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10 Articles in Volume 9, Issue #8
Adjunctive Psychiatric Pain Management Treatment
Deep Cervical Muscle Dysfunction and Head/Neck/Face Pain–Part 2
Hackett-Hemwall Dextrose Prolotherapy for Unresolved Elbow Pain
Intradermal BTX-A Reduces Frequency and Severity of Pain for MMD
Keeping Prescribers on Board if Certification Becomes Part of REMS
Magneto-Laser Therapy of Pulpitis and Vertebra Column Osteochondrosis
Pain and Self-regulation
Pain Care of Severely Neurally-Compromised Patients
Simultaneous Use of Opioid and Electromagnetic Treatments
The Experience of Pain

Deep Cervical Muscle Dysfunction and Head/Neck/Face Pain–Part 2

Deep cervical flexor strength and endurance training may be useful in the management of symptoms related to mechanical impairment of the neck.

This article is a follow-on to the article by the same title appearing in the January/February 2009 issue.

Neck pain can be a disabling disorder characterized by periods of remission and exacerbation. It is estimated that in any 6-month period, 54% of adults will experience neck pain.1 There is evidence in the modern literature that changes in deep cervical (neck) muscle (longus capitis, rectus capitis anterior, rectus capitis lateralis, and longus colli) function, as measured by EMG, are associated with neck disorders.2 These changes indicate a reorganization of the motor strategy to perform specific tasks such that neck pain is associated with disturbed neural control of the cervical muscles. These impairments in deep cervical muscle function may result in heightened activity of the superficial muscles (e.g., sternocleidomastoids and anterior scalenes) during craniocervical flexion and upper limb movements.1 Although many muscles of the neck contribute to stabilization and protection of the cervical spine, the deep cervical flexors are critical for the control of intervertebral motion and control of the cervical lordosis.3 The importance of training the core stabilizers in the lumbar spine has been accepted for some time,4 but the importance of core stability in the cervical spine is relatively new. As reported in Part I, cervical dysfunction may be seen in up to 70% of the population suffering from any type of recurring headache.5

In recent years, there has been an increase in the investigation of cervical motor impairment associated with headaches. It is known that cervicogenic headache sufferers present with many neuromuscular changes that are different from those suffering from neck pain only.6 In addition, reduced range of motion is a criterion for cervicogenic headache but not for migraine or tension-type headache.7,8,9

Cervicogenic headache sufferers demonstrate deficits when measuring the strength of the deep cervical flexor muscles, while this is not reported in tension-type and migraine headache.6,10,11 The Head Raise Test provides a simple means of identifying such weakness. During this test, the patient raises his/her head from the table, while the clinician closely observes the direction of chin movement. In optimal firing order during head-neck flexion (longus capitus/rectus capitis anterior, longus colli, anterior scalenes, and sternocleidomastoids) the muscles cause the chin to tuck toward the chest during the first two inches of flexion. In forward head posture (FHP), hypertonic sub-occipitals reciprocally weaken the longus capitus and rectus capitis anterior, causing the sternocleidomastoids (SCMs) to fire first. The chin responds by reaching toward the ceiling, rather than tucking toward the chest.12,13 The Craniocervical Flexion Test (CCFT) has been utilized to suggest that impairment in low-load endurance of the deep cervical flexors is found in individuals with cervicogenic as well as chronic tension-type headache.2,6,14

Despite the growing awareness of the importance of deep cervical muscle strength and endurance, practitioners have few avenues available for in-office testing. In addition to the CCFT, another clinical test of the deep cervical flexor muscles was described by Grimmer in 1994.15 This test was based upon an exercise introduced by Trott in 1988 aimed at “…educating anti-gravity function of the cervical short flexor muscle groups…” It is believed that the use of this type of test for deep cervical muscle performance is useful for practitioners in the assessment of deep cervical flexor endurance. Lastly, Olson et al have demonstrated good inter-tester and intra-tester reliability with the Flexor Endurance Test.16 It is a simple means of assessing endurance capacity of the deep cervical flexor muscles and is the clinical test of choice in this study.

With this in mind, the Physical Therapy Department in the School of Health Professions at the New York Institute of Technology, designed a study to determine the effect of PostureJac®, a postural support and exercise jacket, on endurance of the deep cervical flexors.

