The phrase "muscular tightness" refers to a feeling of tension or stiffness in the muscles. It means that certain muscles are not relaxed and may be causing discomfort or limited movement. Full definition
Note: This practice is meant to relieve simple muscular tightness in your back, and it may be inappropriate for muscle spasms, disk injuries, sacroiliac - joint dysfunction, spondylolisthesis, or other back problems. (yogajournal.com)
This magical combination results in relieving muscular tightness and reducing the physical stress placed on bones and joints. (myobuddy.com)
Mom's milk supply, appropriate positioning at the breast, muscular tightness of the jaw and mouth, neck problems like torticollis, etc.. (themilkmeg.com)