Noninvasive three-dimensional analysis of cervical spine motion in normal subjects in relation to age and sex. An experimental examination

Pediatric and adult three-dimensional cervical spine kinematics: effect of age and sex through overall motion

STUDY DESIGN

Cross-sectional study.

OBJECTIVE

To determine the effect of age and sex on the three-dimensional kinematics of the cervical spine.

SUMMARY OF BACKGROUND DATA

Spine kinematics information has important implications for biomechanical model development, anthropomorphic test device development, injury prevention, surgical treatment, and safety equipment design. There is a paucity of data of this type available for children, and it is unknown whether cervical spine kinematics of the pediatric population is different than that of adults. The helical axis of motion (HAM) of the spine provides unique information about the quantity and quality (coupling etc.) of the measured motion.

METHODS

Ninety subjects were recruited and divided into 6 groups based on sex and age (young children aged 4-10 years, older children aged 11-17 years, adults aged 25+ years). Subjects actively moved their head in axial rotation, lateral bending, and flexion/extension. An optoelectronic motion analysis system recorded the position of infrared markers placed on the first thoracic vertebrae (T1) and on tight-fitting headgear worn by the subjects. HAM parameters were calculated for the head motion with respect to T1.

RESULTS

HAM location in axial rotation and flexion/extension was more anterior in young females compared to adult females. Young females had a more anterior HAM location in flexion/extension compared to young males, indicating an effect of sex. For females, the HAM locations of adults were superior to those of children in flexion/extension and lateral bending whereas in males the HAM locations of adults were inferior to those of children. Age-related differences in HAM orientation were also observed in axial rotation and lateral bending. CONCLUSION.: Cervical spine kinematics vary with age and sex. The variation in spine mechanics based on age and sex found in the present study may indicate general trends that would grow stronger in even younger children (age <4 years).

Cervical spinal disc replacement

Cervical spinal disc replacement is used in the management of degenerative cervical disc disease in an attempt to preserve cervical spinal movement and to prevent adjacent disc overload and subsequent degeneration. A large number of patients have undergone cervical spinal disc replacement, but the effectiveness of these implants is still uncertain. In most instances, degenerative change at adjacent levels represents the physiological progression of the natural history of the arthritic disc, and is unrelated to the surgeon. Complications of cervical disc replacement include loss of movement from periprosthetic ankylosis and ossification, neurological deficit, loosening and failure of the device, and worsening of any cervical kyphosis. Strict selection criteria and adherence to scientific evidence are necessary. Only prospective, randomised clinical trials with long-term follow-up will establish any real advantage of cervical spinal disc replacement over fusion.

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.

Mid- to long-term outcome of instrumented anterior cervical fusion for subaxial injuries

The management of patients with subaxial cervical injuries lacks consensus, particularly in regard to the decision which surgical approach or combination of approaches to use and which approach yields the best clinical outcome in the distinct injury. The trauma literature is replete with reports of surgical techniques, complications and gross outcome assessment in heterogeneous samples. However, data on functional and clinical outcome using validated outcome measures are scanty. Therefore, the authors performed a study on plated anterior cervical decompression and fusion for unstable subaxial injuries with focus on clinical outcome. For the purpose of a strongly homogenous subgroup of patients with subaxial injuries without spinal cord injuries, robust criteria were applied that were fulfilled by 28 patients out of an original series of 131 subaxial injuries. Twenty-six patients subjected to 1- and 2-level fusions without having spinal cord injury could be surveyed after a mean of 5.5 years (range 16-128 months). The cervical spine injury severity score averaged 9.6. Cross-sectional outcome assessment included validated outcome measures (Neck pain disability index, Cervical Spine Outcome Questionnaire, SF-36), the investigation of construct failure and successful surgical outcome were defined by strict criteria, the reconstruction and maintenance of local and total cervical lordosis, adjacent-segment degeneration and intervertebral motion, and the fusion-rate using an interobserver assessment. Self-rated clinical outcome was excellent or good in 81% of patients and moderate or poor in 19% that corresponded to the results of the validated outcome measures. Results of the NPDI averaged 12.4 +/- 12.7% (0-40). With the SF-36 mean physical and mental component summary scores were 47.0 +/- 9.8 (18.2-59.3) and 52.2 +/- 12.4 (14.6-75.3), respectively. Using merely non-constrained plates, construct failure was observed in 31% of cases and loss of local lordosis, expressed as a mean injury angle of 14 degrees, postoperative angle of -5.5 degrees and follow-up angle of -1 degree, was significant. However, total cervical lordosis was within the limits of normalcy (-24.3 degrees +/- 13.3) and fusion-rate was 88.5%. The progression of adjacent-level degeneration was shown to be significantly influenced by a decreased plate-to-disc-distance. Adjacent-level intervertebral motion was not altered due to the adjacent fusion, but reduced in the presence of advanced adjacent-level degeneration. Patients were more likely to maintain a high satisfaction level if they succeeded to maintain segmental lordosis (<0 degree), had a solid fusion, an increased plate-to-disc distance, and if they were judged to have a successful surgical outcome that included the absence of construct failure and reconstruction of lordosis within +/-1 SD of normalcy. Using validated outcome vehicles the interdependencies between radiographical, functional and clinical outcome parameters could be substantiated with statistically significant correlations. The use of validated outcome vehicles in a subgroup of patients with plated anterior cervical fusions for subaxial injuries is recommended. With future studies, it enables objective comparison of surgical techniques and related radiographical, functional and clinical outcome.

