Muscle aches after an intense workout are common. Common problem areas are the shoulders, neck, and upper back. Pain in these areas can make it difficult to move your muscles, often putting an end to your workout. This pain or soreness can last for weeks or even months. This may be the result of muscle knots.
Muscle knots are points within a muscle where contracted fibers are unable to release and instead remain tightened. They can be described as irritable localized spots of tenderness in muscle tissue.
The medical term for muscle knots is myofascial trigger points (MTPS). Muscle knots can be the size of a pinhead to the size of a thumb.
Muscle knots can cause pain in two ways. The first is through latent trigger points, which are knots that only hurt when pressure is put upon them. The second way is through active trigger points, which are knots that actively producing pain along your neural pathways, sending pain to other parts of the body.
How do muscle knots form?
Muscle knots are caused by injury (physical stress), toxic exposure (chemical stress), nutritional deficiency, or even emotional stressors. Any of these causes can lead to the development of contracted taut bands of muscle tissue. Occasionally, they can be felt thought through the skin and may be painless, but eventually, they will begin to shorten and alter your movement patterns.
The muscles in your body contain hundreds of muscle fibers. They work by shortening actin and myosin filaments within them, essentially causing a contraction of the muscle. When you squeeze your muscles, you effectively push most of the blood away from the muscle area. While your body attempts to make up for this by increasing blood pressure and heart rate, this initial lack of localized blood in the muscle fibers results in a reduction of oxygen and nutrients, which the blood supplies.
Taut muscle bands begin to run low on energy, or ATP (adenosine triphosphate). When there is a lack of ATP available for muscle cells to use, this can manifest as fatigue or pain. Also, when muscles are in a constant state of contraction and blood flow to the area has stopped, they produce excess metabolic waste, sending pain signals to the brain.