Brown Tyler N, O'Donovan Meghan, Hasselquist Leif, Corner Brian, Schiffman Jeffrey M
Oak Ridge Institute for Science and Education (ORISE), Belcamp, MD, USA; U.S. Army Natick Soldier Research, Development and Engineering Center, Natick, MA, USA.
U.S. Army Natick Soldier Research, Development and Engineering Center, Natick, MA, USA.
J Biomech. 2014 Nov 7;47(14):3494-501. doi: 10.1016/j.jbiomech.2014.09.002. Epub 2014 Sep 16.
This study quantified how body borne load impacts hip and knee biomechanics during anticipated and unanticipated single-leg cutting maneuvers. Fifteen male military personnel performed a series of single-leg cutting maneuvers with three different load configurations (light, ~6 kg, medium, ~20 kg, and heavy, ~40 kg). Subject-based means of the specific lower limb biomechanical variables were submitted to repeated measures ANOVA to test the main and interaction effects of body borne load and movement type. With body borne load, stance time (P<0.001) increased, while larger hip (P=0.027) and knee flexion (P=0.004), and hip adduction (P<0.001) moments, and decreased hip (P=0.002) and knee flexion (P<0.001), and hip adduction (P=0.003) postures were evident. Further, the hip (P<0.001) and ankle (P=0.024) increased energy absorption, while the knee (P=0.020) increased energy generation with body borne load. During the unanticipated maneuvers, the hip (P=0.009) and knee (P=0.032) increased energy generation, and peak hip flexion moment (P=0.002) increased relative to the anticipated movements. With the body borne load, participants adopted biomechanical patterns that decreased their locomotive ability including larger moments and reduced flexion postures of the lower limb. During the single-leg cut, participants used greater energy absorption from the large, proximal muscles of the hip and greater energy generation from the knee with the addition of load. Participant's performance when carrying a range of loads was not compromised by anticipation, as they did not exhibit the hip and knee kinetic and kinematic adaptations previously demonstrated when reacting to an unplanned stimulus.
本研究量化了在预期和意外的单腿切入动作中，身体负重如何影响髋部和膝部的生物力学。15名男性军事人员进行了一系列单腿切入动作，采用三种不同的负荷配置（轻，约6千克；中，约20千克；重，约40千克）。对基于个体的特定下肢生物力学变量的均值进行重复测量方差分析，以测试身体负重和运动类型的主效应和交互效应。随着身体负重，站立时间（P<0.001）增加，而髋部（P=0.027）和膝部屈曲（P=0.004）以及髋部内收（P<0.001）力矩增大，髋部（P=0.002）和膝部屈曲（P<0.001）以及髋部内收（P=0.003）姿势减小。此外，随着身体负重，髋部（P<0.001）和踝部（P=0.024）的能量吸收增加，而膝部（P=0.020）的能量产生增加。在意外动作中，相对于预期动作，髋部（P=0.009）和膝部（P=0.032）的能量产生增加，髋部最大屈曲力矩（P=0.002）增加。随着身体负重，参与者采用了降低其运动能力的生物力学模式，包括更大的力矩和下肢屈曲姿势减小。在单腿切入时，参与者随着负荷增加，从髋部的大型近端肌肉吸收了更多能量，并且从膝部产生了更多能量。参与者在携带一系列负荷时的表现并未因预期而受到影响，因为他们没有表现出之前在对意外刺激做出反应时所展示的髋部和膝部的动力学和运动学适应性。