Cervical range of movement in relation to neck dimension

The authors investigated the effect of neck dimension upon cervical range of motion. Data relating to 100 healthy subjects, aged between 20 and 40 years, were recorded with respect to age, gender and range of motion in three planes. Additionally, two widely used methods of measuring neck motion, chin-sternal distance and uniplanar goniometer, were assessed against a validated measurement tool, the 'CROM goniometer'. Using multiple linear regression analysis it was determined that sagittal flexion (P = 0.002) and lateral rotation (P < 0.0001) were most closely related to neck circumference alone whereas lateral flexion (P < 0.0001) was most closely related to a ratio of circumference and length of neck. Hence, assessing cervical range of motion as outcome variable or as a measure at posttreatment follow-up, neck circumference was shown to be one of the factors influencing total neck motion, particularly sagittal flexion and lateral tilt. Comparison of cervical range of motion assessed with a validated measurement tool, the CROM goniometer, with results of both frequently applied clinician's instruments, the uniplanar goniometer and measurement of chin-sternal distance, showed low reliability with the latter techniques, and motion values measured with these techniques should be interpreted with caution if using them for comparison of cervical range of motion of alike groups. We demonstrated that neck dimension should be incorporated into cervical functional outcome assessment and one should be wary about recorded values for neck motion from non-validated measurement tools.

Effects of age and gender on the movement workspace of the trapeziometacarpal joint

While researchers have suggested that joint mobility would probably be affected by age and gender, research findings often present discrepancies. Little research has been performed on the factors which effect mobility of the trapeziometacarpal (TMC) joint. The purpose of this study was to address the effects of age and gender on the ranges of motion of the normal TMC joint. Eighty normal subjects divided into four age groups participated in this study. The TMC joint motions were recorded using an electromagnetic tracking system. In order to achieve a maximal range of TMC joint motion which was defined as the maximal workspace, each subject was asked to perform actively maximal circumduction, flexion-extension, and abduction-adduction of the TMC joint. Numerical and statistical methods were used to compute the TMC workspace and to detect significant differences. A workspace-to-length ratio was determined as an index to examine the effects of the age and gender on the joint mobility. The results demonstrated that age and gender had significant influences on the TMC workspace among the groups studied. The understanding of TMC joint mobility under different age and gender conditions is achieved through this study. The findings can be used to report clinical measures in the determination of the extent of impairment of osteoarthritis as well as the outcomes between pre- and post-surgical (or non-surgical) interventions.

Influence of scapular position on cervical rotation range of motion

STUDY DESIGN

Cross-sectional study, quasi-experimental design.

OBJECTIVES

To compare the active cervical rotation range of motion (ROM) between healthy young subjects with a neutral vertical scapular alignment and subjects with scapular depression, and to examine the influence of modifying the vertical position of the scapulae on active cervical rotation ROM.

BACKGROUND

Altered scapular alignment is proposed to be related to neck dysfunction and pain. Changes in the alignment of either the scapulae or the cervical spine can potentially influence the biomechanics of the other by altering the tension at the cervicoscapular muscles.

METHODS AND MEASURES

Fifty-eight college age students with neutral vertical scapular alignment (NS group, n = 29) or depressed scapular alignment (DS group, n = 29) volunteered to participate in the study. Cervical rotation ROM was assessed using the CROM device in 2 conditions: condition 1, resting scapular position; condition 2, neutral vertical scapular position with forearms supported.

RESULTS

The ANOVA revealed no significant group-by-condition interaction (F = 0.19, df = 1, P = .66). There was a significant main effect of condition (F = 47.16, df = 1, P<.001). For both groups, there was an increase in cervical rotation ROM in condition 2 when compared to condition 1 (mean +/- SD, 10.2 degrees +/- 3.1 degrees; 95% Cl: 4.1 degrees to 16.4 degrees). There was no main effect of group (F = .41, df = 1, P = .53).

CONCLUSION

Our results suggest that in a young healthy population the vertical scapular alignment does not influence cervical rotation ROM. Supporting the upper limbs, however, results in a significant and similar increase in cervical rotation ROM for both groups.

The effects of the Mulligan Sustained Natural Apophyseal Glide (SNAG) mobilisation in the lumbar flexion range of asymptomatic subjects as measured by the Zebris CMS20 3-D motion analysis system

Background

Mulligan's mobilisation techniques are thought to increase the range of movement (ROM) in patients with low back pain. The primary aim of this study was to investigate the application of the Mulligan's Sustained Natural Apophyseal Glide (SNAG) technique on lumbar flexion ROM. The secondary aim was to measure the intra- and inter-day reliability of lumbar ROM employing the same procedure.

Methods

49 asymptomatic volunteers participated in this double-blinded study. Subjects were randomly assigned to receive either SNAG mobilisation (n = 25), or a sham mobilisation (n = 24). The SNAG technique was applied at the L₃and L₄ spinal levels with active flexion in sitting by an experienced manual therapist. Three sets of 10 repetitions at each of the two spinal levels were performed. The sham mobilisation was similar to the SNAG but did not apply the appropriate direction or force. Lumbar ROM was measured by a three dimensional electronic goniometer (Zebris CMS20), before and after each technique. For the reliability, five measurements in two different days (one week apart) were performed in 20 healthy subjects.

Results

When both interventions were compared, independent t tests yielded no statistically significant results in ROM between groups (p = 0.673). Furthermore no significant within group differences were observed: SNAG (p = 0.842), sham (p = 0.169). Intra- and inter-day reliability of flexion measurements was high (ICC_1,1 > 0.82, SEM < 4.0°, SDD<16.3%) indicating acceptable clinical applicability.

Conclusion

While the Zebris proved to be a reliable device for measuring lumbar flexion ROM, SNAG mobilisation did not demonstrate significant differences in flexion ROM when compared to sham mobilisation.

Trial registration

Current Controlled Trials NCT00678093.

