The Somatic Connection  |   May 2010
The Somatic Connection
Article Information
The Somatic Connection   |   May 2010
The Somatic Connection
The Journal of the American Osteopathic Association, May 2010, Vol. 110, 271-276. doi:
The Journal of the American Osteopathic Association, May 2010, Vol. 110, 271-276. doi:
“The Somatic Connection” highlights and summarizes important contributions to the growing body of literature on the musculoskeletal system's role in health and disease. This section of JAOA—The Journal of the American Osteopathic Association strives to chronicle the significant increase in published research on manipulative methods and treatments in the United States and the renewed interest in manual medicine internationally, especially in Europe. 
To submit scientific reports for possible inclusion in “The Somatic Connection,” readers are encouraged to contact JAOA Editorial Advisory Board Member Michael A. Seffinger, DO (, or Editorial Board Member Hollis H. King, DO, PhD ( 
Drs Seffinger and King were not involved in the decision to publish these contributions. 
Technology Advances Research on Mechanism of Action for OMT
Clark BC, Walkowski S, Conaster RR, Eland DC, Howell JN. Muscle functional magnetic resonance imaging and acute low back pain: a pilot study to characterize lumbar muscle activity asymmetries and examine the effects of osteopathic manipulative treatment. Osteopath Med Prim Care. 2009;3:7. Accessed May 17, 2010. 
Since its inception a decade ago, muscle functional magnetic resonance imaging (mfMRI) has shown potential for a number of applications in osteopathic manipulative treatment (OMT) research. Unlike surface electromyography, in which myoelectric signal crosstalk makes it difficult to isolate individual muscle activity, mfMRI provides improved clarity of image, spatial resolution for observing individual muscles, and the ability to derive an empirical measure of skeletal muscle proton transverse relaxation time (T2). Muscle activity leads to an increase in T2, which, according to my colleague with expertise in this area, is sensitive to as few as two high-intensity muscle contractions (eg, 80% of maximal strength) or five low-intensity muscle contractions (eg, 25% of maximal strength). The increased rates of cellular energy metabolism increase water content and decrease intracellular pH in the muscle tissue, altering the contrast properties of the images. Researchers are therefore able to noninvasively measure the metabolic and hemodynamic properties of skeletal muscle by observing image contrast differences caused by the muscle activity. 
Researchers at the Ohio University College of Osteopathic Medicine in Athens used this technology in a pilot study that assessed patients with acute low back pain (LBP) before and after OMT. Nine patients with acute LBP were recruited for the study. Acute LBP patients were selected instead of chronic LBP patients because researchers felt that such patients would be more likely to respond to a single OMT session. The researchers also recruited 9 asymptomatic control participants, who were matched for age, sex, and body mass. 
At the initial visit, the acute LBP patients received a physical examination and mfMRI, an OMT session, and a post-treatment mfMRI. Forty-eight hours post-OMT, patients received a second physical examination and a third mfMRI. One LBP patient did not return for the 48-hour follow-up, reducing the number of LBP patients to 8. Control participants received a physical examination and mfMRI in a single visit. 
Researchers used a uniform mfMRI technique for each study participant and obtained images of the lumbar region—including identification of the psoas, quadratus lumborum, iliocostalis/longissimus, and multifidus muscles. Two experienced osteopathic physicians treated the identified somatic dysfunction with a combination of OMT techniques, including articulatory treatment system; counterstrain; high-velocity, low-amplitude; muscle energy; and myofascial release. The LBP patients filled out a 10-point visual analog pain scale before the first mfMRI, immediately after the OMT session, and 48 hours posttreatment. The Oswestry Low Back Pain Disability Index was completed before OMT and at the 48-hour follow-up. 
The mfMRI images were analyzed with the National Institutes of Health's ImageJ software for calculation of T2 (average of the left and right side values for each muscle) and T2 asymmetry (the percent difference in T2 between sides). Results showed there was no statistically significant difference in T2 between LBP patients and control participants. Notably, the quadratus lumborum muscle displayed a statistically significant greater T2 asymmetry in the LBP patients compared to control participants. The psoas muscle also had a large, but not statistically significant, difference in T2 asymmetry between the groups. The mfMRI images included in the article illustrated the dramatic differences of the muscle signal intensity asymmetry in the LBP patients compared to the control group. 
