Interobserver reliability of neck-mobility measurement by means of the flock-of-birds electromagnetic tracking system

Hybrid maneuver for benign paroxysmal positional vertigo in individuals with limited neck mobility: Case series

INTRODUCTION

Mobility limitation of the cervical spine compromises the adequate execution of the canalith repositioning maneuver (CRM) in cases of posterior semicircular canal benign paroxysmal positional vertigo (PSC-BPPV-GEO). Thus, novel therapeutic options are required for such individuals.

OBJECTIVES

This study describes the effects of a change in the biomechanical position for the execution of the CRM on symptoms of dizziness and mobility limitation regarding flexion-extension of the cervical spine in older people with unilateral PSC-BPPV-GEO.

METHODS

A quasi-experimental viability study was conducted with 15 older adults (11 women; mean age: 72.2 ± 8.1 years). Treatment consisted of a hybrid CRM. The participants were evaluated before and after the intervention using the modified Dix & Hallpike test, Dizziness Handicap Inventory (DHI) and a visual analog scale (VAS) for vertigo.

RESULTS

The modified Dix & Hallpike test was negative in all cases after the execution of the hybrid CRM. A significant reduction was found for dizziness measured using the DHI (mean difference: -39.3 ± 9.4, p < 0.001) and VAS (mean difference: -2.9 ± 0.8, p = 0.04) after the intervention.

CONCLUSION

The hybrid CRM proved executable and satisfactory for resolving symptoms of dizziness in older adults with PSC-BPPV. The present findings are promising and randomized controlled clinical trials should be conducted to evaluate the effectiveness of the hybrid CRM in this population.

A photogrammetric method for the measurement of three-dimensional cervical range of motion

Cervical spondylosis has gradually become a high-incidence disease in today's society. The cervical range of motion (CROM) is widely used as the evaluation criterion of cervical status, whereas the existing methods of CROM measuring are not humanized enough. Consequently, the purpose of this study was to develop a novel photogrammetric method to assess three-dimensional CROM. Three smartphone cameras were controlled to simultaneously capture three-direction photographs of the subject wearing the special designed device with three mark lines. The obtained photographs were uploaded to PC and the mark lines in each photograph were extracted by utilizing both the Radon transform and the Hough transform. By calculating and combining the tilt angles of three mark lines, the CROM of subject was indirectly determined. The performance of our method was compared with the goniometer-based method: the inter-instrument reliability was excellent for all six cervical movements with intraclass correlation coefficients>0.99; the degree of agreement between the two methods was high with Pearson's coefficients>0.98; and the Bland-Altman plots also revealed the validity of our method. Moreover, the concept of cervical motion curve was put forward to describe the movement track of neck in order to reflect the cervical health status. The proposed approach is feasible, automatic and convenient for the measurement of CROM and the generated cervical motion curve can intuitively exhibit the trajectory of neck. This technique that can easily acquire the biomedical information of cervical spine has tremendous potential in the diagnosis, healthcare and wellness management of neck.

Smartphone Applications as a Suitable Alternative to CROM Device and Inclinometers in Assessing the Cervical Range of Motion in Patients With Nonspecific Neck Pain

Objective

The purpose of this study was to compare the reliabilities of the cervical range-of-motion (CROM) device and a dual digital inclinometer (as accepted clinical tools) and iPhone or Android smartphone applications (clinometer and compass; as new technologies) in measuring cervical range of motion in patients with neck pain.

Methods

Twenty participants (13 women, 7 men; age 19-33 years) with neck pain persisting for at least 4 weeks were enrolled. Neck movements were measured in each participant using 4 noninvasive devices in random order.

Results

The CROM device showed excellent intra- and interrater reliabilities in assessing cervical range of motion except in right rotation for which it showed moderate intrarater reliability. The dual digital inclinometer demonstrated moderate to excellent intra- and interrater reliabilities. Cervical range of motion measurements using iPhone applications showed good to excellent intra- and interrater reliabilities, whereas Android applications had poor to excellent intra- and interrater reliabilities. Based on the validity results, all assessment tools differed from the CROM device depending on the direction of movement, although the iPhone applications showed fewer differences than the other 2 devices.

