Principles of Assessment and Training Infant Sitting

Original Editor - Pam Versfeld
Top Contributors - Robin Tacchetti and Jess Bell

The Purpose of Assessment of Infant Sitting[edit | edit source]

Generally speaking the assessment of infant sitting serves one of two purposes:

Firstly, assessment is used to identify how far along the sitting developmental trajectory the infant has progressed. The Segmental Assessment of Trunk Control (SATCo) and Alberta Infant Motor Scale (AIMS) are two standardised tests that are commonly used to assess sitting progress.

Secondly, assessment serves to identify what an infant can and cannot do at the present time, why they are experiencing difficulties and what can be done to improve their sitting abilities.

The Segmental Assessment of Trunk Control (SATCo)[edit | edit source]

The SATCo is a clinical assessment of a child’s ability to maintain an upright head and trunk posture when manual support is provided at progressively lower levels of the trunk.[1][2] With the infant sitting on a bench, manual support at the shoulder girdle is used to assess head control, followed by support at the level of axillae, the inferior scapula, lower ribs, below the ribs, pelvis and finally, no support.

The child is seated on a sitting bench and the pelvis is fixed in a vertical position by a strap. The therapist supports the trunk at different levels.

For each trunk segmental level, static, active and reactive control are scored as present, absent or not tested (NT).

  • Static control is credited if the child can maintain a neutral trunk posture above the level of hand support;
  • Active control is credited if the child can maintain a neutral posture during head movement;
  • Reactive control is credited if the trunk above the support remains stable during an external perturbation (a nudge).

The SATCo has been shown to be a reliable and valid clinical measure of trunk control in infants with TD, as well as children with neuromotor disability.

Full instructions for using the SATCo are provided in the SATCo Clinical Workbook.

Alberta Infant Motor Scale (AIMS)[edit | edit source]

The AIMS assesses the maturation of an infant's gross motor skills from term (40 weeks post conception) to 18 months of age.

The AIMS consist of four subscales nl. supine, prone, sitting, standing. Each subscale has a set of items that describe increasing levels of maturation of a developmental task.

Each item is accompanied by a graph depicting the percentage of infants in the normative sample for each age category that received credit for the particular item.

Studies using AIMS normative data to evaluate its validity in different countries have shown some differences in the age at which infants achieve different items.[3][4]

The sequence of items in the sitting scale of the AIMS provides a useful reference for identifying an infant’s progress along the trajectory of unsupported sitting. They include:

Sitting with external support:


Unsustained sitting with arm support:


Pull to sit:


Sustained sitting with arm support:


Unsustained and sustained sitting without arm support:


Reach with rotation:


Transition to prone lying and 4 point kneeling:


Guidelines for assessment and intervention using a dynamic systems and task oriented approach[edit | edit source]

The assessment of sitting will usually be one part of a therapy session that starts with meeting and greeting the child, the family and other carers, and having a conversation about the family’s expectations and goals for the session.

This family-therapist conversation will then determine the developmental tasks that are selected for assessment and training during the therapy session and for planning the home programme.[5]

A dynamic systems, task oriented and intensive approach to intervention is informed by recommendations movement training and advocate in this course is informed by two sources.

The International Clinical Practice Guideline for Early Intervention for Children Aged 0 to 2 Years with or at risk for CP. [6]

The GAME protocol for early intervention.[edit | edit source]

The GAME intervention is based on the principles of active motor learning, family cantered care, parent coaching and environmental enrichment. Intervention is customized to parent goals and enrichment style and the child’s motor ability.[7][8]

The dynamic systems, task oriented and intensive training approach to intervention is informed by six ideas:

  1. Family centered care and the involvement of parents in selecting goals and providing opportunities for practice of movement skills is essential to success.[9] [10]
  2. Therapy should always starts with the infant's present abilities - what they can do at this present time moment , and how this creates an opportunity for learning to do more. [11]
  3. An emphasis on training intensity, repetition and many daily opportunities for practicing a task in a variety of contexts.[6]
  4. Self-initiated action, along with exploration of possibilities for doing things, supports and enhances motor learning.[12]
  5. Intrinisic motivation, curiosity, and the drive to explore and interact with people and objects supports learning new movement skills[13]
  6. Promoting enjoyable and meaningful social interaction and communication is central to intervention and supports learning of motor task

Emma’s story illustrates how these ideas are put into practice.[edit | edit source]

Emma was born 5 weeks preterm. At 8 weeks CA she has hypotonia, and has difficulty holding her head erect, even when her trunk is fully supported when held upright on a carer’s chest or in sitting on a carer’s lap.

