Structure of wheelchair
Ordinary wheelchairs generally consist of four parts: wheelchair frame, wheels, brake device and seat. As shown in the figure, the functions of each main component of the wheelchair are described.
Large wheels: carry the main weight, the diameter of the wheel is 51.56.61.66cm, etc. Except for a few solid tires that are required by the use environment, others use pneumatic tires.
Small wheel: There are several diameters such as 12.15.18.20cm. The small diameter wheels make it easy to negotiate small obstacles and special carpets.However, if the diameter is too large, the space occupied by the entire wheelchair becomes larger, making movement inconvenient. Normally, the small wheel comes before the big wheel, but in wheelchairs used by people with lower limb paralysis, the small wheel is often placed after the big wheel. During operation, attention should be paid to making sure that the direction of the small wheel is perpendicular to the big wheel, otherwise it will easily tip over.
Wheel rim: unique to wheelchairs, the diameter is generally 5cm smaller than the larger wheel rim.When hemiplegia is driven by one hand, add another one with a smaller diameter for selection.The wheel rim is generally pushed directly by the patient. If the function is not good, it can be modified in the following ways to make it easier to drive:
- Add rubber to the surface of the handwheel rim to increase friction.
- Add push knobs around the hand wheel circle
- Push Knob horizontally. Used for C5 spinal injuries. At this time, the biceps brachii are strong, the hands are placed on the push knob, and the cart can be pushed forward by bending the elbows. If there is no horizontal push knob, it cannot be pushed.
- vertical push knob.It is used when there is limited movement of shoulder and hand joints due to rheumatoid arthritis.Because the horizontal push knob cannot be used at this time.
- Bold push knob.It is used for patients whose finger movements are severely limited and it is difficult to make a fist. It is also suitable for patients with osteoarthritis, heart disease or elderly patients.
Tires: There are three types: solid, inflatable, inner tube and tubeless.The solid type runs faster on flat ground and is not easy to explode and is easy to push, but it vibrates greatly on uneven roads and is difficult to pull out when stuck in a groove as wide as the tire;Inflatable inner tires are harder to push and easier to puncture, but vibrate more than solid tires small;The tubeless inflatable type is comfortable to sit on because the tubeless tube will not puncture and is also inflated inside, but it is more difficult to push than the solid type.
Brakes: Large wheels should have brakes on each wheel.Of course, when a hemiplegic person can only use one hand, he has to use one hand to brake, but you can also install an extension rod to operate the brakes on both sides.
There are two types of brakes:
Notch brake. This brake is safe and reliable, but more laborious. After adjustment, it can be braked on slopes. If it is adjusted to level 1 and cannot be braked on flat ground, it is invalid.
Toggle brake.Using the lever principle, it brakes through several joints,Its mechanical advantages are stronger than notch brakes, but they fail faster.In order to increase the patient’s braking force, an extension rod is often added to the brake. However, this rod is easily damaged and may affect safety if not checked regularly.
Seat:The height, depth, and width depend on the patient’s body shape, and the material texture also depends on the disease. Generally, the depth is 41,43cm, the width is 40,46cm, and the height is 45,50cm.
Seat cushion:To avoid pressure sores, pay close attention to your pads. If possible, use eggcrate or Roto pads, which are made from a large piece of plastic.It is composed of a large number of papillary plastic hollow columns with a diameter of about 5cm. Each column is soft and easy to move. After the patient sits on it, the pressure surface becomes a large number of pressure points.Moreover, if the patient moves slightly, the pressure point will change with the movement of the nipple, so that the pressure point can be continuously changed to avoid pressure ulcers caused by frequent pressure on the affected area.If there is no cushion above, you need to use layered foam, whose thickness should be 10cm. The upper layer should be 0.5cm thick high-density polychloroformate foam, and the lower layer should be medium-density plastic of the same nature.High-density ones are supportive, while medium-density ones are soft and comfortable.When sitting, the pressure on the ischial tubercle is very large, often exceeding 1-16 times the normal capillary short pressure, which is prone to ischemia and formation of pressure ulcers.In order to avoid heavy pressure here, often dig out a piece on the corresponding pad to allow the ischial structure to be elevated. When digging, the front should be 2.5cm in front of the ischial tubercle, and the side should be 2.5cm outside the ischial tubercle. The depth At around 7.5cm, the pad will appear concave-shaped after digging, with the notch at the mouth. If the above-mentioned pad is used with an incision, it can be quite effective in preventing the occurrence of pressure ulcers.
