# Hyperextension (exercise)

A back extension is an exercise that works the lower back as well as the mid and upper back, specifically the erector spinae muscles. There are two erector spinae, one on either side of the spine, that run along its length. These are formed of three smaller muscles – spinalis, longissimus, and iliocostalis.

## Hyperextension as a misnomer

The name hyperextension is commonly used for back extension exercises that are done using a hyperextension bench in a fitness gym. However the name 'hyperextensions' is a misnomer, because hyperextension means a movement where extension is performed at any joint beyond its normal range of motion. Instead, what one is trying to achieve in the back extension exercise is only to extend the spine within its normal range and not beyond its normal range of motion. When you extend the back from the flexed position, at the end range, your head and neck stays in neutral position.
In fact, back extension beyond the normal range of motion has been found to be detrimental for the exerciser. Hyperextensions during dead lift have been found to lead to lumbar disc pathologies and muscular spasms.

## Equipment used

Back extensions can be performed with or without various equipment.

### Without any equipment

    It may be performed on the ground by lying prone with arms overhead and lifting the arms, upper torso, and legs as far as possible. Gravity provides resistance to strengthen the back extensor muscles.

### Using a Roman chair

    A Roman chair helps to stabilize the legs up until the hip joints while performing low back extension. The torso from above the hip joints is flexed forwards and down towards the floor. The exercise is completed by contracting the back (erector spinae muscles) and raising the torso so the body is in a straight line from head to heels. The exercise can be enhanced by holding weights to the chest. Lighter weights may be used to begin with to prevent straining the back muscles with over-exertion. The weight may be held in a lower position by a beginner, then gradually held higher, to feel more resistance.

### Using a back extension bench (hyperextension bench)

    There are two varieties of back extension benches depending upon the angle that they support your lower body, the 45 degrees and 90 degrees back extension bench. The 90 degrees bench is also called a Roman chair. Here the body lies horizontally where the full range of motion is experienced. Using the 45 degree bench, the exerciser is almost standing, which allows extension only up to a partial range of motion. In both versions, the exerciser fold the arms in front or place the hands on the back of the head with the elbows pointing to the sides, while performing the exercise.

### Using a reverse back extension machine (reverse hyperextension machine)

    This machine has been used to strengthen not only the erector spinae muscle, but also gluteus maximus and part of hamstring muscles (biceps femoris). When back extension is attempted with this machine, the range of motion at hip is found to be relatively more, while the accompanying stresses at hip and back have been found not to relatively less.