Isokinetic trunk flexion-extension protocol to assess trunk muscle strength and endurance:Reliability,learning effect,and sex differences

Purpose:The purpose of this study was to examine the reliability and the learning effect of an isokinetic trunk flexion-extension protocol designed to simultaneously assess trunk muscle strength and endurance.In addition,the effect of the participants’sex on the reliability data was examined.Methods:Fifty-seven healthy and physically active young men(n=28)and women(n=29)performed the isokinetic protocol 5 times,separated by a week between each of the first 4 sessions and by a month between the last 2 sessions.The protocol consisted of performing 4 trials of 15 maximum flexion-extension concentric exertions at 120°/s(range of trunk motion=50°).The absolute and relative peak torque and total work were calculated to assess trunk flexion and extension strength.In addition,endurance ratio,modified endurance ratio,fatigue final ratio,recovery ratio,and modified recovery ratio variables were used for the assessment of trunk muscle endurance in both directions.Results:Regarding the absolute reliability,no relevant changes were found between paired-comparison sessions for most strength and endurance variables,except for total work and relative total work variables in the flexion movement in both sexes.In addition,the typical error of the isokinetic variables was lower than 10%in both males and females,and minimum detectable changes ranged from 7%to 20%,with a tendency to be higher in females and in endurance variables.The strength variables showed high-to-excellent intraclass correlation coefficients(ICCs;>0.74);however,for the endurance variables only the endurance ratio and the modified endurance ratio obtained moderate-to-high ICC values(0.57<ICC<0.82).In addition,the analysis of the variance reported no significant differences between consecutive pairs of sessions for most variables in both sexes.Conclusion:Overall,these findings provide clinicians,trainers,and researchers with a 10-min single-session protocol to perform a reliable muscle strength and endurance evaluation of trunk flexor and extensor muscles,all within the same protocol.

Effect of minimal shoes and slope on vertical and leg stiffness during running

Purpose： This study was designed to characterize and compare the vertical（kvert） and leg（kleg） stiffness measured during running in two different footwear conditions on negative, level, and positive slopes, using kinematic data only.Methods： Fourteen male recreational runners（age 23.4 4.4 years, height 177.5 5.2 cm, and body mass 69.5 5.3 kg） were tested on 2separate days within 1 week. At each session, subjects ran seven 5-min trials on a treadmill at 10 km/h, interspersed with 5 min of sitting passive recovery. Each trial was performed on a different slope gradient, ranging from 8%（downhill） to t8%（uphill）, assigned in a random order.Furthermore, each subject ran one 5-min trial wearing minimal shoes（MS） and the subsequent trial wearing traditional shoes（TS） in a counterbalanced randomized order ensuring that each slope was ran once in MS and once in TS. Kinematic data were collected using a photocell measuring system and high-speed video camera, with kvertand klegstiffness being calculated from these data.Results： Leg compression, contact times, and vertical displacement of the center of mass during running were significantly smaller in MS compared to TS across all slopes. In the two footwear conditions, step frequency significantly increased with a（positive） increase in slope.Kinematic analyses indicated that klegwas greater when running in MS than TS and this between-footwear difference remained similar across slopes. On the contrary, kvertdid not change on the basis of footwear, but increased with positive increases in slope.Conclusion： This study showed that kvertand klegduring running respond differently to change in footwear and/or slope. These two stiffness measures can hence provide a unique insight on the biomechanical adaptations of running under varying conditions and their respective quantification may assist in furthering our understanding of training, performance, and/or injury in this sport.

The influence of physiobiomechanical parameters,technical aspects of shooting,and psychophysiological factors on biathlon performance:A review

The biathlon, an Olympic sporting discipline that combines cross-country skiing with rifle marksmanship, entails considerable physiological demands, as well as fine motor control while shooting after intense exercise and under mental pressure. Although much of our knowledge about cross-country skiing is probably also applicable to the biathlon, carrying the rifle and shooting under stress make this discipline somewhat unique. The present review summarizes and examines the scientific literature related to biathlon performance, with a focus on physiological and biomechanical factors and shooting technique, as well as psychophysiological aspects of shooting performance. We conclude with suggestions for future research designed to extend our knowledge about the biathlon, which is presently quite limited.2018 Published by Elsevier B.V. on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license. （http：//creativecommons.org/licenses/by-nc-nd/4.0/）.