Foot and leg rests:The leg rest can be either a cross-side type or a two-side split type. For both of these types of support, it is ideal to use one that can swing to one side and be detachable.Attention must be paid to the height of the foot rest.If the foot support is too high, the hip flexion angle will be too large, and more weight will be placed on the ischial tuberosity, which can easily cause pressure ulcers there.
Backrest:The backrest is divided into high and low, tiltable and non-tiltable. If the patient has good balance and control over the trunk, a wheelchair with a low backrest can be used to allow the patient to have a greater range of motion. Otherwise, choose a high-back wheelchair.
Armrests or hip supports:It is generally 22.5-25cm higher than the chair seat surface, and some hip supports can adjust the height. You can also put a lap board on the hip support for reading and dining.
Choice of wheelchair
The most important consideration when choosing a wheelchair is the size of the wheelchair.The main areas where wheelchair users bear weight are around the ischial tuberosity of the buttocks, around the femur and around the scapula.The size of the wheelchair, especially the width of the seat, the depth of the seat, the height of the backrest, and whether the distance from the footrest to the seat cushion is appropriate, will affect the blood circulation of the seat where the rider puts pressure, and may lead to skin abrasion and even pressure sores.In addition, the patient’s safety, operating ability, weight of the wheelchair, location of use, appearance and other issues must also be considered.
Issues to note when choosing:
Seat width:Measure the distance between the buttocks or the crotch when sitting down. Add 5cm, that is, there will be a 2.5cm gap on both sides after sitting down.The seat is too narrow, making it difficult to get in and out of the wheelchair, and the buttocks and thigh tissues are compressed;If the seat is too wide, it will be difficult to sit firmly, it will be inconvenient to maneuver the wheelchair, your limbs will get tired easily, and it will be difficult to get in and out of the door.
Seat length:Measure the horizontal distance from the back hip to the gastrocnemius muscle of the calf when sitting down.Subtract 6.5cm from the measurement.If the seat is too short, the weight will mainly fall on the ischium, which may cause excessive pressure on the local area;If the seat is too long, it will compress the popliteal fossa, affect local blood circulation, and easily irritate the skin in this area.For patients with short thighs or patients with hip or knee flexion contractures, it is better to use a short seat.
Seat height:Measure the distance from the heel (or heel) to the popliteal fossa when sitting down, and add 4cm. When placing the footrest, the board should be at least 5cm from the ground. If the seat is too high, the wheelchair cannot enter the table; if the seat is too low, The sit bones bear too much weight.
Cushion:For comfort and to prevent bedsores, cushions should be placed on the seats of wheelchairs.Common seat cushions include foam rubber cushions (5-10 cm thick) or gel cushions. To prevent the seat from collapsing, a 0.6 cm thick plywood can be placed under the seat cushion.
Seat back height: The higher the seat back, the more stable it is,the lower the back, the greater the movement of the upper body and upper limbs.
Low backrest:Measure the distance from the sitting surface to the armpit (with one or both arms stretched forward), and subtract 10cm from this result.
High seat back: Measure the actual height from the sitting surface to the shoulders or backrest.
Armrest height:When sitting down, with your upper arms vertical and your forearms flat on the armrests, measure the height from the chair surface to the lower edge of your forearms, add 2.5cm.Proper armrest height helps maintain correct body posture and balance and allows the upper body to be placed in a comfortable position.The armrests are too high and the upper arms are forced to rise, making them prone to fatigue. If the armrest is too low, you will need to lean your upper body forward to maintain balance, which is not only prone to fatigue but can also affect breathing.
Other accessories for wheelchairs:It is designed to meet the needs of special patients, such as increasing the friction surface of the handle, extending the carriage, anti-shock devices, installing hip supports on the armrests, or wheelchair tables to facilitate patients to eat and write, etc.
