Decreased thickness of the lower trapezius muscle in patients with unilateral neck pain

Impact of structural factors around the accessory nerve on the pathogenesis of essential neck and upper-back stiffness: a sonographic investigation

INTRODUCTION

Neck and upper-back stiffness involves discomfort/ache in the trapezius muscle (TM). The pathogenesis of 'essential neck and upper-back stiffness' without obvious causes remains uncertain. In symptomatic subjects, TM hardness correlates with decreased transverse cervical artery (TCA) blood flow to the TM. Neck and upper-back stiffness could be associated with both hemodynamic and neurological factors affecting the TM. We therefore sonographically evaluated structural factors around the accessory nerve innervating the TM impacting neck and upper-back stiffness.

METHODS

Participants comprised 69 healthy young adults (33 men, 36 women; 21 ± 1 y) who completed questionnaires and underwent elastography to determine TM hardness as a strain ratio and pulsed Doppler sonography to determine TCA hemodynamics. Intermuscular length was measured as the distance between sternocleidomastoid and levator scapulae muscles around the accessory nerve. Relationships of intermuscular length with symptoms, TM hardness, and TCA hemodynamics were analyzed.

RESULTS

Intermuscular length was greater in symptomatic subjects (median 2.3 mm, interquartile range 1.5-3.1 mm) than in asymptomatic subjects (median 1.8 mm, interquartile range 1.5-2.3 mm; p = 0.032). Intermuscular length correlated positively with symptom severity (r = 0.43, p = 0.014) and negatively with strain ratio for the TM (r = -0.39, p = 0.025) and peak systolic velocity in the TCA (r = -0.40, p = 0.022). Intermuscular length contributed independently to the presence of symptoms (p = 0.025, odds ratio 2.26, 95% confidence interval 1.11-4.62).

CONCLUSION

In symptomatic subjects, symptom severity, TM hardness and TCA hemodynamics all correlated with greater intermuscular length. Structures around the accessory nerve could be associated with the pathogenesis of essential neck and upper-back stiffness.

Differences on lower trapezius pressure pain threshold, muscle strength and muscle thickness in individuals with chronic neck pain and active or latent myofascial triggers points

BACKGROUND

Myofascial trigger points (MTrPs) in the lower trapezius have been recognized as an important source of neck pain. This study aims to compare the lower trapezius muscle strength, pressure pain threshold (PPT) and muscle thickness at rest and contraction between participants and painful vs. no-painful side with active and latent MTrPs; and to examine the associations among these variables with pain intensity, duration and disability in patients with neck pain.

METHODS

A cross-sectional study was carried out in 64 people with neck pain with active or latent MTrPs (34 Active MTrPs group and 30 Latent MTrPs groups). Muscle strength, pressure pain threshold and muscle thickness at rest and contraction of the lower trapezius was recorded.

RESULTS

No significant differences were found in descriptive data, dominant side, or side of neck pain. However, the Active MTrPs Group had lower pain pressure thresholds (PPT) on the neck pain side compared to the Latent MTrPs Group, indicating greater sensitivity. Muscle thickness and strength showed minor differences between groups. Pain intensity correlated moderately with pain duration and strongly with neck pain disability.

CONCLUSIONS

The results of the present study showed differences in PPT on the lower trapezius muscle in active and latent MTrP in neck side pain compared to non-neck side pain. In addition, lower trapezius strength reported differences between the neck side pain compared to non-neck side pain in both active and latent MTrP. Lower trapezius muscle strength showed significant moderate association with muscle thickness at contraction.

Effects of scapular treatment on chronic neck pain: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Chronic neck pain (CNP) is a common public health problem that affects daily living activities and quality of life. There is biomechanical interdependence between the neck and scapula. Studies have shown that shoulder blade function might be related to chronic neck pain. We therefore evaluated the effects of scapular targeted therapy on neck pain and function in patients with CNP.

METHODS

Databases, including MEDLINE (via PubMed), EMBASE (via Ovid), Ovid, Web of Science, and Scopus, were systematically searched for randomized controlled trials published in English investigating treatment of the scapula for CNP before July 16, 2023.

RESULTS

A total of 313 participants were included from 8 RCTs. Compared with those in the control group, the intervention in the scapular treatment group exhibited greater improvement in pain intensity (standardized mean difference (SMD) = 2.55; 95% CI = 0.97 to 4.13; P = 0.002), with moderate evidence. Subgroup analysis for pain intensity revealed a significant difference between the sexes, with only the female population (SMD = 6.23, 95% CI = 4.80 to 7.65) showing better outcomes than those with both sexes (SMD = 1.07, 95% CI = 0.57 to 1.56) (p < 0.00001). However, moderate evidence demonstrated no improvement in neck disability after scapular treatment (SMD of 0.24[-0.14, 0.62] of Neck Disability Index or Northwick Park Neck Pain Questionnaire). No effect of scapular treatment was shown on the pressure pain threshold (PPT). The cervical range of motion (CROM) and electromyographic activity of neck muscles could not be conclusively evaluated due to limited support in the articles, and further study was needed. However, the patient's head forward posture appeared to be corrected after scapular treatment.

