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CHAPTER II
LITERATURE REVIEW
The literature review would be represented according to the
following items:
I.
II.
Evidence based practice.
Systematic review.
III.
Cerebral palsy.
IV.
Hemiplegia.
V.
VI.
Bimanual performance.
Bimanual training.
I) Evidence based practice
Evidence-based medicine (EBM) was initially called “critical
appraisal” to describe the application of basic rules of evidence as they
evolve into application in daily practices. Evidence-based medicine is
defined as an explicit and judicious use of current best evidence in
making decisions about the care of individual patients. Evidence-based
practice is defined based on 4 basic and important events, which include
recognition of the patient’s problem and construction of a structured
clinical question, thorough search of medical literature to retrieve the best
available evidence to answer the question, critical appraisal of all
available evidence, and integration of the evidence with all aspects and
contexts of the clinical circumstances (Manchikanti, 2008).
In daily practice the need for valid information about diagnosis ,
prevention, intervention, prognosis and harm are growing .it is estimated
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that a clinician would need an answer for many questions and the answer
for such questions should be based on solid research evidence rather than
an opinion or past undocumented and untested experiences. However, in
reality the answer to these questions for the same patient usually differ
from one clinician to another even in the same situations as clinicians are
used to base their decisions on subjective rather than objective standards
(Elstein 2004).
The adoption of an evidence-based approach in medical practice will
help clinicians adopt a lifelong learning process to stay up to date with the
current literature, to overcome some of the limitations of the current
medical practice and to rationalize their clinical decision-making process,
also providing the "scientifically proven" current best diagnostic or
treatment modality to their patients (Choudhry et al., 2005).
The Shift toward Evidence Based Practice
Evidence Based Practice (EBP) requires a shift from the traditional
paradigm of clinical practice grounded in clinical experience, and
pathophysiological rationale. In the EBP paradigm, clinical expertise is
combined with integration of best scientific evidence, patient values and
preferences, and the clinical circumstances (Susan, 2007).
Evidence Based Practice is a clinical decision-making approach
critical to promote best patient outcomes and problem solving approach
in which physicians seek solution for question that arise during their day
to day clinical practice, EBP aims to apply evidence gained from the
scientific method to certain parts of medical practice and to assess the
quality of evidence relevant to the risks and benefits of treatments
(Sackett et al., 2000).
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Evidence Based Medicine involves two fundamental principles in
clinical decision-making. First, the evidence is always interpreted
together with the patient's values and preferences by weighing the
benefits and risks, and the costs associated to the treatment compared to
the alternatives. Second, the strength of the available evidence may be
variable, constituting a hierarchy of evidence on the basis of the ability of
the study to avoid systematic bias (Anttila, 2008).
Evidence Based Medicine is the integration of clinical expertise,
patient values, and the best evidence into the decision making process for
patient care. Clinical expertise refers to the clinician's cumulated
experience, education and clinical skills. The patient brings to the
encounter his or her own personal and unique concerns, expectations, and
values. The best evidence is usually found in clinically relevant research
that has been conducted using sound methodology (Sackett, 2002).
Steps of Evidence Based Medicine
According to Shaheen (2009), practicing EBM includes the
following steps (5 as model) as shown in figure (1):
1. Assessment of the patient.
2. Asking clinical questions about the patient problem.
3. Acquiring the best available evidence that answers these questions.
4. Appraisal of evidence for its validity and usefulness.
5. Applying the results of the appraised evidence to the patient.
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E B M C ycle
√
Assess
your patient
Fig. (1): Steps of Evidence based medicine (Shaheen, 2009).
Asking clinical question means to convert the patient's problem into
clinical question in a specific format as shown in figure (2), (PICO)
represents these particular components(Guidance of EFSA, 2010) where:
(P) is the patient problem or population of interest.
(I) is the intervention, independent variable or exposure.
(C) is the comparison intervention or exposure or reference intervention.
(O) is the outcome that patients look for (patient oriented outcome).
PICO question according to Moher and Tricco(2008) may be:
 Therapy Question: Concerning the effectiveness of a treatment
 Prognosis Question: Concerning outcome of a patient with a
particular condition.
 Diagnosis Question: Concerning the ability of a test to predict the
likelihood of a disease.
 Harm Question: Concerning the likelihood of a therapeutic
intervention or exposure to cause harm.
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Fig. (2): PICO question (Shaheen, 2009).
Decision making is the process by which evidence is (or is not)
applied to practice. The statement "evidence alone does not make
decisions, people do" according to Haynes et al., (2002) reflects the
integral role of the therapist in translation of evidence to practice.
Evidence is applied within the context of values and preferences of
individual patients, clinical expertise of the practitioner, and health care
resources (Guyatt et al., 2000).
Components of evidence-based decision making
Evidence Based Practice is a problem solving approach in which
solutions are sought for questions that arise during clinical practice. It is
defined as the integration of best research evidence with clinical expertise
and patient values as shown in figure (3) (Oxford Centre for evidence –
based medicine, 2009).
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Fig. (3): Components of Evidence-Based Decision (Haynes and Haines, 1998).
(1) Research evidence
It involves tracking down the best and latest evidence from
research articles that critically appraised for its validity and usefulness
before applying their results to the patient care (Richardson, 2000).
Evidence Based Practice help clinicians to keep their practice up to
date and to explain satisfactory the rationale behind their decisions. In
this way, they will ultimately provide the best care to their patients.
Because evidence relies on well-designed research studies to demonstrate
the efficacy and effectiveness of diagnostic tests, treatment strategies,
new materials, and products, the scientific literature is an essential
component for evidence-based practice (Straus et al., 2005).
The best evidence for intervention can be drawn from randomized
controlled trials (RCT) and systematic reviews of such trials. Randomized
controlled trials (RCTs) are the “gold standard” for providing evidence on
the effects of interventions (Anttila, 2008).
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(2) Clinical expertise
It refers to the clinician's cumulated experience, education and
clinical skills. It is important to rapidly identify each patient's unique
health state and diagnosis, their individual risks and benefits of potential
interventions, and their personal values and expectations. It is important
to emphasize that EBM complement experience and does not replace it
(Sackett et al., 2000).
