Exercise ball standard exercises, such as a push-up, on an unstable surface can be used to increase activation of core trunk stabilizers and in turn provide increased trunk strength and greater resistance to injury. Fitness Experts and some doctors also recommend sitting on an exercise ball instead of an office chair. That is based on the theory that the abdominal and back muscles are constantly engaged and active to maintain proper posture and balance on the ball. There is no scientific evidence of those benefits occurring by just sitting without additional exercises. However, some people warn against using a Swiss ball as
Ball-in-a-maze puzzle maze. Perplexus is an example of a 3D ball-in-a-maze. Recently a large number of virtual versions have become available. Another version, usually molded in transparent plastic, uses the ball as a key to opening an internal compartment by manipulating the ball into position, and then operating a sliding mechanism that releases an access door. They are sometimes called "Money Maze" banks or puzzle boxes. Ball-in-a-maze puzzle Ball-in-a-maze puzzles are dexterity puzzles which involve manipulating either a maze (or labyrinth) or one or several balls so that the ball or balls are manoeuvered towards a goal. Toys like this have been