不同跑步着地习惯对跟腱形态学及其负荷特征的影响

目的 探究不同着地模式对跟腱形态学和负荷特征的影响。方法 招募习惯后跟着地跑者和习惯前掌着地跑者各14人,利用超声医学影像仪采集受试者的跟腱形态学特征（跟腱长度、横截面积、厚度）;利用三维测力跑台采集并计算受试者穿着缓冲跑鞋以10 km/h速度跑步时的跟腱负荷特征（跖屈力矩、跟腱力、负载率、冲量、应力等）。结果 与习惯后跟着地跑者相比,习惯前掌着地跑者踝关节跖屈力矩峰值、跟腱力峰值、平均负载率、峰值负载率均显著增加（P＜0.05）,但两组跑者跟腱长度、跟腱横截面积和跟腱厚度差异无统计学意义（P＞0.05）。结论 长期的前掌着地模式可以适应性地提高跟腱在重复性的“拉长-收缩”循环刺激中的力学特性。深入理解跟腱在不同着地方式下的响应,对于跑步爱好者以及运动医学领域中预防跟腱相关损伤具有重要的临床意义。     

即刻改变触地方式对着鞋跑时内侧纵弓在体运动学的影响

目的 探究即刻转换触地方式对着鞋跑步时内侧纵弓在体运动学的影响。 方法 采用高速双平面荧光透视成像系统采集 15 名健康男性跑者即刻改变触地方式前后右足在跑步支撑阶段[跑速:(3±0. 15) m/ s]的荧光图像。根据 CT 图像重建第 1 跖骨和跟骨三维骨骼模型及其局部坐标系,并通过 3D-2D 配准获取内侧纵弓在跑步支撑期的 6 自由度(six degree of freedom,6 DOF) 数据(简化为第 1 跖骨相对跟骨的运动)。 采用一维统计参数映射(statistical parametric mapping,SPM)比较即刻改变触地方式前后内侧纵弓的 6 DOF 运动趋势,并对其特征值进行配对样本 t 检验。 结果 相比后跟跑,即刻前掌跑时,在支撑期的 15% ~ 21% 第 1 跖骨相对跟骨的外移、支撑期 17% ~45% 第 1 跖骨的前移和支撑期的 18% ~ 39% 第 1 跖骨的背屈均显著增加(P<0. 05)。 即刻前掌跑时,第 1 跖骨相对跟骨的前移最大值、背屈最大值、前后平移活动范围及内侧纵弓压缩变化量均显著增加(P<0. 05)。 结论 由习惯后跟跑即刻转换为前掌跑后,内侧纵弓矢状面的形变显著增加,尤其是内侧纵弓的压缩变化量增加约 10% ,可能有助于其弹性能量的储存与释放。     

Ultrastructural Determinants of Murine Achilles Tendon Strength During Healing

The mechanisms by which tendon strength is established during growth and development and restored following injury are not completely understood and are likely to be complex, multifactorial processes. Several studies examining the relationship between mechanical behavior and ultrastructural characteristics of tendons and ligaments during growth and maturation suggest that collagen fibril diameter is strongly correlated with tendon strength. Because of the similarities between development and repair processes of musculoskeletal tissues, increases in tendon strength during healing may be related to increases in fibril ultrastructural parameters such as fibril size, numerical density, and area fraction. In this study, we compared murine Achilles tendons at various time points after tenotomy with sham-operated controls in tensile tests to failure and examined tendons using electron microscopy to assess collagen fibril ultrastructure. We found that in the 6-week period following Achilles tenotomy, fibril mean diameter remained significantly smaller than sham-side diameter by a factor of 2–3. Despite the persistently small fibril size, increasing numerical density resulted in a gradual increase in fibril area fraction. Biomechanical strength did not reach that of intact tendons until some time between 5 and 7 weeks, approximately the same time period when fibril area fraction began to approach sham values. These data suggest that parameters other than collagen fibril size are most responsible for increased tendon strength during healing.     

