Influence of neck pain on cervical movement in the sagittal plane during smartphone use

[Purpose] Smartphone use reportedly changes posture. However, how neck posture is altered in smartphone users with neck pain is unknown. This study examined changes in the posture of young adults with and without mild neck pain (MNP) when using a smartphone. [Subjects] Thirteen control subjects and 14 subjects with MNP who used smartphones were recruited. [Methods] The upper cervical (UC) and lower cervical (LC) angles in the sagittal plane were measured using an ultrasound-based motion analysis system while the seated subjects used a smartphone for 5 min. [Results] During smartphone use, the MNP group exhibited greater UC and LC flexion angles than the control group. [Conclusion] These findings suggest that young adults with MNP are more careful and more frequently utilize a neutral neck posture than young adults without MNP when using a smartphone while sitting.Key words: Smartphone, Cervical flexion, Young adult     

Altered Co-contraction of Cervical Muscles in Young Adults with Chronic Neck Pain during Voluntary Neck Motions

[Purpose] Muscle co-contraction is important in stabilizing the spine. The aim of this study was to compare cervical muscle co-contraction in adults with and without chronic neck pain during voluntary movements. [Subjects and Methods] Surface electromyography of three paired cervical muscles was measured in fifteen young healthy subjects and fifteen patients with chronic neck pain. The subjects performed voluntary neck movements in the sagittal and coronal plane at slow speed. The co-contraction ratio was defined as the normalized integration of the antagonistic electromyography activities divided by that of the total muscle activities. [Results] The results showed that the co-contraction ratio of patients was greater during flexion movement, lesser during extension movement, slightly greater during right lateral bending, and slightly lesser during left lateral bending compared with in the controls. [Conclusion] The results suggested that neck pain patients exhibit greater antagonistic muscle activity during flexion and dominate-side bending movements to augment spinal stability, while neuromuscular control provides relatively less protection in the opposite movements. This study helps to specify the changes of the stiffness of the cervical spine in neck pain patients and provides a useful tool and references for clinical assessment of neck disorders.Key words: Co-contraction, Chronic neck pain, Electromyography     

Comparison of the Lumbar Flexion Angle and EMG Activity in Trunk Muscles in Individuals with and without Limited Hip Flexion Range of Motion during Visual Display Terminal Work with Cross-Legged Sitting

[Purpose] The purpose of this study was to compare the lumbar flexion angle and electromyography (EMG) measurements of trunk muscle activity in individuals with and without limited hip flexion range of motion (ROM) during visual display terminal (VDT) work with cross-legged sitting. [Subjects] The 15 participants included a control group with sufficient hip flexion ROM (n = 7) and an experimental group with limited hip flexion ROM (n = 8). [Methods] All subjects performed VDT work with cross-legged sitting. The lumbar flexion angle was measured using a three-dimensional motion capture system, and the trunk muscle activity was recorded using a surface EMG system during VDT work with cross-legged sitting. The differences in trunk flexion angle and trunk muscle activity between the two groups were analyzed using independent t-tests. [Results] The lumbar flexion angle was significantly greater in the experimental group than the control group, although trunk muscle activity did not differ between the two groups. [Conclusion] These findings suggest that limited hip flexion leads to greater lumbar flexion during cross-legged sitting.Key words: Cross-legged sitting, Electromyography, Lumbar flexion     

An exploratory study on the impact of static and dynamic sitting postures on lumbar and pelvic mobility during visual display terminal work

[Purpose] Limited studies exist on the impact of sustained work at a visual display terminal (VDT) on the position and motion of the pelvis and lumbar spine. We evaluated the changes in movement of the lumbar column and pelvis during VDT work. [Participants and Methods] We evaluated the sitting posture of 20 healthy adults while they performed VDT work. The effects of the sitting posture on lumbo-pelvic position and motion were captured using a three-dimensional accelerometer. Between-posture effects of VDT work were evaluated using an analysis of variance (ANOVA). A two-way ANOVA was used to assess the root mean square (RMS) values of the 80-min VDT work period for each posture. A one-way ANOVA was used to evaluate pre- and post-work changes in RMS values during the finger floor distance test (FFD). [Results] People in the dynamic sitting balance chair (DSBC)-based posture demonstrated significantly higher pelvic RMS values than those in reclining and upright sitting postures. The DSBC-based posture was also associated with significantly higher pre- and post-work lumbar and pelvic RMS values during the FFD than in the reclining and upright sitting postures. [Conclusion] The dynamic balance chair may be an effective method of establishing a pattern of spinal exercise during prolonged sitting.Key words: Dynamic sitting posture, Visual display terminal, Acceleration sensor     