Establishing reference values for cervical spine range of motion in pre-pubescent children

Medical professionals, physical therapists, product designers, and computational models all use cervical spine range of motion reference values. To support these functions, researchers have collected a plethora of data to determine the normal range of motion of the cervical spine of adult subjects. However, little to no data exists for subjects under the age of 14. This study utilized the cervical range of motion device, referenced with respect to the Frankfort Plane, to measure the active cervical spine range of motion in all three cardinal planes of the human body, for 106 subjects whose ages ranged from 8 to 10 years. The active range of motion for flexion, extension, lateral extension, and rotation was calculated as 66+/-13 degrees , 85+/-14 degrees , 58+/-8 degrees , and 77+/-7 degrees , respectively, using linear statistics. The observed data significantly differed from the published American Medical Association guidelines for adults but fell within the range of the reference values for 10 year olds. Stratifying and analyzing the range of motion data with respect to gender yielded no significant effect. Appendix A analyzes the data using angular statistics, and produces virtually identical results as those from linear statistics.

A distinct pattern of myofascial findings in patients after whiplash injury

OBJECTIVE

To identify objective clinical examinations for the diagnosis of whiplash syndrome, whereby we focused on trigger points.

DESIGN

A cross-sectional study with 1 measurement point.

SETTING

A quiet treatment room in a rehabilitation center.

PARTICIPANTS

Patients (n=124) and healthy subjects (n=24) participated in this study. Among the patient group were patients with whiplash-associated disorders (n=47), fibromyalgia (n=21), nontraumatic chronic cervical syndrome (n=17), and endogenous depression (n=15).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

Each patient and control subject had a manual examination for trigger points of the semispinalis capitis, trapezius pars descendens, levator scapulae, scalenus medius, sternocleidomastoideus, and masseter muscles bilaterally.

RESULTS

Forty (85.1%) of the patients with whiplash had positive trigger points in the semispinalis capitis muscle. The patients with whiplash had a significantly higher prevalence of positive trigger points in the semispinalis capitis muscle than any of the control groups (P<.05). For the other examined muscles, the prevalence of trigger points in the patients with whiplash did not differ significantly from the patients with fibromyalgia or nontraumatic chronic cervical syndrome. It did differ from the patients with endogenous depression and the healthy controls.

CONCLUSIONS

Patients with whiplash showed a distinct pattern of trigger point distribution that differed significantly from other patient groups and healthy subjects. The semispinalis capitis muscle was more frequently affected by trigger points in patients with whiplash, whereas other neck and shoulder muscles and the masseter muscle did not differentiate between patients with whiplash and patients with nontraumatic chronic cervical syndrome or fibromyalgia.

Quantification of the coupled motion that occurs with axial rotation and lateral bending of the head-neck complex: an experimental examination

The vertebrae of the cervical spine exhibit out-of-plane or coupled motion during axial rotation and lateral bending. Quantifying the range of motion (ROM) of this occurrence can aid the understanding of cervical spine injury mechanisms and disorders, as well as the development of new treatment methods. Previous studies have formulated ratios to describe coupled motion obtained from in-vitro examinations. The aim of the present study was to use in-vivo test data to develop mathematical relationships to quantify the coupled motion that occurs with axial rotation and lateral bending of the head-neck complex. Using a three-dimensional motion analyser it was possible to trace the coupling effect throughout the full range of unrestricted head-neck motion. Values for primary and coupled ROMs were obtained, showing no significant difference between male and female primary ROMs but a small disparity between male and female coupled ROMs. Regression equations were found to quantify coupled motion throughout the range of axial rotation and lateral bending. The present experimental study also examines the range of horizontally fixed axial rotation of the head to determine the minimum amount of coupled lateral bending that takes place, which has not been measured previously.

Manual fixation versus locking during upper cervical segmental mobilization

BACKGROUND

Three-dimensional kinematic aspects of coupled motion during manual cervical mobilization have not previously been studied. Using an in vitro 3D-motion analysis method, the kinematic effects of two different segmental techniques for axial rotation and lateral bending mobilization of the upper cervical spine were investigated as a second part of the study (in part one, kinematic effects of flexion-extension mobilization have been investigated).

METHODS

Axial rotation and lateral bending mobilization of the atlanto-occipital and atlanto-axial segments were analysed in vitro using an electromagnetic tracking device. Local reference frames were defined based on bony reference points that were registered using a 3D-digitizing stylus. Five embalmed and one fresh specimen were analysed. Segmental motion was registered simultaneously in the atlanto-occipital and the atlanto-axial joints during manual mobilization through the full range of axial rotation and lateral bending mobility. The 3D-kinematic aspects during regional mobilization were compared with those during segmental mobilization with manual fixation and during segmental mobilization using a locking technique.

RESULTS

During both segmental axial rotation techniques of the atlanto-axial joint, a significant reduction of the coupled lateral bending and flexion-extension motion was observed. The locking technique also induced an increase in the main axial rotation component. During lateral bending mobilization of the atlanto-axial joint, the manual fixation technique reduced the effect on the coupled flexion-extension component significantly.

INTERPRETATIONS

These results suggest that for manual segmental axial rotation and lateral bending mobilization of the upper cervical spine segmental manual fixation or locking may be preferred in different situations depending on the desired effects. This study brings additional information to the data provided by part 1 of this study on the 3D-arthrokinematic effects of flexion-extension mobilization.

A method to measure cervical spine motion over extended periods of time

STUDY DESIGN

System validation study.

OBJECTIVE

To develop and validate a motion sensor system for measuring cervical spine motion over extended time periods.

SUMMARY OF BACKGROUND DATA

Many studies using different methodologies have tried to estimate cervical spine motion. These have mostly been carried out in a laboratory setting performing active/passive range of motion or activities of daily living. However, cervical spine performance over extended periods of time in natural environments remains unknown.

METHODS

A novel motion sensor system, Wisconsin Analysis of Spine Motion Performance (WASP), was validated using 2 benchmarks: a materials testing machine (MTS) and optical motion tracking laboratory. Parameters tested included drift, frequency response, accuracy, effect of sensor orientation, and coupled motions. Applied motions from the MTS and measured motions in subject volunteers under various conditions were compared with WASP using correlation coefficients. Intersubject and intrasubject variability analyses for WASP were also performed.