Effect of Calendula Officinalis Cream on Achilles Tendon Healing

In recent years, the scientific community has undertaken research on plant extracts, searching for compounds with pharmacological activities that can be used in diverse fields of medicine. Calendula officinalis L. is known to have antioxidant, anti‐inflammatory, antibacterial, and wound healing properties when used to treat skin burns. Therefore, the purpose of this study was to analyze the effects of C. officinalis on the initial phase of Achilles tendon healing. Wistar rats were separated in three groups: Calendula (Cal)—rats with a transected tendon were treated with topical applications of C. officinalis cream and then euthanized 7 days after injury; Control (C)—rats were treated with only vehicle after transection; and Normal (N)—rats without tenotomy. Higher concentrations of hydroxyproline (an indicator of total collagen) and non‐collagenous proteins were observed in the Cal group in relation to the C group. Zymography showed no difference in the amount of the isoforms of metalloproteinase‐2 and of metalloproteinase‐9, between C and Cal groups. Polarization microscopy images analysis showed that the Cal group presented a slightly higher birefringence compared with the C group. In sections of tendons stained with toluidine blue, the transected groups presented higher metachromasy as compared with the N group. Immunocytochemistry analysis for chondroitin‐6‐sulfate showed no difference between the C and Cal groups. In conclusion, the topical application of C. officinalis after tendon transection increases the concentrations of collagen and non‐collagenous proteins, as well as the collagen organization in the initial phase of healing. Anat Rec, 298:428–435, 2015. © 2014 Wiley Periodicals, Inc.     

不同鞋条件对后跟着地跑者跟腱负荷特征的影响

目的 探究不同鞋条件（极简鞋和传统跑鞋）对跑步时跟腱负荷特征的影响。方法 招募16名健康男性后跟着地跑步爱好者,要求其以3.16~3.50 m/s速度在两种鞋条件下完成跑步实验。采用超声影像仪获取跟腱横截面积成像。采用运动捕捉系统和三维测力台获取踝关节矢状面运动学和地面反作用力数据,并计算踝关节和跟腱的力学参数。采用配对样本t检验比较两种鞋条件对各因变参数（踝关节角度、触地角度、跟腱力、应力、应变等）的影响。结果 与传统跑鞋相比,穿着极简鞋时的足触地角度显著降低39.9%。同时,踝关节力矩、跟腱力峰值、跟腱负载率峰值和平均负载率均显著增加,而达到跟腱力峰值的时间显著减小。穿着极简鞋时的跟腱应力峰值、跟腱应变峰值及其应力率和应变率峰值也显著增加。结论 习惯穿着传统跑鞋并采用后跟着地的跑者在穿着极简鞋后显著增加了跟腱的负荷特征,建议该类跑者循序渐进地过渡至极简鞋,以适应性地提高跟腱承受负荷的能力。     

体内移植羊膜对家兔肌腱损伤模型肌腱愈合的影响

研究的目的在于观察羊膜体内移植对肌腱损伤修复的影响。60 只跟腱损伤家兔动物模型采用同体对照动物实验方法,大体观察伤口愈合、肌腱粘连及肌腱肥大情况,并分别于术后第 2、4、6 周等3个时间点取跟腱,HE染色观察损伤区域炎细胞浸润和成纤维细胞数量,免疫组化染色观察胶原纤维排列塑形状况,拉伸试验测定肌腱弹性模量。另取 4 只家兔不做肌腱切断术作为正常对照,在第 0周 测定肌腱弹性模量。全部实验动物皮肤切口在术后 1 周 内基本愈合,未发生伤口感染情况。羊膜实验组跟腱粘连动物数量和肌腱断裂区域肥大程度低于阴性对照组(P<0.05)。术后第 2 周,两组动物炎症反应均达到最高值,但羊膜实验组炎细胞（包括中性粒细胞和单核细胞）浸润数量低于阴性对照组(P<0.05)。两组实验动物样本中成纤维细胞数量和胶原纤维积累数量无明显差异（P >0.05）,但羊膜实验组成纤维细胞和胶原纤维排列更具有序性,尤其是在术后第 6 周,明显好于阴性对照组。术后第 2 周和第4 周,羊膜实验组肌腱弹性模量均优于阴性对照组(P <0.05)。羊膜具有促进肌腱早期愈合和抗炎、抗粘连作用。     