(3) Patient value
The patient value mean the unique preferences, concerns and
expectations each patient brings to a clinical encounter and which must be
integrated into clinical decisions if they are to serve the patient (Sackett et
al., 2000).
The Hierarchy of Evidence
Evidence based practice clinician must know the strength of the
evidence found and therefore the accompanying degree of uncertainty to
make decisions about whether evidence should be applied to practice,
Figure (4) presents the classic hierarchy of evidence triangle. With each
descending level on the pyramid, the chance for bias increases
(Bhandari, 2003).
Evidence-based clinical guidelines and systematic reviews (SRs)
are at the top of the hierarchy, providing the richest source of best
evidence. Evidence obtained from at least one well-designed randomized
controlled trial (RCT) is next followed by evidence obtained from welldesigned controlled trials without randomization and from well-designed
cohort studies and case-controlled studies. Descriptive studies, evaluation
studies, and qualitative studies are generally positioned at the base of the
pyramid. Evidence generated from research is not all the same. Some
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evidence is better than others are. Whenever one searches for evidence,
he should start looking for the best available one that is obtained from the
following types of research as seen in figure (4) (Sackett et al., 2000).
1- Systematic reviews and meta-analysis.
2- Randomized controlled studies.
3- Non-randomized controlled studies.
4- Cohort studies.
5- Case control studies.
6- Case series.
7- Case reports.
8- Opinions of experts.
9- Animal research and in vitro studies.
S.Rs& metaanalysis
R.C.T.
s
Non RCT
Cohort
studies
Case control
studies
Case series
Case reports
Opinions of
Animal research and in virtro
studies
Fig. (4): Levels of Evidence. (Sackett et al., 2000).
exp expee
xxexperts
EXPERTSEXe
xperts
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The amount of evidence supporting or failing to support the
effectiveness of physical therapy for children with cerebral palsy has
increased exponentially in each of the past two decades. Reasons for this
include (1) academic progress within the physical therapy profession,
including a greater number of PhD-trained therapists and elevation of the
basic education level for therapists from a bachelor’s to a doctoral degree
and (2) factors outside of the profession, such as a greater focus on
evidence-based practice in all medical and allied health fields (Damiano,
2009).
Requirements for evidence-based physical therapy according to
Jewell (2008):
• A willingness to challenge one's assumptions.
• The ability to develop relevant clinical questions about a patient/client.
• Access to evidence.
• Knowledge regarding evidence appraisal.
• The time to make it all happen.
II) Systematic review
A systematic review (SR) is an overview of existing evidence
pertinent to a clearly formulated question, which uses pre-specified and
standardized methods to identify and critically appraise relevant research,
and to collect, report and analyze data from the studies that are included
in the review (Guidance of EFSA, 2010).
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Why systematic reviews are needed?
The explosion in medical, nursing and allied healthcare
professional publishing within the latter half of the 20th century (perhaps
20,000 journals and upwards of two million articles per year), which
continues well into the new millennium, makes keeping up with primary
research evidence an impossible feat (Mckibbon et al., 2004).
For many, this need conflicts with their busy clinical or
professional workload. For consumers, the amount of information can be
overwhelming, and a lack of expert knowledge can potentially lead to
false belief in unreliable information, which in turn may raise health
professional workload and patient safety issues (Higgins and Green,
2011).
Systematic Reviews help overcoming limitations of primary
research by testing its findings for consistency and whether they can be
generalized across populations or not. Meta-analysis in particular
increases the power and precision of estimates and treatment effects and
exposure risks. Besides the explicit methods used in SR, it limits bias and
improves reliability and accuracy in conclusions. In this way, SR and
meta-analysis can help physicians, physical therapists, health care
providers and policy makers to make informed decisions in health care
(Akobeng, 2005).
Importance of a systematic review:
The importance of systematic review is concluded for that, for busy
healthcare providers and decision makers, systematic reviews are
important as they summarize the overwhelming amount of research –
based healthcare information that is available to be read and synthesized
(Clarke, 2005).
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Systematic reviews overcome some of the bias associated with
small single trials where results may not be robust against chance
variation if the effects being investigated are small. Under Guyatt’s
leadership, the Evidence-Based Medicine Work Group published a series
of articles for the Journal of the American Medical Association between
1993 and 2000 that outlined the criteria for evaluating current evidence to
support clinical decisions. These articles formed the basis of most
existing critical appraisal tools. Acceptance for EBM has grown
substantially over the past fifteen years among nurses and other health
professionals including public health practitioners (Glasziou et al., 2004).
Advantages of a systematic review:
There are multiple advantages of systematic reviews according to
Jessani and Reid (2009):
Condensed: allowing the reader to access consolidated results of huge
volume of information.
Objective: reducing (though not eliminating) the risk of bias and error.
Balanced: studies which are identified via a thorough and systematic
search strategy.
Verifiable: incorporating transparent processes that allow the reader to
know exactly how the conclusions were reached.
Flexible: can be updated on a regular basis.
Dynamic: in identifying under-researched areas or new research
questions.
Readable: presented in a format that is easy to read and understand.
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Steps of a systematic review according to Handoll and Smith( 2003):
1. The title - framing the review question.
2. Forming the review team.
3. The protocol - deciding on and defining inclusion and exclusion
criteria, and methods.
4. Exhaustive search for material.
5. Appraisal and quality assessment of material.
6. Data extraction.
7. Summarizing and synthesis (combining the results).
8. Interpretation
Briefly, developing a SR requires the following steps as illustrated in
figure (5) according to Davies and Crombie (2006):
1. Defining an appropriate healthcare question
This requires a clear statement of the objectives of the review,
intervention or phenomena of interest, relevant patient groups and
subpopulations (and sometimes the settings where the intervention is
administered), the types of evidence or studies that will help answer the
question, as well as appropriate outcomes. These details are rigorously
used to select studies for inclusion in the review.
Fig. (5): Steps for conduction of systematic reviews (Attia et al., 2007).
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2. Searching the literature
The published and unpublished literature is carefully searched for
the required studies relating to an intervention or activity (on the right
patients, reporting the right outcomes and so on). For an unbiased
assessment, this search must seek to cover all the literature (not just
MEDLINE where, for example, typically less than half of all trials will be
found), including non-English sources. In reality, a designated number of
databases are searched using a standardized or customized search filter.
