OBJECTIVETo analyze micromovement of distal tihiofihular joints in different motion range of ankle joint ,and define the micromovement characteristic and range of distal tibiofihular joints.

METHODSTwelve normal Chinese were chosen. There were 9 males and 3 females, aged from 19 to 37 years old with an average (26.5 +/- 0.5) years. Detection terminals of laser photographic scanner were installed near the highest point between medial malleolus and lateral malleolos, the change of detection terminals on the position of dorsiflex, extension, introversion and eversion of ankle joint were scanned by 3D-laser scanner. The displacement of two detection terminals on the X ,Y and Z-axis (X-axis stands for the vertical-axis between coronal plane and Z-axis Y-axis stands for the vertical-axis between sagittal plane and Z-axis Z-axis stands for macroaxis of tibia).

RESULTSAlong with increased range of motion on the position of dorsiflex ,extension, introversion and eversion of ankle joint, the range of micromovement of distal tibiofibolar joints increased too. The max-displacement of X, Y and Z were respectively (1.04 +/- 0.12) mm, (1.70 +/- 0.16) mm and--(0.87 +/- 0.10) mm.

CONCLUSION3D-laser scanner can be used to determine the detailed displacement of distal tibiofibolar joint on the X , Y and Z, and measure the motion of distal tibiofibular joint. The method can be used to study the pathologic change of distal tibiofibular joint ,and provide basic biomechnics data for internal fixtor fitting for the characteristic of distal tibiofibular joint.