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Alabama (AL) is a hotspot in the Gulf of Mexico (GoM) for human interaction-related cetacean strandings, including harassment, vessel strikes, and fisheries interactions. We examined four bottlenose dolphins ( Tursiops truncatus ) stranded dead along the AL coast during 2012-2017 with severed peduncles suspected to be related to human interaction (HI). Evidence from each case, including photographs, gross necropsy results, and histopathologic findings when available, was reviewed to determine the mode of severance and whether it contributed to death. In each case, the severance site had smooth, clean edges on at least one side, indicating the use of a sharp instrument to remove the caudal peduncle and flukes. Three cases also had evidence of fisheries interactions, including linear impressions around the rostrum, fins and/or flukes, indicating that these animals may have been entangled in fisheries gear prior to death. Histopathology in one of these cases revealed that the severance occurred perimortem; speculatively, the caudal peduncle and flukes may have been cut off to facilitate removing the dolphin from its entanglement. Although cases of amputation and mutilation are not uncommon globally among stranding reports, few cases have been described and analyzed in the literature. This paper is the first to document and compare multiple cases of severed peduncles with evidence of HI, including fisheries, in the GoM. This case series enhances our understanding of the types of HI occurring in bottlenose dolphins and highlights the need for continued public education, policy, and management to address cases like these.

Background: Monitoring muscle damage in athletes assists not only coaches to adjust the training workload but also medical staff to prevent injury. Measuring blood myoglobin concentration can help evaluate muscle damage. The novel portable device utilized in this study allows for easy on-site measurement of myoglobin, providing real-time data on the player's muscle damage. This study investigated the relationship between external load (global positioning system parameters) and internal loads (myoglobin concentration and creatine kinase activity) in 15 male professional football players before and after a match., Methods: Whole blood samples from participants' fingertips were collected before the match (baseline) and at 2, 16, and 40 h after the match. Myoglobin concentrations were measured using the IA-100 compact immunoassay system. Creatine kinase concentrations were measured in a clinical laboratory, and match loads were monitored using a global positioning system device., Results: The mean myoglobin concentration was significantly higher at 2 h than at the other time points (P<0.05), and decreased to baseline levels within 16 h post-match. The mean creatine kinase concentration increased after the match but did not reach a significant level. Muscle damage monitored by myoglobin after football match-play was strongly associated with acceleration/deceleration metrics rather than the sprint/high-speed running distance., Conclusions: Our findings indicate that myoglobin is a more sensitive marker of muscle damage than creatine kinase after football match-play. Monitoring myoglobin in athletes can aid in determining their recovery status from the previous training load and help practitioners manage the training load.

This study was to investigate the effects of 13 weeks of long-distance cycling on biomarkers of joint cartilage, muscle damage and inflammation. All subjects in this study were seven participants of the “One Korea New-Eurasia Peace Cycle Expedition”, in which they rode cycles from Berlin, Germany to Seoul, Korea for thirteen weeks. The total course of the expedition was divided into three sub-courses: course 1 (from Berlin to Moscow), course 2 (from Moscow to Ulaanbaatar) and course 3 (from Ulaanbaatar to Seoul). All the selected participants rode 87.4 km/day (course 1), 70.4 km/day (course 2) and 57.6 km/day (course 3) on average, respectively. We collected their blood samples before the expedition in Seoul (S1), after course 1 in Moscow (M), after course 2 in Ulaanbaatar (U) and after the expedition in Seoul (S2), to analyze biomarkers of joint cartilage damage (Cartilage Oligomeric Matrix Protein; COMP), muscle damage (Creatine Phosphokinase; CPK, Lactate Dehydrogenase; LDH, Myoglobin), inflammation (Interleukin-6; IL-6, Interleukin-1β; IL-1β, Tumor Necrosis Factor-α; TNF-α, C-Reactive Protein; CRP) and stress hormone (Cortisol). According to this result, COMP (S1; 188.37 ± 46.68 ng/mL) showed a significant increase after the expedition course 1 (M; 246.69 ± 51.69 ng/mL, p = 0.012) and course 2 (U; 237.09 ± 62.57 ng/mL, p = 0.047), and recovered to the stable state after expedition course 3 (S2; 218.46 ± 34.78. p = 0.047). Biomarkers of muscle damage (CPK, LDH and Myoglobin) and inflammation (IL-6, IL-1β, TNF-α and CRP) were not significantly changed in all courses, but CRP (S1; 1.07 ± 0.76 ng/mL) showed a tendency to decrease after the expedition course 1 (M; 0.3 ± 0.1 mg/mL, p = 0.044). Lastly, the Cortisol level significantly increased in all courses (per p < 0.05), but the Cortisol level after expedition course 3 (S2; 21.00 ± 3.65 mg/mL) was lower than that of after the expedition course 1 (M; 24.23 ± 2.47 mg/mL, p = 0.028). In summary, it seems that repetitive and continuous 50−90 km/day of cycling can increase joint cartilage damage risk and stress hormone temporarily. However, this result suggests that the appropriate intensity of cycling for thirteen weeks does not increase physical damage, and rather enhances the human body to adapt to exercise training.

Background: The study aimed at exploring whether muscle membrane disruption, as a surrogate for muscle damage, and inflammation recovery following a mountain ultramarathon (MUM) was related with race performance and postrace physical activity., Methods: Blood samples were obtained from thirty-four athletes (29 men and 5 women) before a 118-km MUM, immediately after and three- and seven-days postrace. Creatine kinase (CK), lactate dehydrogenase (LDH) and C-reactive protein (CRP) were compared between faster (FR) and slower (SR) runners. Physical activity performed during the week following the MUM was objectively analyzed using accelerometers and compared between FR and SR., Results: CK was significantly higher in FR at 3 days postrace (P<0.012, d=1.17) and LDH was significantly higher in FR at 3- and 7-days postrace (P=0.005, d=1.01; P<0.015, d=1.05 respectively), as compared to SR. No significant differences were identified in postrace physical activity levels between FR and SR. Significant relationships were found between race time and CK and LDH concentrations at 3 days postrace (rs=-0.41, P=0.017; rs=-0.52, P=0.002 respectively) and 7 days postrace (rs=-0.36, P=0.039; rs=-0.46. P=0.007 respectively). However, postrace physical activity was not associated with muscle damage and inflammation recovery, except for light intensity and CRP at 3 days postrace (rs=-0.40, P=0.025)., Conclusions: Race time appeared to have a higher influence on muscle damage recovery than the intensity of physical activities performed in the week after running a MUM. Inflammatory activity takes longer to normalize than muscle damage following a MUM, it is not related with race time and lightly related with postrace physical activity.

