<unk>  is the main form of animal locomotion on land, distinguished from running and crawling.  When carried out in shallow waters, it is usually described as wading and when performed over a steeply rising object or an obstacle it becomes scrambling or climbing. The word<unk>  is derived from the Old English walkan (to roll).<unk>  is generally distinguished from running in that only one foot at a time leaves contact with the ground: for humans and other bipeds running begins when both feet are off the ground with each step. (This distinction has the status of a formal requirement in competitive<unk>  events, often resulting in disqualification  even at the Olympic level.) For horses and other quadrupedal species, the running gaits may be numerous, and<unk>  keeps three feet at a time on the ground.
The average human child achieves independent<unk>  ability between nine and fifteen months old.
While not strictly bipedal, several primarily bipedal human gaits (where the long bones of the arms support at most a small fraction of the body's weight) are generally regarded as variants of<unk> .  These include:
Hand<unk> ; an unusual form of locomotion, in which the walker moves primarily using his hands.<unk>  on crutches (usually executed by alternating between standing on both legs, and rocking forward "on the crutches" (i.e., supported under the armpits by them);<unk>  with one or two<unk>  stick(s) or trekking poles (reducing the load on one or both legs, or supplementing the body's normal balancing mechanisms by also pushing against the ground through at least one arm that holds a long object);<unk>  while holding on to a walker, a framework to aid with balance; and
scrambling, using the arms (and hands or some other extension to the arms) not just as a backup to normal balance, but, as when<unk>  on talus, to achieve states of balance that would be impossible or unstable when supported solely by the legs.
For humans,<unk>  is the main form of transportation without a vehicle or riding animal. An average<unk>  speed is about 5 km/h (3 mph), although this depends heavily on factors such as height, weight, age and terrain. A pedestrian is a<unk>  person, in particular on a road (if available on the sidewalk/path/pavement).
Walking
Scoop and Run
Burping
Kegel exercise
Quenching 
Walk through angina pectoris
Aerobic exercise
Breathing