A nightsplint is an orthopedic device designed to treat a variety of foot injuries by bending the foot upwards at the ankle during sleep. It is primarily used to treat plantar fasciitis, although it can be used to treat Achilles tendonitis.
By maintaining a gentle but constant stretch during sleep, the tendon heals at its full functional length. (You normally sleep with your toes pointed.) Without the splint, the tendon would heal in a shortened position. The second the foot hits the floor in the morning, the tendon stretches and negates any healing. The splint prevents this daily reinjuring.
It is possible to make your own splint, but by far the easiest is to either buy one or have a doctor provide one. Most nightsplints look like a ski boot with the top and toe removed. Usually there are four velcro straps: two to hold the splint on and two for evenly adjusting the foot position.
The splint is attached to the leg at the shin and ankle. Then the two straps on the side are pulled upward to stretch the foot as much as is comfortable and then fastened. Turn off the lights and go to sleep.
Despite the fact that the healing process is supposed to take place during sleep, actually sleeping with a splint takes some practice. Be prepared for some tossing and turning as well as some middle-of-the-night re-strapping of the splint. Usually the doctor will advise a week or two with the splint, just the amount of time it takes to get comfortable with it.
Another thing: don't attempt to walk in a nightsplint. Though the bottom of most of them has a rubber sole -- so that people don't slip and smash their butts on the way to pee at 2 a.m. -- doing so may put a cramp the size of a baseball in the offending foot's neighboring calf. Just some advice.
However, a nightsplint is worth every inconvenience.
Enduring a welcome but fitful sleep, the abnormal stretch in the Frankenstein boot diffused by the splendid voices booming across the ocean via the BBC, there is a peace knowing that in a few weeks the nagging sharp pain accompanying every other step will be gone thanks to the body repairing itself. Then the morning trip to start the coffee won't be something out of a horror movie.
From there the possibilities bloom -- playing soccer once again with children, walking with a loved one to the farmer's market, taking the first tentative steps toward a pre-dawn jog.
I love my nightsplint.