RESULTS

The average WASP slopes for accuracy (compared with MTS) in flexion-extension, lateral bending, and axial rotation were 0.89, 0.93, and 0.38, respectively. The correlation coefficient was 0.99 in all cases. Compared with optical motion tracking, the WASP regression slopes were 1.1, 1.02, and 0.4 and the correlation coefficients were 0.98, 0.92, and 0.93 in the 3 axes of motion. Coupled motion was noted during all subject motions. WASP peak detection algorithm had a 0% error discounting boundary conditions.

CONCLUSION

WASP was accurate in flexion-extension and lateral bending. In axial rotation, WASP was less accurate. However, the system was highly reliable with low intersubject and intrasubject variability. WASP can be used in estimating cervical spine motion with high reliability while keeping in mind the decreased accuracy in measuring axial rotation.

In vivo ultrasound real-time motion of the cervical spine during intubation under manual in-line stabilization: a comparison of intubation methods

BACKGROUND AND OBJECTIVE

In emergency trauma situations, manual in-line stabilization of the cervical spine is recommended to reduce cervical spine movement during intubation. The aim of this study was to compare the effect of manual in-line stabilization during different intubation techniques on three-dimensional cervical spine movements and times to intubation.

METHODS

Forty-eight subjects without any history of trauma, inflammatory or degenerative disorder of the cervical spine were randomly grouped, regardless of gender or age. All underwent elective surgery under general anaesthesia. Under manual in-line stabilization, laryngeal intubation with Macintosh laryngoscope, intubating laryngeal mask airway, fibre-endoscopic oral intubation and fibre-endoscopic nasal intubation was performed. During the intubation process, cervical three-dimensional motion was detected by an ultrasound real-time motion analysis system and intubation times were measured.

RESULTS

Cervical spine range in the extension/flexion direction of orolaryngeal intubation with Macintosh (17.57 +/- 8.23 degrees ) showed significantly more movement than using the intubating laryngeal mask airway (4.60 +/- 1.51 degrees ) and fibreoptic procedures. Intubating laryngeal mask airway was significantly different than the fibreoptic intubation techniques. There was also a significant difference between oral (3.61 +/- 2.25 degrees ) nasal and (5.88 +/- 3.11 degrees ) fibreoptic intubation. Times to intubation all differed significantly (P < 0.05) for the Macintosh laryngoscope (27.25 +/- 8.56 s) and for the intubating laryngeal mask airway (16.5 +/- 9.76 s). Fibreendoscopic laryngoscopic oral (52.91 +/- 56.27 s) and nasal (82.32 +/- 54.06 s) intubation resulted in further prolongation of the times to intubation.

CONCLUSIONS

The intubating laryngeal mask airway with manual in-line stabilization is a potentially useful adjunct to intubation of patients with potential cervical spine injury, if there are no contraindications to these methods. These results predict that fibreoptic procedures may be a safe instrument for airway management in patients with potential cervical spine injuries; however, the main disadvantages are the longer intubation times.

Reliability and Normative Database of the Zebris Cervical Range-of-Motion System in Healthy Controls with Preliminary Validation in a Group of Patients with Neck Pain

OBJECTIVE

The first aim of this study was to determine the reliability of the Zebris (Achen, Germany) ultrasound-based testing of cervical range of motion (ROM). The second aim was to develop a normative database in a healthy sample of 96 volunteers. The third aim was to evaluate, with the Zebris system, the ROM in a sample of patients with chronic neck pain compared to healthy controls to determine if cervical ROM could discriminate between these groups and between subgroups of pain patients (with or without whiplash injury).

METHODS

The study participants were 96 healthy volunteers, 14 patients with idiopathic neck pain, and 16 patients with chronic whiplash. Cervical ROM was measured in the 3 planes with the Zebris CMS 70P ultrasound-based motion analysis system. The intra- and interrater reliability of the protocol was tested in 12 volunteers.

RESULTS

Full-cycle measurements showed high reliability (intraclass correlation coefficient, 0.80-0.94) with the SE of measurement ranging from 4.25 degrees to 7.88 degrees. The distribution of ROM measures showed a great individual variation, with a significant age-related decrease in ROM in all directions. Range of motion was reduced in patients with chronic whiplash in all primary movements, compared to healthy subjects, whereas in patients with idiopathic neck pain, only rotation showed reduced ROM.

CONCLUSION

Results demonstrate a high degree of test-retest reliability in measuring cervical ROM. The use of normative data for ROM when evaluating patients with neck disorders needs to take age into account. The current study has demonstrated that patients with chronic neck pain demonstrate reduced ROM, which differs between patients with idiopathic neck pain and those with chronic whiplash.

Three-dimensional motion analysis of the lumbar spine during "free squat" weight lift training

BACKGROUND

Heavy weight lifting using a squat bar is a commonly used athletic training exercise. Previous in vivo motion studies have concentrated on lifting of everyday objects and not on the vastly increased loads that athletes subject themselves to when performing this exercise.

HYPOTHESIS

Athletes significantly alter their lumbar spinal motion when performing squat lifting at heavy weights.

STUDY DESIGN

Controlled laboratory study.

METHODS

Forty-eight athletes (28 men, 20 women) performed 6 lifts at 40% maximum, 4 lifts at 60% maximum, and 2 lifts at 80% maximum. The Zebris 3D motion analysis system was used to measure lumbar spine motion. Exercise was performed as a "free" squat and repeated with a weight lifting support belt. Data obtained were analyzed using SAS.

RESULTS

A significant decrease (P < .05) was seen in flexion in all groups studied when lifting at 40% maximum compared with lifting at 60% and 80% of maximum lift. Flexion from calibrated 0 point ranged from 24.7 degrees (40% group) to 6.8 degrees (80% group). A significant increase (P < .05) was seen in extension when lifting at 40% maximum was compared with lifting at 60% and 80% maximum lift. Extension from calibrated 0 point ranged from -1.5 degrees (40% group) to -20.3 degrees (80% group). No statistically significant difference was found between motion seen when exercise was performed as a free squat or when lifting using a support belt in any of the groups studied.

