Age and Sex-related Analysis of Pediatric Spinal Motion and Comparisons with AIS
Thursday, May 31, 2018
2:00 PM-4:00 PM
BIOMED Master's Thesis Defense
Age and Sex-related Analysis of Pediatric Spinal Motion and Comparisons with Adolescent Idiopathic Scoliosis (AIS)
Jeffrey Hoffman, MS Candidate, School of Biomedical Engineering, Science and Health Systems, Drexel University
Sriram Balasubramanian, PhD, Associate Professor, School of Biomedical Engineering, Science and Health Systems, Drexel University
Adolescent Idiopathic Scoliosis (AIS) is a three – dimensional deformity which is characterized by abnormal curvature and rotation of the spine. Dynamic measurements of normative spinal range of motion (ROM) are commonly used to assess the changes in functionality of the spine due to scoliotic deformity. However, due to the inherent changes in anatomical structures due to growth in children, normative ROM values are also likely to change based on age and sex. Therefore, the objectives of this study are to characterize the age and sex-related changes in the spinal ROM in normative children, quantify muscle activation corresponding to those ROM, and to determine the functional differences in spinal motion between normative and pre-operative AIS pediatric subjects.
A total of 30 normative male and female pediatric subjects between the ages of 6-21 years were recruited to participate in this institutional review board approved study. Subjects performed six active motions to their maximum ROM: forward flexion, extension, lateral bending (left and right), and axial rotation (left and right). Dependent kinematic variables included the angles between adjacent spinal segments and total spinal ROM. Additionally, peak muscle activation during each ROM was measured through surface electromyography electrodes placed bilaterally on the erector spinae, latissimus dorsi, internal and external oblique muscles.
Spinal ROM normalized to subjects’ standing height varied significantly with age for flexion and axial rotation movements. No significant patterns of muscle activation were present; however, trunk muscles activated according to the directionality of the movement suggesting that a combination of forces are responsible for controlling motion. AIS patients had significantly reduced ROM in the spinal region containing the apex of the deformity as compared to age and sex-matched normative subjects; suggesting that the scoliotic deformity restricts motion in the location of the primary curvature.
In addition to providing clinicians with a normative database of trunk kinematics and muscle activation data, these normative kinematic data can also be used to validate subject-specific computational models of the normative pediatric spine.