Department of Biomechanics, Performance Analysis and Strength & Conditioning, Olympic Training and Testing Centre Westphalia, Dortmund, Germany.
Institute of Sport Science, Otto-von-Guericke University, Magdeburg, Germany.
J Athl Train. 2023 Apr 1;58(4):329-337. doi: 10.4085/1062-6050-0010.22.
The Nordic hamstring exercise (NHE) is commonly implemented to selectively improve eccentric knee-flexor strength. However, the standard version of the exercise (leveled shanks, extended hip joint) is too strenuous for most individuals, whose muscle activity rapidly decreases at extended knee angles. Hitherto, a gradual approach to the exercise has been missing. In this exploratory case study, we investigated elite performance to introduce a stepwise progression to the NHE.
To determine the extent to which exercise modifications (shank inclination, additional load, hip flexion) altered NHE mechanics.
One male long jumper (age = 33 years, height = 171 cm, mass = 69 kg) with high-level expertise in the NHE performed 20 exercise variations. The corresponding kinematics, kinetics, and electromyographic activity of the biceps femoris long head (BFlh) and semitendinosus (ST) muscles were evaluated.
Exercise variations demonstrated gradually increased peak moments from 69% (zigzag pose) to 154% (inclined bent single-legged version) versus a standard NHE. Shank inclination and additional load elicited small to moderate effects on peak moments, BFlh, and ST (0.24 ≤ d ≤ 0.72), whereas hip flexion largely affected all tested variables (2.80 ≤ d ≤ 6.66), especially muscle activity (BFlh = -63%; ST = -55% of maximal voluntary isometric contraction).
These insights will help practitioners and scientists design multifaceted stepwise NHE progressions by creating differentiated stimuli that best match the strength capacities of individuals and address their specific needs.
北欧腘绳肌练习（NHE）常用于选择性地提高离心膝关节屈肌力量。然而，对于大多数人来说，标准版本的练习（水平小腿、伸展髋关节）过于费力，因为在伸展的膝关节角度下，他们的肌肉活动会迅速减少。迄今为止，这种练习还没有逐渐的方法。在这项探索性案例研究中，我们研究了精英运动员的表现，以引入 NHE 的逐步进展。
确定练习修改（小腿倾斜度、附加负荷、髋关节屈曲）对 NHE 力学的影响程度。
一名男性跳远运动员（年龄=33 岁，身高=171cm，体重=69kg）具有高水平的 NHE 专业知识，他完成了 20 种运动变化。评估了对应的运动学、动力学和股二头肌长头（BFlh）和半腱肌（ST）肌肉的肌电图活动。
练习变化显示，与标准 NHE 相比，峰值力矩逐渐增加，从 69%（Zigzag 姿势）增加到 154%（倾斜弯曲单腿版本）。小腿倾斜度和附加负荷对峰值力矩、BFlh 和 ST 产生了小到中等的影响（0.24≤d≤0.72），而髋关节屈曲对所有测试变量都有很大的影响（2.80≤d≤6.66），尤其是肌肉活动（BFlh=-63%；ST=-55%最大自主等长收缩）。
这些见解将帮助从业者和科学家通过创造最佳匹配个体力量能力和满足其特定需求的差异化刺激来设计多方面的逐步 NHE 进展。
