Three-Dimensional Spinal and Pelvic Alignment as Determinants of Anticipatory Core Muscle Activation

Area of Science:

• Biomechanical analysis of postural control
• Neuromuscular adaptations in trunk stabilization

Background:

• Three-dimensional (3D) spinal and pelvic alignment is crucial for anticipatory postural control.
• The precise influence of multiplanar alignment deviations on feedforward trunk muscle activation is not fully understood.

Purpose of the Study:

• To investigate whether sagittal, coronal, and transverse spinal and pelvic alignment deviations predict anticipatory muscle activation patterns.
• To identify specific postural deviations that alter feedforward neuromuscular strategies.

Main Methods:

• Surface electromyography (EMG) recorded from external oblique (EO), lumbar multifidus (LM), and transversus abdominis/internal oblique (TrA/IO) muscles.
• Rasterstereography used to quantify multiplanar spinal and pelvic alignment parameters in 100 asymptomatic young adults.
• Regression models analyzed the prediction of EMG onset latency and activation amplitude by alignment parameters.

Main Results:

• Increased vertebral rotation and sagittal imbalance correlated with delayed EO and LM activation.
• Pelvic torsion and tilt asymmetries were associated with less efficient TrA/IO recruitment.
• Balanced spinal curvatures corresponded with earlier, coordinated trunk muscle activation.

Conclusions:

• Multiplanar spinal and pelvic alignment significantly influences anticipatory neuromuscular control strategies.
• Specific postural deviations disrupt feedforward activation patterns, impacting trunk stability.
• Findings provide a functional basis for targeted rehabilitation to restore alignment and prevent dysfunction.