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BACKGROUND: Foot strike patterns in adults during running have always been the focus of worldwide research, and the strike patterns of children are also something that cannot be ignored. OBJECTIVE: Using biomechanical methods to explore the differences in kinematics and kinetics of children in different strike patterns during the running process, and to provide a scientific basis for children’s correct way of running. METHODS: Seventy-four children were randomly selected from a public kindergarten in Haidian District, Beijing, and were divided into 3-year-old group, 4-year-old group and 5-year-old group. The kinematics and kinetics data of enrolled children in different strike patterns during running were acquired simultaneously using the BTS infrared motion capture system, the Kistler three-dimensional force table and the VIXTA video analysis system. The muscle strength index of the lower limbs was calculated using the Anybody 5.2 simulation modeling software. Before participation in the trial, children’s parents were fully informed of study protocol and signed the informed consent form. The trial protocol met the relevant ethical requirements of Beijing Normal University. RESULTS AND CONCLUSION: (1) In the 3-year-old group, the proportion of mid foot strike (MFS) was the highest, and the proportion of fore foot strike (FFS) was the lowest. In the 5-year-old group, the proportion of MFS was the lowest, and the proportion of FFS was the highest. The rear foot strike (RFS) extension time was longer than that of FFS (P < 0.01) and MFS (P < 0.05). (2) At the moment of landing, the flexion angle of FFS was greater than that of RFS (P < 0.01) and MFS (P < 0.05), and the flexion angle of MFS was greater than that of RFS (P < 0.05). The hip adduction-abduction angle of RFS was greater than that of FFS (P < 0.01) and MFS (P < 0.05). The maximum hip abduction angle of RFS was greater than that of FFS (P < 0.01) and MFS (P < 0.01). The amount of joint changes in the RFS hip adduction and abduction was greater than that of FFS (P < 0.01) and MFS (P < 0.05). The minimum flexion and extension of RFS was greater than that of FFS (P < 0.05). The maximal hip adduction-abduction angular velocity of RFS was greater than that of FFS (P < 0.05), and the maximal knee adduction-abduction angular velocity of RFS was greater than that of FFS (P < 0.01) and MFS (P < 0.05). (3) The muscle strength of the short bones of the tibia, the long tibia and the third metatarsal muscle of FFS and MFS was greater than that of RFS (P < 0.05). The bundle muscle strength of the medial femoral muscle, the lateral femoral muscle bundle, the lateral femoral muscle bundle, the medial femoral muscle bundle, the medial femoral muscle bundle, and the medial femoral muscle of RFS were greater than that of FFS (P < 0.01) and MFS (P < 0.05). (4) In the 3-6 years old, children often run in the heel or full-foot landing mode to meet their stability during the running process. As the age increases, the running pattern with the forefoot landing gradually appears. To keep the movement steady, RFS can trigger more hip and knee frontal motions, FFS and MFS can offer more muscle strength on the anterior and posterior sides of the calf, while RFS can offer more muscle strength on the anterior side of the thigh.
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Objective By establishing the intervention mode of 12-week gait retraining (GR) (with the specific aim of changing the habitual running gait), to determine the changes of vertical ground reaction force (vGRF), kinematics and dynamics of hip, knee, ankle joints, as well as stiffness of lower limbs in running before and after GR, and to explore the influence of running posture transformation on impact force and lower limb biomechanics. Methods Vicon motion capture system and Kistler 3D force measurement platform were used to collect the GRF and marker track of 30 runners (15 in experimental group and 15 in control group) before and after GR with the minimalist shoes at a speed of 12 km/h±5%. Results A total of 17 subjects (9 in experimental group and 8 in control group) completed the GR. After GR, the maximum loading rate of both groups decreased significantly, and the maximum loading rate of experimental group was lower than that of control group. The foot strike angle in experimental group decreased significantly after GR, and the plantarflexion angle and hip joint angular extension velocity increased in both groups. The force moment of ankle joint increased in experimental group, and the stiffness of lower limbs was significantly improved in both groups. Conclusions A 12-week GR exercise intervention model was successfully established, with 78% conversion rate (from rearfoot strike to forefoot strike). GR can effectively avoid the peak of impact force, reduce the maximum loading rate, increase the lower limb stiffness, and thus reduce or even avoid the risk of running injury caused by impact force and may provide a possibility for the improvement of running economy.
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Long distance running is a popular sport with a high risk of getting musculoskeletal injuries, which is closely related to running shoes and foot-strike patterns. Biomechanical researches on relationship of running shoes and foot-strike patterns with running injuries were searched on the chain cloud library and Google academic database, and a total of 42 papers published from 1981 to 2016 were reviewed. There is not enough evidence to prove that running shoes have an effective cushioning and motor controlling function as what they claim, while barefoot running as a kind of more natural running pattern should be encouraged. Generally speaking, the forefoot strike has a lower injury risk on the knee, but increases the load on ankle and metatarsal bones. On the contrary, the rear foot strike always has a higher injury risk on the knee while a lower load on ankle and metatarsal bones. Therefore, runners should choose a suitable running method depending on their own conditions. The influence of running method transformation on biomechanical characteristics of lower limbs is not clear, and researches in such area may give more effective suggestions for runners to change their running methods.
