Document Detail

The Acute Transverse Strain Response of the Patellar Tendon to Quadriceps Exercise.
MedLine Citation:
PMID:  23135371     Owner:  NLM     Status:  Publisher    
INTRODUCTION: The human patellar tendon is highly adaptive to changes in habitual loading but little is known about its acute mechanical response to exercise. This research evaluated the immediate transverse strain response of the patellar tendon to a bout of resistive quadriceps exercise. METHODS: Twelve healthy adult males (mean age 34.0±12.1 years, height 1.75±0.09 m and weight 76.7±12.3 kg) free of knee pain participated in the research. A 10-5 MHz linear-array transducer was used to acquire standardised sagittal sonograms of the right patellar tendon immediately prior to and following 90 repetitions of a double-leg parallel-squat exercise performed against a resistance of 175% bodyweight. Tendon thickness was determined 20-mm distal to the pole of the patellar and transverse Hencky strain was calculated as the natural log of the ratio of post- to pre-exercise tendon thickness and expressed as a percentage. Measures of tendon echotexture (echogenicity and entropy) were also calculated from subsequent gray-scale profiles. RESULTS: Quadriceps exercise resulted in an immediate decrease in patellar tendon thickness (P<.05), equating to a transverse strain of -22.5±3.4%, and was accompanied by increased tendon echogenicity (P<.05) and decreased entropy (P<.05). The transverse strain response of the patellar tendon was significantly correlated with both tendon echogenicity (r = -0.58, P<.05) and entropy following exercise (r=0.73, P<.05), while older age was associated with greater entropy of the patellar tendon prior to exercise (r=0.79, P<.05) and a reduced transverse strain response (r=0.61, P<.05) following exercise. CONCLUSIONS: This study is the first to show that quadriceps exercise invokes structural alignment and fluid movement within the matrix that are manifest by changes in echotexture and transverse strain in the patellar tendon.
Scott C Wearing; Sue L Hooper; Craig Purdam; Jill Cook; Nicole Grigg; Simon Locke; James E Smeathers
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2012-11-6
Journal Detail:
Title:  Medicine and science in sports and exercise     Volume:  -     ISSN:  1530-0315     ISO Abbreviation:  Med Sci Sports Exerc     Publication Date:  2012 Nov 
Date Detail:
Created Date:  2012-11-8     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8005433     Medline TA:  Med Sci Sports Exerc     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
1Faculty of Health Sciences and Medicine, Bond University, Queensland, Australia 2Centre of Excellence for Applied Sport Science Research, Queensland Academy of Sport, Queensland, Australia 3Department of Physical Therapies, Australian Institute of Sport, ACT, Australia 4Faculty of Medicine, Nursing and Health Sciences, Monash University, Victoria, Australia. 5Institute of Health and Biomedical Innovation, Queensland University of Technology, Queensland, Australia.
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