Trunk Muscle Thickness During Supine and Crawling Exercises

Area of Science:

• Biomechanics and Exercise Physiology
• Musculoskeletal Ultrasound Imaging

Background:

• Trunk muscle activation is crucial for spinal stability and injury prevention.
• Understanding exercise-induced muscle thickness changes aids in exercise selection for rehabilitation and training.

Purpose of the Study:

• To measure and compare trunk muscle thickness during Heel Off (HO-ex) and Bird Dog exercises (BD-ex).
• To validate ultrasound measurements for assessing trunk muscle activation during specific hip extension exercises.

Main Methods:

• Ultrasound imaging was used to measure the thickness of lumbar multifidus (LM), erector spinae (ES), external oblique (EO), internal oblique (IO), and transverse abdominis (TrA) in 31 healthy males.
• Muscle thickness was assessed in four conditions: supine rest, HO-ex, crawling, and BD-ex.
• Statistical analysis (ANOVA, Friedman tests) identified significant differences in muscle thickness across conditions.

Main Results:

• Lumbar multifidus (LM) and internal oblique (IO) muscles showed significantly greater thickness during HO-ex compared to supine rest.
• Transverse abdominis (TrA) activation was significantly higher during HO-ex, crawling, and BD-ex than during supine rest.
• Erector spinae (ES) activation was highest during HO-ex and BD-ex compared to supine rest and crawling.

Conclusions:

• The Heel Off exercise (HO-ex) appears more effective for stimulating the multifidus and internal oblique muscles than the Bird Dog exercise (BD-ex).
• Both HO-ex and BD-ex provide comparable activation of the transverse abdominis (TrA) muscle.
• Ultrasound is a viable tool for quantifying trunk muscle responses to different exercise modalities.