Total head excursion and resting head posture: normal and patient comparisons

Machine learning models for classifying non-specific neck pain using craniocervical posture and movement

OBJECTIVE

Physical therapists and clinicians commonly confirm craniocervical posture (CCP), cervical retraction, and craniocervical flexion as screening tests because they contribute to non-specific neck pain (NSNP). We compared the predictive performance of statistical machine learning (ML) models for classifying individuals with and without NSNP using datasets containing CCP and cervical kinematics during pro- and retraction (CKdPR).

DESIGN

Exploratory, cross-sectional design.

SETTING AND PARTICIPANTS

In total, 773 public service office workers (PSOWs) were screened for eligibility (NSNP, 441; without NSNP, 332).

METHODS

We set up five datasets (CCP, cervical kinematics during the protraction, cervical kinematics during the retraction, CKdPR and combination of the CCP and CKdPR). Four ML algorithms-random forest, logistic regression, Extreme Gradient boosting, and support vector machine-were trained.

MAIN OUTCOME MEASURES

Model performance were assessed using area under the curve (AUC), accuracy, precision, recall and F1-score. To interpret the predictions, we used Feature permutation importance and SHapley Additive explanation values.

RESULTS

The random forest model in the CKdPR dataset classified PSOWs with and without NSNP and achieved the best AUC among the five datasets using the test data (AUC, 0.892 [good]; F1, 0.832). The random forest model in the CCP dataset had the worst AUC among the five datasets using the test data [AUC, 0.738 (fair); F1, 0.715].

CONCLUSION

ML performance was higher for the CKdPR dataset than for the CCP dataset, suggesting that ML algorithms are more suitable than classical statistical methods for developing robust models for classifying PSOWs with and without NSNP.

Reliability and measurement properties of upper cervical flexion-extension range of motion testing in people with cervicogenic headache and asymptomatic controls

OBJECTIVE

The objective was to determine reliability of sagittal plane range of motion (ROM) assessment in a healthy population and in people with cervicogenic headache (CGH).

METHODS

Upper cervical flexion/extension ROM was measured using an iPhone magnetometer sensor and retraction/protraction ROM measured by linear displacement. Two independent raters evaluated these movements in 33 subjects with CGH and 33 age and gender matched asymptomatic healthy controls on two occasions. Measurement procedures were standardized; and the order of testing randomized. Reliability, standard error of measurement (SEM) and minimum detectable change (MDC) were calculated.

RESULTS

Subjects comprised 30 females and 36 males. The iPhone method demonstrated high reliability (ICC >0.82) with SEM values ranging from 0.62 to 1.0 and MDC values ranging from 1.70 to 4.81 respectively. Evaluation of linear displacement demonstrated moderate reliability (ICC >64). with SEM values ranging from 0.38 to 1.91 and MDC values ranging from 1.05 to 1.63 respectively. Compared to healthy controls, upper cervical flexion, retraction and protraction ROM was significantly less in the CGH group with mean difference of 6.50°, 1.52 cm and 2.34 cm respectively.

DISCUSSION

Upper cervical spine sagittal plane ROM can be measured with moderate to high reliability and was found to be more restricted in people with CGH.

The association between forward head posture and masticatory muscle pressure pain thresholds in patients with temporomandibular joint dissorders: a cross-sectional observational study

OBJECTIVES

Forward head posture (FHP) is common in patients with temporomandibular joint disorders (TMDs); however, whether it contributes to TMD symptoms remains unclear. The aim of this study was to investigate the association between (1) FHP and masticatory muscle pressure pain thresholds (PPTs) and (2) neck muscle and masticatory muscle PPTs.

MATERIALS AND METHODS

A total of 145 patients diagnosed with TMD were recruited between December 2020 and April 2021. Data regarding FHP and neck and masticatory muscle PPTs were collected. FHP was characterized by the craniocervical angle (CVA) measured between the horizontal line through C7 and the line between the tragus of the ear and C7. Patients were divided into either the FHP group (CVA ≤ 51°) or the non-FHP group. Differences in the masseter and temporalis muscle PPTs between the two groups were analyzed using the Mann-Whitney U test. The correlation between the CVA, neck, and masticatory muscle PPTs in all patients was determined by Spearman's correlation analysis.

RESULTS

There were 70 patients in the FHP group and 75 patients in the non-FHP group. No significant difference in masseter and temporalis muscle PPTs was found between the two groups (p > 0.05). No correlation was found between FHP and masticatory muscle PPTs (p > 0.05). A significant association was found between the neck muscle and masticatory muscle PPTs (p < 0.05). The C5-C6 pillar and masticatory PPTs were either moderately (r = 0.435, masseter muscle) or strongly (r = 0.608, temporalis muscle) correlated, while the correlation between the trapezius and masticatory muscles was moderate (r = 0.378, masseter muscle and r = 0.461, temporalis muscle).

CONCLUSION

FHP was not directly associated with masticatory muscle PPTs. Masticatory muscle PPTs were strongly or moderately associated with neck muscle PPTs. Therefore, the presence of neck pain, not the degree of FHP, in patients with TMD is of significance.

CLINICAL RELEVANCE

In TMD treatment, we should pay attention to and actively relieve neck pain.

Effects of clinical pilates exercises in patients with chronic nonspecific neck pain: a randomized clinical trial

BACKGROUND

Neck pain is a common musculoskeletal problem in adults. Clinical pilates exercises can be beneficial managing the pain and improving the risk factors.

AIMS

The aim of this study was to investigate the effects of clinical pilates exercises on pain and disability, deep neck flexor endurance (DNFE), posture, cervical range of motion (CROM), and proprioception in patients with chronic nonspecific neck pain.

METHODS

Fifty patients with chronic nonspecific neck pain were randomized into two groups. The clinical pilates exercise group (CPEG) received clinical pilates exercises for 6 weeks. The control group (CG) received posture education. Pain and disability, DNFE, forward head angle (FHA) and forward shoulder angle (FSA) degrees, CROM, and joint position error (JPE) were measured before and after 6 weeks.

RESULTS

Clinical pilates exercises improved pain, Neck Disability Index (NDI), DNFE, posture, CROM (except extension), and JPE (p < 0.05). We found significant differences between CPEG and CG in the comparisons for the change of pain, NDI, DNFE, FSA, CROM (except extension), and JPE (except left rotation) (p < 0.05). NDI, FSA, and rotational JPE also improved in CG (p < 0.05). However, these improvements were significantly better in CPEG than CG (p < 0.05) except JPE in left rotation (p = 0.118).

CONCLUSION

In patients with chronic nonspecific neck pain, clinical pilates exercise is a safe and effective method to improve pain and disability, DNFE, posture, ROM, and proprioception.

CLINICAL TRIAL REGISTRATION

NCT03782584 retrospectively registered December 20 2018.

