Journal of biomechanics最新文献_第2页

Biomechanical evaluation of the porcine carpus as a potential preclinical animal model for the human carpus 将猪腕骨作为人类腕骨的潜在临床前动物模型进行生物力学评估。

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2024-11-12 DOI: 10.1016/j.jbiomech.2024.112429

Madison K. Altieri , Rohit Badida , Quianna M. Vaughan , Janine Molino , Edward Akelman , Joseph J. Crisco

Advancing successful treatments for carpal instabilities of the wrist are hindered due, in part, to limited preclinical animal models. The purpose of this study was to evaluate the forelimb of the Yucatan minipig (YP) as a potential preclinical animal model for the human wrist by quantifying carpal biomechanics in vitro in the intact and after two ligament transection conditions. Porcine wrist biomechanics (n = 12, 5M, 7F) were determined in 28 range of motion (ROM) directions, in pronation-supination, and in volar-dorsal translation using a six-axis robotic musculoskeletal simulator. Testing was implemented in three conditions – intact, and after sequential transection of the radial intermediate ligament (RIL) and the dorsal intercarpal ligament (DIC). Mixed models were employed to examine differences in direction and conditions among male and female specimens. The intact ROM envelope was elliptical in shape and oriented toward ulnar flexion with the largest ROM about 15° from the flexion–extension axis. Transection of RIL and DIC did not alter the ROM envelope orientation, however, subtle increases in ROM were observed in extension and radial deviation following transection of both RIL and DIC. Pronation in neutral was greater than supination in all three test conditions. Volar translation increased subtly in the RIL and DIC condition. This novel study investigated the multidirectional biomechanics of the YP forelimb. ROM in the general directions of extension, radial and ulnar deviation were less than in humans, while flexion was substantially larger. These specific ligament transections had minor effects on the biomechanics of the YP forelimb.

临床前动物模型有限是阻碍成功治疗腕关节失稳的部分原因。本研究旨在评估尤卡坦小型猪（Yucatan minipig，YP）前肢作为人类腕部潜在临床前动物模型的可能性，方法是在体外对腕关节生物力学进行量化，包括完整状态和两种韧带横断后的状态。使用六轴机器人肌肉骨骼模拟器测定了猪腕部（n = 12，5M，7F）在 28 个运动范围 (ROM) 方向、前屈-上屈和外侧-背侧平移中的生物力学特性。测试在三种条件下进行--完好无损以及连续切断桡侧中间韧带（RIL）和背侧腕间韧带（DIC）后。混合模型用于研究男性和女性样本在方向和条件上的差异。完整的ROM包膜呈椭圆形，朝向尺侧屈曲，最大ROM与屈伸轴线相差约15°。RIL和DIC的横断并没有改变ROM包膜的方向，但是，在RIL和DIC横断后，伸展和桡侧偏离的ROM都有细微的增加。在所有三种测试条件下，中立位时的前伸均大于后仰。在 RIL 和 DIC 条件下，腓骨平移有微妙的增加。这项新颖的研究调查了YP前肢的多方向生物力学。在伸展、桡侧和尺侧偏离等一般方向上的ROM小于人类，而屈曲方向上的ROM则大得多。这些特定的韧带横断对翼手龙前肢的生物力学影响较小。

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引用次数: 0

Image-based finite element model stiffness and vBMD by single and dual energy CT reconstruction kernel 通过单能量和双能量 CT 重建内核建立基于图像的有限元模型刚度和 vBMD。

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2024-11-12 DOI: 10.1016/j.jbiomech.2024.112426

Nikolas K. Knowles, Sarah Quayyum, Jonathan Ying, Chloe Stiles, Daniel Beshay

Single-energy quantitative computed tomography (SEQCT) provides volumetric bone mineral density (vBMD) measures for bone analysis and input to image-based finite element models (FEMs). Dual-energy CT (DECT) improves vBMD by accounting for voxel-specific material variations utilizing scans at multiple x-ray energies. vBMD is also altered by reconstruction kernel that cannot be accounted for using calibration phantoms. This study compared vBMD and FEM stiffness derived from SEQCT and DECT images reconstructed with two common kernels. SEQCT and DECT images of cadaveric shoulders (n = 10) were collected using standard (STD) and boneplus (BONE) kernels. Hounsfield Units were converted to vBMD using specimen-specific calibrations. DECT STD and BONE images were generated using an established material decomposition method with 40 and 90 keV simulated monochromatic images. A proximal humerus bone section below the anatomic neck was used for vBMD analysis and FEM generation. FEMs were loaded to 1% apparent strain for stiffness measurements.

