The exact procedure used for measuring PST has previously been investigated for intrarater reliability
in the authors lab with ICC (3,k) reported at 0.96.21
Participants were required to lie on their non-tested (dominant arm) side ½ the length of their humerus from the edge of a standard plinth to allow clearance of the forearm past the plinth during horizontal adduction.
The non-tested extremity was placed under their head to support a neutral head position.
Their trunk was directly perpendicular to the plinth with hips and knees flexed to 45 degrees.
The bubble level anchored to the carpenter’s square was then used to ensure that their trunk was directly perpendicular
to the plinth.
The investigator stood facing the participant at the level of their shoulders and grasped the participant’s elbow with one hand while passively abducting the humerus to ninety degrees while maintaining zero degrees of rotation at the humerus and approximately ninety degrees of elbow flexion.
Humeral positioning was maintained with the initial contact hand while the other hand manually contacted the participant’s lateral scapular border and placed it in a fully adducted (retracted) position.
The retracted scapular position was maintained by the investigator throughout the test.
The position of ninety degrees of humeral coronal abduction with neutral rotation and scapular retraction was the start position of the test (Figures 2A and 2C).
Prior to passively lowering the humerus, a verbal cue was given stating “relax your arm and allow me to lower it to the table”. The investigator then passively lowered the humerus into horizontal adduction toward the plinth in the transverse plane maintaining neutral humeral rotation and scapular stabilization in the retracted position (Figure 2B).
The movement was ceased once the investigator determined that the scapula or humerus was unable to be further stabilized and/or movement stopped. Once the end point was reached, the investigator directed a trained assistant to record the measurement from the inclinometer to a data collection sheet.