Graduate Program in Rehabilitation and Functional Performance, Ribeirão Preto Medical School, University of São Paulo, Brazil; Biomechanics and Motor Control Laboratory, School of Physical Education and Sport of Ribeirão Preto, University of São Paulo, Brazil.
Center of Physical Education and Sports, Department of Sports, Federal University of Espírito Santo, Brazil.
Gait Posture. 2019 Sep;73:202-208. doi: 10.1016/j.gaitpost.2019.07.306. Epub 2019 Jul 23.
Asymmetrical load-carrying while walking requires modifications in joint forces to compensate the extra mass and ensure body stability, particularly when the environment is uneven, such as with a curb. Carrying a bag with one hand (dominant or non-dominant) may constrain the movement of the arm, altering the interlimb coordination of the upper limbs. Prior studies did not show changes in interlimb coordination when a light load was attached to the wrist, but the use of a bag to carry the load can be potentially disturbing since exaggerated movements of the bags may compromise balance. In this case, changes in interlimb coordination would be expected to minimize bag movements. However, it is not clear if these changes in interlimb coordination would be sufficient to affect the curb negotiation task.
We investigated the effect of asymmetric load-carrying using different bag types with the dominant and non-dominant hands on upper limb coordination and walking adaptations in a curb negotiation task in young adults.
Seventeen young adults walked and stepped down a curb while carrying a bag with 7% of their body mass. The experimental conditions were to walk without the bag, carrying the bag (with and without strap) using the dominant and non-dominant hand.
Carrying the bag reduced the anti-phase pattern and increased the right or left shoulder phases, depending on the side used to carry the bag. It means that the limb that carried the load almost did not move while stepping down the curb. Load transportation did not influence foot-curb negotiation variables.
Our study indicates that a mild load and the bag influenced the interlimb coordination of the upper limbs. Despite that, young adults compensated for the disturbance caused by the load carriage and did not compromise the curb negotiation task.
在行走时承受不对称的负载需要对关节力进行修改以补偿额外的质量并确保身体稳定，尤其是当环境不均匀时，例如在路缘石上。用一只手（优势或非优势手）携带袋子可能会限制手臂的运动，改变上肢的肢体间协调。先前的研究表明，当在手腕上附加轻负载时，肢体间协调没有变化，但是使用袋子来携带负载可能会受到干扰，因为袋子的夸张运动可能会影响平衡。在这种情况下，预计肢体间协调的变化将最小化袋子的运动。但是，尚不清楚这些肢体间协调的变化是否足以影响路缘石协商任务。
我们研究了使用不同类型的袋子（优势手和非优势手）不对称地携带负载对上肢协调的影响，以及在年轻人的路缘石协商任务中行走适应的影响。
17 名年轻人在携带 7％体重的袋子的情况下行走并走下路缘石。实验条件是不携带袋子，用优势手和非优势手携带袋子（有和没有肩带）。
携带袋子减少了反相模式，并增加了右肩或左肩相位，这取决于用来携带袋子的一侧。这意味着承载负载的肢体在走下路缘石时几乎没有移动。负载运输没有影响脚-路缘石协商变量。
我们的研究表明，轻度负载和袋子会影响上肢的肢体间协调。尽管如此，年轻人还是补偿了负载运输引起的干扰，并且没有影响路缘石协商任务。
