Longitudinal arch stress distribution of the foot following plantar ligament injury

Objective To measure stress distribution of the main bone architecture of the normal adult cadaveric foot and discuss the effect of plantar ligament injury on stress distribution. Methods Seven fresh adult cadaveric feet were used and 10 strain gauges attached to the bones of the longitudinal foot arch,including the calcaneus,navicular,medial cuneiform,1-5 metatarsal trunk,the distal part of the tibia and fibular,respectively.After the loading Was added to 700 N by almighty test machine,resistance strainmeter was used to measure surface strain of these bones.The results were processed statistically. Results The strain was varied based on different bone segments attached and increased with loading.Tensile force was always found at the medial part of the navicular,the distal part of the tibia and fibular,while the others showed compression all the time.Peak strain was found at calcaneus.followed by the second and third metatarsal.Strain on the surface of the bone segments changed greatly with different ligament injury(P＜0.05).Conclusion The bone surface stress of the longitudinal foot arch changes significantly when the plantar ligament is injured. Key words: Foot injury; Ligaments;  Fracture,stress;  Biomechanics;  Foot longitudinal arch