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Forward head posture (FHP) is a deviation from normal head alignment that causes muscle imbalances, and places an abnormal strain on the musculoskeletal system. The individual who presents with forward head posture (FHP) may be inclined to various impairments because of changes in alignment and function. FHP has been implicated in such conditions as chronic neck and upper back pain, (1) impairment of the upper extremities, (2) headaches, (3-5) and sleep apnea. (6) Established literature recognizes a significant relationship between FHP and temporomandibular disorders (TMD). (7-10)
Ideal posture may be defined as a state in which minimum effort is required to maintain a balanced position and in which a minimum amount of stress is applied to each joint. Viewed laterally, normal postural alignment is identified by a straight line of gravity which runs through the external auditory meatus, passes the tip of the acromial process, travels through the lumbar vertebral bodies, and proceeds posterior to the hip joint and anterior to the knee joint axis and lateral malleolus. (11)
In a position of ideal head posture, the center of gravity is placed slightly anterior to the cervical spine. The trapezius, splenius capitus, and semispinalis capitus muscles support the head against gravity. The sternocleidomastoid muscle assists in stabilizing the head. (7) A slight kyphosis is present between the cranium and C1-C2 vertebrae with correct head posture. A 30-35 degree angle of lordosis should exist at the lower cervical spine, and a normal degree of kyphosis exists at the upper thoracic spine. The distance between a plumb line posterior to the thoracic apex and the midcervical region should be 6-8 cm. (11) The shoulders should be in a position posterior to the first rib and retracted from the clavicle. The stern-ocleidomastoid muscles typically demonstrate an angle of 35-60 degrees from origin to insertion. (12) The weight of the arms is distributed among the interscapular and upper shoulder muscles. This ideal state of balance is determined by the bipupilar, otic, and occlusal planes. These three parallel planes uphold a relationship to each other and to the ground in a normal state of posture. They are responsible for equilibrium and positional awareness of the head in space. Mechanoreceptors in the upper cervical spine and mandible provide feedback to ensure that the relationship between the three planes are maintained. (7) Sight, vestibular orientation, head shape and mass, as well as the need to preserve the pharyngeal airway are all factors influencing natural head posture. (6)
FHP implies that there is an excessive anterior displacement of the head relative to a vertical postural line. The sternocleidomastoid muscles present with an angle greater than 60 degrees, and there is a distance greater than 6-8 cm between the thoracic apex and midcervical region. The extension movement of the head is related to the shortening of the posterior cervical muscles, the scalenes, and the sternocleidomastoid muscles, and to the increased elastic tension of the hyoid muscles, and anterior cervical muscles. A forward movement of the shoulder girdle occurs, shifting the weight of the arms to the upper trapezius and levator scapulae muscles. The middle and lower trapezius muscles and the rhomboids lengthen and become weak, while the pectoral muscles tighten. (13) Proprioceptive changes occur and the brain perceives the assumed faulty posture as being correct, Figures 1 and 2.
While some research fails to prove that there is a significant relationship between TMJ and FHP, (14,15) numerous studies suggest that a forward position of the head can affect function of the temporomandibular joint. (8,16) Further studies confirm that the correction of poor posture may help to relieve symptoms associated with temporomandibular disorders (TMD). (17)
In a forward head position, hyperextension of the head or posterior cranial rotation usually occurs. The suboccipital muscles shorten and the submandibular muscles lengthen. The hyoid bone may elevate due to the lengthening of the infrahyoid muscles and tightening of the suprahyoid muscles. A straightening of the cervical spine with decreased lordosis may be seen. The mandible is directed into an elevated and retruded position, decreasing the interocclusal or freeway space. (18-20) When the head is flexed forward from the hyperextended head position, the mandible also shifts forward, making the TMJ susceptible to excessive shuttling back and forth. This can alter joint mechanics and lead to overstretching of the joint capsule, exposing one to reciprocal clicking and mastication dysfunction. (18)
The Occivator (Posteocentric Systems, Mastic Beach, NY) is an exercise device, developed to restore neutral position of the head, neck, and thoracic spine. Its development has been based upon the spinal corkscrew principle, which likens the mechanism of a corkscrew to the components of head, neck, and spinal alignment. Depression of the shoulder component of the corkscrew drives the head component upward, just as depression and retraction of the shoulder girdle complex lengthens the spine and directs the occiput up and into a flexed position over the cervical spine. (21)
The Occivator is designed to facilitate strengthening of the weak phasic muscles and lengthening of the tight postural muscles. This intervention is hypothesized to direct the head forward and up on the neck, in order to correct forward head posture. Dental experts in TMD were consulted during the development of this device to ensure that there was no potential for adverse effects posed on the mandible. Although the chin strap appears to impose a force of retrusion on the mandible, the correction of FHP balances this force by directing the lower jaw down and forward. The net result is a comfortable rest position of both TM joints. This intervention may have future implications for people who suffer from impairments related to forward head posture, particularly patients who have been diagnosed with postural-related TMD. The purpose of this study is to evaluate the effectiveness of the Occivator as a therapeutic intervention for the correction of forward head posture, Figures 3 (A and B).
