Muscles' Automatic Action and Braking: Why Trigger Points Form

Trigger points arise from a disruption in the muscles' protective and relaxation mechanisms: excessive fatigue, injury or emotional tension cause muscle spindles to contract continuously, while the Golgi tendon system loses its braking effect, leaving the muscles persistently tight and forming stiff bands. Pressing on them produces local soreness, swelling and pain, and may even trigger pain in other parts of the body; sustained increases in tension can lead to tendon inflammation, with symptoms of redness, swelling, heat and pain.