Between STD and BONE kernel images, average vBMD differed 0.9 mg_K2HPO4/cc and 4.1 mg _K2HPO4/cc, in SEQCT and DECT images, respectively. Significant differences occurred in DECT images (p = 0.001). BONE reconstructed images produced higher vBMD measures across both SEQCT and DECT images. The difference between STD and BONE in both SEQCT- and DECT-based FEMs persisted, with larger estimated stiffness in BONE models. For six of the models DECT-based had higher stiffness than SEQCT-based models using the same kernel, although these models differed between STD and BONE kernels. Differences in stiffness between STD and BONE derived models were similar across image types (DECT: 17.5 kN/mm; SEQCT: 19.0 kN/mm). Stiffness values were significantly different within SECT kernels and between SEQCT BONE and DECT STD models. This study shows important differences in vBMD and FEM stiffness that occur due to CT-based imaging parameters alone. These results indicate that consistent imaging parameters should be used for vBMD analysis and FEM input to avoid systematic measurement errors.

单能量定量计算机断层扫描（SEQCT）为骨分析和基于图像的有限元模型（FEM）输入提供了体积骨矿物质密度（vBMD）测量值。双能量 CT（DECT）通过利用多种 X 射线能量扫描来考虑特定体素的材料变化，从而改善了 vBMD。本研究比较了用两种常见内核重建的 SEQCT 和 DECT 图像得出的 vBMD 和 FEM 硬度。使用标准（STD）和骨加（BONE）内核采集了尸体肩部（n = 10）的 SEQCT 和 DECT 图像。使用特定标本校准将 Hounsfield 单位转换为 vBMD。DECT STD 和 BONE 图像是使用 40 和 90 keV 模拟单色图像的既定材料分解方法生成的。解剖颈部以下的肱骨近端截面用于 vBMD 分析和有限元模型生成。有限元加载到 1%的表观应变，用于刚度测量。在 STD 和骨核图像之间，SEQCT 和 DECT 图像的平均 vBMD 分别相差 0.9 毫克 K2HPO4/cc 和 4.1 毫克 K2HPO4/cc。DECT 图像存在显著差异（p = 0.001）。在 SEQCT 和 DECT 图像中，骨重建图像的 vBMD 测量值更高。在基于 SEQCT 和 DECT 的有限元模型中，STD 和 BONE 之间的差异持续存在，BONE 模型的估计硬度更大。在六个模型中，使用相同的核，基于 DECT 的模型比基于 SEQCT 的模型具有更高的硬度，尽管这些模型在 STD 和 BONE 核之间存在差异。在不同的图像类型中，STD 和 BONE 衍生模型之间的硬度差异相似（DECT：17.5 kN/mm；SEQCT：19.0 kN/mm）。在 SECT 内核以及 SEQCT BONE 和 DECT STD 模型之间，刚度值存在明显差异。这项研究表明，仅基于 CT 的成像参数会导致 vBMD 和 FEM 硬度出现重大差异。这些结果表明，vBMD 分析和有限元模型输入应使用一致的成像参数，以避免系统性测量误差。

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引用次数: 0

Effect of joint angle positioning on shearwave speed and variability with ultrasound shearwave elastography in asymptomatic Achilles and patellar tendons 关节角度定位对无症状跟腱和髌腱超声剪切波弹性成像的剪切波速度和变异性的影响。

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2024-11-12 DOI: 10.1016/j.jbiomech.2024.112427

Rachana Vaidya , Stephane Cui , Bryson Houston , Andrew North , Menghan Chen , Josh Baxter , Jennifer A. Zellers

