The purpose of this study is to evaluate the efficacy of diclofenac potassium 25 mg tablet compared with placebo taken three times a day in subjects with acute ankle sprains under 'in-use' conditions, in particular with regard to pain relief.

Inclusion Criteria:

• Male or female aged 18 years and over.
• Acute sprain of the lateral ankle, Grade I-II, meeting baseline pain intensity level.
• Injury within past 12 hours.

Exclusion Criteria:

• Pain medication was taken within the 6 hours that precede randomization.
• During the past 3 months: Grade I-III sprain of the same ankle.
• During the past 6 months: Grade II-III sprain, any other significant injury (such as fracture or torn ligament), or surgery (except for skin or nails) of the same ankle or foot.
• Pain or instability in the same ankle attributable to previous ankle sprain or any other trauma.
• Ankle sprain attributable to a known disease affecting the ligaments, such as ligament hyperlaxity due to connective tissue disease (e.g., Marfan's syndrome, Down's syndrome, Ehlers-Danlos syndrome).