Neck kinematics and sternocleidomastoid muscle activation during neck rotation in subjects with forward head posture

[Purpose] The present study investigated differences in the kinematics of the neck and activation of the sternocleidomastoid (SCM) muscle during neck rotation between subjects with and without forward head posture (FHP). [Subjects and Methods] Twenty-eight subjects participated in the study (14 with FHP, 14 without FHP). Subjects performed neck rotation in two directions, left and right. The kinematics of rotation-lateral flexion movement patterns were recorded using motion analysis. Activity in the bilateral SCM muscles was measured using surface electromyography. Differences in neck kinematics and activation of SCM between the groups were analyzed by independent t-tests. [Results] Maintaining FHP increased the rotation-lateral flexion ratio significantly in both directions. The FHP group had significantly faster onset time for lateral flexion movement in both directions during neck rotation. Regarding the electromyography of the SCM muscles during neck rotation in both directions, the activity values of subjects with FHP were greater than those of subjects without FHP for the contralateral SCM muscles. [Conclusion] FHP can induce changes in movement in the frontal plane and SCM muscle activation during neck rotation. Thus, clinicians should consider movement in the frontal plane as well as in the sagittal plane when assessing and treating patients with forward head posture.Key words: Axial rotation, Cervical movement, Forward head posture     

The Effect of a New Neck Support Tying Method Using Thera-Band on Cervical ROM and Shoulder Muscle Pain after Overhead Work

[Purpose] This study proposed a new neck support tying (NST) method using Thera-Band for the prevention of neck and shoulder pain in workers doing overhead work. The purpose of this study was to investigate the effect of the new NST method using Thera-Band on cervical ROM and shoulder pain after overhead work. [Subjects] Fourteen male subjects were recruited. [Methods] This study measured the cervical ROM and pressure pain threshold (PPT) of the upper and middle trapezius (UT and MT) muscles after the control and NST groups had performed overhead work. [Results] The cervical flexion, extension, and lateral flexion angles of the NST group were significantly larger than those of the control group. The PPTs of UT and MT of the NST group were significantly higher than those of the control group [Conclusion] The NST prevented ROM reduction and pain in the cervical and shoulder regions.Key words: Neck supporter, Overhead work, Thera-Band     

Immediate effects of dynamic sitting exercise on the lower back mobility of sedentary young adults

[Purpose] The aim of this study was to investigate the effects of dynamic sitting exercises during prolonged sitting on the lower back mobility of sedentary young adults. [Subjects and Methods] Seventy-one subjects aged between 18–25 years participated in this study. Following a randomized crossover study design, subjects were randomly assigned to two groups: sitting only and dynamic sitting exercise. The dynamic sitting exercise was a combination of lower back hyperextension and abdominal drawing-in movements which were repeated 6 times in a 1-minute period and performed every 20 minutes during a 2-hour sitting session. Lumbar range of movement was measured with the modified-modified Schober test, and the pain intensity was evaluated using the visual analog scale. [Results] After the experiment, the lumbar range of movement was significantly impaired in the sitting only group; however, it was significantly improved in the dynamic sitting exercise group. There were significant differences in lumbar range of movement of both flexion and extension between the groups. No significant difference in pain intensity between the groups was found. [Conclusion] These results suggest that dynamic sitting exercises during prolonged sitting can prevent decreases in lumbar range of movement in both back flexion and extension following a 2-hour sitting period.Key words: Back exercise, Flexibility, Long sitting     

A Comparison of the Deep Cervical Flexor Muscle Thicknesses in Subjects with and without Neck Pain during Craniocervical Flexion Exercises

