UI HydroCare. iss1 06/11
2. Seat Depth
4
It is important to set seat depth correctly in order to
prevent ‘sacral sitting’ and to achieve the best distribution
of weight between the client and the chair. Sacral sitting
occurs when the pelvis tilts backwards so that the lower
back (sacrum), as well as the bottom, is resting on
the seat cushion. The sacral area can be susceptible to
pressure problems. Sacral sitting will occur if the seat
depth is too long. If the seat depth is too short then
the client’s body weight will be concentrated in too small
an area.
With the HydroCare seat depth also affects arm height.
The chair has been sized so that as the seat depth is
increased it is matched by a proportionately higher arm
height.
Seat depth should be set with the client’s bottom
positioned
fi
rmly at the back of the seat cushion so
that their lower back and lumbar is supported by the
back cushion. There needs to be a two or three
fi
nger
gap between the client’s calf and the front of the seat
cushion for comfort.
If the client already has a chair or wheelchair with the
correct seat depth, measure this size and use it to set
up the HydroCare
Seat depth is adjusted by moving the back of the chair
over the seat unit. The front edge of the seat will stay in
the same place. The seat depth mechanism is controlled
by two handwheels on the underside of the seat board,
one each side of the seat.
Before adjusting seat depth, apply the
brakes on all castors. Do not attempt to
adjust seat depth when someone is sitting
in the chair.
To adjust seat depth, loosen the
handwheels until they are felt to hang
freely from the underside of the seat.
They do not need to be removed.
Hold onto the square tube at the back of
the seat depth frame, each side of the gas
action and push/pull the seat back to the
desired position.
Once the back is in the correct position
ensure that it looks square and is not
twisted. Tighten the handwheels on the
underside of the seat board to lock the
back in place and therefore
fi
x the seat
depth.
Seat Too Short;
Increase in pressure
beneath the bottom.
Seat Too Long;
Increased pressure on bottom,
sacrum and shoulders.
Undo the handwheels on the underside, outer
edges of the seat board.
