98.6% (69/70) of the patients achieved fusion with 100% (24/24) at 5years, and 96% (24/25) beyond the 5-year mark. Surgeon's technical proficiency in performing MIS for the treatment of AIS corrections was achieved after 23 cases. Based on our cohort's 2-11year follow-up data, we conclude that MIS provides an effective treatment option for AIS reconstruction. Our study indicates that MIS can achieve adequate deformity correction and positive long-term clinical outcomes as indicated by Cobb angle, VAS, ODI, and SRS-22r scores during follow-ups. If the individual goals of AIS surgery can be achieved, consideration should be given to less-invasive techniques. IV.

Effect of Shoulder Flexion Range of Motion and Trunk Muscle Activity on Lumbar Lordosis in the Streamlined Posture in Healthy Young Men.

Objective This study aimed to compare the lumbar spine, pelvic alignment, and trunk muscle activity in healthy participants with and without shoulder flexion restriction in a streamlined posture. Methods The lumbar lordosis angle, pelvic anteversion angle, and trunk muscle activity were measured in 31 young, healthy men in the resting standing position. The streamlined (SL) posture and correlation analysis were performed. Multiple regression analysis was performed to analyze variables that affect the lumbar lordosis angle in the SL posture. Results Correlation analysis revealed that the lumbar lordosis angle in the SL posture had a significant negative correlation with the muscle activity of the internal oblique/transversus abdominis muscle (IO/TrA) during the SL posture (r=-0.37, p<0.045). Multiple regression analysis revealed that lumbar lordosis angle in the SL posture was associated with lumbar lordosis angle in the upright position (β=0.46), IO/TrA activity (β=-0.37), shoulder joint flexion range of motion (β=-0.37), and longissimus dorsi muscle activity during the SL posture (β=-0.28), with a Durbin-Watson statistic adjusted coefficient of determination R2 of 0.67 (p<0.001). Conclusion The lumbar lordosis angle in the SL posture was likely to be high when the range of motion of shoulder joint flexion was small, the activity of the longissimus dorsi muscle in the SL posture was high, and the activity of the IO/TrA was low. This suggests that limited shoulder flexion causes excessive lumbar lordosis, which may be a mechanism of low back pain in swimmers.