Infrasternal Angle

A wide infrasternal angle or overly bent thorax may benefit from serratus anterior because it can help relatively straighten the rib cage. A slow sustained exhale allows lateral and deep abdominal muscles to take over. Full treatment resolution requires the ability to shift fluidly between both breathing strategies; the inability to do so is a sign of incomplete resolution. Overhead arm positions are said to improve pump handle and bucket handle mechanics in a wide infrasternal angle presentation. The infrasternal angle should not be treated as a universal ideal that every person must match. A narrow infrasternal angle presentation is associated with a more deeply descended diaphragm than a wide presentation. Many people with total knee replacements present with a wide infrasternal angle, often associated with abdominal girth. The infra-sternal angle is below the sternum at the lower rib cage. An exhaled axial skeleton includes increased sacral nutation, increased lumbar lordosis, a flatter thoracic spine, and a military-style head posture. The clinical target for the IFA is approximately 90 degrees total, or 45 degrees per side symmetrically. Population-level ribcage tendencies s…