Defining trunk kinematics associated with pregnant waddling gait

Area of Science:

• Biomechanics
• Human Movement Science
• Pregnancy Studies

Background:

• Waddling gait, characterized by increased step width and trunk sway, is common during pregnancy.
• Previous research has not fully validated the kinematic components of waddling gait.
• The specific relationship between trunk sway and waddling gait characteristics needs further investigation.

Purpose of the Study:

• To examine the relationships among trunk kinematic characteristics, step width, and balance control during pregnancy.
• To kinematically validate the combination of movements constituting waddling gait.
• To identify specific trunk motion changes associated with the progression of waddling gait throughout gestation.

Main Methods:

• Assessed 23 pregnant individuals every four weeks from 18 to 34 weeks of gestation.
• Utilized quiet standing balance tests and treadmill walking to collect spatiotemporal variables and trunk kinematics.
• Employed multiple linear regressions to analyze correlations between waddling gait characteristics, balance, and step width.

Main Results:

• Step width significantly increased by approximately 1 cm throughout pregnancy (p=0.044).
• Wider step width correlated with reduced sagittal thorax motion relative to global orientation and increased motion relative to the pelvis.
• Increased waddling gait was associated with greater reductions in sagittal trunk motion relative to global orientation (R²=0.255, p=0.014) over gestation.

Conclusions:

• This study provides the first kinematic evidence linking trunk sagittal motion changes to pregnancy-related waddling gait.
• Changes in trunk motion, specifically sagittal plane motion, are specific to the progression of waddling gait during pregnancy.
• Findings can inform the prescription of supportive devices or exercises for balance, back, or pelvic pain in pregnant individuals.