Affordances refer to the interrelation between the individual's capacities and the properties of the environment, promoting the opportunity to perform an action. Thus, the home environment: adequate physical space, quality in the variation of stimuli, and diversity of toys can be affordances that facilitate motor development in the first years of life. However, the impact of this relationship before and after the 6th month of life, a period of major developmental changes, is unknown.

To compare home environment affordances and gross motor skills in two groups of infants with biological risk (2-6 months and 6-11 months) and verify the relationship between these variables in each group.

Observational, cross-sectional, and remote study. Fifty-three infants with biological risk for developmental delay (prematurity, low birth weight, neonatal intensive care unit admission) participated. Group 1: 2-6 months and 15 days (M=3.95 months; SD=23 days); and group 2: 6 months and 15 days-11 months (M=7.89 months; SD=37 days). Gross motor skills were assessed by the Alberta Infant Motor Scale (AIMS) using asynchronous home videos. The Affordances in the Home Environment for Motor Development - Infant Scale (AHEMD-IS) was applied using an online form, and the raw score of each dimension was recorded: Physical space, variety of stimulation, gross and fine-motor toys. Means comparison tests were performed for comparison between groups (test t and Mann-Whitney test, according to the distribution of each variable), and multiple linear regression (predictors: 4 dimensions of the AHEMD-IS; outcome: percentile of the AIMS) to each group, considering p≤0.05.

The groups did not show significant differences in AIMS, physical space, and variety of stimulation. In contrast, group 2 showed significantly higher results in the dimensions of gross and fine-motor toys. Group 1 showed no significant association between affordances and gross motor skills. Group 2 showed significant associations (p=0.005; r²= 0.444), in which the variety of stimulation (p=0.007) and gross-motor toys (p=0.015) explained 44.4% of the variation in the AIMS percentile.

Greater quality of stimulation at home and greater presence of gross-motor toys impacted motor skills in infants older than 6 months. These results are possible due to the fact that older infants have more motor skills and thus explore the environment more, in addition to having more toys, which possibly stimulates the motor skills assessed by the AIMS.

Identifying differences between the 2 groups, especially regarding the smaller amount of toys used at home for younger infants, and the association of variety of stimulation and skills for older infants, indicates the need to emphasize early family-oriented practices with a focus on environmental enrichment.