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Updated: May 7, 2026

Muscle Imbalances: Testing and Training Functional Eccentric Hamstring Strength in Athletic Populations
Published on: May 1, 2018
Variability and distribution of muscle strength and its determinants in humans
Georgina K Stebbings1, Christopher I Morse, Alun G Williams
1Centre for Genomic Research into Exercise, Performance and Health, Institute for Performance Research, Manchester Metropolitan University, Crewe Green Road, Crewe, Cheshire, CW1 5DU.
Introduction:
Inter-individual variability in measurements of muscle strength and its determinants was identified to: (1) produce a normative data set describing the normal range and (2) determine whether some measurements are more informative than others when evaluating inter-individual differences.
Methods:
Functional and morphological characteristics of the vastus lateralis were measured in 73 healthy, untrained adult men.
Results:
Inter-individual variability (coefficient of variation) was greater for isometric maximal voluntary contraction (MVC) torque (18.9%) compared with fascicle force (14.6%; P=0.025) and physiological cross-sectional area (PCSA; 17.2%) compared with anatomical cross-sectional area (ACSA, 13.0%; P<0.0005). The relationship between ACSA and isometric MVC torque (r(2) =0.56) was weaker than that between PCSA and fascicle force (r(2) =0.68).
Conclusions:
These results provide a normative data set on inter-individual variability in a variety of muscle strength-related measurements and illustrate the benefit of using more stringent measures of muscle properties. Muscle Nerve 49: 879-886, 2014.
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