Cervical Muscle Endurance Research Articles

Correlation of psychosocial factors with pain, posture, function, and disability in chronic mechanical neck pain patients: a cross-sectional study

BackgroundChronic neck pain is a common musculoskeletal condition that has an impact on the function and quality of life of an individual. Psychosocial factors along with the physical factors may have an impact on the perception of pain. Hence, the study aimed to find the correlation of psychosocial factors with pain, posture, function, and disability in chronic mechanical neck pain patients.MethodA cross-sectional study using a convenient sampling method was conducted in 55 chronic mechanical neck pain patients. The pain was assessed using numerical pain rating scale (NPRS), pain pressure threshold (PPT) using a pressure algometer, kinesiophobia using Tampa Scale for Kinesiophobia (TSK), pain catastrophizing using Pain Catastrophizing Scale, Posture analysis was done by various postural angle and flexicurve, cervical muscle endurance was tested using the craniocervical flexion test, cervical proprioception was measured using head repositioning accuracy test and Neck disability index was used to score disability.ResultA significant positive correlation was found between TSK and NDI (r = 0.34, p = 0.01). There is a negative correlation of PTT (right sternocleidomastoid) with Kinesiophobia (r = − 0.35, p = 0.008). There is a moderate positive correlation between posture (shoulder angle on the left side) and TSK (r = 0.3, p = 0.02).ConclusionThe study concludes that psychosocial factors not only have a significant role but are correlated to pain, posture, function, and disability in patients with chronic mechanical neck pain.

The association between mobile phone usage duration, neck muscle endurance, and neck pain among university students

The mobile phone is essential in daily life, especially during the pandemic. Prolonged use can cause postural issues, leading to common neck pain. This study aims to determine the correlation between mobile phone use duration, addiction, neck muscle endurance, and neck pain in university students. The study included 62 participants (30 female, 32 male) aged 18–35 years. Inclusion criteria required participants to have experienced neck pain at least twice in the past year and to have no other concomitant issues, as well as to volunteer for the study. Demographic information and daily mobile phone usage time were collected. Neck pain was assessed with the Visual Analogue Scale, smartphone addiction with the Smartphone Addiction Scale, and cervical muscle endurance was evaluated. Correlation analysis reveals a moderate relationship between neck pain severity (NPS) and cervical extensor muscle endurance (CEME), a strong relationship between NPS and cervical flexor muscle endurance (CFME), as well as a strong relationship among daily phone usage time (DPUT), CFME, and NPS, with a moderate relationship between DPUT and CEME. Participants were divided into two groups based on their DPUT, revealing that those who used their phone for four hours or more showed significantly higher levels of pain (p < 0.05) and reduced endurance in cervical flexor muscles. Our study found a strong correlation between neck pain, muscle endurance, and daily phone usage. Participants using their phones for more than four hours daily reported increased neck pain and decreased muscle endurance. We suggest integrating phone usage duration into neck pain assessments, promoting ergonomic practices, and offering detailed usage guidelines for users.

A Profile of Isometric Cervical Strength in Elite Professional Male Rugby Players.

OBJECTIVES: To (1) provide position-specific normative data for isometric cervical muscle strength and endurance in professional, male rugby players and (2) assess the relationship between age, height, weight, and playing position with cervical muscle strength and endurance. DESIGN: Cross-sectional study. METHODS: Professional rugby players completed peak isometric cervical strength testing followed by a test of cervical muscle endurance. Descriptive statistics for continuous variables with strength normalized to body weight were performed. Multiple linear regression was used to estimate associations between strength measurements. RESULTS: In total, 136 players participated including front-row forwards (27%), other forwards (28%), and backs (45%). Front-row forwards had significantly greater peak isometric cervical muscle strength than other position groups, with backs having the lowest strength. Extension produced the highest force for all 3 position groups (429 N ± 104 N), whereas flexion produced the least (275 N ± 65 N). Age was associated with increased isometric cervical muscle strength. There was a statistically significant relationship between peak flexion strength and flexion endurance (P = .003). The average time for the endurance tests were 55.7 (±17.1) seconds and 52.9 (±20.1) seconds for extension and flexion, respectively. Other forwards had lower cervical extension muscle endurance than backs and front-row forwards. CONCLUSIONS: Normative values for peak and endurance isometric strength in professional rugby players illustrate significant differences between playing position. Consider age, body weight, and intraindividual variability when interpreting cervical strength and endurance results. J Orthop Sports Phys Ther 2024;54(3):1-8. Epub 29 January 2024. doi:10.2519/jospt.2024.11830.