CONCLUSION

Weight lifting using a squat bar causes athletes to significantly hyperextend their lumbar spines at heavier weights. The use of a weight lifting support belt does not significantly alter spinal motion during lifting.

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.

Normal cervical spine range of motion in children 3-12 years old

STUDY DESIGN

This study measured active cervical spine range of motion (ROM) in children ages 3-12 years using 2 methodologies: (1) a cervical spine ROM instrument, and (2) a digital videography based technique.

OBJECTIVE

To determine the active cervical spine ROM, as defined by flexion/extension, lateral bending, and horizontal rotation, for children ages 3-12 years.

SUMMARY OF BACKGROUND DATA

Review of current literature reveals limited studies of cervical spine ROM in children, many of which do not provide data on children younger than 8 years of age when many of the structural changes of the cervical spine are thought to occur.

METHODS

A total of 67 children (39 girls) within 3 age groups, 3-5 years (26 children), 6-8 years (22), and 9-12 years (19), were tested in flexion/extension, lateral bending, and horizontal rotation. The subjects repeated the neck movements 3 times for each direction in each method (ROM instrument and videography), and the maximum ROM values were recorded. Within each age group, the mean, standard deviation, and range for each ROM was calculated, and ROM values from the 2 methods were compared. The effect of age and gender on ROM was assessed via analysis of variance.

RESULTS

For the ROM instrument, only flexion and right and left rotation were shown to increase with age (P < 0.05). This difference resulted in an increase in ROM of approximately 7 degrees between the youngest and oldest age group. No age effects were present in the videography data. No significant differences between the genders were detected for any of the ROM measures using either method (minimum P = 0.22). In general, the videography method resulted in higher values for flexion, extension, and rotation, and lower values for lateral bending. These differences were greater for the younger children.

CONCLUSIONS

This study contributes valuable normative data for pediatric cervical spine ROM in children that can be used as a clinical reference and for biomechanical applications. In children 3-12 years of age, both flexion and rotation increased slightly with age. Of interest, there were no differences in ROM with gender, which contradicts adult literature where females have been shown to have more cervical spine ROM than males.

The use of the Zebris motion analysis system for measuring cervical spine movements in vivo

The cervical spine exhibits the greatest range of motion among the spinal segments due to the complex interaction of its triplanar components of movement. As a result, measurement of movements of the cervical spine and of the various orthoses used in cervical spine injuries has proved difficult with no one method proving satisfactory. This paper uses the Zebris ultrasonic three-dimensional motion analysis system to measure flexion, extension, range of lateral bending, and range of axial rotation in five similar male and five similar female subjects with no history of neck injuries. The subjects were tested unrestrained and in soft and hard collars, as well as in Philadelphia, Miami J, and Minerva orthoses. Results show that the Minerva is the most stable construct for restriction of movement in all planes in both groups. Looking at these results allows ranking of the measured orthoses in order of their three-dimensional stability. Furthermore, by presenting reproducible data incorporating the composite triplanar movements of the cervical spine, thus allowing comparative analysis of the studied orthoses, they propose the Zebris as a reliable, repeatable, and safe method of measurement of cervical spine motion with low intersubject variability.

Test-retest reliability of cervicocephalic kinesthetic sensibility in three cardinal planes

The test-retest reliability of both the head-to-neutral head position (NHP) and head-to-target repositioning tests in three cardinal planes has been examined in this study. Twenty young adults underwent both head repositioning tests and retests with 10 min rest intervals. Root mean square error (RMSE, total error), constant error (CE, directional bias), variable error (VE, variability), and standard error of measurement (SEM) were calculated from the position data recorded by an ultrasound-based motion analysis system. Intra-class correlation coefficients (ICC) were used to examine reliability. The results showed fair to excellent reliability of RMSE during head-to-NHP (ICC=0.45-0.80) and head-to-target tests (ICC=0.42-0.90), except during the head-to-NHP test (ICC=0.29) from a head extended position. Low reliability of VE associated with the neck motion toward left side bending indicated a direction-dependent effect. The SEM of RMSE (0.7-2.6 degrees), CE (0.3-4.0 degrees) and VE (0.4-1.5 degrees) indicated an acceptable range of error. The present study indicated acceptable and reliable RMSE measurements with a motion analysis system in healthy young adults. Furthermore, examining the CE and VE could contribute to the interpretation of whether the subject performed the reposition tests with directional bias and repositioning variability, respectively.

Cervical spine ROM measurements: optimizing the testing protocol by using a 3D ultrasound-based motion analysis system

The aim of this study was to evaluate the intra- and inter-examiner reliability and validity of neck range of motion (ROM) measurements. Thirty-five healthy subjects were assessed in all neck movements from two initial positions, sitting and standing, actively (open and closed eyes) and passively by using a 3D ultrasound-based motion analysis device (Zebris). Three tests were employed to assess intra-examiner reliability and two examiners used for the inter-examiner reliability. X-rays in neck flexion and extension were used to validate the Zebris system. The standing position yielded higher intraclass correlation coefficient (ICC) values (>0.86) with less error [smallest detectable difference (SDD)<13.8%] than sitting (ICC>0.79, SDD<14%). Passive assessment of neck ROM presented better reproducibility than active assessment with open or closed eyes in both positions. The inter-examiner reliability was moderate (ICC=0.43-0.68). The correlation between the Zebris system and X-rays was high in both flexion and extension movements. The results showed that the most reliable protocol for assessment of neck ROM is a passive measurement in the standing position. The measurements were well validiated against X-rays and the experience of the investigators must be considered before any comparison among studies is employed.

Primary and coupled cervical movements: the effect of age, gender, and body mass index. A 3-dimensional movement analysis of a population without symptoms of neck disorders

STUDY DESIGN

Exploratory experimental design.

