Gait (human)
Various gaits are characterized by differences in limb movement patterns, overall velocity, forces, kinetic and potential energy cycles, and changes in contact with the ground.
[6] In some individuals the gait pattern is largely unchanged (the leg and foot positions are identical in barefoot and shoes), but the wedge shape of the padding moves the point of impact back from the forefoot to the mid-foot.
[10] The central nervous system regulates gait in a highly ordered fashion through a combination of voluntary and automatic processes.
The basic locomotor pattern is an automatic process that results from rhythmic reciprocal bursts of flexor and extensor activity.
In contrast, immobilization involves injecting an acetylcholine inhibitor, which impedes the transmission of motor signals while sensory input is unaffected.
Visual, vestibular, proprioceptive, and tactile sensory information provides important feedback related to gait and permits the adjustment of a person's posture or foot placement depending on situational requirements.
Skin receptors, referred to as exteroceptors, provide additional tactile information about stimuli that a limb encounters.
Efferent signals from these regions go to the spinal cord where motor neurons are activated to regulate gait.
[12] Spinal reflexes not only generate the rhythm of locomotion through CPGs but also ensure postural stability during gait.
[12] Information from the spinal cord is transmitted for higher-order processing to supraspinal structures via spinothalamic, spinoreticular, and spinocerebellar tracts.
[11] The so-called natural gaits, in increasing order of speed, are the walk, jog, skip, run, and sprint.
[18] Initiation of gait is a voluntary process that involves a preparatory postural adjustment where the center of mass is moved forward and laterally prior to unweighting one leg.
The center of mass is only within a person's base of support when both feet are in contact with the ground (known as double limb stance).
Their results reveal skipping as more efficient and less fatiguing than walking or running and suggest the existence of a walk-skip rather than a walk-run transition at low gravity.
Meanwhile, as age increases, the cadence (rate at which someone walks that is measured in steps per minute) of the gait pattern decreases.
Physical attributes such as height, weight, and even head circumference can also play a role in gait patterns in children.
Environmental and emotional status also play a role in with speed, velocity, and gait patterns that a child uses.
Girls showed a smaller contact area in plantar loading patterns than boys in children with healthy feet.
[19] There are sex differences in human gait patterns: females tend to walk with smaller step width and more pelvic movement.
[21] Sex differences in human gait can be explored using a demonstration created by the BioMotion Laboratory at York University in Toronto.
[23] Kathyrn Knight of the Journal of Experimental Biology summarizes the findings of one study: "Landing heel first also allows us to transfer more energy from one step to the next to improve our efficiency, while placing the foot flat on the ground reduces the forces around the ankle (generated by the ground pushing against us), which our muscles have to counteract.
"[24] According to David Carrier of the University of Utah, who helped perform the study, "Given the great distances hunter-gatherers travel, it is not surprising that humans are economical walkers.
"[23] A normal gait pattern depends on a range of biomechanical features, controlled by the nervous system for increased energy conservation and balance.
It is therefore necessary for the refined neurological control and integration of these gait features for accuracy and precision with less energy expenditure.
[27][28][29][30][31] Recent studies have suggested that the first three determinants might contribute less to reducing the vertical displacement of the center of mass (COM).
[11] The most prominent example of gait irregularities due to developmental problems comes from studies of children on the autism spectrum.
The author of the Deuterocanonical Book of Sirach observes that "a man's attire, and excessive laughter, and gait, shew what he is".
