Most people who lived through the 1980s would agree that the fashions and fads of the time were, euphemistically speaking, not entirely practical. The era of power hair, neon sunglasses, and the jelly shoe provided another curiosity in clothing; Jams. Not quite trousers1 and not quite shorts. Instead they are a mix of the two.
Jams are almost 100% polyester, and contain almost no natural fabrics. That's okay, because they rarely contain colours or patterns found in nature, either. Instead they made liberal use of fluorescent colours and weird angular patterns.
When trying on a pair of Jams, you may be surprised to find that though the tag indicates your size, the actual sensation of wearing them may take a little getting used to. For one thing, they tend to bond to the buttocks in a manner which is most aggravating. The cuff of the trouser legs falls midway down the shin, in a disturbingly 'non-trouser like yet non-shorts like manner'. Rest assured, however, Jams were designed to fit this way - and the fashion-conscious, at the time, thought they looked really good.