Neck Flexor Endurance Research Articles

CIRNE III Abstracts: Congresso Internacional de Reabilitação Neuromusculoesquelética e Esportiva, May 18–21, 2011, Vitória, Brazil

CIRNE III Abstracts: Congresso Internacional de Reabilitação Neuromusculoesquelética e Esportiva, May 18–21, 2011, Vitória, Brazil

Predictors of neck pain among South African youth

Globally, adolescent neck pain has not been identified as a widespread problem. The prevalence of musculoskeletal pain is rising among adolescents, possibly as a result of repetitive movements and static postures associated with increased use of computers. The aim of this study was to determine the prevalence of, and factors predicting neck pain in learners attending high schools in the Gauteng Province, South Africa. The Computer Usage Questionnaire which investigated the prevalence of neck pain, as well as the use of computers, involvement in sports activities and psychological factors were used to collect data in conjunction with the neck flexor muscle endurance test. Associations between variables were conducted using the Chi-square test and crude odds ratio in the univariate core, while logistic regression was employed in the analysis to identify predisposing factors. The study sample included 181 learners made up of 97 males (53.6%) and 84 females (46.4%). The mean age of the participants was 16± 1.10 years. The neck pain prevalence was 53.6%. School computer use (p= 0.4) and sport participation (p=0.09) were not significant predisposing factors. However, computer use outside of school (p=0.03) and neck flexor muscle endurance (p= 0.00) were significant predisposing factors to neck pain. The results of the study highlight the need to incorporate education about postural care specifically among adolescents who are engaging more frequently with information technology leading to increased computer usage.Keywords: Neck pain, prevalence, adolescents, physical activity, computer use, neck flexor, muscle endurance.

The Deep Neck Flexor Endurance Test: Normative Data Scores in Healthy Adults

To investigate (1) the average hold time for the deep neck flexors (DNF) endurance test in subjects without neck pain or pathology, and (2) whether different groups of subjects categorized by age, gender, and lifestyle display different hold times. Normative research. A convenience sample of 126 adults participated. Intertester reliability of 4 therapists was evaluated by using intraclass correlation coefficients. The DNF endurance test hold time was conducted on each subject twice. The 2 hold-time scores were averaged and recorded. Inter-rater reliability coefficient of reproducibility for DNF muscle endurance measured by 4 physical therapists was ICC (2,k) 0.66 (confidence interval, 0.34-0.86). The mean (SD) DNF endurance hold times for men was 38.9 ± 20.1 seconds, whereas women was 29.4 ± 13.7 seconds. Results of the 2 x 2 analysis of variance indicated that gender significantly influenced DNF endurance (F = 8.643; P = .004), whereas, the activity level did not (F = 3.143; P = .079). Correlations were not significant between age and DNF endurance (r = 0.11; P = .2) and between activity level and DNF endurance (r = -0.156; P = .08). Asymptomatic men displayed greater DNF endurance than women. The variability between subjects' DNF endurance capabilities was high. Age between 20 and 80 years and activity level did not affect DNF endurance. This is the first normative data set available for the DNF endurance test, which lays the foundation for further research in subjects with a history of cervicalgia and assists clinicians to objectify a milestone for DNF endurance deficits in patients.

Endurance and fatigue characteristics of the neck flexor and extensor muscles during isometric tests in patients with postural neck pain

Sustained postural loading of the cervical spine during work or recreational tasks may contribute to the development of neck pain. The aim of this study was to compare neck muscle endurance and fatigue characteristics during sub-maximal isometric endurance tests in patients with postural neck pain, with asymptomatic subjects. Thirteen female patients with postural neck pain and 12 asymptomatic female control subjects completed timed sub-maximal muscle endurance tests for the neck flexor and extensor muscles. Muscle fatigue, defined as the time-dependent decrease in median frequency electromyography (EMG), was examined using surface EMG analysis during the tests. The median extensor test holding time was lower but not significantly different in the neck pain group (165 s) that the control group (228 s) ( p = 0.17). There was no difference between groups in the flexor test holding time (neck pain = 36 s, controls = 38 s) ( p = 0.96). The neck pain group was characterised by greater variability in neck flexor ( p = 0.03) and extensor ( p = 0.006) muscle endurance. For both tests, the rate of decrease in median frequency EMG was highly variable within and between groups with no significant difference between groups for the flexor or extensor test ( p = 0.05–0.82). Patients with postural neck pain did not have significant impairment of neck muscle endurance or accelerated fatigue compared to control subjects. However, the greater variability in these indices of muscle function may reflect patient-specific changes in muscle function associated with neck pain disorder.

