Neck Muscles Research Articles

Functional and morphological divergence in the forelimb musculoskeletal system of scratch-digging subterranean mammals (Rodentia: Bathyergidae).

Whether the forelimb-digging apparatus of tooth-digging subterranean mammals has similar levels of specialization as compared to scratch-diggers is still unknown. We assessed the scapular morphology and forelimb musculature of all four solitary African mole rats (Bathyergidae): two scratch-diggers, Bathyergus suillus and Bathyergus janetta, and two chisel-tooth diggers, Heliophobius argenteocinereus and Georychus capensis. Remarkable differences were detected: Bathyergus have more robust neck, shoulder, and forearm muscles as compared to the other genera. Some muscles in Bathyergus were also fused and often showing wider attachment areas to bones, which correlate well with its more robust and larger scapula, and its wider and medially oriented olecranon. This suggests that shoulder, elbow, and wrist work in synergy in Bathyergus for generating greater out-forces and that the scapula and proximal ulna play fundamental roles as pivots to maximize and accommodate specialized muscles for better (i) glenohumeral and scapular stabilization, (ii) powerful shoulder flexion, (iii) extension of the elbow and (iv) flexion of the manus and digits. Moreover, although all bathyergids showed a similar set of muscles, Heliophobius lacked the m. tensor fasciae antebrachii (aiding with elbow extension and humeral retraction), and Heliophobius and Georychus lacked the m. articularis humeri (aiding with humeral adduction), indicating deeper morphogenetic differences among digging groups and suggesting a relatively less specialized scratch-digging ability. Nevertheless, Heliophobius and Bathyergus shared some similar adaptations allowing scratch-digging. Our results provide new information about the morphological divergence within this family associated with the specialization to distinct functions and digging behaviors, thus contributing to understand the mosaic of adaptations emerging in phylogenetically and ecologically closer subterranean taxa. This and previous anatomical studies on the Bathyergidae will provide researchers with a substantial basis on the form and function of the musculoskeletal system for future kinematic investigations of digging behavior, as well as to define potential indicators of scratch-digging ability.

Carcass, Egg Characteristics and Leg Bone Dimensions of Pigeons of Different Origin.

In the past, studies have been conducted on the evaluation of meat traits of pigeons, but the knowledge obtained is incomplete and needs to be expanded. The purpose of this study was to obtain information on the weight and proportion of carcass elements, femur and tibia bone dimensions, and egg characteristics of meat of King breed and carrier pigeons. For this study, 16 carcasses of carrier pigeons and 16 carcasses of King pigeons were used, with 8 carcasses of males and 8 carcasses of females of each breed. Additionally, 20 eggs evaluated were from carrier pigeons and 20 eggs from King breed pigeons. The carcasses and eggs were obtained from birds that were 12 months old. The compared pigeon breeds differed (p < 0.05) significantly in terms of the weight of the eviscerated carcass with the neck; the content of neck, wings, pectoral and leg muscles in the carcass; as well as in terms of all specified dimensions of tibia and femur length and width. The origin of the pigeons had an effect (p < 0.05) on egg weight and dimensions, egg index, and the other studied egg traits, with the exception of eggshell weight and eggshell yellowness, yolk weight, yolk height, yolk diameter, and yolk index. So far, there have been no studies comparing carrier pigeons and King breed pigeons in terms of femur and tibia bone dimensions, morphological composition and egg dimensions, and egg content traits, which adds to the knowledge in this area and indicates the need for continuation in the future.

Deglutition dynamics of patients with obstructive sleep apnea.

