Ad
related to: right rotation of the cervical spine
Search results
Results From The WOW.Com Content Network
However, the cervical spine is comparatively mobile, and some component of this movement is due to flexion and extension of the vertebral column itself. This movement between the atlas and occipital bone is often referred to as the "yes joint", owing to its nature of being able to move the head in an up-and-down fashion.
The atlas is the topmost vertebra and the axis (the vertebra below it) forms the joint connecting the skull and spine. The atlas and axis are specialized to allow a greater range of motion than normal vertebrae. They are responsible for the nodding and rotation movements of the head.
Downward rotation would be prevented by co-contraction of other muscles that elevate the spine, the upper fibers of the trapezius, which is an upward rotator. When the shoulder is fixed, levator scapulae rotates to the same side and flexes the cervical spine laterally.
After a signal reaches the accessory nerve nucleus in the anterior horn of the spinal cord, the signal is conveyed to motor endplates on the muscle fibers located at the clavicle. Acetylcholine (ACH) is released from vesicles and is sent over the synaptic cleft to receptors on the postsynaptic bulb. The ACH causes the resting potential to ...
Principle I: When the spine is in neutral, sidebending to one side will be accompanied by horizontal rotation to the opposite side. [2] This law is observed in type I somatic dysfunction, where more than one vertebra is out of alignment and cannot be returned to neutral by flexion or extension of the vertebrae. The involved group of vertebrae ...
The atlanto-axial joint is a joint between the atlas bone and the axis bone, which are the first and second cervical vertebrae.It is a pivot joint that provides 40 to 70% of axial rotation of the head.
Their combined action is rotation and extension of the vertebral column. These muscles are small and have a poor mechanical advantage for contributing to motion. They include: the three semispinalis muscles, the multifidus muscle, and the rotatores muscles.
They are innervated by the third to the eighth cervical spinal nerves (C3-C8). The anterior and middle scalene muscles lift the first rib and bend the neck to the side they are on. The posterior scalene lifts the second rib and tilts the neck to the same side. The muscles are named from Ancient Greek σκαληνός (skalēnós) 'uneven'.