Editing Inline skates (section)

== Anatomy and function ==

[[File:Inline skate parts-Boot-Frame-Wheels-PS Tau urban boot-Nexus Rocker 235mm frame-PS Spinner 90mm wheels-Right skate-IMG 3786-IMG 5890-FRD.png|thumb|right|200px|Boot, frame, wheels, bearings, axles and tool]]

All modern inline skates share a common basic blueprint. A skate comprises a '''boot,''' worn on the foot. To the bottom of the boot is attached a '''frame''', the most rigid part of the skate. The frame holds a number of '''wheels''' in place with wheel '''axles'''. In between a wheel and an axle are two '''bearings'''. Bearings allow a wheel to rotate freely around its axle. Finally, a rubber '''brake''' typically attaches to the frame of the right boot, on recreational skates.<ref name="fried-cassorla-inline-ultimate-guide-1995"/>{{rp|17–27}}<ref name="powell-svensson-inline-skating"/>{{rp|14–39}}<ref name="miller-get-rolling-2003"/>{{rp|41–51}}

For many skaters, the frame is never removed or replaced. But wheels are consumables, as they wear down with use, and require periodic mounting rotations and even replacements.<ref name="rollerblades-dryland-training-1985"/>{{rp|81–86}} Inline skates usually come with a skate tool for wheel, bearing and frame maintenance. The tool will have a hex wrench or a Torx wrench for removing wheel axles from a frame, and wherever applicable, for removing bearings from a wheel, and for removing a frame from a boot.<ref name="vegter-everthing-about-skate-tools">{{cite web
|first1=Ivo
|last1=Vegter
|title=Everything About Skate Tools
|others=See video transcript on all types of skate tools with hex, Torx and other wrench tips for removing wheel, axels, frames and bearings.
|url=https://www.youtube.com/watch?v=genZ_KT-nHY
|website=thisissoul.com
|publisher=This is Soul
|language=en
|format=video
|date=2022-03-13
}}</ref><ref name="fried-cassorla-inline-ultimate-guide-1995"/>{{rp|39–45}}<ref name="powell-svensson-inline-skating"/>{{rp|39–51}}

{{multiple image
 | direction = horizontal
 | total_width = 340
 | image1 = Powerslide One Zoom-inline skates-IMG 5814-single skate-FRD.png
 | image2 = Inline-Skate-Soft-boot-K2-Cadence-SL.png
 | caption1 = Hard boot
 | caption2 = Soft boot
}}
[[File:Inline Skate-Hybrid boot with carbon shell-Powerslide Tau on Endless 90 frame with 3x110mm wheels-IMG 4271-FRD.png|thumb|right|180px|Hybrid boot]]

In the 1980s and 1990s, all inline skates had '''hard boots''', borrowed from ski boot designs. A removable liner in a hard boot provides a snug yet comfortable fit between a skater's foot and the hard shell. Around 1996, K2 introduced '''soft boots''' with an exoskeleton. These provide the most comfortable fit, at the expense of reduced rigidity. In the 2010s, '''hybrid (soft) boots''' with an endoskeleton were introduced to the high-end market. A hybrid boot has an integrated, non-removable liner. This is glued to a rigid endoskeleton shell integrated with the sole, providing direct power transfer from the foot to the wheels.<ref name="gutman-catching-air-2004"/>{{rp|142}}<ref name="vegter-names-in-inline-skating"/><ref name="powerslide-hard-soft-hybrid-boots"/>

All three types are able to secure a foot in them without slack, with proper closure systems. Soft boots are often laced, and hard shells are usually secured with buckles. Velcro straps are also common in all types of boots. Well-designed boots provide proper heel support and ankle support to a skater.<ref name="powell-svensson-inline-skating"/>{{rp|14–39}}<ref name="miller-get-rolling-2003"/>{{rp|47–52}}<ref name="gutman-catching-air-2004"/>{{rp|142}}

