Below knee cast

Picture of cast from calf till the mid of the feet

Doctor's advice

Your doctor’s advice

A doctor has assessed you and decided you need to go into a below knee cast.

Applied to lower leg including the foot and ankle.

Immobilises the ankle, preventing rotation and flexion/extension of the foot.

Often applied to treat fractures/injuries of the distal aspect of the lower leg including the ankle and some fractures/injuries to the foot.

It is common for patients in below knee casts to be allowed to weight bear at the discretion of their consultant.

✓ Do

Keep your cast clean and dry

Getting it wet could irritate your skin. Either wrap a towel around it and keep away from water or purchase a waterproof cover (these are available online).

Do some exercises

Its important to keep your toes and knee moving. Clench your toes and open for 10 minutes every hour – this will help keep the muscles active and help the circulation. Its important to keep bending and straighten your knee.

Keep the casted leg elevated

When you are either laying down or sitting, rest your leg on a cushion or pillow with your heel higher than your hip and your knee.

Get help if you need it

Contact plaster room if your cast becomes broken.

Be vigilant of cast rubbing/burning sensation inside cast. Contact plaster room ASAP.

Don't ✘

Don't remove your cast

Never attempt to remove a cast yourself unless you have been given specific instructions to do so.

Don't put plastic bags around the cast

Do not put plastic bags around the cast, these are not waterproof and can cause skin issues under the cast.

Don't stick objects in your cast if itching

This can cause additional skin problems under the cast that may require further medical treatment.

Never attempt to trim your cast

If there are rough edges or your skin is irritated around the ends, contact plaster room.

Warning sign


Swelling or the symptoms of swelling of the lower limbs is common post injury/surgery swelling will go up and down depending on the activity the patient is doing at the time.

Symptoms can include

  • Numbness or tingling in leg, foot or toes.
  • Throbbing sensations in casted leg/foot.
  • Change of skin colour to exposed areas of skin not in cast
  • Cast may feel tight
  • May be more prevalent in the morning or if casted leg has not been elevated

What to do

In order to alleviate swelling/symptoms of swelling, leg must be elevated with the foot higher than the hip joint – ideally toes in line with nose this should be done as much as possible – swelling is very common if you have had the leg elevated then you bring your leg down, it will swell but just need to elevate as soon as possible.

It is very important to keep the joints not in cast moving. See exercise video.

Do not rest foot like this

Picture of cast from calf till the mid of the feet

Rest foot like this

Picture of cast from calf till the mid of the feet

Better understand the pressure points

It is important to be vigilant of upper limb casts rubbing/causing pain. Prolonged pressure on a certain area has the potential to cause skin damage. Common areas this could occur in are

  • Around the heel and ankle area
  • Around the edge of the casts
Ankle and heel area
Be vigilant of rubbing/burning sensation around the ankle or heel area
Picture of cast from calf till the mid of the feet
Check edge of cast
Check edges of cast daily for red or sore areas better understanding of pressure points
Picture of cast from calf till the mid of the feet

See our self-help videos

Care of below knee cast

Removal of below knee split cast

VACOped boot

Warning sign

VACOped boot

Your recovery process

2–4 weeks post injury

  • Return to Acute ED MSK clinic at 2/52 to remove equinus cast, apply VACOped boot, and demonstrate initial exercises.
  • VACOped boot locked at 30° equinus (30degree wedge).
  • Progress to weight bearing as tolerated with elbow crutches.
  • Must be in boot at all times including sleeping in boot (external heel can be removed at night).

4–7 weeks post injury

Physiotherapy outpatients

  • VACOped boot 15–30 degrees (30degree wedge).
  • Weight-bearing as tolerated in boot. 
  • Ensure patient familiar with inflating/deflating the boot liner.
  • Patient to sleep in boot (external heel can be removed for sleeping).
  • Pre-injury Achilles Tendon Total Rupture Score (retrospective) at physio.
  • Exercises in boot:
    • Isometric plantar flexion against boot
    • Resisted plantar flexion in knee extension and flexion with yellow theraband at 5 weeks – avoid using the long toe flexors.
    • Active plantar flexion and dorsiflexion to limit of boot.

7–9 weeks post injury

Physiotherapy outpatients

  • Vacoped boot 0-30 degrees plantar flexion.
  • Flat wedge.
  • Full weight-bearing in boot.
  • Exercises in boot:
    • Static bike with no resistance.
    • Seated calf raises in VACOped.
    • Continue ROM exercises to limit of boot.
    • Progress theraband resistance with plantar flexion strengthening.

9–10 weeks post injury

Physiotherapy outpatients

  • VACOped boot unlocked.
  • Can remove boot at night in bed.
  • Full weight-bearing.

Contact us

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Before you ring us…

It is really important that you use this Plaster Room site to access all the advice and information that we think essential for your successful recovery.

Get help if you need it

Please only ring us for one of these specified reasons:

  • if your cast becomes broken
  • if you have a cast that is rubbing or burning
  • if the cast is causing red area around the edge of the cast
  • if you have pain that cannot be controlled with pain relief

Tel: 01274 364174