The association between forward head posture and non-specific neck pain: A cross-sectional study

BACKGROUND

Poor posture is traditionally associated with various musculoskeletal disorders. Consequently, educators in the musculoskeletal field have been teaching postural observation as part of the physical assessment. Forward head posture (FHP) is hypothesized to be associated with neck pain; however, evidence in this topic remains inconclusive.

PURPOSE

To investigate the association between FHP and neck pain intensity, disability, and cervical kinematics in individuals with neck pain compared to asymptomatic individuals. A secondary aim of this study was to explore the possible effect of a head-mounted display (HMD) used in a virtual reality (VR) assessment on FHP.

METHODS

The study was conducted with 43 volunteers (20 asymptomatic individuals, 23 individuals with neck pain) aged 19 to 62. FHP was assessed by measuring craniovertebral angle on profile photographs. Secondary outcome measures included pain intensity, the neck disability index (NDI) questionnaire, and neck kinematics using specialized VR software.

RESULTS

There were no significant differences between individuals with neck pain and asymptomatic individuals in FHP (craniovertebral angle = 48.24°±7.29; 48.90°±5.89, respectively, p > .05). The neck pain group demonstrated a restricted range of motion and slower neck movements (p < .05). We found no significant correlation between FHP and visual analog scale, NDI, and most neck kinematic measures.

CONCLUSIONS

Our findings cannot support a clinically applicable association between FHP and neck pain. Additionally, individuals with neck pain had a lower range of motion and slower neck movements.

Machine learning approaches applied in spinal pain research

The purpose of this narrative review is to provide a critical reflection of how analytical machine learning approaches could provide the platform to harness variability of patient presentation to enhance clinical prediction. The review includes a summary of current knowledge on the physiological adaptations present in people with spinal pain. We discuss how contemporary evidence highlights the importance of not relying on single features when characterizing patients given the variability of physiological adaptations present in people with spinal pain. The advantages and disadvantages of current analytical strategies in contemporary basic science and epidemiological research are reviewed and we consider how analytical machine learning approaches could provide the platform to harness the variability of patient presentations to enhance clinical prediction of pain persistence or recurrence. We propose that machine learning techniques can be leveraged to translate a potentially heterogeneous set of variables into clinically useful information with the potential to enhance patient management.

A Two Joint Neck Model to Identify Malposition of the Head Relative to the Thorax

Neck pain is a frequent health complaint. Prolonged protracted malpositions of the head are associated with neck pain and headaches and could be prevented using biofeedback systems. A practical biofeedback system to detect malpositions should be realized with a simple measurement setup. To achieve this, a simple biomechanical model representing head orientation and translation relative to the thorax is introduced. To identify the parameters of this model, anthropometric data were acquired from eight healthy volunteers. In this work we determine (i) the accuracy of the proposed model when the neck length is known, (ii) the dependency of the neck length on the body height, and (iii) the impact of a wrong neck length on the models accuracy. The resulting model is able to describe the motion of the head with a maximum uncertainty of 5 mm only. To achieve this high accuracy the effective neck length must be known a priory. If however, this parameter is assumed to be a linear function of the palpable neck length, the measurement error increases. Still, the resulting accuracy can be sufficient to identify and monitor a protracted malposition of the head relative to the thorax.

Effectiveness of clinical Pilates and home exercises in sagittal cervical disorientation: randomized controlled study

Aim: To compare effects of clinical Pilates and home exercises on postural disorders, strength and endurance of deep cervical flexors (DCF), cervical range of motion (CROM), pain intensity and functional disability in sagittal cervical disorientation. Patients & methods: Fourty six patients were included and divided into two groups. Clinical Pilates group performed stabilization based exercise and home exercise group performed conventional exercises. Results: Craniovertebral, head tilt, cervicothoracic angles and strength and endurance of DCF muscles had improvement in favor of clinical Pilates group (p < 0.05). There was no difference between groups in terms of right-left acromial distance, pain intensity, functional disability and CROM parameters (p > 0.05). Conclusion: Clinical Pilates exercises have been found to provide clinically significant improvements in craniovertebral, head tilt, cervicothoracic angles and strength and endurance of DCF muscles. However, in the increase of CROM, decreasing pain severity and functional impairment parameters there was no superiority of both exercise training. Clinical trial registration number: NCT03352921 (Clinicaltrials.gov).

Relationship between Forward Head Posture and Tissue Mechanosensitivity: A Cross-Sectional Study

The relationship between forward head posture (FHP) and neck pain is not clear. FHP could possibly increase the mechanosensitivity of cervical tissues, which could lead to the development of pain depending on the adaptation capability of the central nervous system. The purpose of this study was to analyse the influence of FHP in the mechanosensitivity of articular, muscular, and neural tissues related to the cervical spine. The pressure pain threshold was bilaterally measured in different muscles and nerves and the second cervical vertebrae. The cervical spine’s range of movement was also examined. The measurements were obtained from people with (n = 32) and without (n = 64) FHP. The analyses included a 2-by-2 mixed analysis of variance (ANOVA), pairwise comparisons with Bonferroni correction, and point-biserial correlation coefficients. Subjects with FHP showed a less pressure pain threshold (PPT) in all locations except for the upper trapezius and scalenus medius muscles. They also showed less extension and right-rotation range of motion. There was no association between FHP, neck pain, disability, and headache. Nevertheless, more research is needed to evaluate the relationship between FHP, tissue mechanosensitivity, and neck pain.

Validity and reliability of two Smartphone applications to measure the lower and upper cervical spine range of motion in subjects with chronic cervical pain

BACKGROUND

Cervical pain is the biggest musculoskeletal health problem in industrialised countries. There is an important association between this and decrease in range of motion.

OBJECTIVE

Estimate the validity and reliability intra and inter examiner of two Smartphone apps regarding the measurement of lower and upper cervical spine range of motion in subjects with chronic cervical pain.

METHODS

A cross-sectional study was conducted. The sample consisted of 25 subjects with chronic cervical pain. An examiner made a measurement of the range of motion using the CROM device as a gold standard, afterwards, another examiner did the same using a Smartphone, in order to establish validity. After this, the Smartphone examiner and a new examiner simultaneously conducted the intra and inter examiner reliability.

RESULTS

Measurement of the lower and upper cervical spine range show an excellent validity (> 0.75), with an excellent intra and inter reliability (> 0.75) in all movements except flexion of upper cervical spine (0.75-0.65).

CONCLUSION

The two Smartphone applications used in this study showed an excellent validity compared to the CROM. The intra and inter reliability is excellent for all movements, except for the upper cervical spine flexion.

The Relationship Between Forward Head Posture and Neck Pain: a Systematic Review and Meta-Analysis

PURPOSE OF REVIEW

Forward head posture (FHP) is the most common cervical postural fault in the sagittal plane that is found with different severity levels in almost all populations. Despite claims that FHP may be related to neck pain, this relation seems to be controversial. Thus, our purpose is to determine whether FHP differs between asymptomatic subjects and those with neck pain and to investigate if there is a relationship between head posture and neck pain.

