The aim of the study was to derive a Polish version of the AIMS through its cultural adaptation and validation. This process was based on an analysis of intra- and interrater reliability, as well as concurrent validity, using PDMS-2.

The monitoring infant motor development allows for detecting delays and disturbances, enabling, if necessary, early therapeutic interventions to prevent further structural and functional disorders. However, the developmental assessment should be performed using standardised tools, which need to undergo cultural adaptation adapted and validation. This process is necessary to ensure their reliability in countries, cultures, populations, and languages different than initially intended.

The Alberta Infant Motor Scale (AIMS) is a diagnostic tool for the developmental evaluation of infants from the time of birth, to the period of independent walking (0-18 months), based on the observation of spontaneous motor performance [9,10]. It is based on several assumptions of the neuromaturational model and the concepts of the dynamic systems development theory. The AIMS was created in the early 1990s by Piper and Darrah, validated and standardised on the Canadian population [9,10]. Moreover, a 2014 re-evaluation of the scale noted that the normative values in this population remained stable.

The intended uses of the AIMS comprise: 1) identification of infants with motor delay, 2) providing medical professionals and parents information on motor achievements of the infant (both currently developing activities and those not observed in the infant's repertoire), 3) measurement of motor performance over time, or before and after an intervention, 4) as a research tool for the estimation of rehabilitation program efficacy in infants with motor delays .

The scale has been used (as an outcome measure) in numerous studies in healthy infants and those affected by or at risk of developmental disorders.

So far, research on the reliability and validity of the AIMS has been performed in Japanese, Chinese, Brazilian, Spanish, Thai, Greek, Dutch, Flemish and Serbian sample groups. However, there has not yet been a study conducted in any Middle European population.

The aim of the study was to derive a Polish version of the AIMS through its cultural adaptation and validation. This process was based on an analysis of the intra- and interrater reliability, as well as concurrent validity, using PDMS-2.

Inclusion Criteria:

• a gestational age between 37 and 42 weeks
• birth weight of ≥ 2500 g
• five-minute Apgar score ≥ 8.

Exclusion Criteria:

• a gestational age < 37 weeks,
• a birth weight < 2500 g,
• five-minute Apgar score < 8
• the presence of any neurological, orthopedic, genetic, metabolic, and sensory disorders.

The study included 145 healthy infants aged 0-18 months, divided into four age groups: 0-3 months, 4-7 months, 8-11 months, and older than 12 months