A Comparative Study On The Biomechanical Characteristics Of Female College Students Running Barefoot And Wearing Shoes

Study Objective: Running has become a popular means of training or exercise,and has been regarded as one of the most important recreational activities, the population of running(running frequency ? 50 times a year)in China during2014-2015 increased 10.6%, the research shows that moderate intensity(150 min)running training can reduce the incidence of coronary heart disease by 35%, reduce the incidence of ? diabetes by 50%. But with the popularity of running, it has also caused high incidence of lower limb injury(19-78%). The larger foot landing impact is the main reason of sports injury, among which knee, ankle injury is very common. As barefoot running and shod running has the biomechanical differences(including the vertical load, reduce the landing change kinematics parameter and muscle activity patterns, etc.),barefoot running is thought to be a means of preventing excessive use injury. Therefore, to analysis the biomechanical differences of barefoot and shod conditions, evaluate and measure the differences of two conditions with reliable biomechanical parameters(kinematics, dynamics and electromyography), which has important significance to the prevention of sports injury and running training theory.Study Methods: 1). 3-d video analytic method: The process of using barefoot running and shod running were recorded with two cameras(shooting frequency 50Hz), with 3D Signal TEC software we made a analysis on the technique and obtain relevant kinematics parameters. 2). With Kistler three-dimensional load(sampling frequency is 1000 Hz), using Bioware signal data processing of the original software,obtain kinetic parameters. 3). The methods of EMG testing: use DELYSY wireless s EMG system, the sampling frequency is 1000 Hz. Selected Tibialis anterior,Gastrocnemius, Vastus lateralis, Biceps femoris of the left side. Using EMGworks obtain relevant EMG data, selecting integral electromyography(IEMG) and amplitude percentage as the indicator. 4) use Spss16.0 to make statistics analysis of the data obtained.Study Conclusions:1). Kinematics results: Barefoot running pattern is forefoot strike(FFS),while the shod running is rarefoot strike(RFS),the step time of barefoot running is 0.335 s,and the step of shod running is 0.365s; the step frequency of barefoot running is 180.05step/min,the step frequency of shod running is170.38step/min; the contact time of barefoot running is 0.217 s, lower than that of shod running(0.249s); compared with the barefoot running the left forefoot on the ground moment(B1),the shod running left heel touch on the ground moment has more knee flexion; the left heel touch on the ground moment of barefoot running(B2)and shod running forefoot touch on the ground moment(S2), running with shoes have greater ankle plantar flexion; compared to bare feet run(155.31 °) of the knee joint angle is smaller than 161.60 ° of shod running, ankle angles greater than running shoes, barefoot ran B3 time compared with shoes run S3 moment, found that the hip joint angle of barefoot running is smaller than shod running, barefoot running the forefoot off the ground moment(B4) and running shoes feet off the ground in front of his left foot(S4), compared to more knee flexion, and knee joint angle has very significant difference; minimum value of hip angle barefoot running(146.21 °)is less than that of shod running(152.63 °), the hip joint angle change values(27.97 °) is greater than the shod running(21.49 °); Bare feet run of knee joint Angle is the maximum value and change should be less than running shoes, minimum value is greater than the knee joint Angle barefoot ran the minimum value of knee joint Angle;maximum angles of minimum value and change values are higher than shod running.2) kinetics test results: F- t curve of barefoot running is the smooth of the single peak curve, and the curve of shod running is as in the vertical direction have two fluctuation of double peak curve. Barefoot running B1 and shod running S1 moments of three-dimensional strain parameters shows that barefoot ran in the force and the vertical direction before and after values were greater than running shoes,barefoot running B2 moment and shoes S2 moment dynamics, according to data before and after, left and right sides and vertical force component of barefoot running less than shoes, barefoot running with the shoes in the vertical direction of the force value maximum, which is running barefoot can reduce the main reason of sports injury; About barefoot running direction before and after shaking is bigger,and and vertical component are less than running shoes; Bare feet run on the front and rear direction is not stable, on the left and right, the more stable running shoes sway; Component in the vertical direction of Fz, barefoot ran a maximum, minimum,and the average value of all want to run to wear shoes, bare feet run less impact on the lower limb, effectively reduce the incidence of sports injury. 3). EMG tests results:barefoot running with the shoes of the average integral gastrocnemius myoelectricity value maximum, the weakest of the tibialis anterior muscle activity,barefoot ran the muscles of the biceps femoris muscle in his calf and amplitude percentage; Run in the middle of the support, barefoot and wearing shoes run average integral electrical values show the calf is the largest, smallest, the biceps femoris muscle in his bare feet run and shares the tibialis anterior muscle biceps muscles amplitude of a smaller percentage and gastrocnemius and vastus lateralis amplitude percentage; In the late support, barefoot running and running shoes are the most active, the tibialis anterior muscle average integral the biceps femoris muscle electromyography minimum value. Running shoes, the tibialis anterior muscle gastrocnemius amplitude percentages than running barefoot.