Alberta Infant Motor Scale (AIMS)

Original Editor - Padraig O Beaglaoich

Top Contributors - Padraig O Beaglaoich and Naomi O'Reilly  

Objective[edit | edit source]

The Alberta Infant Motor Scale (AIMS) is a standardised observational examination tool used to assess the maturation of gross motor skills of infants in the first 18 months post-term. The AIMS was developed as a reference guide for normal development of infants based on the age related norms of 2200 infants in Alberta, Canada.[1][2]

It can be used as a screening tool to detect and track early developmental delays.[3] [4] The tool compares the level of motor development against the expected norms for their age in four categories: prone, supine, sitting and standing.

Intended Population[edit | edit source]

Figure.1 Infant Crawling [5]

The AIMS can be used with all infants younger than 18 months to identify delays in motor skill development. It can be used to monitor the change in development over time of infants younger than 18 months who:

  • show typical development with no medical concerns
  • exhibit suspect motor development delays
  • are at higher risk of developmental delay due to adverse genetic, prenatal, perinatal, neonatal, postnatal, or environmental complications.
  • have been given a specific diagnosis that presents with immature development of motor skills (e.g., Down Syndrome, Bronchopulmonary Dysplasia).[2][3]

The AIMS should NOT be used for infants who use altered movement patterns to compensate for functional limitations (e.g., paralysis, spina bifida, hypotonia, muscle spasticity) as their unique motor development improvements may not be reflected in the AIMS.[2]

Tool Description[edit | edit source]

Figure.2 Infant Prone Push Up [6]

The AIMS is a 58-item observational scoring tool. These 58 items are divided into four position-centric sub-scales[1]:

  1. Prone (21 items)
  2. Supine (9 items)
  3. Sitting (12 items)
  4. Standing (16 items)

Equipment Required[edit | edit source]

  • AIMS Manual
  • AIMS Score Sheet and Graph
  • Examining table or other raised surface for younger infants
  • Firm mat or carpet for older infants
  • Low bench or chair for some items on the scale
  • Toys appropriate for infants younger than 18 months[2]

Set-up[edit | edit source]

The AIMS can be conducted in the home or in clinic. The assessment for younger infants can be conducted on an examining table or raised surface. For older infants, the assessment should occur on a firm mat or carpeted area of the floor.[2]

Method of Use[edit | edit source]

The assessor should familiarise themselves with the administration and scoring guidelines of the Alberta Infant Motor Scale prior to conducting the assessment. The assessment takes a maximum of 20-30 minutes to complete. The assessor observes the motor functional patterns of the patient and compares them to the scale sheet.[1][2]

Scoring[edit | edit source]

Figure 3: Alberta Infant Motor Scale (AIMS) Centile Ranks Graph.[4]

It is advised that the assessor completes the scoring after the assessment has finished. The scoring sheet is comprised of a photo and a short description of the movement to be assessed.[2] The movements begin with the most basic presentations of prone lying, supine lying, sitting, and standing and progress to more advanced movement, incrementally.[1]

During the assessment, the evaluator observes the movements of the child and scores each movement component as either “observed” or “not observed”. There is no option to score the patient on ‘emerging’ movement patterns. The patient should not be accredited for items reported by the parent/guardian. The least advanced and most advanced movements observed in a given position (prone, supine, sitting, standing) create the ‘motor window’ for the patient in that position. All movements within the motor window for each position must be recorded as "observed" (O) or "not observed" (NO). [2]

The assessor scores the patient one point for each movement that was “observed” within each motor window. The accumulative score of all four positions provides the 'total score'. The total score is recorded against the corrected gestational age of the patient on a graph of normative data for infant motor function. The graph in Figure 1 contains the percentile (5th, 10th, 25th, 50th, 75th, 90th) norms of infant motor function. The assessor determines at which percentile of motor development the patient is for their age based on the graphed normative values and records it on the scoring sheet.[1][2]

Evidence[edit | edit source]

Standardisation[edit | edit source]

The data used to develop the AIMS was taken from 2202 infants younger than 18 months who were living in Alberta, Canada between 1990 and 1992, who were assessed to determine the typical development of infants at given ages.[1]