The T2 asymmetry values for the psoas muscle in the LBP patients showed a statistically significant reduction from baseline to immediately after OMT, but values returned to baseline levels 48 hours posttreatment. On visual inspection, the muscle tissue shown in the mfMRI image taken of a LBP patient post-OMT appeared similar to healthy muscle tissue. Using the aforementioned visual analog scale, the LBP patients reported less pain after OMT; this self-reported reduction in pain remained 48 hours posttreatment. Scores from the Oswestry Low Back Pain Disability Index were also lower 48 hours after OMT. 
The researchers speculated the statistically significant improvement in psoas muscle T2 asymmetry after OMT reflected the OMT effect of “balancing” the psoas muscle activity bilaterally—that is, by reducing the activity in the hyperactive side and increasing the activity in the hypoactive side. The interpretation of this finding is somewhat limited by the study's small sample size, however. 
In addition to demonstrating a promising technology for osteopathic research, the authors note other interesting findings worthy of further study. Specifically, 6 of the LBP patients displayed psoas muscle asymmetry values greater than that of the average control participant. In all of these 6 patients, the higher T2 values were associated with the right side muscle and the L4 and L5 vertebrae were rotated left. However, this did not correlate with the location of patients' self-reported pain. 
This study exemplifies how mfMRI is a most promising technology for use in osteopathic research and—at last—offers the ability to investigate more mechanisms of action for OMT. —H.H.K. 
Physiotherapists Surveyed on Adverse Effects of Cervical Manipulation
Sweeney A, Doody C. Manual therapy for cervical spine and reported adverse effects: a survey of Irish manipulative therapists. Man Ther. 2010;15(1):32-36. 
As mentioned in a previous installment of “The Somatic Connection” (J Am Osteopath Assoc. 2009;109[12]:624-625), more research is needed on the safety and efficacy of cervical manipulation. A new study from Ireland adds to the research in this area and highlights international developments in manual medicine and therapy. Physiotherapy researchers in Dublin surveyed members of the Irish organization Chartered Physiotherapists in Manipulative Therapy on their use of manipulation and mobilization for cervical spine disorders and associated adverse events. The 44-item survey was mailed to all 259 members of the organization; 127 members responded for a response rate of 49%. Thirty-four respondents (27%) reported using high velocity thrust (HVT) techniques on any portion of the cervical spine but only 12 (9%) reported using HVT on the upper cervical spine. All respondents reported using non-HVT techniques on the cervical spine. 
It is important to clarify the differences in terminology used by the osteopathic medical profession compared to other manual therapy professions. Osteopathic physicians follow the definitions provided by the Education Council on Osteopathic Principles, which uses “manipulation” to describe all forms of osteopathic manipulative treatment, including thrust and softer techniques ( Most other manual therapists, including physiotherapists, reserve the term “manipulation” to mean high-velocity, low-amplitude thrust technique—or what is described as “HVT” technique in this study. “Mobilization” refers to non-HVT techniques that are usually categorized using four grades, ranging from a vigorous grade one (eg, muscle energy) to grade four, which includes gentle manual contacts (eg, osteopathic medicine in the cranial field). Myofascial release would be categorized as grade two or grade three, depending on whether it was direct or indirect. 
Thirty-three respondents (26%) reported witnessing an adverse event within the past 2 years. Five respondents (4%) reported adverse events associated with the use of HVT, 26 (20%) reported events associated with non-HVT techniques, and 2 (2%) reported events associated with cervical traction. Most adverse events were minor (eg, temporary dizziness, nausea). The most severe events were associated with non-HVT techniques and included one “drop attack” (a sudden loss of muscle tone and a fall), one syncopal event, and one transient ischemic attack 4 days posttreatment. 
Because of the lack of comparable survey instruments, the researchers could not compare the results of this survey with other, similar studies. However, this sample of physiotherapists used HVT on the cervical spine less frequently than indicated in a study by Australian physiotherapists (Man Ther. 2004;9[2]:95-108). Even with the relatively small number of respondents, I am surprised by the number and nature of reported adverse events associated with non-HVT techniques in this study. In the osteopathic literature and in my own experience, there are very few reports of any adverse events from non-HVT techniques. One reason alluded to by the researchers was the likelihood that more severe adverse events were simply not reported. Despite this shortcoming, any data on the association of adverse events with the application of manual medicine and manual therapy are useful for researchers of osteopathic medicine. 
Another interesting finding in this study is the reported assessment for vertebrobasilar insufficiency (VBI). Eighteen (53%) of HVT users and 44 (34%) of non-HVT users reported carrying out full VBI assessment. Of the 33 physiotherapists who reported an adverse event, only 8 (24%) had completed VBI assessment, the results of which were negative. 
