What is serial casting?
Serial casting is a treatment used to gradually stretch tight muscles in a child’s legs. A weight-bearing plaster cast is applied and left in place for two weeks. The cast is then removed to assess the stretch achieved and a new cast applied if further stretching is required.
Most children require around four weeks of casting (two casts).
Because muscles weaken during immobilisation, children are referred to physiotherapy after the casts are removed to rebuild strength and maintain the improvement.
When is serial casting used?
Below-knee casts (calf muscle stretching)
These are used for:
Above-knee casts (hamstring stretching)
These are used for:
Painful feet associated with hamstring tightness
Duration of Treatment
Typical Duration:
Can both legs be casted at the same time?
Is physiotherapy needed afterwards?
Yes — physiotherapy is essential.
Casting stretches the muscle but temporarily weakens it.
The weakness usually lasts roughly the same length as the casting period (e.g., 4 weeks of casting → ~4 weeks of weakness).
Physiotherapy helps to:
Can the tightness come back?
Yes. Serial casting stretches the muscle but does not treat the underlying cause of tightness. As the child grows, muscles may tighten again.
Regular home stretching exercises are therefore important.
Serial casting can be repeated if symptoms recur.
Alternatives and when surgery is considered
First-line treatment
If symptoms persist
If tightness continues despite these treatments
Surgical muscle or tendon lengthening may be considered (usually after peak growth).
Surgical Risks