Reliability and validity of active and passive pectoralis minor muscle length measures

Abstract

HighlightsThis manuscript presents the measurement properties of a novel technique for lengthening the pectoralis minor muscle.Active and passive lengthening procedures resulted in greater changes in pectoralis minor muscle length when compared to previously reported pectoralis minor muscle stretches.This investigation provides the first evidence to support measurement of the extensibility of the pectoralis minor muscle.

Pectoralis minor length measurements in three different scapula positions

“…The effect of a shortened PM on scapular kinematics and upper limb function is well documented (Borstad & Ludewig 2005 ; Finley et al 2017 ; Gutierrez-Espinoza et al 2019 ; Kibler et al 2013 ; Lee et al 2018 ; Lewis & Valentine 2007 ). Is PM the only perpetrator responsible for the altered scapular position (Morais & Cruz 2016 )?…”

“…The PMI values in the active posterior tilt position of the scapula of our study cannot be compared to other studies as no other study has compared the dominant and non-dominant sides in this position. Two studies that performed measurements with an active posterior tilt position of the scapula did not compare the dominant and non-dominant sides (Finley et al 2017 ; Rosa et al 2017 ). Similarly, the PMI values obtained in the passive posterior tilt position of the scapula in our study cannot be compared to other studies, as the only other study that performed measurements in the passive posterior tilt position again did not compare dominant and non-dominant sides (Finley 2017 ).…”

“…There are discrepancies in the literature regarding the measurement of the PM muscle length, which include participant positioning and the position of the scapula when PM length is measured (Borstad & Ludewig 2005 ; Ko et al 2016 ; Morais & Cruz 2016 ; Struyf et al 2012 ). In these studies, participants were positioned either in standing or in supine (Borstad 2006 , 2008 ; Borstad & Ludewig 2005 ; Cools et al 2010 ; Finley et al 2017 ; Ko et al 2016 ; Lee et al 2015 ; Mackenzie et al 2015 ; Rosa et al 2016 , 2017 ; Struyf et al 2012 , 2014 ). In studies where PM length was measured in standing, the scapula could be in an anteriorly tilted position because of the influence of gravity on posture, thus demonstrating poor diagnostic accuracy and may provide inaccurate values for PM muscle length (Borstad 2006 , 2008 ; Borstad & Ludewig 2005 ; Finley et al 2017 ; Ko et al 2016 ; Lee et al 2015 ; Rosa et al 2016 , 2017 ).…”

“…Rosa and colleagues ( 2017 ) argue that in the resting position of the scapula, the PM muscle is not in an optimal lengthened position and therefore added a measurement where the scapula is taken actively into a posteriorly tilted position. Finley and colleagues ( 2017 ) added a third position, where the scapula is taken passively into a full posteriorly tilted position. Significant differences were found in PM length when the three positions were compared (Finley et al 2017 ).…”

“…Finley and colleagues ( 2017 ) added a third position, where the scapula is taken passively into a full posteriorly tilted position. Significant differences were found in PM length when the three positions were compared (Finley et al 2017 ). The participants were positioned in standing with the elbows extended in the three measurement positions.…”