Time-Pressure Curve Of Skeletal Muscle Injury In Rats Induced By Pressing Of Tuina

Background: Wu Yi tuina technique focuses on the therapeutic effect,and its force is larger（higher intensity）and the operation time is relatively short.Studies have pointed out that Wu Yi tuina technique have the characteristics of "powerful".However,excessive tuina force will cause injury to the patient,so the tuina force should not exceed the critical value of causing injury.It is particularly important to study the critical value of the injury caused by the force of tuina manipulation,and there is no previous research on the injury threshold of the injury caused by pressure in a short time.Objiective:To explore the effects of different time and pressure factors on rats during massage,analyze the damage threshold,and summarize the time-pressure-induced tissue damage curve.Methods: 39 SD rats were randomly divided into 13 groups,with 3 rats in each group,the double hind legs of each rat were used for the experiment,and there were 6 samples in each group.According to the characteristics of massage and pressing method,the pressure time in this experiment was set to 10 s and 30 s.According to the pressure time-pressure,the rats were divided into control group;10s-100 k Pa group,10s-200 k Pa group,10s-300 k Pa group,10s-400 k Pa group,10s-500 k Pa group,10s-600 k Pa group;30s-100 k Pa group,30s-200 k Pa group,30s-300 k Pa group,30s-400 k Pa group,30s-500 k Pa group,30s-600 k Pa group.A self-made pressure device was used to apply pressure to the medial middle of the left and right legs of the rats,and blood was collected from the orbit immediately,and serum lactate dehydrogenase（LDH）was detected with a fully automated analyzer;Statistical analysis was performed after quantitative counting of the muscle cell space and the cross-sectional area of a single muscle cell in the compressed area.Results:1.The effect of different time-pressure on the morphology of rat skeletal muscleIn the control group,the muscle cells of the rats were neatly arranged,the size was the same,the muscle cells had no rupture,necrosis,degeneration,the cell membrane was intact,the boundary was clear,the cytoplasm was uniform,the nucleus was normal,there was no hyperplasia,hypertrophy or pyknosis,no tissue edema and inflammatory cells.Infiltration,no fibrous tissue hyperplasia,no expansion and congestion,no bleeding,visible muscle striated.Under the same pressure,the 100～300k Pa group had no significant change compared with the control group,while the 400～600k Pa group compared with the control group showed obvious muscle fiber interstitial widening,blood cell leakage,and obvious vascular congestion;under the same pressure,There was no significant change between the 30 s and 10 s groups.2.The effect of different time-pressure on the intercellular space area of rat skeletal muscle（1）Under the action of pressure at the same time,compared with the control group,the area of skeletal muscle cells in the 400 k Pa group,500 k Pa group and 600 k Pa group increased significantly（P<0.01）.The area shows a gradually increasing trend,and the pressure range with differential changes is 300～400k Pa.（2）Under the same pressure,there was no significant difference in the area of skeletal muscle cells between the 10 s and 30 s groups（P>0.05）.3.The effect of different time-pressure effects on the cross-sectional area of a single muscle cell（1）Under the pressure at the same time,the cross-sectional areas of single muscle cells in the 400 k Pa,500 k Pa and 600 k Pa groups were significantly reduced compared with the control group（P<0.001）;single muscle cells in the 400 k Pa,500 k Pa and 600 k Pa groups The cross-sectional area was significantly smaller than the 100 k Pa group,the 200 k Pa group and the 300 k Pa group（P<0.05）.With the increase of pressure,the cross-sectional area of a single muscle cell gradually decreased,and the pressure range of differential changes was 300-400 k Pa.（2）Under the same pressure,there was no significant difference in the cross-sectional area of a single muscle cell between the 10 s and 30 s groups（P>0.05）.4.The effect of different time-pressure on serum LDH in ratsThere were significant differences between 10s-100 k Pa group,30s-100 k Pa group,10s-300 k Pa group and the control group（P<0.05）,and there was no significant difference between the other groups（P>0.05）.Compared with the control group,the serum LDH concentration in each group was higher.Conclusion:（1）The results of this study showed that under the action of 10 s and 30 s of compression,the damage threshold of rat muscle tissue was between 300 and 400 k Pa.（2）The results of this study show that under the action of short-term compression,the relationship between the damage of rat muscle tissue and strength is obvious,but the relationship with time is not obvious.