Effects of a Physical Therapy Intervention on Motor Delay in Infants Admitted to a Neonatal Intensive Care Unit

Inclusion Criteria: NICU admission and qualifies for Early Childhood Clinic (NICU high-risk follow up clinic) or Early Intervention due to: * BW \<1500 grams OR * Disorders of the central nervous system * Brain injury (including but not limited to extra axial hemorrhage, any grade intraventricular or intraparenchymal hemorrhage, stroke, hypoxic ischemic encephalopathy (HIE), meningitis) * HIE includes mild, moderate, severe exam on modified Sarnat exam, both cooled and non-cooled * includes "at risk for HIE" with 10-minute Apgar \<7 plus pH\<7.15 or base deficit \>/=12. * Brain developmental abnormalities (hydrocephalus, microcephaly, cortical dysgenesis) * Cramped synchronous movements at term PMA OR * Bronchopulmonary dysplasia (BPD) defined as need for respiratory support at 36 weeks postmenstrual age in an infant born at \<32 weeks of gestation. AND * Medically stable AND able to start intervention between 34-48 weeks PMA. Exclusion Criteria: (related to inability to complete intervention, sensor placement, or clinic assessments) * open wounds, skin condition precluding sensor placement * immune deficiencies requiring protective isolation * limb reduction defects * followed primarily in another clinic (including but not limited to meningomyelocele and related conditions/trisomy 21) * bleeding disorders or ongoing need for anticoagulation * palliative or hospice care (for life limiting conditions including, but not limited to trisomy 18, 13) * known visual impairment at the time of enrollment * DCFS custody * no English-speaking caregivers * any other condition that would preclude participation in the study, as determined by the PI * previously enrolled in competing randomized trial with developmental outcome variables Each child's enrollment in the study will be approved by the child's neonatologist.