In 2014, twenty years after the initial normative data was published, developmental norms were reassessed in 650 Albertan infants over a two year period.[7] This was due to concerns of motor development delays resulting from the widespread implementation of the 'back to sleep' campaign and due to the changes in ethnic diversity in Alberta in the 20 years since initial norms were established.[8][9] The researchers of this review reported a correlation coefficient of 0.99 between the two distinct populations, concluding that the validity of the initial research remained unchanged.[7][10]

However, some researchers have investigated the normative development of infants in various countries around the globe using the AIMS. Results from these studies have formed population-specific normative values for several of these countries, such as Netherlands[11], Brazil[12][13], Serbia[14], Korea[15], Greece[16], Poland[17], Spain[18], Thailand[19], and Taiwan[20].

Reliability[edit | edit source]

Inter-rater and Intra-rater Reliability[edit | edit source]

Table 1: The inter-rater and intra-rater reliability of the Alberta Infant Motor Scale. Adapted from Piper and Darrah (2022).[2]
Conditions 0-3 months 4-7 months 8-11 months 12+ months Total
Different assessors on a single occasion 0.9556 0.9699 0.9822 0.9588 0.9967
Different assessors across occasions - - - - 0.9891
Same assessor over time 0.9485 0.9230 0.9775 0.8585 0.9925
Different assessor over time 0.8245 0.9267 0.9352 0.8634 0.9891

The inter-rater and intra-rater reliability has been investigated in several studies. All findings support high reliability in the use of the AIMS.[2][3][21][22]

Validity[edit | edit source]

Concurrent Validity (Normal Infants) - Correlation Coefficients[edit | edit source]

Table 2: Concurrent Validity (Normal Infants) - Correlation Coefficients. Adapted from Piper and Darrah (2022).[2]
Comparisons 0-4 months 4-8 months 8-13 months Total
AIMS with Peabody 0.90 0.98 0.94 0.99
AIMS with Bayley 0.84 0.93 0.85 0.97
Peabody with Bayley 0.93 0.91 0.92 0.98

Sensitivity, Specificity and Predictive Values[edit | edit source]

Table 3: Sensitivity, Specificity, Positive Predictive Value, and Negative Predictive Value for Abnormal/Suspicious vs Normal Classification. Adapted from Darrah, Piper and Watt (1998).[3]
Age / Test Cut-Off Sensitivity

(%) (N=36)


(%) (n = 128)

+ Predictive Value


- Predictive Value


4 Months

AIMS Centile

2nd 30.6 96.9 73.3 83.2
5th 41.7 90.6 55.6 84.7
10th 58.3 82.8 48.8 87.6
16th 58.3 78.1 42.9 87.0
25th 72.2 69.5 40.0 89.9
8 Months

AIMS Centile

2nd 52.8 96.1 79.2 87.9
5th 63.9 95.3 79.3 90.4
10th 72.2 89.1 65.0 91.9
16th 77.8 85.9 60.9 93.2
25th 86.1 66.4 41.9 94.4

Resources[edit | edit source]

References[edit | edit source]

