Effects of Footwear Selection on Plantar Pressure and Neuromuscular Characteristics during Jump Rope Training.

This study examined what footwear type influenced plantar pressure and lower extremity muscle activations in jump rope training. Ten healthy physical-education graduate students participated in this study. The biomechanical parameters during the jump rope training were collected by an AMTI force platform, a Novel Pedar-X insole and a wireless electromyography (EMG) system. The results of the force platform indicate that vertical ground reaction force (vGRF) and contact time were much higher in the one-leg landing (both p = 0.001). The GRF, GRF (BW) and Lat MF pressure were significantly greater in the one-leg landing (p = 0.018, 0.013 and 0.027); the pressure of the Lat MF and H area were significantly greater in the volleyball shoe (p = 0.025, 0.031); the pressure of the Mid FF and Lat FF area were significantly greater in the jumping shoe (p = 0.005, 0.042). No significant difference in EMG was found between footwear and landing conditions. In summary, the running shoe and jumping shoe might be a better choice for people who exercise. However, the running shoe is recommended for people when both jumping and running are required.

Scutellarin regulates osteoarthritis in vitro by inhibiting the PI3K/AKT/mTOR signaling pathway.

Osteoarthritis (OA) is a highly prevalent disease worldwide that causes disability and diminishes the quality of life of affected individuals. The disease is characterized by cartilage destruction, increased inflammatory responses and cholesterol metabolic disorder. Scutellarin is the major active ingredient extracted from Erigeron breviscapus, and it has been demonstrated to possess various pharmacological functions in the treatment of the disease. However, its effects on OA are complex. The present study investigated whether scutellarin can mediate the release of inflammatory cytokines, the expression of collagen- and cholesterol-related proteins, and regulate the phosphoinositide 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway in a cell model of OA. Interleukin (IL)-1ß was used to stimulate OA in SW1353 cells in vitro. The primary methods used were ELISA and western blotting, which were carried out to examine the effects of scutellarin on the cell model of OA. It was found that scutellarin increased the expression of collagen II and SRY-box 9, whereas it suppressed the expression of matrix metalloproteinase 13. In addition, scutellarin downregulated the expression levels of cholesterol 25-hydroxylase and cytochrome P450 family 7 subfamily B polypeptide 1, but upregulated the expression of apolipoprotein A-1 and adenosine triphosphate-binding cassette transporter A1. The IL-1ß-induced increase in the expression of IL-6 was decreased by treatment with scutellarin; however, scutellarin did not alter the expression of C-reactive protein and tumor necrosis factor-α. The protein expression levels of AKT, phosphorylated (p)-AKT, mTOR and p-mTOR in the PI3K/AKT/mTOR signaling pathway were decreased in the IL-1ß-induced SW1353 cells following scutellarin treatment. Overall, the findings of the present study demonstrated that scutellarin regulated OA in vitro by inhibiting the PI3K/AKT/mTOR signaling pathway.

[Progress on classification and application of artificial hip joint materials].

The selection of the prosthetic material determine the success or failure of hip arthroplasty. Currently, the metals, ceramics, polymer composites and carbon materials are the main prosthetic materials of artificial hip joint. They have some progresses in biocompatibility, elastic modulus,mechanical properties, useful life, but they still can't reach the ideal standard of design. In this essay, we mainly review the characteristics and applications of the current artificial hip joint materials through its classification in order to provide a reference for choosing appropriate hip joint materials in clinic and increasing characteristic of materials. We consider the polymer composites has more advantages such as biocompatibility, mechanical properties, corrosion resistance and price, even if it has shortages in abrasion resistance. As the researches of polymer composites are main focus on abrasion resistance, articular surface and strength,and its performances are increased fast, it has a wide prospect in future.

Mechanical properties and biocompatibility of melt processed, self-reinforced ultrahigh molecular weight polyethylene.

The low efficiency of fabrication of ultrahigh molecular weight polyethylene (UHMWPE)-based artificial knee joint implants is a bottleneck problem because of its extremely high melt viscosity. We prepared melt processable UHMWPE (MP-UHMWPE) by addition of 9.8 wt% ultralow molecular weight polyethylene (ULMWPE) as a flow accelerator. More importantly, an intense shear flow was applied during injection molding of MP-UHMWPE, which on one hand, promoted the self-diffusion of UHMWPE chains, thus effectively reducing the structural defects; on the other hand, increased the overall crystallinity and induced the formation of self-reinforcing superstructure, i.e., interlocked shish-kebabs and oriented lamellae. Aside from the good biocompatibility, and the superior fatigue and wear resistance to the compression-molded UHMWPE, the injection-molded MP-UHMWPE exhibits a noteworthy enhancement in tensile properties and impact strength, where the yield strength increases to 46.3 ± 4.4 MPa with an increment of 128.0%, the ultimate tensile strength and Young's modulus rise remarkably up to 65.5 ± 5.0 MPa and 1248.7 ± 45.3 MPa, respectively, and the impact strength reaches 90.6 kJ/m(2). These results suggested such melt processed and self-reinforced UHMWPE parts hold a great application promise for use of knee joint implants, particularly for younger and more active patients. Our work sets up a new method to fabricate high-performance UHMWPE implants by tailoring the superstructure during thermoplastic processing.

