[Helen Carey]

Yes, great questions! The SEM can be a bit confusing. Some researchers use the SEM equivalent to the MDC/MDD, but the preferred calculation for the MDC/MDD is MDC (95) = 1.96 × √ 2 × SEM where 1.96 is the z score associated with the 95% confidence level and SEM includes the pooled standard deviation (SD) and the ICC. Therefore, the SEM is included it the calculation, but not the absolute value. Relative to CP, we know that children in GMFCS level III are more variable in their motor performance compared to levels I and II. Therefore, it is not a surprise to see higher SEMs for outcome measures in level III compared to levels I and II.

We hope these responses help in your journey through the weeds!
Helen

[Helen Carey]

Hi,
I fear that I have created some confusion, so sorry! The Outcome Measures study guide indicates in the purpose column that the MABC-2 is a discriminative measure, but I see now that I inadvertently put that it is also criterion-referenced in the Administration column (which is an error). In the administration column, it should indicate that it is norm-referenced (because items were developed using a normative sample of children). The test is definitely a norm-referenced, discriminative measure by design. If a therapist chooses to use the test for multiple administrations over time to measure change, they would be using it as an evaluative measure, although that does not mean that the tool becomes criterion-referenced (it remains norm-referenced).

I apologize for the confusion and will correct the study guide!

Helen

[Helen Carey]

I just re-read my post and realized that after I did some cutting/pasting, this sentence ended up in the wrong play. I meant to say this in response to the Hanna article about peak and decline:

This is an important take home message…that children functioning in GMFCS levels I and II are more stable in performance over time while children functioning in the other levels have higher risks for motor decline.

[Helen Carey]

Thanks for the great discussion! The study guide info on prognosis was based on the original motor development curves article (Rosenbaum PL, Walter SD, Hanna SE, et al. Prognosis for gross motor function in cerebral palsy: creation of motor development curves. JAMA. 2002;288(11):1357-1363. doi:10.1001/jama.288.11.1357), which includes a little more detail compared to the textbook chapter. Approximately 90% of gross motor skills were achieved by the age of 5 years in the study sample. This is an important take home message…that children functioning in GMFCS levels I and II are more stable in performance over time while children functioning in the other levels have higher risks for motor decline. Also, don’t be confused with the fact that all items of the GMFM are usually achieved by typically developing 5 yo children.

Table 2 in this Rosenbaum article provides the specific ages when 90% of skills are achieved, which range from 2.7 yrs (level V) to 4.8 yrs (level I). The authors of the original article stated…”Because the GMFM-66 assessments of children reported here were specifically made without the use of aids, such as walkers or crutches, these patterns of gross motor development probably represent the lower limit of what children in each level can, on average, accomplish in gross motor function….nor do the curves show how children apply their motor function in the context of activity or participation in daily life.” Also, the article acknowledges that we can’t predict how children might perform (such as peak and decline in motor function) with therapeutic innovations, such as SDR, botox, and intrathecal baclofen.

This original article was published over 20 years ago, however, follow up research has supported the results to varying extents. Hanna S, Rosenbaum P, et.al. (2009) Stability and decline in gross motor function among children and youth with cerebral palsy aged 2 to 12 years. Developmental Medicine and Child Neurology;.51:295-302 showed that GMFCS levels I and II didn’t have a clear peak and decline, however, levels III-V peaked between 6-8 years and had a corresponding decline represented by GMFM-66 points.

Keep in mind that all of these studies are using specific study samples and not population-based data. There will likely be some variability in ages and performance due to different study samples. For example, the original motor curves were based on children in Canada. If you dive into all of the follow up research, however, you’ll find similarities across different countries where standard of care for CP is similar.

[Helen Carey]

This is a great question! Most tests fall squarely into 1 camp, but sometimes there is some ambiguity. For example, the PDMS and BOT are clearly norm-referenced and discriminative due to why and how they were designed. By definition, a norm referenced test must have a comparison sample (normative sample of children considered “typically” developing) who were administered the test and who’s scores determined the test’s distribution of scores across a bell curve. Score output is then based on this distribution across a bell curve and scores are reported in terms of scaled/standard, percentiles, etc. You are correct that discriminative tests are typically norm referenced because we need the normative data to determine cut offs for categories such as average, below average, etc.

The MABC-2 is considered a discriminative, norm-referenced measure based on test design and score output; it was designed to discriminate mild motor delays. Scores are reported at standard scores and percentiles. There is also weak evidence to show that it is responsive to changes over time, which tends to be a stronger characteristic of criterion referenced tests.

There is probably a stronger case for the DCDQ’07 (Revised) to be considered a criterion referenced test because scores are reported as cut offs for probability of DCD instead of providing a scaled/standard score. However, the 3 factors within the test have data distributed on bell curves, which is more common for norm-referenced tests. The test was developed using samples of typically developing children and those with suspected DCD (learning, attention, and movement impairments), also a more common characteristic of norm-referenced tests. I think a major difference lies in the purpose of these tests, such as to rule in a condition (DCD) vs rule out a condition (gross motor delay using PDMS, BOT). So, I do think that in some cases during clinical practice a criterion-referenced test could discriminate between typical development and a suspected motor condition.

I should probably provide a bit more clarity in the study guide, but I think the primary take away is that you should understand the purpose of the test (based on development) as that is a key factor in selecting outcome measures in clinical practice. Using tests for how they were not intended reduces the validity of testing results. For example, most norm-referenced, discriminative tests don’t have evidence of responsiveness, so probably should not be used to measure change in performance over time.

I hope this helps! Please let us know if you have any further questions.