In the present study, we performed a detailed analysis of deglutitive dynamics during sleep in patients with obstructive sleep apnea (OSA) using a methodology developed by Sato etal. We hypothesized that the frequency of deglutition would decrease with increasing severity of OSA. The aim of this study is to clarify the involvement of deglutitive dynamics during sleep in OSA by investigating the correlations between deglutition and sleep parameters. This study included 30 adult patients with OSA. To analyze deglutition dynamics during sleep, surface electromyography recordings of the suprahyoid and thyrohyoid neck muscles, which are involved in deglutition, were performed simultaneous with conventional polysomnography. The "index of deglutition" was defined as the frequency of deglutition per hour of sleep. We examined correlations between this index and sleep parameters (apnea-hypopnea index [AHI], apnea index, hypopnea index, and lowest blood oxygen saturation). By analyzing the obtained polysomnography and electromyography waveforms, we identified two deglutition patterns with and without respiratory arousal during sleep. We found a significant negative correlation between the index of deglutition in sleep stage 1 and the AHI, with a correlation coefficient of -0.48. (p=0.02). In the current study, we distinguished deglutition during sleep with and without arousal. In addition we discovered a significant negative correlation between the index of deglutition in sleep stage 1 and the AHI. This new finding will provide a platform for future research on OSA in aspiration pneumonia.

Investigating cervical flexion-relaxation ratio in subjects with cervical lateral spinal stenosis compared with asymptomatic controls: A case control study

IntroductionThe cervical flexion-relaxation ratio (FRR) is known as a quantitative measure of the ability of the cervical extensor muscles to relax during the full flexion of the cervical spine. Compared with subjects suffering from non-specific neck pain, the changes occurring in the pattern of the neck muscles' functions in cases with cervical spinal stenosis are not yet well understood. Therefore, this study aimed to compare cervical FRR in subjects with cervical lateral spinal stenosis and asymptomatic controls. MethodsIn total, 25 subjects with cervical lateral spinal stenosis (aged 44.7 ± 10.4) and 25 asymptomatic individuals (aged 44.3 ± 10.8) were included in this study. These participants performed full-neck flexion, and at the same time, the electrical activity of the cervical erector spinae (CES) muscles was recorded bilaterally. Cervical FRR was further calculated by analyzing the electromyographic data recorded for each muscle. ResultsThe mean cervical FRR was significantly lower (P = 0.015) and the FRR asymmetry (ΔFRR) was significantly higher (P = 0.003) in the patients than asymptomatic controls. In addition, the cervical FRR of the involved side was significantly lower in the subjects with cervical pain compared with that in the non-involved one (P = 0.004). There was also a significant difference in the cervical extension (CE) angle between both study groups (P < 0.001), while the cervical flexion (CF) angle was not different (P = 0.25). ConclusionAccording to the study results, FRR and its asymmetry in the subjects with cervical lateral spinal stenosis were significantly different from that in asymptomatic controls and the CE angle declined in these subjects.

Comparative characteristics of cervical sagittal balance parameters and atlantoaxial instability criteria in normal and Down syndrome children

BACKGROUND: Sagittal balance of the spine has received considerable development in recent years. However, most studies focused on the assessment of vertebral–pelvic parameters. The cervical spine has long received insufficient attention from researchers, but this trend has been changing. The study of cervical sagittal balance in children with Down syndrome is beneficial in approaching the preconditions of atlantoaxial instability. AIM: To perform a comparative analysis of cervical sagittal balance parameters and atlantoaxial instability criteria in normal and Down syndrome children. MATERIALS AND METHODS: Radiographs of the cervical spine in the neutral position in lateral projection and postural radiographs of 110 pediatric patients were analyzed retrospectively. The patients were divided into two groups: group 1 (normal), 60 children aged 4–17 years without spinal pathology, and group 2 (Down syndrome), 50 children aged 4–17 years with Down syndrome. The parameters of cervical sagittal balance (Oc-C2, Oc-C7, C1-C2, C2-C7, C2-C7H, C7S, Th1S, TIA, NT) and criteria for atlantoaxial instability (Nakamura angle, ADI, SAC-C1, SAC-C1/SAC-C4) were obtained, and data was statistically analyzed. RESULTS: Significant differences in the parameters C7S, Th1S, and TIA increased in children with Down syndrome. These parameters are involved in cervical lordosis; however, no significant differences in cervical lordosis angles were found. Furthermore, significant differences were noted in the criteria of atlantoaxial instability ADI, SAC-C1, and SAC-C1/SAC-C4 toward their decreasing in children with Down syndrome. CONCLUSION: In patients with Down syndrome, the indices of cervical lordosis are statistically greater than those in normal children. Moreover, the parameters of cervical lordosis in patients with Down syndrome do not differ from those in normal children. Therefore, during flexion, subcompensation of the cervical spine is observed in children with Down syndrome. Given the statistically smaller indicators ADI, SAC-C1, SAC-C1/SAC-C4, low neck muscle tone, and ligamentous hypermobility, these abnormalities can be considered as congenital predisposition factors for atlantoaxial instability in children with Down syndrome.

