Lower Limb Prosthetic Devices

• Single-Axis

  • Similar to hinge mechanisms

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• Multi-Axis or Polycentric or Four-Bar

  • Variations can be set up for different phases

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• Sliding friction prevents the leg from swinging too fast

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• Most include the ability to lock the knee in place

  • Manual Locking or Weight-Activated Locking)

• Solid Ankle Cushion Heel

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• More rigid

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• Sufficient shock absorption

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• Optimal for light activity

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• Resisted movement of the foot at an adjustable hydraulic ankle joint

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• Allows for more natural “rocking” motion during walking

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• Allows for walking with greater stability

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• Reduces pressure in the socket and increases stability

• Fluid (hydraulic) or air (pneumatic) is used to control the knee movement

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• Stance control – allows the user to lock the knee for stability while standing

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• Mimic muscles of the natural knee allowing for variable walking speeds

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• Store and release energy

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• Mimic normal ankle motion

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• Single-Axis

  • Solid forefoot, moves in 1 plane (up and down)

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• Multiple-Axis

  • Moves in multiple planes (up and down, side to side)

  • Absorbs torque

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• Type of hydraulic ankle/feet

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• Uses various sensors to monitor continuous movement

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• Adjusts both the angle and stiffness of ankle in real-time

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• Better ankle movement and foot control on uneven terrain, inclines, declines, and stairs

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• Also known as a computer-controlled knee or Microprocessor-Controlled (MCP)

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• Automatically adjusts the response of the knee in real-time

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• Sensors gather movement and timing data

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• Energy-storing – store and release energy with every step

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• Increases ability to walk at varying speeds while reducing the load on the opposite leg

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• Designed for specific tasks and activities

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• Maybe be water proof/resistant or able to withstand higher loads and stresses

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• Examples include feet specific for swimming, running, skiing, climbing, etc.

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