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Running is a method of terrestrial locomotion by which humans and other animals move rapidly on foot. Running is a gait with an aerial phase in which all feet are above the ground (though there are exceptions). This is in contrast to walking, where one foot is always in contact with the ground, the legs are kept mostly straight, and the center of gravity vaults over the stance leg or legs in an inverted pendulum fashion. A feature of a running body from the viewpoint of spring-mass mechanics is that changes in kinetic and potential energy within a stride co-occur, with energy storage accomplished by springy tendons and passive muscle elasticity. The term "running" can refer to a variety of speeds ranging from jogging to sprinting. Running in humans is associated with improved health and life expectancy. It is hypothesized that the ancestors of humankind developed the ability to run for long distances about 2.6 million years ago, probably to hunt animals. Competitive running grew out of religious festivals in various areas. Records of competitive racing date back to the Tailteann Games in Ireland between 632 BCE and 1171 BCE, while the first recorded Olympic Games took place in 776 BCE. Running has been described as the world's most accessible sport. History It is thought that human running evolved at least four and a half million years ago out of the ability of the ape-like Australopithecus, an early ancestor of humans, to walk upright on two legs. Early humans most likely developed into endurance runners from the practice of persistence hunting of animals, the activity of following and chasing until a prey is too exhausted to flee, succumbing to "chase myopathy" (Sears 2001), and that human features such as the nuchal ligament, abundant sweat glands, the Achilles tendons, big knee joints and muscular glutei maximi, were changes caused by this type of activity (Bramble & Lieberman 2004, et al.). The theory as first proposed used comparative physiological evidence and the natural habits of animals when running, indicating the likelihood of this activity as a successful hunting method. Further evidence from observation of modern-day hunting practices also indicated this likelihood (Carrier et al. 1984). According to Sears (p. 12) scientific investigation (Walker & Leakey 1993) of the Nariokotome skeleton provided further evidence for the Carrier theory. Competitive running grew out of religious festivals in various areas such as Greece, Egypt, Asia, and the East African Rift in Africa. The Tailteann Games, an Irish sporting festival in honor of the goddess Tailtiu, dates back to 1829 BCE and is one of the earliest records of competitive running. The origins of the Olympics and Marathon running are shrouded by myth and legend, though the first recorded games took place in 776 BCE. Running in Ancient Greece can be traced back to these games of 776 BCE. ...I suspect that the sun, moon, earth, stars, and heaven, which are still the gods of many barbarians, were the only gods known to the aboriginal Hellenes. Seeing that they were always moving and running, from their running nature they were called gods or runners (Thus, Theontas)... Description Running gait can be divided into two phases regarding the lower extremity: stance and swing. These can be further divided into absorption, propulsion, initial swing, and terminal swing. Due to the continuous nature of running gait, no certain point is assumed to be the beginning. However, for simplicity, it will be assumed that absorption and footstrike mark the beginning of the running cycle in a body already in motion. Footstrike Footstrike occurs when a plantar portion of the foot makes initial contact with the ground. Common footstrike types include forefoot, midfoot, and heel strike types. These are characterized by initial contact of the ball of the foot, ball and heel of the foot simultaneously and heel of the foot respectively. During this time, the hip joint is undergoing extension from being in maximal flexion from the previous swing phase. For proper force absorption, the knee joint should be flexed upon the footstrike, and the ankle should be slightly in front of the body. Footstrike begins the absorption phase as forces from initial contact are attenuated throughout the lower extremity. Absorption of forces continues as the body moves from footstrike to midstance due to vertical propulsion from the toe-off during a previous gait cycle. Midstance Midstance is when the lower extremity limb of focus is in knee flexion directly underneath the trunk, pelvis, and hips. At this point, propulsion begins to occur as the hips undergo hip extension, the knee joint undergoes extension, and the ankle undergoes plantar flexion. Propulsion continues until the leg is extended behind the body and toe-off occurs. This involves a maximal hip extension, knee extension, and plantar flexion for the subject, resulting in the body being pushed forward from this motion, and the ankle/foot leaves the ground as the initial swing begins. Propulsion phase Recent research, especially in the footstrike debate, has primarily focused on identifying and preventing injuries during the absorption phases of running. The propulsion phase, which occurs from midstance to toe-off, is crucial for understanding how the body moves forward. In a full stride length model, elements of both the terminal swing and footstrike contribute to propulsion. The setup for propulsion begins at the end of the terminal swing when the hip joint flexes, allowing the hip extensors to generate force as they accelerate through the maximal range of motion. As the hip extensors transition from inhibitory to primary muscle movers, the lower extremity moves back towards the ground, aided by the stretch reflex and gravity. The footstrike and absorption phases follow, leading to two possible outcomes. With a heel strike, this phase may be just a continuation of momentum from the stretch reflex, gravity, and light hip extension, offering little force absorption through the ankle joint. On the other hand, a mid/forefoot strike helps in shock absorption, supporting plantar flexion from midstance to toe-off. Actual propulsion begins as the lower extremity enters midstance. The hip extensors continue contracting, assisted by gravity and the stretch reflex from maximal hip flexion during the terminal swing. Hip extension pulls the ground underneath the body, propelling the runner forward. During midstance, the knee should be slightly flexed due to elastic loading from the absorption and footstrike phases, preserving forward momentum. The ankle joint is in dorsiflexion at this point, either elastically loaded from a mid/forefoot strike or preparing for stand-alone concentric plantar flexion. The final propulsive movements during toe-off involve all three joints: ankle, knee, and hip. The plantar flexors push off from the ground, returning from dorsiflexion in mi.... Discover the Gretchen Reynolds popular books. Find the top 100 most popular Gretchen Reynolds books.