Furthermore, the grey literature (material that is not formally
published, such as institutional or technical reports, working papers,
conference proceedings, or other documents not normally subject to
editorial control or peer review) is searched using specialized search
engines, databases or websites. Expert opinion on where appropriate data
may be located is sought and key authors are contacted for clarification.
Selected journals are hand-searched when necessary and the
references of full-text papers are also searched. Potential biases within
this search are publication bias, selection bias and language bias.
3. Assessing the studies
Once all possible studies have been identified, they should be
assessed in the following ways, each study needs to be assessed for
eligibility against inclusion criteria and full text papers are retrieved for
those that meet the inclusion criteria.
Following a full-text selection stage, the remaining studies are
assessed for methodological quality (e.g. Pedro scale) using a critical
appraisal framework. Poor quality studies are excluded but are usually
discussed in the review report. Of the remaining studies, reported findings
are extracted onto a data extraction form. Some studies will be excluded
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even at this late stage. A list of included studies is then created.
Assessment should ideally be conducted by two independent reviewers.
Trials could be rated with a checklist more specific for physical
therapy intervention studies (called the Pedro scale). The Pedro scale
considers two aspects of trial quality, namely the “believability” (or
internal validity) of the trial and whether the trial contains sufficient
statistical information to make it interpretable. It does not rate the
“meaningfulness” (generalizability or external validity) of the trial, or the
size of the treatment effect.
To assess believability we look for confirmation of a number of
criteria, including random allocation, concealment of allocation,
comparability of groups at baseline, blinding of patients, therapists and
assessors, analysis by intention to treat and adequacy of follow-up. To
assess interpretability we look for between-group statistical comparisons
and reports of both point estimates and measures of variability. This gives
a total of 10 scale items. Trials are rated on the basis of what they report.
If a trial does not report that a particular criterion was met, we score it as
if the criterion was not met (guilty until proven innocent).
All but two of the Pedro scale items are based on the Delphi list,
developed by Verhagen and colleagues. The Delphi list is a list of trial
characteristics that was thought to be related to trial “quality” by a group
of clinical trial experts. The Pedro scale contains additional items on
adequacy of follow-up and between-group statistical comparisons. One
item on the Delphi list (the item on eligibility criteria) is related to
external validity, so it does not reflect the dimensions of quality assessed
by the Pedro scale. This item is not used to calculate the method score
that is displayed in the search results (which is why the 11 item scale
gives a score out of 10). This item has, nevertheless, been retained so that
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all Delphi list items are represented on the Pedro scale (Sherrington et
al., 2000).
4. Combining the results
If appropriate, the findings from the individual included studies can
then be aggregated to produce a summary estimate of the overall effect of
the intervention. Sometimes this aggregation is qualitative (i.e., individual
descriptions of the included studies), but more usually it is a quantitative
assessment using meta-analysis. Meta-analysis should only be performed
when the studies are similar with respect to population, outcome and
intervention.
5. Placing the findings in context
The findings from this aggregation of an unbiased selection of
studies then need to be discussed to put them into context. This will
address issues such as the quality and heterogeneity of the included
studies, the likely impact of bias, as well as the chance and the
applicability of the findings.
The reliability of the results of a randomized trial depends on the
extent to which potential sources of bias have been avoided. A key part of
a review is to consider the risk of bias in the results of each of the eligible
studies. A useful classification of biases is into selection bias,
performance bias, attrition bias, detection bias and reporting bias as
shown in table (1). Selection bias refers to Systematic differences
between baseline characteristics of the groups that are compared.
Performance bias refers to Systematic differences between groups in the
care that is provided, or in exposure to factors other than the interventions
of interest. Attrition bias refers to Systematic differences between groups
in withdrawals from a study. Detection bias refers to Systematic
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differences between groups in how outcomes are determined. Reporting
bias refers to Systematic differences between reported and unreported
findings. (Higgins and Green, 2011).
Table (1): A common classification scheme for bias (Adapted from
Higgins and Green, 2011).
Relevant domains in the
Collaboration’s ‘Risk of
bias’ tool
Type of bias
Description
Selection bias
Systematic
differences
between
baseline
characteristics
of
the
groups that are compared.

Sequence
generation.

Allocation
concealment.
Systematic
differences
between groups in the care
that is provided, or in
exposure to factors other
than the interventions of
interest.

Blinding of
participants and
personnel.

Other potential
threats to validity.
Detection bias Systematic
differences
between groups in how
outcomes are determined.

Blinding of
outcome
assessment.

Other potential
threats to validity.
Systematic
differences
between
groups
in
withdrawals from a study.

Incomplete
outcome data
Reporting bias Systematic
differences
between reported and
unreported findings.

Selective outcome
reporting
Performance
bias
Attrition bias
24
Method of heterogeneity in study design and quality affect the ability
to perform a meta-analysis. When study heterogeneity precludes metaanalysis, the authors of SR need to summarize findings based on the
strength of the individual studies and reach conclusions if indicated
(Wright et al., 2007).
Heterogeneity
Studies brought together in a SR will differ; any kind of variability
among studies in a SR may be termed heterogeneity. It can be helpful to
distinguish between different types of heterogeneity. Variability in the
participants, interventions and outcomes studied may be described as
clinical heterogeneity, and variability in trial design and quality may be
described as methodological heterogeneity. Variability in the treatment
effects being evaluated in the different trials is known as statistical
heterogeneity, and this is a consequence of clinical and/or methodological
diversity among the studies. Meta-analysis should only be considered
when a group of trials is sufficiently homogeneous in terms of
participants, interventions and outcomes to provide a meaningful
summary (Higgins and Green, 2011).
Meta-analysis
Meta-analysis is the use of statistical methods to summarize the
results of independent studies, it can provide more precise estimates of
the effects of healthcare than those derived from the individual studies
included in a review and allows decisions that are based on the available
evidence. It is a powerful tool for deriving meaningful conclusions from
data. However, there are situations in which meta-analysis can be more of
a hindrance than a help. Meta-analysis of poor quality studies may be
seriously misleading. If bias is present in each or some of the individual
studies, meta-analysis will simply compound the errors, and produce a
25
‘wrong’ result that may be interpreted as having more credibility.
