Effects of anteriorly-loaded treadmill walking on dynamic gait stability in young adults

BackgroundAnteriorly-loaded walking is common in many occupations and may increase fall risk. Dynamic gait stability, defined by the Feasible Stability Region (FSR) theory, quantifies the kinematic relationship between the body’s center of mass (COM) and base of support (BOS). FSR-based dynamic gait stability has been used to evaluate the fall risk.Research questionHow does front load carriage affect dynamic gait stability, step length, and trunk angle among young adults during treadmill walking?MethodsIn this between-subject design study, 30 healthy young adults were evenly randomized into three load groups (0%, 10%, or 20% of body weight). Participants carried their assigned load while walking on a treadmill at a speed of 1.2 m/s. Body kinematics were collected during treadmill walking. Dynamic gait stability (the primary variable) was calculated for two gait events: touchdown and liftoff. Step length and trunk angle were measured as secondary variables. One-way analysis of variance was conducted to detect any group-related differences for all variables. Post-hoc analysis with Bonferroni correction was performed when main group differences were found.ResultsNo significant differences but medium to large effect sizes were found between groups for dynamic gait stability at touchdown (p = 0.194, η² = 0.114) and liftoff (p = 0.122, η² = 0.139). Trunk angle significantly increased (indicating backward lean) with the front load at touchdown (p < 0.001, η² = 0.648) and liftoff (p < 0.001, η² = 0.543). No significant between-group difference was found related to the step length (p = 0.344, η² = 0.076).SignificanceCarrying a front load during walking significantly alters the trunk orientation and may change the COM-BOS kinematic relationship and, therefore, fall risk. The findings could inform the design of future studies focusing on the impact of anterior load carriage on fall risk during different locomotion.     

轴向载荷分担比指导外固定器动力化的临床应用

目的:探讨轴向载荷分担比用于胫腓骨骨干骨折术后指导外固定器轴向动力化促进骨折愈合的有效性。方法:选取外固定器治疗的胫腓骨骨干骨折患者100例,随机分为观察组50例,对照组50例。观察组在轴向载荷分担比指导下行外固定器轴向动力化治疗,对照组未行动力化,随访比较两组的治疗效果。结果:所有患者均获随访,随访时间4～12个月,平均6.5个月,治疗期间所有患者均未出现外固定针断裂、松动及再骨折等并发症,观察组1例骨搬移患者轴向载荷分担比5%,X线片显示骨折断端有连续性骨痂通过,拆除外固定器连接杆后发生移位,恢复原数值行轴向加压再动力化,现已愈合。观察组除外1例骨搬移患者,其余49例患者外固定器固定时间为[(24.4±4.7)周],骨折临床愈合时间为[(22.4±4.7)周],与对照组50例患者外固定器固定时间[(29.3±5.6)周],骨折临床愈合时间[(27.3±5.6)周]比较,显著减少(P0.05)。结论:外固定器轴向载荷分担比指导胫腓骨骨干骨折外固定术后轴向动力化可以加速骨折愈合,但不适合骨搬移截骨端已硬化患者。     

Return to competitive gymnastics training in the UK following the first COVID-19 national lockdown

Following the outbreak of COVID-19 (coronavirus), the UK entered a national lockdown, and all sport was suspended. The study aimed to explore the process of returning to gymnastics training after several months away from the gym, with a particular interest towards training load and injury. Twenty-six, national programmed gymnasts from Men's artistic, Women's artistic and Trampoline gymnastics recorded training load and injury whilst returning to training. At the end of data collection, three coaches were interviewed to further explore the experiences and practices of returning to training. Home-based training during lockdown was seen as beneficial in maintaining a level of fitness. Coaches described a gradual increase in training to reduce the risk of injury, and this partly explains a non-significant association between training load and a substantial injury (p = 0.441). However, week-to-week changes in training load following periods of additional restrictions (additional lockdown, periods of isolation, or substantial restrictions) were not always gradual. There was a significant association between an injury in the preceding week (niggle or substantial injury to a different body part) and a substantial injury in the subsequent week (RR: 5.29, p = 0.011). Monitoring training was described to be a useful practice during the process of returning to training. Coaches believed that although the short-term development of their gymnasts was affected, the long-term development would not be impacted from COVID-19. It is anticipated that learnings from this study can be applied to future practices and situations, particularly when gymnasts are away from the gym for an extended period.     