Relationship Between Temporomandibular Joint Disorder Level and Clinical Parameters in Patients with Fibromyalgia Syndrome

Relationship Between Temporomandibular Joint Disorder Level and Clinical Parameters in Patients with Fibromyalgia Syndrome

Randomised controlled trial assessing the effects of 6-week telerehabilitation exercise programme on chronic non-specific neck pain: a study protocol

Chronic non-specific neck pain is one of the most common musculoskeletal conditions affecting the work and lifestyle of those suffering from it. Physiotherapy interventions, such as strength training and stretching,...

KRONİK BOYUN AĞRISINDA SERVİKAL STABİLİZASYON EGZERSİZLERİ İLE KOMBİNE EDİLEN MULLİGAN MOBİLİZASYON TEKNİĞİNİN ETKİLERİNİN TEK BAŞINA SERVİKAL STABİLİZASYON EGZERSİZLERİNİN ETKİLERİ İLE KARŞILAŞTIRILMASI: RANDOMİZE KONTROLLÜ ÇALIŞMA

Objective: The aim of the study was to compare the effects of Mulligan mobilization techniques applied in addition to cervical stabilization exercises on pain intensity, range of motion (ROM), cervical muscle endurance, pressure pain threshold (PPT), and quality of life compared to cervical stabilization exercises alone in individuals with chronic neck pain (CNP).&#x0D; Method: Forty individuals with CNP were included in the study and randomly divided into two groups: the cervical stabilization group (SG, n=20) and the cervical stabilization-Mulligan mobilization group (SMG, n=20). The SG group only received cervical stabilization exercises for four weeks, while the SMG received Mulligan mobilization techniques for four weeks in addition to cervical stabilization exercises. Before and after the treatment programs, the subjects were evaluated in terms of pain intensity (visual analogue scale), ROM (goniometric measurement), cervical muscle endurance (endurance tests), PPT (algometric measurement), and quality of life (Short Form-36, SF-36).&#x0D; Results: Significant improvements were found in all parameters in both groups after the treatment programs (p

Cervical muscle parameters and allodynia in migraine and cervical pain-A controlled study.

Neck pain is common among individuals with migraine, but there is a lack of information of how this comorbidity can be associated with cervical muscle function. This controlled cross-sectional study aimed to compare cervical muscle function, activity, and sensitization in women with migraine, neck pain, both, and neither. This study included women, between 18 and 55 years old, with either episodic migraine with or without aura, without any concomitant headache diagnosis; chronic neck pain, with at least moderate intensity and mild disability; or neither headache nor neck pain. Pain pressure threshold, allodynia, muscle strength, and endurance and cervical muscles activity were evaluated. One hundred subjects, with mean age of 30.4 years old, were stratified by diagnosis (n = 25 per group) and by self-reported pain during tests. Lower endurance during flexion was observed for migraine and neck pain (34s) relative to neck pain alone (45s), migraine (40s), and controls (58s) (p = 0.04). For extensor endurance, means were 142s, 166s, 215s, and 270s, respectively (p < 0.001). Endurance times were impacted by the presence of test-induced pain decreasing about 40%-53% of the performance. Diagnostic groups did not differ significantly in strength (p > 0.05), but all pain groups presented significantly higher proportion of test-induced pain, lower muscle activity during the maximal isometric voluntary contractions, and lower pressure pain thresholds. Patients with migraine, chronic neck pain, and the association of both present altered cervical muscle function and activity. Also, test-induced pain impacts significantly on neck muscles endurance. The diagnosis of migraine and chronic neck pain is associated with altered function and activity of the cervical muscles. However, the test-induced pain had an important contribution to worse cervical muscle endurance. This suggests that the therapeutic approach should focus on de-sensitization of the trigeminal-cervical complex when dealing with the comorbidity of migraine and cervical pain.

