Relationship Between Strength of Scapular Muscles and Forward Neck Posture in Young Adults

Introduction

Neck pain ranks among the most prevalent musculoskeletal ailments, following closely behind back pain.¹ Many people seek help for this condition at least once in their lifetime. Individuals experiencing chronic neck pain frequently demonstrate changes in posture, particularly when engaged in activities involving extended periods of sitting, such as computer-based tasks, office paperwork, or industrial responsibilities. The continuous presence of neck pain can induce biomechanical shifts in the cervical spine.² Research judgments indicate that about 60% of individuals with neck pain demonstrate forward neck posture (FNP). This altered posture affects various structures including bones, ligaments, joint capsules, and muscles, consequently influencing scapular kinematics and kinetics.³ Research indicates that FNP leads to the shortening of posterior neck extensor muscles, tightening of anterior neck and shoulder muscles, and impacts scapular position and kinematics.⁴ Impairment in the mobility of upper extremity muscles originating from the thorax (such as the Pectoralis major and minor, Latissimus dorsi, and Serratus anterior), as well as muscles of the head and cervical spine linked to the scapula and upper thorax (including Levator scapulae, Sternocleidomastoid, Scalene, and upper Trapezius (UT)), can contribute to forward neck posture. It is well established that the serratus anterior and UT muscles serve as primary stabilizers of the scapula, regulating force to control scapular motion during functional activities.

The increased prevalence of forward neck posture among children and adolescents is closely linked to excessive usage of mobile phones and laptops. Research indicates that FNP alters the biomechanical stress on the cervical spine, contributing to various musculoskeletal disorders including cervical pain, headaches, temporomandibular disorders, and muscular dysfunctions. A smaller cranial-vertebral angle (CVA), indicative of greater FNP, is associated with CVA measurement less than 50 degrees, defining FNP.⁵ Studies have recorded high prevalence rates of forward neck posture (FNP) across different demographics. For instance, in one study, researchers reported an FNP prevalence of 86.5%, with a notable association between gender and FNP.⁶ Additionally, among heroin users, 36.7% exhibited moderate FNP, while 20% had severe FNP.⁷ In children and teenagers, the prevalence of FNP was reported at 53.5%, showing some correlation with neck pain.⁸ University students exhibited a prevalence of approximately 63.96% for FNP, while among the physiotherapy population, the prevalence was recorded at 70%.^9,10 Furthermore, studies have observed a 66% prevalence of FNP among individuals aged 25-30, with a higher prevalence noted in women compared to men.¹¹ These findings underscore the significant impact of FNP across various age groups and populations, emphasizing the importance of proactive measures to address and manage this condition.

A recent study highlighted that nearly 78% of individuals habitually maintain their neck in a working position for extended periods, resulting in persistent stress on the neck and shoulders, potentially leading to anterior neck positioning, or FNP.¹² This prolonged stress can contribute to tightness in the upper back and muscle spasms, ultimately resulting in sharp pain. In a recent article published in 2022, it was suggested that incorporating scapular stabilization exercises may offer a more effective approach to managing FNP.¹³ Both scapular stabilization and postural correction exercises have been demonstrated to enhance the CVA and pressure pain threshold (PPT), while simultaneously reducing muscle activity and disability. Research indicates that performing scapular stabilization exercises alone has been demonstrated to enhance CVA. Diversified research studies have designated that forward neck posture correlates with the shortening of posterior neck extensor muscles, tightening of anterior neck and shoulder muscles, and changes in scapular position and kinematics. The serratus anterior and upper trapezius (UT) muscles play key roles as primary stabilizers of the scapula, essential for controlling the force required to manage scapular motion during daily activities. Coordinated movements of the serratus anterior and UT muscles are crucial for ensuring proper scapular movements, including the correct recruitment and initiation of these muscles.

The significance of scapular muscle strength lies in its direct impact on biomechanics, particularly concerning the shoulder complex and upper limb function. Shoulder Stability Scapular muscles, such as the trapezius, serratus anterior, and rhomboids, are crucial for stabilizing the shoulder joint. They help maintain the optimal positioning of the scapula on the rib cage during various arm movements. Weakness or imbalance in these muscles can lead to altered shoulder biomechanics, affecting stability during activities such as lifting, pushing, and pulling.

Shoulder Movement Patterns - Strong scapular muscles support proper movement patterns of the shoulder joint. Adequate strength in these muscles promote smooth and coordinated movement, reducing the risk of overuse injuries or biomechanical dysfunction.

Injury Prevention - Optimal scapular muscle strength is essential for preventing injuries such as shoulder impingement syndrome and rotator cuff tears. When these muscles are weak, there is increased stress on other structures of the shoulder complex, including the tendons and ligaments, which can lead to overuse injuries or abnormal wear and tear over time.

Postural Alignment - Scapular muscle strength contributes significantly to maintaining proper posture, particularly in the upper back and shoulder regions. Weak scapular muscles can contribute to rounded shoulders and forward head posture, which can lead to musculoskeletal pain and dysfunction.

