The effect of smartphone texting on cervical spine sagittal alignment in healthy young adults

Abstract

Background

Never before has technology been so universally accepted as the modern-era cell phone, the smartphone. Spine surgeons have noticed a rise in patients in their offices complaining of neck and upper back pain. Many patients are of the younger age group, and one thing they all seem to have in common is prolonged smartphone use. While using a smartphone, the cervical spine demonstrates flexion angles ranging from 15 to 60 degrees, with more pronounced deviations from the neutral position observed during sitting compared to standing, and while texting compared to web browsing or video watching. Nowadays, there is strong evidence that persistent neck pain and radiculopathy are associated with time spent text messaging. While it now seems rather clear that repetitive texting, or similar activity while utilizing a forward flexed neck position, may lead to neck pain or “text neck”, what is currently unknown is whether this poses a risk for intervertebral disk degeneration and consequent cervical spondylosis, and if so, at what age the condition will emerge and which levels of the cervical spine will it affect the most. The aim of this study was to evaluate the effects of smartphone texting on cervical spine sagittal alignment in healthy young adults, and to identify which cervical segments are most affected, particularly comparing sitting versus standing postures.

Methods

We took lateral radiographs of the cervical spine of healthy volunteers younger than 40 years old. The radiographs were made while texting on a smartphone and in a neutral position, sitting and standing. Then we measured the disc angles, vertebral angles, and sagittal angles on each radiograph.

Results

When texting while standing, significant (P≤0.05) changes in the intervertebral angles (IVAs) were seen at foramen magnum (FM)–C2, FM–C3, FM–C4, C1–2, C2–4, C2–T1, C3–4, C3–5, C3–6, C3–7 and C3–T1. The significant changes in the interdiscal angles (IDAs) were seen at C3–4, C4–5. No significant changes were seen in the angle of lordosis (AOL). When texting while sitting, the significant (P≤0.05) changes in the IVAs were at IVAs: FM–C2, FM–C3, FM–C4, C1–2, C1–3, C1–4, C2–7, C2–T1, C3–4, C3–5, C3–6 and C5–7. The significant changes in the IDAs were at C3–4, C5–6. No significant changes were seen in the AOL.

Conclusions

Our observation shows that the most significant changes in the cervical spine while texting occur in the upper segments of the cervical spine, more pronounced while sitting.

Highlight box.

Key findings

• Smartphone texting significantly alters cervical spine sagittal alignment, especially in the upper cervical segments [foramen magnum (FM)/C2, C1/C2, C3/C4].

• Postural changes were more pronounced while sitting than standing.

• Despite these changes, no significant alterations were observed in overall cervical lordosis.

What is known and what is new?

• It is known that smartphone use in flexed-neck positions is associated with neck pain and altered spinal biomechanics.

• This study adds radiographic evidence of specific segmental changes in healthy young adults during texting, highlighting vulnerability in upper cervical levels. It is the first study to systematically compare sitting vs. standing postures during active texting using objective imaging and angle measurements. This study demonstrates, with radiographic evidence, that smartphone texting significantly alters cervical sagittal alignment, particularly in the upper cervical segments

What is the implication, and what should change now?

• Frequent texting in a seated, forward-flexed position may predispose young adults to early cervical spine degeneration.

• Public health efforts should emphasize ergonomic awareness, limit prolonged neck flexion, and encourage proper posture during device use.

• Clinicians should consider smartphone-related postural habits when evaluating young patients with neck discomfort.

Introduction

The modern era cell phone, otherwise known as the smartphone, is one of the most universally accepted technologies today. The social implication of this epidemic is altogether another topic, but of concern to the modern era physician is the potential musculoskeletal consequences of this behavior.

Spine surgeons have observed an increasing number of patients reporting neck and upper back pain, particularly among younger individuals. Among these patients, some present with disk herniations, others with kyphotic spine alignment, and some with normal imaging studies. A common factor identified across these cases is prolonged smartphone use. Cuéllar et al. have termed this condition “text neck” (1).

