Exploratory Investigation into Energy Expenditure Using Tuned versus Nontuned Ankle-Foot Orthoses-Footwear Combinations in Children with Cerebral Palsy

Introduction Children with cerebral palsy (CP) commonly expend two to three times as much energy to walk as typically developing children. Research shows that the effects of nontuned ankle-foot orthoses (AFOs) on energy expenditure are inconclusive. Tuning of an ankle-foot orthosis-footwear combination (AFO-FC) has demonstrated an improvement in the kinetics and kinematics of pathological gait, particularly knee flexion during stance phase, which are key determinants of an energy-efficient gait. The objective of this study was to compare the submaximal energy expenditure via indirect calorimetry and speed and distance walked of tuned and nontuned AFO-FCs and barefoot gait in children with CP. 

Methods This study is a performance assessment of four children aged between 7 and 10 years with a diagnosis of CP (one hemiplegic and three diplegic participants, two female and two male, with a Gross Motor Function Classification System [GMFCS] of 2) at a gait analysis laboratory. 

Results There was a reduction in gross submaximal energy expenditure and energy efficiency index (EEI) based on O₂ in three of the four participants tested when wearing tuned compared with a nontuned AFO-FC. The reduction ranged from 9.2% to 33.7%. Speed and distance covered also showed improvement in the tuned condition. 

Conclusions Tuning the AFO-FC of children with CP has the potential to decrease energy expenditure and increase speed and distance compared with providing a nontuned AFO-FC.