Acta of bioengineering and biomechanics最新文献

Purpose: The aim of this research is to study the trend of pedestrian lower extremity injuries during vehicle-pedestrian collisions.

Methods: In this study, pedestrian's age, collision angle and pedestrian's position are considered influencing factors. Nine experiments using a novel lower extremity mechanical model are designed with the orthogonal experiment method.

Results: Under the same collision angle, collisions in the left and right positions caused more serious tibia injuries than the middle position. As for the collision angle, the tibial injury at +45° is more significant than the tibial injury at -45°, and the injury of oblique collisions is slightly greater than that at 0°. Moreover, tibial injury is more sensitive to research variables than femoral injury. When the collision angle and position are changed, the difference ratio of tibia stress is by 483.2% higher than that of femur stress. The axial force and bending moment of the quadriceps tendon in the left-position collision reach peak values, which are 3.83 kN and 165.98 Nm, respectively. The peak quadriceps tendon axial force is captured with the collision angle of -45°, and the peak quadriceps tendon bending moment is obtained with a collision angle of +45°.

Conclusions: The effects of differences in impact position and angle on lower extremity injury in the elderly were analyzed, and the results of this study can be used as a reference for research on lower extremity protection.

Performing effective actions requires the basketball player to balance factors such as motor variability, error minimalization and a complex sequence of coordination to determine the best action.

Purpose: The aim of the study was to differentiate the strength of the muscles of the index and middle fingers when performing a basketball shot.

Materials and methods: Study group consisted of 122 male college basketball league students. The study included psychophysiological tests to determine indices of individual and typological characterictics s of higher nervous activity, proprioceptive sensitivity tests of the fingers of the leading hand and field tests to assess participants' shooting skills. The touch-based finger pressure sensing system measured the different levels of pressure exerted by the participants' main index and middle finger during grasping.

Results: For both the middle and index finger, the highest correlation with shot efficiency was found for a 120 g load g (p < 0.01 for 2PS; 2PS40 suc; FT; 3PSO and 3.5 mS). Furthermore, high reproducibility of proprioceptive sensitivity of the index and middle finger of the leading hand was found in basketball players.

Conclusions: The research indicates that it is possible to organize compensatory behavior between joints on the basis of proprioception, with the last compensatory movements of the kinematic chain being performed by the fingers of the hand. The demonstrated high proprioceptive sensitivity of the index and middle finger of the leading hand in basketball players at a weekly interval may indicate ability to maintain high repeatability of movements controlled by these fingers.

Lower extremity injuries in AIS2+ were the most costly injuries through the statistic analysis of traffic accidents. This study aimed to investigate the response characteristics of the lower limb with different contact stiffness, in which knee cushion and foot cushion were applied. First, a model with a human body and a car was established, and the muscle function was activated in lower extremity of human model. Second, the deceleration pulse with a peak of 186 m/s2 was applied to the car to simulate the frontal crash. Then, four sets of simulations with different contact stiffness are conducted to obtain the lower limb responses. Results indicate that the maximum loading of the left and right legs during the impact wes 1.29 and 1.22 kN, respectively. Meanwhile, the maximum moment were 28.82 and 52.17 Nm, respectively. The maximum stress of lower extremity was 87.35 MPa, and the maximum tibia index was 0.230. It was demonstrated that the injury risk of the femur in the groups with equipment of knee cushion and foot cushion was low, but the injury risk of the tibia increased at the same time. This study could provide a reference to the study of lower limb injury in a frontal impact.