In conclusion, there is a direct relationship between the biomechanical alterations in shoulder function and the significance of scapular muscle strength. Strengthening these muscles is crucial for maintaining shoulder stability, promoting proper movement patterns, preventing injuries, and enhancing overall upper limb function and performance

The increasing prevalence of forward neck posture (FNP) is partly attributed to the growing use of mobile phones among young individuals. Research suggests that FNP not only induces discomfort but also impacts breathing patterns, sleep quality, and may contribute to numbness in limbs. This underscores the significance of evaluating FNP prevalence to mitigate potential complications. Early identification and correction of posture should be prioritized to mitigate the onset or progression of FNP. Ongoing research is exploring the effectiveness of scapular stabilization techniques in managing neck pain and enhancing posture in affected populations. While FNP has been noted in young students, its association with scapular muscle strength remains unclear. Therefore, this study seeks to examine the relationship between scapular muscle strength and FNP in young adults.

Forward neck posture, often associated with a slouched or rounded upper back, can lead to musculoskeletal discomfort and reduced mobility over time. Effective therapy aims to address muscular imbalances, improve posture, and alleviate associated symptoms. Here are evidence-based approaches commonly used.

Postural Correction Exercises - Specific exercises targeting the muscles of the neck, upper back, and shoulders can help strengthen weak muscles and stretch tight ones. For instance, exercises that focus on retracting the scapulae (shoulder blades), such as scapular squeezes and rows, can improve upper back posture and reduce forward head positioning.

Cervical Retraction Exercises - These exercises aim to strengthen the deep neck flexors and encourage cervical spine alignment. One effective exercise is cervical retraction, where you gently retract your head backward without tilting it up or down. This helps counteract the forward head posture and encourages a more neutral alignment.

Stretching and Range of Motion Exercises - Tight muscles in the chest (pectoralis major and minor) and anterior neck (scalenes) often contribute to forward neck posture. Stretching these muscles can help restore flexibility and reduce the pull that contributes to poor posture. Examples include doorway stretches for the chest and neck stretches targeting the sternocleidomastoid and scalene muscles.

Ergonomic Modification - Correcting work or study environments to promote better posture can significantly support therapy outcomes. This may involve adjusting chair height, computer screen position, or using ergonomic aids like lumbar supports or standing desks to encourage better posture throughout the day.

Manual Therapy Techniques such as soft tissue mobilization, myofascial release, and joint mobilization performed by physical therapists or chiropractors can help alleviate muscle tightness and joint restrictions contributing to forward neck posture.

Education and Behavioural Modification - Teaching individuals about the importance of posture and providing strategies to integrate good posture habits into daily activities can reinforce therapy outcomes. This includes awareness of body positioning during activities like sitting, standing, and using digital devices. Evidence supporting these approaches comes from studies evaluating the effects of exercise programs, ergonomic interventions, and manual therapies on posture-related conditions. These interventions not only improve posture but also reduce neck pain, enhance functional ability, and prevent the progression of postural deviations. For best results, therapy should be tailored to individual needs and monitored for ongoing improvement.

Materials and Methods

A sample size of 54 was obtained using G Power software (version 3.1.9.2) with input parameters of effect size 0.3, alpha error of 0.10, and power of 0.90. The correlation Ph0 was 0.

Permission from the Institutional Research Committee (IRC) was obtained prior to commencing the study. Participants aged 18-25 years from the same community and social status and those who had forward neck posture were recruited for the study. The exclusion criteria encompassed individuals experiencing neck pain and participants with restricted shoulder range of motion (ROM). Participants were enrolled in the study following the acquisition of written informed consent.

Standardization of procedure

An initial pilot case study was conducted involving six subjects to establish a standardized research protocol. Through interpretation and analysis, modifications to the measurement procedure were implemented. It was observed that using a Goniometer to measure the CVA posed challenges, while employing Image J software proved to be more feasible. Studies have corroborated that utilizing Image J software for measuring the CVA yields greater reliability.

Recruitment of participants

All the undergraduate and postgraduate students of JSS College of Physiotherapy were contacted (n=210). Twenty-six subjects had shoulder pain and 69 of them did not consent. A total of 115 participants were recruited. After screening, 54 had forward neck posture, and 61 had normal neck posture. The aim, procedure, and instructions were explained to the participants, and consent was obtained from them. Initially, demographic data was recorded.

Procedure

Participants underwent a five-minute warm-up session that included stretching of the upper limbs, chin-to-chest stretch, shoulder rolls, neck rolls, and side stretching, followed by a 5-minute cool-down period. This involved a shoulder stretch, triceps stretch, forward bend, overhead stretch, and chest stretch.

