Friday, September 17, 2010

Neck pain due scapular origin




Various scapular connections:

Following group of muscles are essential for proper shoulder functioning:
1. Scapulo-humeral group (Supra & infraspinatus, Subscapularis)
2. Cervico-scapular group (Levator scapulae, Upper trapezius)
3. Thoraco-scapular group (Ex: Rhonboids, middle trapezius)
4. Other muscle like latissimus dorsi etc

Shoulder is one of the most active joints of human body & upper limb function is heavily dependant on optimal shoulder joint function. However, the shoulder function is in turn heavily dependant on the scapular stability & mobility. Among various attachments of the scapula, scapular position is also dependant on the Cervico-scapular & other muscles described above. Various scapular conjugate movements with shoulder joint function demands heavy stress on all of it’s attachments. Specific shoulder tasks demands specific static & dynamic scapular positions.

Scapular positional faults & shoulder pain:

Rhomboids dominance: This scapula is rotated on the frontal plane downwards (see the figure). This scapular positioning may lead to premature contact of Gt & acromion that can lead to impingement pain. Hence it is clear that scapular position affect shoulder function.

Brian Mulligan: has explained components of specific scapular positional faults associated with painful shoulder conditions. (Ref: 5th edition of his book)

Scapular positional faults & neck pain:

1. Cervico-scapular focus

Our focus in this topic is scapular positioning & it’s effect on neck. Changes in the alignment of either the scapulae or the cervical spine can potentially influence the biomechanics of the other by altering the tension at the cervicoscapular muscles (1).

Altered scapular alignment is proposed to be related to neck dysfunction and pain. Among the recent occupation related hazards extensive computer use amongst office workers has lead to an increase in work-related neck pain. Aberrant activity within the three portions of the trapezius muscle and associated changes in scapular posture have been identified as potential contributing factors (2). During the typing task people with neck pain generate greater activity in the middle trapezius and less activity in the lower trapezius.

Andrade et al (1) compared the active cervical rotation range of motion (ROM) between healthy young subjects with a neutral vertical scapular alignment and subjects with scapular depression. They also examined the influence of modifying the vertical position of the scapulae on active cervical rotation ROM.

Cervical rotation ROM was assessed for two equal groups out of total 58 college age students ware segregated into neutral vertical scapular alignment or depressed scapular alignment. Cervical rotation ROM was assessed either in resting scapular position or neutral vertical scapular position with forearms supported.

Results suggest that in a young healthy population the vertical scapular alignment does not influence cervical rotation ROM. Supporting the upper limbs, however, results in a significant and similar increase in cervical rotation ROM for both groups.

Van Dillen et al (3): examined the effect of elevating the scapulae on symptoms during neck rotation during physical examination. They obtained data in 2 scapulae positions: a patient-preferred scapulae position and a passively elevated scapulae position. They found in patient-preferred positions, 63% of the 46 patients reported an increase in symptoms with neck rotation in at least one direction. But in passively elevated scapulae position significant percentage of patients reported a decrease in symptoms with neck rotation both in left & right direction.

Passive elevation of the scapulae resulted in a decrease in symptoms with right and left neck rotation in the majority of patients. These findings are important because they indicate that neck symptoms can be immediately improved within the context of the examination. Such information potentially can be used to assist in directing intervention (3).

Levator scapulae syndrome: In an anatomic-clinical study involving 22 alive subjects & 30 cadavers, Menachem et al (4) have reported the following features & reason to this syndrome:

a. Pain over the upper medial angle of the scapula almost always (82%) on the side of dominant shoulder radiating to the neck and shoulder but rarely to the arm.
b. Movements that stretched the levator scapulae on the affected side aggravated symptoms.
c. Radiographs and bone scans of the shoulders and cervical spine were negative. However digital thermographic imaging showed increased heat emission from the upper medial angle of the affected shoulder in 60% of the patients.

Possible explanation for this syndrome was found by anatomic dissection of cadavers. Possible causes are
a. Great variability in the insertion of the levator.
b. A bursa was found between the scapula, the serratus, and the levator in more than 50% of the shoulders.

This study suggests that this syndrome, leading to bursitis and pain, may be caused by anatomic variations of the insertion of the levator scapulae and origin of the serratus anterior. This may explain the constant trigger point and crepitation as well as the increased heat emission found on thermography.

2. Thoraco-scapular focus:

Wegner et al (influence of thoraco-scapular muscles on neck pain): Wegner et al in a recently published study utilized sEMG of the three portions of the trapezius in healthy controls (n=20) to a neck pain group with poor scapular posture (n=18) during the performance of a functional typing task. Again they introduced a scapular postural correction strategy to correct scapular orientation in the neck pain group and electromyographic recordings were repeated. Following correction of the scapula, activity recorded by the neck pain group was similar to the control group for the middle and lower portions.

These findings indicate that a scapular postural correction exercise may be effective in altering the distribution of activity in the trapezius to better reflect that displayed by healthy individuals.

3. The fascia focus:

Off late interesting properties of fascia have reveled that fascia is a independent organ with it’s innate contracting capabilities due presence of myofibroblasts. Misalignments in the body compromise the architectural integrity. At the tissue level, fascia shortens and thickens as the body engages in compensatory strategies to maintain itself upright; these changes are known as myofascial contractions.

In physical therapy, there are several methods by which practitioners treat neck dysfunction. According to James et al (5) Rolfing structural integration (RSI) is capable of significantly decreasing pain and increasing AROM in adult subjects, male and female, with complaints of cervical spine dysfunction regardless of age in 10 basic sessions.

To explore the fascia connections of scapula on needs to read the extra-thoracic fascia. This is present else where in this blog.

References:


1. Andrade GT et al; J Orthop Sports Phys Ther. 2008 Nov;38(11):668-73. (Influence of scapular position on cervical rotation range of motion.)
2. Wegner S et al; Man Ther. 2010 Jul 21. (The effect of a scapular postural correction strategy on trapezius activity in patients with neck pain.)

3. Van Dillen LR et al; lin J Pain. 2007 Oct;23(8):641-7. (The immediate effect of passive scapular elevation on symptoms with active neck rotation in patients with neck pain.)

4. Menachem A et al; Bull Hosp Jt Dis. 1993 Spring;53(1):21-4. (Levator scapulae syndrome: an anatomic-clinical study.)
5. James H et al; J Bodyw Mov Ther. 2009 Jul;13(3):229-38. Epub 2008 Sep 13. (Rolfing structural integration treatment of cervical spine dysfunction.)

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