Sensory regulation and mechanical effects of sustained high intensity stretching of the anterior compartment of the thigh

BackgroundBallet dancers, contortionists, gymnasts, or other sportspeople spend long hours performing stretches while training. Although most studies on stretching consider fascia lengthening to be difficult, athletes manage to lengthen their fascia.AimTo assess the relationship between lengthening fascial structures of the anterior compartment of the thigh and the self-reported sensation of discomfort and pain during a sustained and repeated high intensity stretch.MethodsOur analysis was based on the data of 7 high school male elite rugby players who completed 11 sessions of stretching (10-min quasi-static stretch of the rectus femoris and fascia lata, at the maximum intensity tolerated), performed twice per week. The measured outcomes included hip range of motion, the length of the structures of the anterior compartment, subjective pain and tension during the stretch, and the level of surface electromyography activity. Values were compared before and after completion of the 11 sessions.ResultsMyofascial length increased by 1 cm. The necessary force applied increased from 124 to 164 N. However, the maximal tolerated stretching intensity did not change significantly (from 205 to 206 N). The increase in length was principally contributed by the rate of fascial creep upon force application, and not by contractile tissue. Subjective levels of tension were related to the stretching force applied and pain was related to the lengthening.ConclusionSensations can be used to adjust the intensity and duration of stretching. Soft matter physics provides a new interpretation of fascia lengthening and strengthening during a high intensity stretch.     

Effect of self-myofascial release on myofascial pain,muscle flexibility,and strength: A narrative review

Background

Numerous techniques have been employed to treat myofascial pain syndrome. Self-myofascial release (SMFR) is a relatively new technique of soft tissue mobilization. The simplicity and portability of the SMFR tools allow it to be easily implemented in any type of fitness or rehabilitation program. It is an active method and can be used by anyone at home or at the workplace.

A comparison of two muscle energy techniques for increasing flexibility of the hamstring muscle group

Variations in the application of muscle energy technique (MET) for increasing the extensibility of muscles have been advocated, but little evidence exists to support the relative merit of a particular approach. This study investigated two types of muscle energy techniques that have been advocated in the osteopathic literature that differ primarily in the duration of the post-contraction stretch phase. Forty asymptomatic participants (mean age=22.1±3.5, male female=1:4) were randomly allocated to one of two groups (Group 1: MET with 30-s post-isometric stretch phase; Group 2: MET with 3-s post-isometric stretch phase). Hamstring length was measured using active knee extension (AKE). Participants received an initial application of the allocated intervention, and then a second application 1 week later. Analysis with a split-plot ANOVA revealed a significant effect of time (F_3,36=42.30;p<0.01), but no significant time*group interaction (F_3,36=0.12; p=0.95). Post-hoc analysis revealed that the significant differences over time occurred between pre- and post-measurements at both weeks, and between post-Week 1 and pre-Week 2 measurements.Both techniques appeared to be equally effective in increasing hamstring extensibility, and there appeared to be sustained improvement 1 week following the initial treatment. The findings suggest that altering the duration of the passive stretch component does not have a significant impact on the efficacy of MET for short-term increases in muscle extensibility.     

基于Surface Evolver模拟液桥断裂距离

目的研究面间液桥断裂距离随着液桥体积、球面半径和固-液接触角的变化规律。方法利用SurfaceEvolver程序模拟介于球形表面和平面间一定体积液桥的拉伸、断裂的演变过程,从模拟结果中得到给定液桥体积、球面半径以及固体表面润湿性质这些参数下的液桥的断裂距离。结果以Lian等和Willett等所给出公式为基础得到液桥断裂距离关于参数液体体积、球面半径和接触角的理论公式,模拟结果与理论预测结果比较,发现当固体表面为亲水性质时,模拟结果与理论结果整体上吻合很好(偏差<4.3%);当固体表面为疏水性质时,模拟结果随着疏水性质的增加与理论估计的偏差会增大。结论 Surface Evolver可以很好地模拟液桥准静态拉伸和断裂过程,从而得到液桥断裂距离。Lian等和Willett等所给出的理论公式是由亲水表面数据拟合出来的,这也是在疏水性质表面上本文所给液桥断裂距离的理论公式预测结果与模拟结果偏差增大的原因。     