OBJECTIVES

To examine primary and coupled cervical movements, and to study the effects of age, gender, and body mass index in a "neck-healthy" population. These data could serve as a basis for future interventions and to assess normal variations.

SUMMARY OF BACKGROUND DATA

Cervical movements are biomechanically and neurophysiologically complex. Neck disorders and trauma most often influence cervical movements. With 3-dimensional recordings, it is possible to make precise, noninvasive evaluations of how the head moves on the stable trunk, and to analyze primary and coupled movements.

METHODS

A total of 120 subjects (60 men and 60 women, ages 20-79), were tested with Zebris (Zebris Medizintechnik GmbH, Isny, Germany), a 3-dimensional movement analyzer.

RESULTS

Age influences the majority of primary and coupled movements. With increasing age, primary movement size decreases in all cardinal planes. Age most strongly affects the coupled movements of primary rotation and lateral flexion. Gender and body mass index have only slight influences.

CONCLUSIONS

Coupled movements are a natural part of cervical motion together with primary movements and follow specific patterns in subjects with no symptoms of neck disorders. Our study shows that cervical motion alters throughout life according to specific patterns but with individual variations.

Performance of cervical motion in chronic whiplash patients and healthy subjects: the case of atypical patients

STUDY DESIGN

A comparative study of cervical motion performance in chronic whiplash (CW) patients and healthy subjects.

OBJECTIVES

To examine the efficiency of total cervical range of motion (TCROM), which consists of the combined score of all six primary movements and their mean coefficient of variation (MCV), in differentiating CW patients from healthy subjects as well as typical from atypical patients. Additionally to explore in the patients possible relationships between their cervical motion profile and functional and personality traits.

SUMMARY OF BACKGROUND DATA

Previous studies revealed that cervical motion was an efficient discriminator between healthy and CW patients. However, none of these studies provided either guidelines regarding cutoff scores or insight as to what should be considered typical compared with atypical patient with respect to cervical motion performance.

METHODS

Cervical motion was measured in 75 healthy subjects and 101 CW patients in each of the six primary movements. In addition, patients filled the functional neck disability index (NDI) and personality symptom check list (SCL-R-90) questionnaire.

RESULTS

Total CROM was significantly lower and the MCV was significantly higher in patients compared with healthy subjects. Age and gender affected TCROM significantly in both groups while MCV remained unaffected, respectively. Atypical patients were identified by having a TCROM < 58 degrees and or MCV > 22%, both scores corresponding to 2 SDs below and above group means, respectively. These benchmarks resulted in classifying as atypical 6% of the CW group who also scored drastically higher in the NDI and SCL-R-90 questioners.

CONCLUSIONS

Using MCV and TCROM adds new insight regarding what should be considered as atypical cervical motion profile in CW patients. Several aspects of this complex clinical entity are discussed.

Cervical joint position sense: an intra- and inter-examiner reliability study

OBJECTIVES

To evaluate the intra- and inter-examiner reliability of neck active joint position sense measurements in different head movements.

METHODS

Participants had to reproduce actively a specific angle-target in all movements (flexion, right/left rotation, right/left side flexion) from two initial positions, sitting and standing by using a 3D ultrasound-based motion analysis device. Three tests were employed to assess intra-examiner reliability and two examiners used for the inter-examiner reliability. Absolute error (AE) and variable error (VE) indices were used to assess the repositioning accuracy. Intraclass correlation coefficient (I.C.C.(1,1)), standard error of measurement (S.E.M.), smallest detectable difference (S.D.D.) indices were calculated for the analysis of the results.

RESULTS

Both AE and VE yielded poor to moderate I.C.C.s in any movement and position (-0.01 to 0.50 and 0.01-0.25, respectively). AE presented higher I.C.C.s estimates than the VE but the S.D.D.s were similar for both indices. Regarding the AE, the standing position yielded higher I.C.C. estimates (0.15-0.68) than the sitting position (-0.01 to 0.43) but the S.E.M. (1.2-3.0 degrees and 1.5-3.5 degrees, respectively) and S.D.D. values (123.3-191.8% and 139.9-203.8%, respectively) showed no specific trend in favour of any position. The VE reliability indices showed that standing position was more reliable with less error than sitting. The inter-examiner data showed similar results to the intra-examiner study.

CONCLUSIONS

The statistical analysis of the present experiments showed that the method employed for measuring cervical joint position sense is unreliable. However, it needs further research to identify the discriminatory power of these tests or if they are clinically unacceptable.

Analysis of head movements coupled with trunk drift in healthy subjects

Accelerometers were used to measure sequential head tilt and trunk drift in 14 healthy young subjects while they performed three kinds of head task. First, maximum inclination angles in anterior, posterior, right and left directions were measured to estimate cervical ranges of motion for flexion-extension and lateral bending. The inclination angles measured (61.2 degrees on average for flexion, 51.7 degrees for extension, 42.7 degrees for right bending and 43.9 degrees for left bending) were consistent with previous findings. Secondly, cross-correlation analysis was applied to evaluate the degree of functional coupling between the head and trunk during flexion-extension and lateral bending. Significantly higher correlation coefficients were found between head tilt and trunk drift when these movements were in the same (iso-) directional condition than in a different (allo-) directional condition. The coupled trunk drift in flexion-extension for the iso-directional condition (10.3 degrees on average) was much larger than for the allodirectional condition (2.3 degrees). Finally, head turning was recorded as oval traces in a biaxial plane. In both clockwise and counter-clockwise head turning conditions, the maximum inclination angles of the traces were larger in the anterior-posterior direction (59.8 degrees anterior and 58.2 degrees posterior, in the clockwise condition, and 47.4 degrees and 47.4 degrees in the counter-clockwise condition) than in the right-left direction (36.3 degrees right and 39.0 degrees left, in the clockwise condition, and 40.5 degrees and 36.7 degrees in the counter-clockwise condition), and the angles in the four directions were almost equal to flexion-extension and lateral bending. The characteristics of the traces recorded and a possible application of the present recording system are discussed.

