Back Muscle Research Articles

Use of Pilates Training in Back Pain and Musculoskeletal Disorders: A Literature Review

Introduction: Pilates is a type of physical exercise invented by Joseph Pilates. They aim to have a positive effect on the body and mind. Pilates can be performed with special machines called reformers or without any additional equipment, simply on a mat. The exercises focus on strengthening the deep muscles, including the core, which can help in the treatment of patients with back pain. In addition, they have a positive effect on maintaining correct posture and fluidity of movement. Due to the above characteristics, Pilates can be one of the pillars of therapy for back pain, musculoskeletal pain, including that associated with rheumatological diseases. Aim of the study: The aim of this publication is to review the available literature to answer the question of whether Pilates training is a suitable intervention in back pain and musculoskeletal disorders and to compare its effects with other interventions (e.g. the Mckenzie Method or extensiona based exercises). Material and methods: Review of the literature available on PubMed and Google Scholar database searching by the keywords: pilates, pilates and pain, pilates and back pain, pilates and spine, fibromyalgia, pilates and neck pain. Conclusions: Pilates is a training method that can be implemented in the treatment of many ailments. These exercises have produced very good results in the treatment of back pain, neck pain, muscle and joint pain in the course of rheumatic diseases. Studies indicate that Pilates has a beneficial effect on the rehabilitation process, sometimes exceeding the effects of traditional physiotherapy. In addition to its very good therapeutic effect, Pilates is characterised by a good safety profile. Even the pregnant population can benefit from the exercises. It is likely that both mat and equipment exercises have benefits, but research on this issue is required. Given the promising results, further research should be conducted into the effects of Pilates in various pain conditions.

Associations of back muscle endurance with occupational back muscle activity and spinal loading among subsistence farmers and office workers in Rwanda.

Over the course of the physical activity transition, machines have largely replaced skeletal muscle as the source of work for locomotion and other forms of occupational physical activity in industrial environments. To better characterize this transition and its effect on back muscles and the spine, we tested to what extent typical occupational activities of rural subsistence farmers demand higher magnitudes and increased variability of back muscle activity and spinal loading compared to occupational activities of urban office workers in Rwanda, and whether these differences were associated with back muscle endurance, the dominant risk factor for back pain. Using electromyography, inertial measurement units, and OpenSim musculoskeletal modeling, we measured back muscle activity and spinal loading continuously while participants performed occupational activities for one hour. We measured back muscle endurance using electromyography median frequency analysis. During occupational work, subsistence farmers activate their back muscles and load their spines at 390% higher magnitudes and with 193% greater variability than office workers. Partial correlations accounting for body mass show magnitude and variability response variables are positively associated with back muscle endurance (R = 0.39-0.90 [P < 0.001-0.210] and R = 0.54-0.72 [P = 0.007-0.071], respectively). Body mass is negatively correlated with back muscle endurance (R = -0.60, P = 0.031), suggesting higher back muscle endurance may be also partly attributable to having lower body mass. Because higher back muscle endurance is a major factor that prevents back pain, these results reinforce evidence that under-activating back muscles and under-loading spines at work increases vulnerability to back pain and may be an evolutionary mismatch. As sedentary occupations become more common, there is a need to study the extent to which occupational and leisure time physical activities that increase back muscle endurance helps prevent back pain.

Enhancing understanding: Back muscle strength and individual flexibility impact on the flexion-relaxation phenomenon in the lumbar erector spinae

The flexion-relaxation phenomenon (FRP) refers to the deactivation of back muscles during deep forward trunk bending. This study examined the effects of back muscle strength, individual flexibility, and trunk angle on FRP in the back muscles. Forty male participants were classified into four groups according to toe-touch flexibility and back muscle strength. Lumbar erector spinae (LES) activity and the lumbosacral angle (LSA) were measured at incremental trunk flexion angles (0°–90°, with increments of 15°) to analyze FRP. Results indicated significant effects of back muscle strength, flexibility, and trunk angle on LES activity (all p < 0.001). Flexibility (p < 0.05) and trunk angle (p < 0.001) also influenced LSA. Additionally, an interaction between flexibility and trunk angle impacted LES activation (p < 0.001). Flexibility mainly determined FRP onset, while back muscle strength influenced efforts during moderate trunk flexion (30°–60°). These findings indicate that differences in lower back load among individuals with varying back muscle strengths become apparent even at relatively small trunk flexion angles (approximately 30°). When prolonged static trunk flexion in workplace settings places considerable strain on the lower back, we recommend utilizing toe-touch flexibility and back muscle strength assessments as practical screening tools for identifying early and subtle indicators of the FRP in workers.