Conclusion

Generally, the CROM device showed the highest reproducibility, and iPhone applications showed more acceptable intra- and interrater reliabilities than the digital inclinometer and Android applications. The clinometer application of smartphones could be reliable in measuring frontal and sagittal cervical range of motion in patients with neck pain and in a sitting position. However, the compass application of the iPhone showed acceptable results, whereas that of the Android device could not be recommended for clinical use.

Paths of the cervical instantaneous axis of rotation during active movements-patterns and reliability

The instantaneous helical axis (IHA) is a characteristic of neck movement that is very sensitive to changes in coordination and that has potential in the assessment of functional alterations. For its application in the clinical setting, normative patterns must be available, and its reliability must be established. The purpose of this work is to describe the continuous paths of the IHA during cyclic movements of flexion-extension (FE), lateral bending (LB), and axial rotation (AR) and to quantify their reliability. Fifteen healthy volunteers participated in the study; two repetitions were made on the same day (by different operators) and over an 8-day interval (by the same operator) to evaluate the inter-operator and inter-session reliability, respectively. The paths described by the IHA suggest a sequential movement of the vertebrae in the FE movement, with a large vertical displacement (mean, 10 cm). The IHA displacement in LB and AR movements are smaller. The paths described by the IHAs have a very high reliability for FE movement, although it is somewhat lower for LB and RA movements. The standard error of measurement (SEM) is less than 0.5 cm. These results show that the paths of the IHA are reliable enough to evaluate changes in the coordination of intervertebral movement. Graphical abstract A video photogrammetry system is used to record the cyclic movements of the neck, from which the continuous trajectories of the associated instantaneous helical axis (IHA) are calculated. We have analyzed the movements of flexion-extension (FE), lateral flexion (LB), and axial rotation (AR) for a sample of 15 healthy subjects. The measurements have been repeated with two different operators (in the same session) and in two separate sessions (same operator). IHA displacement patterns have been obtained in each movement, and the reliability of the measurement of such IHA trajectories has been estimated.

Intra-rater and inter-rater reliability of cervical active range of movement in young asymptomatic adults using inertial sensors

Objectives: Current literature is scarce about the use of an inertial sensor to measure cervical active range of motion (aROM). The objective of the present study is to determine inter- and intra-reliability in the measurement of cervical aROM using inertial sensors in asymptomatic individuals.Materials and methods: Twenty asymptomatic individuals participated in the study. Two different physiotherapists measured each participant for cervical aROM (6 movements). The sequence of movements and the explanations given were standardized. The rater's order of measurement was randomized.Results: For the intra-rater results, the intraclass correlation coefficient (ICC) values for all cervical movements were good for Rater A (ICC >0.90) and Rater B (ICC >0.90). For the inter-rater results, the ICC values were above 0.75 for all movements, indicating a good level of reliability. Also, values obtained in SEM, MDC₉₀ and LOA indicate good agreement.Conclusion: The data obtained in this study suggest that inertial sensors can be used in clinics due to their high intra- and inter-rater ICC (>0.80). Also, its low economic cost, easy handling, and various utilities make this tool a useful alternative in the measurement of cervical aROM.

Cervical Spine Assessment Using Passive and Active Mobilization Recorded Through an Optical Motion Capture

OBJECTIVE

The purpose of this study was to develop and measure a protocol for evaluation of cervical range of motion (ROM), based on passive mobilization (PM) combined with active mobilization (AM) and recorded through an optical motion capture system.

METHODS

Passive and active mobilization were applied to 24 asymptomatic participants. Cervical ROM was recorded in 3 anatomic planes (transversal, frontal, and sagittal) using a precision optical system and a set of rigid bodies placed on the sacrum, spinous processes of the C7-T1 vertebrae, and the head. Three captures were made for each participant, distributed over 2 days. The characteristics of the PM, the interaction with the AM, and the coherence patterns between tests were analyzed. Reliability was studied for these procedures.

RESULTS

The reliability results of the PM were high in all analyzed indices; only flexion showed low values. Reliability of AM was greater than PM for flexion, extension, and lateralization because of the similarity to rotation. No statistically significant differences were found comparing PM and AM techniques.

CONCLUSION

The authors present a cervical ROM assessment based on combined PM and AM protocols at different sessions. This model demonstrated high reliability, individually and combined, and no differences were detected between PM and AM ROMs. Because the evaluator, instrumentation, and the patient are factors that could influence outcomes, the authors suggest that they be combined in protocols. These protocols could be used to evaluate the functional and structural capacity of patients and inform clinical outcomes.

