Introducing Orthotic Management in Ambulant Cerebral Palsy
Top Contributors - Ewa Jaraczewska, Jess Bell, Tarina van der Stockt and Kim Jackson
Introduction
Children with cerebral palsy who are classified as Gross Motor Function Classification System (GMFCS) Levels I, II and III can achieve varying degrees of independent ambulation. Their mobility can be enhanced through the tailored prescription of lower-limb orthotics. Carefully selected orthotics can optimise gait mechanics, help with balance, minimise energy expenditure during ambulation and, ultimately, help increase a child's functional abilities.[1]
This article provides a brief recap of cerebral palsy, focusing on foot conditions and gait. It then introduces the orthotist's process for prescribing and fitting lower-limb orthoses for ambulant children with cerebral palsy.
Cerebral Palsy
"Cerebral palsy is a group of permanent disorders of the development of movement and posture, causing activity limitations attributed to the non-progressive disturbances that occurred in the developing foetal or infant brain."[2]
If you would like to refresh your knowledge of cerebral palsy, please see: Cerebral Palsy Aetiology and Pathology and Cerebral Palsy Introduction.
Gross Motor Function Classification System
The Gross Motor Function Classification System (GMFCS) categorises children with cerebral palsy into five levels based on their self-initiated gross motor function.[3] Children with a GMFCS of Levels I, II and III can achieve some degree of independent mobility:[4]
Level I: able to walk without limitations
Level II: can walk with limitations (e.g. balance, endurance limitations)
Level III: can walk using a hand-held mobility device (may use additional support, such as wheeled mobility, for longer distances, outdoors)
If you would like to learn more about the GMFCS generally and Levels IV and V, please see: Gross Motor Function Classification System - Expanded and Revised (GMFCS-ER).
Gait Patterns in Cerebral Palsy
Gait patterns observed in children with cerebral palsy can be caused by different impairments, including spasticity,[5] muscle weakness, range of motion limitations, contractures, and leg length discrepancies.[6] The type of gait pattern relates to the type of cerebral palsy (e.g. unilateral vs bilateral spastic cerebral palsy).[7]
Common gait patterns in cerebral palsy include: (1) true equinus, (2) jump gait, (3) apparent equinus, and (4) crouch gait.
The following video describes these types of gait in more detail. You can also learn about different types of gait in cerebral palsy in this optional Physiopedia article: Classification of Gait Patterns in Cerebral Palsy.
Foot Development in Children
A child's foot is still relatively underdeveloped around age of six months.[6] At birth, arches are not present in the foot. Instead, the medial longitudinal arch develops during the first decade of life.[9] Arches might not be seen when children aged three to eight years old stand or weight bear through their feet.[10] However, by the time individuals reach 18 years of age, their foot structure will typically appear fully formed and mature on imaging studies.
Clinical relevance: between the ages of six months to about ten years, there is an opportunity to maintain and prevent further deterioration of foot structure with orthotics. "After the age of eight, nine, or ten, then it's much more difficult to change from an orthotic point of view and generally, we might be looking for the assistance of orthopaedics." -- Donna Fisher[6]
Foot Changes in Cerebral Palsy
A range of foot conditions are associated with cerebral palsy, including:
- pronated foot: subtalar joint medial rotation and flattening of the arch
- cavovarus foot: elevated longitudinal arch (cavus), hindfoot varus, plantarflexion of the first ray, prominent lateral malleoli, and forefoot adduction (toes can be seen on the inside)
- escape valgus: compensatory movement to enable the foot to be flat on the ground. This compensation is driven by a tight Achilles tendon and it can alter the structure of the foot. The hindfoot shifts into valgus and the midfoot collapses
- valgus deformity: hindfoot / midfoot driven issue that can be associated with Achilles tendon tightness or collapse of the medial arch
- rocker bottom foot: a secondary condition characterised by a convex, rocker-bottom appearance of the foot. It can be caused by Achilles tendon tightness or collapse of the medial arch
- varus deformity: generally a forefoot / midfoot driven deformity that can be difficult to control
- combination: varus deformity on one foot and valgus or rocker bottom deformity on the other foot
General Referral Process for Orthotic Management
Multidisciplinary (MDT) team members initiate a referral to the orthotist when indicated. For children with cerebral palsy, a paediatrician or physiotherapist usually triggers the referral. A referral to the orthotist might be indicated when additional support is required for the child's development or to enhance rehabilitation interventions (e.g. to provide protection, improve mobility and stability, and optimise energy efficiency during functional tasks).[6]
The following information should be included in the referral: the patient's medical history, their current status, GMFCS level, and the proposed goal of the orthotic intervention. Once they receive a referral, orthotists will complete an assessment. They then fit the orthosis, review and reassess.[6]
Referrals to an orthotist should be made as soon as possible, as the appropriate orthotic device can provide support and stability, prevent contractures and improve mobility. [6] Goal setting is key: an orthotist, along with the MDT, will help to clearly map out the child's journey for the child's caregivers
Orthotics Assessment
Children with cerebral palsy all present very differently. Therefore, a comprehensive assessment is required to achieve the best orthotics outcome. This assessment includes a detailed medical history, functional assessment, clinical examination, and gait analysis. The orthotist will aim to identify any compensatory mechanisms the child with cerebral palsy has developed.