Reasons for considering including a meta-analysis in a review according
to Higgins and Green (2011) are:
To increase power: Power is the chance of detecting a real effect as
statistically significant if it exists. Many individual studies are too small
to detect small effects, but when several are combined there is a higher
chance of detecting an effect.
To improve precision: The estimation of a treatment effect can be
improved when it is based on more information.
To answer questions: not posed by the individual studies. Primary
studies often involve a specific type of patient and explicitly defined
interventions. A selection of studies in which these characteristics differ
can allow investigation of the consistency of effect and, if relevant, allow
reasons for differences in effect estimates to be investigated.
To settle controversies: arising from apparently conflicting studies or to
generate new hypotheses. Statistical analysis of findings allows the
degree of conflict to be formally assessed, and reasons for different
results to be explored and quantified.
Limitations of traditional reviews
Traditional reviews may, for instance, be called literature reviews,
narrative reviews, critical reviews or commentaries within the literature.
Although often very useful background reading, they differ from a SR in
that they are not led via a peer-reviewed protocol and so, it is not often
possible to replicate the findings. In addition, such attempts at synthesis
have not always been as rigorous as might have been hoped (Antman et
al., 1992).Traditional reviews are rarely explicit about how studies are
selected, assessed and integrated. Thus, the reader is generally unable to
26
assess the likelihood of prior beliefs or of selection or publication biases
clouding the review process (Torgerson, 2003).
III) Cerebral palsy
Definition:
Cerebral palsy (CP) describes a group of disorders of the
development of movement and posture, causing activity limitation, that
are attributed to non-progressive disturbances that occurred in the
developing fetal or infant brain. The motor disorders of cerebral palsy are
often
accompanied
by
disturbances
of
sensation,
cognition,
communication, perception, and/or behavior, and/or by a seizure disorder
(Rosenbaum et al., 2007).
Incidence:
Cerebral palsy is a chronic disabling condition of childhood. It
occurs in 1.5/1,000 to 3/1,000 live births with spasticity as a prevalent
disabling clinical symptom. The incidence is higher in males than in
females (Volpe, 2008).
The survival of infants has improved over time but the prevalence
of cerebral palsy has remained the same with little change over the past
40 years this is thought to be due to increase in cerebral palsy within the
population of preterm and very preterm infants (Reddihiugh
and
Collins, 2003).
Etiology
Cerebral palsy is a static neurologic condition resulting from brain
injury that occurs before cerebral development is complete. Because brain
development continues during the first two years of life, CP can result
from brain injury occurring during the prenatal, perinatal, or postnatal
periods (Bass ,2000 and United Cerebral Palsy, 2005).
27
Seventy to 80 percent of CP cases are acquired prenatally and from
largely unknown causes. Birth complications, including asphyxia, are
currently estimated to account for about six percent of patients with
congenital CP, neonatal risk factors for cerebral palsy include birth
weight of less than (2,500 g), intrauterine growth retardation, intracranial
hemorrhage, and trauma. In about 10 to 20 percent of patients, CP is
acquired postnatally, mainly because of brain damage from bacterial
meningitis,
viral
encephalitis,
hyperbilirubinemia,
motor
vehicle
collisions, falls, or child abuse (Taylor, 2005).
Classification
of
cerebral
palsy
according
to
Macnair
and
Hicks(2011):
Topographical classification:
• Tetraplegia (quadriplegia): Involvement of all limbs. Arms are equally
or more affected than the legs. Many are asymmetrical (one side more
affected) and called double hemiplegia.
• Diplegia: Involvement of limbs, with arms much less affected than legs.
• Hemiplegia: Limbs on one side affected.
Classification of types of cerebral palsy:
There are several different types of CP. While some patients are
severely affected, others have only minor disruption, depending on which
parts of the brain have been damaged. The main types of CP are:
• Spastic cerebral palsy: Some of the muscles in the body are tight, stiff
and weak, making control of movement difficult.
• Athetoid (dyskinetic) cerebral palsy: Control of muscles is disrupted by
spontaneous and unwanted movements. Control of posture is also
disrupted.
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• Ataxic cerebral palsy: Problems include difficulty with balance, shaky
movements of hands or feet, and difficulty with speech.
• Mixed cerebral palsy : A combination of two or more of them .
Symptoms of cerebral palsy:
Diagnosing CP during the earliest months of life is often unreliable.
Early warning signs include poor suck, persistent fisting, delayed motor
milestones, decrease rate of head circumference growth, seizures,
irritability, toe walking and scissoring of the lower extremities (Murphy
and Such-Neibar,2003).
Children with CP present with three types of motor problems .The
primary impairments of muscle tone, balance and strength are directly
related to damage in the CNS. Secondary impairments of muscle
contracture and deformities develop over time in response to the primary
problems and musculoskeletal growth. Tertiary impairments are adaptive
mechanisms and coping responses that the child develops to adapt to the
primary and secondary problems (Nadir and Selim,2005) .
Treatment of cerebral palsy according to Wikipedia(2010):
There is no cure for CP, however, various forms of therapy can
reduce the impact of the condition by easing symptoms such as spasticity,
improving communication skills and finding other ways to do things.
Treatment may include one or more of the following: physical therapy,
occupational therapy, orthoses, speech therapy, drugs, hyperbaric oxygen,
biofeedback, surgery to correct anatomical abnormalities or release tight
muscles and botulinum toxin A.
29
- Physical therapy (PT): programs are designed to encourage the
patient to build a strength base for improved gait and volitional
movement, together with stretching programs to limit contractures.
- Occupational therapy: Helps adults and children maximize their
function, adapt to their limitations and live as independently as
possible.
- Orthotic devices: Are often prescribed to minimize gait
irregularities, control spasticity, tightness and deformities.
- Speech therapy: Helps control the muscles of the mouth and jaw,
and improve communication.
- Hyperbaric oxygen therapy: Significant enhancements were
documented showing improved vision, hearing and speech as well
as a reduction of spasticity.
- Biofeedback: Is an alternative therapy in which people with CP
learn how to control their affected muscles.
- Surgery: Usually involves one or a combination of:
o Loosening tight muscles and releasing fixed joints.
o Straightening abnormal twists of the leg bones.
o Cutting nerves on the limbs most affected by movements and
spasms.
