The Bilateral Deficit Phenomenon, Functional and Dynamometric Assessment in Postmenopausal Women

Study Overview
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Brief Summary
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The bilateral deficit phenomenon (BLD) is defined as an inability of the neuromuscular system to generate maximal force when two homonymous limb operate simultaneously (bilateral contraction) with respect to the force developed when both limbs acts separately (unilateral contraction). From an applied perspective, movement patterns of bilateral homonymous limb are often developed during activities of day living, e.g. rising from a chair or opening a jar. The BLD can be considered an intrinsic property of the human neuromuscular system but could be enough important to constitute a performance-limiting factor for postmenopausal women that involves a degenerative loss of muscular strength. Therefore, a specific analysis of this phenomenon and its relation with activities of daily living, such as climbing a step and rising from a chair, is crucial for detecting variables of neuromuscular performance and develop strategies to minimize the loss of strength.

Detailed Description
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20 postmenopausal women unexperience in strength training or resistance training, without musculoskeletal, neurological diseases, and cardiovascular limiting-diseases were recruited. Maximum strength of lower limbs during leg-press exercise was measured for future analysis. The force-time curves were measured during climbing a step and rising from a chair. A fragility phenotype test was applied to the subjects to determine frailty phenotype classification, including; weight loss of greater than 10 lbs in the past 12 months, maximal handgrip strength, time to walk 15-ft at usual pace, self-reported leisure time physical activity, and self-reported exhaustion. The anthropometric measurements were performed by dual energy X-ray absorptiometry.

Official Title
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The Bilateral Deficit Phenomenon, Functional and Dynamometric Assessment in Postmenopausal Women

Conditions
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Postmenopausal Syndrome, Muscle Weakness

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Postmenopausal women Exclusion Criteria: Unexperienced in strength training or resistance training. Not musculoskeletal diseases. Not neurological diseases. Not cardiovascular limiting-diseases. Not fragility or pre-fragility phenotype.

Ages Eligible for Study
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Minimum Age: 50 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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Female

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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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Assess the maximum force of lower limbs during bilateral and unilateral contraction |  | Screening visit | 
| Assess the force-time curve during climbing a step |  | Screening visit | 
| Assess the force-time curve during climbing rising from a chair |  | Screening visit | 
| Assess bone mineral-free lean tissue mass by dual energy X-ray absorptiometry |  | Screening visit | 
| Assess the fragility phenotype of the subjects |  | Screening visit | 
| Assess the rate of force developed in time intervals (0-50, 50-100, 100-150ms) of lower limbs during bilateral and unilateral contraction |  | Screening visit | 
| Assess fat-tissue mass and lean-tissue mass composition |  | Screening visit | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Musculoskeletal Physiological Phenomena, Postmenopause, Muscle Strength, Absorptiometry, Photon