Heat is generally better for relieving back pain caused by muscle knots, while ice is better for inflammation . Heat can aggravate inflammation, while cold can stiffen tension in muscles, states PainScience.com.
The majority of back injuries are muscle knots, or trigger points for pain in your muscles, notes PainScience.com. The cold, when applied to these points, generally stiffens the muscles on contact, worsening the condition. These trigger points typically respond better to heat. Ice is better used for surface inflammation of the back or an evident muscle strain, which is much rarer than muscle knots. Indicators of muscle strain include a sudden moment of pain after intense stretching or physical exertion, a spot on the back that is extremely sensitive to touch, or puffy, hot skin.