The orthotics assessment includes several key components. One of these is the evaluation of active and passive joint range of motion, which requires the assessor to consider any relevant precautions and ensure that tests are standardised.[7]Additionally, a strength assessment is typically conducted [7] and muscle tone is also evaluated using the Modified Ashworth Scale.
The assessment also involve evaluating limb length discrepancies, which can be particularly relevant for children with hemiplegic cerebral palsy. These discrepancies tend to increase with age and can lead to a range of complications, including scoliosis, limping gait, musculoskeletal problems, and pain.[11]
Finally, the orthotics assessment include general observations about the individual's overall condition and abilities. This can involve evaluating hand control, speech, swallowing function, as well as observing how they interact with their parents, siblings, and medical professionals.[6]
Dynamic Assessment
The dynamic assessment includes the following aspects:
- level of mobility and gait pattern: observation of the gait cycle in the sagittal and coronal planes and observation of joint angles at different stages of the gait cycle at different levels. if you would like to review the gait cycle, please see: The Gait Cycle
- sitting and pulling to stand (small children)
- floor mobility, including getting up off the floor
- pain
- instability
- balance
- history and risk of falls
- foot, knee and hip position during walking
Compensation Mechanisms
Children with cerebral palsy may employ various compensation mechanisms during walking to adapt to their condition. These adaptations can include muscle co-contraction, a plantar-flexed foot at initial contact or a shorter step on the affected side.[12]
Raising the center of mass on the non-affected lower extremity is also a compensation strategy used by children with cerebral palsy. By doing so, they increase the amount of energy transferred to the affected leg.[12]
Orthotic Prescription
"The key to building an effective orthosis is comprehending the musculoskeletal system and its internal and external forces."[13]
When deciding if and what type of orthosis to prescribe, several questions must be answered before making a final decision. The following questions must be considered:[6]
- which joints are affected?
- is there a specific foot, knee, or hip issue or an issue involving a combination of all lower limb structures?
- what type of functional deficits does the child present with?
- what is the child's gait pattern?
- is the child stable or unstable in standing?
- does the child need protection when moving around to prevent them from falling and tripping?
- does the child need protection from a structural issue at their knees, hips, and feet?
- what are the functional goals?
Drivers of Deformity
When assessing a child with cerebral palsy, the orthotist will consider what is driving the deformity in order to decide on the correct orthotic prescription and design.This may involve identifying whether the underlying cause of the deformity is mechanical, such as tibial bowing. The orthotist must also assess if there are any biomechanical problems at play, such as compensation for knee or hip position.[6]
Increased muscle tone can contribute to the deformity. For example, if a child has spastic cerebral palsy, they may experience spasticity and resulting shortening of the gastrocnemius or soleus, leading to escape valgus in the foot.[6]
The orthotist will consider whether muscle weakness or hypotonicity is contributing to excessive movement, which can lead to a range of complications including deformities.[6] By understanding what is driving these issues, the orthotist can provide targeted interventions to address the root cause of the problem.
"If we can distinguish this, then it is easier to decide on the correct prescription and design of the orthosis" -- Donna Fisher
Types of Orthotics
Ankle foot orthoses are often prescribed to help improve the gait of ambulatory children with cerebral palsy.[14] "The correct orthosis can be life-enhancing at different stages and prevent issues in adulthood"[6] There are different types of orthotics, insoles, flexible AFOs, jointed AFOs, dynamic and rigid AFOs.
Orthotic insoles
Orthotic insoles can be custom made or off-the-shelf.
Flexible ankle foot orthoses (AFO)
This can be custom or off-the-shelf:[6]
- off-the-shelf AFOs are one-size-fits-all
- can be used in combination with an insole to protect the foot
- off-the-shelf AFOs are often more accepted by adolescents than custom-made AFOs
It provides some flexibility. The aim with the AFO is to resist plantar flexion and allow dorsiflexion
The prescription criteria for jointed AFOs typically include conditions such as drop foot (flaccid or equinus), as well as correctable range of motion at the foot and ankle, and if there is NO tendency towards valgus or varus in the foot.
Jointed ankle foot orthoses (AFO)
The jointed AFO offer dynamic support by allowing movement into both dorsiflexion and plantarflexion at the ankle. They also provide more control over valgus and varus foot deviations.