Objectives: The aims of this study were to develop a clinical-feature based scoring system for muscle injury screening and to assess its diagnostic accuracy when large number of injuries are suspected., Methods: A prospective diagnostic accuracy study was performed according to the Standards for Reporting of Diagnostic Accuracy (STARD) criteria. The diagnostic accuracy of the Strength and Pain Assessment (SPA) score (index test) was assessed in relation to muscle ultrasonography (reference standard). A large (n = 175) number of male soccer players met the inclusion/exclusion criteria: clinical assessment (i.e., evaluation of pain onset modality, location, distribution, impact on performance, and manual muscle strength testing) and ultrasonography were performed in all players after 48 hours from the sudden or progressive onset of muscle pain during or after a soccer competition., Results: 91 of 175 cases (52%) were classified as functional muscle disorders, while signs of muscle tear were observed in the remaining 84 of 175 (48%) cases that were classified as structural muscle injuries. The median (1st - 3rd quartile) value of the SPA score was significantly (P < 0.001) lower in the functional disorder group [9 (9-10)] compared to the structural injury group [12 (12-13)]. The area under the Receiver Operating Characteristic curve for different cutoff points of the SPA score was 0.977 (95% confidence intervals: 0.957-0.998) and the optimal cutoff value of the SPA score providing the greatest sensitivity and specificity (respectively, 99% and 89%) was 11., Conclusion: This study found that the SPA score has high diagnostic accuracy for structural muscle injuries and could be used as a valid screening tool in soccer players presenting with sudden or progressive onset of muscle pain during or after a competition.

Background: Musculoskeletal (MSK) conditions, MSK pain and MSK injury/trauma are the largest contributors to the global burden of disability, yet global guidance to arrest the rising disability burden is lacking. We aimed to explore contemporary context, challenges and opportunities at a global level and relevant to health systems strengthening for MSK health, as identified by international key informants (KIs) to inform a global MSK health strategic response., Methods: An in-depth qualitative study was undertaken with international KIs, purposively sampled across high-income and low and middle-income countries (LMICs). KIs identified as representatives of peak global and international organisations (clinical/professional, advocacy, national government and the World Health Organization), thought leaders, and people with lived experience in advocacy roles. Verbatim transcripts of individual semi-structured interviews were analysed inductively using a grounded theory method. Data were organised into categories describing 1) contemporary context; 2) goals; 3) guiding principles; 4) accelerators for action; and 5) strategic priority areas (pillars), to build a data-driven logic model. Here, we report on categories 1-4 of the logic model., Results: Thirty-one KIs from 20 countries (40% LMICs) affiliated with 25 organisations participated. Six themes described contemporary context (category 1): 1) MSK health is afforded relatively lower priority status compared with other health conditions and is poorly legitimised; 2) improving MSK health is more than just healthcare; 3) global guidance for country-level system strengthening is needed; 4) impact of COVID-19 on MSK health; 5) multiple inequities associated with MSK health; and 6) complexity in health service delivery for MSK health. Five guiding principles (category 3) focussed on adaptability; inclusiveness through co-design; prevention and reducing disability; a lifecourse approach; and equity and value-based care. Goals (category 2) and seven accelerators for action (category 4) were also derived., Conclusion: KIs strongly supported the creation of an adaptable global strategy to catalyse and steward country-level health systems strengthening responses for MSK health. The data-driven logic model provides a blueprint for global agencies and countries to initiate appropriate whole-of-health system reforms to improve population-level prevention and management of MSK health. Contextual considerations about MSK health and accelerators for action should be considered in reform activities., (© 2021. The Author(s).)

Core muscle injury is a common but difficult problem to treat. Although it can affect all individuals, it is most commonly seen in male athletes in cutting, twisting, pivoting, and explosive sports. Owing to the high association of femoroacetabular impingement, we believe these individuals are best treated with a multidisciplinary approach involving both orthopedic and general surgeons. Conservative treatment should be the first step in management. When conservative means are unsuccessful, operative intervention to correct all the pathologic issues around the pubis can have extremely high success rates., Competing Interests: Disclosure The authors have nothing to disclose., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Key hole surgery was recruited for MVD surgery since the maneuver is through the small space between the cerebellum and temporal/occipital bone. However, even small wounds can cause severe postoperative pain if there is significant tissue damage. Attention has been given to the size of the craniotomy rather than to the skin incision or soft tissues such as muscles., Method: Suboccipital muscle dissection focusing on splitting the splenius capitis muscle was presented. The dura was reapproximated without additional dissection to harvest a fascia graft., Conclusion: Muscle injury should be minimized to alleviate postoperative pain.

The myotendinous junction (MTJ) is at high risk of muscle injury, and collagen XXII is strictly expressed at tissue junctions, specifically at the MTJ. We investigated the hypothesis that single-nucleotide polymorphisms (SNPs) related to collagen type XXII α-1 chain gene ( COL22A1 ) mRNA expression are associated with susceptibility to muscle injury in athletes. History of muscle injury was assessed in 3,320 Japanese athletes using a questionnaire, and two expression quantitative trait loci (eQTL) SNPs for COL22A1 (rs11784270 A/C and rs6577958 T/C) were analyzed using the TaqMan SNP Genotyping Assay. rs11784270 [odds ratio (OR) = 1.80, 95% confidence interval (CI) = 1.27-2.62, P = 0.0006] and rs6577958 (OR = 1.45, 95% CI = 1.10-1.94, P = 0.0083) were significantly associated with muscle injury under A and T allele additive genetic models, respectively. These results suggest that the expression level of COL22A1 at the MTJ influences muscle injury risk in athletes.

Purpose: Tc-99m methylene diphosphonate ([ 99m Tc]MDP) is an in vivo bone imaging agent that also accumulates in injured skeletal muscle cells. The objective of this study was to investigate if [ 99m Tc]MDP could be used to detect muscle injury in the mdx mouse model of Duchenne muscular dystrophy (DMD)., Procedures: Static whole-body single-photon emission computed tomography/computed tomography (CT) scans were acquired at 2 h post-injection of [ 99m Tc]MDP in two cohorts of animals at different sites: one cohort of mice at 6, 15, and 19 weeks of age, and a separate cohort at 16 weeks. The second cohort was also imaged with high-resolution CT at 8 weeks., Results: mdx mice had higher [ 99m Tc]MDP uptake and significantly higher [ 99m Tc]MDP concentrations in muscle than controls., Conclusions: Higher uptake of [ 99m Tc]MDP in muscle of mdx mice agrees with histological reports of muscle calcification in mdx mice, and suggests the potential translational use of [ 99m Tc]MDP imaging for tracking DMD progression and therapeutic response.