According to the authors, the low compliance rate with the use of VBI assessment protocol in this study brings up the question of whether VBI assessment is actually useful in clinical practice. However, in my opinion and experience, a vertebral artery challenge test should be completed and documented before providing osteopathic cervical manipulation; the documentation of this simple vertebral artery challenge test has been deemed sufficient protection in the face of litigation as a result of any adverse event. In the most common method for this challenge test, currently taught in osteopathic medical training, the patient is asked to fully extend the head and then slowly rotate it to the one side then the other while upright, seated, or standing. The observation of any dizziness, nystagmus, nausea, or autonomic nervous system response would be a positive finding and no osteopathic manipulative treatment to the cervical spine should be attempted without further neurologic and vascular assessment (Greenman PE. Principles of Manual Medicine. 2004:198). 
A more controversial element discussed in this survey-based study was whether or not the physiotherapists informed patients that cervical manipulation could result in death. To my knowledge, medical ethics have not come to a consensus on this topic. In this Ireland-based survey, only 6 (18%) of the HTV users and 26 (20%) of the non-HVT users reported informing their patients of the risk of death before providing cervical HVT or non-HVT technique. Fortunately, the reported incidence of death and severe adverse events associated with cervical manipulation is quite rare. However, if there are more reports of such treatment outcomes, expect the adverse events to be a major issue in manual medicine and manual therapy circles. —H.H.K. 
Migraine Headaches Successfully Treated With Myofascial Stretching
Sorrell MR. Myofascial examination leads to diagnosis and successful treatment of migraine headache. J Musculoskel Pain. 2010;18(1):31-37. 
A recent pilot prospective observational study, conducted by a Boston-based neurologist, examined whether palpation of myofascial trigger points could reproduce migraineurs' headache patterns, including aura. Migraine patients underwent physical therapist–supervised muscle stretching (PTS), which significantly reduced the degree of reported headache pain over a 3-month period. 
Forty-nine consecutive migraine patients referred to the author's neurology practice received myofascial examination of the head and neck. The examination consisted of 5 to 15 seconds of firmly (enough to blanch the examiner's nails) pressing each of the following muscle groups: the sternocleidomastoid, trapezius, posterior masseter, temporalis, corrugator supercilious, posterior superior cervical, suboccipitalis, and levator scapulae. If the patient's migraine was reproduced during palpation, he or she was prescribed the aforementioned PTS, which involved stretching along the length of the muscles responsible for reproducing the migraine headache pain pattern. Physical therapists instructed patients to stretch the involved muscles 3 times per day for 3 months. Patients continued their medications unless reductions in their headache pain led to a reduced need for medication. After starting PTS, patients returned for follow-up examinations at 6 weeks and 3 months. 
Based on definitions established by the International Classification of Headache Disorders (ICHD), 23 patients had the diagnosis of migraine without aura (ICHD-II 1.1), 15 had the diagnosis of chronic migraine (ICHD-II 1.5.1), and 11 had the diagnosis of migraine with aura (ICHD-II 1.2). Forty-three (88%) of the 49 patients had their pain reproduced by the myofascial examination (all migraine-without-aura and chronic migraine patients and 5 [45%] of the migraine-with-aura patients). Of those who had their pain reproduced by the myofascial examination, 14 migraine-without-aura, 6 chronic migraine, and 4 migraine-with-aura patients completed PTS, with average reported group improvement being 64%, 72%, and 77%, respectively (mean, 68%; 95% CI, 57%-79%). Nine patients were lost to follow-up and 10 did not undergo PTS. The mean improvement for all non-PTS patients was 5%. 
The author acknowledged the limitations of this pilot study, including small sample size and the fact that all examinations were done by one person. Because of the large treatment effect, however, the author suggested migraine patients whose pain can be replicated with myofascial examination be treated with PTS before administering medication and recommended further study with this protocol. The author observed that while prior studies on the application of physical therapy in the treatment of migraine headaches were unsuccessful, they did not include the PTS technique of stretching the involved muscles along their lengths. 
The author's discussion could be enhanced with information on the success of treating migraines using osteopathic manipulative treatment (OMT). Although osteopathic clinical experience (including my own) abounds with cases of successfully treated headache patients, including migraineurs, there is little research on OMT for such patients. In the past decade, the JAOA has published articles that recommend OMT to manage migraine headache (2007;107[1 suppl 6]:ES10-ES16), headache pain (2005;105[4 suppl 4]:S7-S11), and cervicogenic headache (2000;100[9 suppl 5]:S7-S14), as well as suggest that OMT may lower the cost of care for patients with migraine headaches (2009;109[8]:403-407). 
