Essential Medical Skills to Acquire: Splinting and Casting, by Cynthia J. Koelker, MD

In the introduction to this series I gave a brief outline of the medical skills that a layman should acquire when preparing for TEOTWAWKI. Injuries will be common among people required to be more active than they are accustomed to.   Lacerations have already been addressed in Parts 1 and 2 of this series.  Next we will turn to injuries that required immobilization for optimal healing including sprains, strains, and fractures.

To begin, what’s the difference between a strain and a sprain?
  To strain means to overstretch a muscle or tendon beyond its capacity to resist without tearing.  A sprain means essentially the same thing but applies to ligament injury.  A tendon is the fibrous termination of a muscle that attaches the muscle to a bone.  The next time you eat a chicken leg, note that the rubbery part of the meat near the end of the bone is the tendon, which often maintains its bony attachment. In contrast, a ligament connects two bones but without a muscle, much like a strong semi-elastic band. Neither tendons nor ligaments have a good blood supply, which accounts for their slow healing.  Knees are usually sprained, that is, the supporting ligaments are damaged.  Ankles are commonly sprained as well, but since the leg muscles terminate near the ankle, it is sometimes difficult to tell a sprain from a strain.  An Achilles tendon injury would be called a strain, but a twisted ankle is usually a sprain.  In a sense, a sprain is a subset of strain-type injuries, and knowing the difference is not essential.

Next, what’s the difference between a break and a fracture?
  There is none, though many patients seem to believe that one or the other is worse.  Medically speaking, they are equivalent terminology. 

With any muscle or bone injury, the damage may be mild, moderate, or severe.
  Regarding strains and sprains, mild injuries generally resolve within minutes to hours, and involve only microscopic tears at most.  They do not swell, cause bruising or persistent pain.  The classic example is a twisted ankle, which limits walking for a brief time, but reverts to normal after a short rest.  Patients rarely seek medical care for this degree of injury.  These mild injuries are often termed first-degree.  Third-degree injuries involve complete disruption of the muscle, tendon, or ligament, where the tissue is “torn in two.”   The second-degree classification covers everything in between, from injuries that require days to heal to injuries that may cause permanent impairment.  Without surgery as an option, third-degree injuries will rarely heal.  Second-degree injuries are what patients typically seek medical help for and where you can become an excellent resource.
As for bones, a good mental image is that of Styrofoam, which can be crushed, slightly bent, or broken.  A stress fracture is analogous to crushing; a greenstick fracture is similar to bending; a complete fracture is like breaking the foam in two; a comminuted fracture is like breaking the foam into multiple pieces.

Strains, sprains, and bones heal by gradually filling in the gap
.  To do so efficiently, the gap needs to be minimized and stabilized in good position until sufficient healing occurs.  Immobilization prevents further injury and facilitates quicker healing.

Immobilization may be accomplished by any means that achieves the above requirements.
  One significant advance in recent decades is the recognition that prolonged bed rest leads to blood clots which may kill.  Therefore, it is best to immobilize only the affected area and encourage movement otherwise.

Traditionally plaster splints and casts have been employed, but they are not the only option.
  In my classes I teach both techniques and principles.  After learning how to apply plaster correctly, I encourage students to improvise with materials on hand.  Adequate splints may be manufactured from cardboard, Styrofoam, wood, plastic, duct tape, magazines, etc.
However, the benefit of plaster is versatility and durability.  A 3 or 4” roll of plaster can be adapted for use on essentially any body part.  The material is easily cut to smaller dimensions if needed.  A properly constructed splint or cast can last for the required duration, whereas other materials will likely need to be removed and replaced periodically. 
It behooves anyone prone to injury – which is all of us – to learn to apply a plaster cast or splint.  The technique of working with plaster is fairly simple, though mastery of diagnosis, positioning, timing, and adequacy of healing takes longer to acquire.  Even if you don’t plan on being the sole medical provider for your group, a doctor would appreciate the assistance of someone with knowledge of casting.

Any injury that is suspicious for a sprain or break should be immobilized
with a splint and re-evaluated regularly.  A doctor may be confident that an injury could be re-checked in a week or two, but for the layman, I’d advise checking daily until the situation is clarified.  A cast may be applied later if needed.  Accurate diagnosis is not always possible, so immobilizing until pain, swelling, and bruising are resolved is indicated.  Full weight-bearing should be avoided until walking can be accomplished with little if any discomfort.  Don’t forget to stock crutches or a walker for potential leg injuries.

Anyone can purchase Gypsona plaster bandages online without a prescription
, as well as cast padding and stockinette.  Even if you don’t plan to cast or splint yourself, having the equipment on hand is advisable for emergency use.  I recommend investing in the following:
1 case each 3” and 4” Gypsona plaster bandages
1 box each 3” and 4” stockinette
1 case each 3” and 4” cast padding (synthetic is least expensive)

Additionally, you will need a bowl, bucket, or basin for wetting the plaster, a tarp or other floor covering to protect against plaster drippage, and a source of water, preferably warm.  Using cold water will take longer for the plaster to set; using hot water will shorten the period and may cause burns, since plaster heats as it sets.  Gloves are not mandatory but they do minimize the mess.  Protective clothing is rarely necessary. 
If you cannot afford both 3” and 4” supplies, I’d advise only 4” plaster which can be trimmed as needed along with 3” cast padding.  Applying stockinette underneath the cast padding yields professional results, but a thin sock could be substituted, or simply use cast padding alone.

For arm splints and casting, the plaster width should equal the width of the palm; for leg splints the plaster width should be a little wider than the widest part of the foot; for leg casts, 3” or 4” plaster works well applied from the foot to the ankle, then 4” or 6” plaster from the ankle to below the knee.  

One important point that I stress repeatedly is to NOT apply a cast unless you are sure no further swelling will occur.  Splints are fine and are secured with elastic wraps or gauze, which has some give to them and can be easily loosened.  A circular/circumferential cast may compromise the blood or nerve supply to the injured part if it becomes too tight due to increased swelling.  A fracture is rarely an emergency, and a splint may be applied for a few days until it is clear that further swelling is unlikely.  Before applying any cast check the circulation, sensation, and movement in the affected limb, then check again after application.  If there’s any question that the cast is too tight, remove it immediately.  Pressure sores beneath a cast can take months to heal or yield permanent problems, even infection and death.

Never apply a cast over an open wound, unless you are able to cut a window in the cast for frequent inspection.  Even then, applying a cast may be a problem if swelling occurs and bulges through the opening.  It’s best to use only a strong splint until the skin is completely healed.
Nowadays cast removal is typically accomplished using an oscillating cast saw, but any plaster cast can be removed by wetting the cast thoroughly and gradually unraveling or cutting it off, layer by layer, especially when electricity is not available.

Numerous YouTube videos demonstrate plaster splinting and casting, so I’ll not go into detail here.  The most useful are short arm casts and splints, and short leg casts and splints.  (Short means below the elbow or below the knee.)  For those who prefer live instruction, see my web site at for upcoming hands-on training opportunities.