Seymore Kayla D, Cameron Sarah E, Kaplan Jonathan T, Ramsay John W, Brown Tyler N
Boise State University, Boise, ID, USA.
U.S. Army Natick Soldier Research Development and Engineering Center, Natick, MA, USA.
J Biomech. 2017 Dec 8;65:131-137. doi: 10.1016/j.jbiomech.2017.10.021. Epub 2017 Oct 25.
This study quantified how a dual cognitive task impacts lower limb biomechanics during anticipated and unanticipated single-leg cuts with body borne load. Twenty-four males performed anticipated and unanticipated cuts with and without a dual cognitive task with three load conditions: no load (∼6 kg), medium load (15% of BW), and heavy load (30% of BW). Lower limb biomechanics were submitted to a repeated measures linear mixed model to test the main and interaction effects of load, anticipation, and dual task. With body borne load, participants increased peak stance (PS) hip flexion (p = .004) and hip internal rotation (p = .001) angle, and PS hip flexion (p = .001) and internal rotation (p = .018), and knee flexion (p = .016) and abduction (p = .001) moments. With the dual task, participants decreased PS knee flexion angle (p < .001) and hip flexion moment (p = .027), and increased PS knee external rotation angle (p = .034). During the unanticipated cut, participants increased PS hip (p = .040) and knee flexion angle (p < .001), and decreased PS hip adduction (p = .001), and knee abduction (p = .005) and external rotation (p = .026) moments. Adding body borne load produces lower limb biomechanical adaptations thought to increase risk of musculoskeletal injury, but neither anticipation nor dual task exaggerated those biomechanical adaptations. With a dual task, participants adopted biomechanics known to increase injury risk; whereas, participants used lower limb biomechanics thought to decrease injury risk during unanticipated cuts.
本研究量化了在有身体负重的预期和非预期单腿切入动作中，双重认知任务如何影响下肢生物力学。24名男性在三种负重条件下（无负重（约6千克）、中等负重（体重的15%）和重负重（体重的30%））进行了有和没有双重认知任务的预期和非预期切入动作。下肢生物力学数据采用重复测量线性混合模型，以测试负重、预期和双重任务的主要效应及交互效应。在有身体负重时，参与者增加了站立相（PS）髋关节屈曲角度（p = 0.004）和髋关节内旋角度（p = 0.001），以及PS髋关节屈曲（p = 0.001）和内旋（p = 0.018），还有膝关节屈曲（p = 0.016）和外展力矩（p = 0.001）。在有双重任务时，参与者降低了PS膝关节屈曲角度（p < 0.001）和髋关节屈曲力矩（p = 0.027），并增加了PS膝关节外旋角度（p = 0.034）。在非预期切入动作中，参与者增加了PS髋关节（p = 0.040）和膝关节屈曲角度（p < 0.001），并降低了PS髋关节内收力矩（p = 0.001）、膝关节外展力矩（p = 0.005）和外旋力矩（p = 0.026）。增加身体负重会产生下肢生物力学适应性变化，这被认为会增加肌肉骨骼损伤风险，但预期和双重任务都没有加剧这些生物力学适应性变化。在有双重任务时，参与者采用了已知会增加损伤风险的生物力学方式；而在非预期切入动作中，参与者采用了被认为会降低损伤风险的下肢生物力学方式。
