Suspension
WillowWood offers several suspension options that help keep your residual limb secure. What’s the right option for you? Read the sections below to find out.
NOTE: Always contact your clinician for prosthetic care advice. The following descriptions are available to help you get started in choosing which option may be best suited for you, but should never replace prosthetic advice from your clinician.
What works best for one amputee might not be what works best for another. Here are some of the pros and cons of each method:
Locking Pin Suspension
Locking pin suspension, in which a pin on the bottom of the liner fits into a lock in the bottom of the socket, gives many amputees the feeling of a secure suspension. It is also generally the easiest of these three methods to don and doff. The main disadvantage is “pistoning,” which is when the liner and limb stretch out within the socket while the leg is swinging forward due to daily volume fluctuation. Additionally, the pin must be centered exactly within the lock, which can be hard for amputees who have poor eyesight.
Suction Suspension
Suction suspension holds the limb secure because air in the socket is forced out through a valve at the bottom of the socket, creating a vacuum effect. Pistoning is not an issue, because the weight of the prosthesis is not focused on one small point at the bottom of the socket. Further, there’s no need to line up a pin with a lock. However, a suspension sleeve is required to prevent air from entering the socket, which adds a little weight and bulk.
Electronic Elevated Vacuum
Elevated vacuum systems, which are electronic, need to be charged daily and provide outstanding security and reliability. Like suction suspension, elevated vacuum sometimes referred to as active vacuum, uses a difference in atmospheric pressure to attach the socket to the residual limb. But because suction suspension uses a passive expulsion valve to allow air to leave the socket, a negative pressure differential is only created when the limb begins to move. The active pump used in vacuum suspension doesn’t depend upon the limb position.
Mechanical Elevated Vacuum
Mechanical elevated vacuum systems operate similarly to electronic systems, but do not need to be charged. It’s an ideal option for amputees who prefer a low-maintenance, easy-to-use system without comprising reliable security. Mechanical systems are simple to set up and may allow some adjustability. Only the LimbLogic M allows clinicians to adjust both vacuum and stiffness settings.
Caring for your LimbLogic®:
Your pump, fob, and charger are unlikely to be damaged by exposure to lint, dust, or light. However, it is best not to charge the pump while it is sitting in direct sunlight or near a furnace. This might heat the pump enough to prevent it from obtaining a full charge.
- You can clean your pump by wiping it with a damp cloth. Use only water.
- Do not allow children or pets to play with your LimbLogic® or its accessories. They are designed to be durable, but they may be damaged if exposed to rough handling such as chewing.
- You may place the vacuum pump in 10 feet (3 meters) of freshwater for up to 12 hours. Do not submerse the vacuum pump in salt water. Do not submerse the vacuum pump in corrosive liquids. Be sure to dry off the vacuum pump if it is exposed to rain or other moisture. The fob and charger should not be exposed to water or other liquids. If your fob is damaged by water, call your prosthetist for a replacement.
How to care for your One System
Please refer to the care information for LimbLogic® (above) and Alpha® Liner.
What do I do if I notice a leak in my One System?
- Check to see if there is a hole in the One Seal/Sleeve or if the fins on the One Seal/Sleeve are torn. If so, contact your prosthetist.
- Check to see if the sealing surface between the liner and the One Seal/Sleeve is too small. Make sure the One Seal/Sleeve is positioned as shown in the instructions you received with your system.
- Check to see if the o-ring on the expulsion valve is damaged or if any of the screws holding the pump to the socket are missing. If so, contact your prosthetist.
What should I do with my prosthesis when I’m not wearing it?
When the prosthesis is not being worn, the bottom portion of the sleeve should be left on the socket. The top half of the sleeve should be unrolled and allowed to drape into the socket for protection. Allowing the sleeve to extend out of the socket is also acceptable. Do not leave the top half of the sleeve rolled back onto the socket edge.