This means that she is missing out on visually exploring the physical and social environment that allows her to get to know the structure of her environment, how her family members including the family dog move around, and to connect the sights and sounds coming from things that are happening around her. [14]

And because she cannot look up she does not socially connect with her siblings.

The therapist suggests to Emma’s mom that she lean back slightly with Emma’s head resting on her chest. This small change in the way her mom supports her in sitting allows Emma to easily keep her head erect and with a bit of practice she starts to look around, smile at the dog and enjoy watching her sister making funny faces.

She becomes curious about the sounds and sights around her and turns her head to locate them.

Now that she is able to hold her head up, Emma enjoys the rich visual environment provided by family life. And when she sits on her dad’s lap she is willing to put in the effort needed to keep her head erect when her dad moves his manual support lower down on her chest.

Infants learn best when actively engaged in exploring ways to achieve a goal.[edit | edit source]

A dynamic systems, task oriented approach to training movement behaviors starts with the assumption that infants only learn new skills when they actively engage in exploring their environment and try out different options for achieving their goals. [12]

Jono’s story[edit | edit source]

Jono at 10 months corrected age has recently learned to sit erect without support on a flat surface but his balance is still precarious and he easily topples over.

He is a very cautious little fellow and avoids any actions that challenge his balance. When placed in sitting on the mat he will only reach for toys that are within easy to reach.

He likes to explore new toys using both hands and his actions include vigorous shaking, banging the toy on the mat, passing it from one hand to the other and throwing toys.


Watching Jono playing with different toys shows that his ability to sit erect is enhanced by several basic postural abilities.

  • He can maintain his head and trunk erect.
  • He anticipates destabilizing forces created by moving his arms.
  • He uses vision to gather information about the position, size shape of toys needed for planning reaches.
  • He has the necessary neck, trunk and hip flexibility and strength to maintain sitting easily.

Parent goals for Jono include him becoming more mobile in sitting so that he can move to reach toys, and for him to be able to transition from sitting to prone kneeling.

In order to achieve these goals Jono must first needs to be more active in sitting, reach for toys that require him to combine weight shift and trunk leaning with his arm reaching actions. To do this Jono needs to explore reaching further without losing his balance.

Jona’s therapist and mom play a number of games that require him to reach a little further each time. To keep him engaged they play knock-the-bottle-over and stop the spinning bottle, as well as picking up and throwing a ball. These games involve repetition and have an outcome that indicates success. We also spend some time playing with large toys that are tricky to pick up and move.

Each of these games requires a slightly different set of postural responses as well as a different reaching strategy with regards to direction, speed and force of the moving arm.

Over the course of the 15 minutes that the training session lasts Jono’s ability to reach beyond arm’s length improves as he learns to integrate trunk and arm movements to extend his reach.


Jono’s story illustrates how factors within the child, the task and the environment can either constrain or promote the infant’s ability to successfully complete a task and achieve a goal.[edit | edit source]

In other words an infant's ability to perform a particular task is determined by factors within the infant (strength, flexibility, coordination, motivation, interest, level of alertness, attention abilities), the task demands (biomechanical, timing and sequencing of movements, stability and balance requirements) and the social and physical environment

Put another ways task oriented movement training within a dynamic systems framework takes as a starting point the idea that behavior is always influenced by the complex interaction between the infant, the demands of developmental task, and the environment.

In Jono’s case his timid nature and avoidance of challenging tasks is a major constraint.

Sharing ideas and figuring out solutions together[edit | edit source]

An important part of family centred therapy is to encourage carers to actively participate in figuring out ways to modify and vary training tasks and to adapt them to suite family routines and circumstances. [11]

Gugu’s story

10 month old Gugu can sit erect on a flat surface propping on her arms for a short period of time, however her balance is precarious and she easily topples over to the side. Mom’s goal is for Gugu to sit in her feeding chair for family meals and to finger feed herself.

But Gugu has difficulty staying erect in the chair and tends to fall to one side or push back against the back of the chair, causing her to slide forwards.

Together Gugu’s mom and the therapist figure out a way to use towels to provide waist level support when Gugu sits in the feeding chair. They then spend some time playing games which encourage Gugu to lean and reach forwards. They find out that Gugu really enjoys knocking empty plastic drinks bottles, tin cans and balls off the tray.

