Back Muscle Research Articles

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 < 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.

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<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<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>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

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

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.

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.

Effects of Dance Music on Motor Skills and Balance in Children: An Observational Cohort Study.

During the COVID-19 pandemic, children in Japan were restricted from sports and outdoor activities. Regular physical activity is essential for healthy growth and development in children, with recommendations advocating for activities such as strength training. However, the long-term effects of the restrictions have not been fully investigated. This study aimed to evaluate the effectiveness of an "exercise class", specifically a dance program, designed to improve motor function in elementary school children affected by the coronavirus disease 2019 (COVID-19) pandemic, which may have compromised their motor function. The dance program was developed by a sports science teacher, a professional dancer, and a physical therapist, and it was evaluated in a community-based participatory study. Trained dance instructors conducted one-hour dance sessions in a medical center, held once a week for two months from June to August 2023. A physical therapist and dance instructors led the elementary school children. Outcome measures included grip strength, lower extremity muscle strength, back muscle strength, dynamic balance function during movement, physical activity time, and body fat percentages. Descriptive statistics were used for analysis. Twenty-four children aged 6-9 years participated in the exercise class over a two-month period. Improvement was observed in grip strength, lower extremity muscle strength, and dynamic balance function during movement. However, physical activity time, body fat percentages, and back muscle strength did not change. The results indicated a significant improvement in motor skills. Dance is an inexpensive program that elementary school children can enjoy while improving their motor skills.

Age-related breakdown in networks of inter-muscular coordination.

Assessing inter-muscular coordination in older adults is crucial, as it directly impacts an individual's ability for independent functioning, injury prevention, and active engagement in daily activities. However, the precise mechanisms by which distinct muscle fiber types synchronize their activity across muscles to generate coordinated movements in older adults remain unknown. Our objective is to investigate how distinct muscle groups dynamically synchronize with each other in young and older adults during exercise. Thirty-five young adults and nine older adults performed one bodyweight squat set until exhaustion. Simultaneous surface electromyography (sEMG) recordings were taken from the left and right vastus lateralis, and left and right erector spinae. To quantify inter-muscular coordination, we first obtained ten time series of sEMG band power for each muscle, representing the dynamics of different muscle fiber types. Next, we calculated the bivariate equal-time Pearson's cross-correlation for each pair of sEMG band power time series across all leg and back muscles. The main results show (i) an overall reduction in the degree of inter-muscular coordination, and (ii) increased stratification of the inter-muscular network in older adults compared to young adults. These findings suggest that as individuals age, the global inter-muscular network becomes less flexible and adaptable, hindering its ability to reorganize effectively in response to fatigue or other stimuli. This network approach opens new avenues for developing novel network-based markers to characterize multilevel inter-muscular interactions, which can help target functional deficits and potentially reduce the risk of falls and neuro-muscular injuries in older adults.

Effects of time-dependent acupuncture on back muscle endurance in women with chronic nonspecific low back pain: A randomized crossover trial.

Chronic nonspecific low back pain (CNLBP) is a leading cause of disability and remains a major burden for many public health systems. Acupuncture is a nonpharmacological treatment for CNLBP that can be effective in improving low back pain; nevertheless, its effect on improving back muscle endurance in patients with CNLBP and its duration of effect have not been studied. The goal of this study was to assess the impact of acupuncture on lower back muscle activity in CNLBP patients. This was a single-blind, randomized, crossover experimental study. Thirty female patients were randomized into Group A (15 patients) or Group B (15 patients). Patients in Group A were assigned to receive real acupuncture (RA) in the first phase and sham acupuncture (SA) in the second phase, while those in Group B received SA first and then RA, with a 1-week washout period between phases. Two-way repeated ANOVA was used to evaluate the effect of group and time on isokinetic parameters, Surface electromyography (sEMG) data, and blood data. Significant interaction effects were identified between group * time on the isokinetic parameters of the lumbar extensor muscles, sEMG values of the erector spinae, blood lactate levels, and blood ammonia levels (all p< 0.05). Compared with those of the SA group, the isokinetic parameters of the lumbar extensor muscles, sEMG values of the erector spinae, blood lactate levels, and blood ammonia levels of the RA group were significantly different (all p< 0.05). RA improves lumbar extensor endurance in patients with CNLBP and lasts approximately 9 minutes. RA can improve blood circulation to reduce blood lactic acid and blood ammonia produced during exercise.