  1. 1.0 1.1 1.2 1.3 1.4 1.5 Piper MC, Pinnell LE, Darrah J, Maguire T, Byrne PJ. Construction and validation of the Alberta Infant Motor Scale (AIMS). Can J Public Health. 1992; 83: 46-50.
  2. 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 Piper MC, Darrah J, editors. Motor assessment of the developing infant. 2nd edition. St. Louis, Missouri: Elsevier, Inc., 2022.
  3. 3.0 3.1 3.2 3.3 Darrah J, Piper M, Watt MJ. Assessment of gross motor skills of at‐risk infants: predictive validity of the Alberta Infant Motor Scale. Developmental medicine & child neurology. 1998 Jul;40(7):485-91.
  4. 4.0 4.1 Albuquerque PL, Lemos A, Guerra MQ, Eickmann SH. Accuracy of the Alberta Infant Motor Scale (AIMS) to detect developmental delay of gross motor skills in preterm infants: a systematic review. Developmental neurorehabilitation. 2015 Jan 2;18(1):15-21.
  5. Flickr. Thomas Life Crawling. Available from: (accessed 20 July 2022).
  6. Flickr. Thomas Life Cutie Pie. Available from: 20 July 2022
  7. 7.0 7.1 Darrah J, Bartlett D, Maguire TO, Avison WR, Lacaze‐Masmonteil T. Have infant gross motor abilities changed in 20 years? A re‐evaluation of the Alberta Infant Motor Scale normative values. Developmental Medicine & Child Neurology. 2014 Sep;56(9):877-81.
  8. Fleuren KM, Smit LS, Stijnen TH, Hartman A. New reference values for the Alberta Infant Motor Scale need to be established. Acta paediatrica. 2007 Mar;96(3):424-7.
  9. Darrah J, Bartlett DJ. Infant rolling abilities–the same or different 20 years after the back to sleep campaign?. Early human development. 2013 May 1;89(5):311-4.
  10. Alberta Infant Motor Scale: A Clinical Refresher and Update on Re-Evaluation of Normative Data. Published October 8, 2014. Accessed July 26, 2022.
  11. van Iersel PA, la Bastide-van Gemert S, Wu YC, Hadders-Algra M. Alberta Infant Motor Scale: Cross-cultural analysis of gross motor development in Dutch and Canadian infants and introduction of Dutch norms. Early Human Development. 2020 Dec 1;151:105239.
  12. Gontijo AP, de Melo Mambrini JV, Mancini MC. Cross-country validity of the Alberta Infant Motor Scale using a Brazilian sample. Brazilian Journal of Physical Therapy. 2021 Jul 1;25(4):444-9.
  13. Valentini NC, Saccani R. Brazilian validation of the alberta infant motor scale. Physical therapy. 2012 Mar 1;92(3):440-7.
  14. Lackovic M, Nikolic D, Filimonovic D, Petronic I, Mihajlovic S, Golubovic Z, Pavicevic P, Cirovic D. Reliability, consistency and temporal stability of Alberta Infant Motor Scale in Serbian infants. Children. 2020 Mar 2;7(3):16.
  15. Ko J, Lim HK. Reliability Study of the Items of the Alberta Infant Motor Scale (AIMS) Using Kappa Analysis. International Journal of Environmental Research and Public Health. 2022 Feb 4;19(3):1767.
  16. Syrengelas D, Kalampoki V, Kleisiouni P, Manta V, Mellos S, Pons R, Chrousos GP, Siahanidou T. Alberta Infant Motor Scale (AIMS) performance of greek preterm infants: comparisons with full-term infants of the same nationality and impact of prematurity-related morbidity factors. Physical therapy. 2016 Jul 1;96(7):1102-8.
  17. Eliks M, Sowińska A, Gajewska E. The Polish version of the Alberta Infant Motor Scale: cultural adaptation and validation. Frontiers in Neurology.:1504.
  18. Morales-Monforte E, Bagur-Calafat C, Suc-Lerin N, Fornaguera-Martí M, Cazorla-Sánchez E, Girabent-Farrés M. The Spanish version of the Alberta infant motor scale: validity and reliability analysis. Developmental Neurorehabilitation. 2017 Feb 17;20(2):76-82.
  19. Aimsamrarn P, Janyachareon T, Rattanathanthong K, Emasithi A, Siritaratiwat W. Cultural translation and adaptation of the Alberta Infant Motor Scale Thai version. Early Human Development. 2019 Mar 1;130:65-70.
  20. Jeng SF, Yau KI, Chen LC, Hsiao SF. Alberta infant motor scale: reliability and validity when used on preterm infants in Taiwan. Physical therapy. 2000 Feb 1;80(2):168-78.
  21. Blanchard Y, Neilan E, Busanich J, Garavuso L, Klimas D. Interrater reliability of early intervention providers scoring the Alberta Infant Motor Scale. Pediatric Physical Therapy. 2004 Apr 1;16(1):13-8.
  22. Almeida KM, Dutra MV, Mello RR, Reis AB, Martins PS. Concurrent validity and reliability of the Alberta Infant Motor Scale in premature infants. Jornal de pediatria. 2008;84:442-8.
  23. Warren McAdams, PT, DPT. Alberta Infant motor Scale (AIMS). Available from:[last accessed 22/07/22]