In mountaineering

Mountaineering

Mountaineering or mountain climbing is the sport, hobby or profession of hiking, skiing, and climbing mountains. While mountaineering began as attempts to reach the highest point of unclimbed mountains it has branched into specialisations that address different aspects of the mountain and consists...

 and hiking

Hiking

Hiking is an outdoor activity which consists of walking in natural environments, often in mountainous or other scenic terrain. People often hike on hiking trails. It is such a popular activity that there are numerous hiking organizations worldwide. The health benefits of different types of hiking...

, the rest step is a human

Human

Humans are the only living species in the Homo genus...

 walking

Walking

Walking is one of the main gaits of locomotion among legged animals, and is typically slower than running and other gaits. Walking is defined by an 'inverted pendulum' gait in which the body vaults over the stiff limb or limbs with each step...

 gait

Gait

Gait is the pattern of movement of the limbs of animals, including humans, during locomotion over a solid substrate. Most animals use a variety of gaits, selecting gait based on speed, terrain, the need to maneuver, and energetic efficiency...

 used in ascending steep slope

Slope

In mathematics, the slope or gradient of a line describes its steepness, incline, or grade. A higher slope value indicates a steeper incline....

s. Its essential characteristic is a pause of motion with the rear leg

Human leg

The human leg is the entire lower extremity or limb of the human body, including the foot, thigh and even the hip or gluteal region; however, the precise definition in human anatomy refers only to the section of the lower limb extending from the knee to the ankle.Legs are used for standing,...

 vertical and fully extended, while the front leg is relaxed except as needed to adjust the balancing

Balance (ability)

In biomechanics, balance is an ability to maintain the center of gravity of a body within the base of support with minimal postural sway. When exercising the ability to balance, one is said to be balancing....

 of the climber's body and burden on the rear leg.

The goal includes "locking" the knee, in order to rest the weight on the skeleton

Human skeleton

The human skeleton consists of both fused and individual bones supported and supplemented by ligaments, tendons, muscles and cartilage. It serves as a scaffold which supports organs, anchors muscles, and protects organs such as the brain, lungs and heart....

 (and relieve the leg muscle

Muscle

Muscle is a contractile tissue of animals and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to...

s of exertion as much as possible).

Climbers may often execute the rest step spontaneously, if waiting either for the next step of a climber who is a step or two ahead, or for the energy

Energy

In physics, energy is an indirectly observed quantity. It is often understood as the ability a physical system has to do work on other physical systems...

 to continue. Nevertheless, conscious practice

Practice (learning method)

Practice is the act of rehearsing a behavior over and over, or engaging in an activity again and again, for the purpose of improving or mastering it, as in the phrase "practice makes perfect". Sports teams practice to prepare for actual games. Playing a musical instrument well takes a lot of...

 at delaying the next step (requiring inhibition of a walking reflex

Reflex

A reflex action, also known as a reflex, is an involuntary and nearly instantaneous movement in response to a stimulus. A true reflex is a behavior which is mediated via the reflex arc; this does not apply to casual uses of the term 'reflex'.-See also:...

) is widely deemed worthwhile. That skill enables ascent at the maximum steady pace, on slopes where quadriceps endurance, or the rate of consumption of either energy or oxygen is the factor limiting the rate of advance, whether some climbers or all in the party are operating at that limit.

The rest step is especially emphasized in steep ascents on firm snow

Snow

Snow is a form of precipitation within the Earth's atmosphere in the form of crystalline water ice, consisting of a multitude of snowflakes that fall from clouds. Since snow is composed of small ice particles, it is a granular material. It has an open and therefore soft structure, unless packed by...

, often including the additional feature of keeping the moving foot close to the snow surface and scraping it against the snow as it comes to rest, especially to preserve and reinforce the improved footing available in the footprint left by the immediately previous climber.