Mountainous region, northwestern Myanmar (Burma). Extending along the Indian border, it forms the central part of an arc that stretches from the Arakan Mountains to the Patkai Range. The Chin Hills vary from 7,000 to 10,000 ft (2,000 to 3,000 m) high. They and the arc are part of the north-south-trending mountain belt of Southeast Asia, which has hindered east-west movement; the region was populated by the Chin peoples from the north. It is a frontier zone between Myanmar and Indian cultures.
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Province (pop., 2002 est.: 32,940,000), northern China. It is bordered by Hebei, Henan, and Shaanxi provinces and Inner Mongolia. It has an area of 60,700 sq mi (157,100 sq km). The capital is Taiyuan. Largely a vast plateau covered by great loess deposits, it was the home of early Chinese agriculture. Most of the people are Han Chinese; other ethnic groups include Hui (Chinese Muslims), Mongols, and Manchus. Since ancient times it has been an integral part of the various northern kingdoms of China, serving as a buffer against invaders from the north and as a key trade route. It was one of the major avenues by which Buddhism came to China from India. After the overthrow of the Qing dynasty in 1911–12, the warlord Yan Xishan ruled as absolute dictator until the end of World War II. Japan occupied part of the province during the Sino-Japanese War (1937–45). Communist forces assumed control of Shanxi in 1949. It has vast reserves of coal and iron and the largest titanium and vanadium deposits in China and is a major producer of cotton.
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Chin-up bars are playground equipment that were once ubiquitous on children's playgrounds. They are still important in the adult equivalent of a playground, the Par course. A chin-up bar is simply a smooth horizontal metal bar, often a pipe, held solidly above ground by a wooden or metal frame. Typical installations include 2 or 3 different heights of bars for people of different heights.
In its common usage, a person jumps up slightly to grab the bar in both hands so that the palms are facing away and the feet hang freely in the air. The exerciser then pulls himself up to where his chin passes the top of the bar, slowly lowers himself to hanging by his arms, and repeats as many times as possible. This is referred to commonly as a pull-up.
The chin-up can also be performed using an inverse grip, where the palms of the hands are facing the participant. This is what is commonly referred to as a chin-up. This type of grip usually places more emphasis on the intercostals and the biceps, whereas the traditional grip is more of an upper-back and latissimus dorsi exercise.
Further variations on chin-ups are possible by gripping with only a few fingers of one hand in order to increase resistance on the other arm. This type of exercise should be balanced evenly on both arms. One-armed chin-ups are also possible but are notoriously difficult to achieve.
Chin-up bar counts were once a part of the U.S. President's Council on Physical Fitness program for evaluating the physical health of schoolchildren in the 1960s and 1970s.
Children found other creative ways to use them, however, such as hanging by the knees, pulling oneself up to the top and sitting on them (more common with monkey bars variation), and so on.