Cognitive load imposed by ultrasound‐facilitated teaching does not adversely affect gross anatomy learning outcomes          下载免费PDF全文

Heather A. Jamniczky  Darrel Cotton  Michael Paget  Qahir Ramji  Ryan Lenz  Kevin McLaughlin  Sylvain Coderre  Irene W.Y. Ma 《Anatomical sciences education》2017,10(2):144-151

Ultrasonography is increasingly used in medical education, but its impact on learning outcomes is unclear. Adding ultrasound may facilitate learning, but may also potentially overwhelm novice learners. Based upon the framework of cognitive load theory, this study seeks to evaluate the relationship between cognitive load associated with using ultrasound and learning outcomes. The use of ultrasound was hypothesized to facilitate learning in anatomy for 161 novice first‐year medical students. Using linear regression analyses, the relationship between reported cognitive load on using ultrasound and learning outcomes as measured by anatomy laboratory examination scores four weeks after ultrasound‐guided anatomy training was evaluated in consenting students. Second anatomy examination scores of students who were taught anatomy with ultrasound were compared with historical controls (those not taught with ultrasound). Ultrasound's perceived utility for learning was measured on a five‐point scale. Cognitive load on using ultrasound was measured on a nine‐point scale. Primary outcome was the laboratory examination score (60 questions). Learners found ultrasound useful for learning. Weighted factor score on “image interpretation” was negatively, but insignificantly, associated with examination scores [F (1,135) = 0.28, beta = ?0.22; P = 0.61]. Weighted factor score on “basic knobology” was positively and insignificantly associated with scores; [F (1,138) = 0.27, beta = 0.42; P = 0.60]. Cohorts exposed to ultrasound had significantly higher scores than historical controls (82.4% ± SD 8.6% vs. 78.8% ± 8.5%, Cohen's d = 0.41, P < 0.001). Using ultrasound to teach anatomy does not negatively impact learning and may improve learning outcomes. Anat Sci Educ 10: 144–151. © 2016 American Association of Anatomists.  相似文献   

Changes in ankle joint stiffness due to stretching: The role of tendon elongation of the gastrocnemius muscle     

《European Journal of Sport Science》2013,13(2):111-119

Abstract

The purpose of this study was to investigate changes in ankle joint stiffness and the associated changes in the gastrocnemius muscle and tendon due to static stretching. Seven healthy male participants lay supine with the hip and knee joints fully extended. The right ankle joint was rotated into dorsiflexion from a 30° plantar flexed position and the torque measured by a dynamometer. The ankle joint was maintained in a dorsiflexed position for 20 min (static stretching of the calf muscles). We performed surface electromyography of the medial and lateral gastrocnemii, the soleus, and the tibialis anterior of the right leg to confirm no muscle activity throughout static stretching and the passive test (passive dorsiflexion). During static stretching, the ankle joint angle and elongation of the gastrocnemius were recorded by goniometry and ultrasonography, respectively. Tendon elongation of the gastrocnemius was calculated based on the changes in the ankle joint angle and muscle elongation. In addition, the relationships between passive torques and ankle joint angles, and elongation of muscle and tendon, were examined before and after static stretching. The ankle dorsiflexion angle and tendon elongation increased significantly by 10 min after the onset of static stretching, while there was no further increase in muscle length. In addition, ankle dorsiflexion angle and tendon elongation at an identical passive torque (30 N · m) increased significantly (from 24±7° to 33±5° and from 17±2 mm to 22±1 mm, respectively) after static stretching. However, muscle elongation was unchanged. In conclusion, the current results suggest that an increase in the ankle joint dorsiflexion angle due to static stretching is attributable to a change in tendon not muscle stiffness.  相似文献   

The time course of muscle-tendon properties and function responses of a five-minute static stretching exercise     

《European Journal of Sport Science》2013,13(9):1195-1203

Abstract

The purpose of this study was to investigate the time course of the changes of muscle-tendon mechanical properties and the function responses of the plantar flexor muscles following 5?×?60?s of static stretching.

