Children who fidget, move around and slump when sitting often lack the necessary muscle strength, flexibility and endurance for maintaining an erect posture: they may find sitting erect causes discomfort in the back and legs.
Sitting erect and keeping the head steady when moving the arms for hand tasks, drawing and handwriting also requires good postural stability and coordination.
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.
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.
Try the following
Ask your child to sit erect and still for a minute.
Watch how he/she responds at the end of a minute. Often there is a sigh of relieve as the child moves back to a more comfortable slumped position.
Children with tight muscles are usually quite clear about where they experience discomfort: sometimes it is in the back, but more often it is in the lower legs.
Weakness and poor endurance in the back muscles
When a child sits 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.
A child with joint hypermobility needs extra muscle action to support the spine in extension because the spinal joints have less inherent stability.
If the child habitually sits with a flexed spine, the extensor muscles become lengthened (overstretched) and as a result when the child does sit up straight the muscles are less responsive to the signals from the brain that set the background muscle tone. This means that sitting erect requires more conscious mental effort.
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 and bring the face vertical.
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.
Keeping the head steady when sitting erect involves tipping the head forward on the spine.
The muscles in the front of the neck (neck flexors) work to keep the head steady when the arms are moved.
Keeping the head erect and steady is difficult if the neck extensor muscles are shortened and the neck flexor muscles are weak.
Poor postural stability
Children with poor sitting posture very often also have difficulties keeping the trunk and head steady when moving the arms. When they lift the arm sideways the trunk tips sideways.
The child who fidgets and shifts around in the chair
There are two reasons why children fidget when sitting and working at a table: discomfort and performance anxiety.
- Children who experience discomfort when sitting and working at a table will often start to move about to relieve the discomfort.
- Being anxious about the task in hand (sometimes called performance anxiety) is the other reason children fidget.
Does the child experience discomfort? Or is the fidgeting due to performance / task anxiety?
There is an easy way to determine whether fidgeting is related to discomfort or to anxiety. Let the child engage in an activity that is enjoyable, requires lots of arm lifting and reaching to challenge postural control and does not make the child anxious.
Playing with Jenga blocks, or construction toys works well for this.
Observe the child. Does she happily sit erect for an extended period of time when doing a task that does not provoke an anxious response? Or does she also tire and start to prop herself up on one arm and shift about?
If the child happily sits erect with no fidgeting,, give the same child a drawing task and once again observe posture and fidgeting. Does this lead to fidgeting?
Checking for discomfort when sitting erect
Instruct your child to sit up straight on a stool. The height of the stool should be such that the child can sit erect with the feet flat on the floor and the hips bent to about 900.
Ask the child to count to 30 slowly. Encourage him/her to stay sitting erect for the whole time. At the end of this time ask: Did you like sitting up straight? Was it comfortable? Did it get boring?
Listen to your child's answers, but even more important watch for changes in his/her sitting posture. If a child finds it difficult and uncomfortable to sit up straight he/she will quickly revert to their habitual, more comfortable position.