the point of contra flexure is a point where
Contraflexure In a bending beam, a point is known as a point of contraflexure if it is a location at which no bending occurs. It is also known as an inflection point. In a bending moment diagram, it is the point at which the bending moment curve intersects with the zero line. In other words where the bending moment changes its sign from negative to positive or vice versa. Knowing the place of the contraflexure is especially useful when designing reinforced concrete or structural steel beams and also for designing bridges.
Hypermobility (joints) Hypermobility, also known as double-jointedness, describes joints that stretch farther than normal. For example, some hypermobile people can bend their thumbs backwards to their wrists, bend their knee joints backwards, put their leg behind the head or perform other contortionist "tricks". It can affect one or more joints throughout the body.