Figure 1. Demonstration of position of the no-treatment control Figure 2. Demonstration of position of the treatment control Figure 3. Demonstration of position of the experimental subject.

Research Study

Forty-five subjects between the ages of 18 and 40 years in good health were randomly assigned to three groups, consisting of the no-treatment control, the treatment-control, and the experimental (PostureJac) group. The no-treatment control group subjects were placed in the supine position, with hands resting on their abdomen (see Figure 1). The treatment-control group was placed in the supine position, with arms extended and hands holding onto the table for support (see Figure 2). The experimental group was given the PostureJac while in the supine position and engaged the handles in a downward direction (see Figure 3). The outcome measure of deep cervical flexor muscle endurance was based on the results of the Flexor Endurance Test16 and recorded in seconds. The average of four trials for each subject, on different days, was taken as the final measure of deep cervical flexor endurance.

The subjects were asked to raise their heads just enough to allow the tester to slide the widths of the index and middle finger, one on top of the other, under the most posterior aspect of the occiput. The subjects relaxed their heads on the examiner’s fingers. The subjects were instructed to perform a “chin-tuck” and raise the head slightly off the examiner’s fingers. Throughout the test, the examiner moved his/her fingers side to side under the subject’s head in order to provide tactile feedback for proper maintenance of head position.

Timing began when the subject raised his/her head off the examiner’s fingers, and was ended when 1 or more of 4 criteria were met:

  1. the subject experienced pain and was no longer willing to continue;
  2. the subject held the test position, but reaching the end of endurance, was unwilling to continue;
  3. the examiner determined that the subject had lost the chin-tuck position;
  4. the examiner determined that the subject raised his/her head (flexed the neck while still in chin-tuck) such that the tester’s fingers no longer maintained contact.

Time for the test was recorded to the nearest hundredth of a second.

Data Analyses

The average times for each group were calculated using a one-way ANOVA with a Tukey Post Hoc Analysis of the no-treatment control, treatment-control, and experimental groups.


The experimental (PostureJac) group was shown to have the longest average time during the Flexor Endurance Test (i.e., 23.88 seconds). The no-treatment control group averaged 15.93 seconds and the treatment-control (table stabilization) group averaged 16.86 seconds. There was a statistically significant difference demonstrated between the no-treatment control group and the PostureJac group (p =.001) and between the treatment-control and the PostureJac group (p = .004). However, there was no statistically significant difference between the no-treatment and treatment-control groups (p = .895). These data demonstrate that the PostureJac influence was statistically significant in achieving deep neck flexor activation and sustaining chin-tuck stabilization when compared to the no-treatment control and the treatment-control groups.

Clinical Implications

Based upon these data, the PostureJac, a postural support and exercise jacket, (SomatoCentric Systems, Inc., Toronto, Ontario, Canada, www.posturejac.com) is effective in the immediate enhancement of deep neck flexor muscle endurance. It remains to be seen whether long-term improvement in endurance also occurs, but it is likely that with training this would be the case. It is theorized that the PostureJac enhances activation of the deep cervical flexors by providing optimal mechanical stability to the cervical spine and scapulothoracic region. Consequently, the deep neck flexors are better able to flex the head on a stable, as compared to a mobile, ‘platform’ and demonstrate improved strength, power, and endurance as a result.

The obvious implication of this finding is that the PostureJac may prove useful in the treatment of patients with chronic neck pain,1,3 as well as cervicogenic and tension-type headaches.2,6,14 Improving deep cervical flexor muscle endurance and therefore enhancing core stability to the neck may also have therapeutic implications for patients suffering from post-concussional headache,17 respiratory dysfunction,18 and conditions associated with forward head posture including: temporomandibular disorders,19,20 fibromyalgia,21 osteoporosis,22 migraine headaches,23 and carpal tunnel syndrome.24

Table 1. Recorded average time for each of the 3 groups


In this research study, the PostureJac was superior to the no-treatment control (no stabilization) and the treatment-control (table stabilization), in increasing endurance of the deep cervical flexors. Because deep cervical flexor strength and endurance is necessary for normal cervical spine physiology, PostureJac training may be useful in the management of symptoms related to mechanical impairment of the neck.

Last updated on: January 28, 2012
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