Other base designs include the standard or wide-based quadruped (quad), which features a distal rectangle supporting four tips intended to increase the base of support.⁵⁹ Patients with hemiplegia may not find the four-footed cane any more advantageous than a standard cane with a single tip.⁸⁴ The Pilot rolling cane (available at www.FullLifeProducts.com) has an L-shaped base fitted with three casters that provide the user with the support of a quad cane without the need to lift the cane with each step. The cane also has a brake control in the handle for maximum stability. The Pilot step-up cane has a broad base with a flip-up platform that allows patients to maneuver over curbs and stairs without losing cane support. The user pushes a button on the handle to flip open the hinged platform; this enable the patient to step half the distance of the conventional 8-inch step. With the step retracted, the cane functions as a standard quad cane. The cane also has a second handle part way down the shaft that facilitates rising from toilets and other seats. The side walker/cane (available at www.tfihealthcare.com) has four widely spaced rubber tips that increase stability, especially when used unilaterally by a patient with hemiplegia.

The marketplace also has several novel cane-like designs intended for adults with lower-limb amputation. They enable the user to ambulate without a prosthesis. The Ed Walker (available at www.theedwalker.com) has a bicycle seat mounted on top of a vertical shaft. Jutting laterally is a second curved shaft, which has a platform for the amputation limb and terminates in a cane handle.²⁸ The iWalkFree (available at www.fetterman-crutches.com) has a platform on a vertical shaft that supports the transtibial amputation limb or an injured lower leg. The wearer supports weight through the thigh and knee. Both devices have a stationary base. The Roll-A-Bout (available at www.roll-a-bout.com) terminates in four 8-inch wheels. This folding device has a cushioned platform for the lower leg and a handle that the user holds while propelling with the opposite foot.

A major class of canes is long canes with the lower portion of the shaft colored red. These canes are used by people with visual impairment.^58,^85,^99,¹⁰⁹ The shaft transmits to the user vibratory impulses regarding the terrain, while the red tip signals passersby not to impede the user.

Most patients use a single cane, usually on the side opposite the affected lower limb. However, some people walk with a pair of canes, particularly those who wear bilateral transfemoral prostheses. The cane offers balance or light support as well as sensory feedback from the walking surface.

Crutches

Crutches are of four major types (Figs. 42-2 and 42-3)⁵⁹:

• Underarm

• Triceps

• Forearm (Lofstrand)

• Platform

Fig. 42-2 A, C-handle or crook-top cane. B, Adjustable aluminum cane. C, Functional grip cane. D, Adjustable wide-base quad cane. E, Hemi-walker. F, Adjustable wooden axillary crutch. G, Adjustable aluminum Lofstrand crutch. H, Forearm support or platform support. I, Walker or walkerette.

(From DeLisa DA, editor: Rehabilitation medicine:principles and practice, ed 2, Philadelphia, 1993, JB Lippincott.)

Fig. 42-3 Commonly used crutches and canes.

Underarm crutches, sometimes called axillary crutches, are made of wood, aluminum, and titanium in sizes made to fit children and adults. Metal crutches have spring-loaded detents that facilitate adjustment of hand grip height and overall length. The top of the crutch is erroneously termed the axillary piece. The axilla should never be used as a support area because superficial nerves and blood vessels may be compressed by direct pressure from the axillary piece. The top is often covered with sponge rubber to increase friction and cushion stress against the user’s chest. One design has a top resembling a shepherd’s crook more than twice the length of the basic top; this design offers more support area on the chest. The Easy Strutter Functional Orthosis (available at www.icanwalk.com) has a crutch top that includes, in addition to the underarm piece, a cushioned strap over the shoulder to distribute weight over a broad, pressure tolerant area. The crutch has two parallel struts that terminate in a broad, spring-loaded shock-absorbing base. When three-point gait with axillary crutches was compared with performance with the Easy Strutter Functional Orthosis, the latter crutches imposed less stress on the palms. Subjects reported feeling more secure on level surfaces and stairs with the new crutches.⁹³

The crutch handle should have a resilient cover to cushion compressive stress on the palm. Whether the handle is cylindrical or wide, the palmar load distribution is similar.¹⁰⁷

Although the traditional shaft bifurcates partway up from the base, streamlined single shaft canes are widely available. The usual crutch tip is rubber; however, many cane tips can be used on crutches. The Safe Walk (available at www.sailmarket.com/ticrutch) has two distal shafts both ending with rubber tips; one tip is always on the ground regardless of angle of the crutch. A spring-loaded mechanism at the distal end of the shaft absorbs considerable impact shock.⁹⁶

Triceps (Warm Springs) crutches are made of aluminum. They were developed at the Roosevelt Institute for Rehabilitation (Warm Springs, GA) during the twentieth-century poliomyelitis epidemic. The crutch has two posterior bands intended to keep the elbow extended, mimicking the action of the triceps muscle.