Concurrent validity and interrater reliability of a new smartphone application to assess 3D active cervical range of motion in patients with neck pain

BACKGROUND

There is a lack of valid, reliable, and feasible instruments for measuring planar active cervical range of motion (aCROM) and associated 3D coupling motions in patients with neck pain. Smartphones have advanced sensors and appear to be suitable for these measurements.

OBJECTIVES

To estimate the concurrent validity and interrater reliability of a new iPhone application for assessing planar aCROM and associated 3D coupling motions in patients with neck pain, using an electromagnetic tracking device as a reference test.

DESIGN

Cross-sectional study.

METHODS

Two samples of neck pain patients were recruited; 30 patients for the validity study and 26 patients for the reliability study. Validity was estimated using intraclass correlation coefficients (ICCs), and by calculating 95% limits of agreement (LoA). To estimate interrater reliability, ICCs were calculated. Cervical 3D coupling motions were analyzed by calculating the cross-correlation coefficients and ratio between the main motions and coupled motions for both instruments.

RESULTS

ICCs for concurrent validity and interrater reliability ranged from 0.90 to 0.99. The width of the 95% LoA ranged from about 5° for right lateral bending to 11° for total rotation. No significant differences were found between both devices for associated coupling motion analysis.

CONCLUSIONS

The iPhone application appears to be a useful discriminative tool for the measurement of planar aCROM and associated coupling motions in patients with neck pain. It fulfills the need for a valid, reliable, and feasible instrument in clinical practice and research. Therapists and researchers should consider measurement error when interpreting scores.

Assessment of cervical range of motion in patients after axis fracture

BACKGROUND

Surgical treatment of odontoid fractures with posterior C1/C2 fusion always leads to severe limitations in mobility of the cervical spine and head.

PURPOSE

To assess the mobility of the cervical spine in patients treated with various surgical methods after an axis body fracture.

MATERIAL AND METHODS

A group of 61 subjects receiving surgical treatment in a group of 214 subjects treated for odontoid fractures at one ward of neurosurgery at a regional hospital. Studies also included odontoid peg and Hangman fractures. The range of motion of the head was compared to standards by the International Standard Orthopedic Measurements (ISOM) and to head mobility in a control group of 80 healthy subjects without any pathologies or complaints associated with the cervical spine. Ranges of motion were measured with the CROM goniometre with regard to flexion, extension, right and left lateral flexion and right and left rotation. The functional status was evaluated with Neck Disability Index (NDI) standard questionnaires indicated for patients with cervical spine pain.

RESULTS

Except for flexion and extension, patients after odontoid fractures had a statistically significantly smaller range of motion of the cervical spine in all planes compared to the control group and ISOM standards.

CONCLUSIONS

Odontoid fractures lead to limitations in mobility of the cervical spine even after treatment with methods that in theory should preserve the C1/C2 mobility.

Intrarater and Inter-rater Reliability of Active Cervical Range of Motion in Patients With Nonspecific Neck Pain Measured With Technological and Common Use Devices: A Systematic Review With Meta-regression

OBJECTIVES

The purpose of this systematic review was to compare intrarater and inter-rater reliability of active cervical range of motion (ACROM) measures obtained with technological devices to those assessed with low-cost devices in patients with nonspecific neck pain. As a secondary outcome, we investigated if ACROM reliability is influenced by the plane of the assessed movement.

METHODS

Medline, Scopus, Embase, the Cochrane Library, CINHAL, PEDro, and gray literature were searched until August 2016. Inclusion criteria were reliability design, population of adults with nonspecific neck pain, examiners of any level of experience, measures repeated at least twice, and statistical indexes on reliability. A device was considered inexpensive if it cost less than €500. The risk of bias of included studies was assessed by Quality Appraisal of Reliability Studies.

RESULTS

The search yielded 35 151 records. Nine studies met all eligibility criteria. Their Quality Appraisal of Reliability Studies mean score was 3.7 of 11. No significant effect of the type of device (inexpensive vs expensive) on intraclass correlation coefficient (ICC) was identified for intrarater (ICC = 0.93 vs 0.91; P > .99) and inter-rater reliability (ICC = 0.80 vs 0.87; P > .99). The plane of movement did not affect inter-rater reliability (P = .11). Significant influences were identified with intrarater reliability (P = .0001) of inexpensive devices, where intrarater reliability decreased (P = .01) in side bending, compared with flexion-extension.

