Effect of posteroinferior capsule tightness on contact pressure and area beneath the coracoacromial arch during pitching motion.

Takayuki Muraki, Nobuyuki Yamamoto, Kristin D Zhao, John W. Sperling, Scott P. Steinmann, Robert H. Cofield, Kai Nan An

Research output: Contribution to journalArticle

32 Citations (Scopus)

Abstract

BACKGROUND: Tightness of the posteroinferior capsule is assumed to be the cause of internal rotation loss in baseball pitchers. Although the relationship between posterior capsule and subacromial impingement has been recognized, this relationship during the baseball-pitching motion is unclear. HYPOTHESIS: Contact pressure during baseball-pitching motion increases with posterior capsule tightness. STUDY DESIGN: Controlled laboratory study. METHODS: Eight fresh-frozen shoulders were used. The peak contact pressure and area on the coracoacromial arch were measured on a custom-designed shoulder experimental device capable of 6 degrees of freedom motion. Simultaneously, the sites of peak pressure on the coracoacromial arch and humerus were observed from various angles. The posteroinferior capsule tightness was simulated by plicating the capsule in the region from 6 to 8 o'clock. The static testing positions correlated to the early cocking, late cocking, acceleration, deceleration, and follow-through phases of the pitching motion. RESULTS: The peak contact pressure during the follow-through phase (0.63 + or - 0.50 MPa) significantly increased with posteroinferior capsule tightness (1.00 + or - 0.65 MPa) (P = .014). Additionally, the contact area on the coracoacromial ligament during the follow-through phase (0.98 + or - 0.67 cm(2)) significantly increased with posteroinferior capsule tightness (1.47 + or - 0.91 cm(2)) (P < .001). The site of the peak contact pressure did not change between the 2 conditions. CONCLUSION: Our findings demonstrate that posteroinferior capsule tightness leads to higher contact pressure under the subacromial arch and increased contact area, particularly on the coracoacromial ligament during the follow-through phase. CLINICAL RELEVANCE: This tightness may affect risk of injury of the rotator cuff and its surrounding tissues by increasing subacromial contact during pitching.

Original languageEnglish (US)
Pages (from-to)600-607
Number of pages8
JournalThe American journal of sports medicine
Volume38
Issue number3
StatePublished - Mar 2010

Fingerprint

Acromioclavicular Joint
Capsules
Pressure
Baseball
Bursitis
Deceleration
Humerus
Equipment and Supplies

ASJC Scopus subject areas

  • Medicine(all)

Cite this

Effect of posteroinferior capsule tightness on contact pressure and area beneath the coracoacromial arch during pitching motion. / Muraki, Takayuki; Yamamoto, Nobuyuki; Zhao, Kristin D; Sperling, John W.; Steinmann, Scott P.; Cofield, Robert H.; An, Kai Nan.

In: The American journal of sports medicine, Vol. 38, No. 3, 03.2010, p. 600-607.

Research output: Contribution to journalArticle

Muraki, Takayuki ; Yamamoto, Nobuyuki ; Zhao, Kristin D ; Sperling, John W. ; Steinmann, Scott P. ; Cofield, Robert H. ; An, Kai Nan. / Effect of posteroinferior capsule tightness on contact pressure and area beneath the coracoacromial arch during pitching motion. In: The American journal of sports medicine. 2010 ; Vol. 38, No. 3. pp. 600-607.
@article{d4a76791d6bd4a65b86abe884da70cbe,
title = "Effect of posteroinferior capsule tightness on contact pressure and area beneath the coracoacromial arch during pitching motion.",
abstract = "BACKGROUND: Tightness of the posteroinferior capsule is assumed to be the cause of internal rotation loss in baseball pitchers. Although the relationship between posterior capsule and subacromial impingement has been recognized, this relationship during the baseball-pitching motion is unclear. HYPOTHESIS: Contact pressure during baseball-pitching motion increases with posterior capsule tightness. STUDY DESIGN: Controlled laboratory study. METHODS: Eight fresh-frozen shoulders were used. The peak contact pressure and area on the coracoacromial arch were measured on a custom-designed shoulder experimental device capable of 6 degrees of freedom motion. Simultaneously, the sites of peak pressure on the coracoacromial arch and humerus were observed from various angles. The posteroinferior capsule tightness was simulated by plicating the capsule in the region from 6 to 8 o'clock. The static testing positions correlated to the early cocking, late cocking, acceleration, deceleration, and follow-through phases of the pitching motion. RESULTS: The peak contact pressure during the follow-through phase (0.63 + or - 0.50 MPa) significantly increased with posteroinferior capsule tightness (1.00 + or - 0.65 MPa) (P = .014). Additionally, the contact area on the coracoacromial ligament during the follow-through phase (0.98 + or - 0.67 cm(2)) significantly increased with posteroinferior capsule tightness (1.47 + or - 0.91 cm(2)) (P < .001). The site of the peak contact pressure did not change between the 2 conditions. CONCLUSION: Our findings demonstrate that posteroinferior capsule tightness leads to higher contact pressure under the subacromial arch and increased contact area, particularly on the coracoacromial ligament during the follow-through phase. CLINICAL RELEVANCE: This tightness may affect risk of injury of the rotator cuff and its surrounding tissues by increasing subacromial contact during pitching.",
author = "Takayuki Muraki and Nobuyuki Yamamoto and Zhao, {Kristin D} and Sperling, {John W.} and Steinmann, {Scott P.} and Cofield, {Robert H.} and An, {Kai Nan}",
year = "2010",
month = "3",
language = "English (US)",
volume = "38",
pages = "600--607",
journal = "American Journal of Sports Medicine",
issn = "0363-5465",
publisher = "SAGE Publications Inc.",
number = "3",

