Hyperextension is an excessive joint movement in which the angle formed by the bones of a particular joint is opened, or straightened, beyond its normal, healthy, range of motion. Such a movement may potentially make that particular joint unstable, and in turn, increase the risk and likelihood for dislocation or other potential injuries of the joint.
Occasionally, hyperextension is referred to as a normal movement, or exercise, that positions a body part or limb posteriorly (towards the back) of the anatomical position. An example of this type of exercise is the superman exercise where the back is hyperextended compared with a normal anatomic position.
Range of Motion
A majority of the human body’s joints allow for certain movement. A few particular joints, like joints in the skull, do not. Those joints that do allow for motion, such as the knee or ankle, have a predetermined range of motion. This range of motion is basically how far in each direction that joint can move or bend comfortably. For example, think of the neck. You can move your neck to a certain extent in each direction, but if you turn your neck too far in one particular direction injuries can occur. The range of motion of a joint is usually measured in degrees. Each individual joint has a separate range of motion.
The opposite of hyperflexion is flexion. Flexion is defined as the bending of a particular joint so that the bones that form that joint are pulled closer together. During flexion, the angle between the bones of limbs at a joint is decreased. Flexion typically occurs when muscles contract and the bones thus move the nearby joint into a curved position. In short, flexion shortens a joint angle and extension increases it.
In terms of physical fitness, hyperextension is also a type of exercise that works that middle and lower back.
A hyperextension exercise can be performed by lying face down on the floor and then lifting the arms and the torso off the ground while keeping the hips and lower body even and grounded. This movement stretches muscles in the lower back. There are also pieces of equipment commonly found in gyms that can be utilized to perform hyperextension exercises. If you are unsure of which pieces of equipment to utilize in order to perform hyperextension exercises, be sure to ask a member of the staff at your gym.
Example: The whiplash injury caused him to hyperextend his neck.