This project will examine the effect of solid ankle foot orthoses (SAFO) on day to day walking activity and life participation of ambulatory children with cerebral palsy. The investigators propose that SAFO have not effect on levels of walking and life participation versus not wearing the SAFO.

This is a repeated measures trial with randomization of intervention in a cross over design which will quantify daily walking and physical activity levels for children with cerebral palsy (CP) with and without use of a solid ankle foot orthotic (SAFO). Current orthotic management guidelines are based primarily on evidence that SAFO use positively impacts body function and structure in clinic and lab based observations of activity and movement. Prior research has determined that wearing a SAFO improves different aspects of gait and mobility (stride and step length, single limb stance, velocity) for children with CP. However, these studies have been limited by small sample sizes, lack of comparison groups, inconsistency of orthotic fabrication, lack of clear and simple outcome measures and/or randomized control designs. No prior studies have evaluated the effect of SAFO use on activity performance outcomes.

The purpose of this study is to determine the effect of wearing or not wearing current SAFO on a child's walking ability, participation in common life activities, and gait. Children ages 2 - < 10 years who have bilateral cerebral palsy, dynamic equinus gait deformity, and wear bilateral SAFOs fabricated by Cascade DAFO will be approached for participation. Enrolled children are randomly assigned to either wear or not wear their SAFOs for a 14 day intervention period. After this period is over, children will then do the opposite for a second 14 day intervention period. Children attend three study visits; at enrollment, after the first intervention period is over, and after the second intervention period. At the first visit, parents and children (where applicable) complete questionnaires regarding their participation in common life activities in the prior 7 days, and complete a walking evaluation. Children wear a StepWatch accelerometer during each intervention period, which counts the number of steps the child takes and the time each step was taken. After the second intervention period is complete, the child's participation in the research study is complete. One home visit is conducted at the end of each intervention period, where the questionnaires are repeated, and the StepWatch is downloaded and/or re - calibrated per protocol.

Inclusion Criteria:

1. Age 2 to <10 years
2. Gross Motor Function Classification Scale Score of 1 - 3 (ambulatory)
3. Diagnosed with bilateral cerebral palsy
4. Has dynamic equinus gait deformity, defined as PROM to neutral, with equinus weight bearing pattern.
5. Wears bilateral SAFO more than 8 hours per day for more than one month.
6. Has a SAFO prescription of ankle at neutral (zero plantarflexion, with <10 degrees dorsiflexion).
7. The primary goal of the SAFO is to facilitate balance and walking
8. Has SAFOs fabricated by Cascade DAFO, Ferndale, WA.
9. Parent and child are willing to discontinue SAFO use for two weeks.

Exclusion Criteria:

1. Has visual impairment which limits physical activity.
2. Has had lower extremity Botox injections in the past 3 months.
3. Is expected to require changes to medications treating the movement disorder during the study period.
4. Has an uncontrolled seizure disorder which impacts mobility skills.
5. Has had neurosurgical or orthopedic surgeries in the past 6 months.
6. Has had other surgeries or procedures in the past two weeks.

ages 3.0 to 5.8 years, mean age 4.3 years, spastic diplegia cerebral palsy, all wearing current AFO bilaterally to enhance walking activity