For those osteopathic physicians who use OMT in the treatment of patients with headache or migraine, this article is most encouraging. Results of this study suggest that myofascial examination may assist in diagnosis and give an indication as to whether or not OMT might be of benefit. Osteopathic physicians may want to consider a home program of muscle stretching in their treatment of patients with headache, similar to the one employed in this study, if they are not already doing so. —H.H.K. 
Manual Therapy, Exercise, and Education for Patients With Osteoporotic Vertebral Fractures
Bennell KL, Matthews B, Greig A, Briggs A, Kelly A, Sherburn M, et al. Effects of an exercise and manual therapy program on physical impairments, function and quality-of-life in people with osteoporotic vertebral fracture: a randomised, single-blind controlled pilot trial. BMC Musculoskelet Disord. 2010;11:36. Accessed May 17, 2010. 
Vertebral fractures are common painful and debilitating sequelae of osteoporosis, which affects millions of patients, primarily women. Osteopathic spinal manipulation using high-velocity, low-amplitude (HVLA) techniques are contraindicated in the presence of vertebral fractures, but other manual treatments with exercise may help return patients to painless and productive function. A team of physical therapist researchers in Australia explored the benefits of manual therapy and exercise for this population in a multi-site randomized single-blinded controlled trial. 
Participants were required to have radiographic evidence of osteoporosis (dual-energy x-ray absorptiometry T score -2.5) and at least one vertebral crush or wedge fracture sustained 3 months to 2 years previously with reduced vertebral height. Other inclusion criteria included primary osteoporosis without signs of osteomalacia or history of corticosteroid-induced osteoporosis and osteoporosis medication (eg, hormone replacement therapy, bisphosphonates) for at least the past 6 months. Women were required to be at least 5 years post-menopause. Exclusion criteria included co-morbidities that would limit exercise ability; radicular signs or symptoms; back pain radiating into a lower limb; previous participation in a formal pain management program for back pain; and physiotherapy for back pain in the past 6 months. 
Twenty participants (17 women, 3 men; age range, 53-90 years) were randomly allocated to an intervention (n=11) or control (n=9) group. The intervention group attended individualized 45-minute manual physical therapy sessions with an experienced physical therapist once a week for 10 weeks and performed daily home exercises with adherence monitored by a self-report diary. The control group received no treatment or exercise prescription. 
At each treatment session, the therapist provided thoracic paraspinal soft tissue massage and spinal posterior-anterior articulatory techniques to decrease back pain, improve posture and thoracic spine mobility, strengthen trunk extensor and lower limb muscles, and improve trunk control. Although therapists were trained on a standardized treatment regimen, they were allowed to modify it based on the participant's tolerance and response. For the first week, participants had postural taping to encourage a retracted scapular and pectoral girdle posture and promote thoracic spine extension. During therapy sessions, the therapists also educated participants on osteoporosis, pain sources, back care, postural awareness, activities to avoid, aims of treatment, and the importance of personal involvement and adherence to the regimen. 
The exercise prescription was also individualized to match each participant's physical capabilities and clinical status. Daily home exercises consisted of addressing posture and range of motion. Strengthening and trunk control exercises were performed three times per week. 
Blinded assessment was conducted at baseline and 11 weeks. The researchers used validated and reliable instruments to assess subjective changes in back pain, physical function, and health-related quality of life as well as objective changes in thoracic kyphosis and back and shoulder muscle endurance and function. The intervention group showed greater reductions in pain at rest and during movement and significantly greater improvements in physical function and muscle endurance. After 10 weeks, 9 (82%) of 11 participants in the intervention group rated their back pain as “much better” compared with only 1 participant (11%) in the control group. No adverse events from the spinal manual therapy were reported. 
Despite the small sample size; lack of placebo groups for manual therapy, exercise, and education; and inability to determine which therapeutic approach was most responsible for the improvements, these results support the benefits of manual therapy combined with exercise and education in the treatment of patients with osteoporotic vertebral fractures. —M.A.S. 
Manual Therapy for Patients With Neck Pain Recommended by Cochrane Systematic Review
Gross A, Miller J, D'Sylva J, Burnie SJ, Goldsmith CH, Graham N, et al. Manipulation or mobilisation for neck pain [review]. Cochrane Database Syst Rev. 2010;(1):CD004249. 
