RESEARCH REPORT POSTER DISPLAY

QUANTITATIVE ANALYSIS OF DISTAL TIBIOFIBULAR JOINT MOBILIZATION: A CADAVER STUDY. Fujii M¹, Miyamoto S², Muraki T¹, Suzuki D³, Teramoto A⁴, Uchiyama E³, Aoki M²; ¹Graduate School of Health Sciences, Sapporo Medical University, Sapporo, Japan. ²Department of physical therapy, Sapporo Medical University, Sapporo, Japan. ³Department of anatomy, Sapporo Medical University, Sapporo, Japan. ⁴Department of orthopedic, Sapporo Medical University, Sapporo, Japan

PURPOSE: Although joint mobilization is an effective treatment procedure for limited range of ankle dorsiflexion, selection of an appropriate joint mobilization technique remains controversial. This research aims to evaluate the relationship between the directions of application of the mobilization force on the distal fibula and the amount of distal fibular motion. RELEVANCE: It is critical to assess the joint movement when mobilizing the distal tibiofibular joint because selection of an appropriate mobilization technique may facilitate adequate distal tibiofibular joint play. PARTICIPANTS: Seven normal frozen-thawed cadaver legs (5 males, 2 females; mean age of the specimens, 79.9 years, range 67-98) were used. METHODS: Each foot was fixed on a jig at 10° plantar flexion. All measurements are monitored by 3Space tracking system (Polhemus, USA). Prior to the experiment, the range of ankle motion and the fibular movements were measured. Subsequently, the distal fibula was mobilized in four directions (posterior, posterosuperior, posterolateral, and superior). For simulating mobilization techniques, a 19.6N traction force was applied to the distal fibula by inserting a bone anchor into the lateral malleolus. Displacements along the coordinate axes of the fibula (X, anteroposterior; Y, mediolateral; and Z, superoinferior) were measured while the traction force was applied. ANALYSIS: Data analysis was performed using the two-way analysis of variance with repeated measures. Bonferroni’s correction was used for conducting multiple comparisons. RESULTS: Application of the traction in the posterior, posterosuperior, posterolateral, and superior directions caused displacements of 0.07±0.04, 0.05±0.05, 0.20±0.09 and 0.03±0.02mm, respectively, along the Z axis. The displacement caused by applying traction in the posterolateral direction was significantly larger than those caused by applying traction in the other directions (p < 0.01). There was no significant difference between any directions with regard to the distal fibular displacements along the X and Y axes. CONCLUSIONS: In this experiment, the distal fibula moved toward similar directions during ankle dorsiflexion. While applying tractions that simulate mobilization techniques, significant amount of fibular displacement was achieved by applying tractions in posterolateral. Therefore, it was proved that posterolateral traction had certain beneficial effects on joint play restriction, thereby improving the range of ankle dorsiflexion. IMPLICATIONS: Our findings would be useful to treat limited range of ankle dorsiflexion caused by the contracture of the distal tibiofibular joint. KEYWORDS: Distal tibiofibular joint, Joint mobilization, Limited range of dorsiflexion. FUNDING ACKNOWLEDGEMENTS: No grant or funding was received for this project. CONTACT: m-fujii0120@hotmail.co.jp

ETHICS COMMITTEE: Institutional Review Board of Sapporo Medical University