Motion Tape Strain During Trunk Muscle Engagement in Young, Healthy Participants

Background: Motion Tape (MT) is a low-profile, disposable, self-adhesive wearable sensor that measures skin strain. Preliminary studies have validated MT for measuring lower back movement. However, further analysis is needed to determine if MT can be used to measure lower back muscle engagement. The purpose of this study was to measure differences in MT strain between conditions in which the lower back muscles were relaxed versus maximally activated. Methods: Ten participants without low back pain were tested. A matrix of six MTs was placed on the lower back, and strain data were captured under a series of conditions. The first condition was a baseline trial, in which participants lay prone and the muscles of the lower back were relaxed. The subsequent trials were maximum voluntary isometric contractions (MVICs), in which participants did not move, but resisted the examiner force in extension or rotational directions to maximally engage their lower back muscles. The mean MT strain was calculated for each condition. A repeated measures ANOVA was conducted to analyze the effects of conditions (baseline, extension, right rotation, and left rotation) and MT position (1–6) on the MT strain. Post hoc analyses were conducted for significant effects from the overall analysis. Results: The results of the ANOVA revealed a significant main effect of condition (p &lt; 0.001) and a significant interaction effect of sensor and condition (p = 0.01). There were significant differences in MT strain between the baseline condition and the extension and rotation MVIC conditions, respectively, for sensors 4, 5, and 6 (p = 0.01–0.04). The largest differences in MT strain were observed between baseline and rotation conditions for sensors 4, 5, and 6. Conclusions: MT can capture maximal lower back muscle engagement while the trunk remains in a stationary position. Lower sensors are better able to capture muscle engagement than upper sensors. Furthermore, MT captured muscle engagement during rotation conditions better than during extension.

Effectiveness of Schroth Therapy in Improving Self-Perception, Body Image, and Quality of Life in Patients with Adolescent Idiopathic Scoliosis: A Systematic Review

Introduction: Adolescent idiopathic scoliosis is a structural spinal deformity that not only affects physical health but also has significant psychosocial consequences, such as body image disturbances, reduced self-perception, and diminished quality of life (QoL). Schroth therapy, a physiotherapeutic intervention designed to address scoliosis through three-dimensional exercises, has shown promise in managing these outcomes. This systematic review aims to evaluate the effectiveness of Schroth therapy in improving self-perception, body image, and QoL in adolescents with AIS. Methods: A systematic review was conducted following PRISMA guidelines. Studies published between 2015 and 2024 were identified using PubMed, Embase, and Cochrane Library databases. Randomised controlled trials (RCTs) involving adolescents aged 10-18 years with AIS, receiving Schroth therapy as the primary intervention, were included. Outcomes measured were self-perception, body image, and QoL, assessed using tools like the SRS-22/23 and WRVAS. The risk of bias was evaluated using the Pedro scale. Results: Six studies, with sample sizes ranging from 28 to 60 participants, were included in this review. The Schroth therapy group demonstrated significant improvements in self-perception, as measured by the Walter Reed Visual Assessment Scale (WRVAS), with a between-group difference of 6.5 points (95% CI: 3.2 to 9.9, p &lt; 0.01, F = 169.5) reported by Buyukturan et al. (2024). Additionally, improvements in the self-image domain of the SRS-22 questionnaire were observed, with a mean change of 0.149 (95% CI: 0.001 to 0.297, p = 0.049) noted by Zhang et al. (2024). In terms of quality of life (QoL), one study by Kocaman et al. (2021) found a 15% increase in overall SRS-22 scores (p = 0.02), while the combined SE + ASSE group exhibited significant improvements in QoL compared to the SE-only group (p = 0.019) as shown by Khaledi et al. (2024). While other measures, such as Cobb angle and back muscle endurance, showed significant results, the focus of this review highlights the notable benefits of Schroth therapy on self-perception and QoL. Conclusions: Schroth therapy appears effective in enhancing self-perception, body image, and quality of life in adolescents with AIS. While current evidence supports its psychosocial benefits, further long-term studies with larger sample sizes and more sensitive assessment tools are needed to validate these findings.