This study investigated the impact of joint positioning on ultrasound shear wave elastography measurements in the Achilles and patellar tendons. Twenty-eight healthy adults underwent SWE assessment of shear wave speed (SWS) and coefficient of variation in SWS (CV-SWS) at three ankle positions (neutral, 10° plantar flexion, and 20° dorsiflexion) and two knee positions (90° flexion and full extension), at two academic sites. Participant positioning for ankle testing differed between sites (prone vs long-sitting)—while knee testing used consistent positioning. At the ankle, both joint and participant positioning significantly affected SWS. In the prone position, SWS was lower in neutral compared to dorsiflexed position (3.07 ± 1.13 m/s vs. 3.95 ± 1.03 m/s, p = 0.013). In long-sitting, SWS was lower in neutral compared to plantarflexed position (2.85 ± 0.53 m/s vs. 4.86 ± 1.92 m/s, p = 0.016); and SWS was higher in the plantarflexed position when participants were in long-sitting compared to prone (4.86 ± 1.92 m/s vs. 3.25 ± 1.13 m/s, p = 0.016). Participant positioning affected CV-SWS, with higher variability observed in prone compared to long-sitting in plantarflexed (29.3 ± 15.5 % vs 12.4 ± 9.12 %, p = 0.005) and neutral ankle angles (p = 0.03).

At the knee, joint position significantly influenced SWS, with higher values in flexed versus extended positions (6.48 ± 3.1 m/s vs. 4.60 ± 2.3 m/s, p = 0.007). Extending the knee reduced CV-SWS compared to flexed position (14.5 ± 11.2 vs 19.2 ± 13.4, p = 0.044). In conclusion, joint position significantly affected SWS measurements in both the Achilles and patellar tendons, while participant positioning influenced measurement variability. Thus, standardizing joint and participant positioning is important to enhance the reliability of SWE assessments of tendon elasticity.

本研究探讨了关节位置对跟腱和髌腱超声剪切波弹性成像测量的影响。28 名健康成年人在两个学术机构接受了三种踝关节位置（中立、10°跖屈和 20°背屈）和两种膝关节位置（90°屈曲和完全伸展）的剪切波速度（SWS）和 SWS 变异系数（CV-SWS）的 SWE 评估。参加者在踝关节测试时的体位在不同地点有所不同（俯卧位与长坐位），而膝关节测试则采用一致的体位。在踝关节测试中，关节和参与者的体位对 SWS 有明显影响。俯卧位时，中立位的 SWS 低于背屈位（3.07 ± 1.13 m/s vs. 3.95 ± 1.03 m/s，p = 0.013）。在长坐位时，与跖屈位相比，中立位的 SWS 更低（2.85 ± 0.53 m/s vs. 4.86 ± 1.92 m/s，p = 0.016）；与俯卧位相比，当参与者处于长坐位时，跖屈位的 SWS 更高（4.86 ± 1.92 m/s vs. 3.25 ± 1.13 m/s，p = 0.016）。参与者的体位会影响 CV-SWS，在跖屈（29.3 ± 15.5 % vs 12.4 ± 9.12 %，p = 0.005）和中立踝角（p = 0.03）时，俯卧位比长坐位的变异性更高。膝关节的关节位置对 SWS 有明显影响，屈曲位置的 SWS 值高于伸展位置的 SWS 值（6.48 ± 3.1 m/s vs. 4.60 ± 2.3 m/s，p = 0.007）。与屈膝姿势相比，伸膝姿势降低了 CV-SWS（14.5 ± 11.2 vs 19.2 ± 13.4，p = 0.044）。总之，关节位置对跟腱和髌腱的 SWS 测量有明显影响，而参与者的位置则影响测量的变异性。因此，关节和参与者定位的标准化对于提高肌腱弹性 SWE 评估的可靠性非常重要。

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引用次数: 0

Levodopa-induced dyskinesia alters postural control in people with Parkinson’s disease 左旋多巴诱发的运动障碍会改变帕金森病患者的姿势控制能力

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2024-11-09 DOI: 10.1016/j.jbiomech.2024.112421