Material and Methods
Subject Selection
This pretest-posttest control group design study utilized a sample of convenience. Twenty-nine (29) subjects were recruited from the New York Institute of Technology campus in Old Westbury, New York. The mean age of the subjects in the control group was 35.2 and consisted of seven males and eight females. The mean age of the subjects in the experimental group was 31.2 yrs. and consisted of six males and eight females. Subjects were informed that they would be participating in a study involving forward head posture. The Institutional Review Board at the New York Institute of Technology approved this study, and all subjects read and signed an informed consent form prior to participating in the study. Potential subjects were screened by taking their history and answering a questionnaire. Subjects were excluded from this study if:
* Subject was symptomatic or presented with any orthopedic dysfunction;
* Subject had received intervention for forward head posture or cervical thoracic dysfunction;
* Subject had received chiropractic, physical therapy, occupational therapy or osteopathic treatment for forward head posture within the past six months;
* Subject was diagnosed with Down Syndrome, Spina Bifida, or Rheumatoid Arthritis;
* Subject had a pacemaker; or
* Subject was below the age of 18.
In order to participate in the study, subjects needed to present with forward head posture based on a postural assessment utilizing a plumb line. Each subject was instructed to stand so that a plumb line was positioned to run through the acromion process of the shoulder. The subject was asked to look straight ahead while a photograph was taken. A plumb line running posterior to the earlobe indicated whether the patient had forward head posture.
Measurement
FHP was quantified through use of the cervical range of motion (CROM) device (Performance Attainment Associates, Rosenville, NJ) (Figure 4). The CROM does not offer a criterion that determines if a subject has FHP, however it does allow us to make comparative measurements of head position. Head position was determined through use of a horizontal arm and vertebra locator. The horizontal arm was used to determine the distance from the bridge of the nose to the intersection of the vertebra locator. Measurements were taken based on units of 0.5cm. A study by Garrett indicated that the CROM has high intertester reliability (ICC=0.93) for measuring forward head posture. (22)
All measurements were taken by the same tester, pre and post a two-month period. Before beginning this study, the tester received one 15 minute training session on use of the CROM. A single blinded study was employed in order to limit tester bias. In order to accommodate subjects, testing was performed at different location sites. In order to maintain some level of consistency, the site of measurement was the same for each individual subject, both pre and post the eight-week period. The subject was seated upright with thoracic and lumbar spine securely filling the gap, feet positioned flat on the floor and arms resting freely at the subject's sides. The pre and post test measurements of FHP in cm. were then utilized for subsequent data analysis.
Procedure
Subjects were randomly assigned to a control group or an experimental group. The control group did not receive any treatment. The experimental group followed a procedure incorporating four techniques using the Occivator. Experimental subjects met with a co-investigator two times a week for eight weeks. All techniques using the Occivator were administered and supervised by a trained co-investigator of the study. Each co-investigator underwent two one-hour training sessions and was also required to review a CD-ROM tutorial on use of the Occivator. Each subject in the experimental group received manual therapeutic guidance, as needed, to enhance the sensorimotor learning experience. Subjects performed exercises using the Occivator at one consistent location site throughout the treatment period. To make it more convenient for subjects, treatment sessions usually took place at the subject's home. The Occivator was positioned with the superior pulley at a 30 degree angle. The subject was seated six inches away from the wall with a rolled towel placed behind his/her lower back to prevent lumbar kyphosis.