Integration of extracellular matrix (ECM)-derived cues into transcriptional programs is essential primarily in rapidly morphing environments, such as regenerating tissues. Here, we demonstrate that lysyl oxidase (Lox), known for its ECM-modifying activities, primarily collagen crosslinking, also directly regulates transcription factor (TF) localization. Using genetic and pharmacological strategies, we highlight an intracellular role for Lox in myogenic progenitors essential for muscle regeneration. We show that Lox interacts with, and directly oxidizes, vestigial-like 3 (Vgll3), a transcriptional co-activator acting with Mef2 and transcriptional enhancer factor (TEF) TFs. This enzymatic activity is required for Vgll3 cytoplasmic-to-nuclear translocation in regulation of myogenic differentiation. Our work highlights an additional mechanism for TF subcellular localization facilitating integration of ECM organization with transcriptional output during myogenic differentiation. Modulating this integration mechanism could affect the balance between ECM organization and cell differentiation and serve as a basis for novel therapeutic strategies targeting fibrotic pathologies., Competing Interests: Declaration of Interests The authors declare no competing interests., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Dystrophic muscle is characterized by chronic injury and a steady recruitment of inflammatory Ly6Chi monocytes. Recent studies have identified the spleen as the dominant reservoir of these cells during chronic inflammation. Here, we investigated the contribution of splenic Ly6Chi monocytes to dystrophic muscle pathology. Using the mdx mouse model of muscular dystrophy, we show that Ly6Chi monocytes accumulate in great numbers in the spleen over the course of the disease. The chemokine receptor CCR2 was upregulated on Ly6Chi monocytes in mdx spleen before disease onset, thereby enabling their recruitment to dystrophic muscle. Splenectomy performed before disease onset significantly reduced the number of Ly6Chi monocytes infiltrating dystrophic limb muscle. Moreover, in the absence of splenic Ly6Chi monocytes there was a significant reduction in dystrophic muscle inflammation and necrosis, along with improved regeneration during early disease. However, during late disease, a lack of splenic Ly6Chi monocytes adversely affected muscle fiber repair, due to a delay in the phenotypic shift of proinflammatory F4/80+Ly6ChiCD206lo to antiinflammatory F4/80+Ly6CloCD206+ macrophages. Overall, we show that the spleen is an indispensable source of Ly6Chi monocytes in muscular dystrophy and that splenic monocytes are critical players in both muscle fiber injury and repair.

Purpose: Muscle wasting is common amongst patients with persistent critical illness and associated with increased urea production, but reduced creatinine production. We hypothesised that elevated urea:creatinine ratio would provide a biochemical signature of muscle catabolism and characterise prolonged intensive care (ICU) admissions after major trauma., Methods: Using pre-specified hypotheses, we analysed two existing data sets of adults surviving ≥ 10 days following admission to ICU after major trauma. We analysed trauma-ICU admissions to the major trauma centre serving the North East London and Essex Trauma Network, with a verification cohort of trauma-ICU cases from the MIMIC-III database. We compared serum urea, creatinine, and urea:creatinine ratio (ratio of concentrations in mmol/L) between patients with persistent critical illness (defined as ICU stay of ≥ 10 days) and those discharged from ICU before day 10. In a sub-group undergoing sequential abdominal computerised tomography (CT), we measured change in cross-sectional muscle area (psoas muscle at L4 vertebral level and total muscle at L3 level) and assessed for relationships with urea:creatinine ratio and ICU stay. Results are provided as median [interquartile range]., Results: We included 1173 patients between February 1st, 2012 and May 1st, 2016. In patients with ICU stay ≥ 10 days, day 10 urea:creatinine ratio had increased by 133% [72-215], from 62 [46-78] to 141 [114-178], p < 0.001; this rise was larger (p < 0.001) than in patients discharged from ICU before day 10, 59% [11-122%], 61 [45-75] to 97 [67-128], p < 0.001. A similar separation in trajectory of urea:creatinine ratio was observed in 2876 trauma-ICU admissions from MIMIC-III. In 107 patients undergoing serial CTs, decrease in L4 psoas and L3 muscle cross-sectional areas between CTs significantly correlated with time elapsed (R 2  = 0.64 and R 2  = 0.59, respectively). Rate of muscle decrease was significantly greater (p < 0.001 for interaction terms) in 53/107 patients with the second CT during evolving, current or recent persistent critical illness. In this group, at the second CT urea:creatinine ratio negatively correlated with L4 psoas and L3 muscle cross-sectional areas (R 2 0.39, p < 0.001 and 0.44, p < 0.001)., Conclusion: Elevated urea:creatinine ratio accompanies skeletal muscle wasting representing a biochemical signature of persistent critical illness after major trauma. If prospectively confirmed, urea:creatinine ratio is a potential surrogate of catabolism to examine in epidemiological and interventional studies.

Repair of volumetric muscle loss (VML) injuries is a complicated endeavour which necessitates the collaborative use of different regenerative approaches and technologies. Herein is proposed the development of fibrin-based microbeads (FMs) alone or as a bone marrow mesenchymal stem cell (MSC) encapsulation matrix for modular muscle engineering. FMs were generated through the ionotropic gelation of alginate and fibrinogen obtained from the platelet-rich plasma of whole blood, and then removing the alginate by citrate treatment. FMs were first characterized by FT-IR, SEM and water uptake tests. Then, the stability of FMs and the mitochondrial dehydrogenase activity of the MSCs encapsulated in FMs were evaluated under in vitro culture conditions. Eventually, the regenerative capacity of the cell-devoid and MSCs-encapsulated FMs was evaluated in a rat VML injury model involving 8 × 4×4 mm 3 -size bilateral defects in the biceps femoris muscles. The histochemical, immunohistochemical and semi-quantitative histomorphological scoring results retrieved at 30, 60 and 180 days demonstrated that the cell-devoid FMs supported muscle regeneration to a great extent. Moreover, MSCs-encapsulated FMs were more effective in shortening the regeneration period of the injured tissue of the rat VML, resulting in good myofibre orientation, while the Sham group resulted in incomplete repair with fibrotic scar tissue formations.

Context: The physical and mental demands of an elite football player are complex, which may explain why injuries are common in football. At elite level, muscle injuries of the lower-extremity are the most common among male football players, and the research hitherto is limited., Objective: To investigate whether personality traits affect the incidence of muscle injuries among male football players from the first league in Sweden., Design: Prospective cohort study., Participants: A male football team from the first league in Sweden was prospectively followed, in terms of muscle injuries of the lower-extremity during 8 seasons, between 2007 and 2015., Intervention: All muscle injuries included in this study were evaluated and diagnosed with ultrasonography. Players from the team filled out the Swedish Universities Scales of Personality questionnaire. Swedish Universities Scales of Personality questionnaire consists of 91 items and is divided into 13 categories., Main Outcome Measures: The raw values of each scale were linearly transformed to T scores, having a mean (SD) of 50 (10). All variables were summarized with standard descriptive statistics, such as frequency, mean, and SD. As data were of interval scale and no variable distribution was severely skewed, differences between noninjured players, rarely injured players, and frequently injured players were analyzed with 1-way analysis of variance with post hoc tests by Tukey honestly significant difference test., Results: No significant difference in personality traits were observed between noninjured players, rarely injured players, and frequently injured players regarding number of muscle injuries (P > .05). However, a trend (P = .07) was seen, where frequently injured players scored higher on stress susceptibility than rarely injured players., Conclusion: A player's stress susceptibility should be taken into consideration by the player, coaches, and medical staff when assessing the risk of a muscle injury. Also, preventive measures available for these players may need to be considered.

