Trapezius muscle activity during wall slide exercise: Natural vs corrected head posture.

BACKGROUND

Head posture affects muscle activation. However, the effect of head posture on trapezius muscle activation during wall slide exercise has not been investigated.

SETTING

A cross-sectional study.

PURPOSE: To investigate the effect of head posture (natural head posture (NHP) and corrected head posture (CHP)) on trapezius muscle activation levels and ratios during wall slide exercise.

METHODS

Nineteen healthy participants (12 female and 7 male, Age = 24.84 ± 4.87 years, Body Mass Index = 22.29 ± 3.0 kg/m2) were asked to perform wall slide exercise with both NHP and CHP, separately. Muscle activations of the upper trapezius (UT), middle trapezius (MT), and lower trapezius (LT) were measured with a surface EMG Noraxon MiniDTS system in the ascending, stationary, and descending phases of the exercise.

RESULTS

All trapezius muscles demonstrated low muscle activation (<20 % Maximum Voluntary Isometric Contraction) in both head postures. The UT and MT muscle activations during the wall slide exercise were greater with CHP than with NHP (respectively, p = 0.001, p = 0.010). However, LT muscle activation, UT/MT, and UT/LT muscle activation ratios were similar in both head postures (p > 0.05). The UT muscle activation during the ascending phase was higher than the activation in the descending phase (p < 0.000). Also, MT and LT muscle activations during the ascending phase were higher than the stationary and descending phase (both, p < 0.000).

CONCLUSION

Performing the wall slide exercise with CHP and focusing on the ascending phase may provide a more efficient shoulder rehabilitation program by increasing overall trapezius muscle activation and preserving the balance in trapezius muscles without changing muscle activation ratios.