Measurement of cervical range of motion pattern during cyclic neck movement by an ultrasound-based motion system

Goniometers and radiographic imaging have been used to measure active or passive cervical range of motion (ROM) in asymptomatic adults. However, the ultrasound-based coordinate measuring system (CMS) can measure continuous neck motion in three dimensions. The aims of this investigation are to evaluate the reliability and validity of ultrasound-based CMS (Zebris, CMS 70P), and to compare the cervical ROM patterns of asymptomatic young and middle-aged adults during continuous neck motions in the three cardinal planes. The ROM reciprocal ratio was defined as the ratio of the ROM from neutral position in one direction versus that in the opposite direction at the same cardinal plane. This study demonstrated the high test-retest reliability and validity of CMS during cervical motion in Chinese participants. Middle-aged adults exhibit reduced ROM ratios in the sagittal and frontal planes. The advantages and limitations of the CMS measurement tool and the potential future applications are documented. The measurement of neck motion pattern by ultrasound-based CMS may provide information on the management of neck dysfunction during functional movements.

Do changes within a manual therapy treatment session predict between-session changes for patients with cervical spine pain?

Physiotherapists often use within-session changes to provide a guide for refining treatment application. This study tested the validity of within-session changes as predictors of between-session changes for patients with neck pain receiving manual therapy treatment. A total of 70 pairs of treatments from 29 patients with sub-acute non-specific neck pain receiving manual therapy were assessed to determine the relationship between within-session and between-session changes in range of motion (ROM), pain intensity, and centralisation. Measurements were taken of ROM of the more limited direction on each axis of flexion, extension, lateral-flexion and rotation, and pain (intensity and location) before and after treatment. The same measurements were repeated before the following treatment. Regression analysis demonstrated that within-session change accounted for 26% to 48% of the variability in between-session change for ROM and six per cent for pain intensity. The proportion of the within-session change for ROM maintained between sessions ranged from 42% to 63% (95% CI 25% to 88%). The odds ratios for within-session improved/not improved categorisation to predict between-session category for ROM ranged from 2.5 (95% CI 0.6 to 4.3) to 21.3 (95% CI 10.1 to 96.1), for pain intensity 4.5 (95% CI 1.2 to 14.4) and for pain centralisation 9.2 (95% CI 2.2 to 38.7) indicating greater likelihood of between-session improvement after within-session improvement. The between-session results for most patients (71% to 83%) could be classified correctly by their within-session category. The results support the use of within-session changes in ROM, centralisation, and possibly pain intensity as predictors of between-session changes for musculoskeletal disorders of the cervical spine.

A Morphometric Investigation on Breed-Specific Features Affecting Sagittal Rotational and Lateral Bending Mobility in the Canine Cervical Spine (C3-C7)

Vertebral and inter-vertebral parameters obtained in large breeds (n = 74), small breeds (n = 35), and Dachshunds (n = 30) were compared to reveal potential differences in the range of motion of the cervical spine between these three groups of breeds. Body size normalized dimensions of vertebral and inter-vertebral parameters and correlations between these indicate large canine breeds to have a tendency towards higher range of motion in sagittal rotation and lateral bending compared with Dachshunds and small breeds. Higher mobility in large breeds is based on significantly (P < 0.05) lower vertebral endplate heights and widths, shorter vertebral bodies and longer inter-vertebral discs, wider but shorter cranial and caudal articular surfaces, larger differences in width between caudal and cranial joining facets (compared with Dachshunds from C3/4 to C6/7, compared with small breeds from C4/5 to C5/6), and larger differences in length between caudal and cranial joining facets. Large differences in width between caudal and cranial joining facets were associated with small distances between the most medial (C3/4 to C6/7) and lateral (C3/4 to C5/6) aspects of the articular surfaces as well as with small differences in length between caudal and cranial joining facets (C3/4 to C5/6). This suggests that from C3/4 to C5/6 a higher range of motion in lateral bending is coupled to a lower range of motion in sagittal rotation. The present findings contribute also to explain the higher incidence of degenerative lesions of the cervical spine in large dogs.

Zebris versus Myrin: a comparative study between a three-dimensional ultrasound movement analysis and an inclinometer/compass method: intradevice reliability, concurrent validity, intertester comparison, intratester reliability, and intraindividual variability

STUDY DESIGN

Experimental study.

OBJECTIVES

To compare two devices for measuring cervical range of motion, a three-dimensional ultrasound motion device (Zebris) and a gravity-reference goniometer (Myrin).

SUMMARY OF BACKGROUND DATA

Assessment of cervical range of motion is used to evaluate the effect of different treatments, determine impairment, and ascertain the relationship between neck disorders and cervical spine mobility.

METHODS

Sixty "neck-healthy" volunteers (25 men, 35 women; mean age 38 years, range 22-58 years) performed active maximal movements in flexion-extension, rotation, and lateral flexion. Maximal cervical range of motion was recorded simultaneously with the Zebris and Myrin devices. Intradevice reliability, concurrent validity, intertester comparison, intratester reliability, and intraindividual variability were computed.

RESULTS

Our study showed good agreement of full-cycle cervical range of motion measurement between devices, testers, and the test and retest (intraclass correlation [ICC] was >0.90 for intradevice reliability, >0.93 for concurrent validity, and >0.92 for intratester reliability). Method error, assessed with the within-subject coefficient of variation for 95% of the measurements, was 5.4% to 11.1% for intradevice reliability, 4.4% to 7.6% for concurrent validity, 3.6% to 7.6% for intratester reliability, and 5.3% to 9.9% for individual variability. Individual variability did not increase with an increased cervical range of motion.

CONCLUSION

Both devices are reliable and showed good agreement. We conclude that the two techniques can be used interchangeably. Our study supports the continued use of the Myrin-a gravity-reference goniometer in routine clinical orthopedic work. The more sophisticated three-dimensional method adds information and allows evaluation of combined motion in two and three dimensions and is suitable for research.