Evaluation of Apparatus and Protocols to Measure Human Passive Neck Stiffness and Range of Motion

Understanding of human neck stiffness and range of motion (ROM) with minimal neck muscle activation (“passive”) is important for clinical and bioengineering applications. The aim of this study was to develop, implement, and evaluate the reliability of methods for assessing passive-lying stiffness and ROM, in six head-neck rotation directions. Six participants completed two assessment sessions. To perform passive-lying tests, the participant’s head and torso were strapped to a bending (flexion, extension, lateral bending) or a rotation (axial rotation) apparatus, and clinical bed, respectively. The head and neck were manually rotated by the researcher to the participant’s maximum ROM, to assess passive-lying stiffness. Participant-initiated (“active”) head ROM was also assessed in the apparatus, and seated. Various measures of apparatus functionality were assessed. ROM was similar for all assessment configurations in each motion direction except flexion. In each direction, passive stiffness generally increased throughout neck rotation. Within-session reliability for stiffness (ICC > 0.656) and ROM (ICC > 0.872) was acceptable, but between-session reliability was low for some motion directions, probably due to intrinsic participant factors, participant-apparatus interaction, and the relatively low participant number. Moment-angle corridors from both assessment sessions were similar, suggesting that with greater sample size, these methods may be suitable for estimating population-level corridors.

Examining the Backpack Weight Relative to Students' Body Weight Among Urban and Rural Schoolchildren: A Cross-Sectional Study.

Background Schoolbags or backpacks have been an essential part of the education system for a long time. However, a hefty backpack causes the child to arch the back excessively or bend their head and trunk forward to withstand the weight of the schoolbag. If the student carries the backpack on one shoulder, he/she bends to the opposite side to compensate for the extra weight, which may damage the shoulders and spine. Considering these factors, the main aim of this study was to investigate the percentage of backpack weight in proportion to the student's body weight regarding the new guidelines among urban and rural schoolchildren aged 12 to 15 years in Bangalore, Karnataka. Methodology In southern India, over a year, a cross-sectional study was conducted with 500 students who voluntarily participated after providing written consent. They completed a questionnaire, underwent vital and anthropometric measurements, and had their weights measured, including the weights of their backpacks. Sample bags were inspected to determine contributing weight factors and evaluate adherence to timetables. Results The average weight carried by children of all ages was 6.53 kg, averaging 13.53% of their body weight. Among males, the percentage carrying backpacks weighing over 10% of their body weight was 80.9%, while among females, it was 85.7%. Of all the males carrying bags weighing more than 10% of their body weight, 67.7% attended government schools, while 32.3% attended private schools. Among females studying in government schools, 63.6% carried backpacks weighing more than 10% of their body weight, while among those in private schools, 36.4% carried bags exceeding that weight. Conclusions The study concluded that despite regulations being implemented on backpack weight for children, a significant number still carry bags exceeding 10% of their body weight among both urban and rural school children. This could elevate pressure on neck and back muscles, leading to excessive fatigue and potential damage to the skeletal system, ultimately contributing to spinal deformities.

"Efficacy and Safety of OnabotulinumtoxinA for the Treatment of Platysma Prominence: A Randomized Phase 2 Dose-Ranging Study".

