Unilateral Stretch Crossover Effect RCT

Study Overview
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Brief Summary
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The crossover-effect within resistance- and strength training is more or less confirmed with multiple studies showing similar results. The studies shows an increase in muscle strength within the contralateral extremity being exercised. Regarding muscle length or mobility (flexibility) the crossover-effect have not been studied. For a person to gain an increase in muscle strength mobility training in the form of stretching and flexibility training of our skeletal muscle is a common exercise. However, the evidence are scare and there are only a few studies comparing the effect of prolonged static stretching (> 90 sec) and dynamic flexibility training as to which of these methods has the best length-enhancing effect over time. The purpose of this study is to compare the crossover-effect of eight weeks of oneleg dynamic flexibility training versus oneleg prolonged static stretching versus a nonstretching controlgroup on mobility in the hamstring muscles in adults with reduced mobility of the hamstring muscle. The aim is also to compare the sustained effect of flexibility training between the two groups, eight weeks after completion of the intervention.

Official Title
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Crossover-effect of Unilateral Dynamic Versus Static Stretch of Hamstrings Muscle on Hamstrings Muscle Length - a Randomized Controlled Trial

Conditions
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Stretch, Muscle Tightness

Intervention / Treatment
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* Other: Strecthing


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Passiv straigth leg raise < 70 degrees Read and understand swedish Exclusion Criteria: Injuries within the hamstrings muscle past 3 month Disabilities within the muscloskeletal system (i.e. lower back, thoracic spine, cervikal spine, hip, knee, ankle, fot) affecting the participants life Neurological, inflammatoric or heart-diseases Nociplasic pain disorders Medication with possibility affecting muscle strength of flexibility Positive neurodynamic test of the lower extremity

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 50 Years

Sexes Eligible for Study
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All

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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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Dynamic stretching<br> | Other: Strecthing<br>* Comparing the crossover-effect of dynamic versus static stretching<br>|
| Experimental: Static stretching<br> | Other: Strecthing<br>* Comparing the crossover-effect of dynamic versus static stretching<br>|
| Active Comparator: Controll<br> | Other: Strecthing<br>* Comparing the crossover-effect of dynamic versus static stretching<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Passiv straigth leg raising | Muscle length of the hamstrings muscle will be measured via degress of hip flexion at a passive straigth leg raise of the lower extremity. One leg at a time. | 5 minutes | 
| Active knee extension | The person will lay supine with a 90 degress of hip flexion towards a bar against the thigh. Thereafter the person will perform an active knee extensor as far as possible and the degrees of kneeflexion will be measured. | 5 minutes |