Effects of a soft back exoskeleton on lower lumbar spine loads during manual materials handling: a musculoskeletal modelling study

The aim of this study was to append a passive soft back exoskeleton to a validated musculoskeletal model and assess its effectiveness in reducing lumbar loads. Fifteen participants lifted a box, with and without wearing a CORFOR® exoskeleton. A full body OpenSim model was used to estimate lumbar joint moments and reaction forces, as well as low back muscles forces. Wearing the exoskeleton reduced the peak flexion moment, muscles forces, as well as peak compressive and shear forces. This musculoskeletal modelling study shows that wearing the exoskeleton may reduce lumbar spine loads and may contribute to prevent low back disorders.

Development of a spinopelvic complex finite element model for quantitative analysis of the biomechanical response of patients with degenerative spondylolisthesis.

Research on degenerative spondylolisthesis (DS) has focused primarily on the biomechanical responses of pathological segments, with few studies involving muscle modelling in simulated analysis, leading to an emphasis on the back muscles in physical therapy, neglecting the ventral muscles. The purpose of this study was to quantitatively analyse the biomechanical response of the spinopelvic complex and surrounding muscle groups in DS patients using integrative modelling. The findings may aid in the development of more comprehensive rehabilitation strategies for DS patients. Two new finite element spinopelvic complex models with detailed muscles for normal spine and DS spine (L4 forwards slippage) modelling were established and validated at multiple levels. Then, the spinopelvic position parameters including peak stress of the lumbar isthmic-cortical bone, intervertebral discs, and facet joints; peak strain of the ligaments; peak force of the muscles; and percentage difference in the range of motion were analysed and compared under flexion-extension (F-E), lateral bending (LB), and axial rotation (AR) loading conditions between the two models. Compared with the normal spine model, the DS spine model exhibited greater stress and strain in adjacent biological tissues. Stress at the L4/5 disc and facet joints under AR and LB conditions was approximately 6.6 times greater in the DS spine model than in the normal model, the posterior longitudinal ligament peak strain in the normal model was 1/10 of that in the DS model, and more high-stress areas were found in the DS model, with stress notably transferring forwards. Additionally, compared with the normal spine model, the DS model exhibited greater muscle tensile forces in the lumbosacral muscle groups during F-E and LB motions. The psoas muscle in the DS model was subjected to 23.2% greater tensile force than that in the normal model. These findings indicated that L4 anterior slippage and changes in lumbosacral-pelvic alignment affect the biomechanical response of muscles. In summary, the present work demonstrated a certain level of accuracy and validity of our models as well as the differences between the models. Alterations in spondylolisthesis and the accompanying overall imbalance in the spinopelvic complex result in increased loading response levels of the functional spinal units in DS patients, creating a vicious cycle that exacerbates the imbalance in the lumbosacral region. Therefore, clinicians are encouraged to propose specific exercises for the ventral muscles, such as the psoas group, to address spinopelvic imbalance and halt the progression of DS.

DYNAMICS OF ANTHROPOMETRIC AND PHYSICAL MARKERS OF SARCOPENIC OBESITY IN ELDERLY PERSONS WITH OSTEOARTHRITIS OF THE HIP IN THE PROCESS OF PHYSICAL THERAPY

