Case Study: The Ephgrave Chair

Introducing the Ephgrave Chair

Caroline Ephgrave has worked as a physiotherapist for over twenty years, and began developing her own office chair, uniquely designed to provide specialised support to the spine, six years ago. After training as a dancer with the Royal Ballet, Caroline studied to become a physiotherapist at King's College London. Caroline's background has provided her with an in-depth understanding of movement and biomechanics, giving her a unique perspective whilst searching for a solution to the common and avoidable back issues which can be caused by using office chairs.

Using an office chair is a big part of most people’s day-to-day lives that we barely stop to think about. Problems with your back or neck, however, are harder to ignore. Spending long periods of time at a desk can lead to poor posture and cause back problems, as the spine is adversely aligned and the load is not evenly distributed. The subsequent restriction in movement affects many aspects of life, such as struggling to lift things, or with exercise and sports.

The Ephgrave chair aims to prevent this and focuses on supporting the keystone of the spine, which holds the body in a more balanced position and prevents slouching. The chair has a single, convex, moveable cushion that can be positioned at the balance point (keystone) of the spine for each user. The level of the keystone differs between individuals according to their dimensions and postural habits. By supporting this bone in line with gravity, the ribcage and head are balanced over a level pelvis: joint load is centralised and muscles can let go.


The unique design and concept of the Ephgrave chair brings awareness to how we sit and provides a different approach to preventing and treating back problems with the use of a small, adjustable cushion, designed to support a single keystone area of the back, and thus the whole spine. The cushion, which was designed with RGE, is easy to use and can be adjusted to suit each user. In the same way that you instinctively know exactly where to position a cushion behind you when sitting on a sofa, the adjustable curved cushion of the Ephgrave chair can be moved up and down, as well as forward and backward, so that the user can find the perfect position to support the correct parts of the back and improve posture. The domed cushion allows you to flex, arch and stretch your back throughout the day, mobilizing the stiffest joints in your back and improving overall mobility. Balancing the body also helps to release muscles in other places across the body, having widespread results.

The domed cushion was designed with RGE, and the original concept of an inflatable cushion was adapted to be more user friendly and provide better support. The curved cushion allows the chair to support the keystone of the spine, although it was a challenge to find the right curve and decide upon how firm the cushion should be whilst working virtually during Covid restrictions. The chair also allows and encourages the user to move – arm rests and huge cushioned backs can be limiting and cause you to twist in your lower spine as overall body movement is restricted.


RGE was able to help Caroline complete her vision for the innovative and distinctive design of the Ephgrave chair. Although it was difficult to work collaboratively during lockdown, Caroline was able to work closely with our designer Mark Temple. RGE provided support to amend parts of the initial design in order to create a more sleek and streamlined chair, moving the chair away from the initial aluminium prototype which was extremely heavy. Mark helped to design each part of the chair to ensure they fit together to create a cohesive and simple look. A lot of thought went into creating a chair that met the criteria for the dimensions of an office chair without it appearing bulky. Other parts of the chair also had to be decided upon, such as the finish and size of the back wings, mechanisms, clamps for the back cushion, alongside the logo and scale designs featured on the back of the seat. The length of the stem also had to be carefully designed and tested in order to meet the strength and dimension requirements to support any user. RGE sourced a bespoke gas lift specifically designed for the Ephgrave chair and used our in house upholstery team in our Lithuania factory to upholster the seat.

RGE’s Design team was able to help Caroline with a variety of the practical aspects of creating a chair that was both functional within an office setting, whilst providing the best support to the back. Mark worked with Caroline to further develop the original seat design to improve ergonomics, comfort and encourage mobility around the desk. The seat depth which is shorter than standard still provides support to body weight (as the body is balanced over the pelvis) but makes it easier to bring the chair in close enough to the desk to encourage use of the back support. Mark Temple kept the curved shape at the front of the seat with a waterfall edge for comfort. By choosing to omit arm rests, the chair is able to fit under the desk to allow the user to be closer to their keyboard without leaning forward, and also frees up the swivel action of the chair as arms often hit the desk. RGE have worked with Caroline to bring her innovative design into reality and since the products have been manufactured, RGE has stored them at their UK central distribution centre in Cambridgeshire where they are sent directly to customers.


Initially RGE began testing different materials for the parts of the chair, working towards passing tests and meeting classifications. The materials underwent strength testing and we trialed different compositions of glass filled nylon before we began making tools in order to put together prototypes of the new and improved designs of the chair in the UK. After the prototype was made, changes to the shape of the back of the chair to support the cushion were made, allowing the chair to balance the user correctly to help the foam  provide support.

The chairs have been manufactured and are now available to buy online at www.ephgravechair.com. Initial feedback has been extremely positive with users reporting increased comfort and flexibility at their desks. The chair will be exhibited at Clerkenwell Design Week (24-26th May) in London.

Caroline’s comment:
“I’ve really learned from the experience of working with RGE. For me, it was invaluable having a team with in-depth knowledge and experience of chair design to help me bring my vision to reality. Throughout the process, we worked together to find the best materials and solutions to bring out the features of the design and ensure the chair supports the spine – so blending the best of style and functionality. I am delighted that we now have the chair in production and am very grateful to all at RGE who helped to make this possible.”
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