Sleep is crucial to improve athlete performance and their circadian rhythm, but sleep patterns may be disturbed because athletes participate in several competitions. In addition, intensive training programs can cause muscle pain and psychological stress in athletes, resulting in a lack of sleep. Sleep also plays a critical role in the recovery of muscle injury induced by exercise. The current study evaluated the effect of sleep deprivation on the recovery of muscle injury induced by high-intensity exercise in a mouse model. In this study, 28 mice were randomly assigned to four groups (N = 7): control (Control), exercise (EX), sleep deprivation (SD), and sleep deprivation with exercise (EX+SD). The mice from the EX and EX+SD groups were subjected to high-intensity swimming. The results showed that 72-h sleep deprivation increased food intake and reduced body weight. However, the manipulation of 8-week exercise and/or 72-h sleep deprivation did not have any effect in the elevated plus maze task and tail suspension test. Interestingly, the EX+SD group exhibited improved memory performance in the Morris water maze and impaired motor activity in the open field test. According to the TNF-α level and aspartate aminotransferase (AST), and creatine phosphokinase (CK) activities, only the EX+SD group exhibited muscle impairment. Overall, high-intensity exercise may cause muscle injury, and adequate sleep can recover muscle damage. However, sleep deprivation reduces protein synthesis, which decreases the ability to restore muscle damage and aggravates the harmful effect of high-intensity exercise., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Muscle and kidney injury in endurance athletes is worrying for health, and its relationship with physical external workload (eWL) needs to be explored. This study aimed to analyze which eWL indexes have more influence on muscle and kidney injury biomarkers. 20 well-trained trail runners (age = 38.95 ± 9.99 years) ran ~35.27 km (thermal-index = 23.2 ± 1.8 °C, cumulative-ascend = 1815 m) wearing inertial measurement units (IMU) in six different spots (malleolus peroneus [MP left /MP right ], vastus lateralis [VL left /VL right ], lumbar [L 1 -L 3 ], thoracic [T 2 -T 4 ]) for eWL measuring using a special suit. Muscle and kidney injury serum biomarkers (creatin-kinase [sCK], creatinine (sCr), ureic-nitrogen (sBUN), albumin [sALB]) were assessed pre-, -post 0h and post 24h . A principal component (PC) analysis was performed in each IMU spot to extract the main variables that could explain eWL variance. After extraction, PC factors were inputted in multiple regression analysis to explain biomarkers delta change percentage (Δ%). sCK, sCr, sBUN, sALB presented large differences ( p < 0.05) between measurements (pre < post 24h < post 0h ). PC's explained 77.5-86.5% of total eWL variance. sCK Δ% was predicted in 40 to 47% by L 1 -L 3 and MP left ; sCr Δ% in 27% to 45% by L 1 -L 3 and MP left ; and sBUN Δ% in 38%-40% by MP right and MP left . These findings could lead to a better comprehension of how eWL (impacts, player load and approximated entropy) could predict acute kidney and muscle injury. These findings support the new hypothesis of mechanical kidney injury during trail running based on L 1 -L 3 external workload data.

Idiopathic scoliosis (IS) is a disease with unknown etiology characterized by spinal rotation asymmetry. Reports describing the histochemical and pathological analyses of IS patients have shown that necrosis, fibrosis and fatty involution occurred on the apex paraspinal muscles. However, research on the changes in the paraspinal muscles of IS patients compared with those in matched controls is rare; thus, the basic mechanism of how paraspinal muscles are injured in IS patients is still unclear. In this study, we investigated the morphological changes of paraspinal muscles in the control group and IS patients, and the possible mechanisms were examined in vivo and in vitro . Increased myofiber necrosis was found on both sides of the apex paraspinal muscles of IS patients compared with those of the control group, and the number of TUNEL-positive apoptotic cells was also increased. Apoptosis signaling pathways, including pro-apoptosis proteins such as cleaved-caspase 3 and cytochrome c, were markedly upregulated, whereas the anti-apoptotic Bcl-2/Bax was significantly downregulated in IS patients compared with the control group. Moreover, PGC-1α and SOD1 were upregulated in accordance with the increased ROS production in IS patients. The distribution of myofiber types, as well as the mRNA levels of type IIa myofiber marker MYH2 and the important myogenesis regulator MYOG were remarkably changed in IS patients. In addition, C2C12 or human skeletal muscle mesenchymal progenitor cells treated with antimycin A in glucose-free and serum-free culture medium, which can activate oxidative stress and induce apoptosis, showed similar patterns of the changed distribution of myofiber types and downregulation of MYH2 and MYOG . Altogether, our study suggested that the extents of severe muscle injury and accumulated oxidative stress were increased in IS patients compared with the control group, and the abnormal myogenesis was also observed in IS patients. Since elevated oxidative stress can lead to apoptosis and the dysregulation of myogenesis in muscle cells, it may be associated with the pathological changes observed in IS patients and contribute to the development and progression of IS., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Background: The relationship between the tissue injury healing response and development of heterotopic ossification (HO) is poorly understood. Here we compare a rat blast model and human traumatized muscle from a blast injury to study the early signatures of osteogenesis and fibrosis during the formation of HO., Methods: Rat and human tissues were characterized using histology, scanning electron microscopy, immunohistochemistry, as well as gene and protein expression analysis. Additionally, animals and humans were assessed radiographically for HO formation following injury., Results: Markers of bone formation were dramatically increased in tissue samples from both humans and rats, and both displayed increased fibroproliferative regions within the injured tissues and elevated expression of markers of tissue fibrosis such as TGF-β1, Fibronectin, SMAD3 and PAI-1. Markers of inflammation and fibrosis (ACTA, TNFα, BMP1 and BMP3) were elevated at the RNA level in both rat and human samples. By day 42, bone formation in the rat blast model appeared similar in radiographs compared to human patients who progressed to develop post-traumatic HO., Conclusions: Our data demonstrates that a similar early fibrotic response is evident in both the rat blast model and the human tissues following a traumatic injury and demonstrates the relevance of this animal model for future translational studies.

Objective: The aim of this study was to assess muscle injury associated with upper and lower closed limb fracture using ultrasound, and to develop ultrasound classification criteria for muscle injury., Patients and Methods: Thirty patients with limb fracture and muscle injury participated in this study. Ultrasonography was used to assess muscle fibre, hematoma, vascular injury, and diameter growth rate. Injury was classified into three grades according to the ultrasound imaging: scores of less than, equal to, or greater than 9., Results: Of 30 patients, focal fibre rupture was observed in 11 cases; in 9 cases, the injured area exceeded 30% of the muscle area. Six patients had muscle hematoma (the largest reaching 39 mm); in 4 patients, the hematoma showed a honeycombed pattern. Vascular rupture was observed in 6 patients, of which 2 had decreased main arterial diameter and blood flow. The greatest increase in muscle thickness was 17 mm. Of all patients, 11 showed an increase in the diameter growth rate of the muscle exceeding 50%. In addition, among the 30 patients, 11 patients with scores ranging from 4 to 8 received conservative treatment; 9 patients with scores ranging from 10 to 14 received operative treatment; and 10 patients with scores equal to 9 received either conservative or operative treatment., Conclusions: Ultrasonography is useful for diagnosing muscle injury associated with closed limb fracture. The ultrasound classification criteria for muscle injury can be used to assess the severity of injury and guide the decision of treatment.

