First Branch Scalenus Medius

Origin: The posterior tubercles of the axis transverse processes.

Origin: The posterior tubercle of the transverse process of axis vertebra.

Insertion: The superior surface of the first rib, between the tubercle and subclavian groove.

Located: The scalenus medius is anterior in relation to the second branch levator forming an acute angle as they descend from their common origin.  The index finger is placed just below the transverse process of axis, occupying the space between the levator and scalenus medius.  The scalenus medius runs slightly oblique toward its anterior insertion.

Listing Involvement: The scalenus medius is complimentary to the second branch levator in its action. Although the scalenus medius does arise from the posterior tubercle of the axis transverse, it approaches or "leaves" the axis from an oblique anterior insertion and thus corrects rotation, as the transverse moves posterior upon axis pivot misalignment (the scalenus medius works opposite the second branch levator except in axis entire segment listings).  Therefore the scalenus medius corrects rotation of axis opposite the side of spinous deviation.

Working Sensation: Upon palpation the scalenus medius is clearly discerned and definable as a slender muscle band.  When working for correction, the scalenus medius is palpated to a relatively firm degree.