Reduced endurance of the cervical flexor muscles in patients with concurrent temporomandibular disorders and neck disability

Subjects with temporomandibular disorders (TMDs) have been found to have clinical signs and symptoms of cervical dysfunction. Although many studies have investigated the relationship between the cervical spine and TMD, no study has evaluated the endurance capacity of the cervical muscles in patients with TMD. Thus the objective of this study was to determine whether patients with TMD had a reduced endurance of the cervical flexor muscles at any level of muscular contraction when compared with healthy subjects. One hundred and forty-nine participants provided data for this study (49 subjects were healthy, 54 had myogenous TMD, and 46 had mixed TMD). There was a significant difference in holding time at 25% MVC between subjects with mixed TMD when compared to subjects with myogenous TMD and healthy subjects. This implies that subjects with mixed TMD had less endurance capacity at a lower level of contraction (25% MVC) than healthy subjects and subjects with myogenous TMD. No significant associations between neck disability, jaw disability, clinical variables and neck flexor endurance test were found.

The Interplay of Static and Dynamic Postural Factors in Neck Pain

Abstract The objectives of this study were to compare published methods of measuring cervical posture and to determine whether these measures were associated with clinical endpoints such as pain and disability levels, and postural muscle performance in the upper quarter. A cross-sectional study design was used, and the study was conducted at two call centres in Newcastle, New South Wales. The participants comprised 34 call centre operators with no history of neck trauma, using visual display terminals for a minimum of 4 hours per day. The main outcome measurements were correlations between angular measurements of posture, and correlations of postural measures with Northwick Park neck pain questionnaire, deep cervical flexor muscle performance, global neck flexor muscle and shoulder girdle endurance, and demographic factors. Moderate correlations of craniovertebral angle with cervical inclination ( r = 0.61) and lower cervical angle ( r = 0.47) existed. Moderate correlation existed between upper thoracic inclination and lower cervical angle ( r = 0.55). Neck pain questionnaire scores were significantly associated with craniovertebral angle ( p = 0.01). No postural muscle performance measures were associated with postural measures. Stratification by sex revealed trends between posture and demographic and muscle performance measures, with systematic reversal of correlations between sexes. Three postural measures indicated forward head posture with some agreement. Contradictory findings between sexes are systematic and indicate that sexes should be analysed separately.

경부 통증 유무에 따른 심부 경부 굴곡근의 근력과 지구력 비교

The purpose of this study was to investigate the strength and endurance of the deep neck flexor muscles in individuals with work-related neck pain. Subjects consisted of two groups: twenty industrial workers with neck pain and twenty age-matched healthy subjects. To evaluate the strength and endurance of deep cervical flexors, maximum voluntary contractile strength (MVCS) and a sustained time at sub-maximal voluntary contractile strength (SMVCS) (80% and 50% of MVCS) were measured using a pressure biofeedback unit and a stop watch in supine. The MVCS of deep neck flexor muscles was 29.67±4.56 in neck pain group and 54.27±6.78㎜Hg in normal group. The sustained time at 80% SMVCS was 12.42±2.64 seconds and 55.12±12.76 seconds in the groups with and without neck pain. The sustained time at 50% SMVCS was 25.40±5.88 seconds and 109.70±31.50 seconds in the groups with and without neck pain. The difference of the lower jaw position was 16.75±3.57㎜ and 23.03±2.51㎜. The MVCS, endurance at the two sub-maximal levels and the difference of the lower jaw position were significantly greater in the group without neck pain than with neck pain (p＜0.05). The findings indicate that the maximal strength and endurance of the deep neck flexors were decreased in the workers with neck pain compared to those without neck pain. Therefore, it is necessary to include strengthening and endurance exercises of the deep neck flexor muscles in therapeutic program of work-related musculoskeletal disorders involving neck pain.

Neck flexor muscle fatigue in adolescents with headache – An electromyographic study

Background Muscular disorders of the neck region may be of importance for the etiology of tension-type headache. However, in adolescents, there are no data on the association between neck muscle fatigue and headache. Aim To study differences in fatigue characteristics of the neck flexor muscles in adolescents with and without headache. Methods A population-based sample of 17-year-old adolescents with migraine-type headache ( N = 30), tension-type headache ( N = 29) and healthy controls without headache ( N = 30) was examined. Surface EMG data were recorded from the sternocleidomastoid (SCM) muscles bilaterally during an isometric neck flexor endurance test. The spectral median frequency (MF) change during the total endurance time (TMF) and the initial time of 30 s (IMF) was calculated. The intensity of discomfort in the neck area was assessed with the visual analogue scale (VAS). Results The rate of decline in TMF of both SCM muscles was significantly increased in the tension-type headache group compared with controls (right SCM, P = 0.030, OR 2.0, 95% 1.2–3.7; left SCM, P = 0.009, OR 2.5, 95% 1.4–4.9), while no significant differences were found between controls and subjects with migraine. The rate of decline in IMF, the total endurance time ( P = 0.050), and VAS did not differ significantly among the study groups. Conclusions This preliminary finding shows that increased neck flexor muscle fatigue in adolescents seems to be associated with tension-type headache.

