THE PHYSICAL DEMANDS OF GYMNASTIC-STYLE LANDINGS: UNDERSTANDING AND ALLEVIATING INHERENT PREDISPOSITION

T he research aims to develop insight into inherent mechanisms and regulatory strategies contributing to the physical demands of gymnastic-style landings. The use of a modelling approach to examine the interaction of: 1. a performer’s physical profile and self-selected landing strategy and 2: local mass distribution and mass tuning effects on impact loading is presented. Strategy adjustments accommodating inherent physical profiles were found to be essential in ensuring effective load attenuation but were acknowledged as potentially incompatible with current constraints in gymnastic scoring systems. Mass tuning partially alleviated the loading effects of inherent local mass profiles and was considered achievable without substantial alterations in the regulatory movement patterns

TREND ANALYSIS OF COMPLEX RELEASE AND RE-GRASP SKILLS ON THE HIGH BAR

The purpose of this study was to examine the influence of the Code of Points on the frequency and type of Kovacs performed on the high bar by elite gymnasts. Video recordings of high bar performances were collected from the 2000 Sydney Olympic Games and 2006 Aarhus World Championships. Development of the Kovacs skill within the Code of Points was informed by a trend analysis of the type and frequency of release skills at the two international competitions. Kovacs variations contributed to 50% of the release skills at the Olympic Games and 40% post qualification round at the World Championships. The high frequency of the Kovacs was attributed to the increase in associated difficulty ranking, potential to increase difficulty through shape and twisting option and durability within the Code of Points. Biomechanical analysis is required for further understanding of the completion and development of the Kovacs

PREPARATORY LONGSWINGS PRECEDING TKACHEVS ON UNEVEN BARS

The preparatory longswing on uneven bars is fundamental to the development of more complex skills in women’s gymnastics. The preceding longswing governs the release parameters that in turn determine the success of the straddle Tkachev (Arampatzis & Brüggemann, 2001). Of the many longswing variations currently in use in women’s gymnastics, this study aims to investigate differences in the biomechanics of three distinctive preparatory longswings used in performing the straddle Tkachev. The long term purpose is to increase understanding of these skills and potentially improve the effectiveness of coaching

JOINT KINEMATIC VARIABILITY IN THE AERIAL AND LANDING PHASES OF BACKWARD ROTATING DISMOUNTS FROM BEAM

This study aimed to develop insight into the joint kinematic variability in backward rotating dismounts from beam. Two-dimensional lower-body coordinate data were obtained for ten backward piked (BP) and tucked (BT) dismounts performed by four gymnasts (N = 80 trials). The within-gymnast coefficient of variation (CV%) in the joint angle profiles was lower in the aerial-landing phase transition than the remaining dismount element. The CV% was consistently larger in the initial joint configurations of the BP aerial and landing phases than the more basic BT skill. Initial ankle and hip joint landing configurations produced the largest CV% difference between skills (ankle: 9.4 %, hip: 9.4 %). The development of complex dismounts from beam requires a pre-programmed control strategy allowing joint kinematic modulations at the onset of aerial and landing phases

SURFACE MARKERS VERSUS CLUSTERS FOR DETERMINING LOWER LIMB JOINT KINEMATICS IN SPRINT RUNNING

The purpose of this study was to compare lower limb joint angle time histories using surface markers and segmental clusters. An athlete completed three single leg standing trials whilst moving the joints of the free leg from maximum flexion to maximum extension followed by seven maximal sprint runs. Trials were tracked by a three-dimensional CODA system. For standing trials, mean timing differences were greatest in maximum extension at the ankle and hip (0.01 s). Angle differences ranged from 2° (knee flexion) to 11° (ankle extension). Timing differences in sprinting were greatest in extension (hip 0.03 s) with joint angle differences in maximum flexion and extension 7 & 9° (ankle), 3 & 6° (knee) and 23 & 4° (hip) respectively. When comparing results from surface markers and clusters, a good level of agreement was found in the continuous knee flexion-extension profile, and the discrete timings for all joints

LANDING STRATEGY MODULATION IN BACKWARD ROTATING PIKED AND TUCKED SOMERSAULT DISMOUNTS FROM BEAM

The aim of this study was to develop understanding of the landing strategy modifications made when performing backward rotating piked (BP) and tucked (BT) dismounts from beam. Sagittal plane lower-body joint angular kinematic profiles were determined for four female gymnasts during the landing phase of BP and BT somersaulting dismounts. A common hip-biased landing strategy was employed by the four gymnasts in the dismounting skills. The more complex BP task was distinguished by the use of a more extended (3.7º) and flexed (5.0º) initial knee and hip joint configuration, respectively compared to the basic BT skill performed. Effective skill developments of backward rotating dismounts from beam may require modulation to the individual joint patterns defining the lower-body landing strategy

PREPARATORY LONGSWING TECHNIQUES FOR DISMOUNTS ON UNEVEN BARS

The purpose of this study was to quantify the biomechanical differences between two methods of performing the preparatory longswing preceding the double layout dismount. Video images of 6 female Olympic level gymnasts performing the double layout dismount (3 = straddle preparatory longswing, 3 = dished preparatory longswing) were recorded using two synchronised 50 Hz digital cameras. 3D DLT reconstructed coordinates were combined with inertia values to define discrete release variables including vertical and horizontal velocity of the mass centre, release angle and angular momentum about the gymnast’s mass centre. Joint angular kinematics at the hips and shoulders were contrasted with particular reference to the hip functional phase. Based on the reported release parameters the straddle longswing could be considered preferential

Local and systemic glucocorticoid metabolism in inflammatory arthritis

Background: Isolated, primary synovial fibroblasts generate active glucocorticoids through expression of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1). This enzyme produces cortisol from inactive cortisone (and prednisolone from prednisone). Objective: To determine how intact synovial tissue metabolises glucocorticoids and to identify the local and systemic consequences of this activity by examination of glucocorticoid metabolism in patients with rheumatoid arthritis (RA). Methods: Synovial tissue was taken from patients with RA during joint replacement surgery. Glucocorticoid metabolism in explants was assessed by thin-layer chromatography and specific enzyme inhibitors. RT-PCR and immunohistochemistry were used to determine expression and distribution of 11β-HSD enzymes. Systemic glucocorticoid metabolism was examined in patients with RA using gas chromatography/mass spectrometry. Results: Synovial tissue synthesised cortisol from cortisone, confirming functional 11β-HSD1 expression. In patients with RA, enzyme activity correlated with donor erythrocyte sedimentation rate (ESR). Synovial tissues could also convert cortisol back to cortisone. Inhibitor studies and immunohistochemistry suggested this was owing to 11β-HSD2 expression in synovial macrophages, whereas 11β-HSD1 expression occurred primarily in fibroblasts. Synovial fluids exhibited lower cortisone levels than matched serum samples, indicating net local steroid activation. Urinary analyses indicated high 11β-HSD1 activity in untreated patients with RA compared with controls and a significant correlation between total body 11β-HSD1 activity and ESR. Conclusions: Synovial tissue metabolises glucocorticoids, the predominant effect being glucocorticoid activation, and this increases with inflammation. Endogenous glucocorticoid production in the joint is likely to have an impact on local inflammation and bone integrity