The effect of dynamic neuromuscular stabilization on trapezius muscle activation during shoulder exercises in individuals with rounded shoulder posture: a pilot study

Abstract

Aims: The aim of this pilot study is to investigate the impact of dynamic neuromuscular stabilization (DNS) technique on the activation of the upper, middle, and lower parts of the trapezius muscle during commonly used shoulder exercises in individuals with rounded shoulder posture. Methods: The study was conducted with 15 individuals exhibiting rounded shoulder posture. The determination of rounded shoulder posture was based on measuring the distance in centimeters between the posterior corner of the lateral acromion prominence and the bed in a supine position. If this distance was 2.5 cm or more, it was considered as rounded shoulder posture. Participants were taught three different shoulder exercises and the DNS respiratory technique, a component of Dynamic Neuromuscular Stabilization. The exercises were randomly performed with and without DNS, and the activation of the upper (UT), middle (MT), and lower (LT) parts of the trapezius muscle was measured separately using an 8-channel surface electromyography (EMG) system (Noraxon Ultium, Scottsdale, USA). Results: The activation of all parts of the trapezius muscle was found to be higher when exercises were performed with DNS compared to without DNS (p<0.05). Additionally, the UT/MT and UT/LT activation ratios were compared during the exercises with and without DNS. It was observed that only during the 1st exercise, the UT/LT activation ratio was higher when exercises were performed with DNS (p<0.05), while in all other cases, it was similar (p>0.05). Conclusion: The primary findings of the study suggest that the activation of all parts of the trapezius muscle is higher when exercises are performed with DNS. This implies that DNS may contribute to more effective exercise performance in terms of the activation of the relevant muscle group, indicating potential positive effects of DNS in rehabilitation programs. However, the participant profile in our study is limited to individuals with rounded shoulder posture. Further research in different populations is needed to generalize the obtained results.