How does a systematic tuning protocol for ankle foot orthosis–footwear combinations affect gait in children in cerebral palsy?

Abstract

Purpose

To investigate the effects of a systematic tuning protocol for ankle foot orthosis footwear combinations (AFO-FC) using incrementing heel height on gait in children with cerebral palsy (CP).

Methods

Eighteen children with CP (10.8 ± 3 years, Gross Motor Function Classification System (GMFCS) I–II) underwent 3D gait analysis on a treadmill, while the AFO heel surface was systematically incremented with wedges. Children were subdivided based on their gait pattern, i.e., knee hyperextension (EXT) and excessive knee flexion (FLEX). Outcome measures included sagittal hip and knee angles and moments, shank to vertical angle (SVA), foot to horizontal angle, and gait profile score (GPS).

Results

For both groups, incrementing heel height resulted in increased knee flexion, more inclined SVA, and increased knee extension moments. This resulted in gait improvements for some children of the EXT-group, but not in FLEX. High variation was found between individuals and within-subject effects were not always consistent for kinematic and kinetics.

Conclusions

A systematic AFO-FC tuning protocol using incremented heel height can be effective to improve gait in children with CP walking with EXT. The current results emphasise the importance of including kinematics as well as kinetics of multiple instances throughout the gait cycle for reliable interpretation of the effect of AFO tuning on gait.

Implications for rehabilitation

• A systematic ankle foot orthosis footwear combinations (AFO-FC) tuning protocol using incremented heel height can improve gait in children walking with knee hyperextension.

• Tuning results in changes throughout the gait cycle.

• Little evidence is found for an optimal SVA of 10–12° at midstance.

• For clinical interpretation, both joint kinematic and kinetic parameters should be considered throughout the gait cycle and evaluation should not be based on SVA only.

Keywords:

• Rehabilitation
• biomechanics
• shank to vertical
• paediatrics
• orthotics

Acknowledgements

The authors thank Carlijn Hendriks for her help in implementation of the protocol and setting up the pilot study. Additional thanks to Marjolein Piening and Koen Wishaupt for their help with data collection.

Disclosure statement

The authors report no conflicts of interest.

Additional information

Funding

This work was supported by HandicapNL under Grant #R201605435; Phelps Stichting voor Spastici under Grant #2017.015; JKF Kinderfonds under Grant #20170006; Cornelia-Stichting under Grant #R201605435 and Kinderrevalidatie Fonds Adriaanstichting, as part of the MOVING-CP project.