Validity and reliability of 3D marker based scapular motion analysis: A systematic review

Abstract

Methods based on cutaneous markers are the most popular for the recording of three dimensional scapular motion analysis. Numerous methods have been evaluated, each showing different levels of accuracy and reliability. The aim of this review was to report the metrological properties of 3D scapular kinematic measurements using cutaneous markers and to make recommendations based on metrological evidence. A database search was conducted using relevant keywords and inclusion/exclusion criteria in 5 databases. 19 articles were included and assessed using a quality score. Concurrent validity and reliability were analyzed for each method. Six different methods are reported in the literature, each based on different marker locations and post collection computations. The acromion marker cluster (AMC) method coupled with a calibration of the scapula with the arm at rest is the most studied method. Below 90-100° of humeral elevation, this method is accurate to about 5° during arm flexion and 7° during arm abduction compared to palpation (average of the 3 scapular rotation errors). Good to excellent within-session reliability and moderate to excellent between-session reliability have been reported. The AMC method can be improved using different or multiple calibrations. Other methods using different marker locations or more markers on the scapula blade have been described but are less accurate than AMC methods. Based on current metrological evidence we would recommend (1) the use of an AMC located at the junction of the scapular spine and the acromion, (2) the use of a single calibration at rest if the task does not reach 90° of humeral elevation, (3) the use of a second calibration (at 90° or 120° of humeral elevation), or multiple calibrations above 90° of humeral elevation.

Refining scapulothoracic kinematic measurement and characterising scapulothoracic resting posture in those with and without chronic non-specific neck pain

“…Although substantial work has been done in validating the accuracy of non-invasive, skin-based measurement methods of tracking the scapula (Lempereur et al, 2014), errors due to skin movement are still prevalent, especially in shoulder elevation above 90° (Borstad and Ludewig 2002;Ludewig et al, 2004;Prinold et al, 2011;van Andel et al, 2009;Warner et al, 2012). It has been suggested that modifying marker design in combination with adhering to current recommendations regarding attachment location of skin-based marker clusters placed over the scapula could improve the accuracy of this measurement method (Lempereur et al, 2014). Furthermore, the accuracy of such measurements has chiefly been investigated in relation to shoulder and arm movement in mid-positions of the shoulder girdle, with no studies examining their accuracy in more complex movement of the shoulder girdle, such as end range clavicular protraction, retraction, elevation, and depression, which are commonly used during normal daily activities.…”

“…Adequate spacing between markers allows a consistent capture of the markers by the cameras (Lempereur et al, 2014) and accuracy is increased when markers are further apart. This has led to the development of two types of AMC designs: A large base to which markers are directly attached (Warner et al, 2012) and a small base with markers mounted on pins (Lempereur et al, 2012;van Andel et al, 2009) (Figure 2.3).…”

“…Skin-based markers are commonly used to track scapular orientation but are prone to error due to the relative movement between the scapula and the overlying skin (Lempereur et al, 2014).…”

“…Several AMC designs have been used in the past reporting various measurement errors due to skin movement (Lempereur et al, 2012;van Andel et al, 2009;Warner et al, 2012). It is suggested that implementation of the latest recommendation regarding the construction of the AMC design (Lempereur et al, 2014;Warner et al, 2012) and the accumulated knowledge from previously studied AMC designs combined with recommended attachment location will improve the accuracy of the AMC design by reducing skin movement error.…”

“…The acromion marker cluster (AMC) is a skin-based method of tracking scapular motion. This method has proven to be reliable and accurate during humeral elevation below 90° Lempereur et al, 2014;Lempereur et al, 2012;Meskers et al, 2007;van Andel et al, 2009;Warner et al, 2012;Warner et al, 2015) (flexion, abduction, and abduction in the scapular plane) and also in movements such as ergometry (Richardson et al, 2016), humeral external/internal rotation (Chu et al, 2012;Nicholson et al, 2014;van Andel et al, 2009), and movements of daily activities (Nicholson et al, 2014). However, the accuracy of recording scapular motion in activities that include various ranges and combinations of clavicular protraction, retraction, elevation, and depression, independent of humeral movement has not been comprehensively explored (Lawrence et al, 2014;Ludewig et al, 2004;).…”