Aggressive inline skating
Aggressive inline skating (referred to by participants as rollerblading, blading, skating, street skating, rolling, roller freestyle or freestyle rolling) is a sub discipline of inline skating in the action sports canon. Aggressive inline skates are specially modified to accommodate grinds and jumps. Aggressive skating can take place on found street obstacles or at skate parks. History. In 1980, a group of ice hockey players in Minnesota were looking for a way to practice during the summer. Scott and Brennan Olson formed the company Rollerblade, Inc., to sell skates with four polyurethane wheels arranged in a straight line  on the bottom of a padded boot. In 1988, Rollerblade introduced the first aggressive inline skate, the Rollerblade Lightning TRS. Aggressive inline skating developed as an organized sport in the early 1990s. In 1994 the National Inline Skate Series, better known as NISS was launched as the first aggressive skating competition series. Promoters Rick Stark and Mark Billik sold Taco Bell on sponsoring the series for $150,000 and a six stop series was born. NISS, went strong for 5 years holding contests in Los Angeles, New York, Rome and Brazil. NISS was the first series to put aggressive inline  on television with an ESPN deal for the 1994 series and later moving the competition series to PRIME TICKET-Fox Sports. The Aggressive Skaters Association (ASA) was formed by a number of aggressive inline skaters in 1995 as a forum to develop rules governing competitions and equipment. The sport was included in the first ESPN X-Games in 1995 and included vertical ramp and street event competitions. It reached its height in popularity in the late 90s, with mainstream movies like Disney's Brink! and other films. The brand "Senate", run by Arlo Eisenberg and several other prominent skaters, enjoyed  mainstream popularity during the 1990s. Founded by company owners/skating legends Brian Shima, Jon Julio, and Kato Mateu and supported by all major skate companies, the World Rolling Series (WRS) links together the best skaters, event organizers, retailers and skate parks and aims to "create a tighter knit community, increase overall awareness and set a higher standard for aggressive rollerblading." The WRS circuit started in 2009 with 10 established professional contests in France, Netherlands, England, Spain, Argentina, Australia and the United States. In 2012, WRS included 100+ amateurs and professional events in over 20 countries. Aggressive inline skating was  removed from the ESPN X-Games in 2005 although it is still included in the Asian X Games, LG Action Sports Competitions, Montpellier Fise, and many other large competitions, some associated with WRS, some not. Due to the 2022 Russian invasion of Ukraine, World Skate banned Russian and Belarusian athletes and officials from its competitions, and will not stage any events in Russia or Belarus in 2022. Hardware. Aggressive skates are identifiable from recreational or speed skates by a prominent gap in between the second and third wheels (The H-Block) which allows for grinds perpendicular to the direction of  the wheels. A hard plastic surface on the sole of the boot known as a "Sole plate" or "Soul Plate" allows grinds parallel to the direction of the wheels. From these grind surfaces comes a lexicon of well known grind stances, though sliding can occur on any surface of the boot or wheels. Aggressive skates typically have much smaller wheels than a traditional inline skates. The small size allows for more freedom when grinding as there is less risk of catching on obstacles. Additionally these small wheels feature a flat profile to accommodate the impact from jumping tall heights. In  recent years aggressive skates have begun to adopt larger frames and wheels, in what is seen as a bridging of the various inline disciplines. Frames. The frame is the chassis that holds the wheels in place. The common feature of aggressive skate frames is the space between the second and third wheels known as an H-Block. H-Blocks are designed as an intended grind space, with varying sizes and designs to accommodate different styles of skating. Like all skate parts, frames were initially an integrated part of the boot and were not interchangeable. As aggressive skate designs developed, replaceable  parts became standard. In the late 1990s, the Universal Frame System (UFS) was introduced. The standard allowed any UFS frame to fit any UFS compatible boot, allowing for greater setup customization. Today, all major aggressive frame and skate manufacturers support UFS. Wheels, Anti-Rocker wheels, and Freestyle frame setups. Modern polyurethane skate wheels have been dependent on advancements in the polymer industry. The balance between hardness and grip is the key to an optimum skate wheel. Aggressive skate wheels are usually between 54 and 72mm, while anti-rocker wheels are between 40 and 47mm. Anti-rocker wheels are  small, dense wheels designed for grinding rather than rolling. Their small size allows for easier access to the H-block of the frame when installed in the 2nd and 3rd wheel positions. Anti-rocker wheels are typically made of high durometer urethane or plastic, allowing them to slide while grinding. Despite not rolling on the ground, anti-rockers are capable of rotating should they make contact with hard surfaces; which many find superior to having no wheels in the center positions. "Anti-rocker" refers to the inverse size of the 2nd and 3rd wheels compared to the 1st and 4th ; whereas a "rockered" wheel setup consists of smaller wheels in the 1st and 4th positions to simulate the curvature of an ice-skate blade. Riding without center wheels is known as a "Freestyle" setup, and offers the maximum potential space to grind. Anti-Rocker and freestyle setups are generally less maneuverable than flat setups due to a lack of central pivot points under the foot; but make a trade off for increased room to grind. Tricks. Aggressive skating tricks have been popularized in the 90's. Like in skateboarding they can be divided into manuals, grinds, aerials (flips, grabs) and  stalls. Grinds. Grinds can be divided into soul grinds, where one skate is grinding on the soul plate, and groove grinds / slides, where both skates slide on the H-Block / Backslide plate. Aerials. Aerial tricks in Aggressive skating are based on their counterparts in skateboarding and consist of flips and grabs. Media. Video. Skate videos began in 1993 with the release of "Dare to Air", a Video Groove series and "Air Attack". K2, Bauer and Rollerblade were early proponents of the sport and released their own videos. Senate, arguably the first inline-only company, released a number of influential films  during the 1990s. Videogroove, Mindgame, Razors, KFC, and Valo released a number of notable films during the early 2000s. During this period the genre transitioned from VHS to DVD like much of the rest of the entertainment industry. They have similarly transitioned to the digital format since the 2010s. Skate videos, like their skateboarding and BMX counterparts, feature skaters both professional and amateur, in "edits," segments of skating usually accompanied by one or more songs. Music is often used without permission. Alternatively, original music is sometimes created specifically for the film. A 2006 documentary, "Barely Dead", gives an overview of  skating, focusing on its popularity and decline. Competitions. The largest aggressive inline skating focused competitions are: