Investigating the effects of head posture muscles’ viscoelastic parameters on pulmonary and functional capacity in healthy individuals

Abstract

Introduction

Forward head posture (FHP) is known to have a large influence on respiratory function by weakening the respiratory muscles. This cross-sectional study is designed to examine the relationship between the tonus, stiffness, and elasticity of head posture muscles and pulmonary capacity.

Methods

Overall, 16 FHP and 17 non-forward head posture (NFHP) individuals were evaluated. The tonus, stiffness, and elasticity of the upper trapezius, semispinalis capitis, pectoral muscles, and sternocleidomastoid muscles were measured with a MyotonPRO® device. Functional capacity was assessed with the 6-minute walk test. Pulmonary function tests employed a spirometer. The Neck Disability Index was applied. FHP was determined by measuring the craniovertebral angle. Physical activity levels were evaluated with the Physical Activity Index.

Results

The study involved 18 (54.54%) female and 15 (45.45%) male students. Their mean age was 21.24 ± 1.82 years. Neck Disability Index scores were higher in participants with FHP than in NFHP individuals (p = 0.037). There were no significant differences in the myotonometric measurements of the analysed muscles between FHP and NFHP groups (p > 0.05). Physiological characteristics of FHP and NFHP participants were different in terms of vital capacity, forced vital capacity, forced expiratory volume in 1 second, and peak forced expiratory volume (p < 0.05).

Conclusions

Owing to the pulmonary capacity differences between FHP and NFHP individuals, it can be concluded that FHP affects pulmonary capacity. Also, pectoral muscles and semispinalis capitis muscles play an important role in thoracic expansion and therefore influence vital capacity.