Purpose: to determine the effect of a physical therapy program on anthropometric and physical indicators of elderly people with osteoarthritis of the hip, which occurs against the background of sarcopenic obesity. Material. 68 elderly people with osteoarthritis of the hip and sarcopenic obesity and 36 of their healthy peers (control group) were examined. Representatives of the comparison group (33 persons) corrected the signs of osteoarthritis according to the clinical guideline "Osteoarthrosis". Representatives of the main group (35 persons) were engaged in a physical therapy program for six months. Its goal was: reduction of pain and discomfort in the hip; improvement of the amplitude of movements in the hip, joints of the lower limbs, spine; optimization of general mobility and motor stereotype; decrease of body weight; facilitating activities of daily living; improvement of geriatric status. The physical therapy was implemented in rehabilitation center and in the form of telerehabilitation. It included kinesitherapy, Proprioceptive Neuromuscular Facilitation of the lower limbs and lower back; massage, kinesiological taping of the hip, thigh and lower back muscles; a course of shock wave therapy of the hip, nutritional correction, education of patients and their family members. The effectiveness of the program was evaluated by the dynamics of anthropometry (mass, body mass index, waist and hip circumferences and their ratio), body composition (fat content, muscle tissue, visceral fat), sarcopenia markers (hand dynamometry, Short Physical Performance Battery). Results. Application of the physical therapy program led to a decrease in body weight in patients of the main group: in men by 5.4 kg, in women by 4.51 kg, p&lt;0.05. Corresponding changes occurred in body mass index, and the women of the main group reached the level of overweight. The dynamics of the abdominal nature of obesity also changed: the decrease in waist circumference in men was 8.3 cm, in women - 5.9 cm, which had a favorable effect on the ratio of waist and hip circumferences. A decrease in the severity of the signs of sarcopenia in main group persons was confirmed by the results of a statistically significant increase in the content of muscle tissue both in men (from 22.17±1.30% to 28.12±1.09%) and in women (from 19, 01±1.20% to 23.44±1.15%). The content of visceral fat in the subjects of the main group decreased by almost 25%. The content of adipose tissue in the whole body decreased in men from 42.29±1.73% to 34.50±1.22%, in women – from 46.53±1.19% to 40.57±1.57%. The increase in hand dynamometry results in women was from 13.48±1.14 kg to 17.22±0.56 kg, in men - from 19.80±1.07 kg to 26.15±1.01 kg. The complex nature of the physical therapy program contributed to the improvement of performance of all Short Physical Performance Battery subtests in the main group, and the improvement of its total score was 35.5% (from 6.49±0.53 points to 10.07±0.44 points, p&lt;0, 05). Patients of the comparison group, who underwent rehabilitation according to the standard program for the correction of osteoarthritis, did not show improvement in the studied indicators of anthropometry and markers of sarcopenia (p&gt;0.05). Conclusions. Elderly patients with osteoarthritis of the hip and sarcopenic obesity require the development of physical therapy programs taking into account and correcting the specifics of each condition, which will increase the overall effectiveness of rehabilitation measures.

Dynamics of cardio-muscular networks in exercise and fatigue.

A fundamental question in cardiovascular and muscle physiology is how the heart operates in synchrony with distinct muscles to regulate homeostasis, enable movement and adapt to exercise demands and fatigue. Here we investigate how autonomic regulation of cardiac function synchronizes and integrates as a network with the activity of distinct muscles during exercise. Further, weestablish how the network of cardio-muscular interactions reorganizes with fatigue. Thirty healthy young adults performed two body weight squat tests until exhaustion. Simultaneous recordings were taken of a 3-lead electrocardiogram (EKG) along with electromyography (EMG) signals from the left and right vastus lateralis, and left and right erector spinae. We first obtained instantaneous heart rate (HR) derived from the EKG signal and decomposed the EMG recordings in 10 frequency bands (F1-F10). We next quantified pair-wise coupling (cross-correlation) between the time series for HR and all EMG spectral power frequency bands in each leg and back muscle. We uncovered the first profiles of cardio-muscular network interactions, which depend on the role muscles play during exercise and muscle fibre histochemical characteristics. Additionally, we observed a significant decline in the degree of cardio-muscular coupling with fatigue, characterized by complex transitions from synchronous to asynchronous behaviour across a range of timescales. The network approach we utilized introduces new avenues for the development of novel network-based markers, with the potential to characterize multilevel cardio-muscular interactions to assess global health, levels of fatigue, fitness status or the effectiveness of cardiovascular and muscle injury rehabilitation programmes. KEY POINTS: The heart operates in synchrony with muscles to regulate homeostasis, enable movement, and adapt to exercise demands and fatigue. However, the precise mechanisms regulating cardio-muscular coupling remain unknown. This study introduces a pioneering approach to assess cardio-muscular network interactions by examining the synchronization of cardiac function with muscle activity during exercise and fatigue. We uncover the first profiles of cardio-muscular interactions characterized by specific hierarchical organization of link strength. We observe a significant decline in the degree of cardio-muscular coupling with fatigue, marked by complex transitions from synchronous to asynchronous behaviour. This network approach offers new network-based markers to characterize multilevel cardio-muscular interactions to assess global health, levels of fatigue, fitness status or the effectiveness of cardiovascular and muscle injury rehabilitation programmes.

