Atypical development Flashcards
What is the dynamic systems theory?
Holistic approach to understanding human motor development
Includes various body systems and social environment, physical environment, and psychological environment
List the characteristics of atypical development
Abnormal tone – hypotonia, hypertonia, fluctuations, rigidity
Exaggerated, prolonged reflex behavior
Absence of normal reflexes
Lack of variability, variety, and frequency of spontaneous movement
Lack of adaptability
Lack of antigravity control
Lack of dissociation, rotation
Flexion and extension are not balanced
Persistence of asymmetry
Lack of controlled weight shifts
Lack of elongation on weight bearing side with lateral flexion on non-weight bearing side
Poor proximal stability with decreased ability to move against gravity
Prolonged fixing or limiting degrees of freedom due to poor underlying control
Abnormal postural alignment
Poor coordination and control of movement
What are positive signs for motor disorder diagnosis?
lead to increased frequency or magnitude of muscle activity, movement, or movement patterns
Examples:
Hypertonia
Chorea
Tics
Tremor
What are negative signs for motor disorder diagnosis?
insufficient muscle activity or insufficient control of muscle activity
Examples:
Weakness
Impaired selective motor control
Ataxia
Apraxia
In addition to positive and negative signs, what else can contribute to reduced function?
sensory deficits, biomechanical limitations, abnormalities of posture and balance, cognitive deficits, learning disabilities, fatigue, and decreased motivation
And, of course, the environment!
Explain weakness in context of a negative sign:
insufficient muscle activation, inability to generate normal voluntary force in a muscle or normal voluntary torque about a joint
Assessed during attempts to generate force in a single joint at one point in time
What are some different causes of weakness?
many possible causes of weakness
Weakness may be caused by dysfunction in many different parts of the neuralaxis including the cerebrum, corticospinal and bulbospinal tracts, spinal cord, lower motor neurons, neuromuscular junction, or contractile elements of muscle
With chronic weakness there may be changes in passive and active muscle properties that either perpetuate or partially counteract the weakness
more weakness continued… (2)
Normally weakness is manifest in many different postures, movements, or tasks
However, weakness may only be evident for certain joint angles, speeds of movement, or postures of other joints
Ability to generate force may deteriorate as a result of early fatigue of muscles, reduced endurance, or an inability to generate a sufficiently rapid increase in force
more weakness continued.. (3)
In presence of significant contractures or other limitations of ROM it may not be possible to identify weakness
hard to tell how much kid is trying and hard to test strength with contracture
It may not be possible to establish the level of effort exerted by the child
May not be able to test in presence of cognitive deficits or psychiatric disorders
In very young child, weakness is one possible cause of hypotonia and hypotonia may be the only clinically evident sign of weakness in a young or uncooperative child
what is reduced selective motor control?
Defined as the impaired ability to isolate the activation of muscles in a selected pattern in response to demands of a voluntary posture or movement
“Muscles in a selected pattern”: simultaneous activity level of each muscle in a group of muscles in which certain muscles may be activated while others are relaxed
What happens to cause impaired ability to have selective motor control?
the expected pattern is not achieved either due to excessive activation of muscles that would be expected to be relaxed or inability to activate muscles that would be expected to be active
Reduced selective motor control notes continued (2)
When reduced selective motor control involves decreased muscle activation, then particular muscles may be unable to generate full force when they are part of the abnormal pattern of activity
This is distinguished from weakness if the muscles are able to generate full force in other contexts
When weakness is present, it may not be possible to determine if a deficit of selective motor control exists
Reduced selective motor control notes continued (3)
Examples: activation of knee and hip flexors muscles when a child attempts to dorsiflex the ankle
These patterns are sometimes referred to as “obligate synergies”
Reduced selective motor control may manifest as abnormal postures or unusual movement patterns
Example: the child may have to adduct the shoulder in order to generate sufficient elbow extension force
What is ataxia?
Definition: inability to generate a normal or expected voluntary movement trajectory that cannot be attributed to weakness or involuntary muscle activity about the affected joints
“Trajectory” is a series of positions or joint angles over time
In some cases, may lead to decreased accuracy
Continued notes about ataxia (2)
May be present in multiple parts of the body
Leads to disorders of gait, limb, or trunk control
It may also occur only during certain types of movement
For example, there may be greater abnormality for multijoint movements or greater deficits of rhythmic movements
Deficits are not specific to particular tasks or goals
Continued notes about ataxia (3)
Specific deficits that may be seen as components of ataxia include:
Dysmetria (inaccurate motion to a target)
Dyssynergia (decomposition of multijoint movements)
Dysdiadochokinesia (lack of rhythmicity)
Continued notes about ataxia (4)
Associated with increased movement variability (think of gait)
Intention tremor
Examples: failure to adjust trunk musculature before or during reaching may lead to postural instability and poor reaching
Often associated with injury to cerebellum
Can also be seen in the context of peripheral sensory loss
What is apraxia and developmental dyspraxia ?
Apraxia: impaired ability to accomplish previously learned and performed complex motor actions that is not explained by ataxia, reduced selective motor control, weakness, or involuntary motor activity
B. Developmental Dyspraxia: failure to have ever acquired the ability to perform age-appropriate complex motor actions that is not explained by the presence of inadequate demonstration or practice, ataxia, reduced selective motor control, weakness or involuntary motor activity
Apraxia and developmental dyspraxia notes continued (2)
“Impaired ability” means that the motor acts are performed in a manner that is awkward, slow, or fails to accomplish the desired goal
“Complex motor actions” refers to actions that may have multiple components and are associated with goal oriented task performance, tool use, or gestures
putting movements together is hard for them
What are some other negative signs in childhood?
Deficits in sensory function including tactile, kinesthetic, or proprioceptive sensation
Sensory information and attention are needed to correct for errors during movement and to determine errors in the outcome
Deficits in higher-order sensory function may impair the ability to determine spatial relationships between objects and therefore can interfere with tool use, bimanual coordination or task planning
What is neglect?
Neglect may lead to inadequate effort and thus can be a cause of weakness
Neglect may also lead to inadequate practice or self observation and thereby slow learning of complex tasks
“Learned nonuse” or “developmental disregard”
What is a soft sign?
may not mean anything, but may point towards possible problems with neurologic system
Refers to a group of functional neurological findings which are general and not focal, often subtle, and may relate to faulty integration in abnormal development
They may give clues to underlying poor organization and possible CNS deficit
What are some behavioral soft signs in early diagnosis of neuromotor dysfunction?
Manifest early
Sucking, swallowing, and feeding abnormalities
Colic
Persistent irritability
Demanding behavior
Continuous gross movement and activity
Markedly limited attention span
Delayed speech with poor or repetitive expression
Withdrawn and isolated behavior
Irregular sleep habits
Repetitive movements
