- May 2, 2026The external intercostal muscles occupy the posterior and lateral intercostal spaces, with fibres running inferomedially analogous to the external oblique…
- May 2, 2026The internal intercostal muscles run perpendicular to the external intercostals (superoanteriorly rather than inferoanteriorly), depressing the ribs during forced expiration.…
- May 2, 2026The middle trapezius runs almost horizontally from the upper thoracic spinous processes to the scapular spine, providing the primary scapular…
- May 2, 2026The lower trapezius is the most important trapezius component for overhead function, providing the scapular depression and upward rotation forces…
- May 2, 2026The semispinalis thoracis spans five or more vertebral levels from the mid-thoracic transverse processes to the lower cervical and upper…
- May 2, 2026The clavicular head of the pectoralis major is the upper portion of the fan-shaped pectoral muscle, providing the primary force…
- May 2, 2026The sternocostal head is the larger and more powerful component of the pectoralis major, providing the primary force for arm…
- May 2, 2026The thoracic iliocostalis runs rib-to-rib in the thoracic region, extending and stabilising the thoracic spine while also stabilising the rib…
- May 2, 2026The longissimus thoracis is the largest component of the erector spinae and the primary extensor of the thoracic and lumbar…
- May 2, 2026The rotatores are the deepest and shortest muscles of the transversospinalis group, spanning only one or two vertebral levels and…