[Purpose] The purpose of the present study was to examine the amount of change in the thicknesses of the deep cervical flexor (DCF) and sternocleidomastoid (SCM) muscles in subjects with neck pain and subjects without neck pain during craniocervical flexion exercise (CCFE). [Subjects] The total number of subjects was 40, comprising 20 in the no-pain group (males 11, females 9) and 20 in the pain group (males 8, females 12). [Methods] Muscle images were obtained using ultrasound, and the thicknesses of the individual muscles were measured using the NIH ImageJ software. [Results] During CCFE, as pressure increased, the no-pain group recruited the DCF more than the pain group, while the pain group recruited the SCM more. [Conclusion] Selective DCF contraction exercises are considered very useful in the treatment of patients with neck pain.Key words: Craniocervical flexion exercise, Deep cervical flexor, Sternocleidomastoid     

Effects of the active release technique on pain and range of motion of patients with chronic neck pain

[Purpose] To compare the influences of the active release technique (ART) and joint mobilization (JM) on the visual analog scale (VAS) pain score, pressure pain threshold (PPT), and neck range of motion (ROM) of patients with chronic neck pain. [Subjects] Twenty-four individuals with chronic neck pain were randomly and equally assigned to 3 groups: an ART group, a joint mobilization (JM) group, and a control group. Before and after the intervention, the degree of pain, PPT, and ROM of the neck were measured using a VAS, algometer, and goniometer, respectively. [Results] The ART group and JM group demonstrated significant changes in VAS and ROM between pre and post-intervention, while no significant change was observed in the control group. Significant differences in the PPT of all muscles were found in the ART group, while significant differences in all muscles other than the trapezius were found in the JM group. No significant difference in PPT was observed in any muscle of the control group. The posthoc test indicated no statistically significant difference between the ART and JM group, but the differences of variation in VAS, PPT, and ROM were greater in the ART group than in the JM and control groups. [Conclusion] ART for the treatment of chronic neck pain may be beneficial for neck pain and movement.Key words: Active release technique, Soft tissue, Chronic neck pain     

Correlation between Intrinsic Patellofemoral Pain Syndrome in Young Adults and Lower Extremity Biomechanics

[Purpose] The purpose of this study was to evaluate the correlation between intrinsic patellofemoral pain syndrome (PFPS) in young adults and lower extremity biomechanics. [Subjects] This experiment was carried out with sixty (24 men and 32 women), who are normal university students as subjects. [Methods] All subjects underwent 3 clinical evaluations. For distinguishing the intrinsic PFPS from controls, we used the Modified Functional Index Questionnaire (MFIQ), Clarke’s test and the Eccentric step test. Based on the results of the tests, subjects who were classified as positive for 2 more tests were allocated to the bilateral or unilateral intrinsic PFPS group (n=14), and the others were allocated to the control group (n=42). These two groups were tested for hamstring tightness, foot overpronation, and static Q-angle and dynamic Q-angle. These are the four lower extremity biomechanic, cited as risk factors of patellofemoral pain syndrome. [Results] The over pronation, static Q-angle and the dynamic Q-angle were not significantly different between the two groups. However, the hamstring tightness of the PFPS group was significantly greater than that of the controls. [Conclusion] We examined individuals for intrinsic patellofemoral pain syndrome in young adults and lower extremity biomechanics. We found a strong correlation between intrinsic PFPS and hamstring tightness.Key words: Hamstring, Patellofemoral, Pain     

Effects of Cervical Flexion on the Flexion-relaxation Ratio during Smartphone Use

[Purpose] The purpose of this study was to measure the cervical flexion-relaxation ratio (FRR) and intensity of neck pain and identify the differences according to postures adopted while using smartphones. [Subjects] Fifteen healthy adults with no neck pain, spinal trauma, or history cervical surgery participated in this study. [Methods] The activity of the cervical erector spinae muscle was recorded while performing a standardized cervical flexion-extension movement in three phases (flexion, sustained full flexion, extension). And neck pain intensity was recorded using a visual analog scale (VAS) with values between 0 and 10. Postures held while using a smartphone are distinguished between desk postures and lap postures. The FRR was calculated by dividing the maximal muscle activation during the extension phase by average activation during the complete flexion phase. [Results] No significant differences were found in the FRR between desk posture, lap posture, and baseline, though the intensity of the neck pain increased in the lap posture. [Conclusion] The FRR could be a significant criterion of neuromuscular impairment in chronic neck pain or lumbar pain patients, but it is impossible to distinguish neck pain that is caused by performing task for a short time. Prolonged lap posture might cause neck pain, so the use of smartphones for a long time in this posture should be avoided.Key words: Smartphone, Cervical flexion-relaxation ratio, Electromyography     

