Foot Deformities In Cerebral Palsy Henk Willemsen Monique Beek St Petersburg May 2004

Goals of Presentation Provide you with knowledge about : Priorities of normal gait Common footdeformities in CP Orthosis used Five gait patterns in CP Complex problem: activities and disorders (shortening of the muscles, deformities) are in conflict. Example: Shortening of the muscles requires a orthosis but may limit the child in running. EVO: Blocking the plantarflexion can hinder the child in play on the floor.

Find a good orthotist!

Five priorities of Normal Gait Stability in stance Clearance of the foot in swing Appropriate pre-positioning of the foot in swing Adequate step length Conservation of energy According to James Gage there are five priorities in normal gait. Valgus / varus; balance in a dynamical situation; being able to stand on one leg. A stable base of support is a basic condition for walking & standing. Equinus alone is not an indication for correction. Conservation of energy by fine tuning the cooperation between eccentric and concentric contractions Video: Gilette; principles of Pathalogic Gait, part I

Orthotics are used to: Prevent & correct joint deformities / shortening of muscles Stimulate functional training Increase functions in activities daily live Gain efficiency in walking Use of orthosis in functional activities (like walking) has preference above use in static conditions (using night splints). In static conditions the muscle tension has to be increased constantly to acquire lengthening of the muscle. Dynamic stretching (standing frame, walking) – static stretching (night splint). ISPO: dynamic correction is better than static Prescribing orthotics: set goals, talk them over with parents and child, this makes evaluation possible, results in realistic expectations. Long-lasting pressure / load during growth, in equinus, equinovarus or equinovalgus leads tot secondary deformities in the mid and fore foot joints. Broadening of the fore foot, narrowing of the heel as a form of adaptation to the equinus. Correction of the foot gets more difficult. Deformity of the articular facets makes complete correction impossible near the end of growth.

Common Foot Deformities / Shortening of Muscles Equinus or pes calcaneus Valgus or varus calcaneus Eversion (valgus calcaneus- pes planus, talonaviculair subluxation – abduction forefoot – hallux valgus) Inversion (varus calcaneus – pes cavus – adduction forefoot) Equinus = spitsvoet, pes calcaneus = hakvoet, flatfoot = pes planus Treatment of shortened M. Gastrocnemicus and / or M. Soleus by means of AFO is controversy. Mild equinus in young children (up to 6) who can walk / stand can be corrected by means of serial casting. Lengthening of the muscles and spasm-reducing effect (possible due to less sensory input), temporary: ± 3 months. Valgus deformation often in combination with equinus: conservative treatment: orthosis, calcaneus in neutral position, medial pressure on calcaneus and correction forefoot abduction. Varus deformation: less common; conservative treatment: correction forefoot adduction & varusposition calcaneus. Often caused by hyperactivity of the M.Tibialis anterior and or weak peroneal muscles.

Three point correction Horizontal plane Pressure on lateral side calcaneus Lateral side metatarsal 5. Medial side: distal of calcaneus Frontal plane Lateral side calcaneus Mid fibula Medial side above malleolus tibia Example: valgusfoot Video: Gilette; principles of Pathalogic Gait, part II

Gait pattern 1: Weak dorsiflexion Initial contact on forefoot, full contact in stance phase without hyperextension, insufficient dorsiflexion in swing Young children often fall Varus or valgus deformity: Semi-orthopaedic shoe or SMAFO Older children learn to compensate by lifting their leg higher. Insufficient dorsiflexion of the foot, often caused by weakness of M.Tibialis Anterior, sometimes in combination with shortening / hypertonic M. Gastrocnemicus. Sometimes, at the end of growth, a transfer from the m.Tibialis posterior to the Peroneus brevis is done. C-1200 are seldom used.

Supramalleolar Orthosis (SMAFO) Corrects the ankle position; mainly used in valgus deformation Allows full plantarflexion and dorsiflexion. Indications • Flexible varus/valgus ankle positions during gait • Footflat at initial contact due to mild plantarflexion tone. • Pronation/supination positions of the forefoot. Contra-indications • High plantarflexion tone. • Extreme varus/valgus ankle positions due to high spasticity. • Decreased ankle range of movement or limited dorsiflexion. Benefits Allows first rocker (plantarflexion moment) and second rocker (dorsiflexion moment) in stance phase. Often made from polypropylene plastic.

Gait Pattern 2: Hyperextension in midstance & full contact in stance Initial contact on forefoot, full contact in stance phase with hyperextension knee Hinged AFO Rigid AFO in case of severe varus deformity Abnormal activity M.Gastrocnemicus and Soleus. Hyperextension knee may result in secondary instability of the knee. Hyperextension of the knee without shortened muscles is not an indication for operation. Risk of flexion pattern when m.gastrocnemicus is to weak / insufficient.

