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Comparison of Eccentric Exercise and Static Stretching on Muscle Flexibility

Not Applicable
Not yet recruiting
Conditions
Muscle Stretching Exercise
Range of Motion, Articular
Interventions
Other: Control Group
Other: Nordic Hamstring Eccentric Exercise Training
Other: Passive Hamstring Static Stretching Training
Registration Number
NCT06469346
Lead Sponsor
Universidad de La Frontera
Brief Summary

Background: Muscle flexibility is a fundamental physical quality for body development, daily life and sports activities, and also for maintaining muscle quality during aging. Limited flexibility leads to an increased prevalence of musculoskeletal injury in general population and longer return to sports activities.

Among the existent strategies to increase muscle flexibility in sports training and physical rehabilitation, static stretching is commonly used by health and physical activity professionals. Its effectiveness in increasing flexibility has been widely demonstrated; however its effects on muscle strength and power remains controversial.

Therefore, eccentric resistance exercise has been proposed as an effective intervention for increasing muscle flexibility through structural changes on muscle architecture (pennation angle and fascicle length) with the additional benefit of resistance training on muscle strength and power. Nonetheless, its unknown if the increase in muscle flexibility through eccentric resistance exercise could be similar to what has been previously demonstrated with static stretching.

Detailed Description

Hypothesis: The increase in hamstring flexibility after 6 weeks of eccentric resistance training in young males would be similar compared to 6 weeks static stretching training in the same population.

Goals: The primary aim of the study is to compare the effectiveness of 6 weeks eccentric resistance training vs 6 weeks static stretching training on hamstring flexibility in young males.

Specific Goals: Determine the effect of 6 weeks excentric exercise training and 6 weeks static stretching training on unilateral maximal isometric voluntary strength between both groups

To compare the effect of 6 weeks excentric exercise training and 6 weeks static stretching training in structural changes on muscle architecture (pennation angle, fascicle length and muscle thickness).

Methodology:

Study design: Forty two young males between 18 and 35 years will be divided into three groups: hamstring eccentric resistance training group (EEG, n=14), hamstring static stretching group (SSG, n=14) and control group (CG, n=14). Volunteers of eccentric resistance training group will be subjected to 6 weeks of Nordic hamstring exercise (3x/wk), while volunteers of static stretching group will be subjected to 6 weeks of hamstring passive static stretching (3x/wk). Control group will not attend any type of intervention. Before and after 6 weeks of training, Knee Extension Angle and Sit and Reach test will be performed for measuring hamstring flexibility. Unilateral Hamstring Isometric Maximal Voluntary Strength will be determined by load cell force transducer, and pennation angle, fascicle length and muscle thickness of Long Head Biceps Femoris will be conducted through muscle ultrasonography

Study parameters/endpoint:

The main study endpoint is the increase in hamstring flexibility assessed with Knee Extension Angle and Sit and Reach Test.

Secondary endpoints include Unilateral Hamstring Isometric Maximal Voluntary Strength (IMVS) and Architectural changes in Long Head Biceps Femoris muscle.

Other parameters include age, body weight, body height, body mass index (BMI), level of physical activity.

Expected results: With the proposed project, the investigators expect that eccentric exercise training will increase hamstring muscle flexibility at similar level compared with static stretching training. The findings will define the potential of eccentric exercise training on muscle flexibility in healthy participants. These results could expand the benefits of this type of exercise training focused on being included in populations with limited mobility such as elderly and injured populations

Recruitment & Eligibility

Status
NOT_YET_RECRUITING
Sex
Male
Target Recruitment
42
Inclusion Criteria
  • Masculine University students between 18 and 35 years old
  • Physically Inactive considering physical activity recommendations from World Health Organization
  • Bilateral hamstring muscle stiffness defined as <160° in passive Knee Extension Angle Test
  • Body Max Index 18,5 < BMI < 24,9 kg/m2
Exclusion Criteria
  • Lower back and lower limb (hip, thigh, knee, ankle) musculoskeletal injury in the last 12 months.
  • Hamstring injury (strain, tendinopathy, tendon avulsion) previously during the period of life
  • Dietary anabolic supplements consumption
  • Musculoskeletal, cardiovascular, respiratory o similar health condition that limits participation on physical activity programs
  • Regular resistance training (2 or more times per week, carrying out progressive training) in the previous 6 months
  • Smoker (1 cigarette per day)

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Control GroupControl GroupThese participants will not be under any type of treatment during the intervention protocol
Eccentric Exercise Group (EEG)Nordic Hamstring Eccentric Exercise TrainingThese participants will be subjected to 6 weeks of Nordic hamstring eccentric exercise (3 times per week)
Static Stretching Group (SSG)Passive Hamstring Static Stretching TrainingThese participants will be subjected to 6 weeks of passive static stretching on hamstring muscle (3 times per week)
Primary Outcome Measures
NameTimeMethod
Knee Extension AngleBefore and after 6 weeks of training

The degree changes in passive knee extension will be assessed using Passive Knee Extension Angle Test after intervention

Sit-and-ReachBefore and after 6 weeks of training

The distance (in centimeters) of change on functional posterior chain flexibility will be obtained in Sit-and-Reach Test after intervention

Secondary Outcome Measures
NameTimeMethod
Maximal Isometric Voluntary StrengthBefore and after 6 weeks of training

Change in unilateral isometric hamstring strength will be evaluated with load cell force transducer after intervention

Long Head Biceps Femoris Pennation AngleBefore and after 6 weeks of training

Change in pennation angle will be measured using muscular ultrasound after intervention

Long Head Biceps Femoris Fascicle LengthBefore and after 6 weeks of training

Change in fascicle length will be measured using muscular ultrasound after intervention

Long Head Biceps Femoris Muscle ThicknessBefore and after 6 weeks of training

Change in muscle thickness will be measured using muscular ultrasound after intervention

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