DEVELOPMENTAL MEDICINE & CHILD NEUROLOGY SYSTEMATIC REVIEW
Muscle tone assessments for children aged 0 to 12 years: a
LEANNE M JOHNSTON
1 School of Biomedical Sciences, The University of Queensland, Brisbane; 2 School of Health and Rehabilitation Sciences, The University of Queensland, Brisbane,
Correspondence to Miran Goo, School of Biomedical Sciences, The University of Queensland, St Lucia, Qld 4072, Australia. E-mail: firstname.lastname@example.org
This article is commented on by Shortland on page 637 of this issue.
Accepted for publication 27th November
Published online 6th February 2018.
ATNA Amiel-Tison Neurological
COMFORT behaviour scale
COSMIN COnsensus-based Standards for
the selection of health
HINE Hammersmith Infant
NNNS Neonatal Intensive Care Unit
Network Neurobehavioral Scale
NSMDA Neurological Sensory Motor
The aim of this study was to identify and examine the psychometric properties of
muscle tone assessments for children aged 0 to 12 years.
Four electronic databases were searched to identify studies that included
assessments of resting and/or active muscle tone. Methodological quality and overall
psychometric evidence of studies were rated using the COnsensus-based Standards for the
selection of health Measurement INstruments checklist.
Twenty-one assessments were identiﬁed from 97 included studies. All assessments
were broad developmental assessments that included muscle tone items or subscales. Most
assessments (16/21) were designed for young children (<2y). Four assessments measured
resting and active tone and demonstrated at least moderate validity or reliability: the Amiel-
Tison Neurological Assessment (ATNA) at term, Neonatal Intensive Care Unit Network
Neurobehavioral Scale (NNNS), Premie-Neuro for newborn infants, and the Hammersmith
Infant Neurological Examination (HINE) for infants aged 2 months to 2 years. For children
over 2 years, the Neurological Sensory Motor Developmental Assessment (NSMDA) assesses
resting and active tone but has limited validity.
The ATNA at term, NNNS, Premie-Neuro, HINE, and NSMDA can assess
resting and active tone in infants and/or children. Further psychometric research is required
to extend reliability, validity, and responsiveness data, particularly for older children.
Atypical muscle tone is one of the most common clinical
features observed in children with neurodevelopmental dis-
orders. It is a characteristic of many conditions, for exam-
ple those with early brain injury or cerebral palsy (CP) (2.1
genetic conditions such as Down syndrome
(1.4 per 1000),
and children with Developmental Coor-
dination Disorder (5–8 per 100).
With these populations
in mind, the collective prevalence of atypical muscle tone
can be estimated to affect about 5 to 8 per cent of the gen-
eral population. This paper will focus on the intensity
attribute of tone, which ranges between hypertonia (atypi-
cally high tone) and hypotonia (atypically low tone).
Persistent hypertonia is problematic because it can restrict
movement and lead to secondary impairments such as con-
tracture, pain, limited motor development, and restricted
Persistent hypotonia produces other
issues, such as poor joint stability, poor postural alignment,
decreased activity tolerance, and delayed motor skill acqui-
Given such a large proportion of the population
experiences difﬁculties with muscle tone, accurate assess-
ment of muscle tone is essential for diagnostic, prognostic,
and treatment planning purposes.
criterion standard muscle tone assessment has been
endorsed to date.
Both neural and non-neural factors contribute to tone
and can produce atypical muscle tone. The neural compo-
nent of muscle tone represents the tonic stretch reﬂex,
which is generated when a muscle is facilitated by neural
commands from cortical and subcortical centres, spinal cir-
cuitry, a stretch reﬂex, or other peripheral inputs.
Brain dysfunction can therefore impact on regulation of
muscle tone. For example, damage to the basal ganglia,
which normally inhibits descending motor commands, may
result in higher muscle tone.
Damage to the cerebel-
lum, which normally facilitates motor commands,
result in low muscle tone. The neural component of mus-
cle tone is highly inﬂuenced by internal factors such as an
individual’s arousal state,
and external factors such as
As these factors contribute to the neu-
ral drive to muscles, the lowest muscle tone that can be
achieved is under anaesthesia when neural drive to a mus-
cle is blocked.
The non-neural component of muscle tone represents
the inherent viscoelastic properties or stiffness of muscle
660 DOI: 10.1111/dmcn.13668 © 2018 The Authors. Developmental Medicine & Child Neurology published by John Wiley & Sons Ltd on behalf of Mac Keith Press.
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