During smartphone use, the cervical spine typically adopts a flexion angle ranging from 15° to 60°, with the most common angles between 33° to 45°. Greater flexion angles are observed when sitting as opposed to standing, and when texting compared to web browsing or watching videos (2). The inclination of the neck during smartphone use may be due to reduced muscle fatigue; a study utilizing electromyography found that less immediate muscle fatigue and pain in the upper trapezius muscles occurred at 50° of flexion compared to 0° or 30°. However, from a biomechanical perspective, as the head tilts forward, the forces exerted on the neck increase significantly (3)—rising to 27 pounds at 15°, 40 pounds at 30°, 49 pounds at 45°, and 60 pounds at 60° (4). Generally, compression forces escalate from the cranial to caudal regions of the cervical spine. In a neutral posture, there is a consistent 18 N of anterior shear at each joint level. With increased flexion, compression doubles throughout the cervical spine, while anterior shear quadruples in the upper cervical spine and decreases markedly caudally (5). Gait analysis studies have shown significantly greater thoracic kyphosis and lumbar lordosis during texting (6), underscoring the impact of smartphone use on spinal alignment. Moreover, prior ergonomic studies have identified differences in texting techniques between symptomatic and asymptomatic individuals. Asymptomatic subjects more frequently exhibited sitting postures with back and forearm support and maintained a neutral head position. Additionally, variations in muscle activity and kinematics were noted between the different texting techniques (7).

In a large, longitudinal, population-based cohort study conducted in Sweden, involving over 7,000 young adult subjects (ages 20–24 years) over a 5-year period, Gustafsson et al. provided compelling evidence that persistent neck and upper back pain is associated with the duration of time spent text messaging (8). Additionally, an association was also found between reported shoulder pain, as well as numbness and tingling in the hands or fingers, among those who spent the most time texting (9). Derakhshanrad et al. demonstrated that excessive smartphone users have a sixfold higher risk of developing neck pain (10). A study of 107 young adults (ages 20–35 years) with neck pain revealed a significant correlation between smartphone usage duration and both sagittal balance (cervical lordosis) and degeneration parameters, including Modic changes and disc displacement (11). In a study of 2,438 participants, Zhuang et al. employed the “Smartphone Addiction Scale” questionnaire to identify excessive smartphone users and found that these users exhibited significantly higher “Cervical Disc Degeneration Scores” (12).

Cervical spondylosis is a well-established condition resulting from long-term degeneration. Radiographic evidence of spondylotic changes is observed in 50% of adults over the age of 40 years and in 85% of adults over the age of 60 years, but in no more than 25% of individuals under 40 years. The most affected sites for degeneration and spondylotic changes are at the C5–6 level, followed by C6–7 and C4–5 (13). It appears increasingly evident that repetitive activities, such as texting, which involve maintaining a forward-flexed neck position, may contribute to neck pain, commonly referred to as “text neck”, and associated degenerative changes (14-17). This raises questions about which specific segments or levels of the cervical spine are most likely to be affected by these changes and whether they may manifest at a younger age.

This study aims to investigate changes in cervical sagittal alignment and identify the specific levels affected during smartphone texting. Given that 50% of cervical flexion occurs at the C1–2 level and 30% at the C3–5 level (18), we predict that significant changes will be observed in the upper segments of the cervical spine, and, consistent with previous literature, to a greater extent while texting in a seated position. We present this article in accordance with the STROBE reporting checklist (available at https://jss.amegroups.com/article/view/10.21037/jss-24-19/rc).

Methods

We designed a cross-sectional observational study that compares cervical spine alignment while standing and sitting, both in neutral position and while using a smartphone, in healthy young adults.

This study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by ethics committee of Rambam Health Care Campus (No. 0410-20), and informed consent was taken from all the patients. After obtaining the necessary permits and Helsinki Committee approval, an advertisement was posted on the hospital’s website to recruit volunteers. The volunteers were provided with information regarding radiation exposure, including the nature of the exposure in this study and their expected participation, and were instructed to act naturally. They were not informed about the specific tests or measurements conducted. Verbal and written consent were obtained from all participating volunteers. All participants had the possibility to withdraw from the study at any point, although no one withdrew.

