Related Experiment Video
Updated: May 10, 2026
Muscle Imbalances: Testing and Training Functional Eccentric Hamstring Strength in Athletic Populations
Published on: May 1, 2018
Factors associated with paraspinal muscle asymmetry in size and composition in a general population sample of men
Maryse Fortin1, Yan Yuan, Michele C Battié
1M. Fortin, BSc, CAT(C), PhD candidate, Common Spinal Disorders Research Group, Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Alberta, Canada.
Background:
Paraspinal muscle asymmetry in cross-sectional area (CSA) and composition have been associated with low back pain and pathology. However, substantial multifidus muscle asymmetry also has been reported in men who were asymptomatic, and little is known about other factors influencing asymmetry.
Objective:
The goal of this study was to identify behavioral, environmental, and constitutional factors associated with paraspinal muscle asymmetry.
Design:
A cross-sectional study of 202 adult male twins was conducted.
Methods:
Data were collected through a structured interview, physical examination, and magnetic resonance imaging. Measurements of multifidus and erector spinae muscle CSA and the ratio of fat-free CSA to total CSA were obtained from T2-weighted axial images at L3-L4 and L5-S1.
Results:
In multivariable analyses, greater asymmetry in multifidus CSA at L3-L4 was associated with lower occupational physical demands and less disk height narrowing. Handedness was the only factor associated with multifidus muscle CSA asymmetry at L5-S1. For the erector spinae muscle, greater age, handedness, and disk height narrowing were associated with CSA asymmetry at L3-L4, and sports activity, handedness, disk height narrowing, and familial aggregation were associated with CSA asymmetry at L5-S1. In multivariable analyses of asymmetry in muscle composition, familial aggregation explained 7% to 20% of the variance in multifidus and erector spinae muscle side-to-side differences at both levels measured. In addition, handedness and pain severity entered the model for erector spinae muscle asymmetry at L5-S1, and disability, handedness, and disk height narrowing entered the model for multifidus muscle asymmetry at L5-S1.
Limitations:
Reliance on participants' recall for low back pain history, occupation, and physical activity levels was a limitation of this study.
Conclusions:
Few of the factors investigated were associated with paraspinal muscle asymmetry, and associations were inconsistent and modest, explaining little of the variance in paraspinal muscle asymmetry.
Related Concept Videos
01:18Axial and Appendicular Muscles
Axial Muscles
Axial muscles, situated along the body's midline, are intricately connected to the axial skeleton, which includes the skull, spine, ribs, and sternum. These muscles facilitate facial expressions and play a...
01:12Alterations in Muscle Tone ll
01:20Disorders of the Male Reproductive System
Prostate disorders are another major concern. These conditions can impair urinary flow due to the prostate's location around the urethra. Symptoms...
01:28Disorders of the Skeletal Muscle
Musculoskeletal disorders
Musculoskeletal disorders involve injuries and conditions affecting the skeletal muscles and associated connective tissues. These disorders can arise from acute biomechanical stresses or chronic overuse and can occur across different age groups. Common injuries include sprains, fractures, and muscular strains, often resulting from...
01:11Alterations in Muscle Tone lll
01:27Muscles of the Vertebral Column
Superficial Layer:
The superficial layer consists primarily of the splenius muscles, which include the splenius capitis and splenius cervicis. These muscles are mainly responsible for the head and cervical spine movements, including extension, rotation, and lateral bending. The splenius capitis...