Fice Jason B, Siegmund Gunter P, Blouin Jean-Sébastien
School of Kinesiology, University of British Columbia, Vancouver, BC, Canada.
Ann Biomed Eng. 2014 Sep;42(9):1846-52. doi: 10.1007/s10439-014-1046-0. Epub 2014 Jun 4.
We measured maximum isometric neck strength under combinations of flexion/extension, lateral bending and axial rotation to determine whether neck strength in three dimensions (3D) can be predicted from principal axes strength. This would allow biomechanical modelers to validate their neck models across many directions using only principal axis strength data. Maximum isometric neck moments were measured in 9 male volunteers (29±9 years) for 17 directions. The 3D moments were normalized by the principal axis moments, and compared to unity for all directions tested. Finally, each subject's maximum principal axis moments were used to predict their resultant moment in the off-axis directions. Maximum moments were 30±6 N m in flexion, 32±9 N m in lateral bending, 51±11 N m in extension, and 13±5 N m in axial rotation. The normalized 3D moments were not significantly different from unity (95% confidence interval contained one), except for three directions that combined ipsilateral axial rotation and lateral bending; in these directions the normalized moments exceeded one. Predicted resultant moments compared well to the actual measured values (r2=0.88). Despite exceeding unity, the normalized moments were consistent across subjects to allow prediction of maximum 3D neck strength using principal axes neck strength.
我们在屈曲/伸展、侧弯和轴向旋转的组合情况下测量了最大等长颈部力量，以确定三维（3D）颈部力量是否可以从主轴力量预测得出。这将使生物力学建模人员仅使用主轴力量数据就能在多个方向上验证他们的颈部模型。在9名男性志愿者（29±9岁）中测量了17个方向的最大等长颈部力矩。将3D力矩通过主轴力矩进行归一化，并与所有测试方向的单位值进行比较。最后，使用每个受试者的最大主轴力矩来预测其在非轴向上的合成力矩。屈曲时的最大力矩为30±6 N·m，侧弯时为32±9 N·m，伸展时为51±11 N·m，轴向旋转时为13±5 N·m。除了三个将同侧轴向旋转和侧弯相结合的方向外，归一化的3D力矩与单位值无显著差异（95%置信区间包含1）；在这些方向上，归一化力矩超过了1。预测的合成力矩与实际测量值相比良好（r2 = 0.88）。尽管超过了单位值，但归一化力矩在受试者之间是一致的，从而可以使用主轴颈部力量来预测最大3D颈部力量。
