Muscles and Movement

Muscles and movement are explained through a practical clinical perspective: movement patterns influence how muscles function, and muscles should not be viewed in isolation. A key distinction is made between short structural muscles, such as contractures, and short active muscles, which are more common and may respond to neurophysiological relaxation, hold-relax techniques, and especially eccentric training to improve range and muscle length. The main actions and common dysfunctions of several muscles are reviewed, including the external obliques, erector spinae, latissimus dorsi, quadratus lumborum, psoas, TFL, gluteal muscles, deep lateral hip rotators, and hamstrings. The explanation connects each muscle to pelvic tilt, lumbar extension or rotation, hip control, and pain or compression patterns in the back and hip. Special attention is given to how posture and movement strategies can reduce or increase muscle dominance, such as sway-back posture reducing glute activity or hamstrings taking over during stair climbing and step-ups. Learners can expect a detailed overview of how muscle activity relates to alignment, joint motion, and common compensatory patterns.