Page 23 - Maximizing the efficacy of ankle foot orthoses in children with cerebral palsy

In Chapter III, an instrumented treadmill was used to investigate the Shank-to-Vertical Angle as a parameter to evaluate the tuning process within AFO prescription. This study was performed in healthy adults and describes the effects of adjusting heel height and footplate stiffness of an AFO-footwear combination (i.e. AFO and shoes) on the Shank- to-Vertical Angle and lower limb joint angles and moments.
In Chapter IV, the BRUCE instrument was used to measure the mechanical properties of an adjustable spring-hinged AFO to assess its potential use in children with spastic CP. The spring-hinged AFO was set into different stiffness configurations, of which the mechanical characteristics were measured and discussed in relation to AFO function in children with CP walking with excessive knee flexion.
The effects of a rigid AFO and two spring-like AFO configurations of the spring-hinged AFO on gait were investigated in Chapter V. The effects of the AFOs were compared to walking with shoes-only. In addition to relevant biomechanical parameters and walking energy cost, also AFO contributions to ankle work were calculated.
In Chapter VI, the results of the stiffness variations on gait were used to select the optimal AFO stiffness for each patient. This selection was based on the maximal knee extension in stance and walking energy cost while walking with the different AFOs. Children wore their optimal AFO for three months, after which effect of the stiffness- based optimization on daily life activity was assessed.
Chapter VII investigates the effects of an acclimatization period to wearing a newly prescribed AFO on gait biomechanics in children with CP. Although an acclimatization time for the gait pattern to adapt to the new AFO is generally applied, the actual need for such acclimatization to reliably assess the effects of an AFO on gait biomechanics is not known. This chapter evaluates the effects of an AFO directly after tuning, and four weeks later in a subset of relevant biomechanical gait parameters.
In Chapter VIII the overall aim of this thesis is discussed and directions for future research are given.
I
General introduction
23