Intra-protocol repeatability and inter-protocol agreement for the analysis of scapulo-humeral coordination

Abstract

Multi-center clinical trials incorporating shoulder kinematics are currently uncommon. The absence of repeatability and limits of agreement (LoA) studies between different centers employing different motion analysis protocols has led to a lack dataset compatibility. Therefore, the aim of this work was to determine the repeatability and LoA between two shoulder kinematic protocols. The first one uses a scapula tracker (ST), the International Society of Biomechanics anatomical frames and an optoelectronic measurement system, and the second uses a spine tracker, the INAIL Shoulder and Elbow Outpatient protocol (ISEO) and an inertial and magnetic measurement system. First within-protocol repeatability for each approach was assessed on a group of 23 healthy subjects and compared with the literature. Then, the between-protocol agreement was evaluated. The within-protocol repeatability was similar for the ST ([Formula: see text] = 2.35°, [Formula: see text] = 0.97°, SEM = 2.5°) and ISEO ([Formula: see text] = 2.24°, [Formula: see text] = 0.97°, SEM = 2.3°) protocols and comparable with data from published literature. The between-protocol agreement analysis showed comparable scapula medio-lateral rotation measurements for up to 120° of flexion-extension and up to 100° of scapula plane ab-adduction. Scapula protraction-retraction measurements were in agreement for a smaller range of humeral elevation. The results of this study suggest comparable repeatability for the ST and ISEO protocols and between-protocol agreement for two scapula rotations. Different thresholds for repeatability and LoA may be adapted to suit different clinical hypotheses.

Reliability and precision of 3D wireless measurement of scapular kinematics

“…Anatomical coordinate systems defined in the ISEO protocol are comparable but not similar to the ISB recommendations (International Society of Biomechanics) on definitions of joint coordinate systems described by Wu et al [4] (as used by e.g. Van Andel et al [20]), due to the lack of direct identification of anatomical landmarks with IMMS [34]. For the scapula, the x-axis (pointing lateral along the spina) is comparable to the ISB z-axis (the line connecting Trigonum Scapulae and Angulas Acromialis).…”

“…A protocol has been developed to use these sensors for measurement of shoulder and elbow kinematics (ISEO: INAIL Shoulder & Elbow Outpatient protocol) [32]. The same group performed a study with wired IMMS, showing good intra-and inter-observer agreement [33] and comparable within protocol-repeatability with an optoelectronic measurement system [34]. Nowadays, wireless IMMS are available (MTw, Xsens Technologies, NL) that increases the applicability in clinical setting.…”

Measurement of scapular dyskinesis using wireless inertial and magnetic sensors: Importance of scapula calibration

“…A few studies evaluated the intra-and inter-observer reliability and precision of such a system in healthy subjects (Cutti et al, 2008;Parel et al, 2014Parel et al, , 2012van den Noort et al, 2014). Technical dynamic accuracy of IMMS sensors used in the latter study is reported to be around 2°(Xsens Technologies B. V., 2011).…”

Shoulder biomechanics and the success of translational research

“…This is an almost unexplored topic in motion analysis in general [2,9,14,15], and for the upper extremity specifically. The paper by Parel et al [21] gives a contribution on this regard, by assessing the agreement between two scapula-tracking systems (scapula tracker [18] and spine tracker [10]), based on two different motion analysis technologies, namely opto-eletronic and inertial and magnetic sensors [10,11]. Filling a gap in current literature, the paper points out a clear set of conditions for agreement between systems for scapula tracking, based on state-ofthe-art parameters, i.e., within-protocol repeatability and Bland-Altman Limits of Agreement.…”