Localised resistance selectively activates the semispinalis cervicis muscle in patients with neck pain

Is device guided training targeted to the craniocervical flexor and extensor muscles efficacious? A preliminary randomized controlled trial in a cervicogenic headache population

BACKGROUND

Specific neck exercise is effective in the management of cervicogenic headache (CH). The Spinertial device was designed to facilitate craniocervical flexion and extension training, but its efficacy, judged on change in headache impact, has not been tested.

OBJECTIVE

To compare guided and progressive resisted specific neck exercise targeted to the craniocervical flexors and extensors (SNE-fe) performed with Spinertial device to progressive SNE-fe without the device in a cohort with CH.

DESIGN

Randomised controlled trial.

METHODS

Twenty-eight participants with CH were randomly allocated to the Spinertial group (SG) or SNE-fe exercise group without the device (EG). Both groups performed 12 sessions of SNE-fe over six-weeks. The primary outcome was headache impact (HIT-6). Secondary outcomes were the craniocervical flexion test (CCFT), upper cervical (UCS) and lower cervical range of movement, flexion rotation test (FRT) analysed as more or less restricted side (MRS, LRS), the self-reported global rating of change (GROC-scale) and satisfaction with the exercise program (PACES). Outcomes were measured at baseline, post-intervention (T1) and after 1-month (T2).

RESULTS

Significant between-groups differences were found favouring the SG for HIT-6 (T1 p = 0.010, d = 0.5; T2 p < 0.004, d = 0.4), CCFT, UCS ROM, FRT MRS, FRT LRS, PACES and GROC-scale (T1: all p < 0.01; T2: all p < 0.01). Effects sizes were large (>0.8) at T1 and T2. No between-groups differences were found for lower cervical ROM.

CONCLUSION

Training with the Spinertial was more effective than SNE without the device for improving the impact of headache, the endurance of deep neck flexors and UCS ROM in participants with CH.

Effect of long-term cervical extensor exercise program on functional disability, pain intensity, range of motion, cervical muscle mass, and cervical curvature in young adult population with chronic non-specific neck pain: a randomized controlled trial

BACKGROUND

The prevalence of chronic non-specific neck pain (CNNP) is on the rise among the young adult population. We herein aimed to compare the effects of long-term specific cervical extensor training and stretching exercises on improving this chronic disorder in young adults.

METHODS

In this prospective, randomized, controlled study, 70 participants aged 18-35 years with CNNP and cervical lordosis loss were included. The participants were assigned to undergo either specific cervical extensor training (observation group) or perform usual stretching exercises (control group). The exercise duration was set at 12 months, with 9 months at the clinic and 3 months at home. The outcome assessments included changes in the neck disability index, visual analog scale from baseline, cervical range of motion (CROM), cross-sectional areas (CSAs) of cervical extensors, and cervical curvature from baseline. The outcome measures were compared between groups at 3, 6, and 12 months of follow-up.

RESULTS

All 70 participants underwent randomization, and no significant differences in demographics and baseline data were found between the two groups. The observation group showed a greater improvement in neck disability index and visual analog scale scores at the 12-month follow-up than the control group. Additionally, a more substantial increase in CROM and CSAs of cervical extensors was observed in the observation group at the 6-month and 12-month follow-ups (P < 0.05). Although more participants in the observation group achieved cervical lordosis at the 12-month follow-up, the difference was marginally nonsignificant (9% in the control group vs. 28% in the observation group, P = 0.075).

CONCLUSIONS

In young adults with CNNP, long-term specific cervical extensor training was associated with a more significant clinically meaningful improvement in disability, pain, and CROM than stretching exercises. The increased CSAs of cervical extensors may potentially contribute to the restoration of cervical lordosis. Trial registration The study is registered at the Chinese domestic clinical trial (ChiCTR2000040009) at Chictr.org. The date of registration: November 18, 2020.

