Positional changes in distance to the pleura and in muscle thickness for dry needling

Abstract

ObjectiveThis study was conducted to measure and to determine differences in tissue depth in the upper back for two prone positions and to stratify the results by body composition and sex of the patient. In addition, muscle thickness changes with positioning were assessed. This information is important for clinicians who dry needle in the thorax area, cognizant of the dangers of inadvertently piercing the pleura or lung tissue. DesignDescriptive cross-sectional. SettingHealth and Human Performance laboratory at a university campus. ParticipantsSample of convenience of 60 college-aged subjects, 20 subjects in three body composition groups. Main outcome measuresDistances from skin to lung tissue, skin to ribs and muscle thickness were measured and compared between two prone positions. ResultsThere was a significant increase in depth to the lung tissue (0.7cm, 95% confidence interval 0.4–1.0cm) when using a bolster under the shoulder. There were also differences in depths between body composition classifications and between sexes, but not between sides. The average thickness of all muscles increased significantly by up to 0.4cm (95% confidence interval 0.3–0.5) when the shoulder was positioned in retraction. ConclusionsPositioning, body constitution and sex of the patient change tissue depth significantly and should be considered when dry needling. This change is largely attributed to a modification in muscle thickness.