Published 2/04, Copyright 2004, WheelchairJunkie.com

A WheelchairJunkie's Guide to Legrests
By Mark E. Smith

Are your feet sliding or your legs swinging as you go about your daily business?  While these symptoms certainly could describe one possessed by the latest dance craze, if you're a wheelchair user, it's more likely a sign of improper or poorly-adjusted legrests.  An incorrect legrest angle or inappropriate length can lead to problems ranging from hampered maneuverability to unbearable discomfort - to legs that simply won't stay in place.  Fortunately, legrests are among the most adaptable components on wheelchairs, and proper fit and function is often an adjustment or component away.

Legrest Angle
If you've read a wheelchair order form, you've seen legrests designated by 60-, 70-, 80-, or 90-degree options.  This specification refers to the angle at which the legrests slope away from the chair.  Put simply, the lower the number, the less your legs are bent, and the farther out the legrests extend from the chair (for example, a 60-degree legrests will place your feet in a position similar to sitting in a car, with your feet ahead of you, whereas 90-degree legrests will place you in a position similar to sitting in a kitchen chair, with your feet straight down).

Legrest angle is especially vital for those with muscular or circulatory conditions within their legs.  A user with cerebral palsy, for example, may have a contracted leg position, needing a 90-degree legrest for proper support.  To the contrary, someone with circulatory concerns may need a more open leg, dictating a 60-degree legrest.  Along these lines, doctors and therapists often prescribe a set thigh-to-calf (or, knee), angle.  It's important to note that while the leg angle is a direct compliment to the legrest angle, the points of measurement differ, resulting in a 110-degree leg angle matching a 70-degree legrest angle - put simply, if the doctor prescribes a 110-degree leg angle position, that's not the number to look for on the legrest order form.  

The equation to convert your leg angle to a legrest angle is as follows:
A = 180-degrees
X = Leg Angle
Y = Legrest Angle
Equation: A - X = Y  (or, 180-degrees - Leg angle = Legrest Angle)

Beyond positioning and comfort, legrest angle also plays a role in the overall length of your wheelchair.  Depending on legrest design, a chair may be as much as 2" shorter with 80-degree legrests than 70-degree legrests (however, it's important to note that depending on a particular type of chair, not all legrest angles may be available, and comfort and condition must always balance with performance - that is, shorter isn't always better).  In general, the vast majority of wheelchairs today feature 70-degree legrests as standard, with other angles optional.

Legrest Length
Based on the measurement from your knee to heal, legrest length contributes to proper positioning and pressure management.  Too short of legrests my place your knees too high, rotating your pelvis, with consequences toward your spine and dramatically increasing seating pressure points.  To the other extreme, too long of legrests can place extraordinary pressure on the undersides of the upper legs, restricting circulation.  Yet, a proper legrest length solves both these issues, encouraging healthy posture and circulation.  

The industry standard for adjustable legrest lengths is 14" to 17", with options for shorter or taller users.  It's important to note, however, that legrest length is measured from the seat plane to the footplate, so if you use a cushion, don't forget that it will raise the seat plane accordingly, so a 14" legrest length with the addition of a 4" cushion becomes an 18" overall legrest length.    

The easiest way to measure your needs for legrest length is to use your existing chair as a model, presuming it's fitted correctly.  However, another consumer equation, if there're no complex conditions, is to measure from the underside of your knee to your shoe heel, then subtract 1".  Then, compare your leg measurement to the legrest length plus the cushion height combined to approximate fit (this is useful when selecting among adjustable length packages).

Legrest Styles
Swing-away legrests are among the most common legrests on powerchairs and folding manual chairs.  To swing away the legrests, you release a latch, and they swing out to the side of the chair (or, if they're bi-directional, they also swing inward, under the seat for clearance when parked beside a bed, for example).  Traditionally, pin-style mounts were used, requiring the alignment of two small holes and pins when installing they legrests - and they're still the industry standard on K0004 manual chairs.  However, drop-in legrests are the most common on powerchairs and K0005 ultralightweight manual chairs.  To mount drop-in legrests, you align a single post with a large receiver socket, and drop the legrest into place.  Some drop-ins use a swing-away latch, while others are keyed, requiring that you lift up the legrest to swing it to the side.  All in all, drop-ins are the way to go for those with limited dexterity.

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On powerchairs, flip-up foot platforms are among the most durable and reliable form of leg support, with stout anchoring to the chair.  For transfers, the platform flips up against the front of the chair, but depending on the model, may still protrude by a few inches.  Most foot platforms are height-, angle-, and depth-adjustable, but because they're of a single plate, usually aren't as adaptable as swing-aways for higher-end needs (though, platforms are showing up on rehab seating systems like those by Motion Concepts and Quantum Rehab).

Rigid foot platforms are traditional on rigid ultralights, featuring a foot "basket" that's fixed in place, with the only adjustment relating to height.  On manual chairs - and more recently on some powerchairs - rigid foot platforms are all but indestructible, and enhance a chair's rigidity, but don't swing-away or flip-up for transfers.  On performance rigid manual chairs, a rigid foot platform is the top choice; however, a rigid foot platform may be too restrictive for many powerchair users.

Footplate Options
Flip-up footplates - common in composite or aluminum - are standard on swing-aways.  Footplates are usually the weakest point of a legrest, and under the most stress, with your feet pressing and bouncing on them, making them a vital area to consider.  If you're especially hard on footplates, you may wish to move into heavy-duty versions, which are reinforced, and often feature an adjustment to compensate for downward sag.

Angle-adjustable footplates allow you to adjust the for-aft horizontal angle of the footplate, conforming to your calf and ankle needs.  An effective footplate distributes weight evenly across the foot, so for someone whose foot has an involved anterior or posterior position, an angle-adjustable footplate allows adapted support.  Additionally, for those with exceptional needs, bi-axial footplates allow angle adjustability in four directions, heal to toe, and right to left tilts.  Many angle-adjustable footplates are also depth-adjustable, allowing enhanced leg angle positioning.

Elevating Legrests (ELRs)
Elevating legrest travel from an average legrest position of, say, 70-degrees, up to level with the seat plane, and lockable at increments in-between.  For such circulatory issue as edema or knee limitations, ELRs are helpful, and sometimes used in more advanced applications to assist toward overall pressure management.

Articulating and high-pivot ELRs compensate for changes in legrest length as ELRs elevate (on fixed-length ELRs, as they raise, they push the leg back, adding pressure to the knee, whereas articulating and high-pivot ELRs compensate in length, reducing the chance of requiring repositioning of the leg).  For quads, articulating ELRs are especially important, maintaing positioning and reducing knee pressure no matter the ELR angle.

Conclusion
For wheelchair users, proper leg positioning and support are keys to maintained health and enhanced mobility.  From appropriate footplates to swing-away options, the right legrest technologies are the surest way to ensure that the only boppin' your legs do is intentional - that is, on the dance floor.

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