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.     

OCTA对青少年近视人群视网膜微血管密度的观察

目的：基于光学相干断层扫描血管成像（OCTA）技术探讨青少年儿童近视与视网膜表层微血管密度 及视网膜厚度的相关性。方法：横断面研究。共纳入2018年5─11月于四川大学华西医院眼科门 诊就诊的7～14岁青少年近视患者105例（193眼）。对所有受检者进行光学相干断层扫描（OCT）和 OCTA检查，量化分析黄斑中心凹视网膜厚度和各部位视网膜表层微血管密度。单因素方差分析比 较低、中、高度近视组各部位视网膜微血管密度及视网膜厚度的差异。采用Pearson相关系数探讨视 网膜厚度与各部位视网膜表层微血管密度的相关性。Spearman相关系数用于探讨等效球镜与中心凹、 旁中心凹视网膜表层微血管密度以及视网膜厚度的关系；分段多项式函数分析等效球镜度与外环及 直径6 mm完整视网膜表层微血管密度的关系。结果：旁中心凹、外环、直径6 mm完整区域视网膜 表层微血管密度在低、中、高度近视组间比较差异均具有统计学意义（F=11.651、14.499、14.232， 均P<0.001）。年龄与中心凹视网膜厚度之间有较弱正相关关系（r=0.187，P=0.011），与各部位微血管 密度均无相关性。等效球镜度与旁中心凹视网膜微血管密度有相关性（r=-0.301，P<0.001），与外环、 直径6 mm完整区域视网膜表层微血管密度呈曲线相关（r=-0.319，P<0.001；r=-0.307，P<0.001）。 但与中心凹视网膜表层微血管密度及视网膜厚度无显著相关性。此外，中心凹处视网膜厚度与微血 管密度呈正相关（r=0.691，P<0.001），与其余部位微血管密度无相关性。结论：青少年近视程度数 与旁中心凹、外环及直径6 mm完整区域视网膜表层微血管密度呈负相关；中心凹处视网膜厚度与年 龄、微血管密度呈正相关。     

Anatomically contoured large femoral heads can reduce iliopsoas impingement: A cadaver verification study

While use of large heads in total hip arthroplasty (THA) continues to grow, concerns have been raised regarding anterior hip pain resulting from impingement of the prosthetic head against soft-tissues like the iliopsoas. To address these concerns, a new anatomically contoured head (ACH) was developed. In this study cadaver tests were utilized to show that iliopsoas impingement/tenting caused by conventional heads is significantly relieved with the more rounded and reduced distal profile of the ACH. Thus, the ACH implant may be able to decrease the risk of soft-tissue impingement with conventional heads, particularly in the smaller hip.     

Anomalous Origin of the Left Coronary Artery from the Pulmonary Artery: Diagnoses and Surgical Results in 12 Pediatric Patients

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital condition. It responds well to early diagnosis and treatment, but otherwise the prognosis is poor. We present our case series of 12 patients (mean age, 2 ± 2.58 yr; age range, 2 mo–8 yr), emphasizing the diagnostic process and discussing our surgical results. The diagnosis of ALCAPA should be suspected in infants who have dilated cardiomyopathy with electrocardiographic changes that suggest ischemia, and in older children who have isolated mitral regurgitation. When clinical suspicion is high, the results of 2-dimensional echocardiography combined with color-flow Doppler studies in expert hands can establish the diagnosis, thus avoiding angiography in critically ill infants. The treatment of choice in our patients was transfer and reimplantation of the left coronary artery onto the ascending aorta. There were 2 deaths: both were infants in extremis who underwent emergency surgery. An older child with severe ventricular dysfunction was given mechanical ventricular assistance and then heart transplantation. As of this report, all 10 survivors remained well and asymptomatic.     

Utility of the 3‐Vessel and 3‐Vessel and Trachea Views in Prenatal Diagnosis of a Pulmonary Artery Sling

A pulmonary artery (PA) sling is a very rare congenital cardiovascular anomaly, and only a few studies have reported PA slings in fetuses. The relationship of the PA, aorta, ductus arteriosus, and trachea can be evaluated in the 3‐vessel and 3‐vessel and trachea views during fetal echocardiography. A PA sling can be detected by abnormal positioning of the left PA in relation to the trachea when sweeping from the 3‐vessel view cranially to the 3‐vessel and trachea view. Here we report 3 cases of fetal PA slings and their follow‐ups. Two cases were confirmed by postnatal echocardiography, and the other case was confirmed by a cardiovascular cast after pregnancy termination. We emphasize that the 3‐vessel and 3‐vessel and trachea views are of crucial importance in the prenatal diagnosis of a PA sling.     

髌周去神经化预防全膝关节置换术后膝前疼痛

目的　依据髌周解剖学特点，探讨全膝关节置换术（total knee arthroplasty，TKA）中应用髌周电灼去神经化的临床效果。 方法　纳入82名诊断为骨性关节炎的患者（91膝），予行双侧或单侧不置换髌骨的TKA，按随机对照原则将病人分为两组，共有41名实验组患者（45膝）在TKA中接受了髌周去神经化处理，41名对照组患者（46膝）未做该处理。手术主刀为同一骨科医师，均使用相同的膝关节假体系统。主要评价项目包括膝关节KSS评分、Western Ontario and McMaster Universities（WOMAC）、Feller髌骨评分及VAS评分。 结果　82名患者术后均获随访，平均随访时间为12个月，两组病人的膝关节KSS评分、WOMAC、Feller髌骨评分及VAS评分均无显著统计学差异（P>0.05）。 结论　在TKA中行髌周电灼去神经化，不能显著改善病人的预后。