RECENT FINDINGS

A total of 15 cross-sectional studies were eligible for inclusion for this systematic review and meta-analysis. Ten studies compared FHP between a group of asymptomatic participants and a group of participants with neck pain and an overall mean difference (MD) of 4.84 (95% CI = 0.14, 9.54), indicating a significant between-group difference, contrary to adolescent (MD = - 1.05; 95% CI = - 4.23, 2.12). Eight studies showed significant negative correlations between FHP and neck pain intensity (r = - 0.55; 95% CI = - 0.69, - 0.36) as well as disability (r = - 0.42; 95% CI = - 0.54, - 0.28) in adults and older adults, while in adolescents, only lifetime prevalence and doctor visits due to neck pain were significant predictors for FHP. This systematic review found that age played an important role as a confounding factor in the relation between FHP and neck pain. Also, the results showed that adults with neck pain show increased FHP when compared to asymptomatic adults and that FHP is significantly correlated with neck pain measures in adults and older adults. No association was found between FHP and most of neck pain measures in adolescents.

Reliability and validity of clinical tests to assess posture, pain location, and cervical spine mobility in adults with neck pain and its associated disorders: Part 4. A systematic review from the cervical assessment and diagnosis research evaluation (CADRE) collaboration

PURPOSE

To determine the reliability and validity of clinical tests to assess posture, pain location, and cervical spine mobility in adults with grades I-IV neck pain and associated disorders (NAD).

METHODS

We systematically searched electronic databases to update the systematic review of the Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders. Eligible reliability and validity studies were critically appraised using modified versions of the QAREL and QUADAS-2 instruments, respectively. Evidence from low risk of bias studies were synthesized following best evidence synthesis principles.

RESULTS

We screened 14302 articles, critically appraised 46 studies, and found 32 low risk of bias articles (14 reliability and 18 validity studies). We found preliminary evidence of: 1) reliability of visual inspection, aided with devices (CROM and digital caliper) to assess head posture; 2) reliability and validity of soft tissue palpation to locate tender/trigger points in muscles; 3) reliability and validity of joint motion palpation to assess stiffness and pain provocation in combination; and 4) range of motion tests using visual estimation (in cervical extension only) or devices (digital caliper, goniometer, inclinometer) to assess cervical mobility.

CONCLUSIONS

We found little evidence to support the reliability and validity of clinical tests to assess head posture, pain location and cervical mobility in adults with NAD grades I-III. More advanced validity studies are needed to inform the clinical utility of tests used to evaluate patients with NAD.

Effects of McKenzie exercise, Kinesio taping, and myofascial release on the forward head posture

[Purpose] This study aimed to investigate the effects of McKenzie exercise, Kinesio taping, and myofascial release (MFR) on forward head posture (FHP). [Participants and Methods] Twenty-eight individuals with an FHP were enrolled. participants were randomly assigned to one of three groups: Group A, Group B and Group C. Group A underwent McKenzie exercise and MFR. Group B underwent McKenzie exercise and Kinesio taping. Group C underwent McKenzie exercise, MFR, and Kinesio taping. Interventions for all three groups were provided three times per week for four weeks. The acromion and tragus of ear (A-T length), craniovertebral angle (CVA), Cranial rotation angle (CRA), and neck disability index (NDI) were measured. [Results] The A-T length significantly differed after intervention in all three groups. CVA only significantly differed after intervention in group C. All three groups showed an increase in CRA after intervention; however, these increases were not statistically significant. [Conclusion] Considering these results, these three types of exercise may be recommended as effective exercises to improve posture in adults with FHP.

Reliability of forward head posture evaluation while sitting, standing, walking and running

Forward head posture has been evaluated mostly by visual observation or simple non-invasive measurements without a standardized evaluation method or protocol. In this experimental study, the reliability of existing forward head-posture measurement methods was evaluated by computing the intra-class correlation coefficients of three different head-position variables (two horizontal gap variables and one head-orientation variable) in seven different posture conditions from 20 asymptomatic participants. The position variables of the head were measured three times using a three-dimensional motion capture system while sitting comfortably, sitting with the back straight, standing comfortably, standing with the back straight, walking at 4 and 6km/h on a treadmill, and running at 8km/h on a treadmill. Intra-class correlation coefficients between repetitive measures ranged from 0.81 to 0.96, and high correlation coefficient values (>0.9) were produced when the head-position variables were measured during straight sitting, straight standing, and walking at 6km/h. Among the three head-position variables, a horizontal gap between the tragus and the 7th cervical vertebra was recorded more consistently than other variables. Results of this study highlight the importance of a standardized evaluation protocol for more reliable assessment of the forward head posture.

Male and Female Cervical Spine Biomechanics and Anatomy: Implication for Scaling Injury Criteria

There is an increased need to develop female-specific injury criteria and anthropomorphic test devices (dummies) for military and automotive environments, especially as women take occupational roles traditionally reserved for men. Although some exhaustive reviews on the biomechanics and injuries of the human spine have appeared in clinical and bioengineering literatures, focus has been largely ignored on the difference between male and female cervical spine responses and characteristics. Current neck injury criteria for automotive dummies for assessing crashworthiness and occupant safety are obtained from animal and human cadaver experiments, computational modeling, and human volunteer studies. They are also used in the military. Since the average human female spines are smaller than average male spines, metrics specific to the female population may be derived using simple geometric scaling, based on the assumption that male and female spines are geometrically scalable. However, as described in this technical brief, studies have shown that the biomechanical responses between males and females do not obey strict geometric similitude. Anatomical differences in terms of the structural component geometry are also different between the two cervical spines. Postural, physiological, and motion responses under automotive scenarios are also different. This technical brief, focused on such nonuniform differences, underscores the need to conduct female spine-specific evaluations/experiments to derive injury criteria for this important group of the population.

Characteristics of the Motor Units during Sternocleidomastoid Isometric Flexion among Patients with Mechanical Neck Disorder and Asymptomatic Individuals

Mechanical neck disorder is a widespread and non-neurological musculoskeletal condition resulting from modern lifestyles. Presently, the fundamental electrophysiological properties of the motor units of the sternocleidomastoid muscles and the characteristics of the short-term synchronization of the motor unit in patients with neck pain are ambiguous. This study therefore aims to clarify the fundamental electrophysiological properties of the motor units of the sternocleidomastoid muscles in patients with mechanical neck disorder and in asymptomatic individuals. We further investigated whether alterations in the degree of motor unit short-term synchronization occur. The surface electrophysiological signals of the bilateral sternal heads of the sternocleidomastoid muscles of twelve patients with mechanical neck disorder and asymptomatic individuals were detected at 25% of the maximum voluntary contraction during cervical isometric flexion and then decomposed into individual motor unit action potential trains. We found that the patients with mechanical neck disorder showed significantly higher initial and mean firing rates of the sternocleidomastoid muscles and displayed substantially lower motor unit short-term synchronization values compared with the asymptomatic subjects. Consequently, these convincing findings support the assertion that patients with mechanical neck disorder display altered neuromuscular control strategies, such as the reinforcement of motor unit recruitment firing rates in the sternocleidomastoid muscles. The motor units of these patients also revealed neural recruitment strategies with relatively poor efficiency when executing the required motor tasks.

