Abstract
Aim
The aim of the study was to characterise gait in patients with achondroplasia post lengthening.
Patients/Materials and Methods
Full kinematic and kinetic lower limb gait analysis was performed at the Sheffield Children's Hospital gait laboratory, Sheffield, using a Vicon system (6 cameras working at 50Hz) and processed using Plug In Gait modelling software. The lengthened Achondroplasia group (n=11, mean age = 24.5 ± 6.1) had previously undergone surgical lengthening of the legs. The lengthened Achondroplasia group was compared to a control group of 11 adult normal subjects.
Results
Averaged sagittal plane kinematics are shown in Figure 1. The key sagittal plane characteristics we found were increased anterior pelvic tilt (Achondroplasia mean = 22.2 ± 7.1°, normal mean = 14.2 ± 5.3°), decreased peak hip extension (Achondroplasia = 10.5 ± 11.2°, normal = −5.8 ± 5.3°), increased peak hip flexion (Achondroplasia = 49.3 ± 9.8°, normal = 40.0 ± 5.2°), and reduced knee extension in midstance (Achondroplasia = 14.0 ± 8.5°, normal = 4.4 ± 8.5°) At the ankle the mean of the lengthened Achondroplasia group lies within one standard deviation of the normal dataset throughout the gait cycle.
Summary and Conclusions
Three dimensional gait analysis of people with Achondroplasia following lower limb-lengthening surgery showed characteristic Achondroplasic gait, that is: increased anterior pelvic tilt, reduced hip extension and increased hip flexion. The group of lengthened Achondroplasia participants also failed to extend the knees fully in midstance. At the ankle the sagittal plane kinematics were within one standard deviation of the normal dataset.
