Sensory-Based Motor Disorder describes a condition in which the child exhibits deficits in balance, gross motor and fine motor coordination, and the ability to perform skilled, familiar and/or novel motor actions. Along with impairments in postural control, bilateral integration, and sequencing, sensory-based motor disorders also encompass impairments in praxis. Sensory-based motor disorders manifest from deficits in either tactile, proprioceptive, and/or vestibular processing; these differ from neuro-motor disorders in which there is a specific structural/anatomical, biochemical, or electrical abnormality in the brain, spinal cord, or nerves (i.e. Cerebral Palsy, seizure disorders, gene or chromosomal abnormalities, etc.)
Dyspraxia – a form of sensory-based motor disorder in which the child experiences challenge in one or more of the three components of praxis: ideation, motor planning, and execution; all of which are necessary for skilled, functional movement patterns during novel activities/tasks.
Ideation: The ability of the brain to conceive of a sequence of unfamiliar actions
Motor Planning: The ability of the brain to organize a sequence of unfamiliar actions
Execution: The ability of the brain to carry out a sequence of unfamiliar actions, and to modify or alter the motor plan when unsuccessful during the execution of the task.
An example of the praxis skills necessary to be in place for efficient performance of a skilled activity by a younger child would be: dressing self with a new shirt.
Ideation: The child is able to formulate what to do in his/her mind before even attempting to begin the skilled action. i.e. the child conceptualizes the need to place the shirt in correct orientation, how to start the task, and what the completed task will look like.
Motor Planning: The child is able to adequately sequence the steps of the task in his/her mind in an organized manner. i.e. the child recognizes how to position self, whether arms or legs will go through the arm holes of the shirt, whether the fasteners should be manipulated before or after the shirt has been placed onto body, etc.
Execution: The child is able to execute, or carry out, this sequence of events in an organized, coordinated manner. If or when difficulty occurs that impedes success with this skilled action, then the child is also able to problem solve what went wrong in order to adapt and modify the steps of the task for a more successful experience upon completion.
An example of the praxis skills necessary to be in place for efficient performance of a skilled activity by a school-age child would be: performing a series of actions after given verbal command (i.e. playing “Simon Says” or imitating gestures for representational purposes)
Ideation: The child conceptualizes what the command looks like in his/her mind (i.e. “Put your right finger on your left shoulder” or “Pat your head with your right hand”)
Motor Planning: The child has adequate body scheme and body awareness for knowledge of how to position his/her body for planning the motor movements of the task, and is able to perform the activity/action/task according to what the motor plan entails
Execution: The child is able to execute, or carry out, this sequence of verbal commands in an organized, coordinated manner; and he/she should receive feedback from muscles and joints to the brain in order to discern whether or not the production was accurate. If inaccurate, the child should be able to recognize how to alter the actions for increased success in the future. (i.e. “I put my wrong hand on wrong body part, and am able to change this action when I attempt the command again, for success with the task in the future”)
Some examples of deficits in praxis that may be targeted through occupational therapy intervention:
Ideation Deficits: The client may have difficulty with activities such as generating novel ideas to perform with either novel or familiar objects or pieces of equipment. i.e. decreased ability to formulate ideas about variety of ways to play and interact with toys and environment (while swinging, generating novel methods of swinging – such as various planes or speeds, or swinging onto a target; while jumping on trampoline, generating novel methods of jumping – such as on bottom, on knees, onto back, and/or playing new games such as “Crack the Egg”; while riding a bike, generating novel methods – such as riding without hands, gliding without feet, dodging targets, etc.)
Motor Planning Deficits: The client may have difficulty with activities involving imitation of postures, gestures, objects, actions, or sequences of actions or events. i.e. difficulty with “Follow the Leader”, learning a new dance, imitating clap patterns, playing “Simon Says”, using objects or tools, or combining equipment for activities
Execution Deficits: The client is lacking necessary feedback after performance of an activity. i.e. difficulty with recognizing what he/she just did in order to repeat a previously executed action, difficulty identifying whether a plan or action was successful, or decreased recognition of when interfering with another client’s play