Maximizing recovery time between knock-out races improves sprint cross-country skiing performance

Background:In a sprint cross-country(XC)ski competition,the difference in recovery times separating the first and the second semi-final(SF)heats from the final(F)may affect performance.The aim of the current study was to compare the effects of longer vs.shorter recovery periods prescribed between the 3 knock-out races of a simulated sprint XC ski competition involving a prologue(P),quarter-final(QF),SF,and F.Methods:Eleven well-trained XC ski athletes completed 2 simulated sprint XC ski competitions on a treadmill involving 4×883-m roller-ski bouts at a 4°incline using the gear 3 ski-skating sub-technique.The first 3 bouts were completed at a fixed speed(PFIX,QFFIX,and SFFIX)corresponding to~96%of each individual’s previously determined maximal effort.The final bout was performed as a self-paced sprint time trial(FSTT).Test conditions differed by the time durations prescribed between the QFFIX,SFFIX,and FSTT,which simulated real-world XC ski competition conditions using maximum(MAX-REC)or minimum(MIN-REC)recovery periods.Results:The FSTT was completed 5.4±5.5 s faster(p=0.009)during MAX-REC(179.2±18.1 s)compared to MIN-REC(184.6±20.0 s),and this was linked to a significantly higher power output(p=0.010)and total metabolic rate(p=0.009).The pre FSTT blood lactate(BLa)concentration was significantly lower during MAX-REC compared to MIN-REC(2.5±0.8 mmol/L vs.3.6±1.6 mmol/L,respectively;p=0.027),and the pre-to-post FSTT increase in BLa was greater(8.8±2.1 mmol/L vs.7.1±2.3 mmol/L,respectively;p=0.024).No other differences for MAX-REC vs.MIN-REC reached significance(p>0.05).Conclusion:Performance in a group of well-trained XC skiers is negatively affected when recovery times between sprint heats are minimized which,in competition conditions,would occur when selecting the last QF heat.This result is combined with a higher pre-race BLa concentration and a reduced rise in BLa concentration under shorter recovery conditions.These findings may help inform decision making when XC skiers are faced with selecting a QF heat within a sprint competition.

Indirect printing of hierarchical patient-specific scaffolds for meniscus tissue engineering

The complex meniscus tissue plays a critical role in the knee. The high susceptibility to injury has led to an intense pursuit for better tissue engineering regenerative strategies, where scaffolds play a major role. In this study, indirect printed hierarchical multilayered sca ffolds composed by a silk fibroin (SF) upper layer and an 80/20 (w/w) ratio of SF/ionic-doped β-tricalcium phosphate (TCP) bottom layer were developed. Furthermore, a comparative analysis between two types of sca ffolds pro- duced using di fferent SF concentrations, i.e., 8% (w/v) (Hi8) and 16% (w/v) (Hi16) was performed. In terms of architecture and morphology, the produced sca ffolds presented homogeneous porosity in both layers and no di fferences were observed when comparing both sca ffolds. A decrease in terms of mechanical performance of the sca ffolds was observed when SF concentration decreased from 16 to 8% (w/v). Hi16 revealed a static compressive modulus of 0.66 ± 0.05 MPa and dynamical mechanical properties ranging from 2.17 ± 0.25 to 3.19 ± 0.38 MPa. By its turn, Hi8 presented a compressive modulus of 0.27 ± 0.08 MPa and dynamical mechanical properties ranging from 1.03 ± 0.08 MPa to 1.56 ± 0.13 MPa. In vitro bioactivity studies showed formation of apatite crystals onto the surface of Hi8 and Hi16 bottom layers. Human meniscus cells (hMCs) and human primary osteoblasts were cultured separately onto the top layer (SF8 and SF16) and bottom layer (SF8/TCP and SF16/TCP) of the hierarchical sca ffolds Hi8 and Hi16, respectively. Both cell types showed good adhesion and proliferation as denoted by the live/dead staining, Alamar Blue assay and DNA quanti fication analysis. Subcutaneous implantation in mice revealed weak in flammation and sca ffold’s integrity. The hierarchical indirect printed SF sca ffolds can be promising candidate for meniscus TE sca ffolding applications due their suitable mechanical properties, good biological performance and possibility of being applied in a patient-speci fic approach.