Fourteen healthy volunteers were tested on four separate days in a random order with three different rest times (0, 5, 10?min) after 5?×?60?s of stretching or following a control period without stretching. During each test, the dorsiflexion range of motion (RoM), passive resistive torque (PRT), and maximum voluntary contraction (MVC) were measured with a dynamometer. Ultrasonography of the gastrocnemius medialis (GM) muscle-tendon junction displacement and motion capture allowed us to determine the length changes in the tendon and muscle, respectively, and hence to calculate their stiffness.

We observed an increase in RoM and decrease in MVC at 0, 5, and 10?min post-stretching. This could be attributed to an increase in muscle elongation which lasted at least 10?min. A decrease in muscle-tendon stiffness was observed immediately, but not 5 or 10?min after the stretching. A decrease in PRT and muscle stiffness was observed up to 5?min after the stretching. No changes were detected in tendon stiffness or in any variable in the control group.

The effects of a 5?×?60?s static stretching exercise changes the muscle-tendon functions (RoM, MVC), which are related to mechanical changes of the muscle but not the tendon structure, respectively. Although the functional changes last for at least 10?min, changes in muscle stiffness were only observed up to 5?min after the stretching exercise.  相似文献   

优秀高山滑雪运动员体质、身体形态学及跟骨超声骨量的研究     

魏亚茹  赵文艳  张莹 《冰雪运动》2013,(1):38-42

在运动训练中,优秀高山滑雪运动员保持较好的体质、身体形态学、跟骨超声骨量对提高高山滑雪项目运动员的运动成绩是非常有好处的。采用文献资料法、测试法、数理统计法对优秀高山滑雪运动员体质、身体形态学与跟骨超声骨量现状进行研究,为其科学运动训练提供借鉴。结果显示：高山滑雪运动员体重、身体质量指数、体脂率、瘦体重显著低于对照组,身高与对照组差异不显著;高山滑雪女子运动员体脂率显著低于对照组,瘦体重显著高于对照组,其他各项指标与对照组差异不显著;运动员体质方面男子高山滑雪运动员握力体重指数显著低于体育大学生,其他各项指标显著高于对照组,女子高山滑雪运动员体质各项指数显著高于对照组;高山滑雪运动员跟骨超声骨量参数均显著高于对照组。  相似文献   

Biceps femoris long head muscle fascicle length does not differ between sexes     

Fearghal P. Behan  Rachael Moody  Tejal Sarika Patel  Edward Lattimore  Thomas M. Maden-Wilkinson  Thomas G. Balshaw 《Journal of sports sciences》2013,31(21):2452-2458

ABSTRACT

Hamstring strain injury (HSI) rates are higher for males vs. females. This cross-sectional study investigated if inherent differences in biceps femoris long head (BF_LH) fascicle length (Lf) exist between recreationally active males and females (i.e., individuals without specific training practice history). Twenty-four young healthy participants (12 males; 12 females) had their BF_LH muscle architecture (Lf, pennation angle [θp], and muscle thickness [MT]) measured using B-mode ultrasonography. Eccentric and isometric knee flexion strength were also assessed. BF_LH Lf did not differ between sexes when expressed in absolute terms (males, 81.5 ± 14.7 mm; females, 73.6 ± 15.9 mm, P = 0.220, effect size (ES) = 0.52) or relative to femur length (0.140 ≤ P ≤ 0.220, ES = 0.63). Similarly, BF_LH θp did not differ between sexes (P = 0.650) but BF_LH MT was 18.9% larger for males vs. females (P = 0.024, ES = 0.99). Isometric and eccentric knee flexion strength was greater for males vs. females in absolute terms ([both] P < 0.001, 2.00 ≤ ES ≤ 2.27) and relative to body mass ([both] P < 0.001, 1.93 ≤ ES ≤ 2.13). In conclusion, factors other than BF_LH Lf seem likely to be implicated in higher male vs. female HSI rates.  相似文献   

