Between-day repeatability and symmetry of multifidus cross-sectional area measured using ultrasound imaging.

Study Design: Prospective test-retest, intrarater reliability study.

Objectives: To estimate the intrarater reliability, asymmetry, and associated error with measurement of the cross-sectional area (CSA) of the bilateral S1 multifidi when measured by a physical therapist following a short course of self-directed training in ultrasound imaging.

Background: There is increasing interest in the assessment of the lumbar multifidus during the recovery from low back injury.

Actions of the scalene muscles for rotation of the cervical spine in macaque and human.

Study Design: Multiple single-subject design in 2 parts: 1 in anesthetized monkeys and a follow-up in human cadavers.

Objectives: To determine whether anterior, middle, and posterior scalene muscles rotate the cervical spine to the same (ipsilateral to the muscle) or opposite (contralateral to the muscle) side.

Background: Some physical therapy and anatomy textbooks indicate that all 3 scalenes rotate the cervical spine to the same side, some indicate that all rotate to the opposite side, and the rest ascribe different functions to the different scalenes.