Eligibility criteria included individuals aged 18 to 40 years (to exclude those more likely to exhibit spondylotic changes, which become more prevalent after age 40 years), who were healthy, without neck pain or a history of neck problems, and not pregnant. Each volunteer underwent four lateral cervical X-ray images: standard lateral X-ray images while standing and seated, and images while performing a texting task, both standing and sitting. Each texting task lasted between 10 to 15 minutes on a common smartphone (Xiaomi Redmi 9, M2004J19G). The task consisted of a medium-level unseen text followed by 10 questions. Volunteers were instructed to respond to the questions by texting immediately upon knowing the answer, and X-ray images were captured after the ninth response was sent. This setup was designed to simulate typical daily texting:

• ❖ A text requiring concentration for a sufficiently long duration, allowing volunteers to flex their necks to their usual and comfortable position.

• ❖ Immediate responses to simulate a real-time texting conversation.

• ❖ Images were taken after the ninth response to capture the volunteers in a position as close as possible to their habitual flexed posture, without having yet finished the task and regained a neutral position (Figure 1).

Figure 1.

Lateral cervical X-ray while texting and sitting.

Sagittal intervertebral angles (IVAs)—the angle between the upper surface of the superior vertebra and the lower surface of the inferior vertebra, from the base of the skull, at the level of the foramen magnum (FM), to the upper surface of the T1 vertebral body—were measured. Sagittal interdiscal angles (IDAs)—the angle between the lower surface of the superior vertebra and the upper surface of the inferior vertebra from C2–3 to C7–T1—and the angle of lordosis (AOL)—the angle between the posterior surfaces of C2 and C7—were also assessed. To minimize the number of measurements and measurement errors, angles were first measured from each vertebra’s upper and lower surfaces to a horizontal line (parallel to the floor), and then the differences between these primary angles were calculated (Figure 2). For example, the C3/C4 IVA was derived from the difference between the upper surface of C3 and the horizon, minus the lower surface of C4 and the horizon.

Figure 2.

Angles measurements on lateral cervical X-ray (While texting and standing).

Statistical analysis

Changes in the angles between the standard standing and standing-with-texting images, as well as between the standard sitting and sitting-with-texting images, were analyzed. All angles were measured twice by two experienced physicians specializing in cervical X-ray analysis, with an intraclass correlation coefficient (ICC) of 0.95.

Sample size analysis conducted using the G*Power program with a type I error rate of alpha of 0.05, a power of 85%, and an effect size of 0.3 yielded a total sample of 34 subjects. Data were analyzed using descriptive statistics, including means and standard deviations of paired angle measurements. In this study, quantitative variables were analyzed as continuous variables. Descriptive statistics (mean ± standard deviation) were used to summarize the data. For statistical analysis, variables were included as continuous predictors as well. Diagrams illustrating the angle measurements during sitting and standing were created. Paired-sample t-test was employed to assess statistical differences between the means of the angles in sitting/standing versus non-sitting/standing conditions. Bonferroni correction was applied to adjust P values to account for the increased risk of type I error due to multiple statistical comparisons. All statistical analyses were conducted using IBM SPSS software version 23 (IBM Corporation, Armonk, New York, United States).

Results

A total of 34 healthy volunteers, comprising 11 females and 23 males aged 20 to 39 years, with no neck pain or history of cervical pathology, participated in the study. For each volunteer, 172 angles were calculated: 36 IVAs while standing and texting, 36 IVAs while sitting and texting, 36 IVAs while standing without texting, 36 IVAs while sitting without texting, 6 IDAs while standing and texting, 6 IDAs while sitting and texting, 6 IDAs while standing without texting, 6 IDAs while sitting without texting, and 4 AOL measurements—one each for standing and sitting with and without texting (Figures 3,4).

Figure 3.

Mean measured angles while standing. AOL, angle of lordosis; FM, foramen magnum; IDA, interdiscal angle.

Figure 4.

Mean measured angles while sitting. AOL, angle of lordosis; FM, foramen magnum; IDA, interdiscal angle.

While texting in a standing position, significant changes (P≤0.05) were observed in the following IVAs: FM–C2, FM–C3, FM–C4, C1–2, C2–4, C2–T1, C3–4, C3–5, C3–6, C3–7, and C3–T1. Significant changes in IDAs were noted at: C3-C4 and C4-C5. No significant changes were detected in the AOL (Table 1).

Table 1. Changes in measured angles while texting and standing vs. no texting and neutral standing.