酵母紫外线诱变后培养温度与酒精发酵性状变异相关性研究     

戴朝波  吴雪昌  严力蛟 《科技通报》2008,24(3):325-329

酿酒酵母(Saccharomyces cerevisiae)Hs27α菌株经UV诱变后,分别置于31℃、40℃等不同的温度下培养,结果表明:在胁迫温度40℃下培养,子代菌株中正突变菌株(指产酒量高于对照的菌株)的平均产酒能力明显高于31℃下培养的菌株。31℃下培养的正突变菌株的平均产酒量提高4.89%,而在40℃下培养的则为8.75%。用15种随机引物对出发菌株与UV诱变子代菌株进行总DNA的RAPD测验证明,在接近抑制生长的胁迫温度(本文为40℃)下培养获得的子代中,DNA水平的变异程度比在31℃的要高得多。这一方法较大幅度提高了酵母紫外诱变选育高产菌种的效率,也为酿酒酵母UV诱变机制的进一步研究提供了新途径。  相似文献   

The influence of biological sex and cuff width on muscle swelling,echo intensity,and the fatigue response to blood flow restricted exercise     

Vickie Wong  Takashi Abe  Raksha N. Chatakondi  Zachary W. Bell  Robert W. Spitz  Scott J. Dankel 《Journal of sports sciences》2019,37(16):1865-1873

The purpose was to determine if the muscle swelling, echo intensity, and fatigue responses to blood flow restriction differs based on cuff width (Experiment 1), applied pressure (Experiment 2), and sex. Ultrasound of muscle was taken before and after exercise. In Experiment 1 (n = 96), men swelled more than women and more with a narrow cuff than a wide cuff (0.60 cm vs. 0.52 cm). Expressed as a percentage change, there were no longer differences between cuffs (Narrow: 15% vs. Wide: 14%) or sex (Men: 14% vs. Women: 15%). Echo intensity remained unchanged. Women required more repetitions to reach task failure in sets 2, 3, and 4. In Experiment 2 (n = 87), men swelled more than women (Men: 0.46 cm vs. Women: 0.31 cm). Expressed as a percentage change, there were no differences. Echo intensity decreased in both conditions and to a greater extent with a higher applied pressure. If the acute muscle swelling response is important for initiating long term adaptation, then our results indicate that neither cuff width, sex, nor applied pressure will differentially impact the adaptation observed via this mechanism. Changes in echo intensity were inconsistent and the utility of this measurement may need to be reconsidered.  相似文献   

定量超声骨质测量对健骨运动与钙剂补充效果的评定   总被引：6，自引：0，他引：6  

张林  张庆燕 《体育与科学》1999,20(3):6-10,5

本研究应用定量超声技术,在清华大学对健骨运动和钙剂补充效果进行了比较 研究。研究结果显示：科学的健骨运动使绝经后女性跟骨ＢＵＡ和Ｒ）Ｓ水平升高,骨 质疏松发生率降低;运动并配合钙剂补充的上述效应大于单纯位骨运动。表明合理的 营养补充和科学的健骨运动是提高骨质量的有效措施。  相似文献   

微波合成笨氧乙酸     

Wu Xiaowei  Yan XiaoQinEd.Dept. Of Chemistry Chenzhou Teachers College Hunan China 《湘南学院学报》1998,(1)

在水溶剂中,使用微波合成苯氧乙酸,反应仅需2-4分钟,收率达84.2％。  相似文献   

氢气和氯气爆鸣演示实验的研究     

闵凡新  付立海  董艳辉  杜相微 《通化师范学院学报》2002,23(5):74-77

本实验将氢氯混合气体分别在日光、镁条、照相机闪光灯的照射下进行反应，探索氢氯爆鸣的最佳实验条件。  相似文献