My child can't sit up straight and fidgets a lot at school. What is the reason?

Young children entering formal schooling are required, perhaps for the first time ever, to sit and work at a table for fairly long periods of time.  To do this easily a child needs adequate flexibility, muscle strength,coordination and postural  control. 

Children who are fit and flexible naturally sit erect when working at a table. 

 Young child sitting erect     Sitting erect for drawing

Children who fidget, move around and slump when sitting often lack the necessary fitness and stamina for sitting; they often find sitting erect causes discomfort in the back and legs. 

What is needed for sitting erect with ease and comfort 

  • Hip flexibility  to allow the thighs to rest parallel to each other on the seat of the chair with the pelvis vertical.
  • Trunk flexibility and muscle endurance to keep the trunk erect with ease and comfort. 
  • Neck flexibility and muscle strength to keep the head erect and steady when moving the arms.
  • Trunk stability: the ability to keep the trunk and head steady when moving the arms.  



Why do some children have difficulty sitting erect? 

Tightness in the hip muscles 

A slumped posture is usually associated with tightness in the muscles that cross from the lower back over the back and sides of the hips. 

This tightness makes it difficult and uncomfortable to bend the hips to 900 with the thighs parallel. To compensate the child tips the pelvis backward, flexes the trunk and moves the legs apart and sometimes lifts the heels up.  How to check for tight hip muscles 

T sitting slumped_2.jpg

If you ask a child with tightness in the hip muscles to sit erect with the thighs parallel they complain of discomfort in the lower legs and sometimes in the back. 

 Child discomfort  sitting erect.jpg

Weakness and poor endurance in the back muscles 

When you sit up straight the back muscles must work to keep the trunk erect. If they are weak and have poor endurance sitting erect becomes tiring.  The child relieves the discomfort by leaning on the arms when working at a table or may prop up the head with an arm.

Weakness and poor flexibility in the neck muscles

A child who sits with the trunk flexed has to extend the neck to lift the head to see ahead.  This leads to tightness in the neck extensor muscles along with weakness in the neck flexor muscles. This combination makes it difficult to hold the head erect when working at a table. 

The child may support the head on the hand when the neck muscles get tired. 

Poor postural (core) stability

Children with poor sitting posture very often also have difficulties keeping the trunk and head steady when moving the arms.  

When the child lifts the arm sideways  the trunk is may tip sideways rather than stay erect.  


Try the following with your child

Let your child sit on a stool, lift the arms to shoulder height and stay in this position for 20 slow counts.

A child with good head and trunk(core)  stability can maintain this position with ease. 


Children with poor trunk (core) stability find maintaining this position hard work. The trunk may slowly drift backwards the longer the child holds the position. 



Fidgeting may be a sign of anxiety

If a child finds a task difficult it may cause anxiety, raise arousal levels and lead to anxious fidgeting. 

Try the following

Let your child sit at a table and  play a game that he/or she enjoys and finds relatively easy.

Next, let your child do a drawing or writing task that he/she finds difficult and would rather avoid doing.  

Observe your child's posture during each of these tasks. 

Does the nature of the task affect your child's posture and  tendency to fidget? 

Does your child sit erect, with good attention for the easy, enjoyable task, but start fidgeting and start to slump for the challenging task? 

Read more

Core muscle weakness and poor core stability

Assessing core muscle weakness and stability in sitting 

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Identify why your child has difficulty sitting erect and fidgets a lot

  • Is it discomfort from tight muscles? Does anxiety play a role?  

Active stretching exercises for flexibility

  • Exercises that are fun to do and give immediate improvements in sitting ease and comfort 

Exercises to strengthen the upper back and neck muscles 

  • To decrease fatigue and discomfort 

Activities to train stamina and good sitting habits 

  • For table top activities, drawing and handwriting tasks