Longus colli postural function on neck curve
Longus colli has a postural function on cervical curvature
From: Surgical and Radiological Anatomy. 1994;16(4):367-71
To determine the postural role of longus colli and dorsal neck muscles, we have studied the relationship between their cross sectional areas related to their force of contraction and the lordosis and the length of the neck. This study was carried out in 36 healthy subjects. Muscle cross-sectional areas were measured by computerized tomography. The index of lordosis and the length of the neck were measured on an X-ray profile. The cross sectional area of longus colli was correlated to the lordosis index whereas all the other parameters were not correlated. The authors conclude that longus colli counteracts the lordosis increment related to the weight of the head and to the contraction of the dorsal neck muscles. Postural functions of longus colli and postcervical muscles are complementary. They form a sleeve which encloses and stabilizes the neck in all positions of the head.
The longus colli maintains anterior stability of the neck as a whole and for each individual motion segment. This is the only muscle that sits in front of the spinal column and has attachments confined to the vertebrae.
The longus colli isotonically assists the SCM in neck flexion by stabilizing the vertebral column. It prevents an increase in the cervical lordosis with bilateral SCM contractions and stabilizes the neck in unilateral SCM contraction in neck rotation. The longus colli muscle has a similar stabilizing effect on the scalene neck muscles.
An increase in the cervical lordosis causes the longus colli muscles to lengthen while the neck extensors (scalenes, levator scapulae and upper trapezius) shorten. This is commonly noted clinically with tight neck extensors and scalenes along with weak neck flexors.
While specific craniocervical exercises are indicated for longus colli dysfunction, due to inhibition and chronic lengthening weakness, direct manual pressure into the belly of the longus colli along with perpendicular strumming can help increase play (movement) and tone (hardness). I have found the combination of exercise and direct muscle therapy to reduce longus colli dysfunction and increase neck pain relief.
Comment by Administrator — June 2, 2008 @ 5:17 am