When utilizing thermal modalities, what is not an expected physiological effect?

The expected physiological effects of thermal modalities primarily include pain relief, increased circulation, increased metabolic activity, and muscle relaxation. When applying thermal modalities, such as heat packs or warm water baths, the intent is often to enhance circulation by dilating blood vessels, which promotes increased blood flow to the area being treated.

Increased metabolic activity is another key effect; warmth speeds up cellular processes, which can stimulate healing and tissue repair. Muscle relaxation occurs as heat reduces muscle tension, minimizes spasms, and improves overall flexibility.

Therefore, decreased circulation would not be an expected physiological effect of thermal modalities. Instead, heat is known to cause vasodilation, resulting in increased blood flow, not a reduction. This makes decreased circulation an incorrect answer since it contradicts the primary effects of applying heat.