Typing, the Trapezius and Neck Pain

Research Review: Typing, the Trapezius and Neck Pain

By Jinny McGivern DPT, PT, Certified Yoga Instructor

Edited by Brent Brookbush DPT, PT, MS, PES, CES, CSCS, ACSM H/FS

Original Citation: Wegner, S., Jull, G., O’Leary, S., & Johnston, V. (2010). The effect of a scapular postural correction strategy on trapezius activity in patients with neck pain. Manual therapy, 15(6), 562-566. ABSTRACT

The many faces of "sub-optimal" sitting posture, a frequent precursor to neck pain. Image courtesy of http://keyfitnesstraining.com/online-courses/online-courses/relieving-pain-from-poor-posture

Why is this relevant?: Previous research has reported the incidence of neck pain in office workers to be as high as 45% (Cagnie et al., 2007). This article examined the behavior of the trapezius muscle (upper, middle & lower sections) during the performance of the typical office task of typing. It has been hypothesized that the trapezius muscle demonstrates altered behavior in individuals with neck pain; however, consensus regarding those alterations has not been reached. The authors also examined the impact of an intervention aimed at postural correction on the behavior of the trapezius muscle during a typing task.

Study Summary

Image courtesy of http://www.triggerpointtherapist.com/online-courses/online-courses/blog/trapezius-trigger-points/trapezius-trigger-points-everybody-has-one/

Review & Commentary:

There are many features of this research that contribute to its strong methodology. The authors used a power analysis to determine the number of subjects that they would need to give results with a statistical power of .92. They selected typing, a very common activity in the 21st century and one that has often been implicated as an aggravating activity for neck pain, as the functional task to examine. For the placement of electrodes on the 3 portions of trapezius , a previously validated protocol was utilized. The authors clearly defined "good" and "bad" scapular position. "Good" scapula position was described as a position in the mid-range of all available scapula motions - upward/downward rotation, medial/lateral rotation, anterior/posterior tipping, protraction/retraction. "Poor" scapular posture was defined as any deviation from the mid range of any of the above motions. Finally, the authors chose to compare raw EMG data between the NP & PFC groups. This was an important decision that helped to eliminate potential error related to normalizing data to max voluntary contraction (MVC). It is possible that individuals with pain are unable to produce an MVC in the same way as individuals without pain.

Like all research, this study has limitations. Scapula position was assessed visually by one of the investigators. While this is often the method of assessment in the clinic, it may be beneficial if future researchers use a motion analysis system to provide more precise information on the position of what was deemed "good" versus "poor" scapular position and how they differ. Subjects were selected based on falling into a category of neck pain with "poor" scapular position, or no neck pain with "good" scapular position. Future researchers should examine the incidence of "poor" scapular posture in subjects with neck pain to shed additional information on how often these two dysfunctions occur simultaneously. The trapezius muscle was the only muscle assessed. Future researchers should examine the impact of other muscles that attach to the scapula on its alignment during a typing task. It is important to note that the NP group did not report very high levels of pain or disability (mean NDI = 20.5; mean VAS 2.0cm). The results of this study may have limited generalizability to individuals with more severe pain and/or higher levels of disability. It is important to note that the chair used to complete the typing task did not have arm support. Because of the anatomical connections between the cervical spine and the shoulder girdle via the trapezius, future researchers may want to consider the impact of upper extremity support on trapezius activity. During the intervention phase of this study, the postural correction was customized to address the specific components of scapular malalignment for each individual. Each subject's scapular position was corrected if they started to lose it during the typing task. It would have been helpful if information was provided on how often scapular position needed to be adjusted to give human movement professionals a sense of how much training was needed for clients in this task before they could sustain the correction for any period of time. This research did not examine any long term outcomes of this postural correction. Could individuals reproduce this correction independently and achieve the same changes in trapezius neuromuscular activation?

While this research has expanded our knowledge of the activity of the trapezius muscle in those with and without neck pain during a typing task, it also has opened the door to new questions. It would have been helpful if the researchers provided more detailed information on the NP group's pain experience in their daily lives and also throughout the events of the study. Did they have pain at rest or with activity? Which activities? Did typing elicit pain? If pain with activity, how long does the pain take to come on? If pain with static positioning, how long before pain comes on? Most importantly, did altered neuromuscular activity have any impact on the subject's pain experience? As a physical therapist, I can appreciate an optimal scapula position on principle of achieving efficient posture. Patients/clients adopt an exercise habit when it changes pain or enhances their function/performance. Future research should examine the relationship between pain, altered neuromuscular activity and scapula position.

Why is this study important?

This study provides evidence that postural corrections can be used to reduce neuromuscular dysfunction of the trapezius muscle in individuals with neck pain in the short term. Improved neuromuscular efficiency has the potential to reduce pain; however, additional research is needed to fully understand this relationship.

How does it affect practice?

This research re-iterates the importance of understanding what good posture looks like and appreciating the different components of muscle activity/length that contribute to it. The authors of this study utilized a manual correction to improve the position of the scapula and cuing to aid subjects in maintaining the position. The human movement professional may want to consider - What can I do to make it more possible for my patient/client to maintain a "good" scapula position? What combination of release techniques, stretching, and activation activities would set the stage for a more optimal scapula position for a specific individual? Cognitive training can only go so far (the subjects in this study were unable to maintain the correction for even 5 minutes). It is essential to help the client/patient to correct muscle/structural imbalances via manual techniques and/or corrective exercise (as appropriate for the client & within the scope of the practitioner's practice) in order to create a more optimal environment for optimal posture to occur.

How does it relate to Brookbush Institute Content?

It has been proposed by the Brookbush Institute that neck pain may be a consequence of the neuromuscular and structural imbalances described by the Upper Body Dysfunction (UBD) predictive model of postural dysfunction . This research examined the trapezius muscle, one of the muscles implicated as being dysfunctional in UBD . The primary neuromuscular differences in the various parts of the trapezius between the NP group and PFC group were that the NP group demonstrated increased activity of the middle trapezius and reduced activity of the lower trapezius . The UBD model describes the lower trapezius as having a tendency to become long and overactive, thus there is congruence between theory and research in this aspect. The middle trapezius has not been implicated in the UBD model to be either under or over active, although this research indicates that it may became overactive in symptomatic individuals (a possible compensation for reduced activity of the lower trapezius ?). The UBD model describes the upper trapezius as having a propensity to become under-active as an upward rotator in the early stages of UBD , but then may become short and overactive in the later stages of UBD . This research did not find significant differences in the upper trapezius between the NP & PFC groups. It is possible that this was the case because the typing task took place with the upper extremity in a neutral position in the frontal plane where no upward rotation was needed. Below are a series of videos that discuss how the Brookbush Institute recommends addressing tapezius trapezius . The first 2 videos demonstrate activation techniques to improve scapular upward rotation, while the following 2 videos describe release and stretch techniques that may be necessary in individuals with longstanding UBD .

Trapezius Isolated Activation

Trapezius Reactive Activation

Upper Trap SA Static Release

Upper Traps SA Statc Stretch

Additional References:

Cagnie, B., Danneels, L., Van Tiggelen, D., De Loose, V., & Cambier, D. (2007). Individual and work related risk factors for neck pain among office workers: a cross sectional study. European Spine Journal, 16(5), 679-686.

Szeto, G. P., Straker, L. M., & O’Sullivan, P. B. (2005). A comparison of symptomatic and asymptomatic office workers performing monotonous keyboard work—1: neck and shoulder muscle recruitment patterns. Manual therapy, 10(4), 270-280.

© 2014 Brent Brookbush

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