Affiliations: [a] School of Rehabilitation Science, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada | [b] Saskatchewan Health Authority, Children’s Program, Regina, SK, Canada | [c] Toronto Rehabilitation Institute, University Health Network, Toronto, ON, Canada | [d] Department of Physical Therapy, Faculty of Medicine, University of Toronto, Toronto, ON, Canada | [e] College of Kinesiology, University of Saskatchewan, Saskatoon, SK, Canada
Abstract: PURPOSE: For children with cerebral palsy (CP) and equinus, the conventional practice of setting the ankle angle in an ankle-foot orthosis (AA-AFO) at 90∘ may not adequately accommodate gastrocnemius length/stiffness. Therefore, this study compared the effects of statically-optimized solid AFOs with individualized AA-AFOs (iAA-AFOs) and conventionally-prescribed AFOs on gait for children with CP and equinus. METHODS: Ten children with CP and equinus (15 limbs with AFOs), and 15 typically-developing (TD) children participated. For the children with CP, solid AFOs with iAA-AFOs (range = 5∘–25∘ plantarflexion) were compared with their usual AFOs using three-dimensional gait analysis. TD children walked in shoes only. Peak values and Gait Variable Scores (GVS) for joint and segment variables were calculated for stance phase. Responses were categorized using 90% confidence intervals relative to TD data, for each affected leg. RESULTS: Net responses to iAA-AFOs were positive for 60% of limbs and negative for 40%. Knee variables (GVS and peak extension, flexion, and midstance moment) were most positively affected, and foot-floor angle and vertical ground reaction force were most negatively impacted. CONCLUSION: Individualized AFO prescription and iAA-AFOs can impact gait biomechanics for some children with equinus, compared to conventionally-prescribed AFOs. Optimizing dynamic alignment for walking may further improve outcomes.
Keywords: Cerebral palsy, individualized ankle-foot orthosis prescription, AFO ankle angle, equinus, AFO tuning, gait