What is the difference between a ‘back slab’ and a full cast?

A ‘back slab’ is a slab of plaster that does not completely encircle the limb and is used for injuries which have resulted in swelling. It is secured with a bandage. This type of plaster is only temporary and will be converted into full cast at a later date as per appointment and once swelling reduces.

 A ‘full cast’ encircles the limb and does not need to be secured by a bandage. It only allows for a minimal amount of swelling.

cast is stronger than slab


How long does it take to dry?

A plaster cast will take 24 hours to dry completely although it may feel dry by the time you leave the clinic.

During this time, you should take extra care to protect the cast. For example, do not rest it on a hard surface or write on it.


Problem 1

  • The plaster cast has become too tight
  • If this happens you may notice:
  • Swelling of your fingers/toes
  • Numbness or pins and needles in your fingers/toes
  • Pain
  • White or blue discolouration of your fingers/toes and possible coldness
  • Painful rubbing in any area.
  • The first thing you should do is to raise the limb.

Arm cast: Rest cast on a pillow/cushion so that your hand is higher than your elbow.

Leg cast: Rest cast on pillow/cushion so that your foot is higher than your hip.

If the symptoms do not improve after sometime in 2-3 hours please return to us or your nearest hospital.


Problem 2

  • The plaster cast has become too loose, cracked or soft
  • Under normal circumstances you should not be able to move the cast up, down or around your limb. It should feel comfortable. It should not be cracked at any point nor should it feel soft.
  • If you notice any of these things, consult your doctor for change of plaster if required.


Important advices

  • Never use anything to scratch under the cast – the slightest scratch could develop into a serious infection.
  • Never trim or cut down the length of the plaster cast yourself, or attempt to tuck in extra padding.
  • Never apply talcum powder or any other disinfectant under the plaster cast
  • Never allow your cast to become wet as this will weaken it. You can use a plastic bag to cover up the cast when you have a bath or shower. Use sticky tape or a rubber band to seal the bag to make it watertight.
  • If walking is advised, wear protective cast shoe to prevent breakage of cast
  • If walking is not advised, do not walk on the cast as this can hamper with fracture healing
  • We strongly advise that you do not drive with any type of plaster cast.
  • Duration of the plaster depends on the type of injury, discuss with us.
  • you should exercise in order to avoid stiffness in unaffected joints. We recommend that you try the following gentle movements every couple of hours during the day.

Arm cast:

  • Wiggle your fingers.
  • Bend and straighten your elbow joint (only if the plaster ends below the elbow).
  • Very gently rotate your shoulder.

Leg cast:

  • Wiggle your toes.
  • Bend and straighten your knee (only if the plaster ends below the knee).
  • Gently clench the muscles in the back of your calf and thigh to improve the blood flow.

Do follow up as per advice to ensure your fracture is healing in a proper position

Plaster removal will be decided by the doctor, do not remove the plaster by yourself.

Rarely while removing plaster there can by minor scratches which sometimes are unavoidable particularly on bony prominences.