Cervical proprioception in Parkinson's disease and its correlation with manual dexterity function.

Cervical proprioception has a crucial role in posture and movement control. The study aimed to determine the relationship of cervical proprioception, cervical muscle strength and endurance with manual dexterity and hand strength in individuals with idiopathic Parkinson's disease (PD). Twenty individuals with PD (mean age:63.9 years) and 20 healthy individuals as a control group (mean age: 61.9 years) were recruited. Cervical joint position error (JPE), static endurance of neck muscles, activation of deep cervical flexor muscles (Craniocervical Flexion Test-CCFT), manual dexterity using Purdue Pegboard Test (PPT), cognitive and motor task on PPT, finger tapping test (FTT) and pinch-grip strength were assessed. Cervical JPE was significantly higher in individuals with PD than controls (p<0.05). The strength and endurance of the cervical muscles were significantly decreased in individuals with PD (p<0.05). There was a significant negative correlation of cervical JPE measurements with PPT, cognitive and motor tasks on PPT in the PD group (p<0.05). There was a significant negative correlation of the endurance of cervical flexor muscles with PPT and cognitive task on PPT (p<0.05). In addition, a significant positive correlation was found between cervical flexor endurance and hand strength in the PD group (p<0.05). Cervical proprioception and the strength and endurance of cervical muscles decrease in individuals with PD compared to healthy individuals. Impairment of cervical proprioception appears to be associated with poorer upper extremity performance. Detailed evaluation of the cervical region in PD may be useful in determining the factors affecting upper extremity function.

Network analyses reveal the interaction between physical features, fear of movement and neck pain and disability in people with acute and chronic whiplash-associated disorders.

A network analysis can be used to quantitatively assess and graphically describe multiple interactions. This study applied network analyses to determine the interaction between physical and pain-related factors and fear of movement in people with whiplash-associated disorders (WAD) during periods of acute and chronic pain. Physical measurements, including pressure pain-thresholds (PPT) over neural structures, cervical range of motion, neck flexor and extensor endurance and the cranio-cervical flexion test (CCFT), in addition to subjective reports including the Tampa Scale of Kinesiophobia (TSK-11), Neck Disability Index (NDI) and neck pain and headache intensity, were assessed at baseline in 47 participants with acute WAD. TSK-11, NDI and pain intensity were assessed for the same participants 6 months later (n = 45). Two network analyses were conducted to estimate the associations between features at baseline and at 6 months and their centrality indices. Both network analyses revealed that the greatest weight indices were found for NDI and CCFT at baseline and for neck pain and headache intensity and NDI and TSK-11 at both time points. Associations were also found betweeen cervical muscle endurance and neck pain intensity in the acute phase. Cervical muscle endurance assesssed during the acute phase was also associated with NDI after 6 months - whereas PPT measured at baseline was associsated with headache intensity after 6 months. The strongest associations were found for headache and neck pain intensity and neck disability and fear of movement, both during acute pain and when mesured 6 months later. The extent of neck endurance and measures of PPT at baseline may be associated with neck disability and headache, respectively, 6 months after a whiplash injury. Through two network analyses, we evaluated the interaction between pain-related factors, fear of movement, neck disability and physical factors in people who had experienced a whiplash injury. We demonstrated that physical factors may be involved in the maintenance and development of chronic pain after a whiplash injury. Nevertheless, the strongest associations were found for headache and neck pain intensity and neck disability and fear of movement, both during acute and chronic phases.

