CORE STABILITY MUSCLE ACTIVITY DURING STANDING LOWER BODY TWISTING EXERCISES

Area of Science:

• Biomechanics
• Exercise Physiology
• Musculoskeletal Research

Background:

• Limited understanding of abdominal internal oblique (IO) and lumbar multifidus (LM) muscle activity during standing kinetic chain exercises.
• Need to explore muscle engagement in functional, weight-bearing movements.

Purpose of the Study:

• To quantify IO and LM muscle activity during weight-bearing exercises.
• To test the hypothesis that muscle activity varies with lower body positioning during kinetic chain exercises.

Main Methods:

• Electromyographic (EMG) analysis of EO, IO, and LM muscles in 19 healthy adults.
• Measurements taken during lower body twisting exercises in straight leg (SL), athletic position (AP), and dynamic knee extension (DE) stances.
• Exercise performed at two speeds (150 and 90 beats per min), with results reported as % maximum voluntary contraction.

Main Results:

• Internal oblique (IO) muscle activity was significantly higher in the straight leg (SL) position compared to the athletic position (AP).
• Lumbar multifidus (LM) muscle activity was significantly greater in the dynamic knee extension (DE) position than in both SL and AP positions.

Conclusions:

• Lower body extensor muscle contraction may attenuate internal oblique (IO) muscle activity in standing exercises.
• Different lower body positions during kinetic chain exercises elicit distinct patterns of IO and LM muscle activation.