Use of a Knee Orthosis to Advance Motor Control in a 3-Year-Old with Achondroplasia: A Case Report

ABSTRACT Introduction Children with achondroplasia experience numerous impairments in body structure and function, including hypotonicity, weakness, joint laxity/hypermobility, skeletal malalignment, and delays in gross motor development. Atypical patterns of movement are often used to compensate for short limbs, weakness, laxity at the joints, and bony malalignment. As a result of these atypical patterns, pain and self-restricted movement frequently begin at a young age. Surgical interventions are the general recommendation to address progressive deformity and resultant pain. Lower-limb bracing to address alignment and motor control in children with other diagnoses that include hypotonia has had positive results, including improved alignment and gross motor skills, but has not been explored in children with achondroplasia. Materials and Methods A 3-year-old child with achondroplasia participated in an intervention using a neoprene knee orthosis with hyperextension resistance at the knee combined with a play-based, proprioceptive-intensive home exercise program. We hypothesized that the knee orthosis would increase proprioceptive input, improve alignment, and have a positive effect on gross motor skill acquisition and refinement. Early training may also have a positive impact on potential future pain and disability. Results Improvements in alignment and motor control were seen in this child after 12 weeks of this intervention but were not initially sustained. After an additional 6 weeks of intervention, significant progress was demonstrated in lower-limb alignment and motor control, as evidenced by independent use of proper movement patterns. Delay in gross motor skill was reduced from 27% to 22%. Discussion Motor skills training in proper alignment with aid of neoprene knee orthosis resulted in positive gains for a 3-year old with achondroplasia. Conclusion This intervention may be helpful for other children with achondroplasia who experience hypotonia, malalignment, and atypical movement patterns. Sufficient amounts of practice and intensity are recommended for permanent motor learning to occur.