Show simple item record

dc.contributor.authorKay, Anthony D.
dc.contributor.authorRichmond, Dominic
dc.contributor.authorTalbot, Chris
dc.contributor.authorMina, Minas A.
dc.contributor.authorBaross, Anthony W.
dc.contributor.authorBlazevich, Anthony J.
dc.date.accessioned2017-11-24T14:17:29Z
dc.date.available2017-11-24T14:17:29Z
dc.date.issued2016-07
dc.identifier.citationKay, A. D. et al (2016) 'Stretching of Active Muscle Elicits Chronic Changes in Multiple Strain Risk Factors', Medicine & Science in Sports & Exercise, 48 (7):1388.en
dc.identifier.issn01959131
dc.identifier.doi10.1249/MSS.0000000000000887
dc.identifier.urihttp://hdl.handle.net/10545/621967
dc.description.abstractINTRODUCTION: The muscle stretch intensity imposed during "flexibility" training influences the magnitude of joint range of motion (ROM) adaptation. Thus, stretching while the muscle is voluntarily activated was hypothesized to provide a greater stimulus than passive stretching. The effect of a 6-wk program of stretch imposed on an isometrically contracting muscle (i.e., qualitatively similar to isokinetic eccentric training) on muscle-tendon mechanics was therefore studied in 13 healthy human volunteers. METHODS: Before and after the training program, dorsiflexion ROM, passive joint moment, and maximal isometric plantarflexor moment were recorded on an isokinetic dynamometer. Simultaneous real-time motion analysis and ultrasound imaging recorded gastrocnemius medialis muscle and Achilles tendon elongation. Training was performed twice weekly and consisted of five sets of 12 maximal isokinetic eccentric contractions at 10°·s. RESULTS: Significant increases (P < 0.01) in ROM (92.7% [14.7°]), peak passive moment (i.e., stretch tolerance; 136.2%), area under the passive moment curve (i.e., energy storage; 302.6%), and maximal isometric plantarflexor moment (51.3%) were observed after training. Although no change in the slope of the passive moment curve (muscle-tendon stiffness) was detected (-1.5%, P > 0.05), a significant increase in tendon stiffness (31.2%, P < 0.01) and a decrease in passive muscle stiffness (-14.6%, P < 0.05) were observed. CONCLUSION: The substantial positive adaptation in multiple functional and physiological variables that are cited within the primary etiology of muscle strain injury, including strength, ROM, muscle stiffness, and maximal energy storage, indicate that the stretching of active muscle might influence injury risk in addition to muscle function. The lack of change in muscle-tendon stiffness simultaneous with significant increases in tendon stiffness and decreases in passive muscle stiffness indicates that tissue-specific effects were elicited.
dc.description.sponsorshipn/aen
dc.language.isoenen
dc.publisherAmerican College of Sports Medicineen
dc.relation.urlhttp://content.wkhealth.com/linkback/openurl?sid=WKPTLP:landingpage&an=00005768-201607000-00021en
dc.rightsArchived with thanks to Medicine & Science in Sports & Exerciseen
dc.subjectIsokineticen
dc.subjectEccentric trainingen
dc.subjectRange of motion (ROM)en
dc.subjectMuscle stiffnessen
dc.subjectInjuryen
dc.subjectUltrasounden
dc.subjectSport scienceen
dc.titleStretching of active muscle elicits chronic changes in multiple strain risk factors.en
dc.typeArticleen
dc.contributor.departmentUniversity of Northamptonen
dc.contributor.departmentUniversity of Derbyen
dc.contributor.departmentEdith Cowan Universityen
dc.identifier.journalMedicine & Science in Sports & Exerciseen
dcterms.dateAccepted2016-01
refterms.dateFOA2019-02-28T16:17:03Z
html.description.abstractINTRODUCTION: The muscle stretch intensity imposed during "flexibility" training influences the magnitude of joint range of motion (ROM) adaptation. Thus, stretching while the muscle is voluntarily activated was hypothesized to provide a greater stimulus than passive stretching. The effect of a 6-wk program of stretch imposed on an isometrically contracting muscle (i.e., qualitatively similar to isokinetic eccentric training) on muscle-tendon mechanics was therefore studied in 13 healthy human volunteers. METHODS: Before and after the training program, dorsiflexion ROM, passive joint moment, and maximal isometric plantarflexor moment were recorded on an isokinetic dynamometer. Simultaneous real-time motion analysis and ultrasound imaging recorded gastrocnemius medialis muscle and Achilles tendon elongation. Training was performed twice weekly and consisted of five sets of 12 maximal isokinetic eccentric contractions at 10°·s. RESULTS: Significant increases (P < 0.01) in ROM (92.7% [14.7°]), peak passive moment (i.e., stretch tolerance; 136.2%), area under the passive moment curve (i.e., energy storage; 302.6%), and maximal isometric plantarflexor moment (51.3%) were observed after training. Although no change in the slope of the passive moment curve (muscle-tendon stiffness) was detected (-1.5%, P > 0.05), a significant increase in tendon stiffness (31.2%, P < 0.01) and a decrease in passive muscle stiffness (-14.6%, P < 0.05) were observed. CONCLUSION: The substantial positive adaptation in multiple functional and physiological variables that are cited within the primary etiology of muscle strain injury, including strength, ROM, muscle stiffness, and maximal energy storage, indicate that the stretching of active muscle might influence injury risk in addition to muscle function. The lack of change in muscle-tendon stiffness simultaneous with significant increases in tendon stiffness and decreases in passive muscle stiffness indicates that tissue-specific effects were elicited.


Files in this item

Thumbnail
Name:
Kay_et_al_2016_Stretching_of_a ...
Size:
471.8Kb
Format:
PDF
Description:
Author Accepted Manuscript

This item appears in the following Collection(s)

Show simple item record