Wheelchair maintenance
Before using the wheelchair and within one month, check whether the bolts are loose. If they are loose, tighten them in time.In normal use, conduct inspections every three months to ensure that all components are in good condition. Check the various strong nuts on the wheelchair (especially the fixed nuts of the rear wheel axle). If they are found to be loose, they need to be adjusted and tightened in time.
If the wheelchair encounters rain during use, it should be wiped dry in time. Wheelchairs in normal use should also be wiped regularly with a soft dry cloth and coated with anti-rust wax to keep the wheelchair bright and beautiful for a long time.
Frequently check movement, flexibility of the rotating mechanism, and apply lubricant. If for some reason the axle of the 24-inch wheel needs to be removed, make sure the nut is tightened and not loose when reinstalling.
The connecting bolts of the wheelchair seat frame are loose and must not be tightened.
Classification of wheelchairs
General wheelchair
As the name suggests, it is a wheelchair sold by general medical equipment stores. It is roughly the shape of a chair. It has four wheels, the rear wheel is larger, and a hand push wheel is added. The brake is also added to the rear wheel. The front wheel is smaller, used for steering. Wheelchair I’ll add an-tipper at the back.
Generally, wheelchairs are relatively lightweight and can be folded and stowed away.
It is suitable for people with general conditions or short-term mobility difficulties. It is not suitable for sitting for long periods of time.
In terms of materials, it can also be divided into: iron pipe baking (weight 40-50 kilograms), steel pipe electroplating (weight 40-50 kilograms), aluminum alloy (weight 20-30 kilograms), aerospace aluminum alloy (weight 15 -30 catties), aluminum-magnesium alloy (weight between 15-30 catties)
Special wheelchair
Depending on the patient’s condition, there are many different accessories, such as reinforced load capacity, special seat cushions or backrests, neck support systems, adjustable legs, removable dining tables and more.
Since it is called special-made, the price is of course very different. In terms of use, it is also troublesome because of the many accessories. It is usually used for people with severe or severe limb or torso deformation.
Electric wheelchair
It’s a wheelchair with an electric motor
Depending on the control method, there are rockers, heads, blowing and suction systems, and other types of switches.
For those who are ultimately severely paralyzed or need to move a larger distance, as long as their cognitive ability is good, using an electric wheelchair is a good choice, but it requires a larger space for movement.
Special (sports) wheelchairs
A specially designed wheelchair used for recreational sports or competition.
Common ones include racing or basketball, and those used for dancing are also very common.
Generally speaking, lightweight and durability are the characteristics, and many high-tech materials are used.
Scope of use and characteristics of various wheelchairs
There are many types of wheelchairs on the market at present. They can be divided into aluminum alloys, light materials and steel according to materials. For example, they can be divided into ordinary wheelchairs and special wheelchairs according to type.Special wheelchairs can be divided into: leisure sports wheelchair series, electronic wheelchair series, seat-side wheelchair system, etc.
Ordinary wheelchair
Mainly composed of wheelchair frame, wheels, brakes and other devices
Scope of application:
People with lower limb disabilities, hemiplegia, paraplegia below the chest and the elderly with limited mobility
Features:
- Patients can operate fixed or removable armrests themselves
- Fixed or removable footrest
- Can be folded for carrying when going out or when not in use
According to different models and prices, they are divided into:
Hard seat, soft seat, pneumatic tires or solid tires.Among them: wheelchairs with fixed armrests and fixed foot pedals are cheaper.
Special wheelchair
The main reason is that it has relatively complete functions. It is not only a mobility tool for disabled people and people with limited mobility, but also has other functions.
Scope of application:
High paraplegics and the elderly, frail and sick
Features:
- The backrest of the walking wheelchair is as high as the rider’s head, with removable armrests and twist-type foot pedals. The pedals can be raised and lowered and rotated 90 degrees, and the bracket can be adjusted to a horizontal position.
- The angle of the backrest can be adjusted in sections or continuously to any level (equivalent to a bed). The user can rest in a wheelchair, and the headrest can also be removed.
Electric wheelchair
Scope of application:
For use by people with high paraplegia or hemiplegia who have the ability to control with one hand.
The electric wheelchair is powered by a battery and has a endurance of about 20 kilometers on a single charge. Does it have a one-hand control device.It can move forward, backward and turn. It can be used indoors and outdoors. The price is relatively high.
Post time: Dec-09-2024