Joseph Ayotunde Aderonmu, Carolin Curtze

While levodopa is the most effective drug for symptom treatment of Parkinson’s Disease (PD), its long-term use often leads to side effects such as uncontrolled involuntary movements known as levodopa-induced dyskinesia (LID). LID has been shown to increase postural sway, but the extent to which these hyperkinetic movements alter postural sway strategies has not been explored. We recruited 25 people with idiopathic PD, of which 13 exhibit clinical signs of LID, and 10 healthy older adults. Participants performed thirty-second standing trials with no added task (single-task) and with performing a cognitive dual-task, known to provoke dyskinesia. Participants with PD were tested in their practical OFF and ON states. The root-means-square (RMS) accelerations were obtained from inertial sensors attached to the lumbar, trunk, and head. Sway ratios (superior-to-inferior segment) were calculated to determine the effect of LID on postural sway strategies. Participants with LID showed greater RMS head sway, compared to those without LID and older adults. The head-to-trunk sway ratio was greater in participants with LID during the ON state or when dual-tasking. In addition, the head-to-lumbar sway ratio was greater in participants with LID in the ON state during both single- and dual-tasking. Our results reveal an altered postural control strategy in PD with LID, presenting increased sway in superior segments of the kinematic chain, leading to head instability. Unlike PD without LID and older adults, PD with LID exhibit multi-link sway in the ON state, which has important implications for measuring postural sway in the presence of dyskinesias.

虽然左旋多巴是治疗帕金森病（PD）症状的最有效药物，但长期使用左旋多巴往往会导致一些副作用，如不受控制的不自主运动，即左旋多巴诱发的运动障碍（LID）。研究表明，左旋多巴诱发的运动障碍会增加姿势摇摆，但这些过度运动会在多大程度上改变姿势摇摆策略，目前还没有研究。我们招募了 25 名特发性帕金森病患者（其中 13 人表现出 LID 的临床症状）和 10 名健康的老年人。参加者在没有附加任务（单一任务）的情况下进行了三十秒的站立试验，在进行认知性双重任务的情况下进行了三十秒的站立试验，众所周知，认知性双重任务会引起运动障碍。患有运动障碍的参与者在实际的 "关闭 "和 "开启 "状态下接受测试。加速度均方根（RMS）由腰部、躯干和头部的惯性传感器获得。通过计算摇摆比（上段与下段）来确定 LID 对姿势摇摆策略的影响。与没有 LID 的人和老年人相比，有 LID 的参与者头部摇摆的有效值更大。有 LID 的参与者在开启状态或双重任务时的头躯干摇摆比更大。此外，在单任务和双任务的开启状态下，有 LID 的参与者的头腰摇摆比更大。我们的研究结果表明，患有 LID 的帕金森病患者的姿势控制策略发生了改变，运动链上段的摇摆增加，导致头部不稳定。与无运动障碍的帕金森氏症患者和老年人不同，患有运动障碍的帕金森氏症患者在ON状态下表现出多环节摇摆，这对于测量存在运动障碍时的姿势摇摆具有重要意义。

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引用次数: 0

Paradoxıcal effect of body mass index ranges on pedobarographic evaluatıon 体重指数范围对足底摄影评估的矛盾影响

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2024-11-07 DOI: 10.1016/j.jbiomech.2024.112419

Açıkgöz Tahsin , Nur Kakilli , Çiftdemir Mert , Ekuklu Galip , Nurettin Taştekin

Although there is evidence suggesting that obesity alters plantar pressure distribution, the specific effects of certain body mass index (BMI) ranges on pedobarographic measures in healty individuals has been poorly investigated. A cross-sectional study with 167 healthy participants was conducted to assess plantar pressure changes across 4 BMI ranges: Under/normal weight (NW), overweight (OW), obese (OB), severe obese (SO). Subjects walked on the Footscan® pressure plate at a self-selected speed, and peak plantar pressure (PPP), load rate, and contact area values were recorded. The foot was divided into 10 zones: hallux (T1), toes 2–5 (T2-5), metatarsals 1–5 (M1-M5), midfoot (MF), medial hindfoot (MH) and lateral hindfoot (LH). PPP underneath M2-M4 was lowest in the NW group (p = 0.011), and although PPP values for the SO group were lower than those for the OW and OB groups, these differences were not statistically significant. Load rate values of M2-M3 were lower in both the NW and SO groups (p = 0.008) compared to the OW and OB groups. In addition, the metatarsal load rate values for the SO group were generally lower than those for the NW group. The total metatarsal contact area of both the NW and SO groups was lower (p = 0.019) than that of the OW and OB groups in both feet. These findings suggest that as BMI increases, PPP, load rate, and contact area in the middle metatarsal region initially increase, stabilize early in obesity, and then decrease at advanced stages, indicating a shift of the load to the midfoot.