Changes in Skeletal Muscle Atrophy over Time in a Rat Model of Adenine-Induced Chronic Kidney Disease

This study evaluated changes over time in skeletal muscle atrophy, expressions of skeletal muscle anabolic and catabolic genes, and mitochondrial activity by skeletal muscle type in an adenine-induced chronic kidney disease (CKD) model. A CKD model was successfully established by feeding male Wistar rats a 0.75% adenine diet for 4 weeks starting at 8 weeks of age. Control and CKD groups were sacrificed at 12 and 20 weeks of age. The back muscles were analyzed histologically, and succinate dehydrogenase (SDH) staining was performed to evaluate mitochondrial activity. Gene expressions of myogenic determination gene number 1 and myogenin as indicators of muscle anabolism, atrogin-1 and muscle RING-finger protein-1 (MuRF1) as indicators of muscle catabolism, and peroxisome proliferator-activated receptor-γ coactivator-1-α as a marker of mitochondrial biogenesis were assessed. Type I and type II muscle cross-sectional areas (CSAs) were decreased at 12 weeks, but type I muscle CSA was recovered at 20 weeks. SDH staining was lower in CKD than in control rats at 12 weeks, but no significant difference was observed at 20 weeks. Increased expressions of myogenin, atrogin-1, and MuRF-1 were observed only at 12 weeks, but no differences were observed at 20 weeks. The adenine-induced CKD rat model appears to show changes in muscle atrophy over time.

Right-left sEMG burst synchronization of the lumbar erector spinae muscles of seated violin players

Burst-like activation of postural muscles has been previously described and plays a crucial role in elucidating the strategies for postural control adopted by the central nervous system (CNS). A spatio-temporal descriptor of surface electromyographic (sEMG) bursts (STB) is proposed and applied to statistically quantify the burst-like activity of the right and left (R-L) lumbar erector spinae muscle of nine seated violinists playing for two hours. The STB signal is the number of pixels of the high density sEMG (HDsEMG) maps simultaneously showing sEMG amplitude above a given threshold. Burst activity was present in all nine subjects. Four of them met four stringent criteria allowing analysis of frequency, duration, and synchronization between the R-L bursts after 0, 15, 30, 60, 120 min of playing. Mean square coherence between STBs of the two muscles was > 0.75 within ⁓1 Hz bandwidth between 2.2 Hz and 4.5 Hz depending on subject. Non-parametric statistics was applied to compare, in time and space, the R-L features of the bursts. The mean STB width was significantly associated primarily to side and secondarily to time and ranged from 100 to 250 ms. The right STB signals led the left (p < 0.02) by 0 - 160 ms.The inverted pendulum composed by the upper body of a seated violinist is controlled in an intermittent way. The erector spinae of the selected subjects were active, on average, for less than 50% of the time. These findings demonstrate a CNS strategy of intermittent back muscle activation presumably aimed to reducing fatigue during hours of playing in seated violinists.

Dynamic Modelling of the Spine for the Estimation of Vertebral Joint Torques using Gordon’s Method

World Health Organization (WHO) recognised musculoskeletal disorder (MSD) as the main contributor to disability worldwide, with low back pain as the major disorder globally. The occupational disorder normally occurs during lifting. The weight of the load and manual handling tasks during lifting has an impact on the spine and joint torque. The purpose of this study is to propose a dynamic model of the spine that can estimate the vertebral joint torques. This study is a bimodal approach that consists of the experimental and theoretical parts. Ten healthy UniMAP students (10 males) participated in this study. The subjects were required to lift a 3kg weight plate for kinematics and EMG data collection. Retro-reflective markers were attached to the subject body, and then, the data was collected and stored in QTM software. Kinematic data was processed using C-Motion Visual3D. Eight Trigno Wireless Sensors were attached on the back muscles (left and right erector spinae, latissimus dorsi, external oblique and internal oblique). The EMG data were stored in EMG Acquisition software and subsequently, were processed using EMG Analysis software. Gordon’s method was used to develop a mathematical model of the spine. The model comprises of five kinematic chains which connected three lumbar, two thoracic and one cervical. The model calculated the value of joint torque on flexion/extension movement using Matlab and Microsoft Excel. When calculated on L5, the model gives an estimation within 0 – 30 kgm2s-2. The model was further used to estimate value of L3, L1, MAI and T2. The estimate average value of joint torque at L3 is within 5 – 25 kgm2s-2, MAI is within 0 – 6 kgm2s-2 and T2 is within 0 – 1 kgm2s-2. The average RMS values show the highest muscle activity on the right internal oblique muscle (1519 µV), followed by the right external oblique (1166 µV) and left external oblique (418 µV). The results obtained gives an insight on the value of joint torque that have been applied by the spine and the most activated back muscles during lifting.

