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
Lost ball warrens, molehills or the like, or where there is a tree in the field of play and no local rule about what happens when it is hit. Previously 'lost ball' could only be called when the ball could not be found. This has resulted in some ridiculous local games where batsmen scored a large number of runs whilst the fielding side fetched a ladder to climb up a tree the ball had got lodged in. (The ball not being lost as it was readily visible.) The current version of the Law prevents this, as now 'lost ball' can also be