Sleutjens J, Voorhout G, Van Der Kolk J H, Wijnberg I D, Back W
Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, The Netherlands.
Equine Vet J Suppl. 2010 Nov(38):425-30. doi: 10.1111/j.2042-3306.2010.00226.x.
In dressage, the head and neck position has become an issue of concern as certain extreme positions may imply a welfare risk for the horse. In man, extension and flexion of the cervical spine cause a decrease and increase in intervertebral foramina dimensions, respectively. However, in horses, the influence of flexion and extension on foramina dimensions and its possible interference with peripheral nerve functioning remains unknown.
To determine the effect of ex vivo flexion and extension on intervertebral foramina dimensions in the equine cervical spine.
Computed tomography was performed on 6 cadaver cervical spines from adult Warmblood horses subjected to euthanasia for reasons unrelated to cervical spine abnormalities, in a neutral position, in 20 and 40° extension, and in 20 and 40° flexion. Multiplanar reconstructions were made to obtain transverse images perpendicular to the long axis of each pair of intervertebral foramina from C2-T1. Intervertebral foramina dimensions were measured in the 5 positions.
Compared to the neutral position, 40° extension caused a decrease in foramina dimensions at segments C4-C5, C5-C6, C6-C7 (P < 0.001) and C7-T1 (P < 0.002); 20° extension caused a decrease in foramina dimensions at segments C5-C6 (P < 0.02), C6-C7 (P < 0.001) and C7-T1 (P < 0.01); 20° flexion caused an increase in foramen length at segment C6-C7 (P < 0.01).
Ex vivo extension of the cervical spine causes a decrease in intervertebral foramina dimensions at segments C4-T1, similar to that found in man.
In vivo extension of the cervical spine could possibly interfere with peripheral nerve functioning at segments C4-T1. This effect may be even more profound in patients with a reduced intervertebral foramina space, for example in the presence of facet joint arthrosis.
在盛装舞步运动中，马的头部和颈部姿势已成为一个备受关注的问题，因为某些极端姿势可能对马的福利构成风险。在人类中，颈椎的伸展和屈曲分别会导致椎间孔尺寸减小和增大。然而，在马身上，屈曲和伸展对椎间孔尺寸的影响及其对周围神经功能的可能干扰仍不清楚。
确定体外屈曲和伸展对马颈椎椎间孔尺寸的影响。
对6具成年温血马的尸体颈椎进行计算机断层扫描，这些马因与颈椎异常无关的原因实施安乐死，扫描时分别处于中立位、伸展20°和40°以及屈曲20°和40°的状态。进行多平面重建以获得垂直于C2 - T1每对椎间孔长轴的横向图像。在这5种姿势下测量椎间孔尺寸。
与中立位相比，伸展40°导致C4 - C5、C5 - C6、C6 - C7节段（P < 0.001）和C7 - T1节段（P < 0.002）的椎间孔尺寸减小；伸展20°导致C5 - C6节段（P < 0.02）、C6 - C7节段（P < 0.001）和C7 - T1节段（P < 0.01）的椎间孔尺寸减小；屈曲20°导致C6 - C7节段的椎间孔长度增加（P < 0.01）。
颈椎的体外伸展导致C4 - T1节段的椎间孔尺寸减小，这与在人类中发现的情况类似。
颈椎的体内伸展可能会干扰C4 - T1节段的周围神经功能。对于椎间孔空间减小的患者，例如存在小关节骨关节炎的患者，这种影响可能更为显著。
