Some patients visited the prosthetic company. The technicians of the prosthetic company talked about a lot of professional terms, but they didn't remember a few of them. After listening to them, they were confused when choosing the thigh prosthesis. When choosing the prosthesis, they still had to rely on the recommendation of the prosthetic company. Prosthesis is is not a fast-selling product. There will be a long after-sales service. Generally, a better prosthesis can be used for five years or even more. Therefore, it is necessary to be careful when choosing a prosthetic. You must choose a reliable prosthetic company, because in the next ten years or more, you will have to deal with this prosthetic company.

How to choose a suitable prosthesis leg in china? How to know what kind of prosthesis is more suitable for you? Let's introduce some professional words.

EBS elastic shock absorption knee flexion insurance:

According to the characteristics of human biomechanics, the heel has 15 degree flexion insurance when landing. The impact of the ground surface on the prosthetic side is reduced, and the gait is closer to the natural gait. More importantly, when going down the slope, due to the 15 degree flexion angle of the EBS of the knee joint, the user feels that the center of gravity moves backward, and the downhill slope is safer.

Difference between ball bearing and needle roller bearing:

The biggest difference between the two kinds of bearings is the difference in load. The ball contact is point contact, which is used in light load, and the needle roller is in line contact, which has large bearing capacity and better durability. Moreover, the inner or outer ring can be separated, which is more convenient for installation and disassembly.

External cylinder block and internal cylinder block:

The power system of artificial limb, thigh and knee joint is usually pneumatic or hydraulic. When the knee joint is moving, its pneumatic or hydraulic cylinder block is doing piston movement. If the time is slightly longer, it will generate heat. Because the cylinder block is wrapped by the load-bearing shell, the heat dissipation is poor. Especially for young people with large amount of activity, the service life of knee joint with built-in cylinder is much less than that of knee joint with external cylinder block.

High power cylinder block and low power cylinder block:

The higher the power, the stronger the explosive force, the wider the adjustment range of flexion and extension damping, the more natural the gait adjustment. Moreover, the powerful power provided by high power makes the movement and walking more labor-saving. Among the knee joints sold on the market, many knee joints with high power pneumatic cylinder block are better than those with low-power hydraulic cylinder block.

Single axis knee joint:

As the name suggests, it is a prosthetic knee joint with a single axis of rotation. Its advantage is that it has high flexibility in the swing period, and the corresponding disadvantage is that the support period is not stable enough. It is more suitable for young patients with large amount of activity, long residual limb and good control ability, so as to achieve higher functional requirements. This is also the reason why the knee joint is generally used as a single axis.

Multi axial knee joint:

The rotation center of normal human knee joint will move with flexion and extension. For single axis knee joint, the rotation center of lower leg will not move. The multi axis knee joint is mostly designed by connecting rod. When the knee joint rotates, the center moves up and down, back and forth with the knee joint flexion and extension angle (the longer the link, the greater the range of motion). In this way, the change of leg length at the initial stage of support can reduce the hip joint extension muscle strength required to stabilize the knee joint (leg lifting can save more effort). On the other hand, in the middle of swing or when sitting on a chair, the knee axis height drops to the normal position, and there is no appearance problem. The advantages of multi axis design are that the leg lifting is more labor-saving, the gait is softer and the safety is better; the disadvantage is that the flexibility is not as good as that of single axis.

Front center of gravity:

A normal person in the process of walking, to the stage of single leg support, quadriceps femoris tight, hip muscles start to contract, the body's center of gravity will move forward. The center of gravity front joint prosthesis is to imitate the state that the center of gravity moves forward during the support period of single leg, which makes the prosthetic limb safer in the process of walking.

Load bearing self-locking:

Earlier technology, the role of load-bearing self-locking joint is that, in the process of walking, the legs alternately bear the weight. When the artificial limb is loaded, it can be locked, so that the joint can not bend. In this way, it can ensure the safety of the prosthetic limb in the walking state, which is safer than the prosthetic limb with the center of gravity in front. Now we have improved the bionic induction lock in the load-bearing self-locking technology, and the safety and functionality have been improved by a level.

Bionic geometric lock:

Also known as the upright self-locking knee joint, this design enables the patient to maintain stability when the heel touches the ground, which better mimics the function of the human knee joint. This kind of joint will be locked automatically after the end of the swing period and the knee joint is fully straightened, and the joint locking will be automatically released after the end of the support period. It has the characteristics of automatic locking in the support period and flexing the knee freely in the swing period, and the safety is better than the load-bearing self-locking.

Bionic induction lock:

A kind of safety knee lock developed on the basis of load-bearing self-locking can be locked at any angle through the control of the residual limb. It provides better comfort and safety protection for those who need to maintain a talent for a long time (such as barbers, rowers, etc., who have to work long hours with bent legs).