Manual wheelchair is generally composed of pusher, wheelchair frame, wheel, brake device, anti-backward device, seat and pedal.
1. Big Wheels
It bears the main weight. The diameters of wheels are 51, 56, 61 and 66 cm. Pneumatic tires are commonly used except for a few solid tires which are required by the environment.
2. Small Wheels
There are 12, 15, 18 and 20 cm in diameter. Small wheels with large diameter are easy to cross small obstacles and special carpets. But the big diameter makes the space occupied by the wheelchair larger and the movement inconvenient. Normal wheels are in front of big wheels, but wheelchairs for paraplegics of lower limbs often put small wheels behind big wheels. In operation, it should be noted that the direction of the small wheel is best perpendicular to that of the large wheel, otherwise it is easy to topple.
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3. Handwheel Ring
It is unique to wheelchairs, and its diameter is generally 5 cm smaller than that of large wheelchairs. When hemiplegia is driven by one hand, a smaller diameter is added for selection. Handwheel rings are usually driven directly by patients. If the function is not good, they can be easily driven by the following ways:
(1) Rubber is added to the surface of the handwheel ring to increase the rubbing force.
(2) Increase the knob around the handwheel ring.
There are several kinds of push handles:
Horizontal push bar. For C5 spinal injury. Therefore, the biceps brachii muscle is sound, the hand is on the pusher, and the pusher can move forward by bending the elbow force. If there is no horizontal push, it can not be pushed.
(2) Vertical push handle. For rheumatoid arthritis when shoulder-hand joint movement is limited. Therefore, the horizontal push can not be used.
Thicker push handle. It is also suitable for patients with osteoarthritis, heart disease or senile patients who are severely restricted in finger movement and are not easy to clench their fists.
4. Tyres
There are solid, inflatable inner tube and inflatable inner tube. Solid type walks faster on flat ground and is not easy to blast and push, but it vibrates heavily on uneven road and is not easy to pull out when it is stuck in the ditch of the same width as the tire; inflatable inner tube is more difficult to push and puncture, but its vibration is smaller than solid inner tube; inflatable inner tube without inner tube will not puncture, and it is also inflatable and comfortable to sit up, but it is better than solid inner tube. Solid people are harder to push.
5. Brake
Big wheels should have brakes on each wheel. Of course, if a hemiplegic can only use one hand, he has to use one hand to brake, but he can also install extension rods to control the brakes on both sides.
There are two kinds of brakes:
(1) Concave brake. This brake is safe and reliable, but more laborious. After adjustment, it can also brake on the slope. If it can't be braked on the flat ground, it will be invalid.
(2) Elbow brake. By using the lever principle and braking after several joints, its mechanical advantages are stronger than the concave brake, but its failure is faster. In order to increase the braking force of patients, an extension rod is often added to the brake, but the rod is easy to be damaged. If not checked frequently, it will affect the safety.
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