Low back muscle activity and pelvic rotation during walking

Area of Science:

• Biomechanics
• Human Movement Science
• Musculoskeletal Research

Background:

• Understanding the role of intrinsic lumbar back muscles (ILBM) in gait is crucial for diagnosing and treating back pain.
• Previous research has focused on superficial back muscles, leaving the specific contributions of ILBM during walking less understood.

Purpose of the Study:

• To investigate the activity patterns of the three columns of intrinsic lumbar back muscles (ILBM) during the gait cycle.
• To explore potential relationships between pelvic rotations and ILBM activity during treadmill walking.

Main Methods:

• Simultaneous recording of gait variables, pelvic rotations (frontal and sagittal planes), and rectified and averaged EMG (RA-EMG) from ILBM.
• Data collected from 11 subjects over 48 consecutive strides on a treadmill.

Main Results:

• Bilateral ILBM activity was observed throughout the double support phase of gait.
• Ipsilateral ILBM exhibited greater activity compared to contralateral muscles following heel strike, especially in the longissimus thoracis and iliocostalis lumborum (intermediate and lateral columns).
• No clear correlations were found between pelvic rotations and ILBM activity, suggesting torso position changes are more influential.

Conclusions:

• Intrinsic lumbar back muscles play a significant role in stabilizing the spine during the double support phase of walking.
• Asymmetrical activation patterns in ILBM columns may relate to biomechanical leverage differences during gait.
• Further research is needed to elucidate the complex interplay between pelvic motion, torso dynamics, and ILBM activation during locomotion.