IV) Hemiplegia
Definition:
Hemiplegia is a condition involving paralysis or partial paralysis of
one side of the body. In child or infant hemiplegic CP, there is damage to
part of the brain and this may occur in utero, at birth, or later, as a result
of accident or illness. Hemiplegia is sometimes known as hemiparesis,
meaning partial paralysis of one side of the body (CHASA, 2009).
30
The affection in Spastic hemiplegia includes the limbs, trunk and the
neck. The upper limbs are more severely affected than the lower limbs,
although this is partly because the less affected proximal part of the body
makes walking look relatively normal. The involvement of the lower limb
often becomes more apparent with ambulation. Impairment in hand
functions appears because pincer grasp of thumb, extension of wrist and
supination of the forearm are affected. Bony undergrowth of the affected
limb, when present, occurs in the first two years of life (and beyond) and
if not suitably managed, may play a part in the development of
contractures of the tendo-Achilles. Seizures occur in more than 50%,
visual field defects as homonymous hemianopia and cranial nerve
abnormalities most commonly facial nerve palsy are seen. It is seen in
56% of term infant and 17% of preterm infants (Bax et al., 2005).
Types of Hemiplegia:
With respect to CP, a distinction is made between a congenital form
of hemiplegia, when the lesion occurs before the end of the neonatal
period (within the first four weeks of life), and an acquired form, when
the lesion provoking hemiplegia occurs later, within the first three years
of life (Aicardi and Bax, 2009).
Incidence of Hemiplegia:
The prevalence of spastic hemiplegia accounted for about 0.6 per
1000 live births and it did not change significantly over time (KrägelohMann and Cans, 2009). Hemiplegic forms are the most common
expression of CP (more than 38 % of cases) and the second in terms of
frequency, after diplegia, in premature infants (around 20% of cases)
(Himmelmann et al., 2005). Congenital forms amount to 70-90% of
childhood hemiplegia, while acquired forms only amount to 10-30%
(Hagberg and Hagberg , 2000).
31
Signs of hemiparesis or hemiplegic cerebral palsy according to
Menkes and Sarnat (2000) may include:
- Unilateral paresis or paralysis with upper limbs more severely affected
than the lower limbs.
-Voluntary movements are impaired with hand functions being most
affected. Pincer grasp of the thumb, extension of the wrist and
supination of the forearm are affected.
-In the lower limb, dorsiflexion and eversion of the foot are most
impaired.
-There is increased flexor tone with hemiparetic posture, flexion at the
elbow and wrist and equines position of the foot.
- Palmer grasp may persist for many years.
- Sensory abnormalities in the affected limbs are common; sterognosis is
impaired most frequently, two point discrimination and position sense
are also affected.
These children generally have very few associated problems as
seizures, learning and behavioral problems, while communications is
almost unimpaired. Functional prognosis is good compared to other types
because one side of the body is normal. All hemiplegic children learn to
walk by the age of three. They become independent in the activities of
daily living. Seizures, mild mental retardation, learning difficulties and
behavioral disturbances may complicate the management and integration
into the society. The most common musculoskeletal problems found is
shoulder adduction and internal rotation, the elbow is flexed and
pronated, the wrist and fingers are flexed, the thumb is in the palm. The
hip is extended and internally rotated, the knee is flexed or extended, and
32
the ankle is in planter flexion. The foot is generally in varus, although
valgus deformity may also be seen. The hemiplegic side may be short and
atrophied depending on the severity of the involvement (Gordon et al.,
2003).
During symmetrical bimanual movements, there is coupling of
movements of the two extremities. With one or both of the movements
being affected, This coupling may be either advantageous or detrimental
depending on the task constraints. In tasks which involve simple non
functional symmetrical (mirror) movements of the two hands, the non
involved hand slowed down and mimicked the movement of the involved
hand, as a result, the two hands accomplished their goal together as long
as the tasks were not too complicated (Utely and Steenbergen, 2006).
Obviously for asymmetrical movements of the two hands, coupling
(such as in mirror movements) can greatly interfere with task
performance.
Tasks
typically
involving
asymmetrical
bimanual
movement (e.g. opening a drawer and manipulating its contents) are
performed sequentially in children with CP; i.e. there is poor temporal
coordination (because of the complexity and asymmetrical components of
this task, the non involved hand could not simply slow down as a
compensatory strategy) so, asymmetrical movements were disturbed
more than the symmetrical movements (Hung et al., 2004). Unlike
unilateral impairments, these bimanual coordination problems may
underlie some of the functional limitations these children experience in
activities such as dressing, eating, and playing sports, and this logic forms
the basis for new bimanual assessments (Skold et al., 2010).
33
V) Bimanual performance
Occupations can simply be described as “what we do”. “What we
do” can however be viewed from several perspectives, showing a
complex construct. From one view, occupational performance is essential
to humans as a carrier of meaningful experiences (Jonsson and
Josephsson, 2005). However, another view is that the performance of
occupations can be described as a concrete execution of tasks; “getting
something done”. The routinely performance of daily activities may
require low attention and may become more or less automatic. What we
do and how we do it depends on individual interests, values, sense of
competence and effectiveness. Further, “what we do” is also dependent
on function in bodily systems and mental and cognitive abilities as well
as physical and social environment including cultural and political
structures. Thus, human occupation and "what we do" is a complex
interplay between individual and environment and when being in focus in
research, this complexity needs attention (Kielhofner, 2008).
Hand skills are critical for interaction with the environment. Hands
allow us to act on our world through contact with our own and others
bodies and through contact with objects. The child who has a disability
affecting hand skills has less opportunity to take in sensory information
from the environment and to experience the effect of his or her actions on
the world (Exner, 2005).
Bimanual activity performance varies with activity, person and
environment:
Hand use and performance of bimanual activities is varying
depending on variables in the three aspects; activity, person and
environment. It can be assumed that a dynamical interaction between
these three aspects form the activity performance:
34
1) Activity
Guiard (1987) describes bimanual performance from the perspective
of activities. Guiard categorizes bimanual activities into three categories:
unimanual (e.g., dart throwing), bimanual asymmetric (e.g., playing the
violin), and bimanual symmetric, in which the two hands play the same
role, either in phase (e.g., rope skipping) or out of phase (e.g., rope
climbing). This classification has since been used in various contexts.