Subjects in the experimental group performed the following protocol:
1. Week #1: Two sessions on the Occivator during which the subject was taught the Basic Stretch. This included instruction in the chin-tuck exercise. As the subject downwardly pulls the rope handles, the occiput is passively flexed. The axis of rotation occurs through the ears. The motion induced during the basic stretch is a forward and up movement of the occiput. The muscles stretched include the occipital extensors, upper trapezius, and the levator scapulae. Once the subject was proficient, he/she performed the Basic Stretch ten times with a ten-second hold (the stretch must be felt in the sub-cranial region and not below). The subject was then instructed to assume this position throughout the day on an hourly basis. Note: The subject's lumbar spine was placed in neutral at all times when using the Occivator.
2. Week #2: Two sessions on the Occivator during which the subject:
a. Performed the Basic Stretch (ten times with a 30 second hold);
b. Performed Neck Retraction. This maneuver began with the Basic Stretch and proceeded with a posterior gliding motion of the lower cervical spine. The retraction element addresses the forward neck. This was held for ten seconds and repeated ten times. The subject was instructed to assume his/her new postural position on an hourly basis throughout the day.
3. Week #3- Two sessions on the Occivator during which the subject:
a. Performed the Basic Stretch as in week #2
b. Performed Neck Retraction as in week #2
c. Performed Thoracic Extension. This application begins with the Basic Stretch and follows through with Neck Retraction. There is an added element of head-neck extension, followed by depression and retraction of the scapula and extension of the thoracic spine. This exercise aims to restore flexibility of the spine and to reinstate balance and trunk support. The muscles active with this exercise include the middle and lower trapezius muscles, rhomboids, and serratus anterior. The muscles that are lengthened include the pectoralis minor and major as well as the scalenes and neck flexors. Manual guidance was provided to the subject, and each exercise was performed ten times and held for ten seconds. As in week #2, the subject was instructed to assume this new position on an hourly basis throughout the day.
4. Week #4- Two sessions on the Occivator as with week #3.
5. Week #5- Two sessions on the Occivator during which the subject:
a. Performed the Basic Stretch as in week #2
b. Performed Neck Retraction as in week #2
c. Performed Thoracic Extension as in week #3
d. Performed Standing Corkscrew technique. This exercise is based upon the spinal corkscrew principle. While the shoulder girdle descends, the occiput is directed up and forward on the neck. The subject stands with his/her pelvis in neutral, and with his/her arms at the level of the hip. The patient simultaneously depresses at the acromioclavicular joint and elevates at the sternoclavicular joint. This was repeated ten times and held for ten seconds. As in week #2, the subject was instructed to assume their new postural position on an hourly basis throughout the day.
6. Week #6, 7, and 8, two sessions as in week #5.
Data Analysis
The change from pretest to posttest in FHP was utilized for data analysis. A one-tailed independent t-test was utilized to determine if there was a significant difference between the experimental and the control group on improvements in FHP. An alpha level of p>.05 was used for all statistical comparisons. All statistical procedures utilized SPSS version 10.0 (SPSS, Chicago, IL).
Results
Tables 1 and 2 represent pre--and posttest measurements of forward head posture and the percentage of change. Table 3 presents the mean and standard deviation of the experimental and control group. There was a significant difference between the experimental group and the control group (p=.02) on improving FHP as demonstrated by the one-tailed independent t-test.
Discussion
The results of this pilot study demonstrate the effectiveness of the Occivator in improving FHP. This can be explained biomechanically, by the passive elongation of the suboccipital muscles, and strengthening of the deep cervical muscles to restore alignment of the head. Significant change in FHP can also be attributed to subjects being more aware of neck posture, having participated in exercises that promote postural awareness. Further studies comparing previously established postural exercises to exercises performed on the Occivator should be pursued.
Since this was a pilot study, our goal was to identify and eliminate sources of error that might compromise data outcome in future trials. In order to improve the reliability and validity of this study, modifications to some of the measuring devices need to be made. There is some deficiency with relying on visual assessment in order to determine forward head posture with use of a plumb line. Viewing the subject at different angles may influence tester assessment. In order for subjects to qualify for the study, a more quantitative criteria should be established. Situations arose in which subjects who had forward shoulders did not technically fit our criteria for having forward head posture, since a plumb line will technically run through the external auditory meatus and through the acromium. In future studies, use of a carpenter's trisquare and goniometer might provide testers with a more quantitative way of verifying measurements of head position and a standard for forward head posture. In a study by Harrison, Greb, and Wojtowicz, (23) the trisquare was used to determine linear measurements of various anatomical landmarks, and a goniometer was used to establish angular measurements in order to determine head and shoulder posture in the sagital plane. Experimenters can further improve consistency by photographing subjects with a tripod preset to a consistent height and angle. Subjects were informed that they would be participating in a study that involved correction of posture. When posing for a photograph, this knowledge may have prompted the subject to assume an unnatural stance.
