Jumping or leaping is a form of locomotion or movement in which an
organism
In biology, an organism () is any life, living system that functions as an individual entity. All organisms are composed of cells (cell theory). Organisms are classified by taxonomy (biology), taxonomy into groups such as Multicellular o ...
or non-living (e.g.,
robotic) mechanical system propels itself through the air along a ballistic trajectory. Jumping can be distinguished from running, galloping and other
gaits where the entire body is temporarily airborne, by the relatively long duration of the aerial phase and high angle of initial launch.
Some animals, such as the
kangaroo
Kangaroos are four marsupials from the family Macropodidae (macropods, meaning "large foot"). In common use the term is used to describe the largest species from this family, the red kangaroo, as well as the antilopine kangaroo, eastern ...
, employ jumping (commonly called ''hopping'' in this instance) as their primary form of
locomotion, while others, such as frogs, use it only as a means to escape predators. Jumping is also a key feature of various activities and sports, including the
long jump
The long jump is a track and field event in which athletes combine speed, strength and agility in an attempt to leap as far as possible from a takeoff point. Along with the triple jump, the two events that measure jumping for distance as a gr ...
,
high jump and
show jumping.
Physics
All jumping involves the application of force against a substrate, which in turn generates a reactive force that propels the jumper away from the substrate. Any solid or liquid capable of producing an opposing force can serve as a substrate, including ground or water. Examples of the latter include dolphins performing traveling jumps, and
Indian skitter frogs executing standing jumps from water.
Jumping organisms are rarely subject to significant
aerodynamic force
In fluid mechanics, an aerodynamic force is a force exerted on a body by the air (or other gas) in which the body is immersed, and is due to the relative motion between the body and the gas.
Force
There are two causes of aerodynamic force:
...
s and, as a result, their jumps are governed by the basic physical laws of
ballistic trajectories
Ballistics is the field of mechanics concerned with the launching, flight behaviour and impact effects of projectiles, especially ranged weapon munitions such as bullets, unguided bombs, rockets or the like; the science or art of designing and a ...
. Consequently, while a bird may jump into the air to initiate
flight
Flight or flying is the process by which an object moves through a space without contacting any planetary surface, either within an atmosphere (i.e. air flight or aviation) or through the vacuum of outer space (i.e. spaceflight). This can b ...
, no movement it performs once airborne is considered jumping, as the initial jump conditions no longer dictate its flight path.
Following the moment of launch (i.e., initial loss of contact with the substrate), a jumper will traverse a parabolic path. The launch angle and initial launch velocity determine the travel distance, duration, and height of the jump. The maximum possible horizontal travel distance occurs at a launch angle of 45 degrees, but any launch angle between 35 and 55 degrees will result in ninety percent of the maximum possible distance.
Muscles (or other
actuator
An actuator is a component of a machine that is responsible for moving and controlling a mechanism or system, for example by opening a valve. In simple terms, it is a "mover".
An actuator requires a control device (controlled by control signal) a ...
s in non-living systems) do physical work, adding
kinetic energy
In physics, the kinetic energy of an object is the energy that it possesses due to its motion.
It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its a ...
to the jumper's body over the course of a jump's propulsive phase. This results in a
kinetic energy
In physics, the kinetic energy of an object is the energy that it possesses due to its motion.
It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its a ...
at launch that is proportional to the square of the jumper's speed. The more work the muscles do, the greater the launch velocity and thus the greater the acceleration and the shorter the time interval of the jump's propulsive phase.
Mechanical
power (work per unit time) and the distance over which that power is applied (e.g., leg length) are the key determinants of jump distance and height. As a result, many jumping animals have long legs and muscles that are optimized for maximal power according to the
force-velocity relationship of muscles. The maximum power output of muscles is limited, however. To circumvent this limitation, many jumping species slowly pre-stretch elastic elements, such as
tendon
A tendon or sinew is a tough, high-tensile-strength band of dense fibrous connective tissue that connects muscle to bone. It is able to transmit the mechanical forces of muscle contraction to the skeletal system without sacrificing its ability ...
s or
apodemes, to store work as strain energy. Such elastic elements can release energy at a much higher rate (higher power) than equivalent muscle mass, thus increasing launch energy to levels beyond what muscle alone is capable of.
A jumper may be either stationary or moving when initiating a jump. In a jump from stationary (i.e., a ''standing jump''), all of the work required to accelerate the body through launch is done in a single movement. In a ''moving jump'' or ''running jump'', the jumper introduces additional vertical velocity at launch while conserving as much horizontal momentum as possible. Unlike stationary jumps, in which the jumper's kinetic energy at launch is solely due to the jump movement, moving jumps have a higher energy that results from the inclusion of the horizontal velocity preceding the jump. Consequently, jumpers are able to jump greater distances when starting from a run.
Anatomy
Animals use a wide variety of anatomical adaptations for jumping. These adaptations are exclusively concerned with the launch, as any post-launch method of extending range or controlling the jump must use aerodynamic forces, and thus is considered
gliding
Gliding is a recreational activity and competitive air sport in which pilots fly unpowered aircraft known as gliders or sailplanes using naturally occurring currents of rising air in the atmosphere to remain airborne. The word ''soaring'' is ...
or
parachuting
Parachuting, including also skydiving, is a method of transiting from a high point in the atmosphere to the surface of Earth with the aid of gravity, involving the control of speed during the descent using a parachute or parachutes.