Muscle strength assessment

Strength was assessed in three consecutive trials and after one muscle strength test, participants were given a 10-minute break. Afterward, the identical procedure was replicated for the assessment of other muscles. The strengths of both left and right rhomboids, UT, middle trapezius (MT), and lower trapezius (LT) muscles were measured using standardized measurement methods. Strength was assessed using a hand-held dynamo meter (HHD) (MicroFET2 make, model Hogan Health Technologies Inc., Salt Lake City, UT, USA) for bilateral (B/L) rhomboids, UT, MT, and LT

Procedure for assessment and recording of rhomboids, UT, MT, and LT

Participants’ positioning during the strength assessment was standardized to ensure consistency. For evaluating upper trapezius strength, participants were seated in an armless chair with hands resting on thighs, while the therapist stood behind them. A dynamometer was positioned 2 cm from the shoulder joint to measure strength. To assess middle trapezius strength, participants lay prone at a table’s edge, with the shoulder abducted to 90 degrees and the elbow flexed at a right angle. The therapist stood on the test side, near the participant’s arm, providing downward resistance. For evaluating lower trapezius strength, participants assumed a prone position at the table’s edge, with the shoulder abducted to 145 degrees and the elbow flexed at a right angle. The therapist stood on the test side, near the participant’s arm, stabilizing the contralateral scapular area to prevent trunk rotation, and providing downward resistance. During the assessment, participants were instructed to raise their arms from the table to ear level and resist the downward force applied just 2 cm below the acromion process. Strength measurements were conducted three times consecutively, with a 10-minute interval provided after each assessment to minimize fatigue. The average of the three measurements was appropriated for analysis to enhance accuracy and reliability.

Procedure for measuring CVA

Markers were placed on the tragus of the ear and the C7 spinal process. Participants were then directed to stand 40 cm away from a backdrop, perform three forward bends, three overhead reaches, and then resume a straight-ahead standing position. A mobile camera with a resolution of 48 MP was employed to capture lateral view photos of the subjects. Computational image processing software, specifically Image J software, was utilized to measure the cervical vertebral angle (CVA) by determining the angles between the centers of the markers. Additionally, the forward head angle (FHA) was measured from the anterior vertical to a line connecting the tragus and the C7 marker. CVA measurements were performed thrice, and the resultant average value was appropriated for subsequent analyses.

In the analysis done, 54 of the subjects had FNP with CVA less than 50 degrees.

Data analysis was done using measurements of CVA, and the strength of scapular muscles was plotted in an Excel worksheet for the participants with FNP. The Excel worksheet was copied to SPSS 22 software for analysis and to find the correlation between the FNP and scapular muscle strength.

Materials required

MicroFET HHD, mobile phone, Image J software, SPSS software, and G Power software

Results

The data underwent analysis using SPSS 22 software, with statistical significance defined as P <0.05. Analysis involved correlating scapular muscle strength with forward neck posture using the Pearson correlation coefficient. Results indicated no significant relationship between forward neck posture (FNP) and scapular muscle strength.

The average age of participants was 20.78 years with a standard deviation of 1.01. Their average height was 165.0 cm with a standard deviation of 7.88, and their average weight was 60.90 kg with a standard deviation of 9.15.

Discussion

The main aim concerning this study was to understand the potential correlation between scapular muscle strength and forward neck posture (FNP) among college students. A total of 54 participants meeting the inclusion criteria were included in the study, encompassing both genders, with males comprising 52% and females 48%, aged between 18 and 25 years. Forward neck posture (FNP) was evaluated using the cervicothoracic vertebral angle (CVA), while the scapular muscle strength was evaluated utilizing the MicroFET handheld dynamo-meter (HHD). The findings from the study indicate that there is no statistically important correlation between scapular muscle strength and forward neck posture (FNP) in young adults. Previous research by Sally Wagner et al. highlighted alterations in Trapezius muscle behaviour in individuals experiencing mechanical neck pain and exhibiting poor scapular posture during typing tasks.¹³ The comparison was made with a control group characterized by ‘good’ scapular posture. Similarly, Szeto et al. observed individuals employed in office settings experiencing neck pain displaying erratic scapular protraction behaviour, linked to altered behaviour in the Upper Trapezius (UT) muscle and correlated with neck pain severity.¹⁴ Thigpen et al.reported reduced activity in the serratus anterior muscle among patients with forward neck posture (FNP) during overhead shoulder flexion tasks.¹⁵ This suggests its involvement in the biomechanical alterations of the scapula associated with poor posture, such as increased thoracic kyphosis and anterior shoulder positioning, commonly observed in individuals with neck disorders. The prevalence of specific scapular positions is not well-defined, but a recent study on individuals with nonspecific neck pain found that approximately 60% had down-wardly rotated scapulae, and all participants exhibited at least one type of scapular positioning impairment.¹⁶ However, this study focused on young adults without neck pain or musculoskeletal issues, thus limiting the generalization of findings to this population. Participants in this study, despite presenting with forward neck posture (FNP) did not report concurrent neck pain or muscle spasms, likely due to their age and presumed adequate scapular muscle strength. However, it is important to acknowledge the limitations of this study, including the absence of severe forward head posture classification and the relatively small sample size.

In summary, this study found no significant correlation between scapular muscle strength and forward neck posture (FNP) in young adults without musculoskeletal issues, suggesting the absence of scapular muscle weakness and neck pain in this population.

Conclusion

From this study, it can be concluded that there is no relationship between scapular muscle strength and the FNP in young adults.

Ethics Approval

The project titled “Relationship Between Strength of Scapular Muscles and Forward Neck Posture in Young Adults” has received clearance and approval from the institutional research committee of JSS College of Physiotherapy.

Conflict of interest

Nil