尽管有证据表明肥胖会改变足底压力的分布，但对于某些体重指数（BMI）范围对健康人足底压力测量的具体影响却鲜有研究。我们对 167 名健康参与者进行了一项横断面研究，以评估 4 种体重指数范围的足底压力变化：体重不足/正常（NW）、超重（OW）、肥胖（OB）和严重肥胖（SO）。受试者以自选速度在 Footscan® 压力板上行走，并记录足底压力峰值 (PPP)、负荷率和接触面积值。足部被分为 10 个区域：脚掌（T1）、脚趾 2-5（T2-5）、跖骨 1-5（M1-M5）、中足（MF）、后足内侧（MH）和后足外侧（LH）。西北组 M2-M4 下方的 PPP 值最低（p = 0.011），虽然 SO 组的 PPP 值低于 OW 组和 OB 组，但这些差异在统计学上并不显著。与 OW 组和 OB 组相比，NW 组和 SO 组的 M2-M3 负荷率值均较低（p = 0.008）。此外，SO 组的跖骨负荷率值普遍低于 NW 组。NW组和SO组的双脚总跖骨接触面积均低于OW组和OB组（P = 0.019）。这些发现表明，随着体重指数（BMI）的增加，中跖骨区域的PPP、负荷率和接触面积最初会增加，在肥胖早期会趋于稳定，然后在晚期会减少，这表明负荷转移到了中足。

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引用次数: 0

Effects of four weeks intervention combining high-definition transcranial direct current stimulation and foot core exercise on dynamic postural stability 结合高清经颅直流电刺激和足部核心运动的四周干预对动态姿势稳定性的影响。

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2024-11-07 DOI: 10.1016/j.jbiomech.2024.112418

Baofeng Wang , Bin Shen , Songlin Xiao , Junhong Zhou , Weijie Fu

This study aimed to evaluate the effect of combining high-definition transcranial direct current stimulation (HD-tDCS) with foot core exercise (FCE) on dynamic postural stability and to determine whether the improvement achieved through this mix-type intervention outperforms the intervention of HD-tDCS and FCE alone. Sixty healthy males were recruited and randomly divided into four groups: (1) HD-tDCS + FCE group (HD-tDCS combined with FCE intervention); (2) s-tDCS + FCE (sham tDCS combined with FCE intervention); (3) HD-tDCS group which only received HD-tDCS; (4) FCE group which only performed FCE. All participants received a four-week intervention (3 times a week, 20 min each time). The Y-balance task was completed before and after the intervention. The maximum reaching distance was recorded, and the data of the center of pressure (COP) were collected by a three-dimensional force plate to calculate COP displacement and velocity. No significant change in COP displacement was found among the four groups. However, the COP velocity decreased significantly in the posteromedial direction after HD-tDCS + FCE intervention compared with the baseline. The maximum reach distance was significantly increased after HD-tDCS + FCE intervention in the posteromedial (p < 0.001) and posterolateral (p < 0.001) directions of the Y balance task compared with the baseline, and the extent of increase was greater than that in the three other groups. The intervention of HD-tDCS combined with FCE may exert a synergistic effect and more effectively improve dynamic postural stability.

