A prosthetic leg knee works by mimicking the natural knee joint's function, allowing for controlled bending and straightening during walking and other activities, and often automatically adjusts to the user's walking style.
The complexity of a prosthetic knee varies depending on the type and its intended use. Here's a breakdown of how they generally work:
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Mechanical Knees: These are the simplest types. They rely on mechanical hinges and linkages to provide stability and movement.
- Single-Axis Knees: These have a single pivot point, similar to a simple door hinge. They are durable and straightforward but offer limited control.
- Polycentric Knees: These have multiple pivot points, providing more stability and a more natural gait. The multiple axes help to shorten the leg during swing phase, increasing ground clearance.
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Microprocessor-Controlled Knees: These are advanced knees equipped with sensors and microprocessors that analyze the user's gait in real-time.
- Sensors: Detect angle, speed, and load.
- Microprocessor: Processes sensor data to control hydraulic or pneumatic cylinders within the knee.
- Hydraulic/Pneumatic Cylinders: Adjust resistance to control the knee's flexion and extension, adapting to different walking speeds and terrains.
- Automatic Adjustment: The knee can adapt to the individual's walking style over time, learning and adjusting to their movements.
The excerpt provided mentions adjustability and automatic adaptation: "So it's very adjustable. As a person starts to learn how to walk better it auto adapts to how they're walking." This refers to the ability to fine-tune the prosthetic knee and its capacity to learn and respond to the user's movements.
In summary, prosthetic knees work by using either mechanical linkages or advanced microprocessor-controlled systems to simulate the natural movement of the knee joint. These knees allow amputees to walk, run, and perform other activities with greater ease and control.
