The outsole may comprise a single piece, or may be an assembly of separate pieces, often of different materials. On some shoes, the heel of the sole has a rubber plate for durability and traction, while the front is leather for style. Specialized shoes will often have modifications on this design: athletic or so called cleated shoes like soccer, rugby, baseball and golf shoes have spikes embedded in the outsole to improve traction. The is the layer in between the outsole and the insole, typically there for shock absorption. Some types of shoes, like running shoes, have additional material for shock absorption, usually beneath the heel of the foot, where one puts the most pressure down. Some shoes may not have a midsole at all. The heel is the bottom rear part of a shoe. Its function is to support the heel of the foot. They are often made of the same material as the sole of the shoe. This part can be high for fashion or to make the person look taller, or flat for a more practical and comfortable use. On some shoes the inner forward point of the heel is chiselled off, a feature known as a "gentleman's corner". This piece of design is intended to alleviate the problem of the points catching the bottom of trousers and was first observed in the 1930s. A heel is the projection at the back of a shoe which rests below the heel bone. The shoe heel is used to improve the balance of the shoe, increase the height of the wearer, alter posture or other decorative purposes. Sometimes raised, the high heel is common to a form of shoe often worn by women, but sometimes by men too. See also stiletto heel. The helps hold the shoe onto the foot. In the simplest cases, such as sandals or flip-flops, this may be nothing more than a few straps for holding the sole in place. Closed footwear, such as boots, trainers and most men's shoes, will have a more complex upper. This part is often decorated or is made in a certain style to look attractive. The upper is connected to the sole by a strip of leather, rubber, or plastic that is stitched between it and the sole, known as a welt. Most uppers have a mechanism, such as laces, straps with buckles, zippers, elastic, velcro straps, buttons, or snaps, for tightening the upper on the foot. Uppers with laces usually have a tongue that helps seal the laced opening and protect the foot from abrasion by the laces.