Exercise therapy including the cervical extensor muscles in individuals with neck pain: A systematic review

OBJECTIVE

To review the use (dosage parameters and combination with other therapeutic interventions) of cervical extensor muscle exercises and their effect on pain, disability (primary outcomes), range of motion, endurance and strength (secondary outcomes) in people with neck pain.

DATA SOURCES

An extensive literature search was conducted through MEDLINE (Ovid), Scopus (Elsevier) and Physiotherapy Evidence Database (PEDro) up to May 2023. The reference lists of all included studies and relevant reviews were screened for additional studies.

REVIEW METHODS

Randomised controlled trials reporting the use of cervical extensor muscle exercises (alone or combined) applied to adults with idiopathic or traumatic neck pain were included. Study selection, data extraction and critical appraisal (PEDro assessment scale) were performed by two blinded reviewers. Data extraction included dosage parameters, other modalities combined with these exercises and outcomes.

RESULTS

Thirty-five randomised controlled trails (eight of which were complementary analyses) with 2409 participants fulfilled the inclusion criteria. Twenty-six were of moderate to high quality. In most studies, cervical extensor muscle exercises were combined with various other therapeutic modalities and applied at different dosages. Only two studies (one high and one low quality) specifically assessed their effectiveness. The high-quality study showed significant improvements in neck pain and disability, pressure point threshold and neck mobility after both low load and high load training for 6 weeks.

CONCLUSION

The results suggest cervical extensor muscle exercises may reduce neck pain and disability; however firm conclusions cannot be drawn because of the few studies that addressed this question and the heterogeneity of the dosage parameters.

Specific versus non-specific exercises for the neck extensor muscles in women with chronic idiopathic neck pain: A randomized controlled trial

BACKGROUND

Structural and functional impairments of the cervical extensor muscles have been demonstrated in people with neck pain. A global exercise approach targeting all neck extensor muscles has shown positive effects in this population. However, to date, the efficacy of exercises specifically targeting the deep neck extensors has neither been tested nor compared to global exercises for the neck extensors.

OBJECTIVES

To compare the effects on pain and disability of a specific lower deep neck extensors (SLDNE) versus a general neck extensor (GNE) exercise program in women with chronic idiopathic neck pain.

METHODS

Fourty-three women with chronic idiopathic neck pain were randomly allocated to either a six-week SLDNE or a GNE exercise program. As primary outcome, neck disability was measured with the Neck Disability Index (NDI). Secondarily, pain intensity (VAS), cervical ROM, pressure pain thresholds (PPTs), cervical and thoracic posture and self-perceived benefit of treatment (GROC) were also measured. Every outcome was measured at baseline and immediately after treatment, except NDI, which was also measured at 6-months follow-up. The GROC was only assessed post-intervention.

RESULTS

Both exercise programs lead to reduced neck disability immediately post-intervention (within-group mean difference [MD] = -6.09; 95% Confidence Interval [CI]: 7.75, -4.42 and -4.73; 95%CI: 6.57, -2.91 respectively) and at the 6-months follow-up (-4.47; 95%CI: 6.41, -2.53 and -4.74; 95%CI: 6.50, -2.97), but with no between group differences. Similar results were found for pain intensity post-intervention, with no between group interaction (within-group MD = -20.87 mm; 95% CI: 28.55, -13.19 and -18.00 mm; 95%CI: (-26.24, -9.76) for SLDNE and GNE groups, respectively). GROC improved after both interventions without any between-group difference.

CONCLUSIONS

A six-week exercise program specifically targeting the lower deep neck extensors lead to comparable outcomes as a general neck extensor exercise program in women with chronic idiopathic neck pain.