However, Guiard suggests that no activity can be proven to be truly
unimanual; for example, in dart throwing, the other hand may contribute
to postural function, influencing the performance. Thus, some activities
obviously demand the use of both hands, while in others, hand use varies
and is not always obvious.
2) Person
A person can choose how to perform an activity, based on personal
preferences and in relation to the activity itself and the environment.
Values and interests, as well as belief in what one can achieve, influence
the choices made in activity performance (Kielhofner, 2008). It can be
assumed that this is true for bimanual activities as well as other activities.
However, no literature has been found as regards how the persons own
values influence hand use. However, much knowledge has been generated
as regards the neural control of the hand. Neural control of the hand
involves several areas in the brain, working together in neural networks,
selecting and planning movement performance (Pehoski, 2006). Without
having to pay attention to and plan every movement in a task, a person
performs well known tasks in an efficient way. For example, when
opening a drawer with one hand and manipulating something in the
drawer with the other, the first hand starts, reaching out towards the
drawer, preshaping the hand in relation to the size of the handle, and the
35
second hand is starting before the first hand is finished, creating a
temporal overlap between the movements of the two hands (Hung et al.,
2004). Thus, whereas the general performance of the activity is
influenced by values and personal preferences, humans are generally not
making conscious choices about how to use the hands in well known
activities, rather it is automatically formed by neural control so, if the
neural control is impaired, hand use may not be automatic in the same
way and the way of using the hands may become an issue which demand
that the person make more conscious choices. Further, the functions of
the musculoskeletal and somatosensory systems in the arm and hand,
including range of motion, strength, and sensibility, are also crucial for
how activity performance takes form (Eliasson, 2006).
3) Environment
The environment influences activity performance in various ways,
as it may both demand particular behaviours and discourage or disallow
others (Kielhofner, 2008). The environment includes both factors that
influence all of society, such as cultural and political factors, and factors
specific to the situation in which the person performs an activity, such as
social and physical environments and the object to be handled .Social
aspects include the universal need for social acceptance as well as the
need for practical, informational, and emotional support (Christiansen
and Baum, 2005). Objects are defined by Kielhofner (2008) as “naturally
occurring or fabricated things with which people interact and whose
properties influence what they do with them”. Handling objects demands
various degrees of hand function; the physical properties of objects, such
as their size, friction, and weight, require forces of various strengths, and
the grasping and lifting actions must be adjusted in relation to the object
to produce smooth movement . Previous experiences of handling objects
36
are used to estimate what movements and forces are needed, new
information rapidly contributing to updating the information base and
adjusting the feed-forward strategy (Eliasson et al., 1995 and Forssberg
et al., 1995) .
In the personal element of the activity–person–environment
interplay, the prerequisites for hand use on the part of children with
unilateral CP differ from those of children with no dysfunction, though
the activities that they are expected to perform are largely the same as
those of children with no dysfunction. To a certain degree, children with
unilateral CP are restricted in the performance of daily activities and in
social participation, although less so than children with more severe CP.
However, little is known about how the dynamic activity–person–
environment interplay manifests itself in the presence of CP, nor are there
any studies of how people with CP view this matter (Skold et al., 2010 ).
Mandich and Rodger (2006) describe children’s activities as
possibilities to develop abilities and to become social beings.
Occupational skills can only be learned and mastered by doing.
Successful doing can help children develop a healthy sense of who they
are and what they can become. Therefore, the enabling of doing is
important. The activity performance of children differs from that of
adults. Play is central in children’s lives, though the type of play differs
according to age. In the ages of middle childhood (age 6–10 years),
structured games and organized play predominate. Interacting with peers
and following rules becomes more important. By eight to nine years
children become more interested in crafts and hobbies as well as
organized sports, it becomes more important to achieve something with
the play. Social play increases in importance, e.g., belonging to groups
and talking to friends (Case-Smith, 2005). Where as earlier in life, play is
37
more characterized by the qualities of exploring, participating, and
imitating, the play of middle childhood is more characterized by
expectations of certain behaviors. However, in the presence of restricted
mobility, play can be different, children mostly played alone or with
adults. Play with friends – either interactive or as an onlooker – was less
common. During adolescence, the child takes on increased responsibility
in activities of daily life and independence becomes more important. It is
also an important aspect to fit in with peers and to be successful in
obtaining a job (Shepherd, 2005).
Children with hemiplegic CP primarily have one well-functioning
side ‘less affected’ side of their body and one ‘more affected’ side,
evaluation of the upper limb often targets the more affected limb using
unimanual assessments. Yet clinical experience shows that children with
hemiplegic CP rarely use their impaired hand for unimanual tasks. This
hand is typically used when they need it, i.e. during bimanual task
performance. Bimanual actions are more complicated than unimanual
actions as many children with hemiplegia present with deficits in
bimanual coordination which is problematic as the movements of both
arms and hands must be coordinated temporally and spatially to complete
a task or achieve a desired goal. Independence in these tasks is achieved
using adaptive strategies to compensate for poor bimanual skills (Utely
and Steenbergen, 2006).
Unimanual impairments do not greatly impact functional
independence and quality of life because tasks such as hair combing,
teeth brushing, and drinking may effectively be performed with the
noninvolved extremity. Children with hemiplegic CP are also remarkably
adept at using their non-involved extremity alone in a compensatory
manner during tasks that typically developing children or adults would
38
normally perform bimanually. However, these compensations are highly
inefficient and take longer than performing the same tasks with two
hands. Furthermore, such compensations may be reinforced over time and
make rehabilitation more difficult therefore, rather than defining
increased unimanual use of the involved extremity as the therapeutic goal,
the goal of upper extremity intervention should be to increase functional
independence by improving use of both hands in cooperation (Charles
and Gordon, 2006).
The scales designed for the assessment of upper extremity function
in children are very few. Most of them aim to assess hand function on
request and only two; Besta scale and Assisting Hand Assessment (AHA)
are designed to directly assess spontaneous hand use. This represents a
strong limitation for assessors because, in children, performance on
request is different from spontaneous use in a natural context. Besta Scale
assess the differences between the grasp function on request (capacity)
and the spontaneous bimanual use in play and activities of daily living
(bimanual performance) and AHA is a useful tool for the assessment of
spontaneous bimanual use, but it is unable to evaluate the use of the
hands in self-care activities (Fedrizzi et al., 2012).
