Body movements on the men's competition mushroom: a three dimensional analysis of circular swings.

OBJECTIVES: To develop a method for the three dimensional analysis of body movements and body positions during the performance of circular swings on the competition mushroom, an apparatus used by young gymnasts for pommel horse training. METHODS: Five experienced male gymnasts, all of national level, performed three series of 10 circular swings on the competition mushroom. An optoelectronic instrument was used for the detection of the three dimensional movement of 13 body landmarks. From landmark trajectories, several technical measurements were obtained: diameters of ideal circles of ankles, hips, shoulders; deviation of the ankle diameters from circularity and from the horizontal plane; angle between the shoulder, hip, and ankle. The values were used for a quantitative assessment of performance of the five gymnasts. RESULTS: During the exercise, each ankle should follow a nearly horizontal circular path (deviation from circularity ranged from 3.6% to 6%, deviation from horizontality was 9.4-19.7%), there should be an angle of about 180 degrees at the hips (actual values 146-153 degrees ), and the shoulders should move as little as possible, and only in the lateral plane, without major anteroposterior movements (shoulder movement was 27-31% of ankle movement, hip movement was 16-20%). CONCLUSIONS: The method could help coaches and gymnasts to determine which parts of the body are not repeating a selected movement with sufficient accuracy and to quantify improvements made after a specific training programme.

Toll-like receptor agonists regulate beta-defensin 2 release in hair follicle.

BACKGROUND: Skin is constantly in contact with different pathogens, which are present in the environment. The hair follicle is particularly susceptible to this microbial invasion as it offers an easy way of access for microorganisms; for this reason it is equipped with defence mechanisms to avoid frequent infections. OBJECTIVES: To analyse the expression pattern of four different members of the toll-like receptor (TLR) family in murine hair follicles and to evaluate the effects of their activation by their specific microbiota-derived agonists, in terms of production of the antimicrobial peptide beta-defensin 2 (DEFB2). METHODS: TLR and DEFB2 protein expression was investigated by immunohistochemistry on murine skin samples. RESULTS: Murine hair follicle expresses TLR2, TLR4 and TLR5; agonists of TLR2, TLR4 and TLR5 but not of TLR9 induced DEFB2 production in this compartment. The strongest DEFB2 expression was observed following TLR4 activation by lipopolysaccharide. CONCLUSIONS: Our data show that the hair follicle is equipped with TLR2, TLR4 and TLR5, and that these receptors are able to respond to microbial stimuli inducing the production of DEFB2 by epithelial cells. This immune response might be important in preserving the skin from microorganism infections.