Exercise Effects on Neck Function Among F-15E Aircrew

BACKGROUND: Neck pain (NP) is common among high performance aircrew, yet evidence remains insufficient to guide examination, treatment, and prevention. The purpose of this randomized pilot study was to collect baseline data for neck function for F-15E aircrew and determine efficacy and feasibility of two separate exercise protocols in measuring short-term outcomes of subjective and objective neck function in order to inform future study design. METHODS: Randomized to either progressive (PRO) or general (GEN) exercise groups were 41 F-15E aircrew. Data collection occurred at baseline, 3 wk, and 3 mo. RESULTS: At baseline, 39% of the subjects reported current NP, 79.5% reported a history of NP attributed to flying, 12.8% reported being removed from flying duties due to NP, and 10% reported receiving medical care for NP. PRO and GEN group randomization showed similar baseline assessment data. Blinding was successful and exercise logs showed 31.6% compliance with prescribed exercise regimens. There were small but statistically significant increases in neck range of motion in both groups over the course of the study. Aircrew with current NP had significantly higher F-15E flight hours. DISCUSSION: This study supports the high prevalence of NP in aircrew, yet low frequency of seeking care for NP. Future studies to assess NP prevention and treatment in aircrew require an integrated approach that includes operational exercise policy and long-term data collection in flying units with dedicated resources for assessment and analysis. Lee MS, Briggs R, Scheirer V, Kearby G, Young BA. Exercise effects on neck function among F-15E aircrew. Aerosp Med Hum Perform. 2021; 92(10):815824.

Sexual dimorphism of the posterior cervical spine muscle attachments

Cervical spinal injury and neck pain are common disorders with wide physical implications. Neck pain and disability are reported to occur in females more often than in males, and chronic or persistent neck pain after whiplash is twice as common in females. Female athletes also sustain a higher percentage of concussions compared to male athletes. Still, while sexual differences in clinical presentation and outcome are well-established, the underlying etiology for the disparity remains less clear. It is well-established that the origin and insertion landmarks of posterior neck muscles are highly variable, but we do not know if these interindividual differences are associated with sex. Expanding our knowledge on sexual dimorphism in the anatomy of the cervical muscles is essential to our understanding of the possible biomechanical differences between the sexes and hence improves our understanding as to why females suffer from cervical pain more than males. It is also of paramount importance for accurate planning of posterior cervical spine surgery, which cuts through the posterior cervical musculature. Therefore, our main objective is to characterize the anatomy of posterior neck musculature and to explore possible sexual differences in the location of their attachment points. Meticulous posterior neck dissection was performed on 35 cadavers, 19 females, and 16 males. In each specimen, 8 muscle groups were examined bilaterally at 45 osseous anatomical landmarks. Muscles and their attachment sites were evaluated manually then photographed and recorded using Microscribe Digitizer technology built into 3D models. A comparison of attachment landmarks between males and females for each muscle was conducted. Out of the eight muscles that were measured, only two muscles demonstrated significant sex-related anatomical differences-Spinotranversales (splenius capitis and cervicis) and Multifidus. Male Spinotransversales muscle has more attachment points than female. It showed more cranial insertion points in the upper cervical attachments (superior nuchal line, C1 posterior tubercle, and mastoid process) and more caudal insertion points in the spinous processes and transverse processes of the lower cervical and upper thoracic vertebrae. Thus, the male subjects in this study exhibited a greater coverage of the posterior neck both cranially and caudally. Female Multifidus has more attachment points on the spinous processes and articular processes at middle and lower cervical vertebrae and at the transverse processes of the upper thoracic vertebrae. All remaining muscles exhibited no sexual differences. Our findings highlight, for the first time, a sexual dimorphism in attachment points of posterior cervical musculature. It reinforces the notion that the female neck is not a scaled version of the male neck. These differences in muscle attachment could partially explain differences in muscle torque production and range of motion and thus biomechanical differences in cervical spine stabilization between sexes. It sheds a much-needed light on the reason for higher whiplash rates, concussion, and chronic cervical pain among females. Surgeons should take these sexual morphological differences into consideration when deliberating the best surgical approach for posterior cervical surgery.

