source: this website
For lower-limb injuries (broken leg, broken ankle, sprained ankle, knee injuries), as well as after lower limb surgery, crutches can be used to decrease discomfort, reduce recovery time, and assist walking. Often, when a cast is put on the leg or on the foot, or in the case of weak muscles or gait instability, the use of crutches might become necessary for a period of time. Crutches may also be used by amputees, and people with other disabilities that make walking difficult.
A crutch must do two things: reduce the body weight load on the injured limb and broaden the user’s support base to improve their balance and stability. The support also should assist upright movement and transmit sensory cues through the hands. The main benefit provided by crutches is the ability to keep an upright posture and, therefore, to be able to maneuver in places that could not be reached, for instance, with a wheelchair. Regaining upright body movement aids circulation, assists kidney and lung functions, and helps prevent calcium loss from the bones.
Crutches shift the force of upright movement from the lower limbs to the upper body. The user must have sufficient arm strength, balance, and coordination to use them effectively. There are several basic types of crutches:
- axillary / underarm crutch – the most common type, can be adjusted easily to the user’s overall height and hand height;
- forearm / Lofstrand / elbow crutch – allows 15°-30° elbow flexion-extension movements, letting the user bear a greater weight;
- platform / triceps crutch – conceived to avoid bony contact on the arm, though providing stability;
- strutter crutch – provides larger crutch tips that remain flat on the floor and allow for improved weight distribution and more even walking gait;
- leg support crutch – like a knee scooter, the affected leg is strapped into a support frame on wheels. This type of crutch is particularly useful for below-the-knee injuries or postoperatively after surgeries that affect one leg only.
Walking with crutches is not easy. Studies have shown that the wrist joints receives from 1 to more than 3 times the body weight during the swing phase of walking with crutches, a load that the upper body was not designed to sustain. Crutch comfort can become an issue, as the user’s body acclimates to their use.