Research on the Short-term Characteristics of Plantar Pressure Distribution and Balanceafter Anterior Cruciate Ligament Reconstruction

Objective: Anterior cruciate ligament(ACL) injury is one of the common sports injuries. The investigation of the characteristics of static and dynamic plantar pressure distribution and balance after ACL reconstruction will provide theoretical references for clinical rehabilitation. Based on the gender difference, the footprints were used to exclude the subjects with foot malformation(flat foot or high arch foot). Methods: 32 patients(21 males and 11 females) who was able to walk at 6~8 weeks after ACL reconstruction were recruited in this study, and 26 normal subjects(14 males and 12 females) without lower limb injury to were set as control group. The parameters of plantar pressure distribution and balance ability were collected from all subjects for analysis.Results: 1) No significant difference was found in static plantar pressure between the ACL reconstruction group and control group.2) The characteristics of dynamic plantar pressure: the percentage of lateral heel area in the affected region was significantly smaller;compared with the healthy region, the area percentage and load of the first metatarsal and 2-3 metatarsal were significantly higher,while the load of the inner and outer heel were significantly lower; compared with control group, the load of lateral heel was decreased significantly. 3) The affected region spent significantly more time in FFP(foot flat phase) but less time in FFPOP(forefoot push off phase) when compared with healthy region; compared with control group, the affected region spent significantly more time in FFCP(forefoot contact phase) and FFP but less time in FFPOP. 4) The affected region had significantly smaller ellipse area, but the L/S value was significantly higher than that of the healthy region. Conclusion: 1) The static plantar pressure was recovered 6~8 weeks after ACL reconstruction, but the dynamic walking showed insufficient pedal, forward movement of the whole center of gravity. The maximum and average pressure of reconstruction side was decreased significantly, and the walking speed slowed down and the total time of support phase was increased. 2) The balance ability of one-leg standing was decreased at 6~8 weeks after ACL reconstruction, so proprioception and muscle strength training of lower limbs should be strengthened during rehabilitation.