DESCRIPTION (Adapted from the Applicant's Description): The long term goal is to improve function in children with cerebral palsy (CP). Equinus deformity is the most common problem in children with CP. Surgeries to correct this problem include heel cord advancement (HCA) and heel cord lengthenings described by White (HCL-W) and Vulpius (HCL-V). No investigators have simultaneously assessed outcomes of HCA, HCL-W, and HCL-V surgeries. No investigators have simultaneously assessed outcomes of HCA, HCL-W, and HCL-V surgeries. The investigators are presently comparing the HCA surgery with the HCL-W surgery. Their primary purpose of this study is to add the HCL-V group to compare the outcomes of all 3 surgeries. When the mechanics of the angle are modeled it becomes apparent that the surgeries may not have the same effect on ankle joint function. Thus, it is possible that one surgery may be more beneficial to a specific patient than another. The secondary purpose of this study is to develop an objective selection criterium for determining the most effective heel cord surgery for a child with CP. Specific Aim 1: Compare changes in impairment and function in groups of children with CP undergoing HCA, HCL-2, and HCL- V surgeries and a non-surgical CP control group. Impairment measures will include: (1) maximum ankle joint torques, (2) ankle range of motion, and (3) ankle dorsiflexion and range of motion. Functional measures will include: (1) oxygen uptake during gait, (2) specific gait variables, 93) Gross Motor Function Measure (GMFM) and (4) a disability questionnaire. Children will be tested prior to surgery and at 12 months post-surgery. ANOVA will assess equality of the means for the measures between groups and as a function of surgery. The null hypothesis that: (1) no differences in measures will exist as a result of a surgery and (2) no differences in measures will exist among groups will be tested. Specific Aim 2: Pre and post-surgery functional measures will be used to determine if any of the 4 groups of children with CP have shifted closer to corresponding values for a group of children with able bodies (AB controls). The null hypothesis that no significant differences in improvement will exist between the 4 CP groups relative to the AB controls will be tested. Specific Aim 3: Evaluate the importance of pre-surgery impairment measures as predictors of functional change resulting from the HCA, HCL-2, and HCL- V surgeries. Multiple regression analysis will use the impairment measures to predict the functional variables. Co-variates such as the specific surgery and/or initial level of function will be included to consider patient selection procedures. The hypothesis that pre-surgery impairment measures will predict functional change in the HCA, HCL-W, and HCL-V groups of children will be tested. Upon completion the investigators expect to demonstrate that the 3 surgeries are effective in improving function of children with equinus deformity; however better selection procedures are desirable.