GUEST BLOGGER: Kathryn Biel

This clinical question was received from Holly:

Is there anything that can be done for a severe rocker bottom foot? Child is 8, spastic diplegia, has heel cord contracture, but has had two heel cord lengthenings. Currently not using AFOs, does have a slight crouch gait (was a toe walker before most recent heel cord lengthening). His foot hits the floor flat, but the mid foot then bottoms out and heel lifts during early stance. Is there any way to stretch gastrocs? I’d obviously love to avoid further surgery. 

Rocker bottom foot can occur in a number of situations. It can be a congenital condition in which the navicular is malpositioned at the neck of the talus. This condition is rigid, with the foot in and equinus position with dorsiflexion. It is common in chromosomal abnormalities. Treatment recommendations include early plaster casting in plantar flexion and inversion to stretch ligaments (talonavicular, deltoid, and calcaneal cuboidal) and muscles (triceps surae and peroneous brevis) that are tight. Surgical reconstruction of the foot itself is also used as treatment.

However, rocker bottom foot can occur in cerebral palsy as a secondary impairment that results from spastic plantar flexors. In this condition, during weight bearing, the spastic plantar flexors pull the hindfoot upwards, resulting a weight shift forward to the forefoot. The center of gravity is moved forward as well. Over time, with the weight bearing surface stretches out and then eventually reverses the longitudinal arch, resulting in a rocker bottom appearance. Additionally, the spasticity through the gasctrocs over powers the inverters, which results in a collapse into valgus.

When stretching in PT, it is important to maintain stabilize the subtalar joint (through a firm hold on the calcaneus) so that it does not further collapse into valgus. Stretch should not be applied to the forefoot alone.

Orthotics may be the best bet to  stabilize the subtalar joint while resisting plantarflexion. Orthotics that do not stabilize the subtalar joint will contribute to a further valgus deformity. The orthotics must include sufficient support and sculpting to hold the calcaneus stable. A skilled orthotist and close collaboration is key to make sure the hindfoot is stable in weightbearing.

Also, due to lengthening surgeries, the triceps surae is often weak, resulting in the crouched gait. Strengthening may be something to consider. Also, on going tone management (Botox or Baclofen, for example) is important to monitor as it is the spasticity that caused the deformity in the first place.

Does anyone else have ideas for how to non-surgically treat rocker bottom foot in a child with cerebral palsy? I’d love to hear what works for you. 

~Kathryn Biel, PT, DPT