Neck Posture Clusters and Their Association With Biopsychosocial Factors and Neck Pain in Australian Adolescents

BACKGROUND

There is conflicting evidence on the association between sagittal neck posture and neck pain.

OBJECTIVE

The purposes of this study were: (1) to determine the existence of clusters of neck posture in a cohort of 17-year-olds and (2) to establish whether identified subgroups were associated with biopsychosocial factors and neck pain.

DESIGN

This was a cross-sectional study.

METHODS

The adolescents (N=1,108) underwent 2-dimensional photographic postural assessment in a sitting position. One distance and 4 angular measurements of the head, neck, and thorax were calculated from photo-reflective markers placed on bony landmarks. Subgroups of sagittal sitting neck posture were determined by cluster analysis. Height and weight were measured, and lifestyle and psychological factors, neck pain, and headache were assessed by questionnaire. The associations among posture subgroups, neck pain, and other factors were evaluated using logistic regression.

RESULTS

Four distinct clusters of sitting neck posture were identified: upright, intermediate, slumped thorax/forward head, and erect thorax/forward head. Significant associations between cluster and sex, weight, and height were found. Participants classified as having slumped thorax/forward head posture were at higher odds of mild, moderate, or severe depression. Participants classified as having upright posture exercised more frequently. There was no significant difference in the odds of neck pain or headache across the clusters.

LIMITATIONS

The results are specific to 17-year-olds and may not be applicable to adults.

CONCLUSION

Meaningful sagittal sitting neck posture clusters were identified in 17-year-olds who demonstrated some differences with biopsychosocial profiling. The finding of no association between cluster membership and neck pain and headaches challenges widely held beliefs about the role of posture in adolescent neck pain.

Sensitivity to Differences in the Extent of Neck-Retraction and -Rotation Movements Made with and without Vision

19 subjects (10 men, 9 women) ages 19 to 30 years ( M = 23.2, SD = 3.3) volunteered to participate in a study to investigate the just-noticeable-difference in movement extent for neck retraction and neck rotation. Testing was carried out with stopped movements, conducted according to the method of constant stimuli, and repeated both with and without vision in a comfortable seated position. Sensitivity was greatest for neck-retraction movements, which had lower just-noticeable-difference than either left or right rotation movements. Having full vision available gave no significant advantage in any direction when discriminating between different extents of midrange head movements.

Relationships between craniocervical posture and pain-related disability in patients with cervico-craniofacial pain

Objectives

This cross-sectional correlation study explored the relationships between craniocervical posture and pain-related disability in patients with chronic cervico-craniofacial pain (CCFP). Moreover, we investigated the test–retest intrarater reliability of two craniocervical posture measurements: head posture (HP) and the sternomental distance (SMD).

Methods

Fifty-three asymptomatic subjects and 60 CCFP patients were recruited. One rater measured HP and the SMD using a cervical range of motion device and a digital caliper, respectively. The Spanish versions of the neck disability index and the craniofacial pain and disability inventory were used to assess pain-related disability (neck disability and craniofacial disability, respectively).

Results

We found no statistically significant correlations between craniocervical posture and pain-related disability variables (HP and neck disability [r=0.105; P>0.05]; HP and craniofacial disability [r=0.132; P>0.05]; SMD and neck disability [r=0.126; P>0.05]; SMD and craniofacial disability [r=0.195; P>0.05]). A moderate positive correlation was observed between HP and SMD for both groups (asymptomatic subjects, r=0.447; CCFP patients, r=0.52). Neck disability was strongly positively correlated with craniofacial disability (r=0.79; P<0.001). The test–retest intrarater reliability of the HP measurement was high for asymptomatic subjects and CCFP patients (intraclass correlation coefficients =0.93 and 0.81, respectively) and for SMD (intra-class correlation coefficient range between 0.76 and 0.99); the test–retest intrarater reliability remained high when evaluated 9 days later. The HP standard error of measurement range was 0.54–0.75 cm, and the minimal detectable change was 1.27–1.74 cm. The SMD standard error of measurement was 2.75–6.24 mm, and the minimal detectable change was 6.42–14.55 mm. Independent t-tests showed statistically significant differences between the asymptomatic individuals and CCFP patients for measures of craniocervical posture, but these differences were very small (mean difference =1.44 cm for HP; 6.24 mm for SMD). The effect sizes reached by these values were estimated to be small for SMD (d=0.38) and medium for HP (d=0.76).

Conclusion

The results showed no statistically significant correlations between craniocervical posture and variables of pain-related disability, but a strong correlation between the two variables of disability was found. Our findings suggest that small differences between CCFP patients and asymptomatic subjects exist with respect to the two measurements used to assess craniocervical posture (HP and SMD), and these measures demonstrated high test–retest intrarater reliability for both CCFP patients and asymptomatic subjects.

Extension and flexion in the upper cervical spine in neck pain patients

Neck pain is a common problem in the general population with high risk of ongoing complaints or relapses. Range of motion (ROM) assessment is scientifically established in the clinical process of diagnosis, prognosis and outcome evaluation in neck pain. Anatomically, the cervical spine (CS) has been considered in two regions, the upper and lower CS. Disorders like cervicogenic headache have been clinically associated with dysfunctions of the upper CS (UCS), yet ROM tests and measurements are typically conducted on the whole CS. A cross-sectional study assessing 19 subjects with non-specific neck pain was undertaken to examine UCS extension-flexion ROM in relation to self-reported disability and pain (via the Neck Disability Index (NDI)). Two measurement devices (goniometer and electromagnetic tracking) were employed and compared. Correlations between ROM and the NDI were stronger for the UCS compared to the CS, with the strongest correlation between UCS flexion and the NDI-headache (r = -0.62). Correlations between UCS and CS ROM were fair to moderate, with the strongest correlation between UCS flexion and CS extension ROM (r = -0.49). UCS flexion restriction is related to headache frequency and intensity. Consistency and agreement between both measurement systems and for all tests was high. The results demonstrate that separate UCS ROM assessments for extension and flexion are useful in patients with neck pain.

Chronic neck pain in young adults: perspectives on anatomic differences

BACKGROUND CONTEXT

Neck pain (NP) is a common musculoskeletal disorder, but little is known about the associated risk factors.

PURPOSE

We compared anatomic differences in the neck and trunk area of young adult patients with chronic NP and control subjects without NP to identify risk factors and predictors.

