Question: How much of the ski length must be used for the front part?
About the article "Nordic combined", section "Ski jumping equipment".

Candidate passages:
 Bindings
 The binding must be mounted parallel to the run-direction.
The binding must be placed in such a way that a maximum 57% of the entire ski length is used as the front part.
 Boots
 High-backed, flexible yet firm boots with a low cut at the front.
They are designed to allow the skier to lean forward during flight.
 Connection cord
 Part of the binding; a cord that attaches the ski to the boot and prevents the wobbling of skis during flight.
 Ski jumping suit
 All portions of the ski jumping suit must be made of the same material and must show a certain air permeability.
The size of the suit must conform to the body shape in an upright position with certain tolerances.
 Jumping skis
 Jumping skis are manufactured especially for use on ski jumping hills.
Skis with a length of a maximum 146% of the total body height of the competitor may be used.
The curvature and shape of the skis is restricted by certain geometric features.
Ski nomenclature is straightforward.
Examining the ski from front to back along the direction of travel, the front of the ski (typically pointed or rounded) is the "tip", the middle is the "waist" and the rear (typically flat) is the "tail".
All skis have four basic measures that define their basic performance: length, width, sidecut and camber.
Skis also differ in more minor ways to address certain niche roles.
For instance, mogul skis are much softer to absorb shocks, and powder skis are much wider to provide more float. 
Outriggers are used to stop using a technique that involves bringing the skiers elbows from their raised position down to their hips while pushing the outriggers down.
When using the outrigger, skiers do not rotate their arms as this changes the location of the ski on the snow.
Skiers missing an arm use a technique that corrects lateral balance issues resulting from the missing arm.
A skier with an above the knee amputation may have a better ability to complete turns on the opposite of their amputation.
Skiers with hemiplegia have to be trained to use both sides of their body equally.
If they do not, they are likely to fall over when their skis cross in front of them.
One of the skiing techniques used by this class is called the three track method, and was developed as part of the American Training System.
For skiers with an amputation, one of the first skills learned using this technique is how to walk with the ski so the skier can learn how to flex the ankle, knee and hip.
This allows the skier to determine their centre of gravity.
The skier is then taught how hop turn in order to understand arm and leg coordination while on skis.
This technique is only used while stationary and is not a competition skill.
The skier next learns how to fall down and get back up again.
The next skill learned is climbing gentle terrain, followed by learning to go down a straight run and learning to stop.
After this, the skier learns how to get on and off a ski lift.
This is followed by learning how to traverse the fall line, which teaches the skier how to maintain the ski edge.
Other skills are then taught including the Uphill Christie, beginning turns, parallel turns, short swings and moguls.
In teaching skiers with cerebral palsy, instructors are encouraged to delay the introduction ski poles as skiers may overgrip them.
Use of a ski bra is also encouraged as it helps the skier learn correct knee and hip placement.
One method of learning to ski for competitors with cerebral palsy in this classification is the American Teaching System.
They first thing skiers learn is what their equipment is, and how to put it on and take it off.
Next, skiers learn about positioning their body in a standing position on flat terrain.
After this, the skier learns how to side step, and then how to fall down and get back up again.
The skier then learns how to do a straight run, and then is taught how to get on and off the chair lift.
This is followed by learning wedge turns and weight transfers, wedge turns, wide track parallel turns, how to use ski poles, and advanced parallel turns.
In the Biathlon, all Paralympic athletes shoot from a prone position. 
Skis design is based on complex scientific principles.
Ski construction must address a variety of factors.
A ski must be light enough to glide on top of the snow, but must also be strong enough to withstand the weight of the skier.
Skis are built with a curvature in the length of the ski known as camber, which provides stability in uneven terrain and varying snow consistency.
The ski must also have the ability to bend to optimize maneuverability and accommodate weight shifts during turning.
All skis are designed with the same primary structure- a wood, steel, or foam core which is then surrounded by more durable water-resistant materials.
Combinations of varying ski shapes, weights, lengths and widths are designed for different types of skiing, such as downhill or slalom skiing. 
An event very similar to the sport of biathlon except a recurve bow is used in place of a gun.
The athletes ski around a cross-country track and there are two stances in which the athlete must shoot the targets: kneeling and standing.
During competition the skis must not be removed at any time.
The athlete may unfasten the ski when shooting in the kneeling position but must keep the foot in contact with the ski.
The shooting distance is 18 meters and the targets in diameter.
In certain events, for every missed target, the athlete must ski one penalty loop.
The loop is 150 meters long.
In summer or regions with little snow, the European run archery is a mentionable alternative.