With aging, repetitive contraction of the platysma leads to an increase in platysma prominence (PP) characterized by the accentuation of vertical neck bands and blunting of the jawline's contour. This multicenter, double-blind, phase 2 study evaluated onabotulinumtoxinA (onabotA) treatment in adults with Moderate to Severe PP. Participants were randomized to receive 1 treatment of onabotA low dose (LD), onabotA high dose (HD), or placebo, and were followed for 4 months. Efficacy endpoints were the achievement of a ≥ 1-grade improvement on both the left and right sides at Day 14 at maximum contraction as assessed by the investigator (primary) or by participants (secondary) using validated scales. Safety was evaluated throughout. Participants in the modified intent-to-treat population (N = 164) had a mean age of 50 years; 95.1% were female and 93.9% were White. The primary endpoint was met for both onabotA groups, with investigator-assessed ≥ 1-grade improvement in 77.8% (LD) and 88.2% (HD) vs 12.0% (placebo) of participants on Day 14 (P < 0.0001 vs placebo). Based on participant self-assessment, 75.9% (LD) and 88.2% (HD) vs 18.0% (placebo) achieved ≥ 1-grade improvement on Day 14 (P < 0.0001 vs placebo). Most treatment-related adverse events (AEs) were procedure-related, transient, and mild in severity. The most frequent onabotA-related AE was neck muscle weakness, reported in the HD group. OnabotA was effective in improving the appearance of PP based on both investigators' and participants' ratings. Treatment was well tolerated.

A research on an improved fuzzy approximate entropy algorithm for EMG-based shoulder and neck muscle fatigue detection

A robust muscle fatigue algorithm plays a pivotal role in depicting the degree of muscle fatigue in both time-series EMG signal graphs and spectral graphs, aligning with human perception. While the fuzzy approximate entropy (fApEn) algorithm has been enhanced from the foundation of approximate entropy (ApEn) through the incorporation of fuzzy affiliation, concerns persist regarding the threshold value and the algorithm’s application range. This study extracts EMG signals across varied time durations and head-down angles, employing enhanced signal preprocessing techniques and optimizing the fApEn algorithm. Furthermore, real-time fatigue perceptions of subjects were recorded using the rating of perceived exertion. Experimental outcomes reveal that the EMG signal, post-wavelet analysis preprocessing, demonstrates promising noise reduction capabilities. Notably, the fApEn algorithm exhibits considerable enhancements through the identification of an optimal threshold using the gradient descent algorithm and a machine learning strategy.

A six degrees-of-freedom cable-driven robotic platform for head-neck movement.

This paper introduces a novel cable-driven robotic platform that enables six degrees-of-freedom (DoF) natural head-neck movements. Poor postural control of the head-neck can be a debilitating symptom of neurological disorders such as amyotrophic lateral sclerosis and cerebral palsy. Current treatments using static neck collars are inadequate, and there is a need to develop new devices to empower movements and facilitate physical rehabilitation of the head-neck. State-of-the-art neck exoskeletons using lower DoF mechanisms with rigid linkages are limited by their hard motion constraints imposed on head-neck movements. By contrast, the cable-driven robot presented in this paper does not constrain motion and enables wide-range, 6-DoF control of the head-neck. We present the mechatronic design, validation, and control implementations of this robot, as well as a human experiment to demonstrate a potential use case of this versatile robot for rehabilitation. Participants were engaged in a target reaching task while the robot applied both assistive and resistive moments on the head during the task. Our results show that neck muscle activation increased by 19% when moving the head against resistance and decreased by 28-43% when assisted by the robot. Overall, these results provide a scientific justification for further research in enabling movement and identifying personalized rehabilitation for motor training. Beyond rehabilitation, other applications such as applying force perturbations on the head to study sensory integration and applying traction to achieve pain relief may benefit from the innovation of this robotic platform which is capable of applying controlled 6-DoF forces/moments on the head.