Early recovery from muscular injury is crucial for elite athletes. Hyperbaric oxygen therapy (HBOT) has been reported to be beneficial in terms of accelerating cell recovery and tissue repair, which are considered to be helpful for eliminating fatigue and recovering stamina. This study was performed to evaluate the efficacy of HBOT for exercise-related muscular injury. Forty-one athletes with exercise-related muscular injuries were recruited and randomized into an HBOT group and a control group. All participants received 10 sessions of either HBOT or placebo treatment. The brief pain inventory (BPI) was completed, and serum samples were analyzed. Data were collected before treatment (T1), at the end of the fifth treatment session (T2), at the end of the tenth treatment session (T3), and two weeks after T3 (T4). At T3, the HBOT group showed prominent reductions in the levels of creatine phosphokinase (CK), glutamic oxaloacetate transaminase (GOT), and myoglobin (MB), which lasted until T4. However, the control group did not present any statistical differences in levels from T1 to T4. In terms of pain intensity and interference, the HBOT group showed significant improvements at T3, while no improvements were observed in the control group. In conclusion, HBOT facilitates the early recovery of exercise-related muscular injury. This trial is registered with ISRCTN17817041.

Study of the influence of vibration oscillations of different frequency, amplitude and vibration acceleration on the structural and functional state and mechanisms of muscle tissue remodelling. An experimental study was conducted on sexually mature male rats. The rats of the four experimental groups were subjected to vertical vibration oscillations of 15, 25, 50 and 75 Hz, respectively. It has been established that pathological changes in muscle tissue in the form of different variants of damage and remodelling tend to increase, which correlates with the frequency of vibration, amplitude and vibration acceleration level, as in the 2nd group, where the maximum permissible vibration levels did not exceed the established allowable norms, and in other groups of animals, where the permissible levels of total vibration were exceeded. By increasing vibration acceleration for more than 1.25 m/s2 (0.13 g, frequency more than 25 Hz and amplitude of 2 mm), severe damages are observed in the form of alterative changes of muscle fibres with the disappearance of transverse strain, homogenization of sarcoplasm, fragmentation with dissociation fibres on separate beams, partial and subtotal myocytolysis, and necrosis of separate fibres. Inflammation is rapidly increasing with the increase in the frequency of vibration and the level of vibration acceleration for more than 5.0 m/s2 (0.51 g).

Competing Interests: Competing interests: None declared.

This chapter describes a protocol for the isolation of larval zebrafish muscle stem/progenitor cells by fluorescence-activated cell sorting (FACS). This method has been successfully applied to isolate pax3a expressing cells 3 days following needle stab skeletal muscle injury. The cell sorting strategy described here can easily be adapted to any cell type at embryonic or larval stages. RNA extracted from the sorted cells can be used for subsequent downstream applications such as quantitative PCR (qPCR), microarrays, or next generation sequencing.

Leukocyte populations quickly respond to tissue damage, but most leukocyte kinetic studies are not based on multiparameter flow cytometry. We systematically investigated several blood leukocyte populations after controlled tissue damage. 48 patients were assigned to either an anterior or posterolateral total hip arthroplasty. Peripheral blood was collected pre-operatively and at 2 h, 24 h, 48 h, 2 and 6 weeks postoperatively and assessed by flow cytometry for absolute counts of multiple leukocyte populations using standardized EuroFlow protocols. Absolute counts of leukocyte subsets differed significantly between consecutive time points. Neutrophils increased instantly after surgery, while most leukocyte subsets initially decreased, followed by increasing cell counts until 48 h. At two weeks all leukocyte counts were restored to pre-operative counts. Immune cell kinetics upon acute tissue damage exhibit reproducible patterns, which differ between the leukocyte subsets and with "opposite kinetics" among monocyte subsets. Flow cytometric leukocyte monitoring can be used to minimally invasively monitor tissue damage., (Copyright © 2018. Published by Elsevier Inc.)

Soccer is the most popular sport in the world and has the fourth highest number of sports injuries. Hip and groin injuries account for 14% of soccer injuries and can be difficult to recognize and treat as they often require a high level of suspicion and advanced imaging. Groin pain can be separated into 3 categories: (1) defined clinical entities for groin pain (adductor-related, iliopsoas-related, inguinal-related [sports hernias/athletic pubalgia], and pubic-related groin pain), (2) hip-related groin pain (hip morphologic abnormalities, labral tears, and chondral injuries), and (3) other causes of groin pain. Conservative approaches are typically the first line of treatment, but operative intervention has been reported to result in higher rates of return to sport in athletes with hip-related and inguinal-related groin pain injuries. In patients with concurrent hip-related and inguinal-related groin pain, the failure to recognize the relationship and treat both conditions may result in lower rates of return to sport. Preseason screening programs can identify high-risk athletes, who may benefit from a targeted prevention program. Further study on exercise therapy, early surgical intervention, and potential biologic intervention are needed to determine the most effective methods of preventing groin injuries in athletes., Competing Interests: Authors' Disclosure Statement: Dr. Gerhardt reports that he is a consultant for Arthrex, Ferring Pharmaceuticals, Stryker, and Medacta. The other authors report no actual or potential conflict of interest in relation to this article.

Macrophages play a very important role in the conduction of several regenerative processes mainly due to their plasticity and multiple functions. In the muscle repair process, while M1 macrophages regulate the inflammatory and proliferative phases, M2 (anti-inflammatory) macrophages direct the differentiation and remodelling phases, leading to tissue regeneration. The aim of this study was to evaluate the effect of red and near infrared (NIR) photobiomodulation (PBM) on macrophage phenotypes and correlate these findings with the repair process following acute muscle injury. Wistar rats were divided into 4 groups: control; muscle injury; muscle injury + red PBM; and muscle injury + NIR PBM. After 2, 4 and 7 days, the tibialis anterior muscle was processed for analysis. Macrophages phenotypic profile was evaluated by immunohistochemistry and correlated with the different stages of the skeletal muscle repair by the qualitative and quantitative morphological analysis as well as by the evaluation of IL-6, TNF-α and TGF-β mRNA expression. Photobiomodulation at both wavelengths was able to decrease the number of CD68 + (M1) macrophages 2 days after muscle injury and increase the number of CD163 + (M2) macrophages 7 days after injury. However, only NIR treatment was able to increase the number of CD206 + M2 macrophages (Day 2) and TGF-β mRNA expression (Day 2, 4 and 7), favouring the repair process more expressivelly. Treatment with PBM was able to modulate the inflammation phase, optimize the transition from the inflammatory to the regeneration phase (mainly with NIR light) and improve the final step of regeneration, enhancing tissue repair., (© 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

Sport-related injury patterns among Para athletes have been described with increasing frequency. This review summarizes musculoskeletal injuries in Para athletes. Seated Para athletes sustain upper extremity injuries more commonly; ambulant Para athletes frequently sustain lower extremity injuries. The upper extremity is the most commonly injured anatomic area in all Para athletes, unlike able-bodied athletes. Advanced age and spinal cord injury may increase the risk of upper extremity injury. Injury data for recreational and youth Para athletes are sparse. Summarizing current injury epidemiology data may help to accelerate the development of injury prevention strategies and lifetime injury models for Para athletes., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Competitive sports yield high demands on the musculoskeletal system, accordingly muscle injuries are a common complication. Early imaging clarification of the muscles in cases of a trauma is essential in order to define the exact location of the lesion, the affected muscles, the extent and the degree of the injury as well as to define possible concomitant complications. In the case of a professional athlete, the assessment made by MRI is important for defining the individually required resting period for a riskless resumption of the sporting activities.