The Effects of Thoracic Manipulation Versus Mobilization for Chronic Neck Pain: a Randomized Controlled Trial Pilot Study

[Purpose] To investigate effects of thoracic manipulation versus mobilization on chronic neck pain. [Methods] Thirty-nine chronic neck pain subjects were randomly assigned to single level thoracic manipulation, single level thoracic mobilization, or a control group. The cervical range of motion (CROM) and pain ratings (using a visual analog scale: VAS) were measured before, immediately after and at a 24-hour follow-up. [Results] Thoracic manipulation significantly decreased VAS pain ratings and increased CROM in all directions in immediate and 24-hour follow-ups. The thoracic mobilization group significantly increased in CROM in most directions at immediate follow-up and right and left rotational directions at the 24-hour follow-up. Comparisons between groups revealed the CROM for the manipulation group to increase significantly more than for control subjects in most directions at immediate follow-up and flexion, left lateral flexion and left rotation at the 24-hour follow-up. The CROM for the thoracic mobilization group significantly increased in comparison to the control group in flexion at immediate follow-up and in flexion and left rotation at the 24-hour follow-up. [Conclusion] The study demonstrated reductions in VAS pain ratings and increases in CROM at immediate and 24-hour follow-ups from both single level thoracic spine manipulation and thoracic mobilization in chronic neck pain.Key words: Single level thoracic manipulation, Single level thoracic mobilization, Chronic neck pain     

The effects of a neck musculoskeletal intervention on neck pain levels and depression in post-traumatic stress disorder patients

[Purpose] To identify the effects of a neck intervention on neck pain and depression in patients with post-traumatic stress disorder (PTSD). [Subjects] Thirty-one patients with neck pain and a diagnosis of PTSD were enrolled. [Methods] Neck exercise training was performed with the experimental group and neck self-exercise (using a modification of the McKenzie exercise) was used with the control group. Both groups performed their exercises for 30 minutes at a time, three times per week. To compare the effects of the interventions, the threshold of neck tenderness and depression levels were measured at each period. [Results] The pain threshold of both sides of the trapezius showed a significant difference between the two groups at the three measurement periods. In the experimental group, the threshold increased by 19.7% on the left and 18.3% on the right after the intervention compared to before. Depression levels significantly differed in the experimental group between the three measurements. [Conclusion] This study has important implications for therapeutic strategies, as it provides strong evidence for a method of improving symptoms of neck pain; furthermore, it is effective for subjects with psychological problems such as PTSD.Key words: Post-traumatic stress disorder, Neck pain, Depression     

Does proprioceptive system stimulation improve sit-to-walk performance in healthy young adults?

[Purpose] Sit-to-walk performance is linked to proper proprioceptive information processing. Therefore, it is believed that an increase of proprioceptive inflow (using muscle vibration) might improve sit-to-walk performance. However, before testing muscle vibration effects on a frail population, assessment of its effects on healthy young people is necessary. Thus, the aim of this study was to investigate the effects of muscle vibration on sit-to-walk performance in healthy young adults. [Subjects and Methods] Fifteen young adults performed the sit-to-walk task under three conditions: without vibration, with vibration applied before movement onset, and with vibration applied during the movement. Vibration was applied bilaterally for 30 s to the tibialis anterior, rectus femoris, and upper trapezius muscles bellies. The vibration parameters were as follows: 120 Hz and 1.2 mm. Kinematics and kinetic data were assessed using a 3D motion capture system and two force plates. The coordinates of reflective markers were used to define the center-of-mass velocities and displacements. In addition, the first step spatiotemporal variables were assessed. [Results] No vibration effect was observed on any dependent variables. [Conclusion] The results show that stimulation of the proprioceptive system with local muscle vibration does not improve sit-to-walk performance in healthy young adults.     