Surface electromyographic analysis of the bilateral abdomen and back muscle during selected yoga posture

Sedentary lifestyles lead to postural deformities, Lower Back Pain(LBP) and Colorectal cancer(CRC). Practicing Yoga attains definite strength in muscles by activating muscle fibers. The Yoga poses analyzed are often used in strengthening and stability programs for the abdomen and back muscles. ObjectiveTo determine the potential use of Dolphin pose and Dolphin plank in specific strengthening endurance and rehabilitation programs via sEMG analysis in the selected bilateral abdomen and lower back muscles. MethodsSurface electromyographic analysis was conducted on bilateral muscles, including the Rectus Abdominis(RA), External oblique(EO), Internal oblique(IO), and Erector Spinae(ES), resulting in Dolphin pose(DS), Dolphin plank(DP), and High plank(HP). Data were expressed by Root Mean Square(RMS) of each bilateral muscle during each Pose normalized as 100% of maximum voluntary isometric contraction(MVIC). ResultsDolphin plank(DP) generated a very high-level muscle activation than 100% MVIC in all bilateral muscles, and there was a significant main effect of Pose e (p < 0.001). Erector spinae generated more activation in the Dolphin pose (p < 0.05) than in the HP and DS. No significant difference between bilateral activity differences in DP and DS. There was a significant difference between RRA and LRA (p < 0.001) and RIO and LIO (p < 0.0001). ConclusionFindings have suggested that the Dolphin plank could be used for abdomen strengthening, performance enhancement, and rehabilitation programs. Dolphin pose may benefit lower back stability by providing endurance to the Erector spinae muscle. So, this yoga pose can be incorporated into the yoga training module for addressing lower back pain(LBP) caused by longer sitting in a sedentary lifestyle.

Sea Bass (Dicentrarchus labrax) Tail-Beat Frequency Measurement Using Implanted Bioimpedance Sensing

Estimating tailbeat frequency (TBF) is a crucial component of fish swimming kinematics and performance, particularly because it provides information about energetics and behavioral responses to environmental cues. The most commonly used technique for TBF estimation is based on accelerometers. This paper proposes a novel approach using bioimpedance technology. This is the first time bioimpedance has been measured in a freely moving animal. This was made possible by implanting a flexible electrode in the back muscle of seabasses and having them in a swimming tunnel. The experiment first demonstrates that it is possible to measure bioimpedance in an immersed fish despite the high conductivity of seawater. An agreement analysis was then performed to compare a video-based reference measurement of TBF with the newly proposed approach. Several bioimpedance settings, such as the configuration and the extracted electrical parameters, were considered. Data analysis highlights that a 4-point setup for modulus impedance measurement at frequencies over 10 kHz provides the best agreement (r &gt; 0.98 and CCC &gt; 0.97) with the video-based approach. These results attest to the significant benefits of integrating bioimpedance sensors in biologgers, especially considering the complementary parameters that can be extracted from bioimpedance measurements, such as length, weight, condition index, and fat content.

The influence of feed additive “Activo” on the content of total lipids and their classes profile in liver and skeletal muscles of pigs

With an increase in meat consumption the requirements for its quality also rise. As pork is the second most popular meat in the world, producers of this product are trying to improve its quality. The purpose of our research was to determine the effect of the feed additive “Activo”, containing essential oils of cinnamon, rosemary and oregano, and chili pepper extract, on the total lipids content and their individual class profile in liver and skeletal muscles of pigs. The study was conducted on pigs of the large white breed, weighing 70 kg, divided on two groups, according to the piglets-analogues principle, which then were divided into control and experimental groups. Pigs of both groups received standard feed (SF) intended for this age group. Pigs of the experimental group received the feed additive “Activo” in an amount of 0.1 kg/t of feed in addition to SF. The duration period of experiment was 40 days. Samples of liver, longissimus dorsi, and latissimus dorsi muscle tissues were used as material for the study. The total lipid content was determined using gravimetric method, and individual lipid profile using thin-layer chromatography on silica gel plates. The study has shown that the total lipid content in the liver, long and broad back muscles of pigs of the experimental group was 1.66 and 1.95 (P≤0.001) and 1.26 (P≤0.05) times higher, respectively, than in animals of the control group. The relative cholesterol esters content in the liver lipids of the experimental group pigs was 1.9 (P≤0.001) times higher than in the control group. Instead, in the latissimus dorsi muscle, a lower content of triacylglycerols and a higher content of unesterified fatty acids (P≤0.05), esterified cholesterol (P≤0.05), and especially phospholipids (P≤0.001) were admitted. It was determined significant decrease of unesterified cholesterol content in the latissimus dorsi muscle (P≤0.001) and increase of phospholipids content (P≤0.001) under the effect of the researched feed additive.