Anterior cruciate ligament reconstruction using a double bundle hamstring autograft configuration in patients under 30 years

BACKGROUND Anterior cruciate ligament reconstruction(ACLR)has a high incidence of re-tear in younger patients.Despite comparable functional outcomes,the incidence of retear using single and double bundle ACLR methods has not been well reported.AIM To hypothesize that double bundle hamstring ACLR has a lower graft rupture rate compared with single bundle hamstring ACLR grafts in young patients.METHODS One hundred and twelve patients<30 years of age at the time of primary double bundle ACLR were eligible for study participation.91(81.3%)could be contacted,with a mean age of 20.4 years(range 13-29)and mean post-operative follow-up time of 59 mo(range 25-107).Telephone questionnaires evaluated the incidence(and timing)of subsequent re-tear and contralateral ACL tear,further surgeries,incidence and time to return to sport,and patient satisfaction.RESULTS Of the 91 patients,there were 6(6.6%,95%CI:1.4-11.7)ACL graft re-ruptures,with a mean time to re-rupture of 28 mo(range 12-84).Fourteen patients(15.4%)experienced a contralateral ACL rupture and 14 patients(15.4%)required further surgery to their ipsilateral knee.fifty patients(54.9%)returned to pre-injury level of sport.Of those<20 years(n=45),4 patients(8.9%,95%CI:0.4-17.3)experienced a re-rupture,with mean time to re-injury 15 mo(range 12-24).Comparative analysis with existing literature and revealed a non-significant Chisquared statistic of 2.348(P=0.125).CONCLUSION A trend existed toward lower graft rupture rates in young patients undergoing double bundle ACLR utilizing a hamstring autograft,compared with rates reported after single bundle ACLR.

Pacing and predictors of performance during cross-country skiing races:A systematic review

Background： Cross-country skiing （XCS） racing, a popular international winter sport, is complex and challenging from physical, technical, and tactical perspectives. Despite the vast amount of research focusing on this sport, no review has yet addressed the pacing strategies of elite XCS racers or the factors that influence their performance. The aim was to review the scientific literature in an attempt to determine the effects of pacing strategy on the performance of elite XCS racers. Methods： Four electronic databases were searched using relevant subject headings and keywords. Only original research articles published in peerreviewed journals and the English language and addressing performance, biomechanics, physiology, and anthropometry of XCS racers were reviewed. Results： All 27 included articles applied correlative designs to study the effectiveness of different pacing strategies. None of the articles involved the use of an experimental design. Furthermore, potential changes in external conditions （e.g.,weather, ski properties） were not taken into consideration. A comparable number of studies focused on the skating or classical technique. In most cases, positive pacing was observed, with certain indications that higher-level athletes and those with more endurance and strength utilized a more even pacing strategy. The ability to achieve and maintain a long cycle length on all types of terrain was an important determinant of performance in all of the included studies, which was not the case for cycle rate. In general, uphill performance was closely related to overall race performance, with uphill performance being most closely correlated to the success of female skiers and performance on flat terrain being more important for male skiers. Moreover, pacing was coupled to the selection and distribution of technique during a race, with faster skiers employing more double poling and kick double poling, less diagonal stride, and more V2 （double dance） than V1 （single dance） skating across a race. Conclusion： We propose that skiers at all levels can improve their performance with more specific training in techniques （i.e., maintaining long cycles without compromising cycle rate and selecting appropriate techniques） in combination with training for endurance and more strength. Furthermore, we would advise less experienced skiers and/or those with lower levels of performance to apply a more even pacing strategy rather than a positive one （i.e., starting the race too fast）.2018 Published by Elsevier B.V. on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license. （http：//creativecommons.org/licenses/by-nc-nd/4.0/）.