The effect of neurac training in patients with chronic neck pain

[Purpose] This study aimed to investigate the effects of neurac training on pain, function, balance, fatigability, and quality of life. [Subjects and Methods] Subjects with chronic neck pain who were treated in S hospital were included in this study; they were randomly allocated into two groups, i.e., the experimental group (n = 10) and the control group (n = 10). Both groups received traditional physical therapy for 3 sessions for 30 min per week for 4 weeks. The experimental group practiced additional neurac training for 30 min/day, for 3 days per week for 4 weeks. All subjects were evaluated using the visual analogue scale (VAS), the neck disability index (NDI), the biorescue (balance), the questionnaire for fatigue symptoms (fatigue), and the medical outcome 36-item short form health survey (SF-36) pre- and post-intervention. [Results] The experimental group effectively improved their pain, function, balance, fatigability, and quality of life. [Conclusion] Neurac training is thus considered an effective training program that enhances body functionality by improving pain, function, balance ability, fatigability, and quality of life in patients with chronic neck pain.Key words: Chronic neck pain, Sling-neurac training, Function     

Movement behaviour in patients with chronic neck pain

Background and Purpose. The present study evaluated whether patients with chronic neck pain demonstrate characteristic angular movement deviations during repeated cervical spine movements. Method. Sixteen patients with chronic neck pain and a group of 18 aged‐matched healthy control subjects performed 10 repetitive maximal cervical movement cycles (flexion/extension, rotation, lateral flexion) at a self‐determined velocity. To collect the kinematic data of the cervical spine, a three‐dimensional ultrasonic movement analysis system (Zebris CMS70^©, Germany) was used. To describe the movement variability in the maximum oscillation amplitudies the intra‐subject coefficients of variation (CV %) was calculated. The maximum difference was characterized by the absolute differences between the minimum and maximum oscillation amplitudes of iterated movement cycles. Pain intensity was obtained by visual analogue scales (VAS). Results. The average pain rating of the patients with chronic neck pain indicated moderate neck pain intensity (3.7 (±0.8)). Independent Student's t‐tests revealed a significantly decreased range of movement (ROM) in the chronic neck pain group for all anatomic values (p < 0.05), except for the lateral flexion to the right. The maximum differences and variability parameters showed significantly increased values in the chronic neck pain group in all directions (p < 0.001). Conclusion. Maximal cervical ROM was significantly lower, and movement variability was significantly higher, in patients compared with healthy control subjects. The differences of cervical motion variability point towards increased movement irregularities in patients with chronic neck pain. The present study shows evidence to support the hypothesis that additional information may be gained from the analysis of movement variability. Copyright © 2007 John Wiley & Sons, Ltd.     

Differences in onset time between the vastus medialis and lateralis during stair stepping in individuals with genu varum or valgum

[Purpose] We investigated the difference in onset time between the vastus medialis and lateralis according to knee alignment during stair ascent and descent to examine the effects of knee alignment on the quadriceps during stair stepping. [Subjects] Fifty-two adults (20 with genu varum, 12 with genu valgum, and 20 controls) were enrolled. Subjects with > 4 cm between the medial epicondyles of the knees were placed in the genu varum group, whereas subjects with > 4 cm between the medial malleolus of the ankle were placed in the genu valgum group. [Methods] Surface electromyography was used to measure the onset times of the vastus medialis and vastus lateralis during stair ascent and descent. [Results] The vastus lateralis showed more delayed firing than the vastus medialis in the genu varum group, whereas vastus medialis firing was more delayed than vastus lateralis firing in the genu valgum group. Significant differences in onset time were detected between stair ascent and descent in the genu varum and valgum groups. [Conclusion] Genu varum and valgum affect quadriceps firing during stair stepping. Therefore, selective rehabilitation training of the quadriceps femoris should be considered to prevent pain or knee malalignment deformities.Key words: Quadriceps muscle, Genu varum, Genu valgum     

Determine the effect of neck muscle fatigue on dynamic visual acuity in healthy young adults

