Orthotics for ‘beginners’! Or how not to fail your FRCS questions In orthotics 

What are Orthoses? An orthosis is a device that is externally applied or attached to a body segment and that facilitates or improves function by supporting, correcting or compensating for skeletal deformities or weakness. DHSS (1980)

NOMENCLATURE Like orthopaedic surgery many devices named after individuals or places – creates confusion....  In the 1960’s American Academy of Orthopaedic surgeons suggested standard reproducible terminology of orthoses. Described by the joint or region of the body it encompasses.

Hence Upper limb: Spine: S = shoulder C = cervical E = elbow T = thoracic W = wrist L = lumbar H = hand S = sacroiliac Lower limb: H = hip K = knee A =ankle F = foot

Commonly used A.F.O………ankle foot orthosis K.A.F.O……Knee ankle foot orthosis T.L.S.O……Thoracic lumbar sacral orthosis Unfortunately...... D.A.F.O…..’Dynamic’ ankle foot orthosis S.A.F.O….Silicone ankle foot orthosis F.F.O….. Functional foot orthosis

Ideal characteristics Effective Lightweight Cosmetically acceptable Easy to put on (don) and take off (doff) Comfortable

Aims of Lower Limb Orthoses Correct and/or prevent deformity Provide a base of support Facilitate training in skills Improve efficiency in gait Improve FUNCTION

To improve efficiency of gait “5 prerequisites for efficient gait” – GAGE Stability of the stance limb. Clearance of the swinging limb. Appropriate position at terminal swing. Achieving adequate step length. Conservation of energy expenditure. These are often limited or non existent in neurological conditions

To correct and/or prevent deformity Dependent upon assessment, if the joints are of a flexible nature, then the orthosis will be used to correct/reduce the rate of deformity as the child grows Whereas fixed deformities can only be accommodated within the orthosis, and require surgical intervention to improve the position of the limb and reduce forces.

How do A.F.O.’s work in the lower limb? Controls or eliminates ankle and sub-talar motion By controlling distal joints one can alter the g.r.f. and effect more proximal joints (coupling) Therefore if placed in a slightly dorsiflexed position the g.r.f. moves posterior to knee joint resulting in flexion of the knee (ski boot)..

Coupling Joints rarely act in a solitary fashion But in unison Concept of affecting one joint by position of another = coupling Influences stability. Each level should be assessed, but also in conjunction with joints above and below.

Probably best lower limb example of coupling

Simple Ground reaction force

Mechanics of an AFO For a fixed ankle AFO

‘Trade – offs’ using A.F.O.’s in C.P. POSITIVE Restricts undesirable motion Improves ability to stand and take steps Helps toe clearance NEGATIVE Can be cumbersome & heavy May make ramps and stairs harder May be uncomfortable Draws attention

Types of A.F.O’s Rigid Ankle Hinged Ground Reaction DAFO

Rigid A.F.O.

Hinged A.F.O.

D.A.F.O’s The debate rages on………………….. Designed out of a therapy need for increased control with stability…WITH some movement. (Nancy Hilton) Fabricated from very thin flexible polypropylene. Controversy still surrounds it’s neurophysical approach due to lack of solid scientific research.

DAFO’s and tonic reflexes 1. Four tonic reflex movements of the foot can be elicited in normal infants and in some older children with cerebral palsy. 2. The disappearance of these tonic reflexes with growth appears related to maturation of the central nervous system. 3. These reflexes are of orthopaedic interest in that they may, by their occasional unopposed action, cause deformity. 4. It is suggested that these slow tonic movements represent a summation of many instantaneous reflexes, and that these instantaneous reflexes are distally located trigger mechanisms that initiate balancing reactions.

D.A.F.O.’s Cast in neutral, or as near as possible position. Provides increased foot ‘control’ without excessive control at ankle complex. Keeps feet in ‘good shape’. More FUNCTIONAL. COSMETICALLY acceptable.

D.A.F.O construction Foot plate shaped to provide increased pressure on Medial Arch Peroneal Notch M/T pad area Extension of the toes

Most orthoses impose a posture, therefore this imposition needs to be realistic. (rule of thumb, is you can only achieve with an orthosis, what you can achieve with your hands.) Collaboration Compromise Communication = COMPLIANCE!

Management “The role of the therapist is to protect patients with cerebral palsy from orthopaedic surgeons” J Gage, Minneapolis

Thank you