Trunk muscle activation during stabilization exercises with single and double leg support

Area of Science:

• Biomechanics
• Exercise Physiology
• Rehabilitation Science

Background:

• Trunk stabilization exercises are crucial for core strength and injury prevention.
• Understanding muscle activation patterns during these exercises informs effective training programs.

Purpose of the Study:

• To analyze trunk muscle activity during bridge exercises with varying leg support.
• To compare muscle activation between standard and modified bridge exercises, including the bird-dog exercise.

Main Methods:

• Surface electromyography (EMG) recorded rectus abdominis (RA), external oblique (EO), internal oblique (IO), and erector spinae (ES) activity.
• 29 healthy volunteers performed back, front, and side bridges with double and single leg support, plus a bird-dog exercise.
• Muscle activation was assessed during different exercise variations.

Main Results:

• Back, front, and side bridges primarily activated erector spinae (ES), rectus abdominis (RA), and obliques, respectively.
• Single leg support in bridge exercises significantly increased trunk muscle activation, particularly in the obliques.
• The bird-dog exercise showed high activation in internal obliques (IO) and contralateral erector spinae (ES).

Conclusions:

• Standard bridge exercises with double leg support primarily engage antigravity muscles.
• Elevated leg positions during bridge exercises introduce rotational torques, enhancing trunk rotator activation, especially IO.
• Findings aid clinicians in designing progressive trunk stabilization exercise programs.