STUDY DESIGN

This is an age-, sex-, and body mass index-matched retrospective case-control study of a consecutive sample.

PATIENT SAMPLE

Patients with axial NP for longer than 6 months (23 males and 25 females) and pain-free volunteers (23 males and 25 females) were included.

OUTCOME MEASURES

Outcome measures were linear and angular dimensions of the cervicothoracic junction.

METHODS

Midsagittal magnetic resonance imaging scans of the cervicothoracic spine were obtained. Four linear and four angular parameters were identified and measured. These parameters included depth of the T1-manubrium arch (T1AD), depth of the thoracic cage (TXD), tangential height of T1 (T1H1), relative height of T1 (T1H2), T1 slope (T1S), thoracic inlet inclination (TiI), T1-manubrium arch inclination (T1AI), and the angular difference between TiI and T1AI (TiI-T1AI). The measurements were taken by two neurosurgeons.

RESULTS

Depth of the T1-manubrium arch and TiI were identified as predictors for NP in the binary logistic regression analysis. Each millimeter increase in T1AD lessened the probability of NP with an adjusted odds ratio (OR) of 0.823 (95% confidence interval [CI], 0.701-0.966) in females and 0.809 (95% CI, 0.681-0.959) in males. Each degree increase in TiI was associated with the probability of NP with an adjusted OR of 1.247 (95% CI, 1.060-1.466) in males.

CONCLUSIONS

Measurement of cervicothoracic junctional structures is a reliable and feasible method of estimating potential predictor of chronic NP in young adults. Forward inclination of the thoracic inlet in males and a shallow thoracic cage in females were identified as important predictors.

Anthropometric specifications, development, and evaluation of EvaRID--a 50th percentile female rear impact finite element dummy model

OBJECTIVES

Whiplash-associated disorders (WADs), or whiplash injuries, due to low-severity vehicle crashes are of great concern in motorized countries and it is well established that the risk of such injuries is higher for females than for males, even in similar crash conditions. Recent protective systems have been shown to be more beneficial for males than for females. Hence, there is a need for improved tools to address female WAD prevention when developing and evaluating the performance of whiplash protection systems. The objective of this study is to develop and evaluate a finite element model of a 50th percentile female rear impact crash test dummy.

METHODS

The anthropometry of the 50th percentile female was specified based on literature data. The model, called EvaRID (female rear impact dummy), was based on the same design concept as the existing 50th percentile male rear impact dummy, the BioRID II. A scaling approach was developed and the first version, EvaRID V1.0, was implemented. Its dynamic response was compared to female volunteer data from rear impact sled tests.

RESULTS

The EvaRID V1.0 model and the volunteer tests compared well until ∼250 ms of the head and T1 forward accelerations and rearward linear displacements and of the head rearward angular displacement. Markedly less T1 rearward angular displacement was found for the EvaRID model compared to the female volunteers. Similar results were received for the BioRID II model when comparing simulated responses with experimental data under volunteer loading conditions. The results indicate that the biofidelity of the EvaRID V1.0 and BioRID II FE models have limitations, predominantly in the T1 rearward angular displacement, at low velocity changes (7 km/h). The BioRID II model was validated against dummy test results in a loading range close to consumer test conditions (EuroNCAP) and lower severity levels of volunteer testing were not considered.

CONCLUSIONS

The EvaRID dummy model demonstrated the potential of becoming a valuable tool when evaluating and developing seats and whiplash protection systems. However, updates of the joint stiffness will be required to provide better correlation at lower load levels. Moreover, the seated posture, curvature of the spine, and head position of 50th percentile female occupants needs to be established and implemented in future models.

Effects of strength and endurance training of superficial and deep neck muscles on muscle activities and pain levels of females with chronic neck pain

[Purpose] To compare muscle activities and pain levels of females with chronic neck pain receiving different exercise programs. [Subjects and Methods] One hundred females with chronic neck pain participated in this study. They were randomly allocated into 4 groups (n = 25) on the basis of the exercises performed as follows: strength-endurance exercise, craniocervical flexion exercise, combination of strength-endurance and craniocervical flexion exercise and control groups. Pain, disability levels and changes in the muscle activities of the cervical erector spinae (CE), sternocleidomastoid (SCM), anterior scalenes (AS) and upper trapezius (UT) muscles were evaluated before and after the interventions. [Results] After 12 weeks of exercise intervention, all three exercise groups showed improvements in pain and disability. The muscle activities during the typing task were significantly different from the control group in all three exercise groups for all muscles except those of the extensor muscles in the craniocervical flexion exercise group. [Conclusion] The results of this study indicate that exercises for the cervical muscles improve pain and disability. The exercise programs reduced the activities of almost all cervical muscles.

A new concept for quantifying the complicated kinematics of the cervical spine and its application in evaluating the impairment of clients with mechanical neck disorders

Mechanical neck disorder (MND) is one of the most common health issues and is characterized by restricted cervical mobility. However, traditional kinematic information often focuses on primary movement in the cardinal plane, which seems insufficient to fully determine the kinematics of the cervical spine because of the complexity of the anatomical structures involved. Therefore, the current investigation aimed to modify the concept of the three-dimensional workspace to propose an objective mathematical model to quantify the complicated kinematics of the cervical spine. In addition, the observation evaluated the characteristics of the cervical workspace in asymptomatic and MND groups. Seventeen healthy volunteers and twenty-five individuals with MND participated in the study and executed the motion of circumduction to establish the cervical workspace using an electromagnetic tracking system. The results produced a mathematical model to successfully quantify the cervical workspace. Moreover, MND groups demonstrated significant reduction in the normalization of the cervical workspace with respect to the length of the head-cervical complex. Accordingly, the current study provided a new concept for understanding the complicated kinematics of the cervical spine. The cervical workspace could be a useful index to evaluate the extent of impairment of the cervical spine and monitor the efficacy of rehabilitation programs for patients with MND.

Reliability of measuring the cervical sagittal translation mobility with a simple method in a clinical setting

Introduction. The cervical sagittal translation mobility is related to neck pain. A practical method for measuring the specific cervical mobility is needed. The aim was to describe a simple method for measuring the cervical sagittal translation mobility and to evaluate its reliability in a clinical setting. Method. The head protraction and retraction ranges of thirty healthy seated subjects were measured from a dorsal reference plane by two physiotherapists utilizing a tape measure. A standard inclinometer/goniometer was used to minimize angular movements of the head during the translational movements. The measurements were made twice for each subject with a two-hours interval between each measurement. The inter-rater and intra-rater agreements were evaluated with intraclass correlation coefficients (ICCs) and with the distribution of the difference of the measurements. The systematic differences were analysed with the Wilcoxon signed rank test. Results. The intra-rater agreement was good. The inter-rater agreement was moderate in the first measurement and good in the second. A systematic difference was noted between raters in the first measurement but not in the second, possibly indicating a learning effect. Discussion. The method used in the study is simple and reliable and can be recommended for clinical use.

