Replacing a Swiss ball for an exercise bench causes variable changes in trunk muscle activity during upper limb...

Area of Science:

• Exercise Physiology
• Biomechanics
• Sports Science

Background:

• Swiss balls are increasingly used in exercise programs due to their unstable surface.
• This instability may necessitate greater trunk muscle activation for spinal stability and balance.
• The study investigated if Swiss balls enhance trunk muscle engagement during upper body exercises.

Purpose of the Study:

• To determine if using a Swiss ball increases trunk muscle activation compared to a stable exercise bench.
• To assess the impact of unstable surfaces on spinal stabilizing musculature during strength training.

Main Methods:

• Electromyography (EMG) measured the activity of four trunk muscles.
• Exercises included chest press, shoulder press, lateral raise, biceps curl, and triceps extension.
• Muscle activity was compared between a stable bench and an unstable Swiss ball surface using ANOVA.

Main Results:

• No statistically significant difference in trunk muscle activity was found between the Swiss ball and exercise bench conditions.
• A high degree of inter-subject variability in muscle response was observed.
• Individual responses to surface stability differed significantly.

Conclusions:

• Replacing an exercise bench with a Swiss ball does not consistently enhance trunk muscle activation during upper limb strength exercises.
• The belief that Swiss balls inherently increase spinal stabilizing muscle activity may not be justified.
• Ground-based exercises with biomechanical justification are recommended for spinal stability training.