Influence of Age and Gender on Muscular Co-activation of Extremities: A Mini-Review

Background: The differences in muscle co-activations as they apply to both age and sex are usually dependent on neurophysiological, as well as hormonal alterations. However, there is need to understand the implications of age and gender in agonist-antagonist muscle co-activations in the extremities from a holistic perspective. Aim: The review focused on the assessment of co-activation patterns in agonist-antagonist muscle pairs commonly found in both upper and lower limb regions of the body with respect to both age and gender differences. Methods: We searched for related studies dating 2010 – 2024 on multiple databases such as PubMed, Scopus, Web of Science, and Google Scholar using keywords "muscle co-activation," "age," "gender," and "extremities". Inclusion criteria involved studies that involved human participants across different age groups (children, young adults, elderly). Findings were categorized based on age and gender differences to identify patterns in co-activation of selected muscles. Results: The outcomes revealed by this study showed that there exist both age- and gender–related changes in agonist and antagonist muscle co-activations. For instance, age-related differences were observed during co-activation of the quadriceps and hamstrings, triceps and biceps, rectus abdominis and erector spinae, and tibialis anterior and gastrocnemius-soleus, during limb movement. Furthermore, gender differences were seen during limb movements between quadriceps and hamstrings, deltoid and rotator cuffs, and biceps brachii and triceps brachii muscles. Conclusion: It can be concluded that the review provides an understanding on the impact of both age and gender in promotion of muscle performance, joint stability, and functional outcomes in both healthy adults and the elderly, and people who could be affected with limb and associated forms of musculoskeletal disorders.