title: High-Pressure Balloon-Assisted Stretching of the Coracohumeral Ligament to Determine the Optimal Stretching Positions: A Cadaveric Study.
abstract: The coracohumeral ligament (CHL) is a thick capsular structure and markedly thickened when affected by adhesive capsulitis. Therapeutic stretching is the most commonly applied treatment for adhesive capsulitis, but optimal stretching postures for maximal therapeutic effects on the CHL have not been fully investigated.
  
  
  
  To investigate the most effective stretching direction for the CHL by measuring the stretching intensity in 5 different directions and to determine whether the stretching intervention resulted in loosening of the ligament by comparing the changes of CHL tightness before and after stretching.
  
  
  
  Biomechanical cadaver study.
  
  
  
  Academic institution cadaver laboratory.
  
  
  
  Nine fresh frozen cadaveric shoulders.
  
  
  
  A high-pressure balloon catheter inserted under the CHL and intraballoon pressure was measured, to evaluate CHL tightness without ligament damage as well as to augment and monitor stretching intensity. To find the optimal stretching direction, the glenohumeral joint was stretched from the neutral position into 5 directions sequentially under pressure-monitoring: flexion, extension [EX], external rotation [ER], EX+ER, and EX+ER+adduction [AD] directions.
  
  
  
  CHL tightness was determined by a surrogate parameter, the additional pressure created by the overlying CHL. The pressure increase (ΔPstr) by a specific directional stretch was considered as the stretching intensity.
  
  
  
  ΔPstrby the 5 directions were mean (standard deviation) values of 0.03 ± 0.07 atm, 0.87 ± 1.31 atm, 1.13 ± 1.36 atm, 1.49 ± 1.32 atm, and 2.10 ± 1.70 atm, respectively, revealing the highest ΔPstrby the EX+ER+AD stretch (P < .05). The balloon pressure by the overlying CHL was decreased from 0.45 ± 0.35 atm to 0.18 ± 0.14 atm (P = .012) before and after the stretching manipulation.
  
  
  
  EX+ER+AD of the glenohumeral joint resulted in the greatest increase in balloon pressure, implying that it could be the most effective stretching direction. A series of stretching manipulations assisted with an underlying pressure balloon were capable of decreasing CHL tightness. With further development and modification, high-pressure balloon-assisted stretching can be a potential therapeutic option to release tight CHL, including the advantage of augmenting and monitoring stretching intensity.
  
  
  
  II.
authors.affiliation: Department of Rehabilitation Medicine, School of Medicine, Kangwon National University, Chuncheon, South Korea.
authors.forename: Sora
authors.initials: S
authors.lastname: Baek
authors.affiliation: Creta Laboratory, Creta Co Ltd, Seoul, Korea.
authors.forename: Kyu Jin
authors.initials: KJ
authors.lastname: Lee
authors.affiliation: Department of Rehabilitation Medicine and Department of Biomedical Engineering, College of Medicine, Seoul National University, Seoul, South Korea.
authors.forename: Keewon
authors.initials: K
authors.lastname: Kim
authors.affiliation: Department of Anatomy, College of Medicine, Chung Ang University, Seoul, South Korea.
authors.forename: Seung-Ho
authors.initials: SH
authors.lastname: Han
authors.affiliation: Catholic Institute for Applied Anatomy, Department of Anatomy, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
authors.forename: U-Young
authors.initials: UY
authors.lastname: Lee
authors.affiliation: Department of Rehabilitation Medicine, School of Medicine, Kangwon National University, Chuncheon, South Korea.
authors.forename: Kun-Jai
authors.initials: KJ
authors.lastname: Lee
authors.affiliation: Department of Rehabilitation Medicine, College of Medicine, Seoul National University, Seoul, South Korea; Rheumatism Research Institute, Medical Research Center, Seoul National University, Seoul, South Korea; Institute of Aging, Seoul National University, Seoul, South Korea; Seoul National University Hospital, Suite 12327, 101 Daehak-Ro Jongno-Gu, Seoul 03080, Korea.
authors.forename: Sun Gun
authors.initials: SG
authors.lastname: Chung
mesh_terms: D001696:Biomechanical Phenomena; D002062:Bursitis; D002102:Cadaver; D006801:Humans; D008023:Ligaments, Articular; D016059:Range of Motion, Articular; D012399:Rotation; D012785:Shoulder Joint