CONCLUSIONS

The use of expensive devices to measure ACROM in adults with nonspecific neck pain does not seem to improve the reliability of the assessment. Side bending had a lower level of intrarater reliability.

Neck range of motion measurements using a new three-dimensional motion analysis system: validity and repeatability

PURPOSE

Neck movement is important for many activities of daily living (ADL). Neck disorders, such as cervical spondylosis and whiplash can limit neck movement and ADL. The cervical range of motion (CROM) device has been recently used to measure neck range of motion (ROM); however, this measurement includes trunk motion, and therefore does not represent a pure neck ROM measurement. The authors aimed to develop a new method to establish pure neck ROM measurements during flexion, extension, lateral bending, and rotation using a three-dimensional motion analysis system, VICON.

METHODS

Twelve healthy participants were recruited and neck ROMs during flexion, extension, lateral bending, and rotation were measured using VICON and the CROM device. Test-retest repeatability was assessed using interclass correlation coefficients (ICCs), standard error of measurement (SEM), and minimal detectable change (MDC). Validity between two measurements was evaluated using a determination coefficient and Pearson's correlation coefficient.

RESULTS

ICCs of neck ROM measured using VICON and the CROM device were all at substantial or almost perfect levels [VICON: ICC(1,2) = 0.786-0.962, the CROM device: ICC(1,2) = 0.736-0.950]. Both SEMs and MDCs were low in all measurement directions (VICON: SEM = 1.3°-4.5°, MDC = 3.6°-12.5°; the CROM device: SEM = 2.2°-3.9°, MDC = 6.1°-10.7°). Determination coefficients (R(2)s) and Pearson's correlation coefficients (rs) between the two measurement methods were high (R(2) = 0.607-0.745, r = 0.779-0.863).

CONCLUSIONS

VICON is a useful system to measure neck ROMs and evaluate the efficacy of interventions, such as surgery or physiotherapeutic exercise.

Differences in Human Cervical Spine Kinematics for Active and Passive Motions of Symptomatic and Asymptomatic Subject Groups

Most musculoskeletal disorders of the head and neck regions cannot be identified through imaging techniques; therefore clinician-conducted assessments (passive motions) are used to evaluate the functional ability of these regions. Although active motions do not require interaction with a clinician, these movements can also provide diagnostic indicators of dysfunction. The purpose of this research was to determine whether kinematic measures differed between active and passive movements of participants in symptomatic and asymptomatic groups. Data obtained on cervical lateral flexion range of motion (ROM), coupled axial rotation, and the angular velocity of lateral flexion were statistically analyzed and demonstrated differences between active and passive motions for symptomatic and asymptomatic subjects. Active motions had higher angular velocities (P< .001) and larger ROMs, with greater lateral flexions (P< .05). The asymptomatic group produced a larger average lateral flexion of 7.9° at an average angular velocity of 2 deg/s greater than the symptomatic group. Trends with regard to group assignment were the same for active and passive motions. This work demonstrates the potential for using kinematic measures of active and passive motions to develop an objective standard for diagnoses of cervical dysfunction and supports validity of the clinician-based analysis to distinguish between participant groups.

Influence of an eccentric load added at the back of the head on head-neck posture

A biomechanical study of the head-neck complex in seated subjects was conducted to verify whether a slight load, applied at the back of the head, could beneficially affect the head-neck posture, one of the factors of postural neck pain. An eccentric load of 0.5 kg was applied to the subjects' head by means of a special cap. A group of asymptomatic subjects (n=10, 28.9±12.1 yrs), and a group of subjects that had experienced mild, occasional neck pain (n=10, 39.6±18.4 yrs) were compared. They were analyzed while maintaining a still posture that was periodically perturbed to avoid habituation. A 3D motion analyzer and reflective markers placed over the head, the neck and the trunk, were used to compute head inclination and translation and head/neck flexion angle in different conditions: before, during and after having had the load applied for 15 min. Although the moment induced by the load was extensor, a forward-oriented movement of the head was observed in both groups. However, the forward displacement, in relation to the initial position, was smaller in the mild neck pain group than in the asymptomatic group (5.7±4.7 mm vs. 8.9±5.5 mm, P<0.05 and 2.6±5.9 mm vs. 11.0±9.0 mm after 15 min, P<0.05). After removing the load, the mild neck pain subjects assumed a retracted position (-3.8±2.7 mm) while the asymptomatic subjects stayed protracted (+3.5±5.1 mm, P<0.01). These unexpected findings suggest that a slight load added to the head can influence the postural control mechanisms and, in symptomatic subjects, lead to a new strategy aimed at a reduction of the neck extensor muscle contraction.

