Key Causes and Symptoms:Intercostal Muscle Strain: Muscles between the ribs get overstretched or torn due to twisting, reaching, or intense exertion.Costochondritis: Inflammation of the cartilage connecting ribs to the breastbone, often triggered by pressure or heavy exertion.Symptoms: Sharp, stabbing, or dull pain in the ribs (especially when breathing deeply, coughing, or moving).