Evaluation of the reliability of measuring lower back muscles cross-sectional area based on manual segmentation within multi-level MRI images

IntroductionManual segmentation of paraspinal muscle cross-sectional area (CSA) is widely used to assess related health disorders. This study aimed to evaluate the reliability of this segmentation process for each paraspinal region of interest across the three intervertebral levels commonly used for segmentation (L3/4, L4/5, and L5/S1). MethodsAxial-T2-weighted MRI images for 238 patients were divided among five raters (47 ± 1 cases each). To conduct the intra-rater reliability study, the CSA of each paraspinal lumber muscle (psoas major (PM), multifidus (MF), and erector spinae (ES)) and the intervertebral disc (ID) were manually segmented twice on all targeted levels before being assessed for each region per rater. The Inter-rater reliability was determined by comparing the results of different readers who segmented the same dataset. The Intraclass Correlation (ICC) and Coefficient-of-Variation percentage (CV%) were reported for each analysis. ResultsLow intra- and inter-rater variability (CV%<11) was found for each reader in each region and intervertebral level. The inter-rater reliability was excellent (ICC>0.9) for the PM, ID, and ES at L3/4. However, it was very good for MF at all levels and ES at L4/5, L5/S1 (ICC range: 0.82–0.88) affected by the fat-infiltration nature of the ES and MF muscles, their proximity to each other, and their smaller size (correlation between muscle size and ICC = 0.6, P < 0.01). The ID segmentation has the lowest CV (<3 %) and excellent ICC (>0.93). ConclusionManual paraspinal muscle segmentation using axial-T2-weighted MRI is reliable at all commonly segmented intervertebral levels. However, the reliability level can be degraded by the presence of high-fat infiltrate, unclear muscle boundaries, and muscle size. Implications for practiceFollowing consistent guidelines can help improve segmentation results. The IDs can be used as reliable internal references.

Are Ratings of Perceived Exertion during Endurance Tasks of Predictive Value? Findings in Trunk Muscles Require Special Attention.

Background: Subjective rating scales of perceived exertion are often used to quantify effort levels during various endurance exercises, particularly submaximal tasks. The aim of the current study was to determine whether predictive conclusions can be drawn from perceived exertion levels surveyed at the start of defined submaximal endurance tasks. Methods: In this study, healthy participants performed a 10-min endurance task at 50% of their upper body weight, targeting either the back muscles (n = 47, 24 women) or abdominal muscles (n = 32, 17 women). At the end of each minute, participants were asked to rate their perceived exertion (RPE) using the 14-points Borg Scale. Based on their initial and final RPE levels, and for each muscle group separately, participants were divided into subgroups reflecting low (good start/good end) and high (bad start/bad end) strain levels. These values were then compared over the duration of the exercise. Comparisons of RPE levels between subgroups were made using the Mann-Whitney U-test for independent samples, with Bonferroni-Holm correction to account for multiple comparisons. Results: Overall, strain levels increased throughout the duration of the exercise. For the abdominal muscles, the difference between the two RPE groups remained constant over time: participants with good start/end ratings consistently showed different strain levels from those with bad start/end ratings, regardless of whether the grouping was based on initial or final exertion levels. In contrast, for the back muscles, the initial grouping showed a crossover in strain values: by the end of the task, participants in the good start group tended to report higher strain than those in the bad start group. No differences were found in initial RPE values when the grouping was based on final exertion levels. Conclusions: For endurance tasks involving the abdominal muscles, initial strain levels have strong predictive value, whereas this is not the case for the back muscles. Because back muscles are frequently loaded, continuous monitoring of RPE levels is necessary to prevent unexpected task failure, as initial RPE values are not predictive. In contrast, RPE values of 11 or higher on the 14-points Borg scale predict complete exhaustion or even premature task failure with high certainty for abdominal muscle exercises, while lower RPE levels indicate that exercise intensity can be increased.

Postural Risks in Dental Practice: An Assessment of Musculoskeletal Health.

