The purpose of this longitudinal study is to examine the ongoing interaction between the domains of cognitive and motor development in infants with neuromotor disability, and to compare outcomes of two groups of infants receiving two different types of home-based, parent-delivered physical therapy intervention, in order to determine which intervention is more effective in advancing cognitive as well as motor development. Knowledge of the effectiveness of two types of intervention will lead to improved early intervention for children with developmental disabilities, as well as future studies to examine ongoing outcomes.

This longitudinal study will examine the ongoing interaction between the domains of cognitive and motor development in infants with neuromotor disability, as well as compare differences between groups of infants receiving two types of intervention.

The specific aims for this study are:

1. To measure the changes of the head, trunk and pelvis as the primary orienting segments of the body during the achievement of sitting and the transition to crawling in infants with neuromotor disability.
2. Describe the changes in problem-solving and cognitive abilities of infants with neuromotor disability as they transition to stable sitting and then to crawling.
3. Using eye-tracking technology, quantify the evolution of focused attention in infants with neuromotor disability as the motor skills of sitting and the transition to crawling emerge.
4. Compare motor skill, visual attention and cognitive change as sitting and crawling emerge between groups of infants with neuromotor disabilities receiving two different interventions, and determine the effects of distinctly different paradigms: one that focuses simply on building motor skill, and the other that builds motor and cognition together.

This is a longitudinal study, with between group comparisons to determine the effectiveness of the intervention, and within group comparisons to determine change over time. Measures will occur in the home at baseline, at the end of month 1 of intervention, the end of month 2, the end of month 3, and at a 9 month follow-up visit, for a total of 5 measurement times. Each session will take approximately 1 hour each time. Because we want to look at the child's movement and posture, the child should be clothed in either an undergarment or a bathing suit that allows a view of their trunk, legs and arms during the 5 measurement sessions. We will video the child's movement and posture and play doing two standardized infant tests during these measurement sessions. The child will sit on the floor as independently as they can and reach for toys and move through as many developmental postures as they can (crawling, pulling to stand, moving in and out of sitting). The parent will always be next to their child during measurement sessions.

Children will participate in one of the parent-delivered interventions for 3-months after being randomized to one of two groups. Both intervention groups are parent-delivered interventions, with differing goals and differing training. Parents will be trained in one of the following approaches:

Motor-based problem solving approach or the body weight support (BWS) approach.

In both of the above approaches, parents will receive weekly, one-hour sessions at home for updates and training from a physical therapist to advance the program for individual infants. Thus, there will be a total of 12 sessions with a therapist. Each program is individualized because no two infants will have exactly the same skill set. This individualization of programs is standard practice for early intervention. Generally, the suggestions will follow standard developmental guidelines, with sequencing of skills presented in the order of normal development. Both of these approaches are currently used in early intervention for young children with developmental disabilities, but we do not know which is more effective, or if either approach is effective.

Inclusion Criteria:

• Infants with a diagnosis of a neuromotor disorder such as cerebral palsy, or a birth history and developmental history indicative of cerebral palsy (prematurity, intraventricular hemorrhage, periventricular leukomalacia) will be selected for this study. The infants will be at Gross Motor Function Classification Scale (GMFCS) levels I, II, or III, because infants at levels IV and V would be unlikely to reach the level of sitting independence to enter the study. Additional behavioral inclusion criteria are: between the ages of 9 months and 3 years at the time of entry into the study; the child should already be independent in prop sitting (sitting with arm support) for at least 1 minute, and be able to lift one arm up in sitting (after being placed in sitting) to reach for a toy placed directly in front of them without losing balance

Exclusion Criteria:

• blindness, dislocated hip, pending orthopedic or neurologic surgery which would interrupt the time period of the intervention, additional diagnosis that affects the neuromuscular system such as spina bifida. A child would not qualify for the study if sitting skills were mature. Mature sitting is operationally defined as: the ability to sit independently without using the arms for support for five minutes or more without falling; reaching for toys using both hands at once without disrupting balance; moving in and out of the sitting position independently.

No plan to make individual participant data available