Impact of the COVID-19 pandemic on clinical and psychological aspects of temporomandibular disorders

BackgroundThe Coronavirus 2019 disease (COVID-19) caused drastic changes in people’s lifestyle that affected TMD characteristics through its physical and psychological influences. The aim of this study was to define the clinical and psychological characteristics of a large group of well-defined TMD patients and seek their differences between before and during the COVID-19 pandemic to establish points of care to be emphasized in the post-pandemic era.MethodsTMD patients diagnosed by the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) aged ≥ 18 were analyzed. Samples between September, 2017 to July, 2019 (n = 455) and March, 2021 to June, 2022 (n = 338) were collected to represent before and during COVID-19, respectively. The Graded Chronic Pain Scale (GCPS) and Symptom Checklist-90-Revision (SCL-90-R) were used to evaluate disability levels and psychological status. Clinical indices were compared between COVID periods and factors related to higher pain levels were investigated according to pandemic period.ResultsMore patients reported pain on palpation of the masticatory muscles during the pandemic (p = 0.021) while the number decreased for neck muscles (p = 0.001) and TMJ (p < 0.001) areas. Patients reporting nocturnal bruxism (23.3–29.6%) and clenching (45.1–54.7%) significantly increased during the pandemic. TMD patients with pain without disability were more common during the pandemic regardless of pain intensity (p < 0.001). The number of patients expressing interference in daily activities decreased drastically during COVID-19 regardless of disability level (p < 0.001). Factors associated with higher than moderate pain intensity (CPI ≥ 50) were insomnia (odds ratio [OR] = 1.603, p = 0.047) and somatization (OR = 1.082, p < 0.001) before the pandemic. During the pandemic, age (OR = 1.024, p = 0.007), somatization (OR = 1.070, p = 0.006), and paranoid ideation (OR = 1.117, p = 0.003) were significantly associated with higher pain intensity.ConclusionsThe results of our study underline the importance of evaluating psychological profiles of TMD patients, especially somatization, paranoid ideation and psychoticism, in exceptional situations that may cause a change in individual mental status. This will lead to a better understanding of the individual TMD patient and help in planning personalized treatment strategies that will assist the patient in adjusting to changes occurring in special environments such as the COVID-19 pandemic.

Remarkable clinical improvement with oral nucleoside treatment in a patient with adult-onset TK2 deficiency: A case report

ObjectivesThymidine kinase 2 deficiency (TK2d) is a rare autosomal recessive mitochondrial disorder. It manifests as a continuous clinical spectrum, from fatal infantile mitochondrial DNA depletion syndromes to adult-onset mitochondrial myopathies characterized by ophthalmoplegia-plus phenotypes with early respiratory involvement. Treatment with pyrimidine nucleosides has recently shown striking effects on survival and motor outcomes in the more severe infantile-onset clinical forms. We present the response to treatment in a patient with adult-onset TK2d. MethodsAn adult with ptosis, ophthalmoplegia, facial, neck, and proximal muscle weakness, non-invasive nocturnal mechanical ventilation, and dysphagia due to biallelic pathogenic variants in TK2 received treatment with 260 mg/kg/day of deoxycytidine (dC) and deoxythymidine (dT) under a Compassionate Use Program. Prospective motor and respiratory assessments are presented. ResultsAfter 27 months of follow-up, the North Star Ambulatory Assessment improved by 11 points, he walked 195 m more in the 6 Minute-Walking-Test, ran 10 s faster in the 100-meter time velocity test, and the Forced Vital Capacity stabilized. Growth Differentiation Factor-15 (GDF15) levels, a biomarker of respiratory chain dysfunction, normalized. The only reported side effect was dose-dependent diarrhea. DiscussionTreatment with dC and dT can significantly improve motor performance and stabilize respiratory function safely in patients with adult-onset TK2d.