Improving Muscle Performance of the Deep Neck Flexors

summary Cervical disorders affect up to 70% of the population and have a recurrence rate of up to 38%. Researchers have reported an association between impaired muscle performance of the deep neck flexors and cervical disorders. The authors present a three stage program designed to improve strength, endurance, and activation of the deep neck flexors that is applicable to the broad athletic population.

PR_197: The Effect of Strengthening Exercise of Deep Neck Flexors on Chronic Neck Pain

Objective: To evaluate the efficacy of strengthening exercise of deep neck flexors in patients with chronic neck pain. Design: Case series. Setting: Rehabilitation outpatient clinic. Participants: 19 patients (age range, 21−61y) with chronic neck pain lasting more than 3 months. Interventions: The strengthening exercise of deep neck flexors was performed 3 sessions a week for 12 weeks. Main Outcome Measures: The visual analog scale (VAS) of pain, Neck Disability Index (NDI), maximum voluntary contractile strength of neck deep flexors, maximum voluntary contractile strength holding time, and submaximal strength holding time. Results: There were significant decreases in VAS, NDI, maximum voluntary contractile strength holding time, and submaximal strength holding time at 6 (P<.05) and 12 weeks (P<.05). And effect of exercise was more favorable at 12 weeks. Conclusions: The strengthening exercise program of the deep neck flexors resulted in reduced neck pain and a decrease in disability of the neck, as well as improved static strength and static endurance of the deep neck flexors.

Reliability of a Measurement of Neck Flexor Muscle Endurance

Neck flexor muscle endurance has been negatively correlated with cervical pain and dysfunction. The purposes of this study were to determine rater reliability in subjects both with and without neck pain and to determine whether there was a difference in neck flexor muscle endurance between the 2 groups. Forty-one subjects with and without neck pain were enrolled in this repeated-measures reliability study. Two raters used an isometric neck retraction test to assess neck flexor muscle endurance for all subjects during an initial session, and subjects without neck pain returned for testing 1 week later. For the group without neck pain, intrarater reliability was good to excellent (intraclass correlation coefficient [ICC(3,1)]=.82-.91), and interrater reliability was moderate to good (ICC[2,1]=.67-.78). The associated standard error of measurement (SEM) ranged from 8.0 to 11.0 seconds and from 12.6 to 15.3 seconds, respectively. For the group with neck pain, interrater reliability was moderate (ICC[2,1]=.67, SEM=11.5). Neck flexor muscle endurance test results for the group without neck pain (mean=38.95 seconds, SD=26.4) and the group with neck pain (mean=24.1 seconds, SD=12.8) were significantly different. Reliability coefficients differed between the 2 groups and ranged from moderate to excellent and improved after the first test session. The interrater reliability of data obtained with the neck flexor muscle endurance test in people with neck pain must be improved in order for clinicians to distinguish a clinically meaningful change from measurement error. Neck flexor muscle endurance was both statistically and clinically greater for subjects without neck pain than for those with neck pain.

Physical impairments in cervicogenic headache: traumatic vs. nontraumatic onset.

In order to quantify the physical impairments associated with different types of headache, 77 subjects belonging to four different groups (postmotor vehicle accident cervicogenic headache subjects, cervicogenic headache subjects nontraumatic, migraine patients and control subjects) were evaluated using the following variables: posture, cervical range of motion, strength of the neck flexors and extensors, endurance of the short neck flexors, manual segmental mobility, proprioception of the neck, and pain (McGill Pain Questionnaire and the skin roll test). The results of this study showed that postmotor vehicle accident cervicogenic patients have significantly limited active cervical range of motion (in flexion/extension and rotations), present decreased strength and endurance of neck flexors and decreased strength of the extensor muscles. Our results suggest that there are enough differences between the postmotor vehicle accident and nontraumatic cervicogenic headache subjects to warrant caution when analysing the data of these two subgroups together, as several studies have done in the past. The onset of headache is therefore an important variable that should be controlled for when attempting to characterize the physical impairments associated with cervicogenic headache.