Motion of the head and neck of female and male volunteers in rear impact car-to-car impacts

OBJECTIVES

The objectives of this study were to quantify and compare dynamic motion responses between 50th percentile female and male volunteers in rear impact tests. These data are fundamental for developing future occupant models for crash safety development and assessment.

METHODS

High-speed video data from a rear impact test series with 21 male and 21 female volunteers at 4 and 8 km/h, originally presented in Siegmund et al. (1997), were used for further analysis. Data from a subset of female volunteers, 12 at 4 km/h and 9 at 8 km/h, were extracted from the original data set to represent the 50th percentile female. Their average height was 163 cm and their average weight was 62 kg. Among the male volunteers, 11 were selected, with an average height of 175 cm and an average weight of 73 kg, to represent the 50th percentile male. Response corridors were generated for the horizontal and angular displacements of the head, T1 (first thoracic vertebra), and the head relative to T1. T-tests were performed with the statistical significance level of .05 to quantify the significance of the differences in parameter values for the males and females.

RESULTS

Several differences were found in the average motion response of the male and female volunteers at 4 and 8 km/h. Generally, females had smaller rearward horizontal and angular motions of the head and T1 compared to the males. This was mainly due to shorter initial head-to-head restraint distance and earlier head-to-head restraint contact for the females. At 8 km/h, the female volunteers showed 12 percent lower horizontal peak rearward head displacement (P = .018); 22 percent lower horizontal peak rearward head relative to T1 displacement (P = .018); and 30 percent lower peak head extension angle (P = .001). The females also had more pronounced rebound motion.

CONCLUSIONS

This study indicates that there may be characteristic differences in the head-neck motion response between 50th percentile males and females in rear impacts. The exclusive use of 50th percentile male rear impact dummies may thus limit the assessment and development of whiplash prevention systems that adequately protect both male and female occupants. The results of this study could be used in the development and evaluation of a mechanical and/or computational average-sized female dummy model for rear impact safety assessment. These models are used in the development and evaluation of protective systems. It would be of interest to make further studies into seat configurations featuring a greater head-to-head restraint distance.

The efficacy of forward head correction on nerve root function and pain in cervical spondylotic radiculopathy: a randomized trial

Objective: To investigate the effect of forward head posture correction on pain and nerve root function in cases of cervical spondylotic radiculopathy.

Design: A randomized controlled study with six months follow-up.

Setting: University research laboratory.

Subjects: Ninety-six patients with unilateral lower cervical spondylotic radiculopathy (C5–C6 and C6–C7) and craniovertebral angle measured less than or equal to 50° were randomly assigned to an exercise or a control group.

Interventions: The control group ( n = 48) received ultrasound and infrared radiation, whereas the exercise group ( n = 48) received a posture corrective exercise programme in addition to ultrasound and infrared radiation.

Main outcome measures: The peak-to-peak amplitude of dermatomal somatosensory evoked potentials, craniovertebral angle, visual analogue scale were measured for all patients at three intervals (before treatment, after 10 weeks of treatment, and at follow-up of six months).

Results: There was a significant difference between groups adjusted to baseline value of outcome at 10 weeks post-treatment for craniovertebral angle, pain, C6 and C7 peak-to-peak amplitude of dermatomal somatosensory evoked potentials P = 0.000, 0.01, 0.000, 0.001 respectively and at follow-up for all previous variables ( P = 0.000).

Conclusion: Forward head posture correction using a posture corrective exercise programme in addition to ultrasound and infrared radiation decreased pain and craniovertebral angle and increased the peak-to-peak amplitude of dermatomal somatosensory evoked potentials for C6 and C7 in cases of lower cervical spondylotic radiculopathy.

Assessment of patients with neck pain: a review of definitions, selection criteria, and measurement tools

OBJECTIVE

The purpose of this literature review was to synthesize the existing literature on various definitions, classifications, selection criteria, and outcome measures used in different studies in patients with neck pain.

METHODS

A literature search of MEDLINE and CINAHL through September 2008 was performed to gather articles on the reliability, validity, and utility of a wide variety of outcome measurements for neck pain.

RESULTS

Different types of definitions appear in the literature based on anatomical location, etiology, severity, and duration of symptoms. Classifications according to severity and duration of pain and the establishment of selection criteria seem to play a crucial role in study designs and in clinical settings to ensure homogeneous groups and effective interventions. A series of objective tests and subjective self-report measures are useful in assessing physical abilities, pain, functional ability, psychosocial well-being, general health status, and quality of life in patients with neck pain. Self-administered questionnaires are commonly used in clinical practice and research projects.

CONCLUSIONS

Because of multidimensionality of chronic neck pain, more than just one index may be needed to gain a complete health profile of the patient with neck pain. The instruments chosen should be reliable, valid, and able to evaluate the effects of treatment.

Variability of the forward head posture in healthy community-dwelling older women

PURPOSE

The purpose of this research was to describe the variability of forward head posture in healthy older women, and to investigate the influence of age on variability.

METHODS

This cross-sectional descriptive study included 187 healthy community-dwelling women volunteers ranging in age from 65-96 years. The forward head posture (FHP) measurement was derived from a sagittal photograph. The subjects were asked to perform a series of standing activities, and the photograph was taken while the subjects were performing these activities. Data analysis included descriptive analysis, FHP measurement analysis for normalcy, one-factor ANOVA with FHP by age group, post-hoc Tukey analysis, and trend analysis for the age-FHP relationship.

RESULTS

Three age-group normative FHP means were identified: 48.84 degrees (SE 0.97) for the 65-74 year old group, 41.20 degrees (SE 0.78) for the 75-84 year old group, and 35.60 degrees (SE 1.76) for the 85+ year group. Significant differences were found in the FHP between these age groups. A subsequent trend analysis demonstrated a linear relationship between age and the FHP, with older women demonstrating a more severe FHP.

CONCLUSIONS

Age-associated variability in the FHP of healthy elderly women has been identified. The FHP values determined by this research may serve as normative guidelines for clinicians when conducting postural assessments, and in clinical decision-making regarding possible interventions.

Head posture and neck pain of chronic nontraumatic origin: a comparison between patients and pain-free persons

OBJECTIVE

To compare standing head posture measurements between patients with nontraumatic neck pain (NP) and pain-free individuals.

DESIGN

Single-blind (assessor) cross-sectional study.

SETTING

Hospital and general community.

PARTICIPANTS

Consecutive patients (n=40) with chronic nontraumatic NP and age- and sex-matched pain-free participants (n=40).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Three angular measurements: the angle between C7, the tragus of the ear, and the horizontal; the angle between the tragus of the ear, the eye, and the horizontal; and the angle between the inferior margins of the right and the left ear and the horizontal were calculated through the digitization of video images.

