Drawing and handwriting involve coordination of shoulder and elbow movements to move the hands across the page and to draw long straight and curved lines. Children with movement difficulties (low muscle tone, joint hypermobility, DCD, autism) often lack shoulder strength, flexibility and coordination needed for effective control of these shoulder movements needed for drawing and handwriting.
Children with good shoulder control hold the arm close to the body when drawing and writing
The forearm is aligned more or less parallel to the long axis of the paper.
The end of the pencil points in a backwards rather than a sideways direction.
Children with poor shoulder control hold the arm away from the body when they draw or write
Children who have poor shoulder control for drawing tend to hold the arm away from the body (the shoulder is abducted) with the forearm aligned diagonally across the paper. The wrist may be bent (flexed) with the end of the pencil pointing sideways.
This position of the shoulder is tiring to maintain and the children often complain that drawing is "boring" and uncomfortable.
The little fellow on the right holds the arm away from the body with the end of the pencil pointing sideways. He mostly uses wrist movements to draw lines and changes to position of the paper to get his hand into the right position for producing a line in the desired direction.
Despite this he produces detailed and imaginative drawings but tires very quickly and needs lots of encouragement to stay on task.
Weakness and poor flexibility underlie poor shoulder control
Children who hold the arm out sideways when drawing find lifting the arm forwards with the elbow in line with the shoulder difficult and tiring. There are usually two reasons for this: poor shoulder flexibility and weakness of the shoulder flexor muscles.
A quick test for shoulder flexibility and strength
Instruct your child to hold the arms forwards at shoulder height with the palms facing upwards for 20 slow counts.
This task is easy for a child with good shoulder control and flexibility.
Children with poor control will often hunch the shoulders and find it hard work to keep the arms steady for a full 20 seconds.
Another test for shoulder flexibility
Lift your arms straight forwards and bend your elbows so that your forearms are held vertically.
Stay in this position for 20 seconds.
If your shoulder muscles have good strength and flexibility this will be quite easy to do.
Now keeping your upper arms horizontal and parallel, twist your arms at the shoulder by moving your hands sideways.
If you have good shoulder flexibility you will be able to position your forearms at 45 degrees to the vertical.
Lastly stretch your arms forwards and bend the elbows so that the upper arms are horizontal and the forearms are vertical.
Next move your arms together so that the elbows and forearms touch each other.
This movement is easy if you have good flexibility at the shoulder joint and are able to move your humerus away from the scapula.
If this movement is limited, the scapulae are drawn forwards across the chest and you will experience a stretch across the upper back.
Why do some children have poor shoulder control and flexibility?
The answer lies in the development of shoulder control for grasping and manipulation.
In young infants the default movement of the shoulder when reaching for objects is with the arm held away from the body and twisted inwards. Young infants also tend to grasp objects between using mainly the thumb side of the hand.
With lots of experience of grasping and manipulating toys, objects and tools the infant learns to position the hand more effectively for achieving their goals.
In order to get the hand into a better position to grasp and manipulate the young child needs to also learn to position the arm so that hands face each other and the whole hand can be used for grasping and manipulation.
This requires increased control over the ability to flex and rotate the shoulder as needed for the task.
Children with movement difficulties fail to acquire effective shoulder control
Children with movement difficulties tend to still position their arms with the upper arm held away from the body when using their hands for grasping and manipulating objects and using tools.
As a result they do not develop the control, strength and flexibility of the shoulder structures needed for using the hands in front of the body with ease and comfort.
Often children with poor shoulder control also lack the coordination needed to keep the trunk steady when moving the arm. This can be seen when they are drawing.
It also means that they may take up more space when working at a table.
What can be done to improve shoulder control?
A two pronged approach is helpful.
1 Exercises to improve shoulder muscle flexibility and strength