Dynamic Alignment Changes of the Spine, Pelvis, and Lower Limbs during Gait Analyzed Using Inertial Motion Capture in...

Area of Science:

• Orthopedics
• Biomechanics
• Spine Surgery

Background:

• Adult spinal deformity (ASD) patients often display forward trunk posture during gait, even if they can stand upright statically.
• The specific spinal segments involved in this dynamic forward tilt and their correlation with static alignment are not fully understood.

Purpose of the Study:

• To analyze the walking motion of ASD patients using inertial measurement units (IMUs).
• To clarify the spinal segments contributing to forward trunk tilt during gait.
• To determine the relationship between static sagittal alignment and dynamic gait parameters in ASD.

Main Methods:

• Inertial measurement units (IMUs) were attached to the T1, T12, S1 spinous processes, thigh, and lower leg of preoperative ASD patients.
• Gait data were collected over three 10-second phases (initial, middle, final) and analyzed for dynamic parameters.
• Linear regression evaluated correlations between standing radiographic measurements and dynamic gait parameters.

Main Results:

• Significant increases in the inclination of IMUs at T1, T12, S1, and T12-S1 flexion were observed over time during gait.
• Pelvic tilt (PT) in static standing positively correlated with T12 inclination (r²=0.22), S1 inclination (r²=0.16), and T12-S1 flexion (r²=0.29).

Conclusions:

• Forward trunk posture (anteversion) in ASD during gait results from increased lumbar forward bending and anterior pelvic tilt.
• Lumbar forward bending during gait is significantly correlated with static standing pelvic tilt.
• Patients with high pelvic tilt exhibit poorer dynamic posture during gait than during static standing, necessitating consideration in evaluations.