An assistive device (AD) is a piece of equipment designed to aid a person who is unable to walk without assistance in ambulating safely. The indications for use of an assistive device include:
- The inability to be full weight bearing on a lower extremity due to injury, loss or structural deformity. A common example is someone with a broken leg or ankle.
- Muscle weakness or paralysis of the lower extremity or trunk. A person with a spinal cord injury or a post polio patient would fit this category.
- Decreased or poor balance. Often an elderly person or someone with a neurological disorder will demonstrate balance deficits.
Assistive devices are chosen for each individual based on the amount of stability and support required as well as the patient's strength, cognition, balance and coordination. If recovering from an injury or disease, patients are often instructed in the use of an assistive device during their rehab. A specific gait pattern is required to correctly use the device and requires a lot of concentration initially to learn to walk correctly. A physical therapist or health care worker trained to work with gait problems should select the appropriate assistive device for each patient.
The following are assistive devices ranked in order of most stable to least stable
- Parallel bars – A set of two parallel metal bars spaced anywhere from 22 inches to 36 inches apart on supporting stands with variable lengths. More elaborate bars are mounted on a wooden platform and have electric controls to adjust the width and height for each individual patient. For clinics with limited resources there are some wall mounted bars which can be used for standing and balance training. In training a person to restrict weight bearing, the shoulder depressor and elbow extensor muscles are used to lift the patient's body weight during ambulation.
- Advantages: extremely stabile and supportive.
- Disadvantages: Site specific training, not functional for home use, fosters sense of dependence.
- Uses: Initial gait training and standing with patients who have poor balance or paralysis or to instruct in weight bearing status following an orthopedic injury. Initial use of another AD may be attempted inside or beside the bars to provide a sense of security.
Walker – A four legged metal frame with handles for assistance with walking. Variations include the standard walker with 4 flat legs, the rolling walker with two front wheels and 2 flat posterior legs, the 4 wheeled rolling walker, the reverse walker used with children, 3 wheeled walkers and reciprocal walkers. For patients with restricted weight bearing, the lifting of body weight is accomplished through use of the shoulder depressors and elbow extensors.
Options include platforms which can be mounted on either or both sides of the walker to allow the forearm to rest parallel to the floor in cases of hemiplegia or wrist fractures. Weight bearing is then transferred through the elbow instead of the hand and wrist, with the shoulder depressors providing the lift to advance the body during gait.
More elaborate wheeled walkers may have hand brakes or a seat attached for the patient to rest when fatigued. Walkers with more than 2 wheels are only used for patients with limited endurance who do not have balance or orthopedic injuries.
Walkers come in junior, regular, extra wide and tall sizes and adjustable to the height of individual.
- Advantages: Very stable (standard walker) to moderately stable (rolling walker), easy to use, requires less balance and strength than crutches.
- Disadvantages: More cumbersome than crutches, especially non-folding models, will not always fit in small spaces, unsafe on stairs without assistance.
- Uses: Patients with restricted weight bearing unable to use crutches, elderly people with balance deficits who are unsafe walking with a cane, patients with limited endurance due to respiratory or cardiac disease.
Crutches- One of the most well known of the assistive devices, some form of staff or crutch has been used to assist lame or infirm people to walk for centuries. The two basic types are:
- Axillary crutches – The most common type, may be made of metal or aluminum. Axillary crutches have a padded triangular upper surface narrowing to a single foot with a rubber tip at the distal end and a hand grip in the middle. Designed to rest in the space below the arm pit or axilla, the weight of the body is borne though the hand and wrist using shoulder depressors and elbow extensors to lift the body. Although most often used in pairs, a single crutch may be used in the same manner as a cane for increased stability (Think Tiny Tim).
Sizes range from children's or juniors to average and tall adult. Both the hand grip and the length are adjustable and should be fitted to each person. Not ever 5' 8" person has the same torso length or arm span.
- Forearm or Loftstrand crutches – aka Canadian crutches are most often used for persons with permanent disabilities since they are lighter and offer more freedom of movement. Made of metal, they consist of a cuff that fits below the elbow, a hand grip and a shaft ending in a rubber tip. Weight bearing is again accomplished by virtue of the shoulder depressors and elbow extensors with the force transferred through the elbow and hand. As with axillary crutches, forearm crutches must be custom fitted to the individual.
- Advantages: Moderately stable, light weight, easily portable, appropriate for use on stairs
- Disadvantages: Requires more coordination and balance to use correctly than a walker as well as increased strength and endurance. Forearm crutches are slightly more difficult to learn to use than standard crutches and not appropriate for patients with decreased trunk stability.
- Uses: Patients with restricted weight bearing on one or both legs, paralysis or weakness in lower extremities or trunk. One crutch may also be used to progress from two crutches toward independent ambulation as the patient improves.
Canes- Often referred to as a "walking stick," canes are the oldest form of assistive device. Staffs and scepters were used as signs of authority by bishops and kings centuries ago. Made of wood or aluminum, canes have limited ability to reduce weight bearing and are frequently used by the elderly or persons with decreased balance. Canes come in two varieties:
- Standard or straight cane - The simplest type of cane, it consists of a shaft with a rubber tip at one end and a handgrip at the other. Aluminum canes are adjustable at the base and are very lightweight. Wooden canes must be cut to be adjusted to the correct height for the person using it.
It wasn't very long ago that using a cane signified style and wealth and was part of the essential gentleman's attire. Many an elderly person has proudly brandished a beautifully carved cane embedded with gold or jewels.
- Quad cane - So named because it consists of a base with 4 "feet" attached to provide increased stability. Unlike a straight cane, quad canes will stand alone so they are not easily misplaced. Options include a large or small base attached to a shaft with a handle grip at the top. The larger the base, the more stable the cane. The shaft will telescope up or down to allow height adjustment for each individual.
- Advantages: Lightweight and portable, best AD for mild balance disorder, minimal (standard) to moderate (large base) stability
- Disadvantages: Limited weight bearing capacity, much less stable than a walker for moderate to severe balance disorders, requires cognition and coordination to use appropriately.
- Uses: Persons with mild balance disorders, slight weakness or pain in one or both lower extremities.
Source: Patient Care Skills, 3rd ed.
Mary A Duesterhaus Minor, MS,PT
Scot Duesterhaus Minor, PhD,PT