How to differentiate between True equines and Apparent equines

How to differentiate between true equines and Apparent equines

What is equines deformity?

Equinus deformity is a common deformity in children with cerebral palsy. It is characterised by excessive planter flexion of  calcaneus relative to tibia.

It is caused by spasticity or contracture in gastrocnemues or soleus or both resulting in dynamic or static equines

The imbalance disrupts normal ankle movements walking and produces forefoot initial contact instead of heel contact which may persist through the stance phase

This gives rise to toe to toe gait pattern

What is apparent equinus  . 

Hamstring spasticity or contracture can also result in initial forefoot contact with normal range of movements at the ankle. Excessive knee flexion here  gives appearance of equines and to to toe gait with a planigrade ankle when equines does not actually exist.

So we have these two distinct gait patterns that can cause toe to toe walking and initial toe contact but have different mechanism and totally different treatment approaches Rodda and Graham recognised these two patterns as true and appartent equinus

How does apparent equines develops

An apparent equines may result from one of the two ways

1. A jump gait with excessive knee flexion due to spastic hamstrings
2. Most of the children with true equines as they grow loose their initial equines due to weaking planter flexion, over stretching of calf tendons, foot deformities. The resultant progressively ineffective PF KE coupling results in overactive hamstring and excessive knee flexion

What is hiden equinus

In some children with true equines planter flexion knee extension coupling at initial toe contact results in knee recurvatum and stretch on posterior knee capsule with increased hamstring length. With excessive recurvatum the child may have initial heel contact in spite of equines deformity. Thus equines deformity may be masked in presence of knee recurvatum

 How do we differentiate between the true and apparent equines

In true equines ankle is in excessive planterflexion with hips and knee either extended or have little deviation from the normal.

This typically happens in young children with spastic diplegia soon after they begin to walk. Some children however develop fixed ankle contracture and persistant equines

In apparent equines the ankle is plantigrade but these is excessive knee and hip flexion, This is seen in older children with cerebral palsy.