DEVELOPMENT OF A NOVEL DEVICE FOR MEASUREMENT OF PEDAL FORCE IN CYCLING

A device was developed to be mounted between a cycling shoe and cleat with the ability to measure force perpendicular to the pedal. The device consists of a PolyPower force sensor placed in between two aluminium plates connected by three bolts. Furthermore, a mechanism allowing pulling forces to be measured is explained. The device was comparable to a golden standard when pushed upon, but did not provide valid measurements of pulling forces. In order to function as a valid and reliable power meter or a device capable of measuring pedal forces, the sensor´s recovery rate should be improved along with the pulling mechanism of the device while angular sensors could be added for assessment of pedal kinematics

The one-ski-method:effects of an alternative teaching approach on selected movement patterns in alpine skiing

Teaching methods in skiing have marginally developed within the last decades. An intervention comparing the conventional approach (SP) and the One-Ski-Method (OSM) is proposed in which the main body actions are first trained on one ski and successively transferred to two skis. The OSM teaches the main body actions towards a proper position on parallel skis. The snowplow gets avoided as it implies obstructive body actions. Two groups were trained using each method. Video footage from the first and the fifth day were evaluated by experts following selected criteria. OSM learners showed significantly larger improvements compared to SP. Results indicate a faster acquisition of key elements of alpine skiing and provide a foundation for further investigations of the OSM method

EFFECTS OF MEDIAL WEDGE INSOLES WHEN WALKING ON DIFFERENT SURFACES

Shoe inserts are often used to correct for foot misalignment or overloading during walking and running. To understand the interaction of medial wedge insoles and different surface hardness and geometry, we investigated plantar pressure and rearfoot movement. Twentyeight subjects with normal feet were tested when walking with and without insole on all combinations of hard and soft surface and level and upstairs walking. The main changes in load distribution and rearfoot movement were found between wearing insoles and not wearing them while differences between surfaces were small. In conclusion, surface hardness did not change the general effects of the insoles

Effects of medial wedge insoles when walking on different surfaces

Shoe inserts are often used to correct for foot misalignment or overloading during walking and running. To understand the interaction of medial wedge insoles and different surface hardness and geometry, we investigated plantar pressure and rearfoot movement. Twentyeight subjects with normal feet were tested when walking with and without insole on all combinations of hard and soft surface and level and upstairs walking. The main changes in load distribution and rearfoot movement were found between wearing insoles and not wearing them while differences between surfaces were small. In conclusion, surface hardness did not change the general effects of the insoles

SNOWBOARDER'S FRACTURE: CHANGING JOINT MECHANICS BY FOOT POSITION DURING A SIMULATED LANDING TASK

A high proportion of fractures to the lateral process of the talus (LPT) has been reported in snowboarding, which accounted for 34% of all ankle fractures (Kirkpatrick et al., 1998). A fracture to the LPT is an injury unique to snowboarders and is often misdiagnosed by physicians as an anterolateral ankle sprain. LPT fractures often involve the articular surface of the subtalar joint and it has been shown that misdiagnosis may lead to severe degeneration of the ankle joint and long term morbidity (Boon et aI., 1999). The mechanism of this injury has been studied intensively. LPT fractures are high impact injuries, landing after aerial manoeuvres is thought to be the major cause of LPT fractures (Boon et aI., 1999). In a cadaver study no fractures to the LPT were recorded under purely dorsalflexed conditions but in six of the eight specimens fractures occurred with the addition of 20° external rotation. An axial load of 2200 -8900 N was required to produce a fracture (LPT) in this position. It was proposed by Boon and colleagues tr.at the subsequent 'opening' of the ankle joint seen with heel inversion and external rotation of the talus results in the lateral process shifting upwards on the posterior articular process of the calcaneus. The purpose of this study was to simulate a snowboard landing in the laboratory with using an inverse dynamics approach to calculate effective joint loading for different binding alignments. It was hypothesised that the 'stance' chosen will affect loading and that an optimum foot alignment will help to minimise joint load

BIOMECHANICAL ANALYSIS OF THE HIGH JUMP AT THE SIXTH WCA IN ATHENS

Introduction: The main purposes of this study were 1. To determine the importance of initial conditions and take-off phase characteristics on jump performance. 2. To determine to what extent the initial conditions are effectively used by jumpers at the world class level. Methods: Data for this analysis were collected during the men’s high jump final competition at the 1997 Track and Field World Championships. A total of 26 successful jumps by 12 athletes were analyzed. The data was collected using 4 synchronized video cameras (50 Hz). Results and conclusions: On the basis of the total initial center of mass (CM) energy and the take-off characteristics, two relatively homogeneous groups could be identified. The take-off phase characteristics which are determined by the loss of CM energy during take-off and from the transformation of the approach energy to jump energy (transformation index) are very important for determining jump height. The initial energy of the CM determines the height an athlete can achieve. The actual jump height is strongly influenced by the take-off characteristics of the athlete. Both groups achieved the same jump height. Group 2 produced higher initial energy values. Group 1 demonstrated more efficient take-off characteristics. It was found that many athletes did not use their initial conditions optimally (Fig.1). The optimal energy decrease was calculated for the analyzed athletes as between 4 and 5 J/kg (Fig.1)