The role of muscle forces in neck comfort for static seating: a pilot study

Aircraft seats play a key role in the competition between aircraft companies seeking to differentiate themselves in terms of passengers’ inflight experience. The seat design process relies on computational and experimental methods based on subjective measures, such as comfort rating questionnaires, and objective comfort indicators of seat-occupant interaction, such as contact pressure distribution and muscle activation. Previous studies around muscle activity for seating comfort assessment have primarily focused on more active scenarios or active systems. As such, there are limited studies about the role of muscle force in normal and relaxed sitting conditions, common in aircraft settings. This paper explores the relationship between activities of the neck muscles, sternocleidomastoid, and upper trapezius, measured from human participants seated sedentarily on conventional business aircraft seats and their perceived comfort with different backrest inclinations. The results show, for normal seating without neck pillow, no significant association is found between the backrest inclination and the neck’s comfort or muscle activation. For general seating across different backrest inclinations, a positive medium correlation between muscle activation and comfort is found in upper trapezius (R = 0.5332, p = 0.0187). This work serves as a pilot study of this new approach of comfort evaluation using muscle feedback in seat designing processes and highlights the posterior’s effect to seating experience in the neck region.

Quantitative comparison of three thyroidectomy approaches on neck muscles, voice, and swallowing functions

ObjectiveThis study compares endoscopic thyroidectomy by gasless unilateral axillary approach (ETGUA) and sternocleidomastoid leading-edge approach (SLEA) with conventional open thyroidectomy (COT) in hemithyroidectomy. The main focus is on the protection of neck muscles (sternocleidomastoid, omohyoid, sternothyroid) and the postoperative function of voice and swallowing yielded through these common approaches. MethodsA total of 302 patients who underwent hemithyroidectomy were enrolled and divided into three groups: ETGUA (n = 101), SLEA (n = 100), and COT (n = 101). Ultrasound was used to measure the thickness of bilateral neck muscles, including the sternocleidomastoid, omohyoid, and sternothyroid. The changes in thickness on the surgical side compared to the non-surgical side. Analyzed factors included muscle thickness changes, Swallowing Impairment Score (SIS), Voice Handicap Index (VHI), Scar Cosmesis Assessment and Rating (SCAR), Neck Incision Index (NII), surgery duration, drainage volume, hospitalization, and number of lymph nodes. ResultsThe clinical characteristics among the three groups were consistent except for differences in sex, age, and BMI. Metrics such as sternocleidomastoid muscle, NII, hypocalcemia, postoperative PTH, transient hoarseness, and number of lymph nodes showed no significant differences among the three groups. However, significant differences were found in the duration of surgery, drainage volume, hospitalization period omohyoid muscle, Sternohyoid muscle, VHI, SIS, and SCAR (all p < 0.001). ConclusionIn comparison to COT, ETGUA and SLEA demonstrate superiority in protecting neck muscles and preserving voice and swallowing function without compromising surgical safety or radicality.

Evaluation of oVEMP and cVEMP in Superior Semicircular Canal Dehiscence Cases

Superior semisircular canal dehiscence (SSCD) is a disease of the audiovestibular system, which occurs as a result of the lack of bone layer covering the superior semisircular canal. The disease forms a third window in the inner ear due to the lack of bone layer. The third window that occurs forms a pseudo conductive type of hearing loss, which has decreased bone thresholds in the audiometry test. Vestibular evoked myogenic potentials are an electrophysiological measurement method in which the responses of the neck or eye muscles to an acoustic stimulus are recorded by means of electrodes. The purpose of use is to evaluate the functions of the urticle and saccule, which are the vestibular end organs. Therefore its primary purpose is to diagnose semicircular canal dehiscence. This review is based on research from the last decade; diagnostic results of ocular vestibular evoked myogenic potentials (oVEMP) and cervical vestibular evoked myogenic potentials (cVEMP) tests were evaluated in cases of superior semicircular canal dehiscence (SSCD). Studies indicate abnormal decreases in cVEMP test thresholds on the affected side in SSCD cases. Additionally, a significant increase in oVEMP amplitude on the affected side has been reported. Results; It shows that evaluating these two tests together will contribute to the diagnosis of semicircular canal dehiscence cases.

New insights into morphological adaptation in common mole-rats (Cryptomys hottentotus hottentotus) along an aridity gradient.