Relationship between cutaneous allodynia, cervical muscle strength and endurance in women with migraine

IntroductionMigraine is a primary headache disorder with generalized neuronal hyperexcitability. Migraine individuals have a high prevalence of cutaneous allodynia, neck pain, and reduced cervical isometric strength. Lower isometric strength is also known to correlate with greater severity of cutaneous allodynia. However, the correlation between cervical muscle endurance and cutaneous allodynia is not yet known. ObjectiveTo evaluate the correlation between cervical muscle strength and endurance with cutaneous allodynia in migraine women. MethodsSeventy migraine women were recruited by local community advertisements. Were included women aged between 18 and 55 years and migraine diagnosis. An experienced neurologist diagnosed potential participants with migraine according to the third edition of the International Classification of Headache Disorders (ICHD-3). Participants were excluded if they underwent an anesthetic nerve block; presented with any other concomitant headache, such as cervicogenic or tension-type headache, degenerative cervical conditions, or history of trauma at the neck and face, or pregnancy.The Multi Cervical Rehabilitation Unit (MCU) was used to assess cervical isometric muscle strength and cervical muscle endurance. The assessment of cervical isometric strength was obtained through three repetitions of the movement in flexion, extension, and lateral flexion. The endurance of cervical flexors and extensors muscles was obtained using 50% of the maximum voluntary isometric contraction. The MCU is a device with excellent reliability (ICC 0.92–0.99) for assessing cervical muscle strength and endurance.Cutaneous allodynia was evaluated using the Allodynia Symptom Checklist (ASC-12), a reliable, quick, and simple tool with excellent psychometric properties, compound of 12 questions that allows to classify the severity of cutaneous allodynia. The questionnaire was validated for the Portuguese language and it is able to diagnose and classify allodynia in the Brazilian population, in order to facilitate the identification of symptoms in a reliable and fast manner (ASC-12). (To see the complet abstract, please, check out the PDF.)

How does pain influence cervical endurance test performance in migraine patients?

Introduction Migraine sufferers frequently complain of cervical pain during and in-between migraine attacks and studies suggest that chronic neck pain is a risk factor for high-frequency migraine, including chronic migraine. Increased headache frequency and chronic neck pain are, in turn, independently associated with cephalic cutaneous allodynia, a known risk factor for increased headache frequency. Objective To verify the influence that pain in migraine patients has on muscle performace during the cervical endurance test and whether the change in performance is due to pain during the test, neck muscle dysfunction or both. Methods Were evaluate 100 women stratified by diagnosis (migraine, cervical pain, both and none) and self-reported pain during the cervical muscle endurance test in flexion and extension (with or without headache and / or cervical pain during the endurance test). Pain during the test by numerical rate scale (NPRS, 0-10) and pain pressure threshold were collected for all groups. Migraine patients answered 12-item Allodynia Symptom. We used one-way analysis of variance with the Tukey’s HSD post hoc test analysis to contrast pressure pain threshold and endurance across groups. Differences in flexion and extension times were compared using the Welch T-test and the McNemar Test was used to compare differences in headache and neck pain incidence per study group during flexion and extension endurance tests. Results There are significantly differences in mean endurance during flexion between migraine and neck pain [34.4s (25)] relative to neck pain alone [45.2 (18)], migraine [40.2s (29)] and controls [57.5.4s (40)] (p = 0.04). On average, those who experienced headache during the flexion test sustained for significantly less time than those without headache during the test (27.80 versus 46.18 seconds, p&lt;0.01); (To see the complete abstract, please, check out the PDF).

Correlation between Deep Cervical Muscle Endurance, Cervical Proprioception, and Chronic Neck Pain: A Cross-Sectional Analysis Study

The main aim of the study was to investigate the relationship among deep cervical muscle endurance, cervical proprioception, and chronic neck pain (CNP). Subjects with CNP (n=47) aged 20 to 45 years were recruited to the study. Cervical joint position sense error (JPSE), deep cervical flexor and extensor endurance, pain intensity and neck pain associated disability were investigated by using common clinical tests. The correlations between measured variables were assessed by Spearman correlation coefficients. Only extension cervical JPSE component showed significant fair correlation with pain (σ = 0.30, p = 0.040) and disability (σ = 0.39, p = 0.006). Both the cervical flexor and extensor muscle endurance were found to have no relationship with both pain and disability. There was no association between deep cervical muscle endurance and the cervical JPSE. But a significant fair correlation was noted between the cervical flexor and extensor muscle endurance capacity (σ = 0.38, p = 0.008). Deep cervical muscle endurance and cervical proprioception were weakly associated with CNP. Chronic neck pain might not influence neck muscle endurance and cervical proprioception. Muscle endurance capacity and proprioceptive functioning also seem to be irrelevant to each other in people with CNP.