The Cochrane systematic review of randomized clinical trials (RCTs) on spinal manipulation for patients with neck pain is updated every 5 to 7 years. The Cochrane review process entails a rigorous systematic evaluation of the results of published RCTs that are assessed for methodologic quality and bias on a particular intervention in a well-defined patient population. The authors then make clinical practice recommendations based on the strength of the evidence from these RCTs. The 2003 Cochrane review assessed the effectiveness of manual therapy vs exercise vs manual therapy plus exercise and concluded that the most effective management of neck pain was a combination of manual therapy plus exercise. In the updated 2010 review, the authors focused on RCTs that assessed whether manual therapy alone improved pain, function, disability, patient satisfaction, quality of life, and global perceived effect in adults with neck pain of any duration with or without related cephalgia or radiculopathy. 
The 2010 Cochrane review included 27 RCTs (1522 participants) in which high-velocity, low-amplitude (HVLA) manual therapies or non-HVLA manual therapies were compared to no therapy, sham therapy, other treatments and therapies (eg, medication, acupuncture, heat, electrotherapy, soft tissue massage), or each other. The single osteopathic RCT considered by the authors (J Am Osteopathic Assoc. 2005;105[2]:57-68) was excluded from the review because it used multiple modalities instead of a standardized manual treatment approach, which would have enabled comparison with other RCTs that isolated a single manual treatment modality. Thus, the review included manual therapy procedures performed only by chiropractors or physical therapists. 
The authors concluded that for patients with subacute or chronic neck pain, moderate-quality evidence supported that cervical HVLA and non-HVLA manual therapy separately provide pain relief, functional improvement, and patient satisfaction at short- and intermediate-term follow-up; cervical HVLA alone may provide short-term, but not long-term, pain relief; and thoracic HVLA used alone or in combination with electrothermal therapy or individualized physiotherapy may improve pain and function. Non-HVLA and HVLA manual therapy and acupuncture for patients with various durations of neck pain all provided similar pain relief and functional improvement. Low-quality evidence suggested that anterior-posterior or posterior-anterior articulatory cervical spine manual therapy was superior to transverse oscillatory and rotational articulatory procedures. 
Pertinent to osteopathic researchers is the recommendation that more RCTs employ a factorial design to help determine the active agent or agents within a treatment mix. In other words, several treatment groups would be necessary to delineate the effectiveness of a variety of manual therapies, exercises, and other modalities and medications. 
Osteopathic medical care of patients with neck pain comprise a variety of approaches including several types of osteopathic manipulation, both HVLA and non-HVLA, at the discretion of the physician and adjusted to the tolerance and response of the patient. Osteopathic manipulation is applied to somatic dysfunction throughout the body and not localized only to the region of pain. Osteopathic physicians (DOs) who treat patients with neck pain also provide education and prescribe exercise, and medication when indicated. Therefore, a research paradigm to distinguish which DO-provided interventions or combinations of interventions constitute the effective agent or agents would require a factorial design. The research design might include up to eight different groups, hundreds of participants, multiple sites, and, of course, more than a million dollars in funding. The Cochrane review authors also recommended phase II clinical trials, which would help identify the most effective treatment characteristics and dosages. Phase II trials are less expensive and require relatively fewer participants than the factorial design trials and can likely be carried out at many colleges of osteopathic medicine. 
Public concern exists regarding the adverse effects and cost of care of cervical manual therapies. However, in the 27 RCTs, the number of subjects experiencing adverse effects was only reported in 8 trials (29%), 3 of which reported no adverse effects. Five trials reported benign and transient adverse effects (eg, radicular symptoms, head or neck pain, stiffness, minor discomfort, dizziness). Serious adverse events (eg, stroke, serious neurologic deficits), were not reported in any of the trials. No statement regarding the cost of care for manual therapies for patients with neck pain could be made because direct measures of the cost of care were not reported in the RCTs included in this review. 
Regarding the number of manual therapy sessions needed to achieve improved outcomes, low-quality evidence supported that cervical HVLA provided more short-term pain relief than a control therapy for those with acute or chronic neck pain. Low-quality evidence further suggested that 9 or 12 sessions of cervical HVLA were superior to 3 sessions for pain relief at immediate posttreatment follow-up and neck-related disability for chronic cervicogenic headache. Low-quality evidence supported thoracic manipulation as an additional therapy for pain reduction (number of patients needed to treat to have one patient benefit [NNT], 7; 46.6% treatment advantage) and increased function (NNT, 5; 40.6% treatment advantage) in acute pain and favored a single session of thoracic manipulation for immediate pain reduction compared to placebo for chronic neck pain (NNT, 5; 29% treatment advantage). Thus, patients with neck pain can benefit from thoracic manipulation without cervical manipulation. None of the studies investigated treating the lumbar spine, sacrum, pelvis, costal cage, or shoulder girdle for patients with neck pain as DOs who use OMT often do. 