Morphological adaptation is the change in the form of an organism that benefits the individual in its current habitat. Mole-rats (family Bathyergidae), despite being subterranean, are impacted by both local and broad-scale environmental conditions that occur above ground. Common mole-rats (Cryptomys hottentotus hottentotus) present an ideal mammalian model system for the study of morphological variation in response to ecology, as this species is found along an aridity gradient and thus can be sampled from geographically non-overlapping populations of the same species along an environmental longitudinal cline. Using the mass of five internal organs, ten skeletal measurements and 3D morphometric analyses of skulls, we assessed the morphology of wild non-breeding individuals from five common mole-rat populations in South Africa. We found that the body mass and mean relative mass of the spleen and kidneys in arid populations was larger, and individuals from arid regions possessed shorter legs and larger inter-shoulder widths compared to individuals from mesic regions. Additionally, arid populations demonstrated greater skull depth, and shape change of features such as angular processes of the lower jaw than mesic individuals, indicating that these distinct geographic populations show differences corresponding to the aridity gradient, potentially in response to environmental factors such as the variation in food sources found between different habitats, in addition to different soil compositions found in the different regions. Arid populations potentially require a stronger jaw and neck musculature associated with mastication to chew xeric-adapted plants and to dig through hard soil types, whereas mesic populations excavate through soft, looser soil and may make use of their front limbs to aid the movement of soils when digging. Aridity influences the morphology of this species and could indicate the impact of environmental changes on speciation and mammalian skull morphology.

Effects of scapular treatment on chronic neck pain: a systematic review and meta-analysis of randomized controlled trials

BackgroundChronic neck pain (CNP) is a common public health problem that affects daily living activities and quality of life. There is biomechanical interdependence between the neck and scapula. Studies have shown that shoulder blade function might be related to chronic neck pain. We therefore evaluated the effects of scapular targeted therapy on neck pain and function in patients with CNP.MethodsDatabases, including MEDLINE (via PubMed), EMBASE (via Ovid), Ovid, Web of Science, and Scopus, were systematically searched for randomized controlled trials published in English investigating treatment of the scapula for CNP before July 16, 2023.ResultsA total of 313 participants were included from 8 RCTs. Compared with those in the control group, the intervention in the scapular treatment group exhibited greater improvement in pain intensity (standardized mean difference (SMD) = 2.55; 95% CI = 0.97 to 4.13; P = 0.002), with moderate evidence. Subgroup analysis for pain intensity revealed a significant difference between the sexes, with only the female population (SMD = 6.23, 95% CI = 4.80 to 7.65) showing better outcomes than those with both sexes (SMD = 1.07, 95% CI = 0.57 to 1.56) (p < 0.00001). However, moderate evidence demonstrated no improvement in neck disability after scapular treatment (SMD of 0.24[-0.14, 0.62] of Neck Disability Index or Northwick Park Neck Pain Questionnaire). No effect of scapular treatment was shown on the pressure pain threshold (PPT). The cervical range of motion (CROM) and electromyographic activity of neck muscles could not be conclusively evaluated due to limited support in the articles, and further study was needed. However, the patient’s head forward posture appeared to be corrected after scapular treatment.ConclusionScapular therapy was beneficial for relieving pain intensity in patients with CNP, especially in women. Head forward posture might also be corrected with scapular therapy. However, scapular therapy may have no effect on the PPT or neck disability. However, whether scapular therapy could improve CROM and cervical muscle activation in patients with CNPs had not been determined and needed further study.