Forearm (Lofstrand) crutches are made of aluminum or titanium with a vinyl-covered steel forearm cuff. They have adjustable length and cuff positions. European model cuffs are streamlined. They are sold in a wide variety of colors and can be ordered in a collapsible model for convenient storage. One innovation is a forearm crutch made of compliant composite plastic with an S curve in the shaft; the crutch design and material contribute to shock absorption.¹¹²

A variation of the rigid cuff is a leather cuff, also known as the Kenny armband. It was named after Sister Kenny, a pioneering clinician who treated patients with poliomyelitis. The armband is less restrictive than the rigid cuff and is used by some people with poliomyelitis and some patients with cerebral palsy.

Platform crutches provide a trough that permits forearm weight bearing for those who cannot tolerate weight transmission through the hand.

Crutches, regardless of design, are ordinarily used in pairs.

Walkers

Walkers are frames that provide bilateral support without the need to control two canes or crutches.

A variety of walkers are manufactured and are described based on their design ⁵⁹:

• Base: Four tips, two tips and two wheels, four wheels, three wheels

• Uprights: Rigid, folding, reciprocating, stair climbing

• Proximal portion: Hand grips, platform

Most walkers are made of aluminum. The simplest model has four legs, each ending in a rubber tip to improve traction. Four-tip walkers provide maximum stability but must be lifted with each step. They are especially appropriate for high-friction surfaces, such as carpet, gravel, and grass. Walker uprights may be height adjustable. The Rising Star SuperWalker (Momentum Medical Corp.) has offset uprights with upper and lower handles that aid the user in rising from a chair. Walkers with wheels can be pushed forward to provide moderate stability; they are more suitable for smooth surfaces, such as linoleum.

Many walkers with two front wheels and two crutch tips are available. The Red Dot walker (available at www.sunrisemedical.com) is a folding walker with two front-swivel 5-inch wheels and rear glide brakes. The Strider group of walkers (available at www.sammonspreston.com) has adjustable wheels and handles. Two-wheeled walkers may have tennis balls or other glides on the rear uprights to smooth ambulation. The WalkAbout has an upper portion that encircles the user.¹³⁵ It also has a built-in seat and a basket. Other walkers with seats include the folding steel Merry Walker (available at www.merrywalker.com), Dura Walker (available at www.duralife-usa.com) made of polyvinylchloride, and the folding steel U-Step (available at www.ustep.com), which has a padded seat, hand brakes, and an optional laser light intended to encourage patients with Parkinson disease to step forward. A walker can have a reciprocating mechanism to accommodate stepping more easily. The Universal Stair Climbing Walker (available at www.tfihealthcare.com) facilitates ascending and descending steps.

Three-wheeled walkers have three angled uprights each ending in a wheel—an example is the Rollator (available at www.sammonspreston.com)—are easier to maneuver in narrow corridors. Basic wheeled and four-tip walkers are manufactured in wide size to suit obese patients.

Adaptations can be made to many walkers. For example, the child with cerebral palsy may walk with better posture using a walker fitted with a hip guard. Direct-forming plastic can be used to make a walker handle more conforming so as to prevent some of the complications in the hand.

Reverse walkers for children with cerebral palsy may facilitate hip and knee extension, allowing them to walk with less energy and a better faster gait. Some walkers for young patients allow hands-free ambulation. These appliances may provide mobility for children who are unable to support the trunk over the pelvis. Examples are the Mulholland Walkabout Gait Trainer (available at www.mulholland.com), Pony walker (available at www.gtkrehab.com.au), Rifton gait trainer (available at www.Rifton.com), and SMART Walker (available at www.llop.com). The SMART walker consists of a trunk–hip–knee–ankle orthosis worn with high-quarter, extra-depth laced-to-toe shoes. The orthosis is attached to a square-wheeled frame that has a steering mechanism designed to reduce neuropathic forces that cause scissoring and internal rotation.

Still under development is a robotic walker, the Veterans Affairs Personal Adaptive Mobility Aid (VA-PAMAID).¹⁰¹ Laboratory testing of the motorized device confirms durability and ease of use by elderly adults and those with visual impairment.

