Prosthetic limb selection is not multi-functional, expensive, suitable for their own is the best

Compared with traditional prostheses, modern prostheses have the advantages of light weight, multiple functions, strong compensatory capabilities, and easy popularization in factory production. They have become indispensable life partners for the majority of amputee patients. However, due to the wide variety of modern prosthetic products with widely different functions, coupled with the recommendations of some so-called marketers, which are both good and bad, amputee patients are at a loss when choosing prosthetic products.

The selection of prosthetic products should be based on the patient's physical constitution, residual limb condition, individual personality, professional habits, athletic ability, use environment and economic status, etc., and be scientifically selected and determined after evaluation by rehabilitation physicians and rehabilitation engineers.

Compensation capacity of lower limb prostheses

It can basically meet the requirements of daily life

Lower limb prostheses refer to prostheses installed at every part of the limb from below the pelvis to above the toe joint. The purpose of installing lower limb prostheses is to compensate for lower limb deficiencies and replace human body support and walking functions. The basic structure of lower limb prostheses is composed of prosthetic feet, joints, integrated connecting tubes, etc., and a socket that can accommodate the residual limb and transmit force.

Depending on the amputation site, lower limb prostheses include hip disarticulation prostheses, thigh prostheses, knee disarticulation prostheses, calf prostheses, Syme prostheses, Schobert prostheses, etc. Generally, the higher the amputation site, the higher the functional and installation technical requirements for the prosthesis.

Most modern lower limb prostheses are skeletal prostheses, which are connected by many standard components. This is not only conducive to factory production and promotion, but also effectively promotes technological innovation in prosthetic products.

Especially with the advancement of material technology and the widespread application of lightweight, high-strength, and high-elastic materials such as titanium alloy and carbon fiber, prosthetic products have made a qualitative leap in quality and function, and humanized selection can be made to quickly customize lower limb prosthetic products with different requirements. The compensatory capabilities of lower limb prosthetic products can basically meet the daily life requirements of amputee patients.

However, at present, lower limb prostheses are basically unpowered prostheses, that is, the swing of the lower limb residual limb and the body is used as the power source to drive the movement of the prosthesis, which means that the prosthesis itself has no power. Although the support phase can provide sufficient stability, the swing phase is not satisfactory, especially for prosthetic products above the knee disconnection. Although air pressure and hydraulic pressure have been developed to assist knee joint extension, walking still consumes a lot of energy, the walking speed cannot be adjusted at will, and there is still a lot of room for improvement in gait.

At present, smart prosthetics and powered legs have been developed abroad, but due to high prices and maintenance problems, they are still far away from ordinary residents.

Choose the right prosthesis, not the expensive one

Some amputee patients often complain that the prosthetic products they have installed are not ideal during use, and they can easily fall if they are not careful. Some people are dissatisfied with their gait, and some even complain that the prosthetic limbs cause trouble for them.

The selection of lower limb prostheses should be based on your age, physical condition, residual limb condition, use environment, athletic ability, etc., and based on the evaluation of rehabilitation physicians and rehabilitation engineers. Choosing a prosthetic limb is not about having more functions or being more expensive, but the one that suits you is right.

Clinically, many amputee patients who have just regained their confidence always want to install a prosthetic limb with the most functions and the best. Prosthetic limb company marketers will blindly cater to patients and recommend the latest and most expensive prosthetic limbs. But in fact, even the most versatile and powerful prosthetic limb may not be suitable for every amputation patient.

Human walking can be divided into a support phase and a swing phase from the time when the heel strikes the ground to when the heel on the same side touches the ground again. The same goes for lower limb prostheses. The support phase must be stable enough and able to adapt to various road surfaces, while the swing phase must be easy, flexible, and controllable at will, so as to ensure easy, safe walking and good gait.

At present, although lower limb prostheses have been developed with various functions such as energy storage, shock absorption and buffering, pneumatic (hydraulic) extension control, knee bending, gyration and other functions, as well as bionic intelligent prostheses and powered legs, the "Blade Warrior" can even compete with able-bodied people on the field, but mature technology that can be controlled at will has not yet been developed. The choice of prosthetic limbs should respect daily life and make a trade-off between safety and flexibility.

For patients with lower leg amputations, such as those who are older, in poor physical condition, have short residual limbs, or live in mountainous areas, they should choose calf prostheses that move the ankle or have lower exercise levels. This type of prosthetic limb has strong adaptability to the road surface, high safety and easy control. Young and middle-aged patients and patients with good residual limb conditions can choose calf prostheses with high energy storage and high movement level, which will help them return to work and participate in labor, and their gait is also very ideal.

Patients with amputations above the knee, such as those who are older, in poor physical condition, have short residual limbs, or live in mountainous areas, should choose multi-axis knee joints or even knee joint lockable prostheses. When choosing prostheses, flexibility and gait must be emphasized on the basis of safety, otherwise it will cause a lot of trouble in use.

As for patients with better economic conditions, pneumatic (hydraulic) pressure assist extension control, superior bionic and bionic intelligent prostheses can be considered. Even bionic smart prostheses can only exert their functional advantages when walking on flat roads and steps.

Socket manufacturing technology

It is very critical in the installation of prosthetic limbs

The prosthetic socket is an important mediator that connects the residual limb and prosthetic limb components. It can accommodate the residual limb and play the role of carrying the body weight, transmitting force, and controlling the prosthetic limb.

The prosthetic socket must conform to anatomy and biomechanics, must be comfortable during use, and is responsible for the function of force transmission and movement transmission. The design and production of the socket is a very critical link in the installation of prosthetic limbs.

Amputee patients who have worn prosthetic limbs all know that the residual limb is affected by various unavoidable forces such as rotation, friction, torsion, and impact in the socket. In addition, the residual limb has many unbearable bony protrusions and irregular shapes, sensitive skin, surgical scars and other factors. Some are even severely deformed and affect the alignment of the prosthetic limb. These should be carefully considered and solved in the design and production of the prosthetic socket.

Most of the current prosthetic sockets use full-contact sockets. Compared with the traditional plug-in type, there has been significant technological progress, such as the thigh socket, from the plug-in socket to the quadrilateral ischial load-bearing socket to the ischium-containing and ischial branch-containing sockets. In particular, the application of lining materials such as silicone has effectively solved the ineffective forces inside the socket and improved the force transmission performance and comfort of the socket.

Prostheses are not commodities but products. Please choose to install them at an experienced rehabilitation service institution to ensure product quality, installation and production quality, and follow-up services.

(Original title: Choosing a prosthetic limb is not about having multiple functions or being expensive, but just the one that suits you is the best)

Interviewed: Yang Xuemin, Director of the Bone, Joint and Spinal Cord Injury Rehabilitation Department of Ningbo Rehabilitation Hospital

Pictured: Photographed at a prosthetic limbs exhibition