In recent years, Romania's stomatology private practice sector has seen substantial growth, with many dentists fully committing to building and expanding their own practices, often funded by their personal income. This study aimed to explore how various postures affect the muscle groups of dentists (380), particularly focusing on identifying positions that may jeopardize their musculoskeletal health. A group of dentists effectively participated in this study (10), adhering to their regular work routines while wearing wearable sensors on their backs to monitor posture and activity. The data gathered from these sensors were analyzed using the RULA (rapid upper-limb assessment) and REBA (rapid entire-body assessment) tools. The findings indicated that the head and shoulder movements during dental procedures involved considerable and repetitive angular shifts, which could strain the neck and back muscles and heighten the risk of musculoskeletal problems. Additionally, the standing postures adopted by the dentists were associated with an increased risk of postural issues and greater overall fatigue. Extended periods of trunk and head tilting were also identified as contributing factors to posture-related challenges.

Does proprioceptive reweighting contribute to reactive balance strategies during slip-like perturbations? a proof-of-concept in healthy adults

Falls commonly occur during walking, particularly when struggling to respond to unexpected perturbations. Proprioception plays a significant role in detecting body destabilization even before reactions to perturbations are required. This study investigates the contribution of proprioceptive reweighting strategies to reactive balance during walking. This cross-sectional, proof-of-concept study included fifteen healthy adults (18–40 years). Ankle and back muscle vibrators disrupted proprioceptive input in stance, allowing calculation of the proprioceptive reweighting index. Walk-slip perturbations were then administered on an ActiveStep treadmill. A linear regression model assessed the significance of proprioceptive reweighting in predicting post-slip stability (margin of stability). Participants shifted from an ankle-steered to a central-steered proprioceptive strategy on a foam surface with closed eyes (Difference = 15.70 % (SD=37.87), 95 %CI [0.41, 30.99], p = 0.045). The regression model explained 22.7 % of the variance in pre-touchdown margin of stability, with proprioceptive reweighting on foam significantly contributing to post-perturbation postural control (p < 0.001). Proprioceptive reweighting provides a moderate explanation for the mechanisms of reactive balance, highlighting that the key to effective balance recovery strategies may lie in the person’s ability to both detect and respond to imbalances. Further research should explore if these proprioceptive strategies are a matter of directional control and if responses differ in older adults.

Correlation of Vertebral Bone Quality and Paraspinal Muscle Changes With Adjacent Segment Degeneration After Transforaminal Lumbar Interbody Fusion Operation

To investigate the correlation of vertebral bone quality (VBQ) and paraspinal muscle changes with adjacent segment degeneration (ASD) after transforaminal lumbar interbody fusion (TLIF) through a retrospective analysis of patients who have undergone TLIF for lumbar degenerative diseases (LDD). A total of 98 patients who underwent TLIF surgical treatment for LDD between January 2016 and December 2022 at Shenzhen People's Hospital were selected. Well-established follow-up imaging data were available for all subjects who were divided into two groups, the ASD group (n=43) and the non-ASD (N-ASD) group (n=55), according to whether they met the ASD evaluation criteria. Data on the basic characteristics of the patients in both groups were collected, and the relevant parameters, including VBQ and the total cross-sectional area (TCSA) and the functional cross-sectional area (FCSA) of psoas major (PM), erector spinae (ES), and multifidus (MF), were measured by magnetic resonance imaging of the lumbar spine performed preoperatively and at the last follow-up. Then, the relative fat infiltration (RFI) was calculated from the above metrics accordingly. Logistic regression analysis was conducted to investigate the risk factors for ASD. The incidence of ASD was 43.9% (n=43) at the final follow-up. The mean follow-up time was (27.23±4.15) months. The age, body mass index (BMI), preoperative bone mineral density (BMD), preoperative VBQ, ΔRFIPM, and ΔRFIES+MF showed significant differences between the ASD and N-ASD groups (P<0.05). According to the results of the logistic regression analysis, BMI (odds ratio [OR]=1.450, 95% confidence interval [CI]: 1.081-1.945, P=0.013), preoperative VBQ (OR=6.191, 95% CI: 1.692-22.657, P=0.006), and ΔRFIES+MF (OR=1.117, 95% CI: 1.007-1.238, P=0.037) were independent risk factors for ASD. The incidence of postoperative ASD in patients who have undergone TLIF for LDD was found to be associated with higher BMI, preoperative VBQ, and increased postoperative relative fat infiltration of the ES and MF muscles. Consequently, it is advisable to prioritize the intraoperative protection of the paraspinal muscles during TLIF. In the postoperative period, it is essential to strengthen exercises of the lower back muscles and to optimize bone mass and weight management, which is conducive to reducing the risk of ASD in the postoperative period.