Enrique Alcántara

Properties of shoe insert materials related to shock wave transmission during gait.

The influence of the mechanical characteristics of certain insole materials in the generation and transmission of heel strike impacts while walking was studied. Three insole materials were selected according to their mechanical characteristics under heel strike impacts. The selection of materials has made it possible to distinguish the effect of rigidity and loss tangent in the transmission of heel strike impacts. A lower rigidity and a high loss tangent have been shown to reduce the transmission of impacts to the tibia. A low rigidity was seen to significantly increase the transmission of impacts from tibia to forehead.

The MORFO3D foot database

A foot database comprising 3D foot shapes and footwear fitting reports of more than 300 participants is presented. It was primarily acquired to study footwear fitting, though it can also be used to analyse anatomical features of the foot. In fact, we present a technique for automatic detection of several foot anatomical landmarks, together with some empirical results.

A methodology of selecting a suitable garment for sports use

Purpose – Choosing the adequate garment for sports practice in adverse weather conditions, either cold or hot, is an aspect of great influence on activity performance. The purpose of this paper is to describe how the Institute of Biomechanics of Valencia has developed a methodology which allows assessing the fit of the garment to the real situation of use by evaluating its influence in the thermoregulatory response of the human body.Design/methodology/approach – Under controlled environmental conditions and at fixed activity levels, two shirts are tested in the laboratory. Eight subjects performed a test which consisted of six phases of different activity level in two conditions (25°C/50 percent RH and 10°C/60 percent RH). Throughout the test, physiological parameters of the thermal response as well as work load indicators are registered. Skin temperature at three different locations (chest, arm, and thigh), microclimate variables in some areas of subject‐garment interface (in armpit and upper back) and h...

Development Of A New Technique To Evaluate Abrasivieness Artificial Turf (P168)

Several studies can be found that compare the risk of injury on artificial turf and natural grass, mainly regarding the risk of injury in ankle and knee. A main problem of artificial turf is, however, related to the injuries due to sliding and it has not been studied in depth.

Applications of Kansei Engineering to Personalization

This chapter proposes two practical ways to include user preferences in a personalization system aimed at psychological perception and based on a Kansei system. In many mass customization systems the consumer as an inexperienced designer can get lost and will become frustrated about the huge amount of offered possibilities. We will discuss how Kansei engineering can be used to guide customers in order to quickly find the desired design according to their preferences. Secondly, the number of possible design options and combinations in a modular personalization system can be higher than stocking, logistic and manufacturing capabilities. Focusing production variability on features affecting most users’ preferences and purchase decisions may reduce this amount of design options. We will use case studies form the office furniture and footwear industry to support these ideas.

Artificial Turf Development as Surface for Golf Practice (P143)

Demand for new golf courses is rising due to the increasing number of golfers, especially in coastal areas of South Europe with high sunshine and temperatures, but with very restrictive factors as water shortage. This factor has produced a growing interest in the introduction of artificial grass for golf courses. The aim of this study was the development of artificial turf for golf. At present, the behaviour of natural grass is considered as the reference for the development of artificial grass as a surface for golf courses. However, there is little information about its mechanical behaviour. The first step of this study was to generate a reference model of natural turf behaviour. Two discussion groups were conducted to identify and prioritize the requirements of the main zones of a golf course. After that, testing procedures and devices were developed for the study of the above-mentioned requirements. The tests carried out were rotational resistance, divot hole strength, ball roll, distance after bounce and angled ball rebound. The testing results were used to develop the proposed reference model in terms of reference values for the measured properties. After that, artificial turf samples (tee (14 samples), fairway (18), green (8)) were build using different carpets, sand size infill and different shock pads. The same tests were carried out on these samples. ANOVA statistical treatment was carried out on the obtained results. From the ANOVA, those artificial turf samples with the most similar behaviour to natural turf’s behaviour were determined for each golf course area.

Measurement of Hand Palm Pressures in “La Pelota Vasca” Game

“Pelota Vasca” is a traditional sport coming from the Pais Vasco with a long history and different modalities. In one of them the ball is hit with the hand against a wall placed in front of the players. A high incidence of hand injuries is found in this sport which has been related to high impact loads and to not adequate protection. Nevertheless, there is not knowledge about biomechanical parameters as impact forces in the hand, hand pressure distribution and others that would be required for an adequate protection design. The purpose of this study was to measure the hand impacts magnitude and distribution when playing “Pelota Vasca”. Nine high level players took part in the study. A pneumatic canon was used to throw the ball at 80 km/h speed, that was controlled by two photocell gates. The ball rebounded first against the wall and then on the floor before to be hit by the player. The players hand was equipped with an instrumented glove especially developed for this study. It included 8 piezoelectric sensors distributed according to hand functional anatomy and considering the hitting areas of the hand. Specific software was developed to compute peak pressure at each sensor which was stored for further statistical analysis. The maximum recorded pressure ranged between 4020 kPa and 4378 kPa, at the 2nd and 3rd metacarpal heads respectively. Those values are very high, similar to plantar pressures recorder for speed athletes during maximal speed running, what suggest that the current protection should be improved to reduce pressures.

Analysis of the Relationship Between Mechanical Properties and Players’ Perception of the Balls in a Spanish Traditional Sport: “La Pilota Valenciana”

“La Pilota Valenciana” is a traditional sport native from the Region of Valencia (Spain). In a modality of it, two teams hit a ball with the hand to pass it above a net. The balls are made by highly skilled craftsmen and there are neither technical criteria for quality control nor design criteria for developing new products. At present, the decision about the suitability of a ball for the game is made on the base of manufacturers and players subjective opinion. This paper presents the research done to establish which mechanical properties of balls correlate with players’ perception to generate design and evaluation criteria. The results showed several significant correlations between some mechanical properties as the Coefficient of restitution and users opinion. For example, hardness correlated positively with the perception of injury risk. The results of this study establish the necessary knowledge and methodology to advance in the quality control and design of balls for the “pilota valenciana”, which is very necessary to ensure the future of this traditional game.