Manual wheelchairs are of different varieties and designs which include rigid and folding frames. Yet these frames differ in the way that they are designed, constructed and the way they function. This makes each design unique and you will have to be careful when deciding to rent or purchase one.
To make the right decision and choose what is right for you, there are several factors that you must consider. These include:
- The type of material used in fabricating the frame of the wheelchair.
- The design and type of wheelchair frame that you are choosing.
- What are the components included in the wheelchair and if they can or cannot be separated from the frame? This is essential when it comes to weight and size for storage and transportation.
- Types of adjustments that you can make to fit your needs such as posture, comfortability as well as efficiency when it comes to better propulsion.
This will determine the wheelchair strength, durability, and weight. Durability depends on the ratio of the frame material strength to the ratio of the weight. A wheelchair will be durable if the material used to design and construct the frame has a higher strength ratio over the weight ratio. Below is a summary of the variations, pros, and cons of different materials to consider when making your decision.
This material has a higher strength to weight ratio as compared to aluminium and that means it requires less material when constructing the frame. With titanium, it is easy to create a lighter frame. Besides, it has high fatigue life and this makes it hard to bend or get damaged. Also, it is resistant to corrosion, unlike aluminium that requires an additional coating to protect it. Apart from that, it has been discovered that titanium has a dampening effect which helps to reduce vibration when propelling. Studies are still being made to confirm this.
It is a metal that is economical and easy to fabricate. The 7000 series aluminum has proven to be much stronger as compared to the earlier versions as less material is needed to fabricate and hence weight is reduced. The negative side of it is that there are higher chances of structural damage to the frame in case it is exposed to strains. This depends on the shape and design of the frame as some are constructed with support tubes while others are designed in a cantilever style.
Recently carbon fiber has been introduced in the manufacturing of manual wheelchairs. This material is very light, stiff and corrosion-resistant. The downside of it is that it is expensive and hard to shape. Besides, it has poor impact-resistant where it can be damaged easily. This makes it be used only on some components to reduce the overall weight of the wheelchair.
The style and components used to make the wheelchair frame will determine the weight of the wheelchair as the base can only cover less than a pound. Even if the frame is not made from titanium the wheelchair must still be lighter.
Weight consideration in your decision making
You have two decisions when considering weight:
- The overall weight of the wheelchair,
- The lifting weight that involves the total frame and other components’ weight as well as the seat cushion and the back support.
When the overall weight is reduced it makes it easy for the user to propel the wheelchair. Besides, it helps to improve the durability and efficiency of the frame. Remember that during the manufacturing process a wheelchair can start with a lightweight frame and end up installing heavy wheelchair system components such as wheels, seat cushions, braking systems, etc.
It is also possible to have a heavy wheelchair that is well configured allowing the wheel propulsion to require less energy making it efficient and easy to propel. You have to be careful when making a comparison of the wheelchairs’ weights especially when the wheelchairs are from different manufacturers as the base weights are weighed differently depending on which components are installed or not.
Folding Frames Vs Rigid Frames
- Folding manual wheelchair: Normally this has always been regarded as a cross-brace design as the frame folds by half making the sides of the wheelchair slide coming together. Recently there has been a scissor-brace frame design on wheelchairs such as the Kuschall Champion brand design that gives the user the ability to fold and unfold the wheelchair from either side.
The cross-brace frame is designed in such a way that it involves many moving parts that allow the chair to fold. This adds weight to the frame although this has been improved. You can find them in both materials such as aluminium, titanium and carbon fiber. Initial designs comprised of only footplates which were able to flip up out to allow stand transfers. The design was improved and swing-away leg rests as well as removable arms got included. This made the wheelchairs lighter as some of the components were left out. Some of the wheelchairs come with quick-release axles that help to reduce the transfer weight as well as the size making the chair fit in small vehicles. There is a new version of the scissor-brace that folds by pulling in the release system from the front of the wheelchair. This makes it possible for the user to reach and fold it easily.
- Rigid Manual Wheelchairs
The design concept for developing this wheelchair came from sports wheelchairs. Initially, the frame was made out of aluminium but later titanium started to be used as well as carbon fiber. Aluminium is mostly used in sports wheels as it makes the user use less energy while in propulsion. This design has few moving parts and this makes the wheelchair base lighter. The advantage of this chair being light is that each push makes the chair move further with less energy.
There are two main types of rigid manual wheelchair frames. The first is designed into a monotube which is a single continuous tube that leaves the lower side of the chair open. This makes it easy to bring closer and across the body when you want to transport your wheelchair by a vehicle. Besides less tubing, it leads to a drop in the weight of the frame. Using titanium to design a frame creates a flex which is good for a soft ride but it requires the user to use extra energy for a push. Some people prefer a soft ride because it makes them feel more comfortable so they do not mind using extra effort for the push.
The second design of a rigid frame is designed in a form of a box where it is designed in such a way that it has added support tube that helps in adding rigidity below the frame, as a result, there is less loss of energy. This makes the chair have more space meaning that it is wider or deeper below thus taking up extra space over the body when being transferred into the vehicle. The advantage of this kind of frame is that it offers more stability as well as efficiency in propulsion.
Fixed front ends
Normally rigid frames have fixed front ends and this means that they never move out of the way for standing transfers. If you would like to have one of these then look for the one that has a single side flip-up footplate which opens the front area of the wheelchair when making a transfer. You should try the frame and see how it works before you decide to buy it. And when it comes to folding frames quick-release axles will enable you to easily remove the wheels.
Fixed and adjustable frames
Rigid frames are found into two categories which are fixed and adjustable frames. If you are using a chair and you already know your exact measurements of the frame as well as the angles, you can order a custom made wheelchair that cannot be adjusted as it will come with the measurements that suit you. If you are not sure of your exact body measurements, then an adjustable frame will be better for you.
Configuration of your wheelchair
If you are fit enough to propel your chair whether it is a manual or rigid frame, remember that one of the important things is the proper wheel alignment. This must be assessed by a professional or by the OT/PT. Proper wheel alignment is essential in protecting your shoulders and wrist as well as providing energy efficiency push-stroke. The wheels must be aligned with the shoulders and fingers to easily reach the axle.
This is normally based on the ability to balance the wheelchair depending on trippiness and it also depends on your skills and ability to manage the wheelchair with its wheels in a more forward alignment. For newly injured people should start practicing with the wheels further back until they have gained their strength, skills as well as trunk balance.