Renal function and physical fitness after 12-mo supervised training in kidney transplant recipients

AIM To evaluate the effect of a 12-mo supervised aerobic and resistance training, on renal function and exercise capacity compared to usual care recommendations.METHODS Ninety-nine kidney transplant recipients(KTRs) were assigned to interventional exercise(Group A; n = 52) and a usual care cohort(Group B; n = 47). Blood and urine chemistry, exercise capacity, muscular strength, anthropometric measures and health-related quality of life(HRQo L) were assessed at baseline, and after 6 and 12 mo. Group A underwent a supervised training three times per week for 12 mo. Group B received only general recommendations about home-based physical activities.RESULTS Eighty-five KTRs completed the study(Group A, n = 44; Group B, n = 41). After 12 mo, renal function remained stable in both groups. Group A significantly increased maximum workload(+13 W, P = 0.0003), V'O2 peak(+3.1 mL/kg per minute, P = 0.0099), muscular strength in plantar flexor(+12 kg, P = 0.0368), height in the countermovement jump(+1.9 cm, P = 0.0293) and decreased in Body Mass Index(-0.5 kg/m^2, P = 0.0013). HRQo L significantly improved in physical function(P = 0.0019), physical-role limitations(P = 0.0321) and social functioning scales(P = 0.0346). Noimprovements were found in Group B.CONCLUSION Twelve-month of supervised aerobic and resistance training improves the physiological variables related to physical fitness and cardiovascular risks without consequences on renal function. Recommendations alone are not sufficient to induce changes in exercise capacity of KTRs. Our study is an example of collaborative working between transplant centres, sports medicine and exercise facilities.

Biomechanical analysis of the "running" vs. "conventional" diagonal stride uphill techniques as performed by elite cross-country skiers

Purpose:This study aimed to compare biomechanical aspects of a novel"running"diagonal stride(DSRUN)with"conventional"diagonal stride(DSCONV)skiing techniques performed at high speed.Methods:Ten elite Italian male junior cross-country skiers skied on a treadmill at 10 km/h and at a 10°incline utilizing both variants of the diagonal stride technique.The 3-dimensional kinematics of the body,poles,and roller skis;the force exerted through the poles and foot plantar surfaces;and the angular motion of the leg joints were determined.Results:Compared to DSCONV,DSRUN demonstrated shorter cycle times(1.05±0.05 s vs.0.75±0.03 s(mean±SD),p<0.001)due to a shorter rolling phase(0.40±0.04 s vs.0.09±0.04 s,p<0.001);greater force applied perpendicularly to the roller skis when they had stopped rolling forward(413±190 N vs.890±170 N,p<0.001),with peak force being attained earlier;prolonged knee extension,with a greater range of motion during the roller ski-stop phase(28°±40 vs.16°±3°,p=0.00014);and more pronounced hip and knee flexion during most of the forward leg swing.The mechanical work performed against friction during rolling was significantly less with DSRUN than with DSCONV(0.04±0.01 J/m/kg vs.0.10±0.02 J/m/kg,p<0.001).Conclusion:Our findings demonstrate that DSRUN is characterize by more rapid propulsion,earlier leg extension,and a greater range of motion of knee joint extension than DSCONV-Further investigations,preferably on snow,should reveal whether DSRUN results in higher acceleration and/or higher peak speed.

Outcome of repair of chronic tear of the pectoralis major using corkscrew suture anchors by box suture sliding technique

