Leila Rahnama

Differences in Cervical Multifidus Muscle Thickness During Isometric Contraction of Shoulder Muscles: A Comparison Between Patients With Chronic Neck Pain and Healthy Controls

OBJECTIVE The purposes of this study were to (1) measure the thickness of cervical multifidus muscle (CMM) in different maximal voluntary contraction percentages of isometric contraction of shoulder muscles, (2) evaluate the differences of the CMM thickness in different directions of the shoulder movement, and (3) compare the changes in the CMM thickness of participants with neck pain and also of healthy individuals. METHODS Twenty healthy men (age, 27.45 ± 4.37 years; height, 177 ± 4.66 cm; weight, 72.85 ± 6.46 kg) and 20 men with chronic mechanical neck pain (age, 28.90 ± 5.53 years; height, 176 ± 5.98 cm; weight, 73.15 ± 7.82 kg) participated in the study. Both the right and left CMM thicknesses were measured using an ultrasound device while participants performed isometric contraction of shoulder muscles in 6 movement directions. RESULTS In both groups, an increment of CMM thickness followed as the increase of isometric force (P < .01).The increase of muscle thickness of healthy participants was substantially more than the chronic mechanical neck pain participants (P = .03). Although no significant difference of CMM thickness was seen among the effects of the 6 force directions (P > .05), there was a significant difference of activity noted between the left and right sides (P = .047). CONCLUSION The results of the present study indicate that isometric contraction of shoulder muscles caused an increase in the CMM thickness regardless of force direction. This increase was seen in both groups of healthy participants and patients with neck pain. However, less thickness changes were observed in participants with neck pain, which may be interpreted as reduced CMM activity in such people.

The effects of isometric contraction of shoulder muscles on cervical multifidus muscle dimensions in healthy office workers.

It is argued that cervical multifidus muscles (CMM) are responsible for providing neck stability. However, whether they are actually activated during the tasks performed by the upper extremities to the neck is still unknown. Therefore, the aim of this study was to examine the effects of isometric contraction of shoulder muscles on the dimensions of CMM. Twenty three healthy males voluntarily participated in this study. Ultrasonography imaging of CMM was conducted at rest and at 25%, 50%, 75%, and 100% of maximal voluntary contraction of shoulder muscles in 6 directions of shoulder movements. Anterior-posterior dimension (APD), lateral dimension (LD), shape ratio and multiplied linear dimension (MLD) of cervical multifidus were measured. The APD of CMM was increased while LD and shape ratio were decreased by shoulder muscles contraction (P < 0.01).

Reliability of new software in measuring cervical multifidus diameters and shoulder muscle strength in a synchronized way; an ultrasonographic study

OBJECTIVES: This study was conducted with the purpose of evaluating the inter-session reliability of new software to measure the diameters of the cervical multifidus muscle (CMM), both at rest and during isometric contractions of the shoulder abductors in subjects with neck pain and in healthy individuals. METHOD: In the present study, the reliability of measuring the diameters of the CMM with the Sonosynch software was evaluated by using 24 participants, including 12 subjects with chronic neck pain and 12 healthy individuals. The anterior-posterior diameter (APD) and the lateral diameter (LD) of the CMM were measured in a resting state and then repeated during isometric contraction of the shoulder abductors. Measurements were taken on separate occasions 3 to 7 days apart in order to determine inter-session reliability. Intraclass correlation coefficient (ICC), standard error of measurement (SEM), and smallest detectable difference (SDD) were used to evaluate the relative and absolute reliability, respectively. RESULTS: The Sonosynch software has shown to be highly reliable in measuring the diameters of the CMM both in healthy subjects and in those with neck pain. The ICCs 95% CI for APD ranged from 0.84 to 0.94 in subjects with neck pain and from 0.86 to 0.94 in healthy subjects. For LD, the ICC 95% CI ranged from 0.64 to 0.95 in subjects with neck pain and from 0.82 to 0.92 in healthy subjects. CONCLUSIONS: Ultrasonographic measurement of the diameters of the CMM using Sonosynch has proved to be reliable especially for APD in healthy subjects as well as subjects with neck pain.