The study was based on a sample of convenience in which subjects were assigned to groups, rather than randomly selected. Further experiments on efficiency of the Occivator will impose stricter sampling guidelines in order to avoid the risk of exposing this study to sample bias. Pre and post measurements of FHP should be taken at the same location site and on the same day for all subjects, for better standardization.
Conclusion
This pilot study demonstrates that use of the Occivator was effective in improving FHP. Studies with a larger sample size and with greater control over confounding variables should be conducted for further investigation of the Occivator as an intervention for the correction of FHP. Future studies can examine the implications that this device may have on patients suffering from postural-related TMD.
Manuscript received
February 6, 2006; revised manuscript received August 7, 2007; accepted December 11, 2007
References
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(2.) Novak CB, Mackinnon SE: Multilevel nerve compression and muscle imbalance in work-related neuromuscular disorders. Am J Ind Med 2002; 41(5):343-352.
(3.) Placzek JD, Paget B, Roubal P, Jones B, McMichael H, Rozanski E, Gianotto K: The influence of the cervical spine on chronic headache in women: a pilot study. J Manual Manip Ther 1999; 7(1):33-39.
(4.) Watson DH, Trott PH: Cervical headache: an investigation of normal head posture and upper cervical flexor muscle performance. Cephal 1993; 13(4):272-284.
(5.) Marcus D, Mercer S: Musculoskeletal abnormalities in chronic headache: a controlled comparison of headached diagnostic groups. Headache 1999; 39:21-27.
(6.) Ozbek M, Miyamoto K, Lowe A, Fleetham J: Natural head posture, upper airway morphology, and obstructive sleep apnea severity in adults. Eur J Orthod 1998; 20:133-143.
(7.) Rocabado M: Diagnosis and treatment of abnormal craniocervical and craniomandibular mechanics. In: Solberg WK, Clark GT, eds. Abnormal jaw mechanics: diagnosis and treatment. Chicago, IL: Quintessence Publishing, 1984.
(8.) Lee WY, Okeson J, Lindroth J: The relationship between forward head posture and temporomandibular disorders. J Orofac Pain 1995; 9(2): 161-167.
(9.) Evcik D, Aksoy O: Correlation of temporomandibular joint pathologies, neck pain, and postural difference. J Phys Ther Sci 2000; 12:97-100.
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(12.) Dunn JJ, Mannheimer JS: The cervical spine. In: Pertes RA, Gross SG, eds. Clinical management of temporomandibular disorders and orofacial pain. Chicago, IL: Quintessence Publishing, 1995.
(13.) Janda V: Muscles and cervicogenic pain syndromes. In: Grant R, ed. Physical therapy of the cervical and thoracic spine. New York, NY: Churchill Livingstone, 1988.
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(16.) Darling DW, Kraus S, Glasheen-Wray MB: Relationship of head posture and the rest position of the mandible. J Prosthet Dent 1984; 52(1):111-115.
(17.) Wright EF, Domenech MA, Fischer JR: Usefulness of posture training for patients with temporomandibular disorders. J Am Dent Assoc 2000; 131(2):202-210.
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(21.) Makofsky HW: Spinal manual therapy, an introduction to soft tissue mobilization, spinal manipulation, therapeutic and home exercises. New Jersey: Slack Inc., 2003.
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Address for correspondence:
Dr. Catherine Augustine
131 North Suffolk Ave.
Massapequa, NY 11758
E-mail: AugustCM@aol.com
Catherine Augustine, P.T., D.P.T.; Howard W. Makofsky, P.T., D.H.Sc., O.C.S.; Christina Britt, P.T., D.P.T.; Barbara Adomsky, P.T., D.P.T.; Jennifer Matire Deshler, P.T., D.P.T.; Paula Ramirez, P.T., D.P.T.; Peter Douris, P.T., D.P.T., Ed.D.
Dr. Catherine Augustine received her B.A. degree in 2000 from the State University at Albany, New York and a doctorate degree in physical therapy from the New York Institute of Technology in 2005. Dr. Augustine works as a physical therapist at St. Charles Rehabilitation in Pachogue, New York.