AIM To assess the functional and clinical results of repair of chronic tears of pectoralis major using corkscrew and sliding suture technique. METHODS In this retrospective study, we reviewed the results of pectoralis major repair in 11 chronic cases(> 6 wk) done between September 2011 and December 2014 at our institute. In all cases repair was done by same surgeon using corkscrew suture anchors and box suture sliding technique. At 6 mo, after surgery magnetic resonance imaging was done to see the integrity of the repair. Functional evaluation was done using Penn and ASES scores. Pre and postoperative Isokinetic strength was measured.RESULTS Average follow-up was 48.27 ± 21.0 mo. The Wilcoxon signed rank test was used to evaluate the outcome scores. The average ASES score increased from an average of 54.63 ± 13.0 preoperatively to 95.09 ± 2.60 after surgery at their last follow-up. The average Penn score also increased from 5.72 ± 0.78, 2.81 ± 1.32 and 45.81 ± 1.72 to 9.36 ± 0.80, 8.27 ± 0.90 and 59 ± 1.34 for pain, satisfaction and function respectively. Follow up magnetic resonance imaging(MRI)(at 6 mo) showed continuity and the bulk of pectoralis major muscle in all cases. Average isokinetic strength deficiency in horizontal adduction at 60° was 13.63% ± 6.93% and at 120° was 10.18% ± 4.93% and in flexion at 60° was 10.72% ± 5.08% and at 120° was 6.63% + 3.74%. Results showed that both ASES and Penn score improved significantly(2 tailed P value = 0.0036).CONCLUSION We could conclude from this series that pectoralis major repair even in chronic cases using 5.5 mm corkscrew anchors give excellent functional and cosmetic results. In chronic cases the repairable length of the tendon is not available and sliding suture technique allows for fixation of worn out tendomuscular junction to bone without letting cutting through the muscle.

Postural control quantification in minimally and moderately impaired persons with multiple sclerosis:The reliability of a posturographic test and its relationships with functional ability

Background:Postural control has been associated with the functional impairment in persons with multiple sclerosis(pwMS).However,there is a need for reliable methods to assess postural control in early stages of the disease,when subtle changes can be difficult to detect.The aims of this study were to assess the absolute and relative reliability of a standing and a sitting posturographic protocol in minimally(Expanded Disability Status Scale≤2)and moderately(2.5≤Expanded Disability Status Scale≤4)impaired pwMS,and to analyze relationships among postural control and functional mobility and gait performance.Methods:To assess postural control in an upright stance,14 minimally and 16 moderately impaired pwMS performed six 70 s trials in tandem stance,3 with their weaker leg behind(TSWL)and 3 with their stronger leg behind(TSSL).Additionally,participants completed five 70 s trials using an unstable sitting protocol(US)to assess trunk stability.The mean radial errors of TSWL,TSSL,and US trials were calculated as postural control indexes.Furthermore,participants performed the Timed Up and Go test(TUG)and the Timed 25-foot Walk test(T25FW)to measure their functional mobility and gait speed,respectively.Reliability was evaluated using the intraclass correlation coefficient(ICC3,1)and the standard error of measurement(SEM).Analyses of variances were carried out to assess between-group differences.Hedges’g index(dg)was used to estimate the effect size of differences.Pearson correlation analyses(r)were performed to examine the relationships among the postural control and the functional tests.Results:Posturographic tests showed a high reliability in both minimally(0.87≤ICC≤0.92;9.32%≤SEM≤11.76%)and moderately(0.80≤ICC≤0.92;10.33%≤SEM≤15.33%)impaired pwMS.Similarly,T25FW and TUG displayed a high consistency in minimally(0.89≤ICC≤0.94;3.43%≤SEM≤5.17%)and moderately(0.85≤ICC≤0.93;5.57%≤SEM≤6.56%)impaired individuals.Minimally impaired pwMS showed a better performance on the TUG,T25FW,and TSWL than moderately impaired individuals(p<0.05;dg≥0.8).The TSWL,TSSL,and US variables correlated with TUG scores(0.419≤r≤0.604;p<0.05),but TSWL also correlated with T25FW scores(r=0.53;p<0.01).Furthermore,US scores correlated with both tandem stance parameters(TSWL:r=0.54,p<0.01;TSSL:r=0.43,p<0.05).Conclusion:Tandem and sitting posturographic tests provide reliable measures of postural control in pwMS,even in individuals with a homogeneous disease profile.Gait speed,functional mobility,and weaker leg status seem decisive in assessing the degree of physical activity limitation in pwMS.Finally,although trunk stability does not seem to be so affected by the course of the disease,it remains relevant for postural control and functional capacity.