Effectiveness of Cervical Muscle Endurance Training in Patients with Mechanical Neck Pain

Effectiveness of Cervical Muscle Endurance Training in Patients with Mechanical Neck Pain

Comparative study of observed actions, motor imagery and control therapeutic exercise on the conditioned pain modulation in the cervical spine: a randomized controlled trial

Aim: The aim of this study was to compare the effects of cervical exercise, motor imagery (MI) and action observation (AO) of cervical exercise actions on conditioned pain modulation and pressure pain thresholds. The second objective was to assess the effects of these interventions on cervical motor activity (ranges of motion and muscle endurance), attention, and the ability to generate motor images.Study design: Single-blinded randomized controlled trial.Materials and methods: Fifty-four healthy subjects were randomly assigned to each group. Response conditioned pain modulation, pressure pain threshold, were the main variables. The secondary outcome measures included, cervical range of motion, Neck flexor endurance test, mental movement representation associated and psychosocial variables.Results: All groups showed significant differences in time factor for all evaluated variables (p < .01) except pressure pain threshold over the tibial region. The post hoc analysis revealed significant within-group differences in the AE and AO groups in conditioned pain modulation (p < .05), with medium effect size in time [AE (d –0.61); AO (d –0.74)].Conclusion: The results showed that within-group changes in conditioned pain modulation, cervical muscle endurance, and attention where founded only in the AE and AO groups. Variations in pain thresholds at pressure in the trapezium area were also obtained in the three groups. Changes in the ranges of flexion-extension and rotation movement were presented exclusively in the exercise group, and in the capacity to generate motor images only in the AO group. However, there was no difference in the pressure pain threshold over the tibial region.

Cervical Sagittal Balance as a Predictor for the Outcome of Multimodal Treatment Program for Non Specific Neck Pain

AbstractBackground: Sagittal balance represents the position of the occiput to the thoracic inlet. Sagittal balance keep normal lordotic curve in cervical region so any disturbance in cervical balance lead to pain and disability. Also it an important concept in spinal reconstruction and cervical sagittal imbalance has been linked to poor health-related quality of life scores due to disabling symptoms of neck pain and neurological deficit.Aim of Study: The purpose of this study was to investigate the influence of cervical balance as predictor for the outcome measures of multimodal treatment program in patient with non specific neck pain.Patients and Methods: Forty patients with non specific neck pain participated in this study. Patients were subdivided into two groups, twenty in each group. The first group was the group A with cervical sagittal imbalance, and the second group was the group B with cervical sagittal balance. Both groups received multimodal treatment (cervicothoracic stabi-lization training designed to restore cervical muscle endurance and coordination, relaxation training to reduce unnecessary muscle tension, behavioral support to reduce anxiety and fear of pain, eye fixation exercises to prevent dizziness and seated wobble-board training to improve postural control). We measured pain by Visual Analogue Scale (VAS), neck function by Neck Disability Index (NDI) and cervical Range of Motion (ROM) by cervical goniometer.Results: Within-group analysis there was a significant difference of, NDI and ROM (flexion, extension, RT rotation and LT rotation) pre-treatment at groups A, B (p=0.0001). There was no significant difference of VAS, LT bending and RT bending pre-treatment (p-value >0.05). Between group analyses there was significant difference of NDI and ROM (flexion, extension, RT bending, LT bending, RT rotation and LT rotation) in two groups post-treatment as p-value <0.05 except VAS.SVA (Sagittal Vertical Axis) contribute to interpretation of changes in ROM NDI except VAS.Conclusion: Cervical sagittal balance is effective in predicting multimodal treatment outcome measures (ROM and neck function) in Nonspecific Neck Pain (NSNP). Patients with cervical sagittal balance have better outcome measures (improving ROM and improving neck function) than patients with cervical sagittal imbalance in case of non specific neck pain.