Cervical Proprioception Impairment in Neck Pain-Pathophysiology, Clinical Evaluation, and Management: A Narrative Review

Neck pain is very common, but most of the causes are unknown, making diagnosis and treatment extremely challenging. Current studies have found that one of the main problems in patients with neck pain is the impairment of cervical proprioception, which subsequently leads to cervical sensorimotor control disturbances. Cervical spine has a very delicate proprioceptive system that plays a crucial role in controlling posture and balance. Cervical proprioceptive impairment in neck pain occurs through a variety of mechanisms. Experimental neck muscle pain induced by injection of hypertonic saline results in inhibition of the activation of painful muscle; chronic neck pain causes structural and functional impairment of cervical muscles; excessive activation of mechanoreceptors in degenerative cervical discs and facet joints produces a large number of erroneous sensory signals. Clinical examinations to assess the link between structural pathology and neck pain have been unsuccessful, opening the way for the development of function-based tests. To date, eight neck sensorimotor control tests have been reported to evaluate patients with chronic neck pain. Although some tests may involve different subsystems (such as oculomotor system and vestibular system), all tests measure sensorimotor control in the neck, and the most commonly used is cervical joint position error (JPE) test. Current studies support the effectiveness of exercises targeting different aspects of sensorimotor function, in particular retraining aimed at improving cervical proprioception and muscle coordination. Based on the available evidence, it is recommended that patients with neck pain should be assessed and managed for cervical proprioceptive impairment and sensorimotor control disturbances.

Ultrasound shear wave elastography measurement of the deep posterior cervical muscles: Reliability and ability to differentiate between muscle contraction states

The deep posterior cervical muscles (DPCM), specifically the semispinalis cervicis and cervical multifidus, are often impaired in patients with neck disorders and have been assessed by several imaging techniques. Prior ultrasound shear wave elastography (SWE) imaging and reliability assessments of the DPCM were performed utilizing similar positioning as assessments for the more superficial cervical extensors. Our objectives were to describe an SWE imaging technique for the DPCM, establish intra-rater reliability of DPCM SWE, and compare DPCM shear modulus during rest and submaximal contraction in both prone and seated positions in individuals without spinal pain. In sixteen participants, the DPCM was located using B-mode ultrasound, then muscle shear modulus was assessed via SWE at both rest and with contraction against a 2-kg resistance applied at the C2 spinous process. Within-day intra-rater reliability was moderate to good (ICC = 0.70-0.88). The DPCM were stiffer during contraction than at rest in the prone position (p = 0.002), and at rest in sitting versus at rest in prone (p = 0.003). Further research is needed to assess DPCM-specific SWE in symptomatic individuals and compare DPCM shear modulus to electromyography across contraction intensities.

Pulsed ND:YAG laser combined with progressive pressure release in the treatment of cervical myofascial pain syndrome: a randomized control trial

[Purpose] To investigate the effect of pulsed Nd:YAG laser combined with the progressive pressure release technique (PPRT) and exercises in the treatment of myofascial trigger points (MTrPs) in patients with myofascial pain syndrome (MPS). [Participants and Methods] A total of 50 patients with MTrPs in the upper trapezius muscle participated in the study. The patients were randomly assigned to two groups and treated with laser plus PPRT (Laser + PPRT group) or placebo laser and exercises (PL + PPRT group). The laser was applied for eight MTrPs with a 50 J/point. PPRT was applied for 30 seconds for each point. Exercises included strengthening and stretching exercises applied three times per week for four weeks. A visual analogue scale (VAS) and pressure pain threshold (PPT) were used to measure pain and pain threshold, respectively. A cervical range of motion device (CROM) was used to measure the cervical range of motion. [Results] Both treatment groups showed significant improvement in CROM, PPT, and VAS post-treatment with a more significant effect in the Laser + PPRT group compared to the PL + PPRT group. [Conclusion] PPRT and exercises alone or that in combination with laser therapy were effective in the treatment of active MTrPs in patients with MPS.

