Muscle stiffness
Muscle stiffness is a feeling of tightness, soreness, or difficulty moving comfortably in a muscle or muscle group.
In everyday words
Someone might describe their muscles as stiff after an unfamiliar activity or after staying in one position for a long time. That describes how they feel, rather than identifying one particular cause.
What to keep in mind
Stiffness is different from weakness, which means reduced ability to produce force. Persistent or worsening stiffness, or stiffness with fever, swelling, or new weakness, warrants medical advice.