<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:creator>Franchi MV</dc:creator>
  <dc:creator>Fitze DP</dc:creator>
  <dc:creator>Raiteri BJ</dc:creator>
  <dc:creator>Hahn D</dc:creator>
  <dc:creator>Spörri J</dc:creator>
  <dc:date>2020</dc:date>
  <dc:description xmlns:ns0="xml" ns0:lang="en">PURPOSE
This study aimed to compare biceps femoris long head (BFlh) fascicle length (Lf) obtained with different ultrasound-based approaches: 1) single ultrasound images and linear Lf extrapolation, 2) single ultrasound images and one of two different trigonometric equations (termed equations A and B), and 3) extended field of view (EFOV) ultrasound images.


METHODS
Thirty-seven elite alpine skiers (21.7 ± 2.8 yr) without a previous history of hamstring strain injury were tested. Single ultrasound images were collected with a 5-cm linear transducer from BFlh at 50% femur length and were compared with whole muscle scans acquired by EFOV ultrasound.


RESULTS
The intrasession reliability (intraclass correlation coefficient [ICC3,k]) of Lf measurements was very high for both single ultrasound images (i.e., Lf estimated by linear extrapolation; ICC3,k = 0.96-0.99, SEM = 0.18 cm) and EFOV scans (ICC3,k = 0.91-0.98, SEM = 0.19 cm). Although extrapolation methods showed cases of Lf overestimation and underestimation when compared with EFOV scans, mean Lf measured from EFOV scans (8.07 ± 1.36 cm) was significantly shorter than Lf estimated by trigonometric equations A (9.98 ± 2.12 cm, P &lt; 0.01) and B (8.57 ± 1.59 cm, P = 0.03), but not significantly different from Lf estimated with manual linear extrapolation (8.40 ± 1.68 cm, P = 0.13). Bland-Altman analyses revealed mean differences in Lf obtained from EFOV scans and those estimated from equation A, equation B, and manual linear extrapolation of 1.91 ± 2.1, 0.50 ± 1.0, and 0.33 ± 1.0 cm, respectively.


CONCLUSIONS
The typical extrapolation methods used for estimating Lf from single ultrasound images are reliable within the same session, but not accurate for estimating BFlh Lf at rest with a 5-cm field of view. We recommend that EFOV scans are implemented to accurately determine intervention-related Lf changes in BFlh.</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>https://sonar.ch/global/documents/94701</dc:identifier>
  <dc:language>eng</dc:language>
  <dc:relation>info:eu-repo/semantics/altIdentifier/doi/10.1249/MSS.0000000000002123</dc:relation>
  <dc:relation>info:eu-repo/semantics/altIdentifier/pmid/31403609</dc:relation>
  <dc:rights>info:eu-repo/semantics/openAccess</dc:rights>
  <dc:source>Medicine and science in sports and exercise. - 2020</dc:source>
  <dc:subject xmlns:ns1="xml" ns1:lang="en">Female</dc:subject>
  <dc:subject xmlns:ns2="xml" ns2:lang="en">Hamstring Muscles</dc:subject>
  <dc:subject xmlns:ns3="xml" ns3:lang="en">Humans</dc:subject>
  <dc:subject xmlns:ns4="xml" ns4:lang="en">Male</dc:subject>
  <dc:subject xmlns:ns5="xml" ns5:lang="en">Reproducibility of Results</dc:subject>
  <dc:subject xmlns:ns6="xml" ns6:lang="en">Risk Factors</dc:subject>
  <dc:subject xmlns:ns7="xml" ns7:lang="en">Skiing</dc:subject>
  <dc:subject xmlns:ns8="xml" ns8:lang="en">Ultrasonography</dc:subject>
  <dc:subject xmlns:ns9="xml" ns9:lang="en">Young Adult</dc:subject>
  <dc:title xmlns:ns10="xml" ns10:lang="en">Ultrasound-derived Biceps Femoris Long Head Fascicle Length: Extrapolation Pitfalls.</dc:title>
  <dc:type>http://purl.org/coar/resource_type/c_6501</dc:type>
</oai_dc:dc>