Fo ...
.
Aquatic species rarely display any particular specializations for jumping. Those that are good jumpers usually are primarily adapted for speed, and execute moving jumps by simply swimming to the surface at a high velocity. A few primarily aquatic species that can jump while on land, such as
mud skippers, do so via a flick of the tail.
Limb morphology
In terrestrial animals, the primary propulsive structure is the legs, though a few species use their tails. Typical characteristics of jumping species include long legs, large leg muscles, and additional limb elements.
Long legs increase the time and distance over which a jumping animal can push against the substrate, thus allowing more power and faster, farther jumps. Large leg muscles can generate greater force, resulting in improved jumping performance. In addition to elongated leg elements, many jumping animals have modified foot and ankle bones that are elongated and possess additional joints, effectively adding more segments to the limb and even more length.
Frogs are an excellent example of all three trends: frog legs can be nearly twice the body length, leg muscles may account for up to twenty percent of body weight, and they have not only lengthened the foot, shin and thigh, but extended the ankle bones into another limb joint and similarly extended the hip bones and gained mobility at the sacrum for a second 'extra joint'. As a result, frogs are the undisputed champion jumpers of vertebrates, leaping over fifty body lengths, a distance of more than eight feet.
Power amplification through stored energy
Grasshoppers use elastic energy storage to increase jumping distance. Although power output is a principal determinant of jump distance (as noted above), physiological constraints limit muscle power to approximately 375 Watts per kilogram of muscle. To overcome this limitation, grasshoppers anchor their legs via an internal "catch mechanism" while their muscles stretch an elastic
apodeme (similar to a vertebrate
tendon
A tendon or sinew is a tough, high-tensile-strength band of dense fibrous connective tissue that connects muscle to bone. It is able to transmit the mechanical forces of muscle contraction to the skeletal system without sacrificing its ability ...
). When the catch is released, the apodeme rapidly releases its energy. Because the apodeme releases energy more quickly than muscle, its power output exceeds that of the muscle that produced the energy.
This is analogous to a human throwing an arrow by hand versus using a bow; the use of elastic storage (the bow) allows the muscles to operate closer to isometric on the
force-velocity curve. This enables the muscles to do work over a longer time and thus produce more energy than they otherwise could, while the elastic element releases that work faster than the muscles can. The use of elastic energy storage has been found in jumping mammals as well as in frogs, with commensurate increases in power ranging from two to seven times that of equivalent muscle mass.
Classification
One way to classify jumping is by the manner of foot transfer. In this classification system, five basic jump forms are distinguished:
* Jump – jumping from and landing on two feet
* Hop – jumping from one foot and landing on the same foot
* Leap – jumping from one foot and landing on the other foot
* Assemblé – jumping from one foot and landing on two feet
* Sissonne – jumping from two feet and landing on one foot
Leaping gaits, which are distinct from
running
Running is a method of terrestrial locomotion allowing humans and other animals to move rapidly on foot. Running is a type of gait characterized by an aerial phase in which all feet are above the ground (though there are exceptions). This is ...
gaits (see
Locomotion), include
canter
The canter and gallop are variations on the fastest gait that can be performed by a horse or other equine. The canter is a controlled three-beat gait, while the gallop is a faster, four-beat variation of the same gait. It is a natural gait p ...
ing,
galloping, and
stotting or pronging.
[Tristan David Martin Roberts (1995) ''Understanding Balance: The Mechanics of Posture and Locomotion'', Nelson Thornes, .] Some sources also distinguish bounding as a cyclical motion of repeated jumps, used to maintain energy from one jump to the next.
Height-enhancing devices and techniques
The height of a jump may be increased by using a
trampoline
A trampoline is a device consisting of a piece of taut, strong fabric stretched between a steel frame using many coiled springs. Not all trampolines have springs, as the Springfree Trampoline uses glass-reinforced plastic rods. People bounce ...
or by converting horizontal velocity into vertical velocity with the aid of a device such as a
half pipe
A half-pipe is a structure used in gravity extreme sports such as snowboarding, skateboarding, skiing, freestyle BMX, skating, and scooter riding.
Overview
The structure resembles a cross-section of a swimming pool, essentially two concave ramps ...
.
Various exercises can be used to increase an athlete's vertical jumping height. One category of such exercises—
plyometrics—employs repetition of discrete jumping-related movements to increase speed, agility, and power.
It has been shown in research that children who are more physically active display more proficient jumping (along with other basic motor skill) patterns.
It is also noted that jumping development in children has a direct relationship with age. As children grow older, it is seen that their jumping abilities in all forms also increase. Jumping development is more easily identifiable in children rather than adults due to the fact that there are less physical differences at a younger age. Adults of the same age may be vastly different in terms of physicality and athleticism making it difficult to see how age affects jumping ability.
In 2021, researchers incorporated
ratchets into a robot design and created a robot capable of jumping over thirty meters vertically.
See also
*
List of jumping activities
The action of jumping is central to several sports and activities. Some sports are based almost exclusively on the ability to jump, such as high jump in track and field, whereas in other sports the act of jumping is one of multiple athletic abilit ...
*
Teleportation in fiction
References
External links
{{locomotion
Parkour techniques
Sports science
Terrestrial locomotion
Athletic sports
Physical exercise