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A crutch is a mobility aid that transfers weight from the legs to the upper body. It is often used for people who cannot use their legs to support their weight, for reasons ranging from short-term injuries to lifelong disabilities.
Contents
Types
There are several types of crutches:
Underarm or axilla
Axillary crutches are used by placing the pad against the ribcage beneath the armpit and holding the grip, which is below and parallel to the pad. They are usually used to provide support for patients who have temporary restriction on ambulation. With underarm crutches, sometimes a towel or some kind of soft cover is needed to prevent or reduce armpit injury. A condition known as crutch paralysis, or crutch palsy can arise from pressure on nerves in the armpit, or axilla. Specifically, "the brachial plexus in the axilla is often damaged from the pressure of a crutch...In these cases the radial is the nerve most frequently implicated; the ulnar nerve suffers next in frequency."
Forearm
A forearm crutch has a cuff at the top to go around the forearm, also known as the Lofstrand crutch. It is used by inserting the arm into a cuff and holding the grip. The cuff, typically made of plastic or metal, can be a half-circle or a full circle with a V-type opening in the front allowing the forearm to slip out in case of a fall. A forearm crutch are more likely to be used by patients who have permanent limitations and will always need crutch assistance for long-term ambulation.
Platform
These are less common and used by those with poor hand grip due to arthritis, cerebral palsy, or other conditions. The arm rests on a horizontal platform and is strapped in place. The hand rests on a grip which, if properly designed, can be angled appropriately depending on the user's disability.
Leg Support
These non-traditional crutches are useful for users with an injury or disability affecting one lower leg only. They function by strapping the affected leg into a support frame that simultaneously holds the lower leg clear of the ground while transferring the load from the ground to the user's knee or thigh. This style of crutch has the advantage of not using the hands or arms while walking. A claimed benefit is that upper thigh atrophy is also reduced because the affected leg remains in use. Unlike other crutch designs these designs are unusable for pelvic, hip or thigh injuries and in some cases for knee injuries also.
Walking sticks or canes serve an identical purpose to crutches, but are held only in the hand and have a limited load bearing capability because of this.
One crutch
When using one crutch, the crutch is placed on the side of the unaffected leg.
4-point gait
Those who can tolerate partial weight bearing on both legs usually use the four point gait. The sequence is right crutch, left leg, left crutch, right leg.
2-point gait
Those who can tolerate partial weight bearing on both legs but require less support than a four point gait usually use the 2-point gait. The sequence is right crutch with left leg and then left crutch with right leg.
3-point gait
The three point gait is usually used by those who cannot bear weight on one leg. Both crutches are advanced while bearing weight on unaffected leg. Then the unaffected leg is advanced while bearing weight on the crutches.
Swing-to gait
A person with a non-weight bearing injury generally performs a "swing-to" gait: lifting the affected leg, the user places both crutches in front of himself, and then swings his uninjured leg to meet the crutches. A similar "swing-through" gait is when the both legs are advanced in front of the crutches rather than at the next to the crutches.
Stairs
When climbing up stairs, the unaffected leg is advanced first, then the affected leg and the crutches are advanced. When descending stairs, the crutches are advanced first and then the affected leg and the unaffected leg.
Alternative devices
The knee scooter and the wheelchair are possible alternatives for patients who cannot use or do not like crutches. These wheeled devices introduce an additional limitation, however, since they cannot negotiate stairs.
Materials
- Wood
- Metal alloys (most often Steel, Aluminium alloys, Titanium alloys)
- Carbon or glass fiber reinforced composites
- Thermoplastic
- Carbon fiber reinforced polymer