The discrepancy between unimanual capacity and bimanual
performance is of key interest to therapists aiming to improve functional
use of the impaired limb and enhance performance of daily activities. A
greater understanding of the relationship between unimanual capacity (i.e.
what children can do with their upper limb when asked) and bimanual
performance (i.e. how children spontaneously use their impaired upper
limb in bimanual tasks) may assist clinicians in optimizing interventions
(Sakzewski et al., 2010).
39
With many everyday tasks requiring cooperative use of both hands,
poor bimanual performance is often the greatest functional impairment
for children with hemiplegia. Careful evaluation of bimanual ability
should be an integral component of an upper limb assessment as Careful
evaluation of bimanual abilities and their progression could provide
valuable information for clinicians and researchers about how these skills
are affected by the evolving impairment. Evaluation could also assist in
determining whether the infants’ skills are different to those of older
children whose motor patterns have become established. Carefully
collected information about bimanual performance could then be used to
guide and⁄ or evaluate the effectiveness of intervention programs
(Greaves et al., 2010).
VI) Bimanual training
Bimanual training in children with unilateral CP is not new.
Historically, therapists have used a bimanual approach called bimanual
occupational therapy (BOT) in the management of motor dysfunction in
children with hemiplegia. One of the traditional therapeutic intervention
aims is to improve the hemiplegic children’s ability to use their hands
together. Previously, little research has focused exclusively on
investigating the effectiveness of bimanual interventions, or identified
specific intervention strategies and training practices that promote
bimanual hand function however, practice of activities and tasks requiring
bilateral hand use is a routine element of therapy (Eliasson, 2007).
Bimanual occupational therapy focuses on improving child’s
occupational performance (the performance of self-care, productivity, and
leisure activities) in the context of motivating, meaningful, and
purposeful bimanual activities. This has been well supported by the
40
advances in the areas of neuroscience, basic mechanisms of hand function
and more specifically, motor control and motor learning theories (Hoare
et al., 2010 and Eliasson, 2005).
Charles and Gordon (2006) developed a bimanual intervention
for children with hemiplegia named Hand Arm Bimanual Intensive
Training (HABIT), which was developed in response to the limitations of
constraint induced movement therapy (CIMT), as it is a form of
functional training that takes the advantage of the key ingredient of CIMT
(intensive practice), but focuses on improving coordination of the two
hands by introducing bimanual training activities using structured task
practice embedded in bimanual play and functional activities with
intensive practice (6h per day for 10-15 days) . It uses principles of motor
learning (practice specificity) which suggest that the most functional way
to balance the cortical activity and improve bimanual control would be to
practice bimanual activities directly, and principles of neuroplasticity
(practice-induced brain changes arising from repetition, increasing
movement complexity, motivation, and reward) (Schmidt and Lee, 2005
& Nudo, 2003) .
Gordon(2011) stated that researchers in the past decade have
started to compare the effectiveness of these two approaches. The focus
has mainly been on two key questions, namely ‘what are the strengths and
weaknesses of each?’ and ‘is the successful treatment factor is the
intensity or the
constraint?’. Fedrizzi et al., (2012) compared three
groups of children with hemiplegic cerebral palsy, treated for 10 weeks
(three hours per day,
seven days per week ; first with unimanual
modified constraint-induced movement therapy (mCIMT), second with
intensive bimanual training), and the last with standard treatment to
determine if the efficacy of mCIMT is due to the restriction of the non
41
affected arm or due to the intensity of treatment and also to find whether
similar intensive practice elicited with bimanual training without the
restraint of the unaffected hand - and using the same schedule - would
result in similar functional results gained by mCIMT.
Despite the considerable attention CI therapy has received, there
are several conceptual problems in applying it to children. First, CI
therapy was developed to overcome learned non-use in adults with
hemiplegia. However, children with hemiplegia must overcome
‘developmental nonuse’, because they may never have effectively learned
to use their involved extremity. Therefore, the approach must be modified
to be developmentally focused (Gordon et al., 2005). Second, restraining
a child’s non-involved extremity (especially with casts) is potentially
invasive. Finally, constraint-induced (CI) therapies are frequently
conducted without regard for realistic expected functional outcomes
(Sunderland and Tuke, 2005).
Hand
Arm
Bimanual
Intensive
Training
versus
Bimanual
Occupational Therapy:
Despite similarities with BOT, there are specific differences between
the therapies, including the high intensity of treatment used in hand arm
bimanual intensive therapy (6h per day for 10-15 days), use of
behavioural shaping theory; and sole reliance on environmental
adaptation for grading of activities in HABIT, rather than physical
assistance or handling of the child which are used in BOT (Hoare et al.,
2010).
42
Hand Arm Bimanual Intensive Training versus Constraint Induced
Movement Therapy:
Different approaches to training have been appeared in the last
decade such as HABIT and CIMT. All of these approaches are based on
the advances in understanding of motor control, motor learning, brain
plasticity, and development and they are intended to meet different
purposes. The intention when using HABIT is to improve the frequency
and quality of bimanual hand use. By practicing bimanual activities,
children will be more successful and thereby recognize the benefit of
using the two hands. CI therapy was developed to overcome learned
nonuse in adults with hemiplegia, but, children with hemiplegia do not
need to relearn to use the hand, they need to learn what the hand can do.
It is important to remember that it is the elicited practice, rather than
restraint, that is responsible for the improved motor performance
(Eliasson, 2007).
Impaired bimanual coordination might be amenable to treatment.
During bimanual movements, the non-involved hand could provide a
template for the involved hand when movements are either performed
sequentially or simultaneously (Utley et al., 2004). Although there is some
suggestion that initial unimanual practice with the involved hand can
transfer to improvements in bimanual coordination, principles of motor
learning emphasize the importance of task specificity in practice to
maximize learning. Thus, improved bimanual coordination might be best
accomplished by practicing bimanual skills directly (Schmidt and Lee,
2005).