抗PD-(L)1、抗CTLA-4免疫治疗标志物研究进展

免疫检查点抑制剂已经改变了包括肺癌、黑色素瘤等许多肿瘤的治疗情况，并且在一些难治性肿瘤中表现出持久的应答率，然而在部分接受治疗的患者中表现出无反应及严重免疫相关副作用。为了优化免疫疗法的使用，可能需要多种临床应答的预测性标志物。本研究回顾了几种潜在有效生物标志物的可用数据，通过免疫组化检测肿瘤细胞和免疫细胞中PD-L1的表达，提示其是一种临床疗效的良好预测标志物;且PD-L1表达阴性者经免疫治疗后仍可获益。PD-L1表达在肿瘤内是动态和异质性的:在原发性灶和转移灶之间或在穿刺标本和大体标本之间表达不一致。肿瘤突变负荷与新抗原的高比率可获得持久获益。外周血标志物也可作为潜在标志物，增加的绝对淋巴细胞计数（ALC）与疾病控制和生存显著相关。在这篇综述中，我们旨在讨论抗PD-（L）1与抗CTLA-4 免疫治疗相关标志物研究现状，为临床运用提供指导，以便能够准确筛选出从这些治疗中获益更多的患者。     

孕期抗病毒治疗结合标准阻断措施对乙型肝炎高病毒载量孕妇所生婴儿母婴传播阻断的影响

目的分析乙型肝炎(乙肝)病毒(Hepatitis B virus,HBV)高载量孕妇孕期HBV脱氧核糖核酸(HBV desoxyribonucleic acid,HBV-DNA)水平和HBVe抗原(HBV e antigen,HBeAg)阳性率以及孕期抗病毒治疗结合标准阻断措施对其所生婴儿母婴传播阻断失败率的影响。方法通过医院信息系统收集HBV-DNA高载量(≥2×10^6IU/mL)孕妇血清学检测结果、抗病毒药物使用等信息,描述HBV-DNA载量和HBeAg阳性率;对HBV-DNA高载量孕妇所生婴儿进行乙肝疫苗(Hepatitis B vaccine,HepB)和乙肝免疫球蛋白(Hepatitis B immunoglobulin,HBIG)联合免疫,在完成第3剂HepB后7月龄-2岁对乙肝表面抗原和HBV-DNA进行随访检测,分析母婴传播阻断失败率。结果共纳入1822名HBV-DNA高载量孕妇,接受、未接受抗病毒治疗分别占75.19%、24.81%。孕妇妊娠期、分娩前HBV-DNA≥1.0×10^8IU/mL比例分别为68.10%(933/1370)、0.15%(2/1370)(χ^2=2692.27,P<0.0001)。接受抗病毒治疗组妊娠期、分娩前HBeAg阳性率分别为96.53%(1001/1037)、96.16%(1251/1301)(χ^2=0.23,P=0.635),未接受抗病毒治疗组妊娠期、分娩前HBeAg阳性率分别为97.70%(298/305)、96.98%(417/430)(χ^2=0.36,P=0.550)。两组HepB和HBIG联合免疫后母婴传播阻断失败率分别为0.42%(3/714)、6.67%(14/210)(χ^2=31.69,P<0.0001)。结论孕妇HBV-DNA高载量以≥1.0×10^8IU/mL为主,孕期抗病毒治疗可显著降低孕妇HBV-DNA载量,结合HepB和HBIG联合免疫可显著降低其所生婴儿HBV母婴传播阻断失败率。