Hand Function 0-7 months

Original Editor - Robin Tacchetti based on the course by Pam Versfeld
Top Contributors - Robin Tacchetti, Jess Bell, Kim Jackson, Tarina van der Stockt and Ewa Jaraczewska

Introduction

Newborns have limited vision leading the majority of their motor and sensory experiences to their surrounding surfaces. In order to learn about the world around them, they use body to explore and interact. Spontaneous self-generated movements of the legs and arms provide contact and touch within their environment. These movements support proprioceptive feedback about their posture and where there limbs are in space.

Infants use their hands to serve many different purposes. During the infant stage of 0-7 months the hands function can best be utilised for:

1. gathering information about their bodies and surrounding surfaces
2. interacting with objects they encounter
3. communication purposes
4. body support and postural control

As the infant grows during this time period, each step of hand development augments the next stage. From birth to 6-8 weeks, most hand movements are spontaneous in nature. As they age from 2-6 months old, they are able to hold visual attention while exploring with their hands. Lastly, infants 6-8 months old can now manipulate and grasp objects to make things occur leading to goal directed behaviour.

Self Touching

During the period of birth to 24 weeks, infants explore with their hands learning about their face, body and surrounding surfaces. Young infants initially touch with the dorsum of their hands mainly in fists. Eventually the fist position transitions into a semi-closed position with contact being on the side of the hand and back of the fingers. Contact during this early period are brief. As infants move into the 8-12 week period, contact time is increased, exploration is increased, and finger manipulation has begun. From 12-24 weeks, palmar aspect of the hand is the contact point and touch is more complex. During this stage hand rotation occurs and fingertip and palms drag alongside surfaces.

** spontaneous movements can be affected by the support surface the infant is lying on

Spontaneous Movements

Spontaneous movements of the body help the infant bring their hands into contact with their body, surfaces and within their visual field. Once an infant focuses on their hands or caregivers, spontaneous movements decrease. Around 10 weeks old, infants can bring their hands into midline.

Different support surfaces can affect spontaneous movements of the limbs. Hard, firm surfaces for supine lying tends to place the infants lower extremities in extension with the upper extremities in abduction and elbow extension. This position provides less kicking and spontaneous movement. In contrast, a soft surface places a supine infant in more of a flexed position of the lower extremities with the upper extremities brought into midline near the mouth. In this flexed position, the hands are open and freely able to move to touch each other and the body.

** Reminder: spontaneous movements can be affected by the support surface the infant is lying on

Purpose of spontaneous movements

• muscle strength
• muscle endurance
• sensory input
• maintain steady head in response to upper extremity perturbations
• shaping of corticospinal tract

*** Preterm and infants with developmental delay have less spontaneous movements

Intentional Reaching and Grasping

3-4 months

Between 3-4 months, infants will be intentionally reaching for objects to play with especially when it is introduced at midline. Some of the characteristics of intentional reaching are listed below:

• reaching preceded by visual attention of the toy (allowing them to locate toy in space)
• hand is open at the beginning of the reach until grasp
• small, repetitive movements of the fingers provide for exploration of the toy shape and texture
• lose grasp of toy when no longer within visual field

5-7 months

Intentional reach and grasp during the 5-6 month stage is characterised by the following:

• able to maitain grasp of toy even when not within visual field
• hold the toy with one hand and use the other hand to explore with their fingers
• actions are more goal directed
• grabbing different parts of the toy by use:
  • palmar-grip or
  • thumb-to-forefinger grip
• pass toy from one hand to the other
• shake and bang toys
• when a new toy is introduced, they will drop old toy
• mouthing of toys

Resources

• http://tomt.skillsforaction.com/dev/hands/tutorials-dev-hand-function

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