Exploring the role of cervical spine endurance as a predictor of concussion risk and recovery following sports related concussion

BackgroundConcussions have become a significant public health concern with rising incidence rates. Concussions have been shown to occur concurrently with neck injuries, such as whiplash-associated-disorder, therefore, understanding the role of the neck in concussions is important. ObjectivesTo determine if there is a relationship between cervical muscle endurance and either concussion incidence, or concussion recovery in university athletes. Specifically, the primary aim was to investigate a relationship between pre-season deep neck flexor endurance test (DNFET) time in those who sustained an in-season injury versus those who did not. The secondary aim is to determine correlation in DNFET times and concussion recovery. DesignLongitudinal observational study. MethodsPre-season DNFET was performed on university athletes. In the event of a concussion, cervical endurance and neuromuscular adaptation was re-assessed with the DNFET. Rehabilitative exercises were prescribed, as required, and DNFET was measured at subsequent treatments. ResultsThere was no significant difference between pre-season DNFET times and concussion incidence (p = 0.55). However, there was a moderate correlation between DNFET times and concussion recovery (R = 0.47, p = 0.001) whereby DNFET times improved predictively throughout rehabilitation. ConclusionsWhile no statistically significant relationship was found between DNFET and concussion incidence, a significant clinical relationship was present with recovery. The validity of the DNFET test as a means for assessing risk or measuring recovery requires additional research.

Effects of cervical stabilization/strengthening exercises in violinists with chronic nonspecific neck pain

Violinists frequently assume an asymmetrical neck posture and activate their superficial neck flexor muscles to stabilize the violin for prolonged playing. It is unclear whether this augmented activation of superficial neck flexors may influence the effects of stabilization exercises for violinists with neck pain. The aim of this study was to investigate the effect of cervical stabilization/strengthening exercises on pain intensity, function, sensorimotor function, and upper body posture in violin players with chronic nonspecific neck pain. The one-group pretest-posttest design with a double pretest was used. Violin players with chronic nonspecific neck pain were recruited from students of a university symphony orchestra. Pain intensity (numeric rating scale), function (Neck Disability Index), sensorimotor function (Craniocervical Flexion Test, cervical muscle endurance tests, cervical range of motion tests, and cervical reposition error tests), and upper body posture were assessed at three time points (week 0, 4, and 10). After the completion of two pretests, participants followed instructional videos and performed cervical stabilization/strengthening exercises, 20 minutes a day, 3 days a week for 6 weeks. Twenty-four participants were initially enrolled, and 20 completed all testing sessions. Participants reported moderate neck pain and no disability at week 0. The outcome measures of pain intensity, function, and sensorimotor function showed statistically significant improvement during the intervention period (week 4 vs. week 10). Meanwhile, these outcome measures remained relatively unchanged during the baseline period (week 0 vs. week 4). For the outcome measure of upper body posture, only the craniovertebral angle relative to the horizontal plane significantly increased during the intervention period. Six-week video based cervical stabilization/strengthening exercises resulted in clinically meaningful and beneficial effects. A randomized controlled study with a larger sample is suggested to further investigate the effects of cervical stabilization/strengthening exercises in violin players with more severe neck pain.

Functional limitations and associated psychological factors in military personnel with chronic nonspecific neck pain with higher levels of kinesiophobia.

Neck pain is one of the largest health problems in the military sector. To assess differences in the strength and endurance of the cervical muscles between military personnel with chronic nonspecific neck pain (CNSNP) with higher level of kinesiophobia (CNSNP-K) and individuals with lower levels of kinesiophobia (CNSNP-NK). We used kinesiophobia as a classification method: (1) CNSNP-K and (2) CNSNP-NK. The variables measured were endurance and strength of cervical muscles; range of motion (ROM), disability, pain intensity and psychological factors. Eighty-three military personnel (26 CNSNP-K; 20 CNSNP-NK and 37 asymptomatic). Statistically significant differences in endurance and ROM were only found between the CNSNP-K group and the control group. In strength and disability differences were revealed between both symptomatic groups and the control group [CNSNP-K vs. control (flex-ext p < 0.001); CNSNP-NK vs. control (flex p = 0.003) and (ext p < 0.001)]. For psychological variables, the CNSNP-K group showed differences compared with the CNSNP-NK (pain catastrophizing, p = 0.007; anxiety and depression, p < 0.001) and with the asymptomatic group (pain catastrophizing, p = 0.008; anxiety and depression, p < 0.001). Military personnel with CNSNP-K have functional limitations and associated psychosocial factors compared with asymptomatic subjects, and showed greater associated psychological factors than CNSNP-NK group. Military personnel with CNSNP-NK only showed decreased strength with respect to those who were asymptomatic.

