Effects of tibial rotation on Ober's test and patellar tracking

• This study examined the effects of tibial rotation on iliotibial band (ITB) flexibility and patella position.
• Adduction angle was significantly greater in the neutral tibial position than in external rotation.
• The patella-condyle distance was significantly greater in the neutral position than in internal rotation.
• These findings support that tibial rotation influences the flexibility of the ITB and patella positions.
• Therapists should consider tibial rotation when measuring adduction angles.

BackgroundThe purpose of this study was to investigate the effects of tibial position on ITB flexibility and patellar position.MethodsA total of 31 asymptomatic subjects (21 males, 10 females) were recruited for this investigation. Adduction angle was measured by Ober's test, and PCD was measured by ultrasonography in three different tibial rotation conditions: N, IR, and ER.ResultsRepeated measures ANOVA revealed a significant difference in adduction angle and PCD among three different tibial positions (P < 0.05). Adduction angle was significantly greater in the N tibial position than in ER (P < 0.05). The PCD was significantly greater in N position than in IR (P < 0.05). However, the PCD was significantly smaller in IR compared with the N position (P < 0.05).ConclusionsThese findings support that tibial rotation influences the flexibility of ITB and patellar positions. Therefore, excessive tibial rotation can cause inappropriate patellar positions that eventually lead to knee injury. Therapists should consider tibial rotation when measuring adduction angles because tibial rotation can change Ober's test results and contribute to the consistency of ITB length measurements.Level of evidenceLevel IV.