The Effect of the Achilles Tendon on Trabecular Structure in the Primate Calcaneus

Humans possess the longest Achilles tendon relative to total muscle length of any primate, an anatomy that is beneficial for bipedal locomotion. Reconstructing the evolutionary history of the Achilles tendon has been challenging, in part because soft tissue does not fossilize. The only skeletal evidence for Achilles tendon anatomy in extinct taxa is the insertion site on the calcaneal tuber, which is rarely preserved in the fossil record and, when present, is equivocal for reconstructing tendon morphology. In this study, we used high‐resolution three‐dimensional microcomputed tomography (micro‐CT) to quantify the microstructure of the trabecular bone underlying the Achilles tendon insertion site in baboons, gibbons, chimpanzees, and humans to test the hypothesis that trabecular orientation differs among primates with different tendon morphologies. Surprisingly, despite their very different Achilles tendon lengths, we were unable to find differences between the trabecular properties of chimpanzee and human calcanei in this specific region. There were regional differences within the calcaneus in the degree of anisotropy (DA) in both chimpanzees and humans, though the patterns were similar between the two species (higher DA inferiorly in the calcaneal tuber). Our results suggest that while trabecular bone within the calcaneus varies, it does not respond to the variation of Achilles tendon morphology across taxa in the way we hypothesized. These results imply that internal bone architecture may not be informative for reconstructing Achilles tendon anatomy in early hominins. Anat Rec, 296:1509–1517, 2013. © 2013 Wiley Periodicals, Inc.     

Changes of Achilles Tendon Reflex Amplitudes During a Fixed Foreperiod of Four Seconds

Preparation for a voluntary foot or finger response was studied by evoking Achilles tendon (T) reflexes. Reflexes were evoked simultaneously in both legs at 13 points between 100 and 4300 msec after the warning signal. With this paradigm, the time course of changes in reflex amplitudes related to preparatory processes could be measured simultaneously in the leg involved in the response and in the uninvolved leg. Immediately following the warning stimulus, the reflex amplitudes increased in both involved and non-involved muscles, presumably reflecting a general non-specific arousal. During the second half of the foreperiod, reflex amplitudes in non-involved muscles remained elevated, perhaps reflecting a general activation of the motor system, but returned to baseline in the involved muscles. It is hypothesized that the consistently smaller reflex amplitudes in the involved leg during the entire ISI reflect a presynaptic inhibition of the la afferents to the motoneurons involved in the response. Following the response stimulus, reflex amplitudes increased in both involved and non-involved muscles, although in the former at an earlier point and to a greater extent. It is suggested that this increase following the response stimulus is a manifestation of the transition from motor preparation to response execution.     

跑步时足偏角对胫骨冲击影响的探索性研究

目的探究跑步时足偏角对胫骨冲击的影响。方法 15名健康成年受试者分别以惯用、内八、外八的步态跑步,比较跑步者在不同足偏角跑步时的胫骨冲击(通过冲击峰值、平均加载率、最大加载率和最大胫骨加速度表征),探究跑步时足偏角对胫骨冲击是否有影响。并且比较跑步者不同步态下的躯干前倾角、着地方式、步频和步宽的变化,探究影响可能的原因。结果与惯用步态相比,内八和外八步态的最大胫骨加速度分别显著增加19.3%和24.5%,冲击峰值均显著增加7.6%,平均加载率分别显著增加7.9%和9.5%,最大加载率分别显著增加3.9%和10.9%。没有观测到躯干前倾角、着地方式、步频和步宽的显著性变化。结论足偏角有可能是除躯干前倾角、着地方式、步频和步宽外的另一种影响胫骨冲击的步态运动学参数,对其进行进一步研究将对预防胫骨应力性骨折提供重要参考。     