Physical function measurements in neck pain

The literature on physical and functional measurements for the cervical spine is more limited than for the lumbar spine. Most of the studies so far have dealt with the methods for range-of-motion measurements in the cervical spine. These studies indicate that newer computer-guided, three-dimensional measurements systems may provide more precise and reliable data than inclinometer-based techniques and visual estimation methods. The research available also shows a correlation between training and strength improvement in the cervical spine. In addition to physical measurements, several tests have been developed to measure pain level, psychologic factors, disability from neck pain, and generic health, which can assist the clinician in choosing the most appropriate treatment for patients with neck pain. Furthermore, functional measurement systems, such as FCEs, have been developed to describe the functional limitations that a patient may have as a result of a spinal injury. Except for the range-of-motion measurement methods, much more research is required to determine which measurement systems provide the optimal balance between reliability and validity and pragmatic considerations such as time and expense.

Three-dimensional analysis of active head and cervical spine range of motion: effect of age in healthy male subjects

OBJECTIVE

To assess the effect of age on active head-cervical range of motion in healthy men.

DESIGN

Three-dimensional cervical motion ranges and patterns were measured in 70 men.

BACKGROUND

The effect of age on cervical range of motion is still discussed.

METHOD

Twenty adolescent (mean age 16 year), 30 young adult (mean age 23 year), and 20 mid-aged (mean age 37 year) men performed maximal head and cervical spine flexion-extension, lateral bending, and axial rotation. Movements were detected using a digital optoelectronic instrument. Maximum head-cervical spine and thoracic motions were separated.

RESULTS

Flexion and extension were larger in the adolescents and young adults (130-132 degrees ) than in the mid-aged men (117 degrees ). Thoracic movement increased as a function of age. Lateral bending was symmetric, associated with head-cervical rotation and extension, and larger in adolescents (85 degrees ) than in young (77 degrees ) and mid-aged adults (79 degrees ). Axial rotation was symmetric, associated with flexion-extension and lateral bending, and similar in the three age groups (respectively, 160 degrees, 155 degrees, 153 degrees ).

CONCLUSIONS

Active head-cervical range of motion reduced between 15 and 45 years of age in men. Relevance The present data can be used as a reference for cervical range in motion in men between 15 and 45 years.

Pelvic mobility when bending forward in standing position: validity and reliability of 2 motion analysis devices

OBJECTIVE

To evaluate the validity and reliability of 2 measurement devices that assess pelvic mobility in persons bending forward while in a standing position.

DESIGN

Validity and reliability studies.

PATIENTS

The validity study included 10 patients (4 men, 6 women) aged 42 (range, 33--51yr). The reliability study included 50 subjects (25 men, 25 women) aged 30 (range, 18--49yr).

INTERVENTIONS

A 3-dimensional ultrasound motion analyzer (CMS 50) and a spine motion analyzer using potentiometers (Rachimètre).

METHODS

Two lateral radiographs of the patients' lumbosacral junction were taken, the first in neutral position, the second in full trunk flexion. Correlations between mobilities assessed by radiographs and both devices were evaluated by Spearman's rank correlation coefficient. Reliability was studied in healthy volunteers using the intraclass coefficient correlation (ICC) and the Bland and Altman plot.

RESULTS

Spearman's coefficient between radiographic measures and the Rachimètre and the CMS 50 evaluations were.89 and.81, respectively. For the Rachimètre, ICC was.65 and increased with a better standardization of the measurement procedures. For the CMS 50, ICC was.85, and the Bland and Altman plot revealed no systematic trend.

CONCLUSIONS

The Rachimètre and the CMS 50 have acceptable metric properties. Because few simple clinical measurements are available to evaluate pelvic mobility during trunk flexion in standing position, these 2 devices could be useful in the clinical evaluation of low back pain.

Reproducibility and instrument validity of a new ultrasonography-based system for measuring cervical spine kinematics

OBJECTIVE

To report instrument validity of CMS 70P, a new ultrasonography-based system for spatial kinematic analysis of the spine and its application in studying the reproducibility of cervical motion findings in healthy subjects.

BACKGROUND

Reproducibility of cervical motion has been investigated using various instruments and consisting in most cases of short test-retest time intervals of between minutes to days.

METHODS

Performance of the instrument was validated against a digital inclinometer, at ranges of motion compatible with actual cervical motion. To study reproducibility, 25 healthy individuals, 22 women and 3 men aged 26-48 were tested twice within an average time interval of 3.3 weeks. Performed in the seated position and at a self-determined pace, cervical motion was defined in terms of head motion relative to a sternal (reference) system, in all six primary motions: flexion, extension, right rotation, left rotation, right lateral flexion and left lateral flexion.

RESULTS

The system exhibited excellent agreement with the digital inclinometer, establishing its instrument validity for testing cervical motion. No significant differences were indicated between the test and retest for both the net maximal displacements and average velocities. The correlation coefficients for the single plane motions (e.g. flexion+extension) were higher than those derived for the primary motions, and ranged between 0.78 (sagittal plane) and 0.88 (frontal plane). The magnitude of the standard error of the measurement reflected the same trend with the lowest value recorded for the frontal plane. The self-selected velocity at which these motions were performed was similar in the frontal and saggital planes but was significantly higher for the transverse plane (rotations).

CONCLUSIONS

This study indicates that spanned over time intervals that are measured in weeks, cervical motion findings derived from the CMS 70P are well reproducible. Findings also imply the need for a more stringent control of subject positioning and stabilization.

RELEVANCE

Reduction of range of motion and average is typically observed in various pathologies of the cervical spine and is regarded, together with pain, as a major impairment. Therefore, valid assessment of cervical motion which is essential for follow-up and treatment outcome strongly depends on reproducibility of the findings. This study indicates that acceptable reproducibility is maintained over periods of time which are clinically meaningful using the system described herewith.