A Biomechanical Analysis Of The Movement Of The Lower Limb Of A Football Shoe With Different Soles

Objective: The purpose of this study was to investigate the effect of different outsole hardness of turf cleats shoes on sports performance and non-contact injuries of lower extremities.This study also provides scientific information for manufacturers to select appropriate shoe outsole.Methods: A total of 14 amateur soccer players participated in the tests.Participants were asked to complete tasks of straight-line acceleration and 45° left sidestep cutting respectively at the speed of 5.0±0.2m/s on artificial turf under laboratory condition.They selected shoes with soft outsole(SO),medium hardness outsole(MO)and hard outsole(HO)randomly A Vicon three dimension motion analysis system was used to capture kinematic data and a Kistler force platform was used to record the ground reaction force,Novel Pedar-X insole plantar pressure measurement system was utilized to collect the plantar pressure(peak pressure,peak force and force-time integral)in specific anatomical areas.Results: Peak pressure,peak force and force-time integral in medial forefoot(MFF)of SO were significantly smaller than MO during stance phase in straight-line acceleration.During stance phase in 45° left sidestep cutting,there were no significant differences in ankle,knee and hip joints in the sagittal plane.During landing phase,the average vertical loading rate as well as peak pressure,peak force and force-time integral in the heel(H)and lateral forefoot(LFF)of HO were significantly higher than SO;while peak pressure,peak force and force-time integral in the medial forefoot(MFF)of SO were significantly higher than HO.Conclusions: In straight-line acceleration,MO shoes provide greater propulsive force with greater plantar pressure in MFF,which contributes to improve sports performance;In 45° left sidestep cutting,higher ground reaction force and plantar pressure of some areas could improve performance.However,this may also result in increasing risks of metatarsal stress fractures and plantar fasciitis.Design of soccer shoes outsole should base on features of lower extremity biomechanics such as soft material for the heel and medium material for the medial forefoot.