Dr. Howard Makofsky received his bachelor's degree in human physiology from McGill University in 1977, a bachelor's degree in physical therapy and a master's degree in health sciences, both from Stony Brook University in 1979 and 1993, respectively. He received a doctorate in health sciences from the University of St. Augustine for Health Sciences in 1999. Dr. Makofsky is an associate professor in the Physical Therapy Department at the New York Institute of Technology and an adjunct professor at the Toura College, School of Health Sciences.
Dr. Christina Britt received her bachelor's degree in health sciences from the University of Miami in 2000 and a D.P.T. from the New York Institute of Technology in 2005. Dr. Britt is a manual physical therapist employed by Physiologic PT in Great Neck, New York and Long Beach Medical Center.
Dr. Barbara Adomsky received her D.P.T. from the New York Institute of Technology in 2005 and received a B.S. in business administration from Rider College in 1988. Currently, she is employed at Long Island Jewish Medical Center where she treats a variety of balance, neurological and orthopedic patients. Dr. Adomsky also works part-time at Orthopedic Care of Long Island and Glen Cove Center for Nursing & Rehabilitation, as well as providing home care services.
Dr. Jennifer Matire Deshler received her bachelor's degree in science in 2003 and a D.P.T. in 2005, both from the New York Institute of Technology. Dr. Deshler has worked in the outpatient department of the St. Charles Hospital for the past two years and is also a contract physical therapist for school aged children for Tender Age PT, Inc.
Dr. Paula C. Ramirez received a D.P.T. degree from New York Institute of Technology in 2005. She continued her education in 2006 studying Differential Diagnosis and Treatment of Hip and Lumbar Spine Pathology at Weill Medical College of Cornell University. Dr. Ramirez has clinical experience at Suffolk Physical Therapy and Northport VA Hospital, Northport, New York.
Dr. Peter Douris received his B.S. degree in physical education from Hunter College in 1979, a master of science degree in physical therapy from Columbia University in 1982, a master of education in movement science in 1989, a doctor of education in movement sciences in 1989, and a doctor of physical therapy degree in 200Z Dr. Douris is an associate professor in the Physical Therapy Department at the New York Institute of Technology.
Table 1
Experimental Group
% Change
Subject Measurement Pre Post Delta [(delta/pre)
(cm) (cm) (cm) * 100]
1 FHP 22.0 21.5 0.5 2.27
2 FHP 19.0 17.5 1.5 7.89
3 FHP 19.0 18.5 0.5 2.63
4 FHP 21.5 21.5 0 0
5 FHP 20.5 17.5 3.0 14.63
6 FHP 20.5 17.5 3.0 14.63
7 FHP 19.0 17.5 1.5 7.89
8 FHP 25.5 25.0 0.5 1.96
9 FHP 18.5 17.0 1.5 8.11
10 FHP 17.5 17.0 0.5 2.86
11 FHP 19.5 19.5 0 0
12 FHP 19.5 18.5 1.0 5.13
13 FHP 19.5 20.0 -0.5 -2.56
14 FHP 20.0 18.0 2.0 10.0
Mean 20.1 1.94 1.07 5.39
SD 14.0 2.29 1.07 5.33
FHP: Forward head posture
SD: Standard deviation
Table 2
Control Group
% Change
Subject Measurement Pre Post Delta [(delta/pre)
(cm) (cm) (cm) * 100]
1 FHP 16.5 17.0 -0.5 -3.03
2 FHP 17.5 18.0 -0.5 -2.86
3 FHP 20.5 18.0 2.5 12.20
4 FHP 20.5 18.5 2.0 9.76
5 FHP 19.0 18.5 0.5 2.63
6 FHP 23.0 23.5 -0.5 -2.17
7 FHP 21.0 21.0 0 0
8 FHP 21.5 21.5 0 0
9 FHP 21.5 21.0 0.5 2.33
10 FHP 23.5 25.0 -1.5 -6.38
11 FHP 19.0 19.0 0 0
12 FHP 22.0 21.5 0.5 2.27
13 FHP 20.5 20.5 0 0
14 FHP 18.5 18.0 0.5 2.70
15 FHP 21.0 21.0 0 0
Mean 20.37 1.95 0.23 1.16
SD 20.13 2.26 0.98 4.71
FHP: Forward head posture
SD: Standard deviation
Table 3
Mean and Standard Deviation Comparison
Between Experimental and Control Groups
No. Mean SD
Control Group 15 0.23 0.98
Experimental Group 14 1.07 1.07
SD: Standard deviation
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