title: Measurement of pectoralis minor muscle length: validation and clinical application.
abstract: METHODS
  Clinical measurement validity study.
  
  
  OBJECTIVE
  To validate the measurement of the pectoralis minor muscle length using palpable landmarks and to explore the accuracy of the measurement using a clinical instrument.
  
  
  BACKGROUND
  The pectoralis minor is believed to adaptively shorten. Individuals with a relatively short pectoralis minor demonstrate scapular kinematic alterations that have been associated with shoulder impingement.
  
  
  METHODS
  A 3-dimensional electromagnetic motion capture system was used to calculate the length of the pectoralis minor in 11 cadavers, using 2 measurement techniques. In addition, a measurement with the electromagnetic system using palpable landmarks was compared to a measurement with both a caliper and tape measure in vivo.
  
  
  RESULTS
  In cadavers, a measurement using palpable landmarks was determined to be a valid measure of the actual muscle length visualized and measured following dissection. There was a high intraclass correlation coefficient and a small root-mean-square error between these 2 measures. High intraclass correlation coefficients were also calculated in vivo when measurements with the clinical instruments were compared with the electromagnetic device measures.
  
  
  CONCLUSIONS
  A measurement using palpable landmarks for pectoralis minor length validly represents the muscle length in cadavers. A caliper or tape measure may be used clinically with high accuracy and may help clinicians determine the need for and the effectiveness of interventions for lengthening this muscle.
authors.affiliation: Physical Therapy Division, The Ohio State University, Columbus, OH 43210-1234, USA. borstad.1@osu.edu
authors.forename: John D
authors.initials: JD
authors.lastname: Borstad
mesh_terms: D000886:Anthropometry / Q000379:methods*; D002102:Cadaver; D006801:Humans; D010173:Palpation; D010369:Pectoralis Muscles / Q000502:physiology*; D010818:Practice Patterns, Physicians'