Sprinters are always looking for an improvement in their time, from the gun going off until the finish. An effective start can lead to reaching top velocity sooner and a decreased finish time. New developments in starting blocks, more specifically the width of the starting block pedal, has allowed for variation in foot placement in the blocks. With the ability to change how wide an athlete can place their feet in the blocks, this study looked at trying to find an optimum spacing for college level sprinters. Thirteen Male College Sprinters (mean age = 23.08 years) participated in this study. Subjects self selected their longitudinal block spacing with 3 different lateral positions being tested. In position 1, the feet were placed as narrow as was allowed by the starting block, simulating the width of a traditional set of blocks. Position 2 was defined by the hip width of the individual, distance between right ASIS to left ASIS. Position 3 was the preferred foot width of the subject as determined by completing a vertical jump. Measurements of peak force on the blocks at the time of the start as well as time to 10 m were taken. Neither peak force nor time to 10 m were different between conditions (p = .887, p = .135). The normal condition, position 1 (20cm), was measured to be the narrowest width with position 3 (mean = 37.6cm) being the widest in all subjects. The use of wider pedals on starting blocks is a fairly new idea in track and field, and is something that many athletes have not had the chance to practice with. Since the older style of starting blocks only allowed for a narrow stance that is what track athletes have become accustomed to and could possibly explain why there was no significant difference seen between the 3 starting positions. More research should be done after a time of adaptation to the new starting blocks by the athletes.

Tillämpning av instrument vid utövande av explosiva idrottsgrenar, för att mäta en atlets kraftproduktion, kan användas vid analys för att fastställa hur bra en atlet presterar. Dessa typer av instrument finns på marknaden och är oftast tillämpade för sprintstarter och har funktionen att man kanfånga en atlet på film och koppla en händelse till det data som hämtats in via instrumentet. Nackdelenmed dessa system är att de antingen är väldigt dyra eller är i avsaknaden av att vara smidiga ochportabla då de oftast levereras med mycket kringutrustning.Syftet med detta examensarbete var att utveckla ett system bestående av en mobilapplikation, samtlogik till en mikrokontroll som registrerar den horisontella kraften vid sprintstarter från en analogkälla. Insamlade data beräknas och skickas sedan med hjälp av BLE-kommunikation till mobilapplikationen som presenterar kraftdata för användaren.Utöver detta var syftet även att få inhämtad kraftdata tidssynkroniserad mot en mobil enhet för attgöra det möjligt att utvärdera händelser mot externa källor som IMU och höghastighetsfilm.Resultatet av arbetet visar att det är möjligt att hämta samplade kraftdata från en mikrokontroll viaBLE-kommunikation. Det går även att presentera beräknade kraftdata visuellt för en slutanvändaremed en mobilapplikation och få händelserna tidssynkroniserade med hjälp av tidssynkroniseringsalgoritmer. Resultaten kan emellertid förbättras genom fortsatt utveckling av detta system. / The application of instruments in the practice of explosive sports, to measure an athlete's force production, can be used to determine how well an athlete performs. Present instruments on the marketare most often applied to sprint starts and function to capture an athlete on film, and link the eventto the data retrieved from the instrument. The disadvantages with present day systems are that theyare either too expensive or lack flexibility and portability as they are usually delivered with a lot ofperipherals.The purpose of this thesis was to develop a system of a mobile application and logical code to a microcontroller that register horizontal forces at sprint starts from an analog source. The collected datawas calculated and transmitted using BLE communication to the mobile application which presentsthe force data to the user.Moreover, the purpose was also to have the acquired force data time-synchronized with a mobile device to make it possible to evaluate events against external sources such as IMU and high-speed film.The result for the logic developed throughout this work demonstrate that it is possible to retrievesampled force data from a microcontroller via BLE communication. It was possible to present thecalculated force data visually to an end user with a mobile application and have the events time synchronized using time synchronization algorithms. However, the results can be further improved bydevelopment of the system.