Changed cervical kinematics after fusion surgery

PURPOSE

Analyzing and comparing the range of motion and movement pattern of subjects who underwent an anterior cervical fusion using trabecular metal with control subjects.

METHODS

Three-dimensional kinematics of planar active axial rotation and active lateral bending of 50 experimental and 41 control subjects were registered by means of an electromagnetic tracking system.

RESULTS

Comparing the experimental group with the control group reveals that the range of the main motion component differs significantly (p < 0.01) during the active axial rotation and lateral bending movement. During active axial rotation, the coupled lateral bending motion component also differs between both groups. The root mean square value of the jerkiness (derivative of the acceleration) and de deviation from the 6-polynomial smoothed function of the main as well as the coupled motion component express the qualitative aspects of kinematics and are significantly different between the experimental and the control group for both movements (p < 0.05).

CONCLUSIONS

Subjects who have an anterior cervical fusion with trabecular metal show significant quantitative as well as qualitative differences in cervical kinematics during active axial rotation and lateral bending compared to control subjects.

Reproducibility of the cervical range of motion (CROM) device for individuals with sub-acute whiplash associated disorders

PURPOSE

The objective of this study was to evaluate the reproducibility of the cervical range of motion device when measuring both active and passive range of motion in a group of individuals with sub-acute Whiplash Associated Disorders (WAD).

METHODS

Participants were recruited as part of a large multi-centre Randomised Controlled Trial from UK emergency departments. Experienced research physiotherapists measured active and passive cervical spine movements in all directions. Both intra- and inter-observer reliability and agreement were assessed using the intra-class correlation coefficient, standard error of measurement and limits of agreement methods.

RESULTS

Different groups of 39 and 19 subjects were included in the intra and inter-observer studies, respectively. The CROM device demonstrated substantial intra- and inter-observer reliability and agreement for all the active and passive half-cycle movements (ICC range 0.82-0.99) with the exception of one (passive right lateral flexion for inter-observer; ICC 0.77).

CONCLUSIONS

The CROM device has proven to be a reproducible measurement method for a symptomatic WAD population using the measurement protocol described and can be used with confidence to differentiate individuals according to a single measurement.

Influence of number of operated levels and postoperative time on active range of motion following anterior cervical decompression and fusion procedures

STUDY DESIGN

A cohort study analyzing the cervical range of motion of subjects with anterior cervical decompression and fusion operation (ACDF).

OBJECTIVE

The purpose of this study was to compare the cervical range of motion of subjects who underwent an ACDF operation to age-matched healthy nonoperative subjects. Subjects were divided according to the number of operated levels, postoperative time point, and level of disability.

SUMMARY OF BACKGROUND DATA

ACDF is an operative treatment aimed at expansion of the spinal canal and relief of cord compression. In addition to alleviating pain, 2 common tools are used to measure postoperative success; cervical range of motion kinematic analysis and subjective evaluation questionnaires (Neck Disability Index [NDI]).

METHODS

This study involved 25 preoperative and 110 postoperative ACDF subjects as well as 18 control volunteers with no prior history of neck complaints. ACDF subjects were divided according to the number of operated levels; 1-, 2-, 3-, and 4-levels as well as time of their clinical visit; preoperative, early, and late postoperative. Before kinematic testing, the subjects were asked to complete the NDI survey. A virtual reality assisted electromagnetic tracking was used to measure an active voluntary motion of the head relative to the torso. The subjects' maximum range of motion was calculated and compared as they executed 3 to 5 consecutive cycles of the primary motions, flexion/extension, axial rotation, and lateral bending. An analysis of variance statistical test (P < 0.01) was used to determine significant differences between study groups. RESULTS.: Subject's range of motion decreased relative to control as the number of operated levels increased. Moreover, 1- and 2-level subjects increased their range motion relative to preoperative. Finally, there was a decrease in range of motion as the subject's level of disability increased as measured by an NDI score but all subjects reported a lower score relative to preoperative time point.

