Cerebral Palsy (CP) is a neurodevelopmental condition well recognised to begin at
birth or early childhood and persisting through the lifespan (Rosenbaum P. , Paneth,
Leviton, Goldstein, & Bax, 2006). It has been defined as a group of permanent disorders
of the development of movement and postures, causing activity limitation and are often
accompanied by disturbances of sensation, perception, cognition, communication, and
behaviour, by epilepsy and by secondary musculoskeletal problems (Rosenbaum, et al.,
2006) such as muscle spasticity (Romkes & Brunner, 2002). A potential (or common)
activity limitation is the ability and coordination for walking (gait), with control
of movements and postures being affected.
According to the Cerebral Palsy Alliance, NSW (CPA, 2019), there are three types of
CP; quadriplegia (where all four limbs are affected, as well as muscles in the trunk,
face and mouth often affected), diplegia (where both legs are affected), and hemiplegia
(where one arm and leg on the same side are affected).
The description and severity of the topographical of CP description can be further
added to by including motor type as well as severity (mild, moderate, severe) as well
as further classification into presentation (Cans, et al., 2007). These are; spastic
(damage in the motor cortex affecting 70-80% of individuals and the most common form,
increased tone and spasticity with pathological reflexes), dyskinetic (damage in the
basal ganglia affecting 6% of individuals, demonstrated by uncontrolled, involuntary,
recurring movements with primitive reflex patters and varying muscle tone), ataxic
(damage in the cerebellum affecting 6% of individuals and is characterised by shaky
movements due to the loss of orderly muscle co-ordination, compromising balance and
proprioception with a predominance of low tone), and mixed, which is a combination
of the damages described above.
Gross Motor Function Classification System (GMFCS) classifies the child’s movements
such as sitting, walking, and use of mobility devices and provides a standardised
system that has been found to be valid and reliable (Oeffinger, et al., 2004). The
GMFCS describes the function of a child through self-initiated movement and the use
of assistive mobility devices. It has a simple five-level grading system that is used
to describe the function of the child with CP, starting at GMFCS-I being able to walk
without limitations to GMFCS-V requiring full assistance in a wheelchair.
As ambulation is the usual method for mobilising, many children with CP strive to
achieve any form of walking possible, whether it’s with or without an assistive device.
Gait analysis is one of the important aspects of evaluation in ambulatory children
with CP (Gupta & Raja, 2012; del Pilar Duque Orozco, et al., 2016). In order to improve
a child with CP’s gait and to be able to quantify the outcomes of intervention, it
is essential to perform an analysis before and after the intervention (Bella, Rodrigues,
Valenciano, Silva, & Souza, 2012). Access to the gold standard assessment tools such
as three-dimensional, kinetic or kinematic gait analysis (Bella, et al., 2012) may
not always be readily available or feasible in a clinical setting (Read, Hazlewood,
Hillman, Prescott, & Robb, 2003; Gupta & Raja, 2012). For this reason, many valid
and reliable observational gait analysis scales have been devised to clinically evaluate
gait without the use of such technologies.
Read et al., (2003) developed the Edinburgh Visual Gait Score (EVGS), a scale for
observational gait analysis, which comprises of 17 parameters for each lower limb
and evaluates across six sites (trunk, pelvis, hip, knee, ankle and foot). Each gait
phase is analysed in the frontal, sagittal and transverse planes and the anatomical
sites are evaluated for movement through video observation (Bella et al., 2012). Scoring
uses a 3-point ordinal scale, with scores ranging from 2, 1, 0, 1, and 2, the highest
score being 34. When the segment is marked 0, it determines a normal score. When there
is a 1, it means a moderate deviation from normal in either direction (appropriate
to the plane e.g. left or right, flexion or extension), and 2 relates to a marked
deviation, therefore a higher score relates to a more severe deviation or abnormality
of gait.
