The effects of biomechanically optimised ankle-foot orthoses-footwear combinations on the gait of children with cerebral palsy

The purpose of this study was to investigate the effects of the biomechanical optimisation of ankle-foot orthoses and footwear combinations (AFO-FCs) on the gait and energy expenditure of children with cerebral palsy (CP). The child's perception and compliance of wearing AFO-FCs were also investigated. Additional aims were to examine common clinical practice regarding AFO-FC tuning in the UK and to study the validity of using the static shank to vertical angle (SVA) to measure the dynamic SVA during gait.

The study included five children with CP. Outcome measurements included sagittal plane kinematics and kinetics derived using 3D motion analysis, physical examination, heart rate (HR), energy expenditure, speed, distance, energy expenditure index (EEI), static SVA and dynamic SVA and an after study questionnaire.

When studying children with CP, beneficial effects of biomechanically optimised AFO-FCs on gait parameters were evident; the results identified improvements to knee, hip and pelvic kinematics, particularly in cases where the principal gait deviation was hyperextension of the knee in stance.

There were also beneficial effects on energy expenditure with the study highlighting a reduction in energy expenditure, and an increase in self-selected speed and distance covered, when walking in a biomechanically optimised AFO-FC compared to a non-tuned AFO-FC.

The study demonstrated validity in using the static measurement of the SVA to estimate the dynamic SVA during temporal mid-stance (TMST).

The importance of cosmesis and social inclusion was also highlighted as being important for disabled children who are asked to wear adapted footwear and AFOs. However, the results of this study indicated that when there is an improvement in physical function and activities of daily living, children will choose to comply with what they perceive to be uncosmetic orthoses.

It was concluded that biomechanically optimised AFO-FCs have the potential to improve the kinematics and kinetics of gait, energy expenditure, speed and distance covered for children with CP, and that tuning the AFO-FC should be mandatory.