Relationship Between Running Economy and Kinematic Parameters in Long-Distance Runners.

Pizzuto, F, Fonseca de Oliveira, C, Amorim Soares, TS, Rago, V, Silva, G, and Oliveira, J. Relationship between running economy and kinematic parameters in long-distance runners. J Strength Cond Res 33(7): 1921-1928, 2019-The purpose of this study was to explore the relationship between running economy (RE) and sagittal, frontal, and transverse plane kinematic parameters in long-distance runners. A secondary purpose was to identify the kinematic predictors of RE during running at the lowest RE value, representing an individual's most efficient running intensity. Twenty recreational long-distance runners ran 3 submaximal stages on a treadmill (65, 75, and 85% of velocity at maximum oxygen consumption). Respiratory data were collected using a portable gas analysis system. Kinematics were gathered using passive retroreflective markers and 8 high-resolution infrared cameras to collect the respective trajectories. Hip, knee, and ankle angles at foot strike and stance phase, as well as spatio-temporal parameters were calculated during each gait cycle. Knee flexion/extension range of motion (ROM), knee ab/adduction ROM, and hip ab/adduction ROM during the stance phase of the gait cycle showed positive moderate to large correlations with RE (r ± 90% confidence intervals = 0.51 ± 0.29; 0.49 ± 0.30; 0.53 ± 0.28, respectively). Knee and hip ab/adduction ROMs during the stance phase are predictors of RE, accounting for 44% of RE variance. Therefore, sagittal and frontal plane kinematics affect RE-inducing alterations in running performance. Coaches, athletic trainers, and anyone involved in running training prescription should consider a relationship between these parameters to ensure optimal technique and, consequently, to improve RE in recreational long-distance runners.

Acute kinematics changes in marathon runners using different footwear.

The effects of running with or without shoes on injury prevention have been extensively studied, and several investigations have assessed biomechanical differences between them. However, findings are not consensual and further insights on biomechanical load associated with differently shod or barefoot conditions may be needed. This study aimed to observe if habitually shod marathon runners show acute alterations when running barefoot or with minimalist shoes, and to determine whether the running kinematical adaptations of wearing minimalist shoes were similar to barefoot running. Twelve male marathon runners ran on the treadmill at their average marathon pace in different footwear conditions: habitual running shoes, minimalist shoes, and barefoot. High-resolution infrared cameras and visual 3D software were used to assess kinematic data. The following parameters were studied: foot strike angle, cycle time, stance time, normalized stride length, hip, knee, and ankle angular position at initial contact, and their respective range-of-motion (ROM) during stance phase. Contrary to the expectations, it was found that highly trained habitually shod elite marathon runners changed their lower limb kinematic pattern both when running barefoot or wearing minimalist shoes. Minimalist shoes showed a trend towards intermediate biomechanical effects between running with and without shoes.