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Objective To investigate the influence of barefoot running and shod running with different foot-strike patterns on characteristics of plantar pressures and ground reaction force (GRF).Methods Kistler force plates and Medilogic insole plantar pressure system were used to collect the kinetic data from a total of 12 healthy male volunteers under shod and barefoot conditions with heel strike and forefoot strike at the speed of 3 m/s,including the GRF,the peak impact force,the maximum loading rate,the peak plantar pressure and impulse.Results (1) Shod running with heel strike significantly reduced the maximum loading rate and extended the time to reach the peak impact force.Under forefoot strike pattern,shod running significantly increased the maximum push-off force than barefoot running.(2) More plantar pressure parameters were influenced by the foot-strike patterns as compared to those under the shod conditions,and there was a significant difference in the peak pressure and the time to reach the peak pressure in the mid-foot and heel region between two foot-strike patterns.Conclusions The foot-strike pattern shows a more obvious influence on plantar pressure during jogging than the shod conditions.Shod running with heel strike can reduce the impact load,while barefoot running with forefoot strike can cause an excessive concentration of plantar pressure on the forefoot region,indicating that a suitable pair of sports shoes is needed for both foot-strike patterns to reduce the plantar pressure during jogging.
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Objective To investigate the influence of barefoot running and shod running with different foot-strike patterns on characteristics of plantar pressures. Methods Kistler force plates and Medilogic insole plantar pressure system were used to collect and compare the kinetic data from a total of 12 healthy male volunteers under shod and barefoot conditions with heel-toe run and toe-toe run at the speed of 3 m/s, including the GRF, loading rate, plantar pressure and impulse. Results (1) Shod running with heel-toe strike significantly reduced the maximum loading rate and extended the time to reach the peak of impact force. Under forefoot strike pattern, shod running significantly increased the maximum push-off force than barefoot running. (2) More plantar pressure parameters were influenced by the foot-strike patterns as compared to those under the shod conditions, and there was a significant difference in the peak pressure and the time to reach the peak pressure in the mid-foot and heel region between the two foot-strike patterns. Conclusions The foot-strike pattern shows a more obvious influence on plantar pressure during jogging than the shod conditions. Shod running with heel strike can reduce the impact force, while barefoot running with forefoot strike can cause an excessive concentration of plantar pressure on the forefoot region, which indicates that a suitable pair of sports shoes is needed for both foot-strike patterns to reduce plantar pressure during jogging.
RESUMO
Objective To investigate the influence of barefoot running and shod running with different foot-strike patterns on characteristics of plantar pressures and ground reaction force (GRF).Methods Kistler force plates and Medilogic insole plantar pressure system were used to collect the kinetic data from a total of 12 healthy male volunteers under shod and barefoot conditions with heel strike and forefoot strike at the speed of 3 m/s,including the GRF,the peak impact force,the maximum loading rate,the peak plantar pressure and impulse.Results (1) Shod running with heel strike significantly reduced the maximum loading rate and extended the time to reach the peak impact force.Under forefoot strike pattern,shod running significantly increased the maximum push-off force than barefoot running.(2) More plantar pressure parameters were influenced by the foot-strike patterns as compared to those under the shod conditions,and there was a significant difference in the peak pressure and the time to reach the peak pressure in the mid-foot and heel region between two foot-strike patterns.Conclusions The foot-strike pattern shows a more obvious influence on plantar pressure during jogging than the shod conditions.Shod running with heel strike can reduce the impact load,while barefoot running with forefoot strike can cause an excessive concentration of plantar pressure on the forefoot region,indicating that a suitable pair of sports shoes is needed for both foot-strike patterns to reduce the plantar pressure during jogging.
RESUMO
Objective To investigate the influence of barefoot running and shod running with different foot-strike patterns on characteristics of plantar pressures and ground reaction force (GRF).Methods Kistler force plates and Medilogic insole plantar pressure system were used to collect the kinetic data from a total of 12 healthy male volunteers under shod and barefoot conditions with heel strike and forefoot strike at the speed of 3 m/s,including the GRF,the peak impact force,the maximum loading rate,the peak plantar pressure and impulse.Results (1) Shod running with heel strike significantly reduced the maximum loading rate and extended the time to reach the peak impact force.Under forefoot strike pattern,shod running significantly increased the maximum push-off force than barefoot running.(2) More plantar pressure parameters were influenced by the foot-strike patterns as compared to those under the shod conditions,and there was a significant difference in the peak pressure and the time to reach the peak pressure in the mid-foot and heel region between two foot-strike patterns.Conclusions The foot-strike pattern shows a more obvious influence on plantar pressure during jogging than the shod conditions.Shod running with heel strike can reduce the impact load,while barefoot running with forefoot strike can cause an excessive concentration of plantar pressure on the forefoot region,indicating that a suitable pair of sports shoes is needed for both foot-strike patterns to reduce the plantar pressure during jogging.