[Helen Carey]

I agree with Jessica in terms of the best strategy for answering questions with the best response, even if you have a differing clinical opinion. I remember thinking…”that was a stupid question” several times. Also, in the absence of conclusive evidence comparing the different methods, we can’t really say that our answers are incorrect.

It is very likely that therapists will leave the test disagreeing with questions and answers, especially in areas where they have clinical expertise. Obviously, your goal is to pass the exam, so try not to get wrapped up in the quality of questions. Your knowledge and expertise makes you a more effective clinician, so try to focus on what you have learned in this journey and not get caught up in the questions themselves.

Thanks for bringing this information to our attention so we can relook at the evidence for future exams.

[Helen Carey]

Hi Juliana,
Case-control studies should include two groups that are identical EXCEPT for their outcome/disease status (one group would be the group of interest and the other a control group). An example would be: comparing a group of children with cerebral palsy with a group of identical children (such as age and gender and PMH) without cerebral palsy to examine a specific characteristic such as parenting stress.

Cohort studies should include two groups that are identical EXCEPT for their exposure status. An example would be: comparing two groups of children with cerebral palsy, but they are exposed to two different treatment strategies.

Hope this helps!
Helen and Jess

[Helen Carey]

Yes, household ambulation is an important consideration as we know short distances are much less demanding in terms of motor control and muscle strength. Individuals with MM and SCI often use different means of mobility for community vs household ambulation.

AD prescription should be based on motor function level, not lesion level, since lesion levels are not an exact science. It is possible for 2 children with MM with the same lesion level to have some differences in functional motor levels and, therefore, different orthotic and AD needs. We developed our study guides using multiple sources, not just Campbell. We tried to include evidence presented from these different sources.

Hope that helps!
Helen

[Helen Carey]

Yes, premie age is usually described by CCA (corrected chronological age) or AA (adjusted age).

[Helen Carey]

In regards to the issue with L3 levels between MM and SCI. The study guide has L3-S1 as a general group, so it seems possible for a L3 lesion due to SCI to require a bit more support, however, it will really depend on the individual’s motor function and muscle strength. Our information comes from published sources and doesn’t always capture all possible clinical variability (including an incomplete SCI). I think a good strategy is to focus on information regarding motor function and muscle strength since clinically we use that information to determine orthoses and assistive devices, not lesion levels.

Helen

[Helen Carey]

Hi Heidi,
I addressed a similar question last night in the forum that might also be helpful.

1. The perceptual action system is related to motor control; an example is motor control strategies for meeting the essential requirements for steady-state gait (including the requirements for postural control and movement).
2. I am not sure about cognitive theory? There is a strong component of cognition in motor learning which is seen in most theories and approaches/strategies (included in the study guide).
3. Yes, dynamic systems theory is the same. My reference (Shumway-Cook & Woollacott uses both terms.

Thanks!
Helen

[Helen Carey]

Hi Marie,
If I have the question correct, it states that the infant was 1 month CCA. The purpose of the question was to focus on interpretation of the TIMP and it’s predictive validity. The TIMP is most predictive of motor delay when administered around 90 days CCA, therefore, a child’s score at that age would provide the most meaningful information for clinical-decision-making. Because the child is not delayed or demonstrating atypical movement patterns or motor signs at 1 mo CCA, a HEP and follow up would provide targeted education, a follow up plan, and appropriate utilization of insurance resources. In some regions, this child might not quality for weekly OP services just because of PMH and risk factors. Your reasoning for intensity of services is not incorrect, although some might say it is over-utilization of services since the child is so young and not demonstrating delays or motor deficits at this time. It might also be stressful on the family who likely just returned home from the NICU.

Nice question!
Helen

[Helen Carey]

No audio, just written responses!

[Helen Carey]

Yes, best practice (recommendations from the American Academy of Pediatrics) says you should correct for infants born less than 37 weeks up to the chronological age of 2 (24 months).

[Helen Carey]

Hi Christine,
In the motor control and motor learning handout, I separated the motor control theories and the motor learning theories. Honestly, I have trouble sorting them out as well! I tried to provide specific motor implications for each to highlight their importance relative to clinical practice. Dynamic systems theory is the same at systems theory- I just tried to be consistent with terms from my resources (primarily the Motor Control textbook by Shumway-Cook & Woollacott). You’ll find that there is some overlap in the motor control and motor learning theories.

Family systems theory is related to family-centered care and is the view that individual and family functioning is an interactional and dynamic process. The transactional model of development is also related to family-centered care and emphasizes the reciprocal relationship between the child and and caregiving environment. The ecological model of human development is also related to family-centered care and is the role that the larger social systems have on the function of the family unit. (Effgen, 2nd Edition, p154). Yes, there is an ecological model of human development, an ecological theory of motor control, and an ecological theory of motor learning! While a bit frustrating to have 3 theories with a similar name, it kind of makes sense since the environment is such a critical factor in child/family functioning and motor control/learning. I think the best strategy will be to focus on the context of the test question to figure out what theories are related. In your study preparation, it will be a good idea to at least be able to categorize the theories into family-centered care, motor control, and motor learning.

In terms of motor control, there is currently more evidence to support the dynamic systems theory compared to the other theories, however, most still “exist.” Some theories are decades old and others are newer, but most continue to exist. The reflex theory seems to be one, however, that now has limited support. As therapists, having some knowledge about these theories helps us understand the evolution of our learning about motor control. Shumway-Cook & Woollacott feel that “…the actions of therapists are based on assumptions that are derived from theories. The specific practices related to examination and intervention used with the patient who has motor dyscontrol are determined by underlying assumptions about the nature and cause of movement. Thus, motor control theory is part of the theoretical basis for clinical practice.”

I hope that helps!
Helen

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