Musculoskeletal models determine the effect of a soft active exosuit on muscle activations and forces during lifting and lowering tasks

Exosuits have the potential to mitigate musculoskeletal stress and prevent back injuries during industrial tasks. This study aimed to 1) validate the implementation of a soft active exosuit into a musculoskeletal model of the spine by comparing model predicted muscle activations versus corresponding surface EMG measurements, and 2) evaluate the effect of the exosuit on peak back and hip muscle forces. Fourteen healthy participants performed squat and stoop lift and lower tasks with boxes of 6 and 10 kg, with and without wearing a 2.7 kg soft active exosuit. Participant-specific musculoskeletal models, which included the exosuit, were created in OpenSim. Model validation focused on the back and hip extensors, where temporal agreement between EMG and model estimated muscle activity was generally strong to excellent (average cross-correlation coefficients ranging from 0.84 to 0.98). Root mean square errors of muscle activity (0.05–0.10) were similar with and without the exosuit, and compared well to prior model validation studies without the exosuit (average root mean square errors ranging from 0.05 to 0.19). In terms of performance, the exosuit reduced the estimated peak erector spinae forces during lifting and lowering phases across all lifting tasks but reduced peak hip extensor muscles forces only in a squat lift task of 10 kg. These reductions in total peak muscle forces were approximately 1.7–4.2 times greater than the corresponding exosuit assistance force, which were 146 ± 19 N and 102 ± 14 N at the times of peak erector spinae forces in lifting and lowering, respectively. Overall, the results support the hypothesis that exosuits reduce soft tissue loading, and thereby potentially reduce fatigue and injury risk during manual materials handling tasks. Incorporating exosuits into musculoskeletal models is a valid approach to understand the impact of exosuit assistance on muscle activity and forces.

Comparison of Isometric and Dynamic Bridging Exercises on Low Back Muscle Oxygenation.

Bridging exercises are commonly performed by people with low back pain (LBP). However, the effect of the contraction mode in a bridging exercise on the hemodynamics of the low back muscle has not been investigated in people with and without LBP. The objective of this study was to assess the effect of the mode of bridging exercise on oxygenation of the low back muscle. A near-infrared spectroscopy was used to measure hemodynamic responses of the erector spinae between isometric and dynamic bridging exercises in 16 healthy participants. The results demonstrated that during exercise, the isometric bridging exercise significantly decreased oxyhemoglobin and deoxy-hemoglobin compared to the dynamic bridging exercise (oxyhemoglobin, t=- 3.109, p=0.007, Cohen's d=0.68 and deoxy-hemoglobin, t=- 2.193, P=0.046, Cohen's d=0.60). The results also demonstrated that after exercise, the dynamic bridging exercise induced a significantly higher oxygenation response (oxygenation, t=- 2.178, P=0.048, Cohen's d=0.43). This study indicates that the dynamic bridging exercise is more effective in improving oxygenation of low back muscles.

Exercise for patients with low back pain

Background: Low back pain (LBP) is a common symptom that imposes a significant socioeconomic burden. Appropriate exercises that enhance the recovery of anatomical structures using biomechanical methods and improve lumbar stability are recommended for patients with LBP. Therefore, clinicians should prescribe appropriate exercises to alleviate LBP, improve function, and prevent recurrence.Current Concepts: Individualized and structured multimodal exercises (strengthening, aerobic, core stability exercises, and stretching) under the supervision of healthcare professionals are recommended for patients with LBP. It is preferable to focus on isometric trunk muscle exercises for strengthening, and strengthening the large muscles (back and gluteal muscles) attached to the thoracolumbar fascia is recommended rather than exercises that involve repeated extension and flexion of the trunk muscles. Individualized aerobic and core stability exercises are recommended, and stretching exercises focusing on extension movements are preferred. It is also important to educate patients regarding the etiology of LBP, harmful postures for LBP, and methods to maintain lumbar lordosis in daily life.Discussion and Conclusion: An appropriate exercise prescription can contribute to better clinical outcomes in patients with LBP. Although exercise is important for recovery and prevention of recurrence, inappropriate exercise can potentially exacerbate LBP; therefore, careful consideration is required.

Comparative efficacy of muscle energy technique and Bowen technique on hamstrings muscle tightness in chronic low back pain patients.

To compare the effects of the Muscle Energy Technique (MET) and the Bowen Technique on hamstring muscle tightness in chronic low back pain (CLBP) patients. A randomized clinical trial (RCT) designed study in which 62 participants were recruited through the purposive sampling technique were divided into two groups by the lottery method. Subjects who had pain for more than six months in the back and hamstring tightness were included. The duration of the study was four months from February to May 2023 conducted at Madinah Teaching Hospital Faisalabad. Subjects in Group-A were given the Bowen technique, whereas subjects in Group-B were given the MET. Numeric pain rating scale (NPRS), Oswestry disability index (ODI), and active knee extension (AKE) tests were used for measurements of outcomes. Intra-group comparison by using Friedman test revealed that both Group-A & B subject's pain were reduced (P<0.000), their tightness in back thigh muscles were significantly reduced (P<0.000) and functional activities of subjects were also improved (P<0.000). Mann Whitney test was used to determine the between group comparison. P-value ≤ 0.05 was considered as significant. Inter Group-Analysis revealed that there was no statistically significant difference between effects of Bowen technique & MET on pain, hamstring tightness and disability as both techniques improved pain, flexibility & disability. This study revealed that both groups treated by MET and Bowen Technique had significantly reduced pain, improved flexibility of back thigh muscle and reduced functional disability.