Does the examiner's experience matter in evaluation of the kinematics of the upper limb?

This study aimed to evaluate test and retest reliability according to examiner experience with the three-dimensional kinematics of the trunk, scapula, and arm segments during flexion and unilateral abduction of the arm. Ten men and 10 women (mean age, 25.1 [1.1] years) participated in this study. Each volunteer participated in six test sessions, four on the first day (two for each examiner) and two on the second day (one for each examiner). A 48-h interval was given between test days. The assessments were made by one examiner with movement analysis experience and a second examiner without experience. For each session (intra-day), the volunteers performed five repetitions of unilateral arm flexions and abductions using their dominant arms. After 1 h, the data were re-collected and all markers were replaced. Data from the trunk, scapula, and arm were analysed at 30°, 60°, 90°, and 120° of arm flexion and abduction using intraclass coefficient correlation, standard error of the measurement, and analysis of variance. The results did not differ between the experienced and inexperienced examiners except for trunk axial rotation at all studied angles and for arm rotation at 120° of abduction. The examiner previously trained in movement analysis marker placement demonstrated the same intra-tester reliability as the inexperienced tester when marker placement accuracy was the variable of interest.