Although HABIT is potentially less invasive than CIMT because
there is an absence of restraint, administering it is often more difficult for
the interventionists. Children with hemiplegia are strikingly adept at
43
using only their non-involved extremity to perform tasks for which their
typically developing peers require both hands, even if it is at the cost of
efficiency (e.g. performing tasks sequentially or using body parts as a
brace). During CIMT, the restraint forces the participant to use the
involved extremity to accomplish the task, with the drawback that the
tasks must be unimanual. HABIT tasks must be bimanual to train specific
coordination skills. In many instances, spatial and temporal discoordination associated with using the two extremities together was
observed. Often their natural tendency would be to over-compensate with
their non-involved extremity (e.g. reach into the involved extremity’s
hemi space). Although the interventionist could simply remind the child
to use the involved extremity, this strategy is less effective than desirable
as children quickly attenuate. Thus, far more attention must be provided
to the choice of activities and structuring the environment. Providing
rules before an activity, with occasional reminders of the rules (rather
than direct prompts), are far more effective because the child is asked to
verbally agree before participation. Thus, the interventionist must use
these rules and the environment as a new type of restraint (Gordon et al.,
2007).
Development of HABIT by Charles and Gordon (2006):
1) OVERVIEW
HABIT methodology focuses on:
(1) Provision of structured practice increasing in complexity.
(2) Provision of functional activities that necessitate bimanual hand use.
(3) Remaining a child-friendly intervention protocol that takes into
account children’s goals and parental involvement.
44
2) TASK SELECTION
A large bank of age-appropriate fine motor and manipulative gross
motor activities that require use of both hands was established. The
intervention is conducted in groups to provide an environment of peer
support and social interaction. Specific activities are selected by
considering the role of the involved limb in the activity. Although task
demands are graded to allow for success, children are asked to use the
involved limb in the same manner as that of the non-dominant limb of a
typically developing child. During these activities the children receive
instructions from the interventionist but also must engage in their own
active problem-solving. Task performance is recorded and both positive
reinforcement and knowledge of performance are used for motivation and
to reinforce target movements.
3) PRACTICE
Because the goal is to provide sufficient practice intensity in
performing bimanual activities, the choice of specific activities is less
important than the movements the child elicits. By engaging the child in
these activities for six hours per day, both part and whole-task practice
were elicited. The use of skilled, repetitive, structured practice as a means
of inducing neuroplastic changes in the motor cortex was viewed (Nudo,
2003 and Kleim et al., 2004). Movement deficits of the involved upper
extremity and bimanual coordination problems are determined during the
pre-intervention evaluation. Bimanual activities are selected that will
improve these movement deficits and engage the child in activities of
increasingly complex bimanual coordination. Directions specifying how
each hand will be used are provided to the child before the start of each
task to prevent use of compensatory strategies (e.g. performing the task
unimanually). For example in playing with Lego bricks, the pieces are
45
placed in two piles. The child is asked to use the appropriate hand for
grasping and using each piece. If the child attempts to use the noninvolved hand inappropriately, the task is paused and the child is
reminded of the task rules. Interventionists are instructed to avoid using
physical or verbal restraint (such as consistently urging the child to use
his/her involved hand). During performance of whole-task practice, the
activities are performed continuously for at least 15 to 20 minutes.
Targeted movements and spatial and temporal coordination are practiced
within the context of completing a task. For example, during drawing, the
objective is to complete a picture using different colored markers. The
motor components include grasping the marker, removing the cap,
positioning and stabilizing the paper all with the involved hand, and
drawing on the paper with the non-involved hand. Part-task practice
involves practicing a targeted movement exclusive of other movements. It
is analogous to ‘shaping’ in psychology and CI therapy literature
(Gordon et al.,2005). Specifically, symmetrical bimanual movements that
elicit a targeted movement are used. For example, after completing a
game with Lego bricks, children pick up pieces from the table using each
hand and place them back in a box as fast as possible. The interventionist
records the number of pieces the child can place in the box in 30 seconds.
The symmetrical task allows children to practice targeted movements (i.e.
manipulation and wrist extension) with augmented neural input from the
non-involved side (Stinear and Byblow, 2004).
4) GRADING TASK DIFFICULTY
Task difficulty is graded as performance improves by requiring
greater speed or accuracy, or by providing tasks that require more skilled
use of the involved hand and arm (e.g. moving from activities in which
the involved limb acts as a stabilizer to activities that require
46
manipulation). The progressive challenge always takes into consideration
the child’s abilities (tasks should never exceed a child’s abilities).
Interventionists alter constraints to grade tasks according to desired target
movements. For example, during the drawing (whole practice) task
described above, the number of colors to be used can be incremented and
cap removal difficulty can be graded depending on the child’s motor
capabilities and the designated target movements. Likewise, the
interventionist can ask the child to frequently change the paper
orientation. During the game of Lego (part-practice) task, spatial
constraints can be added by repositioning the box. Temporal and spatial
constraints are added by asking the child to drop the pieces into the box
individually or simultaneously. Accuracy is manipulated by decreasing
the box opening.
5) HOME PRACTICE
Parental involvement is extremely important. Parents are asked to
engage children in home practice of bimanual activities for one hour daily
during the intervention and two hours daily after the intervention. HABIT
provides a window of opportunity whereby children begin a routine of
involved-hand use in which parents/caregivers can problem solve with
staff members, with the hope that this interface with the child will
continue.
Who is this intervention suitable for?
Children must be old enough and cognizant to understand
directions and understand why they are participating. Although HABIT is
designed for children with hemiplegia, it could potentially be applied to
other populations where bimanual control is also impaired. Likewise, if it
were modified in intensity, it may be suitable for younger children
47
without the potential psychological and physical risks of CIMT (Martin
et al., 2004).
Hand arm bimanual intensive training is complementary to (rather
than a substitute for) other treatments of the upper extremity as it only
occurs during a short period. Thus even a small to moderate effect size
for such a short treatment duration represents a success. Nevertheless,
HABIT may need to be performed over a longer period or repeated
during childhood and adolescence (Gordon et al., 2007) .
To motivate children, participation must be fun. Thus, HABIT is
consistent with the emphasis on functional training and practicing
predefined goals in therapeutic environments. HABIT’s emphasis on
functional activity performance also directly addresses the modification
of the definition of CP, whereby it is considered a ‘disorder of movement
and posture causing activity limitation’ (Ahl et al., 2005 and Bax et al.,
2005).
48