Force Enhancement of Musculus Quadriceps Femoris During and After Excentric Muscle Activity in Vivo

Study Overview
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Brief Summary
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Force enhancement (FE) describes the phenomenon of strength potentialization of a muscle cell or the complete muscle during and after active extension compared to the strength of an isometric contraction with same muscle length. The underlying physiological mechanism of this phenomenon is not completely known today. In vitro trials indicate that the interaction of an active and a passive component on the cellular level are responsible for the higher strength measurements. So far FE could be shown in vitro and in vivo on muscle fibers and small human muscles. Further research is needed for verification of the existence of FE in voluntary motor activity in everyday life. In order to approach this objective the investigators will scrutinize the functionality of the deliberately activated musculus (m) quadriceps femoris during and after active extension on the basis of in vivo studies.

Detailed Description
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The research proposal is resubmitted with no amendments made regarding content.

Official Title
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Force Enhancement of m. Quadriceps Femoris During and After Excentric Muscle Activity in Vivo by Maximal and Sub-maximal Deliberately Activation.

Conditions
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Muscle Quadriceps Femoris, Healthy

Intervention / Treatment
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* Other: muscle activation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Males without previous muscular or neurophysiological diseases Age between 20 and 40 years Exclusion Criteria: Previous muscular or neurophysiological diseases

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Test Group<br> | Other: muscle activation<br>* activation of the muscle quadriceps femoris<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Identification of a potential Force enhancement by complex muscle activity with a high relevance for everyday life, for example more agile leg stretching (knee bend). |  | 12 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evidence of existence of the force enhancement by deliberately activated, great human muscle by sub-maximal activation |  | 12 months | 
| Correlation between typ of muscle fiber and force enhancement in vivo |  | 12 months | 
| Analysis of the alternation of length of the muscle fiber during and after excentric extension for the differentiated explanation of in vivo mechanism excentric and post-excentric strength |  | 12 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Functionality, Deliberately, Activated, Quadriceps, Femoris, During, After, Active, Extension