Clinical/methodical Issue: Muscular injuries represent the most common musculoskeletal lesions. Especially in professional athletes an imaging clarification is essential in order to define the exact location of the lesion, the affected muscles, the extent and degree of the injury as well as to define possible concomitant complications. The best possible therapy can be initiated and a necessary rest period for a low risk resumption of sporting activity can be individually specified., Standard Radiological Methods/methodical Innovations: Due to technical improvements, for example mobile devices and thus increased rapid availability as well as relative cost-effectiveness compared to other modalities, the imaging evaluation of muscle injury would nowadays be unthinkable without ultrasound., Performance: The article discusses general prerequisites for the performance of muscle ultrasound as well as a standardized examination algorithm of muscle injuries beginning with general and leading to special tips and tricks., Achievements/practical Recommendations: Despite the known investigator dependence, ultrasound enables a reliable and unerring imaging clarification of muscle injuries. For this reason, ultrasound should be considered as the first-line diagnostic imaging modality when dealing with muscle trauma.

Introduction: The use of intranasal fentanyl as an alternative type of analgesia has been shown to be effective in paediatric populations and prehospital settings. There are a limited number of studies on the use of intranasal fentanyl in adult patients in emergency settings., Methods: An open-label study was conducted to evaluate the effectiveness of the addition of 1.5 mcg/kg intranasal fentanyl to 2 mg/kg intravenous tramadol (fentanyl + tramadol arm, n = 10) as compared to the administration of 2 mg/kg intravenous tramadol alone (tramadol-only arm, n = 10) in adult patients with moderate to severe pain due to acute musculoskeletal injuries., Results: When analysed using the independent t-test, the difference between the mean visual analogue scale scores pre-intervention and ten minutes post-intervention was 29.8 ± 8.4 mm in the fentanyl + tramadol arm and 19.6 ± 9.7 mm in the tramadol-only arm (t[18] = 2.515, p = 0.022, 95% confidence interval 1.68-18.72 mm). A statistically significant, albeit transient, reduction in the ten-minute post-intervention mean arterial pressure was noted in the fentanyl + tramadol arm as compared to the tramadol-only arm (13.35 mmHg vs. 7.65 mmHg; using Mann-Whitney U test with U-value 21.5, p = 0.029, r = 0.48). There was a higher incidence of transient dizziness ten minutes after intervention among the patients in the fentanyl + tramadol arm., Conclusion: Although effective, intranasal fentanyl may not be appropriate for routine use in adult patients, as it could result in a significant reduction in blood pressure., (Copyright: © Singapore Medical Association)

Ultrasonography is a reliable diagnostic modality for muscle and tendon injuries, but it has been challenging to find right diagnosis of minor musculoskeletal injuries by conventional ultrasonographic imaging. A large amount of hydrogen peroxide (H 2 O 2 ) are known to be generated during tissue damages such as mechanical injury and therefore H 2 O 2 holds great potential as a diagnostic and therapeutic marker for mechanical injuries in the musculoskeletal system. We previously developed poly(vanillyl alcohol- co -oxalate) (PVAX), which rapidly scavenges H 2 O 2 and exerts antioxidant and anti-inflammatory activity in H 2 O 2 -associated diseases. Based on the notion that PVAX nanoparticles generate CO 2 bubbles through H 2 O 2 -triggered hydrolysis, we postulated that PVAX nanoparticles could serve as ultrasonographic contrast agents and therapeutic agents for musculoskeletal injuries associated with overproduction of H 2 O 2 . In the agarose gel phantom study, PVAX nanoparticles continuously generated CO 2 bubbles to enhance ultrasonographic echogenicity significantly. Contusion injury significantly elevated the level of H 2 O 2 in skeletal muscles and Achilles tendons. Upon intramuscular injection, PVAX nanoparticles significantly elevated the ultrasound contrast and suppressed inflammation and apoptosis in the contusion injury of musculoskeletal systems. We anticipate that PVAX nanoparticles hold great translational potential as theranostic agents for musculoskeletal injuries., Competing Interests: Competing Interests: The authors have declared that no competing interest exists.

Sport-related muscle injury classifications are based basically on imaging criteria such as ultrasound (US) and magnetic resonance imaging (MRI) without consensus because of a lack of clinical prognostics for return-to-play (RTP), which is conditioned upon the severity of the injury, and this in turn with the muscle gap (muscular fibers retraction). Recently, Futbol Club Barcelona's medical department proposed a new muscle injury classification in which muscle gap plays an important role, with the drawback that it is not always possible to identify by MRI. Localized bioimpedance measurement (L-BIA) has emerged as a non-invasive technique for supporting US and MRI to quantify the disrupted soft tissue structure in injured muscles., Objective: To correlate the severity of the injury according to the gap with the RTP, through the percent of change in resistance (R), reactance (Xc) and phase-angle (PA) by L-BIA measurements in 22 muscle injuries., Main Results: After grouping the data according to the muscle gap (by MRI exam), there were significant differences in R between grade 1 and grade 2f (myotendinous or myofascial muscle injury with feather-like appearance), as well as between grade 2f and grade 2g (myotendinous or myofascial muscle injury with feather and gap). The Xc and PA values decrease significantly between each grade (i.e. 1 versus 2f, 1 versus 2g and 2f versus 2g). In addition, the severity of the muscle gap adversely affected the RTP with significant differences observed between 1 and 2g as well as between 2f and 2g., Significance: These results show that L-BIA could aid MRI and US in identifying the severity of an injured muscle according to muscle gap and therefore to accurately predict the RTP.