RESULTS

NP patients were found to have a significantly smaller angle between C7, the tragus, and the horizontal, resulting in a more forward head posture than pain-free participants (NP, mean +/- SD, 45.4 degrees +/-6.8 degrees ; pain-free, mean +/- SD, 48.6 degrees +/-7.1 degrees ; P<.05; confidence interval [CI] for the difference between groups, 0.9 degrees -6.3 degrees ). Dividing the population according to age into younger (</=50y) and older (>50y) revealed an interaction, with a statistically significant difference in head posture for younger participants with NP compared with younger pain-free participants (NP, mean +/- SD, 46.1 degrees +/-6.7 degrees ; pain-free, mean +/- SD, 51.8 degrees +/-5.9 degrees ; P<.01; CI for the difference between groups, 1.8 degrees -9.7 degrees ) but no difference for the older group (NP, mean +/- SD, 44.8 degrees +/-7.1 degrees ; pain-free, mean +/- SD, 45.1 degrees +/-6.7 degrees ; P>.05; CI for the difference between groups, -4.9 degrees -4.2 degrees ). No other differences were found between patients and pain-free participants.

CONCLUSIONS

Younger patients with chronic nontraumatic NP were shown to have a more forward head posture in standing than matched pain-free participants. However, the difference, although statistically significant, was perhaps too small to be clinically meaningful.

Assessment of neck pain and its associated disorders: results of the Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders

STUDY DESIGN

Best evidence synthesis.

OBJECTIVE

To critically appraise and synthesize the literature on assessment of neck pain.

SUMMARY OF BACKGROUND DATA

The published literature on assessment of neck pain is large and of variable quality. There have been no prior systematic reviews of this literature.

METHODS

The Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders conducted a critical review of the literature (published 1980-2006) on assessment tools and screening protocols for traumatic and nontraumatic neck pain.

RESULTS

We found 359 articles on assessment of neck pain. After critical review, 95 (35%) were judged scientifically admissible. Screening protocols have high predictive values to detect cervical spine fracture in alert, low-risk patients seeking emergency care after blunt neck trauma. Computerized tomography (CT) scans had better validity (in adults and elderly) than radiographs in assessing high-risk and/or multi-injured blunt trauma neck patients. In the absence of serious pathology, clinical physical examinations are more predictive at excluding than confirming structural lesions causing neurologic compression. One exception is the manual provocation test for cervical radiculopathy, which has high positive predictive value. There was no evidence that specific MRI findings are associated with neck pain, cervicogenic headache, or whiplash exposure. No evidence supports using cervical provocative discography, anesthetic facet, or medial branch blocks in evaluating neck pain. Reliable and valid self-report questionnaires are useful in assessing pain, function, disability, and psychosocial status in individuals with neck pain.

CONCLUSION

The scientific evidence supports screening protocols in emergency care for low-risk patients; and CT-scans for high-risk patients with blunt trauma to the neck. In nonemergency neck pain without radiculopathy, the validity of most commonly used objective tests is lacking. There is support for subjective self-report assessment in monitoring patients' course, response to treatment, and in clinical research.

Effect of global posture reeducation and of static stretching on pain, range of motion, and quality of life in women with chronic neck pain: a randomized clinical trial

PURPOSE

Compare the effect of conventional static stretching and muscle chain stretching, as proposed by the global posture reeducation method, in the manual therapy of patients with chronic neck pain.

METHODS

Thirty-three female patients aged 35 to 60 years old, 31 of whom completed the program, were randomly divided into two groups: The global posture reeducation group (n=15) performed muscle chain stretching, while the conventional stretching group (n=16) performed conventional static muscle stretching. Both groups also underwent manual therapy. Patients were evaluated before and after treatment and at a six-week follow-up appointment and tested for pain intensity (by means of visual analog scale), range of motion (by goniometry), and health-related quality of life (by the SF-36 questionnaire). The treatment program consisted of two 1-hour individual sessions per week for six weeks. Data were statistically analyzed at a significance level of p<0.05.

RESULTS

Significant pain relief and range of motion improvement were observed after treatment in both groups, with a slight reduction at follow-up time. Quality of life also improved after treatment, except for the global posture reeducation group in one domain; at follow-up, there was improvement in all domains, except that both groups reported increased pain. There were no significant differences between groups

CONCLUSION

Conventional stretching and muscle chain stretching in association with manual therapy were equally effective in reducing pain and improving the range of motion and quality of life of female patients with chronic neck pain, both immediately after treatment and at a six-week follow-up, suggesting that stretching exercises should be prescribed to chronic neck pain patients.

The relationship between head posture and severity and disability of patients with neck pain

STUDY DESIGN

A cross-sectional correlation study.

OBJECTIVES

To investigate the relationship between head posture with pain and disability in patients with neck pain.

METHOD

Sixty-two subjects with neck pain and 52 normal subjects were recruited by convenience sampling. The forward head posture was measured via the craniovertebral (CV) angle by using the Head Posture Spinal Curvature Instrument (HPSCI). The Chinese version of Northwick Park Neck Pain Questionnaire (NPQ) and Numeric Pain Rating Scale (NPRS) were used to assess neck pain disability and severity. The difference in CV angles between the two groups and Pearson's correlation coefficient between the CV angle, NPQ and NPRS were determined.

RESULTS

There was a significant difference in the CV angle between subjects with and without neck pain. CV angle was negatively correlated with NPQ (r(p)=-0.3101, p=0.015) and NPRS (r(p)=-0.329,p=0.009). It was also negatively correlated with age (r(p)=-0.380,p=0.002). When age was taken into account, the CV angle was negatively correlated with NPQ (r(p)=-0.3101,p=0.015) but showed no significant correlation with NPRS (r(p)=-0.1848,p=0.154).

CONCLUSION

The CV angle in subjects with neck pain is significantly smaller than that in normal subjects. There is moderate negative correlation between CV angle and neck disability. Patients with small CV angle have a greater forward head posture, and the greater the forward head posture, the greater the disability.

Assessment of neck pain and its associated disorders: results of the Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders

STUDY DESIGN

Best evidence synthesis.

OBJECTIVE

To critically appraise and synthesize the literature on assessment of neck pain.

SUMMARY OF BACKGROUND DATA

The published literature on assessment of neck pain is large and of variable quality. There have been no prior systematic reviews of this literature.

METHODS

The Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders conducted a critical review of the literature (published 1980-2006) on assessment tools and screening protocols for traumatic and nontraumatic neck pain.

RESULTS

We found 359 articles on assessment of neck pain. After critical review, 95 (35%) were judged scientifically admissible. Screening protocols have high predictive values to detect cervical spine fracture in alert, low-risk patients seeking emergency care after blunt neck trauma. Computerized tomography (CT) scans had better validity (in adults and elderly) than radiographs in assessing high-risk and/or multi-injured blunt trauma neck patients. In the absence of serious pathology, clinical physical examinations are more predictive at excluding than confirming structural lesions causing neurologic compression. One exception is the manual provocation test for cervical radiculopathy, which has high positive predictive value. There was no evidence that specific MRI findings are associated with neck pain, cervicogenic headache, or whiplash exposure. No evidence supports using cervical provocative discography, anesthetic facet, or medial branch blocks in evaluating neck pain. Reliable and valid self-report questionnaires are useful in assessing pain, function, disability, and psychosocial status in individuals with neck pain.