CONCLUSION

The active range of motion of subjects who underwent an ACDF surgery increased postoperative and was dependent on the number of operated levels. In addition, there was an improvement in the disability level after the surgery as measured by the NDI score.

Quantifying the effect of age on passive range of motion of the cervical spine in healthy working-age women

STUDY DESIGN

Cross-sectional study.

OBJECTIVES

To assess age-related changes and determine reference values for passive range of motion of the cervical spine in healthy women of working age.

BACKGROUND

Although cervical mobility is age dependent, the amount in which aging affects passive range of motion has not been previously reported. It is clinically important to know the effect of normal aging process on cervical motion to be able to separate and evaluate the possible effect of pathological processes.

METHODS AND MEASURES

Two hundred twenty healthy women, aged 20 to 59 years, participated in the study. Passive range of motion of the cervical spine in flexion, extension, lateral flexion, and axial rotation was measured with the Cervical Measurement System. Measurements to calculate intrarater reliability were obtained on 22 subjects.

RESULTS

Passive range of motion of the cervical spine diminished linearly with increasing age in all measured movement planes (P<.001 for all movements except for flexion which was P = .018). Mean body mass index adjusted reduction in passive range of motion was 0.5 degrees per 1-year increase in age. Intraclass correlation coefficients for intrarater reliability ranged from 0.79 to 0.92.

CONCLUSION

A gradual age-related reduction in passive cervical range of motion was observed in women of working age.

Cervical motion assessment using virtual reality

STUDY DESIGN

Repeated measures of cervical motion in asymptomatic subjects.

OBJECTIVES

To introduce a virtual reality (VR)-based assessment of cervical range of motion (ROM); to establish inter and intratester reliability of the VR-based assessment in comparison with conventional assessment in asymptomatic individuals; and to evaluate the effect of a single VR session on cervical ROM.

SUMMARY OF BACKGROUND DATA

Cervical ROM and clinical issues related to neck pain is frequently studied. A wide variety of methods is available for evaluation of cervical motion. To date, most methods rely on voluntary responses to an assessor's instructions. However, in day-to-day life, head movement is generally an involuntary response to multiple stimuli. Therefore, there is a need for a more functional assessment method, using sensory stimuli to elicit spontaneous neck motion. VR attributes may provide a methodology for achieving this goal.

METHODS

A novel method was developed for cervical motion assessment utilizing an electromagnetic tracking system and a VR game scenario displayed via a head mounted device. Thirty asymptomatic participants were assessed by both conventional and VR-based methods. Inter and intratester repeatability analyses were performed. The effect of a single VR session on ROM was evaluated.

RESULTS

Both assessments showed non-biased results between tests and between testers (P > 0.1). Full-cycle repeatability coefficients ranged between 15.0 degrees and 29.2 degrees with smaller values for rotation and for the VR assessment. A single VR session significantly increased ROM, with largest effect found in the rotation direction.

CONCLUSION

Inter and intratester reliability was supported for both the VR-based and the conventional methods. Results suggest better repeatability for the VR method, with rotation being more precise than flexion/extension. A single VR session was found to be effective in increasing cervical motion, possibly due to its motivating effect.

Three-dimensional analysis of cervical spine motion: reliability of a computer assisted magnetic tracking device compared to inclinometer

We aimed to investigate the reliability and reproducibility of a magnetic tracking technique for the assessment of overall cervical spine motion (principal and coupled movements). Ten asymptomatic male volunteers with a mean age of 29.3 years (range 20-37 years) were included in the study. Flexion, extension, left and right lateral bending and left and right axial rotation were measured using a magnetic tracking device (MTD) mounted onto a custom head-piece. For rotational movements in the frontal and sagittal planes the results were compared with the measurements of two standard inclinometers. Intra-observer, inter-observer and intra-instrument reliability was assessed with the intraclass correlation coefficient method. There were no significant differences for all motion measurements between the MTD and the inclinometer. High inter-observer reliability was found in flexion, extension, axial rotation and lateral bending indicating that the testing routine is applicable for different examiners. The intra-observer variability was high in flexion and extension, whereas in lateral bending the reliability coefficients were lower and displayed a fair to good reliability for most of the measurements with the MTD. The results of the MTD were found to be highly comparable with the inclinometer results with an inter-instrument correlation coefficient ranging from 0.88 to 0.99. The MTD is a reliable, reproducible method for three-dimensional motion analysis of the cervical spine and therefore a valuable method both for the clinical assessment of various degenerative and traumatic disorders and as a supplement of different therapeutic procedures and rehabilitation.

