The TOMT assessment protocol provides the therapist with a comprehensive description of the progressive segmental levels of control of sitting (Rachmani et al 2015), starting with control of the head when supported upright to independent sitting with good control of reaching and transitions to prone and prone kneeling.
Identifying the segmental level of control of sitting allows the therapist to select training activities that will extend and expand the infant's ability to sit, maintain trunk and head stability and interact with the social and physical environment.
The assessment of sitting progresses through 3 basic levels
Sitting with trunk support: assessment of the infant's ability to keep the head erect and steady when supported around the trunk.
Sitting with pelvic support: assesses the ability of the infant to maintain the trunk erect and stable, as well as balance and control the the trunk when reaching, when provided with support around the pelvis.
Active independent sitting: assesses of the infant's ability to maintain balance and reach in all directions, as well as start to initiate transitions to prone and prone kneeling.
Planning your assessment
Your observation of the infant, as well as the information from caregivers, will usually provide the information about which segmental level of assessment is appropriate for the infant.
Start with activities that the infant can do successfully, and progressively add more difficult tasks.
If the infant has difficulty performing a task, adapt the task or change the environment to allow the infant to succeed. This will provide clues as to which aspect of the task is limiting the infant's ability to perform the task.
Assessment tasks at 3 levels
Rachwani, J., Santamaria, V., Saavedra, S. L., & Woollacott, M. H. (2015). The development of trunk control and its relation to reaching in infancy: a longitudinal study. Frontiers in Human Neuroscience, 9, 94. http://doi.org/10.3389/fnhum.2015.00094
Saavedra, S. L., van Donkelaar, P., & Woollacott, M. H. (2012). Learning about gravity: segmental assessment of upright control as infants develop independent sitting. Journal of Neurophysiology, 108(8), 2215–2229. http://doi.org/10.1152/jn.01193.2011