Muscle Tension

Persistent tightness, stiffness, or a feeling of knotted muscles, most often in the neck, shoulders, and jaw. The common drivers are stress, prolonged posture (screens, desks), poor sleep, and bruxism — with magnesium deficiency playing a role for some people, though the evidence for supplementation is weaker than the marketing suggests.

Evidence synthesis: Magnesium is involved in muscle relaxation at the cellular level (it competes with calcium at the neuromuscular junction), and deficiency causes cramps and spasms — but trials of magnesium for general muscle tension or chronic neck/shoulder pain are small and inconsistent, with the strongest data limited to nocturnal leg cramps in specific populations. Exercise and stretching have robust evidence for reducing musculoskeletal tension, and progressive muscle relaxation has solid trial support for stress-related tension. Bruxism (jaw clenching) is a major under-recognised driver of neck, shoulder, and temple tension, strongly linked to stress and sleep disruption. Posture-related tension from prolonged sitting is the dominant mechanical cause in desk workers.