Contrasting Motor Development in Typically and Atypically Developing Babies

In this video, a comparison is made between a typically developing two-month-old baby and an atypically developing baby. The typically developing baby shows midline head control, visual tracking of objects, anti-gravity movements, and reciprocal kicking. In contrast, the atypically developing baby exhibits head turning to one side, difficulty visually tracking objects, inactivity, and less trunk control.

The typically developing baby demonstrates the ability to switch muscle groups during movements, using abdominals, neck, and back extensors. In contrast, the atypically developing baby is in a position that requires less effort against gravity, resulting in a more symmetrical appearance. The typically developing baby also shows integration of major muscle groups and confidence in movement.

During prone head lifting, the typically developing baby can lift 45 degrees with extension through the upper thoracic spine. On the other hand, the atypically developing baby struggles with lifting due to weight shifting forward towards the head. Leg position changes in the typically developing baby aid in developing head and trunk control, while the atypically developing baby remains in a newborn posture.

Observing hip positions and movement strategies, the typically developing baby demonstrates weight shifts and uses abdominals for balance, enhancing shoulder girdle strength. In contrast, the atypically developing baby relies on extending and pushing up on legs, lacking assistance in lifting the head and pushing up on arms.

In the pull to sit position, the typically developing baby maintains midline head control, showcasing expected head lag for the age. Conversely, the atypically developing baby struggles with head lag, indicating delays in motor development.

In position 4, the typically-developing baby on the left demonstrates good extension through the cervical and upper thoracic spine, using shoulder elevation and elbow flexion to assist in the maneuver. In contrast, the atypically developing baby on the right shows little activity in the cervical spine and rounding of the thoracic and lumbar spine, unable to use the shoulder girdle to stabilize the upper trunk.

During position 5, the baby on the left aligns his head with his ear directly over his shoulder, showcasing good activity of the neck extensors and the ability to hold posture with assistance. Conversely, the baby on the right struggles to achieve sustained head lifting in an upright position, requiring more support to sustain a sitting posture.

In position 6, the typically-developing baby can sustain anti-gravity extension of the neck and trunk muscles, while the atypically developing baby is unable to lift his head or activate his neck and upper thoracic extensors. The typically-developing baby utilizes muscles in the shoulder girdle to augment thoracic extension and stabilizes the trunk by moving arms and legs.

When tilted forward, the typically-developing baby demonstrates sustained and increased head and neck extension, while the atypically developing baby struggles to lift his head and extend his trunk. The typically-developing baby is on track to demonstrate fundamental control in this position by six months, emphasizing the importance of early therapy for head and trunk strength development.

In supported standing, the typically developing baby exhibits good vertical alignment from head through trunk and feet, utilizing shoulder elevation and close upper extremity positioning to sustain posture. Conversely, the atypically developing baby shows little intermittent muscle activity to maintain standing weight-bearing, collapsing and deflecting when weight is applied to his feet.