Asymmetric atrophy of cervical multifidus muscles in patients with chronic unilateral cervical radiculopathy

The purpose of this study was to assess whether the asymmetry of cervical multifidus muscles occurred in radiculopathy patients, and if it did, whether it was related to the chronicity of unilateral cervical radiculopathy by assessing the cross-sectional area (CSA) of multifidus muscles using magnetic resonance imaging (MRI).This study used a retrospective design and was conducted from January 2013 to August 2016. Seventy-seven patients (age 18-65) who had unilateral neck pain, symptom duration of 3 months to 1 year, and who were diagnosed with unilateral 6th cervical radiculopathy by electrodiagnostic testing, were included in study. The CSA of cervical multifidus muscles was measured at the midpoint between the lower margin of the upper vertebra and upper margin of the lower vertebra on axial MRI. Relative CSA (rCSA), which is the ratio of the CSA of muscles to that of the lower margin of C5 vertebra was also obtained.At the C4-5 and C6-7 levels, CSA and rCSA of cervical multifidus muscles showed no statistically difference between the affected and unaffected sides. At the C5-6 level, multifidus muscles were significantly smaller in the affected side (at the C5-6 level, P value of CSA.007 and P value of rCSA.102).The atrophy of multifidus muscles ipsilateral to cervical radiculopathy was observed in patients who had chronic unilateral cervical radiculopathy.

Effect of specific deep cervical muscle exercises on functional disability, pain intensity, craniovertebral angle, and neck-muscle strength in chronic mechanical neck pain: a randomized controlled trial

Background

Exercise is known to be an important component of treatment programs for individuals with neck pain. The study aimed to compare the effects of semispinalis cervicis (extensor) training, deep cervical flexor (flexor) training, and usual care (control) on functional disability, pain intensity, craniovertebral (CV) angle, and neck-muscle strength in chronic mechanical neck pain.

Methods

A total of 54 individuals with chronic mechanical neck pain were randomly allocated to three groups: extensor training, flexor training, or control. A Thai version of the Neck Disability Index, numeric pain scale (NPS), CV angle, and neck-muscle strength were measured at baseline, immediately after 6 weeks of training, and at 1- and 3 -month follow-up.

Results

Neck Disability Index scores improved significantly more in the exercise groups than in the control group after 6 weeks training and at 1- and 3-month follow-up in both the exten-sor (P=0.001) and flexor groups (P=0.003, P=0.001, P=0.004, respectively). NPS scores also improved significantly more in the exercise groups than in the control group after 6 weeks’ training in both the extensor (P<0.0001) and flexor groups (P=0.029. In both exercise groups, the CV angle improved significantly compared with the control group at 6 weeks and 3 months (extensor group, P=0.008 and P=0.01, respectively; flexor group, P=0.002 and 0.009, respectively). At 1 month, the CV angle had improved significantly in the flexor group (P=0.006). Muscle strength in both exercise groups had improved significantly more than in the control group at 6 weeks and 1- and 3-month follow-up (extensor group, P=0.04, P=0.02, P=0.002, respectively; flexor group, P=0.002, P=0.001, and 0.001, respectively). The semispinalis group gained extensor strength and the deep cervical flexor group gained flexor strength.

Conclusion

The results suggest that 6 weeks of training in both exercise groups can improve neck disability, pain intensity, CV angle, and neck-muscle strength in chronic mechanical neck pain.

Trial registration

NCT02656030

Activation of the semispinalis cervicis and splenius capitis with cervical pulley exercises

STUDY DESIGN

Quasi-Experimental.

OBJECTIVE

To assess the activation of semispinalis cervicis (d-SSC) and splenius capitis (s-SC) muscles, and the activation between the two during neck pulley and free weight exercises.

BACKGROUND

Altered activation of cervical extensors may occur with neck pain, suggesting that exercises should be designed to target these muscles.

METHODS

d-SSC and s-SC activity was recorded unilaterally with intramuscular electromyography from healthy volunteers during cervical isometric exercises: 1) extension with a pulley rope angled from incline to vertical, 2) extension with right, left and central forehead hanging weight, and 3) rotation with pulley rope angled from incline to decline.