本研究旨在评估高清经颅直流电刺激（HD-tDCS）与足部核心锻炼（FCE）相结合对动态姿势稳定性的影响，并确定这种混合型干预所取得的改善效果是否优于单纯的 HD-tDCS 和 FCE 干预。研究人员招募了 60 名健康男性，并将其随机分为四组：（1）HD-tDCS + FCE 组（HD-tDCS 与 FCE 联合干预）；（2）s-tDCS + FCE 组（假 tDCS 与 FCE 联合干预）；（3）HD-tDCS 组，仅接受 HD-tDCS；（4）FCE 组，仅进行 FCE。所有参与者都接受了为期四周的干预（每周 3 次，每次 20 分钟）。干预前后均完成了 Y 平衡任务。记录最大伸手距离，并通过三维测力板收集压力中心（COP）数据，计算 COP 位移和速度。结果显示，四组患者的 COP 位移均无明显变化。然而，与基线相比，HD-tDCS + FCE 干预后 COP 速度在后内侧方向明显下降。HD-tDCS + FCE 干预后，后内侧的最大伸展距离明显增加（p

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引用次数: 0

Influence of custom dynamic orthoses on tibiotalar joint reaction force and contact stress: A cadaveric study 定制动态矫形器对胫骨关节反作用力和接触应力的影响：尸体研究

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2024-11-07 DOI: 10.1016/j.jbiomech.2024.112420

Lucinda Williamson , Marc Brouillette , Tristan Miller , Jessica Goetz , Jason Wilken , Donald D. Anderson

Post-traumatic osteoarthritis (PTOA) often develops following tibial pilon fractures. Evidence suggesting PTOA development is driven by elevated articular contact stress from residual malreduction has led surgeons to strive for precise articular reduction, typically at the cost of extended operative time. Post-operative bracing using carbon fiber custom dynamic orthoses (CDOs) offers another means to decrease tibiotalar joint reaction force (JRF) and contact stress. The purpose of this cadaveric study was to measure how CDO stiffness influences ankle JRF and contact stress over the stance phase of gait.

A servohydraulic load frame was used to test five cadaver ankles, with axial loading (240–330 N) and pneumatic actuation of the Achilles tendon (50–436 N) serving to quasi-statically model multiple points in the stance phase of gait. Three CDO rotational stiffness conditions were tested: (1) No CDO–0 Nm/deg, (2) low stiffness CDO–1.8 Nm/deg, and (3) moderate stiffness CDO–2.3 Nm/deg. JRF and contact stresses were measured using a piezoresistive pressure sensor inserted into the tibiotalar joint. An insole plantar pressure sensor placed between the cadaveric foot and CDO footplate measured limb/device interactions via the plantar center of pressure (COP).

As limb loading progressed through stance, the plantar COP progressed from hindfoot to forefoot, as it would in normal gait. Both CDOs demonstrated decreases in JRF, reaching as high as 32% for the low CDO and 26% for the moderate CDO, with associated decreases in contact stress. This suggests that post-operative bracing could lessen PTOA risk after pilon fractures.

胫骨皮隆骨折后经常会出现创伤后骨关节炎（PTOA）。有证据表明，PTOA 的发生是由于残留的不良还原引起的关节接触应力升高所致，这促使外科医生努力实现精确的关节还原，但这通常是以延长手术时间为代价的。使用碳纤维定制动态矫形器（CDO）进行术后支撑是降低胫骨关节反作用力（JRF）和接触应力的另一种方法。这项尸体研究的目的是测量 CDO 刚度如何影响步态站立阶段的踝关节反作用力和接触应力。研究人员使用伺服液压负载架测试了五个尸体踝关节，通过轴向加载（240-330 N）和跟腱气动驱动（50-436 N）对步态站立阶段的多个点进行了准静态模拟。测试了三种 CDO 旋转刚度条件：(1) 无 CDO-0 Nm/deg，(2) 低刚度 CDO-1.8 Nm/deg，(3) 中等刚度 CDO-2.3 Nm/deg。使用插入胫骨关节的压阻压力传感器测量 JRF 和接触应力。放置在尸体脚和 CDO 脚板之间的鞋垫足底压力传感器通过足底压力中心 (COP) 测量肢体/装置之间的相互作用。两种 CDO 都显示出 JRF 的下降，低度 CDO 高达 32%，中度 CDO 高达 26%，同时接触应力也随之下降。这表明，术后支撑可降低皮隆骨折后的 PTOA 风险。

