Sports mega-event legacies and adult physical activity: A systematic literature review and research agenda

Sports mega-events, such as the Olympic and Paralympic Games, have the potential to inspire increases in population physical activity, yet investigations concerning such legacy outcomes have been inconclusive. This may be due to research design limitations or inconsistent leveraging of potential hosting benefits by event organizers. This systematic review aims to identify current knowledge about the capacity of sports mega-events to inspire increases in physical activity participation among adult populations and develop a research agenda to guide future legacy evaluations. Peer-reviewed, English-language studies published on or after the year 2000 were considered. Six academic databases and grey literature sources were searched, and articles were assessed for methodological quality. Reporting followed PRISMA conventions for systematic reviews. Nine studies were selected after quality evaluation, including previous reviews, quantitative and qualitative research. Most studies found no evidence for long-term physical activity outcomes associated with hosting sports mega-events, although limitations and gaps were identified. These included lack of longitudinal or cohort studies, limited differentiation of subpopulations, use of non-validated instruments, and lack of triangulation for qualitative findings. Only one cohort study from Japan identified sustainable and significant physical activity increases resulting from a previous sports mega-event. Considering theory, the commonly cited Demonstration Effect was reportedly an unreliable framework, although the Festival Effect and Social Ecological Model appear more promising for anticipating and explaining legacy effects. With less than two years until the Tokyo 2020 Olympiad, it is appropriate to commence high-quality legacy research drawing on lessons learned from previous studies.     

The effect of muscle fatigue on instep kicking kinetics and kinematics in association football

The aim of this study was to examine the effect of leg muscle fatigue on the kinetics and kinematics of the instep football kick. Fatigue was induced by repeated, loaded knee extension (40% body weight) and flexion (50% body weight) motions on a weight-training machine until exhaustion. The kicking motions of seven male players were captured three-dimensionally at 500 Hz before and immediately after the fatigue protocol. The significantly slower ball velocity observed in the fatigue condition was due to both reduced lower leg swing speed and poorer ball contact. The reduced leg swing speed, represented by a slower toe linear velocity immediately before ball impact and slower peak lower leg angular velocity, was most likely due to a significantly reduced resultant joint moment and motion-dependent interactive moment during kicking. These results suggest that the specific muscle fatigue induced in the present study not only diminished the ability to generate force, but also disturbed the effective action of the interactive moment leading to poorer inter-segmental coordination during kicking. Moreover, fatigue obscured the eccentric action of the knee flexors immediately before ball impact. This might increase the susceptibility to injury.     

A novel comparison between standard and new testing procedures to assess shock absorbency of third generation artificial turfs

This study aims to re-examine to what extent the testing procedure of the Artificial Athlete Berlin (DIN18032) is a valid evaluation method to assess the shock absorbency of third generation artificial turf (3-g turf) and to establish a new testing procedure, which precisely reflects the acute load by human sports action. The DIN test was conducted for 3-g turfs with different infill component. The baseline of the load of acute human sports action was obtained from the ground reaction force underneath the standard type of 3-g turf sample during landing from a 55-cm height with minimal shock attenuation. For reproducing the force similar to such a hard landing, a testing rig was developed and the same 3-g turf samples were tested. The DIN test failed to distinguish most types of 3-g turf and was found to be inappropriate to evaluate the shock absorbency of the 3-g turf mainly due to bouncing actions of the test foot on measured samples. In contrast, the newly developed testing rig succeeded in illustrating the differences of shock attenuation properties among most types of 3-g turfs in a high loading condition. In terms of players’ safety, the necessity of high loading test using an alternative testing procedure was highlighted.     

Key motion characteristics of side-step movements in hip-hop dance and their effect on the evaluation by judges

In hip-hop dance, the elements of motion that discriminate the skill levels of dancers and that influence the evaluations by judges have not been clearly identified. This study set out to extract these motion characteristics from the side-step movements of hip-hop dancing. Eight expert and eight non-expert dancers performed side-step movements, which were recorded using a motion capture system. Nine experienced judges evaluated the dancers’ performances. Several parameters, including the range of motion (ROM) of the joint angles (neck, trunk, hip, knee, and face inclination) and phase delays between these angular motions were calculated. A quarter-cycle phase delay between the neck motion and other body parts, seen only in the expert dancers, is highlighted as an element that can distinguish dancers’ skill levels. This feature of the expert dancers resulted in a larger ROM during the face inclination than that for the non-expert dancers. In addition, the experts exhibited a bottom-to-top segmental sequence in the horizontal direction while the non-experts did not demonstrate any such sequential motion. Of these kinematic parameters, only the ROM of the face inclination was highly correlated to the judging score and is regarded as being the most appealing element of the side-step movement.