Ultrasonographic assessment of cross-sectional area of deep neck flexor muscles during a five-stage cranio-cervical flexion test in individuals with chronic neck pain and healthy controls

Abstract Aims: The objective of this study was to investigate and compare the cross-sectional area (CSA) of deep neck flexor muscles (DNFs) in individuals with chronic non-specific neck pain (CNNP) and healthy controls while performing a five-stage cranio-cervical flexion (CCF) test. Methods: Twenty individuals with CNNP and 20 healthy controls voluntarily participated in this case–control study. Cross-sectional area of DNFs was measured using ultrasonography while the participants lay in supine position to perform the CCF test. The five stages of the CCF test were determined by a pressure biofeedback tool. Neck disability index and pain were also assessed. Repeated measures analysis of variance was used to interpret the yielded data. Results: A significant difference was observed in the CSA of DNFs between individuals with CNNP and healthy controls at the pressure of 24 mm (p = .009) of the CCF test. The CSA of DNFs significantly changed through increasing the CCF test pressure. No significant differences were observed on the right and left-side DNFs, neither in healthy controls, nor in individuals with CNNP. Conclusions: The CSA changes in individuals with CNNP and healthy controls significantly varied during the CCF test, which may be a reasonable explanation to the muscle weakness and atrophy in individuals sustaining CNNP.

Scapular Upward Rotator Morphologic Characteristics in Individuals With and Without Forward Head Posture: A Case-Control Study: Scapular Upward Rotators in Forward Head Posture

There are several reports suggesting that forward head posture contributes to alterations in scapular kinematics and muscle activity, leading to the development of shoulder problems. Currently, it is unknown whether forward head posture alters the thickness of the scapular muscles. The aim of this study was to compare the thickness of the serratus anterior and upper and lower trapezius muscles at rest and during loaded isometric contractions in individuals with and without forward head posture.

Differential Activation of the Dorsal Neck Muscles During a Light Arm-Elevation Task in Patients With Chronic Nonspecific Neck Pain and Asymptomatic Controls: An Ultrasonographic Study

Disturbance in neck muscle function is a well‐known complication of chronic nonspecific neck pain (CNNP). It is, however, unclear which muscles are more susceptible to functional impairment in patients with CNNP during upper limb tasks.

The Effects of Forward Head Posture on Neck Extensor Muscle Thickness: An Ultrasonographic Study

Objective: This study aimed to compare neck extensor muscle thickness, thickness changes, and strength between participants with forward head posture (FHP) and controls with normal head posture (NHP). Methods: Twenty college students with FHP (mean age 21.30 ± 2.36 years) and 20 students with NHP (mean age 21.85 ± 2.78 years) participated in this case‐control study. The thickness of neck extensor muscles was measured at rest and at maximal voluntary isometric contraction (MVIC). In addition, the craniovertebral angle (CVA) was calculated. To compare thickness changes between the 2 groups and among 5 muscles, a 2‐way repeated measures analysis of variance was applied. In addition, Pearsons correlation test was performed to investigate the relationship between neck extensor MVIC and CVA. Results: The FHP group demonstrated lower MVIC compared with the NHP group (P = .03). Semispinalis capitis showed the smallest thickness changes during neck extensor MVIC in FHP compared with the controls (P < .001). However, no significant difference in terms of muscle thickness was observed between the 2 groups at the state of rest (P = .16‐.99). A positive association was also found between the MVIC and CVA (P = .02). Conclusions: Semispinalis capitis had less thickness changes during MVIC of neck extensors in individuals with FHP compared with those with NHP. This indirectly implies lower activity of this muscle in FHP condition. This study finding may help researchers develop therapeutic exercise protocols to manage FHP.