Methods	RCT, DB, parallel groups Gel massaged into skin over affected heel three times daily after cleaning with soap and water for up to 21 days Assessment at baseline, 7, 21 days
Participants	Acute achilles heel tendinitis (not associated with continuous pain at rest or >1 month history) N = 243 (227 analysed for efficacy) M/F not reported Mean age 29 years Baseline pain: ~10% had <26 mm on palpation of tendon, ~30% had mild or no pain on dorsifexion of foot Exclusions: failure to meet inclusion criteria, major protocol violations, failure to take study medication for full duration
Interventions	Niflumic acid gel 2.5%, 3× 5 g daily, n = 117 Placebo gel, n = 110 No other analgesics and antiinflammatories, physiotherapy or supportive measures allowed
Outcomes	PGE: 5 point scale (responder = “good” or “very good”) Pain improved or disappeared on dorsiflexion Adverse events Withdrawals and exclusions
Notes	Oxford Quality Score: R1, DB1, W1. Total = 3/5 Oxford Validity Score: 12/16
Risk of bias
Bias	Authors’ judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not described
Allocation concealment (selection bias)	Unclear risk	Not described
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Not described