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引用次数: 0

Bilateral symmetry assessment of healthy forearm kinematics using 4D-CT 利用 4D-CT 评估健康前臂运动学的双侧对称性。

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2024-11-06 DOI: 10.1016/j.jbiomech.2024.112417

Joris G.M. Oonk , Johannes G.G. Dobbe , Frederique T. van der Zeeuw , Loes Ettema , Gustav J. Strijkers , Geert J. Streekstra

Advanced stage distal radio-ulnar joint (DRUJ) injury may warrant radius corrective osteotomy or arthroplasty. These procedures aim to restore geometry, function and kinematics and could benefit from preoperative planning where the contralateral forearm is typically used as reference. Natural variations regarding geometry and function between forearms are known but kinematic differences are not. This work aimed to quantify bilateral differences in forearm kinematics. Consequently, 4D-CT data of ten healthy volunteers was acquired, imaging motion of both forearm joints. Segmentation and registration of the radius and ulna bones resulted in a 3D representation of forearm rotation. Subsequently, the forearm rotation axis, radius translation along the ulna and radius rotation around its own inertial axis were calculated. The rotation axis of the right arm was mirrored to set up a comparison with the left arm. All other differences were calculated directly. The mean angle and distance between forearm rotation axes were 0.6° and 0.8 mm. The mean difference in radius translation along the ulna was 0.9 mm. On average, radius rotation around the radius’ inertial axis differed 2.6°, between forearms. This study’s findings can benefit DRUJ surgery preoperative planning and postoperative kinematic evaluation.

Level of evidence: IV.

射血远端-尺关节（DRUJ）损伤晚期可能需要进行桡骨矫正截骨术或关节成形术。这些手术旨在恢复桡骨的几何形状、功能和运动学，术前规划通常以对侧前臂为参照物，可以从中获益。众所周知，前臂在几何和功能方面存在自然差异，但运动学差异却不为人所知。这项研究旨在量化前臂运动学的双侧差异。因此，我们采集了十名健康志愿者的 4D-CT 数据，对两个前臂关节的运动进行成像。对桡骨和尺骨进行分割和配准后，得到了前臂旋转的三维图像。随后，计算出前臂旋转轴、桡骨沿尺骨的平移以及桡骨绕自身惯性轴的旋转。右臂的旋转轴是镜像的，以便与左臂进行比较。所有其他差异均直接计算。前臂旋转轴之间的平均角度和距离分别为 0.6°和 0.8 毫米。桡骨沿尺骨平移的平均差异为 0.9 毫米。不同前臂围绕桡骨惯性轴的桡骨旋转平均相差 2.6°。这项研究的结果将有助于 DRUJ 手术的术前规划和术后运动学评估。证据等级：IV级。

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引用次数: 0

Passive-dynamic ankle-foot orthoses change post-stroke lower extremity constituent work profile 被动动态踝足矫形器改变了中风后下肢的工作状况。

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2024-11-04 DOI: 10.1016/j.jbiomech.2024.112414

Jacob T. Skigen , Corey A. Koller , Darcy S. Reisman , Zahra N. McKee , Shay R. Pinhey , Jason M. Wilken , Elisa S. Arch

Stiffness-customized passive-dynamic ankle–foot orthoses (PD-AFOs) have been shown to reduce the mechanical cost of transport (COT) of individuals post-stroke. However, the mechanisms underlying this reduced COT are unknown. Therefore, this study aimed to identify the factors driving COT reduction with PD-AFO use for individuals post-stroke. Results showed that changes in limb work were strongly correlated to changes in COT with the PD-AFO compared to No AFO in the paretic (tau = 0.637, p < 0.001) and non-paretic (tau = 0.621, p < 0.001) limbs. There was also a strong correlation between changes in limb work and changes in COT compared to SOC AFO in the paretic (tau = 0.569, p < 0.001) and non-paretic (tau = 0.503, p = 0.003) limbs. Conversely, changes in stride length and changes in COT were not correlated. Changes in COT between No AFO and PD-AFO were moderately correlated to the number of constituents that performed less mechanical work for both the paretic (tau = −0.462, p = 0.009) and non-paretic (tau = −0.402, p = 0.025) limbs. Compared to walking with SOC AFOs, there was a moderate correlation between COT and the number of constituents in the paretic limb (tau = −0.458, p = 0.011) but not the non-paretic limb (tau = −0.247, p = 0.173). These findings indicate that PD-AFOs reduce COT primarily through small changes in work across many lower limb constituents. Understanding how COT reduction occurs can help optimize PD-AFO design and possibly other rehabilitation interventions for individuals post-stroke.