Background: Sports concussion is a risk for players involved in high impact, collision sports. Post-concussion, the majority of symptoms subside within 7-10 days, but can persist in 10-20% of athletes. Understanding the effects of sports concussion on sensorimotor systems could inform physiotherapy treatment., Objective: To explore changes in sensorimotor function in the acute phase following sports concussion., Design: Prospective cohort study., Methods: Fifty-four players from elite rugby union and league teams were assessed at the start of the playing season. Players who sustained a concussion were assessed three to five days later. Measures included assessments of balance (sway velocity), vestibular system function (vestibular ocular reflex gain; right-left asymmetry), cervical proprioception (joint position error) and trunk muscle size and function., Results: During the playing season, 14 post-concussion assessments were performed within 3-5 days of injury. Significantly decreased sway velocity and increased size/contraction of trunk muscles, were identified. Whilst not significant overall, large inter-individual variation of test results for cervical proprioception and the vestibular system was observed., Limitations: The number of players who sustained a concussion was not large, but numbers were comparable with other studies in this field. There was missing baseline data for vestibular and cervical proprioception testing for some players., Conclusions: Preliminary findings post-concussion suggest an altered balance strategy and trunk muscle control with splinting/over-holding requiring consideration as part of the development of appropriate physiotherapy management strategies., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Although long non-coding RNAs (lncRNAs) are non-protein-coding transcripts by definition, recent studies have shown that a fraction of putative small open reading frames within lncRNAs are translated. However, the biological significance of these hidden polypeptides is still unclear. Here we identify and functionally characterize a novel polypeptide encoded by the lncRNA LINC00961. This polypeptide is conserved between human and mouse, is localized to the late endosome/lysosome and interacts with the lysosomal v-ATPase to negatively regulate mTORC1 activation. This regulation of mTORC1 is specific to activation of mTORC1 by amino acid stimulation, rather than by growth factors. Hence, we termed this polypeptide 'small regulatory polypeptide of amino acid response' (SPAR). We show that the SPAR-encoding lncRNA is highly expressed in a subset of tissues and use CRISPR/Cas9 engineering to develop a SPAR-polypeptide-specific knockout mouse while maintaining expression of the host lncRNA. We find that the SPAR-encoding lncRNA is downregulated in skeletal muscle upon acute injury, and using this in vivo model we establish that SPAR downregulation enables efficient activation of mTORC1 and promotes muscle regeneration. Our data provide a mechanism by which mTORC1 activation may be finely regulated in a tissue-specific manner in response to injury, and a paradigm by which lncRNAs encoding small polypeptides can modulate general biological pathways and processes to facilitate tissue-specific requirements, consistent with their restricted and highly regulated expression profile.

Objective: To observe the effect of electroacupuncture (EA) serum on proliferation of multifidus muscle sa-tellite cells (SCs) and expression of paired box transcription factor Pax-7, MyoD and protein kinase B (PKB or Akt) proteins of SCs, so as to explore its underlying mechanism in promoting repair of multifidus muscles., Methods: Thirty-two SD rats were randomly assigned to control, model, EA-Weizhong (BL 40) and EA-Shenshu (BL 23) groups. The multifidus muscle injury (MFMI) model was established by injection of 0.5% bupivacaine hydrochloride (400 μL) into the bilateral L 4 -L 5 paravertebral muscles (4 points, 100 μL for each point). EA stimulation was separately applied to bilateral BL 40 and BL 23 for 20 min, once daily, 4 days altogether. Blood samples of the abdominal artery of rats in the above mentioned 4 groups were separately collected for extracting serum, followed by deactivation and filtration, and then were respectively applied to the Dulbecco's Modified Eagle Media (DMEM) culturing each multifidus muscle SCs of the normal serum, model serum, EA-BL 40 serum and EA-BL 40 serum+LY 294002 (an inhibitor of phosphotidylinsitol-3-kinase, PI 3 K), EA-BL 23 serum and EA-BL 23 serum+LY 294002 groups for ana-lyzing the impact of EA serum on the proliferation state of SCs by Cell Counting Kit-8 (CCK-8) and 5-Ethynyl-2'-deoxyuridine (EdU) methods, respectively. The expression of Pax-7, MyoD and phosphorylated (p)-Akt proteins of the cultured SCs was detected for characterization of SCs by Western blot., Results: Compared with the normal serum group, the proliferation levels (detected by both CCK-8- and EdU) and the expression levels of MyoD and p-Akt proteins of SCs in the model serum group were significantly increased ( P <0.05, P <0.01), while in comparison with the model serum group, the proliferation and expression levels of MyoD and p-Akt proteins of SCs were further significantly increased in both EA-BL 23 and EA-BL 40 serum groups ( P <0.01, P <0.05), but not in the EA-BL 40 serum+LY 294002 and EA-BL 23 serum+LY 294002 groups ( P >0.05), suggesting an involvement of PI 3 K in the proliferation of SCs. No marked differences were found in the proliferation levels between the EA-BL 23 and EA-BL 40 serum groups and in the expression levels of Pax-7 proteins among the 6 serum groups ( P >0.05)., Conclusions: Both EA-BL 40 and EA-BL 23 serum can promote proliferation of multifidus muscle SCs, which may contribute to the effect of EA intervention in promoting repair of the injured muscle, partially by way of Akt/PI 3 K signaling.

PAS domain containing protein kinase (Pask) is an evolutionarily conserved protein kinase implicated in energy homeostasis and metabolic regulation across eukaryotic species. We now describe an unexpected role of Pask in promoting the differentiation of myogenic progenitor cells, embryonic stem cells and adipogenic progenitor cells. This function of Pask is dependent upon its ability to phosphorylate Wdr5, a member of several protein complexes including those that catalyze histone H3 Lysine 4 trimethylation (H3K4me3) during transcriptional activation. Our findings suggest that, during myoblast differentiation, Pask stimulates the conversion of repressive H3K4me1 to activating H3K4me3 marks on the promoter of the differentiation gene myogenin ( Myog ) via Wdr5 phosphorylation. This enhances accessibility of the MyoD transcription factor and enables transcriptional activation of the Myog promoter to initiate muscle differentiation. Thus, as an upstream kinase of Wdr5, Pask integrates signaling cues with the transcriptional network to regulate the differentiation of progenitor cells., Competing Interests: The authors declare that no competing interests exist.

Background: It is well known that platelet-rich plasma (PRP) preparations are not the same and that not all preparations include white blood cells, but the part that leukocytes play on the healing role of PRP is still unknown., Purpose: The primary aim of this study was to evaluate the influence of leukocytes in different PRP preparations with a special emphasis on growth factor concentrations. The secondary aim was to evaluate the influence of PRP on muscle healing., Study Design: Controlled laboratory study., Methods: Two PRP preparation procedures were evaluated. Blood fractions were stained with Rapid Panoptic, and growth factors (transforming growth factor beta 1 [TGF-β1], vascular endothelial growth factor [VEGF], insulin-like growth factor [IGF], epidermal growth factor [EGF], hepatocyte growth factor [HGF], and platelet-derived growth factor [PDGF]) were quantified by enzyme-linked immunosorbent assay. Western blotting analysis was performed for Fms-related tyrosine kinase 1 (Flt-1). A muscle contusion injury was created and treated with PRP at different time points., Results: Leukocytes were the main source of VEGF, and all other growth factors measured had a higher concentration in the preparations that included the buffy coat and consequently had a higher concentration of white blood cells. Flt-1 was also found in platelet-poor plasma (PPP). There were higher concentrations of PDGF and HGF in the preparations that encompassed the buffy coat. A PRP injection 7 days after the injury provided significantly increased exercise performance and decreased the fibrotic area when compared with other PRP-treated groups., Conclusion: VEGF is only present in PRP's buffy coat, while Flt-1 is present in PPP. A PRP injection 7 days after an injury resulted in improved exercise performance., Clinical Relevance: The presence of Flt-1 in PRP provides yet another explanation for results described in the literature after a PRP injection. This information is relevant for selecting the best PRP for each type of injury., (© 2016 The Author(s).)