Swallowing-related muscle inflammation and fibrosis induced by a single dose of radiation exposure in mice

BackgroundAlthough radiotherapy is commonly used to treat head and neck cancer, it may lead to radiation-associated dysphagia (RAD). There are various causes of RAD, however, the mechanism has not yet been fully identified. Currently, the only effective treatment for RAD is rehabilitation. Additionally, there are few available animal models of RAD, necessitating the development of new models to establish and evaluate RAD treatments. We hypothesize that radiation-induced neck muscle fibrosis could be one of the causes of RAD due to impairment of laryngeal elevation. Therefore, in this study, we focused on the changes in inflammation and fibrosis of the strap muscles (Sternohyoid, Sternothyroid, and Thyrohyoid muscles) after a single-dose irradiation. This research aims to provide a reference animal model for future studies on RAD.ResultsCompared to control mice, those treated with 72-Gy, but not 24-Gy, irradiation had significantly increased tumor necrosis factor-α (TNF-α) (p < 0.01) and α-smooth muscle actin (αSMA) (p < 0.05) expression at 10 days and significantly increased expression levels of motif chemokine ligand-2 (CCL2), α-SMA, tumor growth factor-β1 (TGF-β1), type1 collagen, and interleukin-1β (IL-1β) (p < 0.05) in the muscles at 1 month by real-time PCR analysis. The results of immunohistochemistry showed that the deposition of type 1 collagen gradually increased in extracellular space after radiation exposure, and the positive area was significantly increased at 3 months compared to non-irradiated control.ConclusionsA single dose of 72-Gy irradiation induced significant inflammation and fibrosis in the strap muscles of mice at 1 month, with immunohistochemical changes becoming evident at 3 months. This cervical irradiation-induced fibrosis model holds potential for establishing an animal model for RAD in future studies.Level of evidenceN/A.

Forward Head Posture and Its Effect on Muscle Activation

Forward head posture (FHP), which is defined as a forward displacement of the head on the cervical spine, is a common postural disorder. It is suggested that this malalignment alters the loads on the spine, affects the length-tension relationship in muscles, and changes muscle activation. Therefore, the aim of this review is to investigate the results of studies on the examination of the changes exerted by FHP on muscle activation. Although there are many methods used to assess FHP, there is no standard clinical method for accurate measurement of this angle. Photographic measurement is the most widely used, valid, and reliable assessment method. Craniovertebral angle (CVA) is the most widely used value to assess FHP in photographic measurements. A CVA of less than 48-50° is defined as FHP, although there are differences regarding the norm value of the CVA. There are many studies on the assessment of differences in the activation of the neck and shoulder muscles by making FHP and non-FHP classifications according to the CVA to show the changes in muscle activation in individuals with FHP. Although many studies have shown increased sternocleidomastoideus and upper trapezius activation, there are also others indicating no difference. Similar conflicting results exist for the lower trapezius and serratus anterior muscles. Although there are conflicting results regarding muscle activation in studies, it seems likely that muscle activation is altered in individuals with FHP. It may be recommended that physiotherapists conduct interventions by considering these differences in muscle activation in individuals with FHP.

Sleep and Thermoregulation in Birds: Cold Exposure Reduces Brain Temperature but Has Little Influence on Sleep Time and Sleep Architecture in Jackdaws (Coloeus monedula).

Birds have an electrophysiological sleep state that resembles mammalian rapid-eye-movement (REM) sleep. However, whether its regulation and function are similar is unclear. In the current experiment, we studied REM sleep regulation in jackdaws (Coloeus monedula) by exposing the birds to low ambient temperature, a procedure that selectively suppresses REM sleep in mammals. Eight jackdaws were equipped with electrodes to record brain activity and neck muscle activity and a thermistor to record cortical brain temperature. Recordings covered a three-day period starting with a 24 h baseline day at an ambient temperature of 21 °C, followed by a 12 h cold night at 4 °C, after which the ambient temperature was restored to 21 °C for the remaining recovery period. Cold exposure at night caused a significant drop in brain temperature of 1.4 °C compared to the baseline night. However, throughout the cold night, jackdaws expressed NREM sleep and REM sleep levels that were not significantly different from the baseline. Also, EEG spectral power during NREM sleep was unaffected by cold exposure. Thus, while cold exposure had a clear effect on brain temperature in jackdaws, it did not have the same REM sleep suppressing effect reported for mammals. These findings suggest that the REM-sleep-like state in birds, unlike REM sleep in mammals, is protected against the influence of low temperature.