僵硬度定制的被动动态踝足矫形器（PD-AFOs）已被证明可以降低中风后患者的机械运输成本（COT）。然而，降低运输成本的机制尚不清楚。因此，本研究旨在确定脑卒中后患者使用踝足矫形器降低运输成本的驱动因素。结果显示，与无AFO相比，使用PD-AFO后肢体工作的变化与瘫痪者COT的变化密切相关（tau = 0.637，p＜0.05）。

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引用次数: 0

Biomechanical properties of various rat rotator cuff repair techniques 各种大鼠肩袖修复技术的生物力学特性。

IF 2.4 3区医学 Q3 BIOPHYSICS

Journal of biomechanics

Pub Date : 2024-11-02 DOI: 10.1016/j.jbiomech.2024.112399

Mohamed Abozaid, Elameen Adam, Aida Sarcon, Kai-Nan An, Chunfeng Zhao

While rat models are frequently used to study tendon healing, there is a lack of research comparing various rotator cuff repair methods in this animal model. Determining the most effective method to begin with is pivotal for biological studies focused on healing augmentation. No study to date has shown the superiority of one repair over the other for rotator cuff repair in a rat model. We performed a biomechanic study using a rat model to study the strength of four common grasping techniques. We assessed if the bone tunnel trajectory influenced the early biomechanics of the repair at postoperative day 0 (POD0). Sixty cadaveric rat shoulders were divided equally into 6 groups; 4 groups were allocated for the biomechanical strength testing based on either a (1) modified Mason Allen (MM), (2) modified Kessler loop (MK), (3) horizontal mattress (HM), or a (4) simple interrupted stitch (SS) technique. The remaining 2 groups were used to evaluate two tunneling angles: a transverse tunnel (TT) that was perpendicular to the long humeral axis, or a longitudinal tunnel (LT) that was 30^◦ angle to the humerus. MM had the highest mean failure load, followed by MK, HM, and SS. Pairwise comparison revealed that MM was stronger than SS and HM (P = 0.025 and P = 0.026, respectively), although similar to the MK (P = 0.881). MM was stiffer than MK (P < 0.001), HM (P = 0.008), and SS (P < 0.001). The TT and LT had similar loads to failure and stiffness. Our study suggests that the MM technique provides a stronger and stiffer rotator cuff repair than the others.

虽然大鼠模型经常被用来研究肌腱愈合，但目前还缺乏在这种动物模型中比较各种肩袖修复方法的研究。确定最有效的方法对于以增强愈合为重点的生物学研究至关重要。迄今为止，还没有任何研究表明，在大鼠模型中进行肩袖修复时，一种修复方法优于另一种修复方法。我们利用大鼠模型进行了一项生物力学研究，研究了四种常见抓握技术的强度。我们评估了骨隧道轨迹是否会影响术后第 0 天（POD0）修复的早期生物力学。我们将 60 只尸体大鼠肩部平均分成 6 组，其中 4 组根据 (1) 改良梅森艾伦 (MM)、(2) 改良凯斯勒环 (MK)、(3) 水平床垫 (HM) 或 (4) 简单间断缝合 (SS) 技术进行生物力学强度测试。其余两组用于评估两种隧道角度：与肱骨长轴垂直的横向隧道（TT）或与肱骨成 30◦ 角的纵向隧道（LT）。MM的平均破坏载荷最高，其次是MK、HM和SS。配对比较显示，MM 的强度高于 SS 和 HM（分别为 P = 0.025 和 P = 0.026），但与 MK 相似（P = 0.881）。MM 比 MK 更硬（P

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引用次数: 0