Background The majority of sporting injuries are clinically diagnosed using history and physical examination as the cornerstone. There are no studies supporting the reliability of making a clinical diagnosis of medial tibial stress syndrome (MTSS).

Aim Our aim was to assess if MTSS can be diagnosed reliably, using history and physical examination. We also investigated if clinicians were able to reliably identify concurrent lower leg injuries.

Methods A clinical reliability study was performed at multiple sports medicine sites in The Netherlands. Athletes with non-traumatic lower leg pain were assessed for having MTSS by two clinicians, who were blinded to each others’ diagnoses. We calculated the prevalence, percentage of agreement, observed percentage of positive agreement (Ppos), observed percentage of negative agreement (Pneg) and Kappa-statistic with 95%CI.

Results Forty-nine athletes participated in this study, of whom 46 completed both assessments. The prevalence of MTSS was 74%. The percentage of agreement was 96%, with Ppos and Pneg of 97% and 92%, respectively. The inter-rater reliability was almost perfect; k=0.89 (95% CI 0.74 to 1.00), p<0.000001. Of the 34 athletes with MTSS, 11 (32%) had a concurrent lower leg injury, which was reliably noted by our clinicians, k=0.73, 95% CI 0.48 to 0.98, p<0.0001.

Conclusion Our findings show that MTSS can be reliably diagnosed clinically using history and physical examination, in clinical practice and research settings. We also found that concurrent lower leg injuries are common in athletes with MTSS.