Table 1.

Comparison of START-Play Intervention Content With UC-EI Content, Exemplifying Constructs of START-Play, and Notable Differences^a

Example Content	UC-EI	START-Play Session	Difference
Sitting and object permanence	1. Practice sitting balance reactions on ball (isolated motor task) 2. Therapist provides seated support to constrain trunk and suggests presenting toys on tray in front of infant and modeling use of toy	1. Select activity for motor-based problem solving: finding hidden toy. Infant encouraged to shift weight, re-orient to look behind/under/in containers, thus building sitting balance in service of spatial understanding 2. Dynamic low support in sitting allows infant to re-orient and gain spatial understanding; multiple options for variable sitting support depending on problem-solving task	1. Cognitive construct selected first and is primary; movements built around cognitive construct 2. Parents taught that chair is passive and not variable. Multiple seated options, with minimal support needed, allow exploration and link motor to problem solving
Reaching and means-end	3. Presents toys in different locations for infant to reach 4. Presents toys of different shapes, colors, weight, and textures for infant to reach	3. Sets up environment so reaching a proximal object (beads) will cause distal object to move (tied to other toy) 4. Places desirable toy just out of reach but on cloth so infant has to pull cloth to get toy	3. Cognitive construct of means-end is over-arching theme in motor activities 4. Infant must solve a problem; how to reach “unreachable” toy. Cognitive is end point of motor problem.
Reaching and object affordance	5. Uses toy to have infant reach in a pattern that requires change of trunk posture	5. Several objects presented that allow combinations that are interesting, eg, small ball that fits in a tube and flies out other end, showing affordance of objects (round affords rolling, tube affords in/out)	5. Infant discovers properties and uses for objects and what motor change (various sitting and reaching options) allows the action to occur

^a START-Play = Sitting Together and Reaching to Play; UC-EI = usual care-early intervention.