Sports biomechanics is a strong experimental frontier branches of science and aims to study human body motion,to explore human motion rule by human anatomy,human physiology,mechanics theories and methods. Studies on muscle mechanics are basis of studying sports biomechanics and movement training. Muscular mechanical property is very complex,and related to composition of muscle. Under different sports conditions,biomechanics characteristics of skeletal muscle are different,so the sports injuries are varied.

Sports biomechanics, as a branch of biomechanics, studies mechanics characteristics and mechanics relationship of human internal locomotor system and human external bodily movement to fundamentally understand the rule of biomechanics characteristics under the sports condition. Muscular function and mechanics characteristics are a basis of human motion, and muscle mechanics is a basis of sports biomechanics research and sports training.

Joint ligament injury often occurs in basketball sports,therefore,research on characteristics of joint cruciate ligament injury is helpful for the prevention and therapy for joint ligament injury.The manuscript introduces the biomechanical characteristics of knee joint cruciate ligament in the moving state,biological problems involved in repair,as well as the application of artificial ligament in knee joint crucriate ligament injury and its advantages and disadvantages.Various kinds of artificial ligament can be used for the repair of ligament injury,such as polyhexene,poly(ethylene terephthalate),carbon fibers,polyester,polydioxnon,polylactic acid.If we can perfect the artificial ligament,it will be more beneficial to its application in repair of ligament injury.

A Basketball sport is characterized by high exercise intensity, intense antagonism, many physical contacts, and agility. A series of injuries occurs in basketball sports. Tendon adhesion following basketball sports injury is a big problem puzzling athletes for a long time, which affect training and sport technique. Many scholars has been engaged in studying the methods prevent tendon adhesion following basketball sports injury. The article reviews the preventive effects of several biomaterials, such as chitosan, absorbable anti-adhesive film, sodium hyaluronate, polylactic acid, on tendon adhesion following basketball sports injury.

ObjectiveTo compare the difference effects on the proximal stomach in rapid(intake rate 100 mL/min) and slow(intake rate 15 mL/min) LNLT.Methods Forty healthy subjects received both the rapid and slow LNLTs.The caloric density of the nutrient was 1 kcal/mL. The TVDRI and MVDRI were recorded,and the corresponding TVPS and MVPS were measured by B-ultrasound.Results(1) There were positive correlation was identified between TVDRI and TVPS,and between MVDRI and MVPS in both slow and rapid LNLTs.(2) TVDRI and MVPS in slow LNLT were significantly smaller than those in rapid LNLT,but MVDRI was significantly larger in slow LNLT than that in rapid LNLT.(3) TVDRI was much closer to TVPS in slow LNLT than those in rapid LNLT.But MVDRI was much closer to MVPS in rapid LNLT than those in slow LNLT.Conclusion Both slow and rapid LNLTs could be used to evaluate the accommodation to a meal and visceral sensitivity of the proximal stomach.The visceral sensitivity is related to the accommodation function.TVDRI of slow LNLT is more sensitive in estimating the visceral sensitivity of the proximal stomach;MVDRI of rapid LNLT is more accurate in estimating the accommodation of the proximal stomach.

AIM To investigate whether the relaxation characteristics of phytoestrogens resveratrol and phloretin on contractile response of aortic strips are similar to that of estrogen and the mechanisms underground. METHODS Aortic strips from rabbits were suspended in organ baths containing Krebs solution, and then isometric tension was measured. RESULTS Resveratrol and phloretin inhibited the contractile responses to norepinephrine (NE), KCl and CaCl2, shifted their concentration-response curves rightward with pD2′ values of 2.89, 3.34, 3.37 for resveratrol and 3.23, 3.52, 3.77 for phloretin respectively. Also both of them concentration-dependently relaxed KCl-precontracted aortic strip. The relaxing response of resveratrol but not of phloretin in aortic strip was significantly reduced by removal of endothelium or incubation with Nω-L-nitro-arginine and methylthioninium chloride, however both their relaxant effects were not affected by indometacin and propranolol. In Ca2+-free Krebs solution containing 0.01 mmol·L-1 EGTA, resveratrol and phloretin inhibited NE-induced contraction which was caused by Ca2+ release from intracellular store, but did not affect the contraction which was induced by Ca2+ influx. CONCLUSION Resveratrol and phloretin can induce vasorelaxations which may relate to inhibition of Ca2+ influx through potential-dependent calcium channels and Ca2+ release from intracellular stores, and the relaxing response of resveratrol is endothelium-dependent in part, but of phloretin is not endothelium-dependent.

Objectives To investigate the clinical features of progressive familial intrahepatic cholestasis type 2 (PFIC2) and to illustrate the importance of genetic diagnosis. Methods The mutations in 27 exons of ABCB11 encoding bile salt export pump (BSEP) were identiifed using polymerase chain reaction (PCR) and direct DNA sequencing in 6 children with suspected PFIC2. The pathogenicity of the newly identiifed mutations were predicted by SIFT, PolyPhen-2, SNPs&GO software. The clini-cal features and laboratory examinations were reviewed. Results Four disease-causing mutations, p.R928*, p.E554K, p.R575Q and p.Y337H were identiifed, and the last three mutations were novel. These three kinds of novel mutations can cause the disease. Two children with genetic diagnosis had such manifestations as onset within a month after birth, jaundice, hepatosplenomegaly, upset, increased levels of total bilirubin and direct bilirubin, GGT<100 U/L and high levels of total bile acid. Conclusions Genetic diagnosis is a potent tool for clinical diagnosis of PFIC2.

