Date of Award


Degree Type


Degree Name

Master of Science in Kinesiology



First Advisor

Ryan Chapman


INTRODUCTION: Worldwide, approximately 800 women die daily from preventable maternal causes of death (COD). These CODs (e.g. prolonged labor, hemorrhage) are frequently connected to biomechanical limitations during childbirth. There is increased risk for complications/death during labor/delivery if pelvis/hip anatomy does not biomechanically change enough. Monitoring pelvic/hip biomechanical changes throughout pregnancy may help detect complications that arise during or prior to labor/delivery.

METHODS: Sixteen females (10 nulligravid female control participants, 6 gravid female participants) were enrolled. All participants performed walking, stair ascent, and stair descent while lower extremity optical motion capture and electromyography data (bilateral hip/knee flexors/extensors) were captured. Controls were assessed once, while gravid participants completed 5 timepoints (1 x T1, 1 x T2, 2 x T3, 1 x postpartum). Outcome variables included 3D peak pelvis/hip joint angles, neuromuscular features (peak EMG magnitude and dominant frequency), and post-partum patient reported outcome measures (PROMs). A Pearson’s Correlation evaluated associations between peak joint angles/EMG magnitude and post-partum PROMs.

RESULTS: There was a significant impact of pregnancy status and gestation cycle timepoint on peak pelvis and hip joint angles in the sagittal plane during walking and stair descent. Kinematics changed significantly throughout pregnancy and returned towards pre-pregnancy values after parturition (p < 0.05). While gestation cycle timepoint was not significantly connected with EMG variables, the dominant frequency of the gluteus maximums was significantly different between the control cohort and pregnant cohort (p = -0.026). Additionally, kinematic values were significantly correlated with postpartum outcomes during walking. Specifically, it was found that hip transverse plane motion (i.e. internal/external rotation) was significantly correlated to Birth Satisfaction Scale scores (r > 0.98, p < 0.02). Additionally, hip extension was significantly correlated with active pushing time during labor (r = 0.97, p = 0.03).

DISCUSSION: Biomechanics are significantly impacted by pregnancy, mostly in the sagittal plane. More critically, these changes are correlated to clinical delivery outcomes, implying there may be a direct link between how the pelvis/hips biomechanically prepare for labor and intra-/post-partum outcomes. This result indicates there is the possibility for developing better screening and treatment modalities to reduce complications during labor and delivery.

EMG_FFT_template.m (5 kB)
FFT Template

EMG_StairsAS_FFT_template.m (3 kB)
StarisAS FFT Template

EMG_StairsDS_FFT_template.m (5 kB)
StairsDS FFT Template



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