Pair	Mean	Standard deviation	95% confidence interval		t value	P value
			Lower	Upper
FM–C1	1.81	9.62	−1.55	5.17	1.10	0.28
FM–C2	−10.28	15.86	−15.81	−4.74	−3.78	<0.001
FM–C3	−9.13	18.04	−15.42	−2.83	−2.95	0.01*
FM–C4	−6.48	18.64	−12.99	0.02	−2.03	0.05
FM–C5	−1.33	15.49	−6.73	4.08	−0.50	0.62
FM–C6	1.60	14.39	−3.42	6.62	0.65	0.52
FM–C7	2.42	16.94	−3.49	8.33	0.83	0.41
FM–T1	4.42	19.22	−2.29	11.13	1.34	0.19
C1–2	−7.86	16.88	−13.75	−1.97	−2.71	0.01*
C1–3	−5.48	17.82	−11.70	0.74	−1.79	0.08
C1–4	−2.21	19.33	−8.96	4.53	−0.67	0.51
C1–5	3.25	16.25	−2.42	8.92	1.17	0.25
C1–6	5.29	15.64	−0.17	10.75	1.97	0.06
C1–7	4.63	19.85	−2.30	11.56	1.36	0.18
C1–T1	5.45	22.92	−2.55	13.45	1.39	0.18
C2–3	0.85	7.69	−1.83	3.54	0.65	0.52
C2–4	3.55	7.95	0.78	6.32	2.60	0.01*
C2–5	3.53	11.33	−0.42	7.48	1.82	0.08
C2–6	3.75	15.05	−1.50	9.00	1.45	0.16
C2–7	5.41	16.55	−0.37	11.18	1.90	0.07
C2–T1	10.18	17.52	4.06	16.29	3.39	<0.001
C3–4	−3.00	4.58	−4.60	−1.40	−3.82	<0.001
C3–5	−7.34	5.97	−9.42	−5.25	−7.17	<0.001
C3–6	−7.49	8.43	−10.43	−4.55	−5.18	<0.001
C3–7	−6.85	12.67	−11.27	−2.43	−3.15	<0.001
C3–T1	8.91	18.38	2.49	15.32	2.83	0.01*
C4–5	−2.16	4.18	−3.62	−0.71	−3.02	<0.001
C4–6	−2.49	7.32	−5.05	0.06	−1.99	0.06
C4–7	−3.47	11.42	−7.46	0.51	−1.77	0.09
C4–T1	0.77	13.43	−3.92	5.45	0.33	0.74
C5–6	−1.68	5.16	−3.48	0.12	−1.90	0.07
C5–7	−1.85	8.62	−4.86	1.16	−1.25	0.22
C5–T1	2.55	8.21	−0.32	5.42	1.81	0.08
IDA C2–3	0.29	5.75	−1.72	2.29	0.29	0.77
IDA C3–4	3.63	5.85	1.59	5.67	3.62	<0.001
IDA C4–5	2.19	4.53	0.61	3.78	2.82	0.01*
IDA C5–6	0.41	4.44	−1.14	1.96	0.54	0.59
IDA C6–7	0.03	4.21	−1.43	1.50	0.04	0.96
IDA C7–T1	0.15	4.25	−1.33	1.64	0.21	0.84
AOL	0.09	3.90	−1.27	1.45	0.13	0.90

Significant changes (P≤0.05) are seen in IVAs: FM–C2, FM–C3, FM–C4, C1–2, C2–4, C2–T1, C3–4, C3–5, C3–6, C3–7, C3–T1, C4–5. And in IDAs: C3–4, C4–5. *, P values with significant difference between the two values (less than 0.05). AOL, angle of lordosis; FM, foramen magnum; IDA, interdiscal angle; IVA, intervertebral angle.

While texting in a sitting position, significant changes (P≤0.05) were observed in the following IVAs: IVAs: FM–C2, FM–C3, FM–C4, C1–2, C1–3, C1–4, C2–7, C2–T1, C3–4, C3–5, C3–6, and C5–7. Significant changes in IDAs were noted at: C3–4 and C5–6. No significant changes were detected in the AOL (Table 2).

