College of Sports Medicine, Wuhan Sports University, Wuhan, China.
School of Sports Medicine and Rehabilitation, Beijing Sport University, Beijing, China.
Am J Sports Med. 2023 Dec;51(14):3835-3844. doi: 10.1177/03635465231202901. Epub 2023 Oct 20.
Various muscle contraction modalities have differing effects on the musculoskeletal system. To understand the magnitude of these effects, the authors investigated the effects of eccentric and concentric contractions on the bone-tendon interface after rotator cuff repair in mice.
Eccentric contraction promotes healing of the bone-tendon interface after rotator cuff repair in mice better than other muscle contraction patterns.
Controlled laboratory study.
The authors performed acute supraspinatus tendon repair of the right shoulder in 104 C57BL/6 mice. Animals were randomized into 4 groups postoperatively: control group (Con group), horizontal running group (Horz group), +15° uphill running group (Up group), and -15° downhill running group (Down group), with 26 animals in each group. At 4 and 8 weeks postoperatively, the authors removed the eyeball, collected blood samples, and extracted the supraspinatus tendon-humerus complex for histological, immunological, bone morphological, and biomechanical tests.
At 4 and 8 weeks postoperatively, the Down group exhibited a better collagen cell arrangement and fibrocartilage layer than the other 3 groups. At 4 weeks postoperatively, anti-inflammatory macrophages (M2 macrophages) were observed at the repair site in all groups except for the Con group. At 8 weeks postoperatively, M2 macrophages were withdrawn from the tendon site in all groups. The transforming growth factor β1 concentration in the Down group was greater than that in the other 3 groups at 4 weeks postoperatively, and it was higher than that in the Con group at 8 weeks postoperatively. The bone volume fraction, number of trabeculae, and thickness of trabeculae at the repair site in the Down group, as well as the ultimate strength and failure load in the biomechanical tests, were greater than those in the other 3 groups at 8 weeks postoperatively.
Eccentric contraction promotes healing of the bone-tendon interface after rotator cuff repair in mice better than other muscle contraction patterns.
After clinical rotator cuff repair, patients can be rehabilitated by eccentric training to speed up the functional recovery of the shoulder joint.
各种肌肉收缩方式对骨骼肌肉系统有不同的影响。为了了解这些影响的程度，作者研究了在小鼠肩袖修复后，离心和向心收缩对腱骨界面的影响。
与其他肌肉收缩模式相比，离心收缩更能促进小鼠肩袖修复后的腱骨界面愈合。
对照实验室研究。
作者对 104 只 C57BL/6 小鼠进行了右侧冈上肌腱急性修复。动物术后随机分为 4 组：对照组（Con 组）、水平跑步组（Horz 组）、+15°上坡跑步组（Up 组）和-15°下坡跑步组（Down 组），每组 26 只动物。术后 4 周和 8 周，作者取出眼球，采集血样，并提取冈上肌腱-肱骨复合体进行组织学、免疫学、骨形态学和生物力学测试。
术后 4 周和 8 周，Down 组胶原细胞排列和纤维软骨层优于其他 3 组。术后 4 周，除 Con 组外，所有组的修复部位均可见抗炎巨噬细胞（M2 巨噬细胞）。术后 8 周，所有组的 M2 巨噬细胞均从肌腱部位撤出。术后 4 周，Down 组转化生长因子β1 浓度大于其他 3 组，术后 8 周高于 Con 组。Down 组修复部位的骨体积分数、小梁数和小梁厚度以及生物力学测试中的最大强度和失效载荷均大于其他 3 组。
与其他肌肉收缩模式相比，离心收缩更能促进小鼠肩袖修复后的腱骨界面愈合。
在临床肩袖修复后，患者可以通过离心训练来康复，以加快肩关节的功能恢复。
