Know your chair – Know where it comes from – Know the tools to be used
Knowing where your wheelchair was manufactured, will give you an indication to which are the right tools to use.
Wheelchairs manufactured in the US will generally if not always use Imperial size bolts and screws (i.e. inches and feet) etc. whereas wheelchairs manufactured in Australia, Europe or Asia will use Metric sizes (i.e. millimetres, centimetres and metres).
Right tool = less hassles
The right or correct fitting tool makes it easier to undo bolts and screws and causes fewer problems in the long run.
Use physics – Leverage, leverage, leverage
Often on new wheelchairs bolts can be machine tightened or done up extremely tight. This makes it difficult to undo these using T-handled allen keys, screw drivers and other tools with short levers. To overcome this use L-shaped allen keys with an extension on the lever arm to get maximum leverage and decreased resistance.
What makes up the ideal tool kit for therapists?
The following suggestions of tools cover a broad variety of wheelchairs and allow most of the common adjustments and repairs to be done:
- Spanners – 3/8", 7/16", ½"/ 10mm, 11mm, 13mm
- A socket set can make life easier but is occasionally harder to gain access to the bolts.
- Sometimes two of the same size spanners are required – one to hold the bolt head and one to hold the nut.
- Adjustable Wrench – this can be used for the odd sizes that the above spanners don’t fit.
- Allen Keys – 1/8", 5/32", 3/16" / 3mm, 4mm, 5mm
- T-handled allen keys are great for quick adjustments but have very little leverage for tight, stubborn bolts. They also limit access to awkward screws and bolts, whereas L-shaped allen keys give you good leverage for tight bolts and you can use either end of the allen key. They are generally purchased in a set so you have just about all the options covered.
- Phillips Head
- Flat Head
- Stanley Knife
- Sticky back Velcro – enough said
Common adjustments to wheelchairs and their clinical implications
Adjusting the rake/dump/seat to floor heights on a manual wheelchair
Front Seat to floor height
- Overall height for transfers
- Pressure redistribution on thighs and ITs
- Changes Rake – impact on hip angle
- Changes back angle
- Castor angle
Rear seat to floor height
- Overall height of user – function and environment
- Pressure redistribution on IT’s and thighs
- Shoulder position in relation to rear wheels
- COG & Stability
- Sliding side to side transfers
- Castor angle
- Sitting posture
Change the castor angle
- Wrong castor angle = Poor performance = Extra strain on shoulders and difficulty pushing
- Decreases manoeuvrability
- Dangerous at high speeds
Adjust the centre of gravity on a wheelchair
- Increase manoeuvrability
- Decrease strain on shoulders
- Increase ‘tippiness’
- Dependent on sitting balance
- Consider extras/additions usually on wheelchair
- Decrease overall footprint/wheelbase of wheelchair (can make it harder to get up curbs/gutters)
- Body dimensions (weight distribution)
- Seat depth/frame length
Adjust the camber angles
- Base width
- Rear wheel spacing
- Doorway widths
Where did I go wrong and what do I do now – Common problems
Using incorrect size of allen key, spanners, wrenches and even screwdrivers
This can result in the stripping of bolt heads, allen key bolts and screws especially on tight critical bolts. If the bolt is completely stripped and is impossible to remove its time to call in the service team because the bolt will need to be cut off or drilled out.
Not using advantages at our disposal
Consider the tools that you are using and if they are offering you the greatest physical advantage. Use long levers and the right fitting tool – Work smarter not harder.
Adjusting clamp style attachments
Predominantly seen in brake assemblies, a common mistake is to undo one of the two bolts a majority of the way – this creates an additional force on the second bolt and makes it extremely hard to remove (even if you use the right size tool and an appropriate size lever). In this case tighten the first bolt and undo the two bolts at the same time (about ½ a turn each bolt) until both have loosened.
Bolts into threaded vs smooth holes
If screwing into threaded holes ensure bolt is tightened prior to attaching nut and tightening that.