Is the clinical cervical extensor endurance test capable of differentiating the local and global muscles?

Background ContextDifferential alterations have been reported in the local and global cervical muscles in the presence of chronic neck pain (CNP), including the endurance alterations of these muscles. Identifying the involved muscles is crucial to the assessment and rehabilitation of patients with CNP. PurposeTo assess the relationship between clinical endurance test results, pain and disability indices, and ultrasonographic (US) measurements of the neck extensor muscles; to compare the deep and superficial cervical extensor muscle endurance and size of CNP patients with those of asymptomatic subjects and to compare the relationship between local and global extensor endurance with US measures, pain intensity, and disability. Study Design/SettingCross-sectional correlational analysis with a case-control design. Patient SampleThirty patients with CNP and 30 asymptomatic subjects participated in this study. Outcome MeasuresEndurance, thickness, cross-sectional area, and shape ratio of the cervical extensor muscles (splenius capitis [SpCap], semispinalis capitis [SSCap], semispinalis cervicis [SSCer], and multifidus [MF]); pain intensity measured by the visual analog scale (VAS); neck disability index (NDI); correlation between US measures, pain intensity and NDI and extensor endurance; and correlation of US measures with pain intensity and NDI. MethodsThe deep and superficial cervical extensor muscle endurance and dimensions were measured via a clinical test and by US, respectively. Participants were asked to hold the neutral chin-tuck position while lying prone. The test would be terminated if the head moved into either flexion or extension, which would yield “global” or “local” extensor muscle endurance, respectively. ResultsThe CNP patients showed lower global extensor endurance levels than the control participants (p<.05). The US measures of the deep extensor muscles were also smaller in the CNP group (p<.05). There were no significant correlations between extensor endurance test results and US measures in either group except for the SSCap muscle size with local and total endurance (p=.04 for both) of CNP and control participants, respectively. NDI was correlated with SpCap and SSCer muscle thicknesses in a positive and negative manner, respectively (p=.03 for both). There was also a significant correlation between MF size and VAS (p<.05). ConclusionsThe findings showed higher levels of global muscle fatigability and smaller size of deep neck extensor muscles in CNP patients. Disability and extensor endurance were found to be associated with extensor muscle size. The results challenge the validity of the clinical extensor muscle endurance test in the differentiation of the deep and superficial extensor muscle endurance and the use of US in the assessment of cervical muscle endurance. Further investigations are needed to judge the superficial and deep muscle endurance in CNP patients.

Local Muscle Fatigue and 3D Kinematics of the Cervical Spine in Healthy Subjects

ABSTRACTThe authors aimed to further explore the effects of local muscle fatigue on cervical 3D kinematics and the interrelationship between these kinematic characteristics and local muscle endurance capacity in the unimpaired cervical spine. Twenty healthy subjects (38 ± 10 years; 5 women) performed 2 × 10 maximal cervical flexion–extension movements. Isometric muscle endurance tests (prone/supine lying) were applied between sets to induce local muscle fatigue quantified by Borg scale rates of perceived exertion (RPE) and slope in mean power frequency (MPF; surface electromyography; m. sternocleidomastoideus, m. splenius capitis). Cervical motion characteristics (maximal range of motion [ROM], coefficient of variation of the 10 repetitive movements, mean angular velocity, conjunct movements in transversal and frontal plane) were calculated from raw 3D ultrasonic movement data. Average isometric strength testing duration for flexion and extension correlated to the cervical ROM (r = .49/r = .48; p < .05). However, Student's t test demonstrated no significant alterations in any kinematic parameter following local muscle fatigue (p > .05). Although subjects' cervical muscle endurance capacity and motor output seems to be conjugated, no impact of local cervical muscle fatigue on motor function was shown. These findings underline the importance of complementary measures to address muscular performance and kinematic characteristics in outcome assessment and functional rehabilitation of the cervical spine.