Table 2. Changes in measured angles while texting and sitting vs. no texting and neutral sitting.

Pair	Mean	Standard deviation	95% confidence interval		t value	P value
			Lower	Upper
FM–C1	−0.68	5.85	−2.72	1.36	−0.68	0.50
FM–C2	−10.96	16.70	−16.78	−5.13	−3.82	<0.001
FM–C3	−10.66	17.74	−16.85	−4.48	−3.51	<0.001
FM–C4	−7.46	17.91	−13.70	−1.21	−2.43	0.02*
FM–C5	−2.56	16.22	−8.22	3.10	−0.92	0.36
FM–C6	−3.78	16.53	−9.55	1.98	−1.33	0.19
FM–C7	−0.69	17.98	−6.96	5.58	−0.22	0.82
FM–T1	1.25	19.34	−5.50	8.00	0.38	0.71
C1–2	−7.04	14.46	−12.09	−2.00	−2.84	0.01*
C1–3	−7.88	14.66	−12.99	−2.77	−3.14	<0.001
C1–4	−5.82	16.16	−11.46	−0.18	−2.10	0.04*
C1–5	−0.44	16.09	−6.06	5.17	−0.16	0.87
C1–6	−1.69	19.24	−8.40	5.02	−0.51	0.61
C1–7	−1.67	19.00	−8.30	4.96	−0.51	0.61
C1–T1	0.71	20.94	−6.60	8.02	0.20	0.84
C2–3	−1.81	8.36	−4.73	1.11	−1.26	0.22
C2–4	2.05	8.36	−0.87	4.96	1.43	0.16
C2–5	2.63	10.21	−0.93	6.19	1.50	0.14
C2–6	2.74	13.35	−1.92	7.40	1.20	0.24
C2–7	6.81	13.73	2.02	11.61	2.89	0.01*
C2–T1	11.59	13.35	6.93	16.25	5.06	<0.001
C3–4	−1.92	4.63	−3.53	−0.30	−2.42	0.02*
C3–5	−4.49	7.71	−7.18	−1.80	−3.39	<0.001
C3–6	−4.43	11.93	−8.60	−0.27	−2.17	0.04*
C3–7	−2.15	13.32	−6.80	2.50	−0.94	0.35
C3–T1	0.94	13.92	−3.92	5.79	0.39	0.70
C4–5	−1.89	5.65	−3.86	0.08	−1.95	0.06
C4–6	−2.53	10.00	−6.02	0.96	−1.47	0.15
C4–7	−0.87	9.97	−4.35	2.61	−0.51	0.61
C4–T1	1.33	11.32	−2.62	5.28	0.68	0.50
C5–6	−2.50	10.57	−6.19	1.19	−1.38	0.18
C5–7	10.92	8.46	7.97	13.87	7.53	0.00*
C5–T1	2.54	8.79	−0.52	5.61	1.69	0.10
IDA C2–3	0.84	4.22	−0.63	2.32	1.17	0.25
IDA C3–4	4.12	6.48	1.86	6.38	3.71	<0.001
IDA C4–5	−0.06	0.40	−0.20	0.08	−0.86	0.40
IDA C5–6	2.90	6.44	0.65	5.15	2.62	0.01*
IDA C6–7	−0.13	3.90	−1.49	1.23	−0.19	0.85
IDA C7–T1	0.18	4.97	−1.56	1.91	0.21	0.83
AOL	0.15	3.95	−1.23	1.53	0.22	0.83

Significant changes (P≤0.05) are seen in IVAs: FM–C2, FM–C3, FM–C4, C1–2, C1–3, C1–4, C2–7, C2–T1, C3–4, C3–5, C3–6, C5–7. And in IDAs: C3–4, C5–6. *, P values with significant difference between the two values (less than 0.05). AOL, angle of lordosis; FM, foramen magnum; IDA, interdiscal angle; IVA, intervertebral angle.

Discussion

This study examined the impact of smartphone use, specifically texting, on cervical sagittal alignment in healthy young adults. Our findings demonstrate that both standing and sitting while texting result in significant changes in IVA and IDA, particularly in the upper cervical spine. These changes were more pronounced in the seated position, suggesting that posture plays a crucial role in biomechanical stress distribution during smartphone use.