[Purpose] The aim of this study was to determine whether neck muscle fatigue affects dynamic visual acuity in healthy young participants. [Subjects and Methods] This study was a double-blinded, prospective, randomized, controlled trial. Thirty healthy young subjects (ages 21 to 30 years) participated in the study. Participants were randomly divided into an experimental group (n=15) and a control group (n=15). The experimental group performed an exercise designed to induce neck muscle fatigue and the control group preformed non-fatiguing sham exercises. [Results] There were significant differences in mean dynamic visual acuity between the two groups (0.26±0.11 LogMar versus 0.003±0.02 LogMar). Subjects in the experimental group showed a significant decline in their dynamic visual acuity compared with the control group. Dynamic visual acuity strongly correlated with neck muscle fatigue (r = 0.79). No significant differences in joint position error were observed between the two groups and no significant correlations between joint position error and neck muscle fatigue were observed (r = 0.23). [Conclusion] The results of this study suggest that neck muscle fatigue negatively impacts dynamic visual acuity. Although not statistically significant, cervical spine proprioception as measured by the joint position error in the experimental group was diminished after fatigue.Key words: Dizziness, Cervical vertigo     

Cervicocephalic kinesthetic sensibility in young and middle-aged adults with or without a history of mild neck pain

Previous research has shown that there is no significant relationship between the degree of structural degeneration of the cervical spine and neck pain. We therefore sought to investigate the potential role of sensory dysfunction in chronic neck pain. Cervicocephalic kinesthetic sensibility, expressed by how accurately an individual can reposition the head, was studied in three groups of individuals, a control group of 20 asymptomatic young adults and two groups of middle-aged adults (20 subjects in each group) with or without a history of mild neck pain. An ultrasound-based three-dimensional coordinate measuring system was used to measure the position of the head and to test the accuracy of repositioning. Constant error (indicating that the subject overshot or undershot the intended position) and root mean square errors (representing total errors of accuracy and variability) were measured during repositioning of the head to the neutral head position (Head-to-NHP) and repositioning of the head to the target (Head-to-Target) in three cardinal planes (sagittal, transverse, and frontal). Analysis of covariance (ANCOVA) was used to test the group effect, with age used as a covariate. The constant errors during repositioning from a flexed position and from an extended position to the NHP were significantly greater in the middle-aged subjects than in the control group (beta=0.30 and beta=0.60, respectively; P<0.05 for both). In addition, the root mean square errors during repositioning from a flexed or extended position to the NHP were greater in the middle-aged subjects than in the control group (beta=0.27 and beta=0.49, respectively; P<0.05 for both). The root mean square errors also increased during Head-to-Target in left rotation (beta=0.24;P<0.05), but there was no difference in the constant errors or root mean square errors during Head-to-NHP repositioning from other target positions (P>0.05). The results indicate that, after controlling for age as a covariate, there was no group effect. Thus, age appears to have a profound effect on an individual's ability to accurately reposition the head toward the neutral position in the sagittal plane and repositioning the head toward left rotation. A history of mild chronic neck pain alone had no significant effect on cervicocephalic kinesthetic sensibility.     

Effects of the CORE Exercise Program on Pain and Active Range of Motion in Patients with Chronic Low Back Pain

[Purpose] This study aimed to identify the effects of the CORE exercise program on pain and active range of motion (AROM) in patients with chronic low back pain. [Subjects and Methods] Thirty subjects with chronic low back pain were randomly allocated to two groups: the CORE group (n = 15) and the control group (n = 15). The CORE group performed the CORE exercise program for 30 minutes a day, 3 times a week, for 4 weeks, while the control group did not perform any exercise. The visual analog scale (VAS) and an algometer were used to measure pain, and pain-free AROM in the trunk was measured before and after the intervention. [Results] The CORE group showed significantly decreased VAS scores at rest and during movement and had a significantly increased pressure pain threshold in the quadratus lumborum and AROM in the trunk compared with those in the control group. [Conclusion] This study demonstrated that the CORE exercise program is effective in decreasing pain and increasing AROM in patients with chronic low back pain. Thus, the CORE exercise program can be used to manage pain and AROM in patients with chronic low back pain.Key words: CORE exercise program, Chronic low back pain (CLBP), Active range of motion (AROM)