Recognition for Frontal Emergency Stops Dangerous Activity Using Nano IoT Sensor and Transfer Learning

Currently,it is difficult to extract the depth feature of the frontal emergency stops dangerous activity signal,which leads to a decline in the accuracy and efficiency of the frontal emergency stops the dangerous activ-ity.Therefore,a recognition for frontal emergency stops dangerous activity algorithm based on Nano Internet of Things Sensor(NIoTS)and transfer learning is proposed.First,the NIoTS is installed in the athlete’s leg muscles to collect activity signals.Second,the noise component in the activity signal is removed using the de-noising method based on mathematical morphology.Finally,the depth feature of the activity signal is extracted through the deep transfer learning model,and the Euclidean distance between the extracted feature and the depth feature of the frontal emergency stops dangerous activity signal is compared.If the European distance is small,it can be judged as the frontal emergency stops dangerous activity,and the frontal emergency stops dangerous activity recognition is realized.The results show that the average time delay of activity signal acquisition of the algorithm is low,the signal-to-noise ratio of the action signal is high,and the activity signal mean square error is low.The variance of the frontal emergency stops dangerous activity recognition does not exceed 0.5.The difference between the appearance time of the dangerous activity and the recognition time of the algorithm is 0.15 s,it can accurately and quickly recognize the frontal emergency stops the dangerous activity.

Effects of intermittent sprint and plyometric training on endurance running performance

Purpose:The purpose of this study was to compare the effects of intermittent sprint training and plyometric training on endurance running performance.Methods:Fourteen moderately trained male endurance runners were allocated into either the intermittent sprint training group(n = 7)or the plyometric training group(n = 7).The preliminary tests required subjects to perform a treadmill graded exercise test,a countermovement jump test for peak power measurement,and a 10-km time trial.Training included 12 sessions of either intermittent sprint or plyometric training carried out twice per week.On completion of the intervention,post-tests were conducted.Results:Both groups showed significant reduction in weekly training mileage from pre-intervention during the intervention period.There were significant improvements in the 10-km time trial performance and peak power.There was also significant improvement in relative peak power for both groups.The 10-km time trial performance and relative peak power showed a moderate inverse correlation.Conclusion:These findings showed that both intermittent sprint and plyometric training resulted in improved 10-km running performance despite reduction in training mileage.The improvement in running performance was accompanied by an improvement in peak power and showed an inverse relationship with relative peak power.

Reflections on Long-Term Development and Use of Automated Scoring Technology in a Sport (Modified Boxing) Context

Technology is being increasingly used to aid judging in sport, but its employment as the primary means of scoring is rare. We have developed and implemented a fully automated scoring system in the context of a modified, low-risk form of boxing. The system, which requires contestants to wear vests and gloves incorporating sensor fabrics, has been used in multiple settings over the past five years. During that period, it has undergone progressive iteration guided by action research methodology. Here, we summarise that iteration, reflect on present status and identify possible future directions. We have found that concept of automated scoring has wide appeal, and the wearable technology is almost universally considered comfortable. Nevertheless, some issues remain to be addressed. Use of the technology requires considerable prior and subsequent commitment of time. Apparently valid contacts occasionally fail to score. Causative factors include the configuration of electrical circuitry in the vests and deterioration of that circuitry with repeated vest use and washing. Also, false positive scores are sometimes generated by vest self-shorting and effects of sweat. Many contestants adopt unorthodox styles aimed at exploiting the characteristics of the automated scoring methodology, affecting the aesthetics of the modified sport. There is an expectation that technologically-based scoring should have much greater accuracy than human judging, and should be essentially fail-proof. Disillusionment can occur in?situations where this expectation is not met. We have identified potential?solutions to all the existing issues, with some now being actively explored. Continuation of the quest seems justified by popular dissatisfaction with subjective human judging of boxing and other sports, but we have come to realise that purely technological judging can introduce unforeseen complexities. Our observations could be relevant to various sports interested in the notion of technological judging.

Assessment of the Knowledge of the Adolescent Female Football Players Regarding the Carbohydrate and Its Importance

Carbohydrate, in the form of glucose, is the preferred fuel for working muscles particularly during high intensity activity. Some carbohydrate will be used up irrespective of the type of exercise performed. A study was conducted to assess the knowledge of adolescent female football players regarding carbohydrate and its importance. It was found that 70% subjects were aware of the term carbohydrate. The awareness of the subjects regarding the term carbohydrate and its association with the function of carbohydrate is highly significant （P 〈 0.001）. The awareness level of the subjects on carbohydrate sources, type of carbohydrate to be consumed before, after and during competition was not significant. A need for developing nutrition education tools and imparting nutrition education programs becomes pertinent to enable the players to choose appropriate diet to enhance their performance.