Measuring assistive devices

Whatever the device, the clinician must ensure that it fits properly.^103,^106,¹²⁵ Correct height of the device and proper positioning of the handle or cuff enable the user to walk with the least effort and the greatest comfort.

Device height should be measured with accessories, such as a rubber tip, hand cushion, and top pad, in place. The patient should wear the type of shoes that will be worn when using the device. The guidelines may need to be altered to suit a given person, with particular consideration to the individual’s body proportions, joint mobility, and motor power. Measurement also is influenced by the type of gait pattern used.

Canes

Ordinarily, the single cane is held in the hand opposite the involved lower limb. First, remove the rubber tip by twisting on the shaft, not the handle. The patient stands with the elbow slightly flexed, no more than 30 degrees. Place the cane so that the end is 5 to 10 cm lateral and 15 cm anterior to the foot. The top of the handle should be at the wrist crease ^31,^65,^73,⁸⁶ or the greater trochanter.¹¹⁰ After adjusting cane height, replace the rubber tip.

Canes that are too long cause the user to lean forward. Too short a cane imposes undue stress on the lumbosacral region. Shorter canes, however, enabled healthy subjects to perceive ground touch more accurately than with longer canes, suggesting that individuals with visual impairment will walk more safely with a slight decrease in cane length.¹¹⁴

Underarm crutches

Measure underarm crutches with the patient standing in a secure environment, such as between parallel bars. Each crutch should extend from a point approximately 4 to 5 cm (two finger breadths) below the axilla to a point on the floor 5 cm lateral and 15 cm anterior to the distal foot.⁹⁵ Hand piece placement should enable the patient to have a 30-degree resting elbow flexion angle.¹⁰⁰ Less flexion is suitable for the individual who walks by alternating foot steps.

In an alternative method used to determine crutch height, subtract 40 cm from the patient’s height ¹⁶ or make the crutch equal to 77% of the subject’s height.¹⁴ When the person is supine, the crutch extends from 5 cm below the axilla to 5 to 7.5 cm from the lateral border of the heel.¹¹⁰ In the sitting position, the patient can abduct both arms to shoulder level and extend the elbows. Crutch length is the distance from the tip of the middle finger to the tip of the olecranon process of the opposite arm.⁸⁸ An adjustable measuring crutch also can be used.¹¹⁹

Forearm crutches

The patient should stand with the crutch hand piece adjusted to provide 15 to 30 degrees of elbow flexion; more acute elbow flexion is required for gait patterns that require the user to lift both feet from the floor simultaneously. The crutch should contact the floor 5 to 10 cm lateral and 15 cm anterior to the toes. The cuff should lie on the proximal third of the forearm, approximately 2.5 to 4 cm below the olecranon process.¹¹⁰ A double-blinded repeated measures study of healthy subjects demonstrated that crutch length within 2.5 cm of the recommended length did not affect respiratory exchange ratio, walking speed, or perceived exertion.⁸⁷

Triceps crutches

The upper cuff should contact the proximal third of the arm, approximately 5 cm below the anterior fold of the axilla. The lower cuff should lie 1 to 4 cm below the olecranon process to avoid bony contact yet provide adequate stability to the arm.¹¹⁰

Platform crutches

If the crutch has a forearm platform, it should be angled so that the user has maximum comfort and control of the crutch; ordinarily the forearm rests on the platform at a 90-degree angle to the upper arm. Measuring may be facilitated with use of special devices ⁴ or variations on the techniques described.

Crutches that are too short compel the user to lean forward, whereas crutches that are too long force the shoulders up and risk compression of the radial nerve ^22,^98,¹⁰⁵ or suprascapular nerve.¹¹¹ Even properly adjusted crutches, when used incorrectly, cause some patients to experience redness, pain, and abrasion of the lateral chest; tenderness over the medial aspect of the arm; cramping of the triceps; bruising of the medial epicondyle; shoulder pain; and ulnar neuropathy.

Walkers

Most people prefer having the walker adjusted so that each handle lies at the ulnar styloid when they stand erect with the elbow flexed 15 degrees.⁴⁹

Gait patterns

Foot sequence determines the way an individual uses assistive devices.^19,^72,¹¹⁰ Selection of gait pattern(s) depends on the patient’s ability to move the feet reciprocally, tolerate full load on each leg, lift the body off the floor by pressing on the hands, and maintain balance. A gait pattern may be altered if the environment is crowded or the floor is slippery or sloping.