Most commonly, patients describe acute tenderness in the buttock and sciatica-like pain down the back of the thigh, calf and foot. Typical piriformis syndrome symptoms may include: 1  A dull ache in the buttock. 2  Pain down the back of the thigh, calf and foot (sciatica). 3  Pain when walking up stairs or inclines.
There are currently 10 sectors and 68 industries. Three of the 68 industries do not have companies represented in the S&P 500 Index; therefore, performance is not available for Marine, Transportation and Infrastructure, and Water Utilities.
The Four Types of Industry Infrastructures. Pizza companies are members of the monopolistic competition industry infrastructure. Ablestock.com/AbleStock.com/Getty Images. Industries operate on the basis of products, target consumers and geographical reach. Each industry, in turn, comprises numerous firms. Economists contend that there are four basic types of industry infrastructures, writes Case Karl in his book âPrinciples of Economics.â These include perfect competition, pure monopoly, monopolistic competition and oligopoly.