}

TY - JOUR

T1 - Effect of posteroinferior capsule tightness on contact pressure and area beneath the coracoacromial arch during pitching motion.

AU - Muraki, Takayuki

AU - Yamamoto, Nobuyuki

AU - Zhao, Kristin D

AU - Sperling, John W.

AU - Steinmann, Scott P.

AU - Cofield, Robert H.

AU - An, Kai Nan

PY - 2010/3

Y1 - 2010/3

N2 - BACKGROUND: Tightness of the posteroinferior capsule is assumed to be the cause of internal rotation loss in baseball pitchers. Although the relationship between posterior capsule and subacromial impingement has been recognized, this relationship during the baseball-pitching motion is unclear. HYPOTHESIS: Contact pressure during baseball-pitching motion increases with posterior capsule tightness. STUDY DESIGN: Controlled laboratory study. METHODS: Eight fresh-frozen shoulders were used. The peak contact pressure and area on the coracoacromial arch were measured on a custom-designed shoulder experimental device capable of 6 degrees of freedom motion. Simultaneously, the sites of peak pressure on the coracoacromial arch and humerus were observed from various angles. The posteroinferior capsule tightness was simulated by plicating the capsule in the region from 6 to 8 o'clock. The static testing positions correlated to the early cocking, late cocking, acceleration, deceleration, and follow-through phases of the pitching motion. RESULTS: The peak contact pressure during the follow-through phase (0.63 + or - 0.50 MPa) significantly increased with posteroinferior capsule tightness (1.00 + or - 0.65 MPa) (P = .014). Additionally, the contact area on the coracoacromial ligament during the follow-through phase (0.98 + or - 0.67 cm(2)) significantly increased with posteroinferior capsule tightness (1.47 + or - 0.91 cm(2)) (P < .001). The site of the peak contact pressure did not change between the 2 conditions. CONCLUSION: Our findings demonstrate that posteroinferior capsule tightness leads to higher contact pressure under the subacromial arch and increased contact area, particularly on the coracoacromial ligament during the follow-through phase. CLINICAL RELEVANCE: This tightness may affect risk of injury of the rotator cuff and its surrounding tissues by increasing subacromial contact during pitching.

AB - BACKGROUND: Tightness of the posteroinferior capsule is assumed to be the cause of internal rotation loss in baseball pitchers. Although the relationship between posterior capsule and subacromial impingement has been recognized, this relationship during the baseball-pitching motion is unclear. HYPOTHESIS: Contact pressure during baseball-pitching motion increases with posterior capsule tightness. STUDY DESIGN: Controlled laboratory study. METHODS: Eight fresh-frozen shoulders were used. The peak contact pressure and area on the coracoacromial arch were measured on a custom-designed shoulder experimental device capable of 6 degrees of freedom motion. Simultaneously, the sites of peak pressure on the coracoacromial arch and humerus were observed from various angles. The posteroinferior capsule tightness was simulated by plicating the capsule in the region from 6 to 8 o'clock. The static testing positions correlated to the early cocking, late cocking, acceleration, deceleration, and follow-through phases of the pitching motion. RESULTS: The peak contact pressure during the follow-through phase (0.63 + or - 0.50 MPa) significantly increased with posteroinferior capsule tightness (1.00 + or - 0.65 MPa) (P = .014). Additionally, the contact area on the coracoacromial ligament during the follow-through phase (0.98 + or - 0.67 cm(2)) significantly increased with posteroinferior capsule tightness (1.47 + or - 0.91 cm(2)) (P < .001). The site of the peak contact pressure did not change between the 2 conditions. CONCLUSION: Our findings demonstrate that posteroinferior capsule tightness leads to higher contact pressure under the subacromial arch and increased contact area, particularly on the coracoacromial ligament during the follow-through phase. CLINICAL RELEVANCE: This tightness may affect risk of injury of the rotator cuff and its surrounding tissues by increasing subacromial contact during pitching.

UR - http://www.scopus.com/inward/record.url?scp=77953427899&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77953427899&partnerID=8YFLogxK

M3 - Article

C2 - 19966101

AN - SCOPUS:77953427899

VL - 38

SP - 600

EP - 607

JO - American Journal of Sports Medicine

JF - American Journal of Sports Medicine

SN - 0363-5465

IS - 3

ER -