牵张应力对退变椎间盘髓核细胞增殖凋亡及细胞外基质表达的影响

目的 探讨不同强度牵张应力刺激对体外培养的人退变髓核细胞增殖凋亡和细胞外基质表达的影响。 方法 分选并体外培养人退变的髓核细胞,使用四点弯曲细胞力学装置对细胞施加不同强度的牵张应力,根据施加牵张应力强度的不同分为对照组（未给予应力刺激）、低强度组（1000 μ）、中强度组（2000 μ）和高强度组（4000 μ）四组。采用流式细胞仪测定退变髓核细胞的增殖情况;采用实时荧光定量聚合酶链反应（qPCR）检测各组细胞的细胞增殖核抗原(PCNA)、细胞凋亡相关蛋白B淋巴细胞瘤-2基因（Bcl-2）与Bcl-2相关X蛋白（Bax）、以及Ⅱ型胶原（ColⅡ）和蛋白聚糖(Aggrecan)的基因表达情况并进行分析。 结果 在不同强度的牵张应力作用下,退变髓核细胞的增殖凋亡和细胞外基质分泌呈现不同的变化。随着施加力学强度的增加,髓核细胞的增殖指数和PCNA基因表达水平先升高而后又逐渐降低,差异有统计学意义（P<0.05）。髓核细胞凋亡相关基因Bcl-2/Bax mRNA值在1000 μ强度牵张应力作用下为对照组的1.53倍,而在2000 μ和4000 μ强度下分别为0.71和0.43,同样呈现出随应力刺激增加先升高又降低的趋势,差异均有统计学意义（P<0.05）。给予1000 μ强度应力刺激后,Col Ⅱ和Aggrecan均有不同程度的表达增加,分别增加了2.1倍和2.3倍,与对照组比较,差异有统计学意义（P<0.05）。随着牵张应力强度的增加,Col Ⅱ和Aggrecan基因表达逐渐降低,在4000 μ强度牵张应力刺激时,二者基因表达最低,差异具有统计学意义（P<0.05）。 结论 不同强度的牵张应力对人退变髓核细胞的增殖凋亡以及细胞外基质的表达作用不同。     

A review on static splinting therapy to prevent burn scar contracture: Do clinical and experimental data warrant its clinical application?

Background

Static splinting therapy is widely considered an essential part in burn rehabilitation to prevent scar contractures in the early phase of wound healing. However, scar contractures are still a common complication. In this article we review the information concerning the incidence of scar contracture, the effectiveness of static splinting therapy in preventing scar contractures, and specifically focus on the – possible – working mechanism of static-splinting, i.e. mechanical load, at the cellular and molecular level of the healing burn wound.

Method

A literature search was done including Pubmed, Cochrane library, CINAHL and PEDRO.

Results

Incidence of scar contracture in patients with burns varied from 5% to 40%. No strong evidence for the effectiveness of static splinting therapy in preventing scar contracture was found, whereas in vitro and animal studies demonstrated that mechanical tension will stimulate the myofibroblast activity, resulting in the synthesis of new extracellular matrix and the maintenance of their contractile activity.

Conclusion

The effect of mechanical tension on the wound healing process suggests that static splinting therapy may counteract its own purpose. This review stresses the need for randomised controlled clinical trials to establish if static splinting to prevent contractures is a well-considered intervention or just wishful thinking.     

延伸医疗服务模式的探索

延伸医疗服务是一种新型的管理模式,是拓展医疗服务宽度和延伸患者生活质量的重要手段。延伸服务进一步加强医患沟通,增加患者对医护人员的信任、缓解紧张的医患关系,是医院走向社会的有效服务方式。本文结合当前医疗延伸服务的现状,探讨建立延伸医疗服务的措施。     

Effects of stretching exercise training and ergonomic modifications on musculoskeletal discomforts of office workers: a randomized controlled trial

Objective

To evaluate the effectiveness of exercise, ergonomic modification, and a combination of training exercise and ergonomic modification on the scores of pain in office workers with neck, shoulders, and lower back pain.