Reaching forwards brings her trunk erect for longer periods of time and stops her pushing back.

Next Gugu’s mom puts a few pieces of banana which is her favorite snack on the chair’s tray and Gugu reaches forwards to grasp it, leans back against the back of the chair and brings the banana to her mouth. Leaning against the back of the chair provides that extra bit of stability needed for her to successfully bring the banana to her mouth.

Another important aspect of family centered care is to collaborate with parents to create many opportunities to practice newly acquired abilities within the daily routine/schedule.[edit | edit source]

Remember that the key to success when training motor skills is lots and lots of varied practice. This is best achieved by providing the infant with many, many opportunities for practicing sitting in different contexts within the daily routine.[15]

It is also important for carer’s to consider how to create short periods of time within the daily routine for dedicated practice of selected tasks.[6]

Resources[edit | edit source]

References[edit | edit source]

  1. Sangkarit N, Siritaratiwat W, Bennett S, Tapanya W. Factors Associating with the Segmental Postural Control during Sitting in Moderate-to-Late Preterm Infants via Longitudinal Study. Children. 2021 Sep 26;8(10):851.
  2. Pin TW, Butler PB, Cheung HM, Shum SL. Relationship between segmental trunk control and gross motor development in typically developing infants aged from 4 to 12 months: a pilot study. BMC pediatrics. 2019 Dec;19(1):1-9.
  3. 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.
  4. 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.
  5. Baldwin P, King G, Evans J, McDougall S, Tucker MA, Servais M. Solution-focused coaching in pediatric rehabilitation: an integrated model for practice. Physical & occupational therapy in pediatrics. 2013 Nov 1;33(4):467-83.
  6. 6.0 6.1 6.2 Morgan C, Fetters L, Adde L, Badawi N, Bancale A, Boyd RN, Chorna O, Cioni G, Damiano DL, Darrah J, De Vries LS. Early intervention for children aged 0 to 2 years with or at high risk of cerebral palsy: international clinical practice guideline based on systematic reviews. JAMA pediatrics. 2021 Aug 1;175(8):846-58.
  7. Morgan C, Novak I, Dale RC, Guzzetta A, Badawi N. GAME (Goals-Activity-Motor Enrichment): protocol of a single blind randomised controlled trial of motor training, parent education and environmental enrichment for infants at high risk of cerebral palsy. BMC neurology. 2014 Dec;14(1):1-9.
  8. Morgan C, Novak I, Dale RC, Guzzetta A, Badawi N. Single blind randomised controlled trial of GAME (Goals⿿ Activity⿿ Motor Enrichment) in infants at high risk of cerebral palsy. Research in Developmental Disabilities. 2016 Aug 1;55:256-67.
  9. King G, Williams L, Hahn Goldberg S. Family‐oriented services in pediatric rehabilitation: A scoping review and framework to promote parent and family wellness. Child: care, health and development. 2017 May;43(3):334-47.
  10. An M, Palisano RJ, Yi CH, Chiarello LA, Dunst CJ, Gracely EJ. Effects of a collaborative intervention process on parent empowerment and child performance: A randomized controlled trial. Physical & Occupational Therapy in Pediatrics. 2019 Jan 2;39(1):1-5.
  11. 11.0 11.1 Baldwin P, King G, Evans J, McDougall S, Tucker MA, Servais M. Solution-focused coaching in pediatric rehabilitation: an integrated model for practice. Physical & occupational therapy in pediatrics. 2013 Nov 1;33(4):467-83.
  12. 12.0 12.1 Corbetta D, DiMercurio A, Wiener RF, Connell JP, Clark M. How perception and action fosters exploration and selection in infant skill acquisition. Advances in child development and behavior. 2018 Jan 1;55:1-29.
  13. Atun-Einy O, Berger SE, Scher A. Assessing motivation to move and its relationship to motor development in infancy. Infant Behavior and Development. 2013 Jun 1;36(3):457-69.
  14. Harbourne RT, Ryalls B, Stergiou N. Sitting and looking: a comparison of stability and visual exploration in infants with typical development and infants with motor delay. Physical & Occupational Therapy in Pediatrics. 2014 May 1;34(2):197-212.
  15. Hwang AW, Chao MY, Liu SW. A randomized controlled trial of routines-based early intervention for children with or at risk for developmental delay. Research in developmental disabilities. 2013 Oct 1;34(10):3112-23.