What is DUMP and Why is it Important?

The Rollin’ RNs are always on the lookout for questions that may need some explanation in our wheelchair community. And here is a topic that comes up now and again that we thought fit right into this category. When you hear the word “dump” or “slope” when it’s in reference to our chairs, what exactly does that mean? Let us explain:

The seat angle is usually referred to as the "dump" and it is measured by how much lower the rear of the seat is than the front of the seat. A seat that is 2" lower at the back than the front would be said to have a 2" dump. This is a pretty simple definition to explain “dump” but the next question is why is “dump” important to those in wheelchairs with spinal cord injuries?

“Seat slope or seat inclination is used for various reasons,” says Steve Boucher, OT, clinical educator for Sunrise Medical. “When we look at positioning, seat inclination is sometimes used to prevent a client from sliding forward in their chair.”

Boucher adds that seat slope can give self-propelling chair users better accessibility to their rear wheels, “especially those users who are very tall through their upper body. It allows a user to sit ‘in’ their chair rather than ‘on top’ of their chair. This affects the end user’s center of gravity and can make for better propulsion technique, which leads to someone not fatiguing as quickly in their chair.”

Tricia Garven, PT, ATP, clinical applications manager for The ROHO Group explains “the lower you sink somebody’s butt — basically, the greater that difference (in height) is from the front to the back — the more it makes up for in terms of lack of physical ability. You have more stability and you have more balance the lower you sink them. The lower we sink your butt, the more it makes up for in terms of what you lack in ability in your trunk and your core.”

Christopher Bittner, ATP, Numotion, provided an illustration and explained it, seat slope is the difference between the front seat to floor height and the rear seat to floor height. Here are a couple diagrams that show you exactly what I am referring to. Letter C shows the front seat to floor height and letter D shows the rear seat to floor height.

There it is…since many of us lack some type of basic trunk control, the “dump” was created to assist with balance while in our chair. Ultimately, the less trunk control, the more dump.

While seat slope is a common topic of conversation for people with spinal cord injuries, the seat slope factors to consider can be very different for clients with other diagnoses states Kevin Phillips, ATP/SMS, CRTS, Experea Health Care of Lake Forest (Calif.).

It’s all good, so keep on rollin,’

Patty, BSN, RNC and Roberta, RN

The Rollin’ RNs ™

References:

Seat Slope’s Sweet Spot. https://mobilitymgmt.com/articles/2012/08/01/optimal-seat-slope.aspx.