Notably, the most significant deviations were observed in the FM–C2/C3, C1–2, and most C3 angles. This is consistent with prior literature suggesting that the upper cervical spine, due to its smaller vertebral bodies and weaker musculature, is more susceptible to postural loading. While degenerative cervical spondylosis traditionally affects the lower cervical spine (C5–6, C6–7), our findings suggest that repetitive forward-flexed postures during smartphone use may increase the mechanical demand on the upper segments, potentially leading to a shift in degenerative patterns in younger populations (19).

These findings align with recent studies conducted in 2024–2025. Hakami et al. reported that approximately 64% of smartphone users experienced neck pain correlated with excessive use and prolonged cervical flexion, particularly at angles greater than 30 degrees (20). Similarly, a study on university students by Maayah et al. revealed that users who spent more than 4 hours per day on smartphones exhibited significantly greater cervical flexion and reported higher rates of neck and shoulder discomfort (21).

Biomechanically, flexing the neck to 60° increases the effective load on the cervical spine to nearly 60 pounds (4). This excessive strain, when repeated chronically, is likely to exacerbate intervertebral disk stress, especially in the upper segments. Piruta et al. demonstrated in 2025 that muscle activation in the trapezius and deep cervical extensors significantly increases during texting, indicating muscular overload and fatigue (22). Although Kim et al. found no immediate signs of cervical instability in short texting sessions, subjective reports of discomfort support the notion of cumulative microtrauma with chronic exposure (23).

The pronounced effects observed in the seated texting posture can be explained by decreased proprioceptive feedback and a tendency toward spinal slouching while seated. This posture facilitates a longer moment arm and increased anterior shear forces on the cervical segments (24). Furthermore, gait and posture studies have indicated that texting postures also increase thoracic kyphosis and reduce lumbar lordosis, further contributing to spinal misalignment (25,26).

Emerging evidence also points to broader health implications associated with prolonged smartphone use. A 2024 study highlighted that sustained forward head posture not only affects cervical alignment but also contributes to temporomandibular disorders and rotator cuff tendonitis, indicating a systemic impact on musculoskeletal health. Additionally, the cosmetic consequences, such as neck wrinkles and sagging skin, have been linked to chronic neck flexion, emphasizing the multifaceted effects of “tech neck” (27).

Moreover, a 2024 study by Barczyk-Pawelec et al. found that smartphone use leads to a backward displacement of the upper torso and increased angles of cervical spine flexion, particularly in females, suggesting gender-specific postural adaptations during device use (28).

Limitations of this study must be acknowledged. First, the sample size of 34 subjects, while sufficient for detecting significant changes in angles, may limit generalizability. Second, the study used short-duration texting tasks (~10 minutes), which may not reflect long-term habitual use. Third, the participants were instructed to act naturally, but variability in their seated and standing posture could introduce confounding. Additionally, the study population was limited to healthy individuals under age 40 years, which may exclude those more prone to early degenerative changes. Future studies should incorporate long-term follow-up, larger sample sizes, and symptomatic populations to investigate the cumulative effects of smartphone posture and to validate whether early angular deviations translate into measurable clinical or radiographic pathology.

Overall, these findings contribute to a growing body of evidence showing that smartphone usage affects cervical spine biomechanics and may predispose young individuals to musculoskeletal conditions previously uncommon in their age group. There is a pressing need to increase public awareness, implement ergonomic education, and develop preventive strategies for mitigating the musculoskeletal impact of excessive smartphone use.

Conclusions

This study demonstrates, with radiographic evidence, that smartphone texting significantly alters cervical sagittal alignment, particularly in the upper cervical segments and most prominently in the seated posture. These postural changes may contribute to early cervical discomfort and potentially accelerate degenerative processes. As smartphone use becomes increasingly prevalent, especially among younger populations, the musculoskeletal consequences of habitual forward-flexed postures warrant increased clinical attention and preventive measures.

Supplementary

The article’s supplementary files as

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. This study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by ethics committee of Rambam Health Care Campus (No. 0410-20), and informed consent was taken from all the patients.

Data Sharing Statement

Available at https://jss.amegroups.com/article/view/10.21037/jss-24-19/dss

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DOI: 10.21037/jss-24-19