RESULTS

Extension against a vertical force led to greater activation of d-SSC (P < 0.001) and s-SC (P < 0.001) compared to the inclined, declined and horizontal pulley. With each of these conditions, amplitude of muscle activity was higher for the d-SSC compared to the s-SC muscle (P < 0.0001). Extension with free weight hanging on right, left or central forehead, showed no differences across conditions, although in each condition, the d-SSC amplitude was higher than the s-SC. For cervical rotation, the declined pulley led to the greatest activation of both muscles (P < 0.05). Higher levels of activity were observed for the s-SC compared to the d-SSC (P < 0.01) for all rotation conditions.

CONCLUSION

A vertical resistance during an extension exercise or a declined resistance during cervical rotation, increased neck extensor activation. The results from this preliminary study provide guidance for future work on the exploration and development of low-load exercise design for patients with neck pain disorders.

Neck and shoulder muscle activity and posture among helicopter pilots and crew-members during military helicopter flight

Neck pain among helicopter pilots and crew-members is common. This study quantified the physical workload on neck and shoulder muscles using electromyography (EMG) measures during helicopter flight. Nine standardized sorties were performed, encompassing: cruising from location A to location B (AB) and performing search and rescue (SAR). SAR was performed with Night Vision Goggles (NVG), while AB was performed with (AB+NVG) and without NVG (AB-NVG). EMG was recorded for: trapezius (TRA), upper neck extensors (UNE), and sternocleido-mastoid (SCM). Maximal voluntary contractions (MVC) were performed for normalization of EMG (MVE). Neck posture of pilots and crew-members was monitored and pain intensity of neck, shoulder, and back was recorded. Mean muscle activity for UNE was ∼10% MVE and significantly higher than TRA and SCM, and SCM was significantly lower than TRA. There was no significant difference between AB-NVG and AB+NVG. Muscle activity in the UNE was significantly higher during SAR+NVG than AB-NVG. Sortie time (%) with non-neutral neck posture for SAR+NVG and AB-NVG was: 80.4%, 74.5% (flexed), 55.5%, 47.9% (rotated), 4.5%, 3.7% (lateral flexed). Neck pain intensity increased significantly from pre- (0.7±1.3) to post-sortie (1.6±1.9) for pilots (p=0.028). If sustained, UNE activity of ∼10% MVE is high, and implies a risk for neck disorders.

Can neck exercises enhance the activation of the semispinalis cervicis relative to the splenius capitis at specific spinal levels?

The deep cervical extensor, semispinalis cervicis, displays changes in behaviour and structure in people with chronic neck pain yet there is limited knowledge on how activation of this muscle can be emphasized during training. Using intramuscular electromyography (EMG), this study investigated the activity of the deep semispinalis cervicis and the superficial splenius capitis muscle at two spinal levels (C2 and C5) in ten healthy volunteers during a series of neck exercises: 1. Traction and compression, 2. Resistance applied in either flexion or extension at the occiput, at the level of the vertebral arch of C1 and of C4, and 3. Maintaining the neck in neutral while inclined on the elbows, with and without resistance at C4. The ratio between semispinalis cervicis and the splenius capitis EMG amplitude was quantified as an indication of whether the exercise could emphasize the activation of the semispinalis cervicis muscle relative to the splenius capitis. Manual resistance applied in extension over the vertebral arch emphasized the activation of the semispinalis cervicis relative to the splenius capitis at the spinal level directly caudal to the site of resistance (ratio: 2.0 ± 1.1 measured at C5 with resistance at C4 and 2.1 ± 1.2 measured at C2 with resistance at C1). This study confirmed the possibility of emphasizing the activation of the semispinalis cervicis relative to the splenius capitis which may be relevant for targeted exercise interventions for this deep extensor muscle. Further studies are required to investigate the clinical efficacy of these exercises for people with neck pain.