The length of a frame positively affects stability and negatively affects turning agility. Longer frames accommodate more wheels, and taller frames larger wheels; both positively affect top skating speed. Modern inline skates are equipped with polyurethane wheels. Softer wheels provide a better grip on smooth indoor surfaces, while harder wheels wear down less on rough outdoor surfaces. Beginners skate with all wheels touching the ground, for enhanced stability, known as a "flat" wheel setup. Advanced skaters may choose to configure wheels in a "rockered" setup for enhanced maneuverability. The weight of a skate is an important consideration for some disciplines. Lighter boots, frames, and wheels are preferred. However, weight reduction is only achieved with escalating costs and diminishing returns.<ref name="powell-svensson-inline-skating"/>{{rp|14–39}}<ref name="joyner-inline-hockey-1995"/>{{rp|19–33}}

=== Heel support ===

Heel support refers to the ability of a boot to keep a skater's heel comfortably seated and firmly locked down in the heel pocket of the boot, even during aggressive maneuvering.

[[File:Heel support in an inline skate-illustration-IMG 4591-FRD.png|thumb|right|340px|A contoured heel pocket and a proper closure system work together to lock in the heel]]

A heel pocket is formed by the shell, inner liner and sole of a boot. A properly-designed boot has a heel pocket that hugs the heel, with an anatomical contour. A proper closure system causes the "facing" (where eyelet tabs are) to push the instep against the heel pocket, preventing the foot from shifting or lifting during maneuvers. As a result, the heel remains in contact with the footbed at all times.<ref name="powell-svensson-inline-skating"/>{{rp|15–18}}

Proper '''heel lock''' serves as a stable foundation for the entire foot. It allows a skater to adopt an athletic stance for skating by flexing the lower leg forward, without raising the heel. A snug fit means reduced movement of the foot within the skate, and thus reduced opportunity for friction to cause blisters. At the same time, the whole skate becomes transfixed to the foot as an extension of it, allowing efficient strides with a faithful transfer of power from the foot to the ground.<ref name="feineman-wheel-excitement"/>{{rp|35–36,79–80}}

=== Ankle support ===

[[File:Ankle support in an inline skate-illustration-IMG 4591-FRD.png|thumb|right|320px|Rigid carbon-fiber quarter panels of this hockey boot prevents sideway wobbles of the foot while allowing the shin to flex forward]]

[[File:Ankle support in an inline skate-Dorsiflexion in a hokey skate-IMG 1334-IMG 1333-FRD.png|thumb|right|x180px|Dorsiflexion (left) vs leg extended straight (right)]]

Ankle support refers to the ability of a boot to prevent sideways movement of a skater's ankle and lower leg, while allowing the shin to flex forward into an athletic stance. In some skates, such as recreational and aggressive skates, this is achieved via a hinged cuff. In other skates, such as hockey skates, this is enabled by rigid, and anatomically-shaped quarter panels that lock both ankle bones in place, from two sides, leaving the shin to freely pivot forward.<ref name="powell-svensson-inline-skating"/>{{rp|5,15–18}}<ref name="vegter-hybrid-hard-boot-soft-boot"/>

Proper ankle support allows a skater to keep a skate upright as a straight extension of their entire leg, when observed from the front. Without rigid support on both sides of the ankle, the foot may wobble within the boot, causing the skate to tilt inward or outward. This creates pronation, making it harder for a skater to glide on a single skate at best, and resulting in sprains and other injuries at worst.<ref name="xinhaidude-how-to-inline-skate"/>

A properly-designed boot does not hinder the mobility of the ankle joint, allowing a skater to pivot the lower leg (the shin) forward, adopting a squatting (athletic) stance. This '''forward flex''' (or '''forward leaning''') is known as '''dorsiflexion''' of the foot. It places the center of body mass atop the ball of the foot, a balancing skill crucial to most skating moves. Without such a squatting stance, the leg and the skate form a 90° angle, placing the entire body weight of a skater on the rear wheel of the skate. This is dangerous for a beginner because a small backward shift of the upper body will cause a skater to pivot their entire body on the rear wheel, and thus fall uncontrollably backward.<ref name="powell-svensson-inline-skating"/>{{rp|67–77}}<ref name="miller-get-rolling-2003"/>{{rp|57–59}}