The lateral support of the vaginal wall depends on the integrity of the paravaginal section of the visceral pelvic fascia, levator ani, and their connection. Various defects of the muscle and fascia can result in identical clinical findings-ie, the descent of the lateral vaginal sulcus. In this study, we created a realistic scheme for classifying paravaginal defects, based on the complex relationship of the pelvic fascia with the levator ani. Surgical observations, cadaver examinations, and a complex magnetic resonance imaging (MRI)-based 3-dimensional (3D) model were used to analyze the spatial relationships of normal and defective anatomy of the female pelvic floor. Descent of the lateral vaginal sulcus can result from a defect in the paravaginal visceral pelvic fascia, levator ani, or both. The fascial defect can be partial or complete, and the muscle defect can vary in location. A detailed illustrated classification is presented. We present a new model of the pathology that underlies a common clinical finding., (© 2016 Wiley Periodicals, Inc.)

Objective: To observe the intervention effect of electroacupuncture (EA) at "Weizhong" (BL 40) on rats with bupivacaine-induced multifidus muscle injury, so as to explore the action mechanism., Methods: A total of 72 rats were randomly divided into a control group, a model group, a Weizhong group and a Shenshu group, 18 rats in each group. Each group was again randomly divided into a 4-day subgroup, a 7-day subgroup and a 14-day subgroup, 6 rats in each subgroup. Rats in the model group, Weizhong group and Shenshu group were treated with intramuscular injection of 0.5% bupivacaine (BPVC) to establish the model of multifidus muscle injury. Rats in the Weizhong group and Shenshu group were treated with EA at "Weizhong" (BL 40) and "Shenshu" (BL 23), 20 min per treatment, once a day. Each subgroup was treated for 4 days, 7 days and 14 days respectively. Rats in the control group and model group were treated with immobilization. The morphology and cross sectional area (CSA) changes of multifidus with HE and Masson staining at different time points were observed; the expression of insulin like growth factor 1 (IGF-1) and myogenic differentiation antigen (MyoD) was measured by immunohistochemical method., Results: After the modeling, there were significant morphology changes of multifidus at different time points, which was not fully recovered after 14 days. The morphological observation in the Weizhong group and Shenshu group was superior to that in the model group. At 7th day, the CSA in the Weizhong group was higher than that in the model group (P < 0.05); at 14th day, the CSA in the Weizhong group and Shenshu group was higher than that in the model group (P < 0.01, P < 0.05). At 4th day and 7th day, the expression of IGF-1 in the model group was higher than that in the control group (both P < 0.01); at 4th day, that in the Weizhong group was higher than that in the model group (P < 0.01), and that in the Weizhong group was higher than that in the Shenshu group (P < 0.05), and that in the Shenshu group was as higher than that in the model group (P < 0.05); at 14th day, that in the Shenshu group was higher than that in the model and Weizhong group (P < 0.01). At 4th day, the expression of MyoD in the Weizhong group and Shenshu group was higher than that in the model group (P < 0.01), which was more significant in the Weizhong group (P < 0.01)., Conclusion: Electroacupuncture at "Weizhong" (BL 40) and "Shenshu" (BL 23) can both promote the regeneration of multifidus muscle injury. EA at "Weizhong" (BL 40) has a better effect at early phase, which may be related to the up-regulation of IGF-1 and MyoD and the completion of the proliferation of myoblast in advance.

This prospective cohort study investigated the influence of an artificial playing surface on injury risk and perceptions of muscle soreness in elite English Premiership Rugby Union players. Time loss (from 39.5 matches) and abrasion (from 27 matches) injury risk was compared between matches played on artificial turf and natural grass. Muscle soreness was reported over the 4 days following one match played on each surface by 95 visiting players (i.e., normally play on natural grass surfaces). There was a likely trivial difference in the overall injury burden relating to time-loss injuries between playing surfaces [rate ratio = 1.01, 90% confidence interval (CI): 0.73-1.38]. Abrasions were substantially more common on artificial turf (rate ratio = 7.92, 90% CI: 4.39-14.28), although the majority of these were minor and only two resulted in any reported time loss. Muscle soreness was consistently higher over the 4 days following a match on artificial turf in comparison with natural grass, although the magnitude of this effect was small (effect sizes ranging from 0.26 to 0.40). These results suggest that overall injury risk is similar for the two playing surfaces, but further surveillance is required before inferences regarding specific injury diagnoses and smaller differences in overall injury risk can be made., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Extensor mechanism injuries in total knee arthroplasty include disruption of the quadriceps tendon, disruption of the patellar tendon, and/or patellar fractures. While these injuries are rare, they are a devastating complication to manage. This review summarizes the anatomy of the extensor mechanism, risk factors for extensor mechanism injuries, and the prevalence and diagnosis of extensor mechanism injuries. In addition, this review outlines non-operative and operative management options. A new surgical approach for the reconstruction and augmentation of the extensor mechanism with the use of a synthetic mesh is described in detail. In multiple publications and in our own experience this newly developed technique shows promising results.

Autogenic fat graft usually suffers from degeneration and volume shrinkage in volume reconstruction applications. How to maintain graft viability and graft volume is an essential consideration in reconstruction therapies. In this presented investigation, a new fat graft transplantation method was developed aiming to improve long term graft viability and volume reconstruction effect by incorporation of hydrogel. The harvested fat graft is dissociated into small fragments and incorporated into a collagen based hydrogel to form a hydrogel/fat graft complex for volume reconstruction purpose. In vitro results indicate that the collagen based hydrogel can significantly improve the survivability of cells inside isolated graft. In a 6-month investigation on artificial created defect model, this hydrogel/fat graft complex filler has demonstrated the ability of promoting fat pad formation inside the targeted defect area. The newly generated fat pad can cover the whole defect and restore its original dimension in 6-month time point. Compared to simple fat transplantation, this hydrogel/fat graft complex system provides much improvement on long term volume restoration effect against degeneration and volume shrinkage. One notable effect is that there is continuous proliferation of adipose tissue throughout the 6-month period. In summary, the hydrogel/fat graft system presented in this investigation demonstrated a better and more significant effect on volume reconstruction in large sized volume defect than simple fat transplantation.

Objective: To assess workload-related risk factors for injuries to particular tissue types in cricket fast bowlers., Design: 235 fast bowlers who bowled in 14600 player innings over a period of 15 years were followed in a prospective cohort risk factor study to compare overs bowled in each match (including preceding workload patterns) and injury risk in the 3-4 weeks subsequent to the match. Injuries were categorised according to the affected tissue type as either: bone stress, tendon injuries, muscle strain or joint injuries. Workload risk factors were examined using binomial logistic regression multivariate analysis, with a forward stepwise procedure requiring a significance of <0.05., Results: High acute match workload and high previous season workload were risk factors for tendon injuries, but high medium term (3-month workload) was protective. For bone stress injuries, high medium term workload and low career workload were risk factors. For joint injuries, high previous season and career workload were risk factors. There was little relationship between muscle injury and workload although high previous season workload was slightly protective., Conclusions: The level of injury risk for some tissue types varies in response to preceding fast bowling workload, with tendon injuries most affected by workload patterns. Workload planning may need to be individualised, depending on individual susceptibility to various injury types. This study supports the theory that tendons are at lowest risk with consistent workloads and susceptible to injury with sudden upgrades in workload. Gradual upgrades are recommended, particularly at the start of a bowler's career to reduce the risk of bone stress injury., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)