The Effect of Overuse Activity on Achilles Tendon in an Animal Model: A Biomechanical Study

Musculoskeletal soft tissue injuries from athletic activities are common in the rotator cuff tendons, lateral epicondyle of the elbow, the patella tendon, and the Achilles tendon. Despite the fact that the Achilles tendon is the largest and strongest tendon in the human body, it is frequently injured in the athletic setting. To study the etiology and pathogenesis of Achilles tendon injuries, our goal was to develop a model of Achilles tendon overuse by evaluating the Achilles tendons from animals subjected to the exercise protocol previously described as overuse for the supraspinatus tendon. We hypothesized that the same exercise protocol would produce injuries to the Achilles tendon as demonstrated by changes in the cross-sectional area and biomechanical properties. While a significant injury was induced into the supraspinatus tendon, we found no changes in the Achilles tendons of these exercised animals based on gross observation, geometric measurements, and mechanical testing analyses. Although surprising, there are many possible explanations for these findings including differences in potential injury mechanisms, functional capabilities of the differing tendons, and other factors.     

Motor Preparation: Changes in Amplitude of Achilles Tendon Reflexes During a Fixed Foreperiod of One Second

Achilles tendon (T) reflexes were evoked simultaneously in both legs during a fixed foreperiod of 1 sec. Volunteers were instructed to react as quickly as possible by one of four responses (in blocks): a plantar flexion of the left or right foot and a flexion of the left or right index finger. Prior to a foot response one leg was always involved in the response, prior to a finger response neither leg. Reflexes were evoked at 13 different points in time, from 100 msec prior to the warning signal (WS) to 100 msec after the response signal (RS). Amplitudes were expressed in percentages of control (intertrial interval) reflex amplitudes. In all conditions, amplitudes in both legs reached a peak 100 msec after the WS. After this non-selective increment, reflex amplitudes preceding a finger response decreased but remained larger than the baseline. Prior to a foot movement, amplitudes in uninvolved muscles remained larger than the baseline as well, whereas amplitudes in the involved muscle were no longer different from the baseline. This differential effect was independent of the response side. It was concluded that preparation for a response is characterized by a selective lack of activation in the reflex arc of the agonist, and a non-selective activation of the uninvolved spinal motor structures.     

Response of Rabbit Achilles Tendon to Chronic Repetitive Loading

The objective of this work was to assess the response of tendon to chronic repetitive loading. Controlled muscle stimulation was used to load the rabbit Achilles tendon at a frequency of 1.25 Hz for two hours per day, three days per week for a period of 11 weeks. Average peak tendon force was 26 N during the protocol. The loading protocol did not modify the gross morphology of the tissue, nor its water content or cellularity. Increases in mRNA expression of collagen Type III and MMPs were observed, but no signs of injury were detected by histologic examination of tendon and paratenon structures. The lack of a detectable injury response suggests that the tendons were not loaded beyond their capacity for repair. Factors additional to mechanical loading such as aging, illness or stress may be necessary to produce pathology.     

The Banding Pattern of Rat Tail Tendon Freeze-Etched Collagen Fibril

Banding patterns of freeze-etched and replicated rat tail tendon collagen fibrils were studied. Better banding definition was obtained by freezing the samples without using a cryoprotectant and by prolonging etching. Under these conditions, the banding pattern was characterized by a sequence of elevated and depressed segments with a D-period of 65 nm, by two ridges at the margins of the elevations and by a third ridge at an intermediate point in the depressions.