The EVGS is a valid, robust, reliable and easy-to-use observational gait analysis
scale to measure of gait quality in CP (Read, Hazlewood, Hillman, Prescott, & Robb,
2003; Robinson L. W., Clement, Herman, & Gaston, 2017) and is a quick and easy gait
assessment tool to use in a clinical setting where gait laboratories are not accessible
(Thomai & Gita, 2017). The EVGS is shown to correlate with the Gait Profile Score
and the GMFCS (Robinson L. W., et al., 2015), two relevant and valid measures relating
to CP. The scale has stringent instructions to ensure reliability. Its agreement and
validity with three-dimensional gait analysis have been documented (del Pilar Duque
Orozco, et al., 2016) and was noted to be 52-73%. The developers of EVGS reported
a score reduction of 4 on each limb (compared to pre-intervention score) as an improvement
and as the minimum change in score required that would be indicative of change, not
merely related to observer variation (Read et al., 2003).
The essential properties of an observation scale are validity, reliability, and ability
to detect change (Gupta & Raja, 2012). Responsiveness is the ability of a tools detection
of change due to an intervention or over time. Thomai and Gita (2017) found the EVGS
to be sensitive enough to note changes in gait after two months of physiotherapy intervention
in children with CP. Due to the nature of spasticity and the effect it has on gait
in children with CP, the ability to consciously and continuously differ or correct
gait pattern is severely reduced, resulting in a nonchanging pattern of gait. Improvements
to gait could then be attributed to intervention, or regression of gait could be attributed
to poor intervention or physical changes.
Ankle-foot orthotics (AFOs) are the typical prescription of lower extremity orthoses
for the management of lower limb deformities that often occur with CP. AFOs are found
to; support normal joint alignment and mechanics, provide variable range of motion
(ROM) when appropriate, facilitate function (Brodke, et al., 1989; Knutson & Clark,
1991; White, Jenkins, Neace, Tylkowski, & Walker, 2002), stabilise the ankle / foot
complex (Buckon, Jakobson-Huston, Moor, Sussman, & Aiona, 2004), enable a continuous
Achilles / gastrocnemius stretch (Boyd, Pliatsios, Starr, Wolfe, & Kerr Graham, 2000),
and prevent contractures of the Achilles / gastrocnemius from developing (Morris,
2002; Hainsworth, Harrison, Sheldon, & Roussounis, 2007). Along with joint alignment,
other improvements that may be seen through the use of AFOs are the improvement in
walking efficiency (Rethlefsen, Kay, Dennis, Forstein, & Tolo, 1999), and improvement
in gait function (Westberry, et al., 2007).
Sensomotoric orthotics (SMotO) provide a different approach to the management of gait
and spasticity in children with CP. The SMotOs are created to ‘activate and deactivate’
muscles by increasing or decreasing individually placed point specific pressure on
musculotendinous structures in the foot, meaning the information that is transmitted
by the sensors for the control of muscle activity is changed (Ohlendorf, 2013). Depending
on these individual pressure bumps’ height and placement, the muscles can be activated
or restricted by making use of the regulation circuit (Ohlendorf, 2013). It has been
proposed that information is sent by afferent feedback pathways in order to reduce
the activity of over-active muscles through inhibition, which in turn facilitates
an increase in the activity of weaker muscles (Ludwig, Quadflieg, & Koch, 2013). Given
the physiology of ascending muscle chains, the reaction will not only affect the single
muscle targeted, but influence the complete chain of movement and positively impact
malposition (Ohlendorf, 2013).
Due to the paucity of literature on the direct impact of the SMotO on the neurologically
affected sensorimotor system, the proposal of muscle activity and inhibition may only
be demonstrated through clinical evidence and supposition. Because of the nature of
spasticity and the effect it has on gait in children with CP, the ability to consciously
and continuously differ or correct gait pattern is severely reduced, resulting in
a nonchanging pattern of gait. Therefore, this cross-sectional cohort study aims to
compare the effect of wearing SMotO to AFOs and to barefoot, on gait pattern in children
with CP by using the EVGS.