Interactions between posture and locomotion: motor patterns in humans walking with bent posture versus erect posture

Area of Science:

• Biomechanics
• Human Locomotion
• Neuroscience

Background:

• Human erect locomotion is biomechanically unique and efficient.
• The central nervous system (CNS) generates specific motor patterns for erect walking.
• The impact of bent postures on these motor patterns is not fully understood.

Purpose of the Study:

• To investigate if normal motor patterns of erect locomotion are maintained or reorganized in bent postures.
• To analyze kinematic, kinetic, and electromyographic (EMG) data during walking in different postures.

Main Methods:

• Five healthy volunteers walked in regular, knee-flexed, and knee- and trunk-flexed postures.
• Motion, ground reaction forces, and EMG activity were recorded.
• Analysis focused on segment elevation angles, ground reaction forces, and muscle activity waveforms.

Main Results:

• Segmental kinematic waveforms remained largely unchanged across postures.
• Bent postures led to altered temporal coupling, different intersegmental covariation planes, and reduced mechanical efficiency at higher speeds.
• Ground reaction forces showed intermediate characteristics between walking and running; mean EMG activity increased in bent postures.

Conclusions:

• Bent postures preserve segmental kinematics and intersegmental covariation constraints.
• These are maintained via adjustments in kinetics, muscle synergies, and temporal coupling.
• Integrated gait and posture control is supported by shared spatial organization principles.