CONCLUSION

Scapular therapy was beneficial for relieving pain intensity in patients with CNP, especially in women. Head forward posture might also be corrected with scapular therapy. However, scapular therapy may have no effect on the PPT or neck disability. However, whether scapular therapy could improve CROM and cervical muscle activation in patients with CNPs had not been determined and needed further study.

Examination of Myofascial Stiffness and Elasticity in the Upper Trapezius Region in Patients with Unilateral Neck Pain: A Cross-Sectional Study

(1) Background: Globally, neck pain is prevalent, affecting around thirty percent of the population annually. To better understand the influence of pain on the myofascial layers, the present study investigated these on the upper trapezius muscle in unilateral, more severe neck pain. (2) Methods: This study was a cross-sectional study. Forty patients (42.2 ± 14.7) with a confirmed diagnosis of unilateral neck pain were examined using durometry and indentometry. This study evaluated the stiffness, elasticity, and pressure pain threshold of both sides of the neck (symptomatic side: SS; healthy side: HS). Furthermore, the range of motion of the cervical spine (lateral flexion, rotation) was quantified using a digital goniometer. (3) Results: A significant lateral discrepancy was observed in stiffness between groups (durometry: SS-33.76 ± 7.78, HS-29.75 ± 7.45, p < 0.001; indentometry: SS-59.73 ± 33.93, HS-4.18 ± 12.69, p = 0.024). In contrast, no differences were found between the comparison sides of the upper trapezius for the parameter's elasticity (SS-0.101 ± 1.09, HS--0.006 ± 0.29, p = 0.416), cervical spine mobility (lateral flexion: SS-37.08 ± 8.15, HS-37.73 ± 7.61, p = 0.559; rotation: SS-73.55 ± 12.37, HS-72.85 ± 11.10, p = 0.660), and algometry (SS-36.41 ± 17.53, HS-37.22 ± 17.00, p = 0.657). (4) Conclusion: Overall, it can be concluded that more severe neck pain unilaterally shows differences in stiffness on the same side. Future research is needed to investigate the links.

Cervical and axioscapular muscle stiffness measured with shear wave elastography: A comparison between different levels of work-related neck disability

Assessing muscle mechanical properties in terms of stiffness may provide important insights into mechanisms underlying work-related neck pain. This study compared stiffness of cervical and axioscapular muscles between 92 participants (sonographers) with no (n = 31), mild (n = 43) or moderate/severe (n = 18) neck disability. It was hypothesized that participants with more severe neck pain and disability would present with altered distribution of stiffness in cervical and axioscapular muscles than those with no disability. Using shear wave elastography, the shear modulus (kPa) of five cervical and six axioscapular muscles or muscle segments were measured in a relaxed seated upright or side-lying position. Muscle activity was measured simultaneously using surface electromyography during the elastography measurements and scapular depression was measured using a measurement tape and inclinometer before the elastography measurements to evaluate their potential confounding influences on shear modulus. Increased shear modulus was found in deeper than superficial cervical muscles and more cranial than caudal axioscapular muscles. However, no differences in shear modulus of the cervical or axioscapular muscles were found between sonographers with varying levels of disability. This study suggests no alterations in stiffness of cervical and axioscapular muscles were associated with work-related neck pain and disability.

Lower trapezius muscle function in people with and without shoulder and neck pain: a systematic review

CONTEXT

Shoulder and neck pain are leading causes of disability worldwide. Rotator cuff pathology has strong associations with such pain and is extensively targeted by healthcare practitioners. A dysfunctional lower trapezius muscle has also been shown to contribute to neck and shoulder pain, yet it is often overlooked.

OBJECTIVES

This systematic review analyzes those with a history of, or who are currently managing, shoulder or neck pain to indicate differences in measures of lower trapezius function when compared to subjects without that pain.

METHODS

Studies with no age restrictions were included in the study. Studies could determine lower trapezius muscle function with any quantifiable measurement tool or clinical assessment. If the study included a control group (no pain) and a comparator group (pain), and if lower trapezius muscle function was assessed in both, the study was typically included. The significance of the lower trapezius muscle function change was summarized in these pain patients. From a final total of 18 studies identified, level of muscle activity, muscle activation, time to onset, muscle strength, and muscle thickness were reported.

RESULTS

The 18 included articles involved 485 participants with shoulder and/or neck pain and 455 without. Half of the shoulder pain studies (6/12), and all of the neck pain studies (6/6), demonstrated that the lower trapezius had a noticeable impact. The lower trapezius muscle in participants with shoulder and neck pain tended to show decreased muscle strength, and decreased time to onset/latency.

CONCLUSIONS

The findings from this systematic review should be taken into consideration when assessing and treating patients with shoulder and neck pain. Future studies that define the type and duration of shoulder and neck pain, as well as prospectively assessing lower trapezius muscle function in those with and without that pain, are needed.