There are many different types of footwear available for runners in today's market. Many of these shoes claim to improve a runner's efficiency by altering their stride mechanics. Minimalist footwear claims to aid runners in running more on their forefeet whereas more traditional footwear provides more cushioning specifically for a heel-first landing. The purpose of this research was to determine if runners who were accustomed to running in traditional footwear would acutely alter their running biomechanics when they ran barefoot or in various types of minimalist footwear. Twelve subjects, who were accustomed to running in traditional 12 mm heel/toe differential footwear, ran in five footwear conditions on a treadmill at a controlled pace for 2 minutes after warming up in each condition for 5 minutes. While running in 12 mm heel/toe differential footwear compared to barefoot, subjects ran with a significantly longer ground time, a slower stride rate and greater vertical oscillation. There were not any significant differences in kinematic and kinetic variables when running in the shod conditions despite the varying heel/toe differentials. Foot strike angle did not change under any of the conditions either. Running barefoot proved to be different than running in footwear in that stride rate increased, ground time decreased and vertical oscillation decreased. There were not any significant acute differences between any of the footwear conditions despite having different heel/toe differentials in subjects accustomed to wearing traditional heel-drop footwear. Wearing minimalist or cushioned minimal footwear appears to not be an effective means of changing running mechanics acutely but may need repeated bouts to alter running mechanics.

The main problems concerning birth of running injuries is their unclear ethiopathogenesis and high frequency. Injuries are often lined with forces affected on tread-down which have to be defused by running shoes. There are also opinions that currently used footwear can cause injuries on the contrary. This work explores impact of particular types of running shoes for influencing of stability. Methods: There are compared two groups of runners: minimalists and classic runners. Their stability is examined with help of posturography in three versions: barefoot, classic and minimalistic footwear. Thereafter there is analyzed relation among stability, used footwear, training usage and frequency of injuries. Results: Minimalists and classic runners have the same stability while they are barefoot. Usage of footwear does not cause significant deterioration of stability in any of groups. Nevertheless most of runners subjectively evaluate the variant of testing barefoot as the simplest. There is more frequent occurence of flat foot among classic runners in comparison with minimalists. Flat foot increases risk of formation injuries, on the contrary, regular compensation motion activity decreases this risk.

Bakgrund: Löpning är en populär motionsform i Sverige idag, dock är det vanligt med överbelastningsskador bland löpare och nästan 80% skadar sig på något vis varje år. Diskussion har uppstått bland löpare och forskare kring om barfotalöpning kan förändra biomekaniken och därmed ändra belastningen och minska risken för skador, samt om barfotalöpning kan leda till en förbättrad löpekonomi och påverka löparens prestationer. Syfte: Att undersöka vilken effekt barfotalöpning (inkl. minimalistskor) har på biomekanik mätt med ground reaction force (GRF) och löpekonomi mätt med syreupptagning jämfört med löpning med konventionella skor.  Metod: Systematisk narrativ litteraturöversikt. Litteratursökningen genomfördes i databaserna Pubmed och Cochrane. Studier som var randomiserade kontrollerade studier (RCT) alternativt cross-over studier inkluderades. Kvalitetsgranskning av studierna genomfördes med PEDro och tillförlitligheten av resultatet bedömdes med GRADEstud. Resultat: Åtta artiklar inkluderades, tre om biomekanik och fem om löpekonomi. Inga samstämmiga resultat sågs gällande barfotalöpningens effekter på GRF, en studie påvisade en signifikant minskning medan två studier visade på en signifikant ökning av GRF. Positiva tendenser sågs i studierna om löpekonomi, varav två påvisade signifikanta förbättringar. Kvaliteten på artiklarna bedömdes som måttlig och tillförlitligheten till resultaten bedömdes vara mycket låg.  Konklusion: Barfotalöpning påvisar vissa positiva effekter på löpekonomi medan effekterna på GRF är motstridiga. Tillförlitligheten av evidensen bedömdes vara mycket låg. Det behövs fler högkvalitativa studier som undersöker de långvariga och akuta effekterna av barfotalöpning på löpekonomi och biomekanik för att kunna dra slutsatser och implementera kunskapen bland fysioterapeuter som arbetar med löparskador. / Background: Running is a popular activity in Sweden today. However, injuries are common and almost 80% of runners get injured each year. Discussions about whether barefoot running could alter the biomechanics and decrease the risk of injury, and improve the running economy and increase a runner's performance, has risen amongst runners and researchers. Purpose: To examine the effects of barefoot running (minimalist footwear) on biomechanics measured with ground reaction force (GRF) and running economy measured with oxygen consumption compared to shod running.  Method: A systematic review. Articles were found using the Pubmed and Chochrane database. Randomised controlled trials (RCT) or Cross-over studies were included. Assessment of study quality was measured with the PEDro-scale and the reliability of the result assessed with GRADEstud. Result: Eight articles were included, three about biomechanics and five about running economy. Inconclusive results were found on the effects of barefoot running on GRF, one study showed a significant reduction in GRF and the other two showed increase in GRF. Positive tendencies were found concerning running economy, two studies showed a significant increase. The quality of the studies were moderate and the reliability of the result were very low. Conclusion: Barefoot running showed positive findings on running economy, while the effects on GRF were inconclusive. The evidence was considered very low. There is a need for more high-quality studies examining the long-lasting and acute effects of barefoot running on running economy and biomechanics to be able to draw conclusions and implement the knowledge in clinical physiotherapy.