Reliability of a New Test of Levator Scapula Muscle Length

Abstract

The levator scapula (LS) originates at the transverse processes of four upper cervical vertebrae and inserts diagonally into the superior angle of the scapula. The LS elevates and rotates the scapula downward.1-3 As the LS becomes shorter, the superior angle of the scapula rises above normal alignment, giving the entire girdle an elevated appearance.2 Shortened LS contributes to stiffness during flexion and contralateral rotation of the neck.4 Dominance and shortness of the LS are accompanied by weakness and lengthening of its antagonists such as the upper trapezius (UT), lower trapezius (LT), and serratus anterior (SA).2,5-6 Increased stiffness or shortness of the LS can contribute to increased compressive load and shear force on the cervical spine during active neck movement and shoulder abduction, leading to pain or impairment of motor function.7-9 Sahrmann S.2 divided impairments of abnormal scapular alignment into several categories. Among these, downward scapular rotation is the most common impairment in patients with shoulder pain; it is characterized by shortening of the LS and rhomboid and lengthening of the UT and SA. In scapular elevation syndromes, LS shortening acts as a major factor in abnormal movement of the scapula. To raise the arm to 180° with slight depression and posterior tilt, adduction of the scapula should occur in the end range. Reliability of a New Test of Levator Scapula Muscle Length