The core is made up of the trunk and the associated muscles. The extremities include the forearms and hands, hands, thighs, legs and ankles/feet. Strong core muscles are essential for extremities to be able to attach to each other and perform more efficiently. The theory is that a weak core can put excessive strain on the extremity muscles and tendons, ligaments, and joints. Core strengthening involves multi-joint exercises that involve larger muscle groups, such as the abdominals, chest, back, hip/thigh and shoulder blade muscles. Core strengthening is often integrated into a neck or low back rehabilitation program. Core strengthening is often part of a program for arm, leg, ankle, or forearm rehabilitation. It provides stability for the extremities and recovery or enhancement of core power