Hinged Ankle-Foot Orthosis (Hinged AFO) Allows some ankle movement. A Hinged Ankle-Foot Orthosis (AFO) is similar in design to the Fixed AFO, but allows some ankle movement. Indications • Presence of mild plantarflexion tone but dorsiflexion range of movement. • Presence of dorsiflexor weakness. • Presence of ankle flaccidity requiring support. Contra-indications valgus instability or short M. Gastrocnemicus & M.Soleus • Lack of dorsiflexion range of movement. • Inability to achieve plantargrade without midfoot deformity. • Weak quadriceps. Benefits • Provides plantarflexion resistance and allows dorsiflexion to the pre-determined angle. • Allows the three rockers in stance phase to be controlled. polypropylene plastic

Rigid Ankle-Foot Orthosis (Rigid AFO) Correction equinus Equinus & valgusdeformity: Rigid AFO (pp or carbon) May be used to stimulate knee flexion. Indications • Presence of plantarflexion tone. • Presence of ankle flaccidity requiring support. • Presence of mild knee hyperextension or flexion in gait that can be corrected by immobilising the ankle. Benefits • Provides plantarflexion resistance. • Indirectly affects knee hyperextension or flexion positions in gait. May be used to stimulate knee flexion: quadriceps strength should be enough. Foot plate can end behind metatarsal heads to allow roll-over during gate, or it can be extended to the end of the toes for increased support / inhibition of flexion and clawing of toes. It can be slightly lifted to decrease hypertonicity. Often made from polypropylene plastic.

Correction of knee (hyper)extension in stands phase by using a rigid AFO. Position leg at terminal swing Position of the leg at initial contact. The Ground Reaction Force is behind the ankle and initiates plantar flexion. The use of a rigid AFO result in a GRF, initiating flexion of the knee. According to the Newton's Law of Gravitation, any two objects with masses attract each other. The gravitational force acted upon an object by the earth is called gravity or weight of the object. Since we always have contact with the ground due to this gravity there always is an interaction between our bodies and the ground. According to the Newton's Law of Reaction, there is an equal and opposite reaction to every action. In other words, the action to the ground is always accompanied by a reaction from it. This reaction force from the ground is called the ground reaction force.

Gait Pattern 3: Hyperextension in midstance incomplete contact in stance Initial contact on forefoot, incomplete contact in stance phase with hyperextension knee Rigid AFO (positioned in slight dorsiflexion) Limited knee-extension in terminal swing. Prolonged activity M. Vastus Lateralis in terminal stance, to keep knee-extension and compensate limited propulsion of M. Gastrocnemicus and M. Soleus. Risk of lengthening Achilles tendon: weak M. Soleus; flexion pattern. EVO: take care that knee-extension is still possible in terminal swing

Gait Pattern 4: Hip & Knee-flexion in midstance Incomplete footcontact in stance More knee-extension in midstance: FRO or EVO Strengthening exercises of extensors (glutei, quadriceps) Hemiplegic children: threatening orthopaedic disorders: shortening of psoas, hamstrings, gastrocnemicus, joint deformities, high energy cost for walking. Correction by using FROs is only possible when there is sufficient strength to extend the hips en put the centre of gravity in front of the knee. Causes: Hyperactivity m.gastrocnemicus and medial hamstrings, combination of bodyweight and muscle activity results in knee-flexion. or Weakness of m.gastrocnemicus and soleus in combination with hyperactivity m. psoas and hamstrings, resulting in a flexion pattern.

Floor Reaction Orthosis FRO Correct knee-flexion to knee-extension Contra-indications • Medio-lateral instability of the knee. • Insufficient Quadriceps strength. Benefits • Provides independent ambulation whilst preventing knee flexion in stance • Polypropylene plastic or laminate. A laminated FRO is stronger than plastic.

The FRO uses ground reaction forces to create positive knee extension ( or knee flexion moments). The ground reaction force is manipulated by setting the ankle plantarflexion/dorsiflexion angle. The anterior tibial pad helps to apply these forces. Knee-extension: center of gravity from the body has to be in front of the knee.

Gait Pattern 5 Flexion Knee and full footcontact in midstance Persisting flexion in hip and knee in midstance. Child is mainly standing on quadriceps; often weak gastrocnemicus. Bad prognosis for keeping the possibility of walking; knee problems EVO Insufficient extension round the knee, often also weak hipextension.

Loose Ends Internal rotation hip in terminal swing, often in combination with adduction. Hyperactivity / shortening hamstrings Kissing knees Atrhrogeen cause Stiff-knee gait Stiff knee gait: hyperactivity or shortening M. Rectus Femoris causes insufficient knee flexion in pre-swing. No footclearence in initial swing. Compensation through circumduction.

Exercise ! Daily Full Range of Motion & stretching The child should do as much as she can by herself (active is better than passive!) Strengthening of weak muscles ! Promote (sport) activities Exercising should be fun Make instruction sheets for the parents ! Stretching: After relaxing the muscles (warmth), slowly but steady until the end of the motion, should not be painful: increase muscle tone. Duration: small muscle groups 10 – 40 sec , big muscle groups some minutes (Ferrrari & Cioni) Collagen contractures: difficult to stretch; at least 6 – 8 hours a day. Splints for the night and ortheses work better than stretching Active exercising helps better than passive; ortheses work better than night splints

Find a good orthotist!