[Case-control study on isometric quadriceps femoris contraction exercises for the treatment of knee osteoarthritis].

OBJECTIVE: To evaluate clinical effects of knee osteoarthritis with the treatment of the isometric quadriceps femoris contraction exercises, which aims at establishing the exercise prescription of knee osteoarthritis,and promoting its clinical application. METHODS: From January 2008 to September 2010, 120 patients with knee osteoarthritis were divided into two groups according to visiting sequence, including 39 males and 81 females, ranging in age from 40 to 85 years, with an average of 62.50 years, the disease course ranged from 1 month to 30 years. There were 60 patients in the therapeutic group, including 21 males and 39 females, ranging in age from 40 to 85 years, with an average of (62.27 +/- 8.99) years, the disease course ranged from 2 months to 30 years; and the patients were treated with intra-articular injection of sodium hyaluronate and isometric quadriceps femoris contraction exercises for treatment. There were 60 patients in the control group; including 18 males and 42 females, ranging in age from 41 to 80 years, with an average of (62.72 +/- 8.34) years, the disease course ranged from 1 month to 30 years; and the patients were treated with conventional intra-articular injection of sodium hyaluronate. The index such as the pains,functions and articular dropsy of the knees were observed and the clinical effects were compared respectively. RESULTS: All the patients were followed up, and the duration ranged from 1 to 3 years, with an average of 18 months. According to standard of JOA about evaluating the therapeutic effects of knee osteoarthritis: in the therapeutic group, 12 patients got an excellent result, 33 good, 14 poor and 1 bad; and in the control group, 7 patients got an excellent result, 14 good, 31 poor and 8 bad. The clinical results of therapeutic group was better than that of control group. There were 7 recurrent cases in the therapeutic group and 31 recurrent cases in the control group; the recurrence rate in therapeutic group was lower than that of control group. CONCLUSION: The isometric quadriceps femoris contraction exercises has obvious effect in alleviating the symptoms, improving joint function, strengthening the joint stability and slowing down joint degeneration process for the treatment of knee osteoarthritis, which has a good effect in the long-term clinical effects.

[Comparison of clinical effects of various external fixation for the treatment of humeral supracondylar fracture].

OBJECTIVE: To compare clinical effects and the incidence rates of cubitus varus in displaced humeral supracondylar fractures treated with different kinds of external fixation. METHODS: Among 226 children with displaced humeral supracondylar fractures, 134 patients were male and 92 patients were female, ranging in age from 5 to 12 years, with an average of 8.58 years. After manipulative reduction, the patients were treated with three kinds of external fixation: the 88 patients (51 males and 37 females, ranging in age from 5.1 to 12 years) in Group A were treated with double external fixations of small splint and moulding splint; 74 patients (44 males and 30 females, ranging in age from 5 to 11.8 years) in Group B were treated with small splint; and 64 patients (39 males and 25 females, ranging in age from 5.5 to 12 years) in Group C were treated with plaster slab. The indexes such as healing time of fractures, the functions of elbow joint and cubitus varus were observed. The clinical effects and the incidence rates of cubitus varus in three groups were compared. RESULTS: All the patients were followed-up, and the duration of follow-up ranged from 6 months to 4 years, with an average of 25 months. According to the standard for efficacy evaluation, in Group A, 59 patients got an excellent result, 23 good, 6 bad, the excellent and good rate was 93.18%; in Group B, above data were 37, 29, 8, 89.19% respectively; while in Group C, the data were 20, 31, 13 and 79.69% respectively. The incidence rates of cubitus varus of three groups were 6.82%, 17.57% and 32.81% respectively. The result of statistical analysis demonstrated that there were significant differences of the clinical effects and the incidence rates of cubitus varus in three groups (P<0.05). Comparison of the clinical effects: Group A was better than Group B and Group C, Group B was better than Group C. The incidence rates of cubitus varus: Group A was lower than Group B and Group C, Group B was lower than Group C. CONCLUSION: The therapeutic effects of double external fixation is the best among three groups. The double external fixation had follow advantages: external fixation, high stability, strong anti-rotation ability, and joint function quick recovery, the incidence rates of cubitus varus lower and good clinical effects. So double external fixation method should be the first choose for the treatment of humeral supracondylar fractures.