CONCLUSION

The scientific evidence supports screening protocols in emergency care for low-risk patients; and CT-scans for high-risk patients with blunt trauma to the neck. In nonemergency neck pain without radiculopathy, the validity of most commonly used objective tests is lacking. There is support for subjective self-report assessment in monitoring patients' course, response to treatment, and in clinical research.

Associated sagittal spinal movements in performance of head pro- and retraction in healthy women: A kinematic analysis

Sagittal head excursions are frequently used as diagnostic and treatment tools by physiotherapists. Retractions are performed to promote good head-on-body orientation. This study examined the regional contribution of spinal movements to head pro- and retraction in addition to the effect of a more or less restrained sitting position in healthy women. Fourteen healthy women performed seven sagittal head excursions in a more or less restrained sitting position, during which time their kinematic response was measured with an optoelectronic system. Total anterior/posterior head excursion was smaller (P=0.005) in the more restrained sitting position. In both sitting positions, approximately 60% of the total anterior/posterior head excursion originated from the cervical spine, almost 30% from the cervicothoracic spine C7-T4, and approximately 10% from thoracic regions down to T12. Middle thoracic vertical displacement was smaller (p=0.005) in the more restrained sitting position. A high correlation was found between total head excursion and the cervicothoracic unit displacements in both sitting positions (r=0.79, r=0.85, respectively). In each sitting position, the craniovertebral angle, and the tragus-C7-horizontal line decreased in protraction. Movements in the thoracic region contributed to the total head excursion. Therefore, clinicians should recognize the thoracic contribution to sagittal head excursion when using pro- and retraction as a diagnostic and treatment tool.

Effect of neck exercise on sitting posture in patients with chronic neck pain

BACKGROUND AND PURPOSE

Poor sitting posture has been implicated in the development and perpetuation of neck pain symptoms. This study had 2 purposes: (1) to compare change in cervical and thoracic posture during a distracting task between subjects with chronic neck pain and control subjects and (2) to compare the effects of 2 different neck exercise regimens on the ability of people with neck pain to maintain an upright cervical and thoracic posture during this task.

SUBJECTS

Fifty-eight subjects with chronic, nonsevere neck pain and 10 control subjects participated in the study.

METHOD

Change in cervical and thoracic posture from an upright posture was measured every 2 minutes during a 10-minute computer task. Following baseline measurements, the subjects with neck pain were randomized into one of two 6-week exercise intervention groups: a group that received training of the craniocervical flexor muscles or a group that received endurance-strength training of the cervical flexor muscles. The primary outcomes following intervention were changes in the angle of cervical and thoracic posture during the computer task.

RESULTS

Subjects with neck pain demonstrated a change in cervical angle across the duration of the task (mean=4.4 degrees ; 95% confidence interval [CI]=3.3-5.4), consistent with a more forward head posture. No significant difference was observed for the change in cervical angle across the duration of the task for the control group subjects (mean=2.2 degrees ; 95% CI=1.0-3.4). Following intervention, the craniocervical flexor training group demonstrated a significant reduction in the change of cervical angle across the duration of the computer task.

DISCUSSION AND CONCLUSION

This study showed that people with chronic neck pain demonstrate a reduced ability to maintain an upright posture when distracted. Following intervention with an exercise program targeted at training the craniocervical flexor muscles, subjects with neck pain demonstrated an improved ability to maintain a neutral cervical posture during prolonged sitting.

Neck muscle endurance, self-report, and range of motion data from subjects with treated and untreated neck pain

BACKGROUND

Despite the high prevalence and cost of neck-pain problems, there is currently little data available on the physical characteristics associated with different levels of neck pain.

OBJECTIVE

To investigate associations between categories of response to neck pain/discomfort and (1) the endurance time of neck muscles, neck range of motion (ROM), and neck and head morphology, (2) sensitization or stretch effects arising from repeating end-of-range measurements, and (3) self-report data from neck pain and disability questionnaires.

DESIGN

A cross-sectional study design.

METHODS

Fifty-five Australian volunteers with and without neck pain, who were not taking time off work, were measured for neck muscle endurance, active neck ROM, craniocervical and thoracic posture, neck length, and head circumference and completed questionnaires about any neck pain/discomfort and disability.

RESULTS

Twenty-two subjects reported a level of neck pain/discomfort that had required treatment (treated neck pain), a group of 17 subjects reported experiencing low-level neck pain/discomfort on a recurrent basis for which they had not sought treatment (untreated neck pain), whereas 16 subjects had no experience of neck pain or discomfort (no pain). Neck muscle endurance time was significantly lower for both pain groups. The affective dimension of the Short-Form McGill Pain Questionnaire and neck disability questionnaires were scored significantly higher by subjects who had sought treatment than by those in either of the untreated groups. Both pain groups showed a range decrease for most directions of neck motion at second measurement.

CONCLUSIONS

Neck muscle endurance times, repeated end-ROM testing, the Short-Form McGill Pain Questionnaire, and disability questionnaires may distinguish between groups with untreated, treated, and no neck pain.

The effect of postural correction on muscle activation amplitudes recorded from the cervicobrachial region

In clinical practice, postural correction is a common treatment approach for individuals with neck and shoulder pain. As chronic static muscle use is thought to be associated with the onset of some neck and shoulder pain syndromes, it is important to understand the impact a postural correction program might have on muscle activation amplitudes in the neck and shoulder regions. Normalized surface electromyographic data were recorded from the levator scapulae, upper trapezius, supraspinatus, posterior deltoid, masseter, rhomboid major, cervical erector spinae, and sternocleidomastoid muscles of the dominant side of each of eighteen healthy subjects. Subjects performed five repetitions of each of four seated typing postures (habitual, corrected, head-forward and slouched) and four standing postures (habitual, corrected, and head-forward and slouched). Repeated-measures analysis of variance models (alpha=0.05) revealed that in sitting postural correction tended to decreased the level of muscle activation required in all muscles studied during seated computer work, however this finding was not statistically significant. Corrected posture in sitting did, however produce a statistically significant reduction in muscle activity compared to forward head posture. Corrected posture in standing required more muscle activity than habitual or forward head posture in the majority of cervicobrachial and jaw muscles, suggesting that a graduated approach to postural correction exercises might be required in order to train the muscles to appropriately withstand the requirements of the task. A surprising finding was that muscle activity levels and postural changes had the largest impact on the masseter muscle, which demonstrated activation levels in the order of 20% maximum voluntary electrical activation.