Objective:To study the effects of group counseling which based on interpersonal activities and aimed at the college students with computer gaming addiction in China.Methods:Seventeen college students with computer game addiction were chosen as the experimental group,and 10 college students from another college were chosen as the control group.The two groups had no difference in the scores of Computer Gaming Addiction Invention(CGAI)and several other scales before group counseling.There were a pre-test and a post-test separately set when the group counseling was started and finished,focused on CGAI and negative emotions and cognitions.Results:In post-test,the score of CGAI in experimental group was significantly lower than that in control group[(92.6±16.7)vs.(105.9±13.0)] and lower than that in pre-test(98.9±16.4)by analysis of covariance(Ps<0.01).The scores of Beck Depression Inventory(BDI),Self-Rating Anxiety Scale(SAS),and the negative cognition of oneself in socical settings in experimental group were also lower than those in control group [(6.4±7.9)vs.(13.5±5.6),(39.7±6.4)vs.(49.9±10.3),(15.1±4.3)vs.(19.9±3.0),Ps<0.01],while the score of Rosenberg Self-Esteem Scale(SES)was higher than that of the control group [(29.3±2.9)vs.(24.6±4.8),P<0.01].Conclusion:Group counseling based on interpersonal activities has obvious effects on the college students with computer gaming addiction.

Objective:To summarize the oblique branches found in the transfer of anterolateral thigh flap (ALTF) and to handle the issues of oblique branch.Methods:Thirty patients who require surgery of ALTF transfer from May, 2017 to October, 2019 were enrolled. CTA examination was perfected prior surgery and the origin of ALTF vessels was preliminarily determined. During the surgery, Three-longitudinal-and-five-transverse methods were used to locate and design the flap. The ALTF was taken according to the flap design. Attention should be paid to the location of the oblique branch and the separation of the vessels of oblique branch to avoid a damage as much as possible. The vessels of oblique branch should be completely explored and separated. One or 2 vascular pedicles were cut according to whether the oblique branch vessels and the descending branch vessels were joined together during surgery. Clamping tests were carried out on the 2 vascular pedicles to determine an arterial blood supply. Super drainage of vascular pedicle veins according to the situation of blood circulation. After the surgery, routine treatment was carried out. Blood supply, skin temperature, swelling degree, exudation and survival of the flap were closely observed and regular follow-up was carried out.Results:Among the 30 ALTF examined by CTA, 13 patients were identified with oblique branch vessels before operation. During operation, 11 oblique branch vessels (The occurrencce rate was 36.6%)were found to enter the flap, and were completely preserved. Of the 11 identified oblique branch vessels, 8 had 2 vascular pedicles taken and the vascular pedicles were treated by venous super drainage technique. The postoperative blood supply of the flap was good; The skin temperature was closed to surrounding normal skin; Swelling of flap was minor and there was little seepage. The flaps all survived after surgery with stage one healing. Followed-up time was 3-32 (average 16.1) months. The recipient site healing was good, and the function and appearance were satisfactory. The joint movement at the donor site was normal, and there was no obvious loss of local sensation.Conclusion:More than one third of the oblique branches appear in this group. The oblique branch vessels should be preserved as much as possible to avoid issues in relation to the oblique branch. Reasonable handling of oblique branch is the key to the success of the surgery.

Objective To investigate the differences in sex hormone levels between hypospadias and circumcision groups.Methods Fifty cases of circumcision and 137 cases of hypospadias the dihydmtestosterone (DHT) value was tested with radioimmunoassay,and testosterone was tested with lightimmunoassay.Results DHT value was (64.51 ±32.10)pg/ml in circumcision group,and (46.72 ±28.94)pg/ml in hypospadias group (P ＜0.05).DHT value in hypospadias type Ⅰ,Ⅱ,Ⅲ,and Ⅳ were (50.20 ±32.90)pg/ml,(46.63 ±25.67)pg/rnl,(51.60 ±32.16)pg/ral,and (39.02 ±26.32)pg/ml,respectively (P =0.29).The differences between circumcision and hypospadias groups were statistically significant (P =0.00).Luteinizing hormone (LH) and testosterone (T) in children with hypospadias were significantly lower than those in children in the circumcision group (P ＜ 0.05).No statistically significant difference was found between two groups in follicle-stimulating hormone (FSH),estradiol (F2),and prolactin (PRL) (P ＞ 0.05).No statistically significant differences were found in FSH among all types of hypospadias (P ＞ 0.05).Conclusions Inadequate secretion of T or activity insufficiency and functional deficiency of 5 alpha reductase (SRD5A) are likely found in children with hypospadia.Inadequate secretion and low T value might be found in LH-T shaft in children with hypospadia.The normal T value in some children with hypospadia does not show that androgens produced during pregnancy are normal.