A comparison between replicas and isolated negatively stained collagen fibril micrographs as well as densi-tometric determinations have allowed interpretation of the elevations and depressions as overlap and gap zones and of the three ridges as the main bands with higher molecular density.

Estimates, carried out on densitometric diagrams obtained from replicas, gave values which may represent a new parameter in the study of collagen banding and led to the calculation of a 0.55 D long gap zone and of a 0.45 D long overlap zone.     

工程化肌腱修复肌腱缺损后力学特性的组织学基础

探讨组织工程化肌腱修复肌腱缺损后体内愈合过程中力学特性的组织学基础。取罗曼鸡肌腱细胞 ,经体外培养、扩增 ,与可降解生物材料聚羟基乙酸筛网构建工程化肌腱 ;将其植入修复 2 0只罗曼鸡第二趾深屈肌腱0 .5～ 0 .8cm缺损。术后第 2、4、6、8周取材 ,对标本进行大体、组织学及生物力学测定。植入 2、4、6、8周 ,新生肌腱在大体形态、细胞及胶原纤维排列方式上与正常肌腱相似 ,但新生肌腱的胶原纤维束并未形成较多的沿肌腱长度方向的致密结构 (“塑形”) ,导致其最大张力增加缓慢 ,到 8周时为 15 .4 0± 10 .6 3N,仅达正常肌腱的 2 3 ;8周时最大张应变为 2 2 .4 9± 10 .2 1 ,比正常肌腱大 10。结果表明 ,单纯聚羟基乙酸作支架 ,材料降解过快 ,新生肌腱失去了正常的力学刺激 ,“塑形”能力差 ,其生物力学强度低。提示 ,保持新生肌腱形成过程中正常的力学刺激对新生肌腱的“塑形”可能是至关重要的。     

跟腱运动功能与生物力学特征的研究进展

跟腱是连接足跟和足跖屈肌的关键结构,主要承担运动时小腿三头肌肌力的传递,是下肢在跑、跳时有效完成力/能量储存和释放的关键。现阶段,着地过程中跟腱的非同源性载荷以及过载后的无法完全恢复是跟腱损伤的首要原因,然而,针对预防跟腱损伤的相关手段并不能达到完全康复的效果。针对跟腱的运动功能及其在国内外生物力学领域的应用进行综述,重新考量跟腱在人体跑、跳运动中所起的作用,包括运动中跟腱内/外力学因素的系统关系、训练跟腱的有效方案。积极提升跟腱的力学特性,改善跟腱承受力,使之在一个较优范围,并最终达到提高运动表现,从源头上减少跟腱损伤,将是未来探究跟腱力学运动功能的关键。     

Temperature Increases in the Human Achilles Tendon During Ultrasound Treatments With Commercial Ultrasound Gel and Full-Thickness and Half-Thickness Gel Pads

Context:

Although originally manufactured for use in diagnostic imaging of internal structures, 2-cm-thick gel pads are also used as conducting media for therapeutic ultrasound over areas with bony prominences. Research on the ability of these pads to conduct enough energy to adequately heat tissues has provided mixed results. However, this research has mainly been performed on the triceps surae muscle, an area over which gel pads are not typically used. We wondered how much heating might be produced if a thinner pad was used over a tendon.

Objective:

To compare temperature rises in the human Achilles tendon during ultrasound treatments using ultrasound gel, a 2-cm-thick pad, and a 1-cm-thick pad.

Design:

Cross-sectional study.

Setting:

University therapeutic modality laboratory.

Patients or Other Participants:

Forty-eight healthy volunteers (24 women, 24 men).

Intervention(s):

We inserted a rigid thermocouple 1 cm deep into the Achilles tendon. Ultrasound was delivered at the following settings: 3 MHz, continuous, 1 W/cm², 10 minutes.

Main Outcome Measure(s):

Temperature was recorded every 30 seconds for 10 minutes.

