Stress ball
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A stress ball is a malleable toy, usually not more than 7cm in diameter. It is squeezed in the hand and manipulated by the fingers, ostensibly to either help relieve stress and muscle tension or to exercise the muscles of the hand.
There are many types of stress balls. Many are a closed-cell foam rubber. Others contain gel of different densities, especially those used in physical therapy. Another type uses a thin rubber membrane surrounding a fine powder. The latter type can be made at home by filling a balloon with baking soda. Some balls, similar to a footbag are marketed and used as stress balls.
Despite the name, many stress balls are not spherical. Many stress toys are molded in amusing shapes and printed with corporate logos. They are presented to employees and clients as gifts and marketing pieces. Stress toys are a staple of cubicles where repetitive stress injuries such as carpal tunnel syndrome are common.