A Portable Device for Intermittent Oxygen Supplementation during High-Intensity Exercise

Introduction: Oxygen supplementation increases physical performance during strenuous work, as known for more than 100 years. There is no widespread use among athletes, which could be due to logistical challenges with gas supply when breathing over 200 L/min. We hypothesized that a positive effect could be reached with a moderate increase in alveolar PO2. If so, a technical solution here called “Oxelerator” could be constructed combining intermittent gas supply with oxygen concentrators running of electricity and a small bottle. Methods. This study describes the theoretical details regarding gas flow and consumption as well as a practical test of the Oxelerator when used during intense exercise by two athletes with high VO2 and work capacity. Results: The Oxelerator generates a peak gas flow of 32 L/min dosed intermittently in 400 - 700 ms boluses adjusted to the inspiratory phase of breathing, mixing oxygen with surrounding air. Theoretical calculations show that 1 liter tank suffice for 20 - 40 minutes of high intensity exercise and hyperoxic FEO2 while breathing above 200 L/min. The first subject ran on a treadmill at a VO2 of 4.64 L/min, RER 0.94. Then intermittent oxygen supplementation was initiated, and FEO2 reached 25.96% after 1 minute. The second subject rowed an ergometer at 330 W. VO2 stabilized at 5.67 L/min, with RER 0.91. After 1 minute of oxygen supplementation mixed expired FEO2 was 22.58% suggesting that inspired FO2 averaged 28 - 31%. Conclusions: A portable technical solution is proposed that enable intermittent O2 supplementation enough to increase end-expiratory FO2 during intense workloads. This will enable hyperoxic exercise for athletes.

Effects of exercise-based cardiac rehabilitation on inflammatory biomarkers in patients with cardiovascular disease:a systematic review with meta-analysis

Background:Evidence supports the anti-inflammatory effect of exercise-based cardiac rehabilitation(CR)in patients with cardiovascular disease(CVD).Nonetheless,the influence of training variables on the effects of exercise training is debateable.Therefore,this systematic review with meta-analysis aims to i)estimate the effects of exercise-based CR on the circulating levels of inflammatory biomarkers in patients with CVD based on the type of exercise,and ii)analyse the influence of other potential moderator variables.Methods:Electronic searches were performed in PubMed,Scopus,and Web of Science databases up to October 2022.A random-effects models of standardised mean difference(SMD)were used.Subgroup analyses and meta-regressions were used to carry out heterogeneity analyses.Results:Aerobic exercise diminished the levels of C-reactive protein compared with the control group in patients with CVD(SMD+=-0.33[95%CI=-0.47,-0.20),as well as the levels of tumor necrosis factor-alfa exclusively in patients with chronic heart failure(SMD+=-0.38[95%CI=-0.59,-0.17]).Moreover,heterogeneity analyses showed that the effect of aerobic exercise on vascular cell adhesion molecule-1 is higher in studies that carried out a CR programme based exclusively on exercise,as well as in studies that performed a shorter intervention period or carried out a lower number of exercise sessions(P≤0.05).Conclusion:Our findings support the anti-inflammatory effect of aerobic exercise in patients with CVD.The low number of studies testing interventions using resistance or combined exercise precludes a definitive answer about their anti-inflammatory effects in this patient population.

Cardiac Structure and Function in Men with Prostate Cancer Receiving Androgen-Deprivation Therapy and the Effects of Recreational Small-Sided Football Training:A Randomized Controlled Trial

