Step 1: Understanding microwave diathermy.
Microwave diathermy is a therapeutic technique that uses microwave radiation to generate heat in deep tissues to relieve pain and improve blood circulation. However, this technique is contraindicated in certain conditions.
Step 2: Contraindications.
- (A) Pregnancy: Microwave diathermy should not be used in pregnant women because it can harm the developing fetus.
- (B) Tumour: The use of microwave diathermy in areas with cancerous growth can promote tumour growth.
- (C) Sprain: Microwaves may worsen inflammation in acute injuries such as sprains.
- (D) Infections: Infected tissues may become more susceptible to further injury or complication.
Step 3: Conclusion.
Therefore, the correct answer is (1), as pregnancy, tumour, and sprain are the major contraindications.