The authors admitted that overall methodologic quality of the RCTs needed improvement. In addition, many potential biases were found in the studies. As a result, optimal techniques and doses are unresolved, and the implications of the review and clinical practice recommendations on the use of osteopathic manipulative treatment (OMT) for patients with neck pain are as yet to be determined. It is imperative that osteopathic researchers investigate the efficacy and effectiveness of OMT for patients with neck pain lest the guidelines established for all clinicians, including DOs, will be based on the results of systematic reviews that evaluate manual therapies as performed by chiropractors or physical therapists. —M.A.S. 
Cranial Rhythmic Impulse Associated With Excessive Crying in Infants
Kotzampaltiris PV, Chou KJ, Wall SP, Crain EF. The cranial rhythmic impulse and excessive crying of infancy. J Altern Complement Med. 2009;15(4):341-345. 
In 1961, JAOA—The Journal of the American Osteopathic Association first reported to the world that there was a palpable rhythmic motion of the parietal bones related to illness. (1961;60[12]:988-993). The researchers investigating this phenomenon coined the term cranial rhythmic impulse (CRI) in that landmark article. Fifty years later, an interprofessional team of DOs, MDs, and PhDs affiliated with the Albert Einstein College of Medicine investigated the relationship between the CRI and excessive crying in infants. 
The article states that excessive crying is a common problem of unknown etiology occurring in 5% to 40% of infants with peak incidence at age 6 weeks. As proposed in the study, the CRI in infants may be related to cranial somatic dysfunction from the forces of labor and delivery on the infant cranium. However, this hypothesis was not explored in their study. Instead, two pediatric DOs recorded the CRI at birth, one of whom recorded the CRI at 2 weeks, in 155 full-term infants in the well-baby nursery of a public hospital in the Bronx, a neighborhood in New York, New York. At 6 weeks, an investigator blinded to the CRI and birth data contacted the primary caretaker over the telephone to assess infant crying based on the modified Ames Cry Score, level of maternal stress, use of home or cultural remedies, and infant diet. 
Sixteen infants had missing data in their records, leaving 139 records for analysis. Fifty-eight infants (41.7%) had excessive crying, which was associated with an abnormal CRI at 2 weeks (P <.001) but not with the CRI at birth (P=.23). Infants with an abnormal CRI at 2 weeks were 6.8 times (95% confidence interval, 2.2-20.6) more likely to develop excessive crying than infants with a normal CRI. There were no confounders to this relationship, including type of delivery, cranial bone molding, type of feeding, ethnicity, gender, birth weight, or maternal age. Infant diet was independently associated with excessive crying. 
Interestingly, interrater agreement for CRI measurement was 0.70 using the κ statistic, revealing a moderate to excellent score for palpatory diagnostic tests. Some reasons for this agreement may be that both DOs were taught how to palpate the CRI in osteopathic medical school, measured the CRI at the cranium only, and determined whether the rate fell within a range using the literature as standard of reference. Thus, they only needed to count the rate of fluctuations in parietal bone movement per minute and state whether it fell within the normal range (10-14 cycles per minute). Additionally, if the palpable motion of the left and right side of the cranium were determined to be asymmetrical, the examiners considered the CRI abnormal. 
The CRI at 2 weeks was 93.1% sensitive and 33.3% specific for excessive crying at 6 weeks. The CRI test will therefore likely have few false negatives but many false positives. Based on these findings, the CRI assessment at 2 weeks is a good predictor for no excessive crying if it is negative, but is not a good screening test to predict its occurrence if positive. 
The authors acknowledged that the modified Ames Cry Score, which consisted of only three questions, each scored 0 to 3, concerning the frequency, average duration, and maximum duration of the infant's cry during the past week, is subject to recall bias, may overestimate prevalence, and may not be the most accurate means of assessing degree of infant crying. 
Overall, the study was well powered and statistically rigorous and demonstrated that an abnormal CRI rate at age 2 weeks may be associated with excessive crying at age 6 weeks. As suggested by the authors, a randomized clinical trial is needed next to assess whether cranial manipulation reduces excessive crying in infants who have abnormal CRI at age 2 weeks. —M.A.S.