Assessment of the cervical range of motion over time, differences between results of the Flock of Birds and the EDI-320: A comparison between an electromagnetic tracking system and an electronic inclinometer

The objective of this study was to analyse cervical range of motion, assessed over time by means of a digital inclinometer (EDI-320) and a three-dimensional electromagnetic tracking device (Flock of Birds). The maximum active cervical range of motion was assessed with two measurement devices in three sessions over time, with 6-week intervals. In total, 26 women and 24 men (mean age: 44.4, SD: 9.9) without known pathology of the cervical spine participated. Four movements were measured axial rotation with the cervical spine in a flexed and in an extended position, flexion-extension, and lateral bending. The results showed that the factor time was significant for rotation in extension and rotation in flexion. The factor device was significant for all movements measured, and the interaction term between time and device was significant for all movements except rotation in extension. The Flock of Birds measured significantly higher ranges of motion on all motions except for lateral bending. A substantial variation in cervical range of motion was observed over time (ranging from -5.6 to 8.1) as well as between devices (ranging from -13.1 to 29.9). Substantial and significant differences in cervical range of motion were found over time as well as differences between the Flock of Birds and the EDI-320.

Clinimetric evaluation of active range of motion measures in patients with non-specific neck pain: a systematic review

The study is to provide a critical analysis of the research literature on clinimetric properties of instruments that can be used in daily practice to measure active cervical range of motion (ACROM) in patients with non-specific neck pain. A computerized literature search was performed in Medline, Cinahl and Embase from 1982 to January 2007. Two reviewers independently assessed the clinimetric properties of identified instruments using a criteria list. The search identified a total of 33 studies, investigating three different types of measurement instruments to determine ACROM. These instruments were: (1) different types of goniometers/inclinometers, (2) visual estimation, and (3) tape measurements. Intra- and inter-observer reliability was demonstrated for the cervical range of motion instrument (CROM), Cybex electronic digital instrument (EDI-320) and a single inclinometer. The presence of agreement was assessed for the EDI-320 and a single inclinometer. The CROM received a positive rating for construct validity. When clinical acceptability is taken into account both the CROM and the single inclinometer can be considered appropriate instruments for measuring the active range of motion in patients with non-specific neck pain in daily practice. Reliability is the aspect most frequently evaluated. Agreement, validity and responsiveness are documented less frequently.

Cervical motion in patients with chronic disorders of the cervical spine: a reproducibility study

STUDY DESIGN

Test-retest of cervical motion in patients with chronic disorders of the cervical spine.

OBJECTIVES

To determine the reproducibility of cervical motion and examine the feasibility of its representation by a single parameter.

SUMMARY OF BACKGROUND DATA

Reproducibility of cervical motion findings has been largely limited to normal subjects, leaving a conspicuous void regarding the measurement error in clinical groups.

METHODS

There were 2 groups of 25 chronic patients with whiplash and degenerative changes of the cervical spine tested twice (4-7 days). Head movement was measured along the 6 directions, as well as during rotation out of flexion and extension (cervical degenerative changes only).

RESULTS

Compared to normal subjects, both groups had a 25% to 35% reduction in cervical motion. High intraclass correlation coefficients (ICCs) (range 0.8-0.92) were derived for all directions. The ICCs for rotation out of flexion and extension were low. The relative standard error of measurement ranged from 15% to 28% for all directions, whereas the corresponding scores of the total cervical motion excursion were 10.6 (cervical degenerative changes) and 13.6% (whiplash).

CONCLUSIONS

Judged by the ICCs cervical motion, findings were reproducible. However, in view of the measurement error as well as the homogenous reductions, total cervical range of motion should be considered a suitable parameter for interpretation of cervical motion limitations in these patients.