Water impervious boot for protecting a surgical cast

A light weight flexible boot to be worn over a foot in a surgical cast and protect the cast from moisture. The boot has a walking sole of tough rubber type material with a cushion sole and an upper body composed entirely of flexible and elastic foam material, with an inner fabric layer and an outer covering of water impervious fabric. The boot can be stretched over various sizes and shapes of casts and all joints in the boot are completely sealed and waterproof.

BACKGROUND OF THE INVENTION 
Surgical casts on the foot and lower leg are often applied so that the 
wearer can walk on the affected leg, with appropriate care. Some casts are 
made with a small stud or foot built in to hold the cast off the ground. 
This makes walking difficult since one leg is then effectively larger than 
the other. It is also common practice to wear a thick sock or a cut away 
shoe over the cast for protection. However, none of these techniques will 
keep a cast dry, particularly if it becomes necessary to walk through a 
puddle, or in snow. 
The inventor has a U.S. Pat. No. 4,098,268 entitled "Water Impervious Cover 
For An Arm Or Leg Cast", which discloses an elongated sheath for 
completely covering a cast. The open end is sealed by pulling a strap 
tight and the interior may be inflated. This particular protector permits 
total immersion of the limb in water, as in a therapeutic bath. However, 
such total protection is not always necessary and for walking in rain or 
snow, a simple slip on boot would be sufficient. 
SUMMARY OF THE INVENTION 
The protective boot described herein, is a simple slip on boot with a 
walking sole of tough rubber type material and an upper body of flexible 
and elastic foam material. The exterior of the body has a bonded covering 
of water impervious fabric, such as closely woven nylon, which also 
strengthens the body. The inside of the body also has a bonded layer of 
soft fabric for comfort and wear resistance and a fabric covered foam 
cushion inner sole is secured to the walking sole. All seams and joints in 
the construction are completely sealed by a water impervious adhesive, the 
peripheral joint of the body to the sole and the seams in the body also 
being stitched for strength. The boot has sufficient elasticity to be 
stretched over casts of different sizes and shapes with minimum effort. 
The primary object of this invention is to provide a new and improved water 
impervious boot for protecting a surgical cast. 
Another object of this invention is to provide a cast protecting boot 
having a walking sole and a light weight upper body of flexible foam 
material. 
A further object of this invention is to provide a cast protecting boot 
which is covered and strengthened by water impervious fabric.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The boot has a sole 10 of tough rubber type material to withstand the wear 
of walking, and a light weight flexible upper body 12. The boot may be 
made in various sizes and the body is shaped to enclose a foot in a cast. 
As illustrated, the boot would extend slightly above the ankle, but could 
be made higher. However, the boot must be easy to slip on over a cast 
without having an unduly large leg portion and upper end opening. The 
underside of the sole may be provided with any suitable non-slip surface 
or tread configuration. 
Body 12 is made with a flexible foam shell 14 of Neoprene or similar 
resilient material, which is soft and tear resistant and will hold a 
particular shape without permanent deformation. The body can be made in 
several pieces and is illustrated as being made in two sides joined at 
front and rear seams 16 and 18, respectively. 
The exterior of the body 12 is covered by a water impervious fabric layer 
20 integral with or bonded to the foam shell. Fabric layer 20 is 
preferably of closely woven nylon, or the like, the material being well 
known in the construction of wet suits for divers. For comfort and 
strength the interior of the body is covered by an inner fabric layer 22 
of soft material, bonded to the foam shell. One such material, comprising 
the foam with fabric on both sides, is readily available and is sold under 
the trade name of Rubitex G-231. 
The front and rear seams are made as typified by seam 16 in FIG. 4. The 
edges of the foam shell 12 are butt jointed by a waterproof adhesive 24 
and the entire length of the seam is overstitched by stitching 26 through 
the outer fabric layer 20. 
In the junction of the body 12 to sole 10, the entire periphery of the 
shell 14 is butt jointed to the top surface of the sole by waterproof 
adhesive 24. For strength the entire periphery of the body is also secured 
to the sole by stitching 28 through the outer fabric layer 20 and the sole 
10, as in FIG. 3. 
A resilient inner sole 30, of foam Neoprene or the like, is bonded to the 
top surface of sole 10 by adhesive 24, and is also bonded by the adhesive 
to the inner surface of body 12 around the entire inner periphery of the 
body. The outer edge 32 of the inner sole 30 is cut at an angle, as in 
FIG. 3, to fit closely against the contoured inner surface of the body and 
provide maximum bonding area. The top surface of inner sole 30 is covered 
by a fabric layer 34, of material similar to inner layer 22. 
It should be noted that the adhesive 24 is shown as having a definite 
thickness for purposes of illustration. In manufacture, the bonding would 
be performed by a solvent to provide an adhesively welded joint with no 
actual separation of the parts. 
While dimensions are not critical, details of the various parts will serve 
to indicate the versatility and function of the boot. The body material, 
for example, has a foam core about 1/8 to 5/32 of an inch in thickness, 
while the foam inner sole is about 1/4 to 3/8 of an inch thick to protect 
the cast under the weight of the wearer. 
The sole is from 3/16 to 1/4 of an inch thick and while being tough and 
considerably harder than the foam, is still flexible enough to facilitate 
pulling the boot on over a cast. The elasticity of the body material 
allows stretching to pass over a cast, while keeping the leg opening 36 
small enough to fit closely around the leg and prevent water from dripping 
inside the boot. It has been found that when putting the boot on, the fit 
is usually tight enough over a cast that air is trapped in the boot and 
forms a cushion around the foot. This air pocket reduces perspiration 
compared to that experienced in an overall tight fitting impermeable 
covering. The flexible and elastic body makes it possible to retain the 
boot in place over a variety of casts, without the need for straps or 
fasteners. 
By adhesively sealing all portions of the structure together, the boot 
becomes a unitary water impervious envelope, which allows the wearer to 
wade through puddles or walk in snow without getting the cast wet. The 
cushioned walking sole provides good protection for the cast and extends 
the useful life of the boot. The inner fabric layer adds to the strength 
of the boot and protects the foam shell from wear by any rough spots on 
the cast. Usually the wearer would wear a light sock over the foot for 
added comfort, but this is not essential. 
When constructed as described, the boot is machine washable, and due to the 
strength and wear resistance incorporated in the structure, can be used a 
number of times.