Results:

Temperature increased the most in the ultrasound gel group (increase  =  13.3°C, peak  =  42°C). The 1-cm-thick pad resulted in higher tendon temperature (increase  =  9.3°C, peak  =  37.8°C) than the 2-cm-thick pad (increase  =  6.5°C, peak  =  4.8°C). The 1-cm pad produced approximately 30% more heating than the 2-cm pad (SE  =  0.72, P < .03).

Conclusions:

The thinner pad transmitted ultrasound more efficiently than the thicker pad. Thus, a gel pad of less than 1-cm thickness might be useful for superficial areas, such as the hands and ankles.     

Glycine Improves Biochemical and Biomechanical Properties Following Inflammation of the Achilles Tendon

Tendinopathy of the Achilles tendon is a clinical problem that motivates the scientific community to search for treatments that assist in restoring its functional properties. Glycine has broad biological effects, acting as a modulator of the inflammatory cascade, and is the predominant amino acid in collagen. A 5% glycine diet provided beneficial effects against toxicity and inflammation since glycine may restructure the collagen molecules faster due to its broad anti‐inflammatory effects. The purpose was analyze the effects of a 5% glycine diet in rats as a treatment for the inflammatory process. The experimental groups were as follows: C (control group), G1 and G3 (inflammatory group), and G2 and G4 (glycine + inflammatory group). G1 and G2 were euthanized 8 days following injury, and G3 and G4 were euthanized 22 days following injury. The concentrations of hydroxyproline, non‐collagenous proteins, and glycosaminoglycans, as well as the activity of MMP‐2 and ‐9 were analyzed. Biomechanical and morphological tests were employed. Higher concentrations of hydroxyproline and glycosaminoglycans were found in G4 and an increased activity of MMP‐2 was found in G2. Higher birefringence was noted in group G2. The biomechanical results indicated that the tendon was more resistant to loading to rupture upon treatment with a glycine diet in group G4. Glycine induced the synthesis of important components of the tendon. A rapid remodeling was noted when compared with the inflamed‐only groups. These data suggest that glycine may be a beneficial supplement for individuals with inflammation of the Achilles tendon. Anat Rec, 298:538–545, 2015. © 2014 Wiley Periodicals, Inc.     

Video-based Gait Analysis for Functional Evaluation of Healing Achilles Tendon in Rats

Video-based walking track systems have been developed for gait analysis in rat models. However, there is no previous study using video-based tracking systems to address the gait parameters to evaluate the recovery of Achilles tendon rupture models. This study conducted a comprehensive gait analysis using a video-based image processing system. Eighteen Sprague-Dawley rats were randomly assigned to one of three interventional conditions: sham surgery, Achilles tendon repair, and Achilles tendon defect. After surgery, all animals were evaluated using a video-based walking track system. The gait parameters and the Achilles functional index (AFI) were further analyzed. The ankle joint angles of the injury side at mid-stance and pre-swing were highly correlated with the AFI. However, lack of sensitivity was found for the AFI. Increased measurement sensitivity of the Achilles tendon healing condition was found in the ankle joint angle of the involved side at the pre-swing and the level of asymmetry of the hindlimb joint position and stance/swing time. The overall sensitivity of the ankle motion analysis was significantly higher than that of AFI. We conclude that the ankle motion analysis is a reliable, reproducible, and sensitive tool for Achilles tendon analysis in rats.     

健康教育对糖尿病足的干预效果

目的提高糖尿病患者并发症防护意识和自我护理能力,减少糖尿病足的发生。方法将100例糖尿病患者随机分成实验组和对照组,实验组对患者进行健康教育,对照组不进行健康教育。结果实验组对糖尿病知识掌握、信念和态度改变、产生健康行为、各项指标控制理想率均明显优于对照组(P<0.05)。结论通过对糖尿病患者进行系统的防护知识健康教育,改变了态度与行为,增强了自我保健意识和自我护理能力,提高了糖尿病患者生存质量。