Jointed AFOs can be bulkier and more difficult to fit into shoes compared to other types of AFOs. Additionally, they may produce noise as the joints move.
Jointed AFOs are typically recommended for individuals with sufficient ankle range of motion who tend to experience foot valgus or varus, or those with crouch gait who require dorsiflexion stops.[6]
Dynamic ankle foot orthoses (DAFO)
A DAFO is a type of hybrid orthotic device that combines the benefits of a traditional AFO with additional features. The DAFO includes a supra malleolar (SMO) device, which is placed inside an AFO shell. The SMO device helps to protect and control the midfoot region. But, due to its structure and components, a DAFO can be somewhat bulky and may pose difficulties when donning and doffing the orthosis.[6]
Rigid ankle foot orthoses
A rigid AFO is a type of orthotic device that is typically recommended for children with cerebral palsy with certain pathologies. These include tightness in the Achilles tendon, tendency to valgus or varus deformities, excessive dorsiflexion or if the child has slight tendency to flexion at the knee. [6]
Resources
- Use of the Gross Motor Function Classification System to Optimize Rehabilitation Management of Children with Cerebral Palsy
- Effects of Ankle Foot Orthoses on the Gait Patterns in Children with Spastic Bilateral Cerebral Palsy: A Scoping Review.
References
- ↑ Rodda J, Graham HK. Classification of gait patterns in spastic hemiplegia and spastic diplegia: a basis for a management algorithm. Eur J Neurol. 2001 Nov;8 Suppl 5:98-108.
- ↑ Sadowska M, Sarecka-Hujar B, Kopyta I. Cerebral Palsy: Current Opinions on Definition, Epidemiology, Risk Factors, Classification and Treatment Options. Neuropsychiatr Dis Treat. 2020 Jun 12;16:1505-1518.
- ↑ Nylén E, Grooten WJA. The stability of the Gross Motor Function Classification System in children with cerebral palsy living in Stockholm and factors associated with change. Phys Occup Ther Pediatr. 2021;41(2):138-49.
- ↑ Paulson A, Vargus-Adams J. Overview of four functional classification systems commonly used in cerebral palsy. Children (Basel). 2017 Apr 24;4(4):30.
- ↑ Hägglund G, Hollung SJ, Ahonen M, Andersen GL, Eggertsdóttir G, Gaston MS, Jahnsen R, Jeglinsky-Kankainen I, Nordbye-Nielsen K, Tresoldi I, Alriksson-Schmidt AI. Treatment of spasticity in children and adolescents with cerebral palsy in Northern Europe: a CP-North registry study. BMC Neurol. 2021 Jul 12;21(1):276.
- ↑ 6.00 6.01 6.02 6.03 6.04 6.05 6.06 6.07 6.08 6.09 6.10 6.11 6.12 6.13 6.14 6.15 Fisher D. Introducing Orthotic Management in Ambulant Cerebral Palsy Course. Plus, 2024.
- ↑ 7.0 7.1 7.2 Sarathy K, Doshi C, Aroojis A. Clinical Examination of Children with Cerebral Palsy. Indian J Orthop. 2019 Jan-Feb;53(1):35-44.
- ↑ Cerebral Palsy Foundation. Why Do Gait Patterns Matter? Learn More About Bilateral Gait. Available from: http://www.youtube.com/watch?v=3YSlIQUlUUs [last accessed 03/09/2024]
- ↑ Uden H, Scharfbillig R, Causby R. The typically developing paediatric foot: how flat should it be? A systematic review. J Foot Ankle Res. 2017 Aug 15;10:37.
- ↑ Jarman M. Stages of a child's foot development (2018). Available from https://pediatricfootankle.com/childs-foot-development/ [last access 24.08.2024]
- ↑ Kim HS, Son SM. Limb Length Discrepancy and Corticospinal Tract Disruption in Hemiplegic Cerebral Palsy. Children (Basel). 2022 Aug 10;9(8):1198.
- ↑ 12.0 12.1 Fonseca ST, Holt KG, Fetters L, Saltzman E. Dynamic resources used in ambulation by children with spastic hemiplegic cerebral palsy: relationship to kinematics, energetics, and asymmetries. Physical Therapy 2004; 8(4): 344-354.
- ↑ Miccinilli S, Santacaterina F, Della Rocca R, Sterzi S, Bressi F, Bravi M. Efficacy of Lower Limb Orthoses in the Rehabilitation of Children Affected by Cerebral Palsy: A Systematic Review. Children (Basel). 2024 Feb 6;11(2):212.
- ↑ Everaert L, Papageorgiou E, Van Campenhout A, Labey L, Desloovere K. The influence of ankle-foot orthoses on gait pathology in children with cerebral palsy: A retrospective study. Gait Posture. 2023 Feb;100:149-156.