Reduced lower leg muscle activity while balancing on cobblestone shaped surfaces

Area of Science:

• Biomechanics
• Human Movement Science

Background:

• Balance training is crucial for injury prevention and performance enhancement.
• Surface characteristics, including shape and material, are known to influence postural control.

Purpose of the Study:

• To investigate the impact of different balance surface shapes and textures on lower leg muscle activity and ankle joint motion.
• To test the hypothesis that cobblestone-shaped surfaces elicit greater muscle intensity and ankle motion than smooth surfaces.

Main Methods:

• Nineteen healthy participants performed unilateral balancing tasks on hard smooth, soft smooth, and two cobblestone-shaped surfaces.
• Electromyographic (EMG) activity of key lower leg muscles (soleus, gastrocnemii, peroneus longus, tibialis anterior) was recorded.
• Ankle joint kinematics (dorsiflexion/plantarflexion, eversion/inversion) were measured.

Main Results:

• No significant differences in mean ankle kinematics were observed across conditions.
• EMG intensity was significantly lower on cobblestone surfaces (-40% to -80%) compared to the control smooth surface (P<.01).
• EMG intensity was significantly higher on the soft smooth surface (+12% to +30%) compared to the control surface (P<.01).

Conclusions:

• Surface shape, not just material properties, significantly affects lower leg muscle activation during balancing.
• Cobblestone surfaces may require different balance strategies or involve tendon stretching, leading to reduced muscle intensity.
• Consideration of both surface shape and material is essential for optimizing balance training regimens.