Purpose: Androgen deprivation therapy (ADT) is a cornerstone in prostate cancer (PCa) management that prolongs PCa-free and overall survival, but effects of ADT on human cardiac function have not been investigated. We used echocardiography to examine cardiac structure and function in patients with prostate cancer receiving ADT and to determine whether an exercise intervention can elicit cardiac adaptations in these subjects. Methods: Forty-three patients with prostate cancer receiving ADT were randomized to 12 weeks football training (ST group;n = 20) or usual care (control [CO] group;n = 23). Cardiac function was assessed at baseline and after 12 weeks by comprehensive echocardiography. Peak oxygen consumption, blood pressure and peripheral microvascular function was also measured. Results: At baseline, no considerable echocardiographic abnormalities were observed. In the ST group, increases in left ventricular diastolic function variables including E/A ratio (P = 0.03), E’ (P = 0.016), E’TDIcolor (P = 0.040) and in left atrial diameter (P = 0.001) were observed after 12 weeks. In addition, diastolic blood pressure (P = 0.027) and resting heart rate (P 0.001) were reduced after ST. In the CO group, no significant changes were observed in the examined variables after 12 weeks. Despite within group changes in the ST group, no significant differences were observed after 12 weeks between groups in echocardiographic variables, peak oxygen consumption, blood pressure and peripheral microvascular function. Conclusion: In men with prostate cancer receiving ADT, echocardiography showed no abnormalities in cardiac structure and function. Twelve weeks of ST failed to elicit significant cardiovascular adaptations and ADT may blunt cardiovascular adaptations to short-term exercise training.

Buttress plate fixation of coronoid process fractures via a medial approach

Purpose:To assess the clinical and radiographic outcomes of coronoid process fractures surgically managed with buttress plate fixation via a medial approach.Methods:A retrospective review of all coronoid fractures surgically fixed in our institution using a buttress plate technique via a medial approach between June 2012 and April 2015 by the senior author was performed.These fractures were all sizeable fractures contributing to persistent elbow instability in terrible triad or varus posteromedial rotatory instability injury patterns.A prospective telephone questionnaire was conducted to assess patient outcomes using the disabilities of the arm,shoulder and hand(DASH)score and Mayo hlbow performance score(MEPS).Results:Twelve patients were included in the study,comprising 10 males and 2 females with an average age of 39 years(range,19-72 years).Mean follow-up was 16 months(range.4-18 months).The average time to radiographic union was 4 months(range.3-7 months).Range of motion measurements at final follow-up were obtained in 11 out of 12 patients,with one patient defaulting follow-up.All 11 patients displayed a functional elbow range of motion of at least 30°-130°.with an average arc of motion of 130°(range.110°-140°).mean elbow flexion of 134°(range.110°-140°)and mean flexion contracture of 3°(range.0°-20°).The mean DASH score was 16(range.2.5-43.8)and the mean MEPS was 75(range.65-100).Complications observed included one patient with a superfic ial wound infection which resolved with a course of oral antibiotics and one patient with radiographic evidence of heterotopic ossification which was conservatively managed.No residual elbow instability was observed and no reoperations were performed.Conclusion:Buttress plate fixation via a medial approach of coronoid process fractures that contribute to persistent elbow instability represents a reliable method of treatment that produces satisfactory and predictable outcomes.

Complications in the management of closed high-energy proximal tibial plateau fractures

Purpose： To report complications in the management of complex closed proximal tibial fractures. Method： A retrospective study was conducted to analyze the infectious and noninfectious complications encountered in the management of high-energy Schatzker type V and VI tibial plateau fractures. All patients were treated at the level 1 trauma centre between January 20tl and March 2014. Sixty two patients were included in the study. The mean patient age was （43.16 ±11.59） years with 60 males and 2 females. Infectious complications like superficial and deep infection, wound dehiscence, malalignment in the immediate postoperative period and in follow-up period were noted. Results： The overall complication rate was 30.65% （19 out of 62）. Infectious complications were noted in 20.97% cases （13162）. In majority of the cases （8113）, superficial infection was seen which managed with regular dressing and antibiotic administration. The patients （5/13） who had developed deep-seated infection were subjected to repeated debridements, flap coverage, implant removal or amputation depending upon the host response. Thirteen patients had experienced noninfectious complications. Hardware related complications were noticed in six patients and four among them received a secondary procedure. Malalignment was observed in seven patients but only single patient underwent subsequent operative intervention. Conclusion： Proximal tibial plateau fractures especially Shatzker type V and VI are associated with extensive soft tissue damage even in closed injuries. The complications encountered in the management of these fractures can be minimized with appropriate patient selection and minimal soft tissue dissection.