Effect of Ankle-Foot Orthotic on Postural Sway in Ambulatory Patients with Diplegic Cerebral Palsy

RESNA 28th Annual Conference - Atlanta, Georgia

Xue Cheng Liu1, Fredrick Klingbeil2, Channing Tassone1, and Roger Lyon1

Dept. of Orthopaedics1, Dept. of Physical Medicine & Rehabilitation2, Children’s Hospital of WI, Medical College of WI


Children with spastic diplegia are often seen as equinovarus or equinovalgus. AFOs and SMOs are prescribed for the correction of foot deformity. The goal of our study was to assess the upper trunk rotations with and without orthotics. As a result of our gait analysis, we discovered a reduction of external rotation to normal range and increase speed of the walking. We also found a reduction of excessive plantarflexion. However, postural sway of the upper torso has been significantly increased in sagittal and transverse plane following the use of orthotics. Children with spastic diplegia having poor balance should be carefully assessed for use of orthotics


Spastic diplegia, postural sway, orthotics.


Some patients with cerebral palsy have impaired postural balance and control. Sitting and standing postural control has been studied using center of pressure displacement, electromyography, and kinematic techniques. Distal lower extremity bracing, (SMO/AFOs), is often used for patients with cerebral palsy. The bracing is often prescribed to improve positioning, provide ankle stability, and enhance age-appropriate mobility. Studies have not been done to determine if distal lower extremity bracing is capable of reducing postural sway of ambulatory patients with diplegic cerebral palsy. The purpose of this study was to assess upper torso rotation before and after the use of ankle-foot orthotics.

Although an ankle-foot orthotic does decrease gait abnormalities, it may also alter upper torso sway, resulting in impaired balance and increase energy consumption. The gait of patient with spastic diplegic cerebral palsy, may in fact by more impaired as a result of using distal lower extremity bracing.


Six patients with spastic diplegia cerebral palsy, (3 using bilateral AFOs and 3 using bilateral SMOs), ages 11-18, were studied. All of the patients were able to ambulate. Each patient was asked to walk with and without their orthotics (SMO/AFO) at self-selected speeds while being assessed using an ElectroMagnetic Tracking System (EMTS). The EMTS consists of 16 sensors that operates with 120hz. For this study, 8 sensors were used to record and analyze the patients’ motions. Sensor #1 was placed on the middle of the patient’s PSIS, sensors #2 and #5 which are placed bilaterally on the femur, sensors #3 and #6 placed bilaterally on the patient’s tibia, sensors #4 and #7 placed bilaterally on the forefoot, and sensor #8 was placed on the patient’s third thoracic spinal process.

A total of 24 parameters were analyzed during the study. Each patient’s upper-trunk postural rotation in a 3-D plane, temporal and distance parameters, and velocity and displacement of the third thoracic spinal process were measured. When measuring each patient’s trunk rotation during the gait, maximum and minimum values, and range of motion were obtained. Comparison of patients before and after were analyzed using the Wilcoxon Matched Pairs testing. Both tests used the p-value less than .05 as significant.


There are significant differences in gait parameters between patients with cerebral palsy who walked with and without orthotics (Table 1). Patients displayed significant correction of abnormal ankle rotation and increased speed in gait when using their orthotics. The patients’ gait demonstrated reduced plantarflexion and external rotation of the foot. However, upper-trunk analysis demonstrated significant range of motion in both coronal and transverse planes when using their orthotics.


Table 1: Significant Changes of Posture Sway and ankle joints in diplegic CP Following Foot Orthotics (p< .05)
Parameters No Orthotics Mean + SD OrthoticsMean + SD p-value
Velocity of Gait .39 ± .18 .57 ± .22 0.004
Barefoot vs. Orthotics (plantar flexion-max-stance) -10.39 ± 23.95 6.99 ± 9.68 0.012
Barefoot vs. Orthotics (plantar flexion-max-swing) -14.12 ± 20.67 1.29 ± 6.96 0.012
Barefoot vs. Orthotics (Internal Rot-Max-Stance) -10.07 ± 24.45 1.95 ± 22.02 0.003
Barefoot vs. Orthotics (External Rot-Max-Stance) -24.46 ± 25.7 -14.9 ± 19.2 0.03
Barefoot vs. Orthotics (Internal Rot-Max-Swing) -7.73 ± 25.47 1.37 ± 21.05 0.02
Barefoot vs. Orthotics (External Rot-Max-Swing) -25.36 ± 23.95 -12.71 ± 19.68 0.02
Range of Motion of Upper Torso Obliquity 24.85 ± 19.93 30.09 ± 10.13 0.04
Range of Motion of Upper Torso Rotation 26.82 ± 22.99 42.60 ± 20.90 0.01


Results of the study demonstrated that distal lower extremity bracing normalized external rotation of the ankle joint, toe-toe gait, increased walking velocity. However, the study also demonstrated exaggeration of upper-torso (medial-lateral and transverse) sway during walking. Abnormal standing balance was not affected by the use of an orthotic (1). The implications of this study’s may be significant, given the fact that energy expenditure and posture can influence one’s ability to ambulate and perform age-appropriate activities of daily living.


  1. Rose J, et al. Postural balance in patient with cerebral palsy. Dev Med & Child Neuro 2002, 44:58-63.


We thank Mr. A. Piro for his technical support.

Xue Cheng Liu, PhD MD
(414) 456-4684
8701-W.Watertown Plank Road
MACC Building rm 3018
Wauwatosa, WI 53226