Abstract

Important health and social benefits can be gained from participation in sports and exercise. Appropriate surface provision that aids sports participation, cannot be met by artificial surfaces alone — it requires natural turf surfaces to be utilised. Considerable improvement in the durability of natural turf surfaces and thus, a greater understanding of the human-natural sports surface interaction is required. Ground reaction force data have been used to help quantify how human participants respond to changes in natural turf properties during running and turning. A kinematic analysis would further this understanding. This EPSRC/UK funded study analyses kinematic response to variations in natural turf during running. Three different rootzone conditions (clay, sandy and rootzone) were constructed in portable plastic trays (0.60 m × 0.40 m × 0.08 m) and turfed with ryegrass. Trays were positioned in the laboratory on non-slip matting (6 mm thick) to form a continuous runway. Three-dimensional kinematic data (Vicon Peak, automatic, opto-electronic system 120 Hz) were collected for nine subjects wearing football boots (studded natural turf design) during running (3.83m.s−1). Group mean data for initial and peak ankle and knee angles and peak joint angular velocities were statistically compared using an analysis of variance with repeated measures (ANOVA R.M, p<0.05). Mechanical measures of surface hardness (Clegg Hammer) and shear were taken before and after subject testing and assessed using a paired t-test (p<0.05). Moisture content was also assessed. Kinematic data were found to be representative of typical running values presented in the literature. While mechanical measures revealed that natural turf conditions were not identical, changes in surface did not yield any significant kinematic differences. The consistent production of ankle and knee joint kinematics with changes in mechanical surface properties could suggest that humans prefer to maintain similar geometries when running on a variety of natural turf surfaces. Alternatively, the mechanical properties of the natural turf conditions may not have been sufficiently different to elicit changes in human response during running. Verf.-Referat