V-Trak Backrest, User Manual, Page: 7 / 32

Installing all Mounting Blocks except MB-UN (Netti & ETAC)
Determine the most suitable position for the mounting blocks. Unless there are obstructions on the
uprights or other limiting factors, the optimum location for the backrest pivot point will be at
approximately as shown in Figure 3A.Typically this will be approximately 60% of the distance from
the bottom to the top of the backrest track. Each case will be different according to the client’s
body mass and likely behaviour. Every effort should be made to balance the likely rotational forces
above and below the pivot point.
The optimum balance point may not be practical due to obstructions on the wheelchair uprights or
other reason. If installations such as Figure 3B or 3C are required, it may be necessary to use a
secondary arm at the top for 3B or at the bottom for 3C. Sometimes, a four point attachment
configuration may be required to accommodate any excessive forces.
Installation instructions for standard mounting blocks:
1. Remove the canvas backrest from the wheelchair according to the manufacturer’s
recommended procedures.
2. Remove the Mounting Blocks from their packing and dismantle
3. Using the 5mm Key wrench, remove the two screws Figure 4 (1) from the mounting block and
withdraw the tightening wedges (2 and 3) and the pin block (4)
4. Install one Mounting Block at the optimum height for the backrest, ensuring the screw holes
are to the outside of the wheelchair and accessible for final positioning. Repeat the process for
the second mounting block on the opposite side but approximately 50mm lower than the first
block.
5. Ideally the mounting blocks should be facing inward at an angle of approximately 45 degrees
but they can be used in a parallel configuration to the front or rear of the wheelchair. If the
tubes are not of round section the special blocks available cannot be rotated but they can be
mounted to the front or rear of the uprights or in intermediate positions depending on the cane
profile
6. Do not over tighten at this stage. Allow the mounting block to rotate under moderate pressure.
3A 3B 3C
1
2 & 3
Figure 4
4
Figure 3