Posture and mood: implications and applications to health and therapy
Posted: November 28, 2017 Filed under: Neck and shoulder discomfort, posture, self-healing, Uncategorized | Tags: back pain, electromyography, ergonomics, neck and shoulder tension, posture, spinal alignment, stress management 5 CommentsThis blog has been reprinted from: Peper, E., Lin, I-M, & Harvey, R. (2017). Posture and mood: Implications and applications to therapy. Biofeedback.35(2), 42-48.
Slouched posture is very common and tends to increase access to helpless, hopeless, powerless and depressive thoughts as well as increased head, neck and shoulder pain. Described are five educational and clinical strategies that therapists can incorporate in their practice to encourage an upright/erect posture. These include practices to experience the negative effects of a collapsed posture as compared to an erect posture, watching YouTube video to enhance motivation, electromyography to demonstrate the effect of posture on muscle activity, ergonomic suggestions to optimize posture, the use of a wearable posture biofeedback device, and strategies to keep looking upward. When clients implement these changes, they report a more positive outlook and reduced neck and shoulder discomfort.
Background
Most people slouch without awareness when looking at their cellphone, tablet, or the computer screen (Guan et al., 2016) as shown in Figure 1. Many clients in psychotherapy and in biofeedback or neurofeedback training experience concurrent rumination and depressive thoughts with their physical symptoms. In most therapeutic sessions, clients sit in a comfortable chair, which automatically creates a posterior pelvic tilt and encourages the spine to curve so that the client sits in a slouched position. While at home, they sit on an easy chair or couch, which lets them slouch as they watch TV or surf the web.
Figure 1. (A). Employee working on his laptop. (B). Boy with ADHD being trained with neurofeedback in a clinic. (C). Student looking at cell phone. When people slouch and look at the screen, they tend to slouch and scrunch their neck.
In many cases, the collapsed position also causes people to scrunch their necks, which puts pressure on their necks that may contribute to developing headache or becoming exhausted. Repetitive strain on the neck and cervical spine may trigger a cervical neuromuscular syndrome that involves chronic neck pain, autonomic imbalance and concomitant depression and anxiety (Matsui & Fujimoto, 2011), and may contribute to vertebrobasilar insufficiency –a reduction in the blood supply to the hindbrain through the left and right vertebral arteries and basilar arteries (Kerry, Taylor, Mitchell, McCarthy, & Brew, 2008). From a biomechanical perspective, slouching also places more stress is on the cervical spine, as shown in Figure 2. When the neck compression is relieved, the symptoms decrease (Matsui & Fujimoto, 2011).
Figure 2. The more the head tilts forward, the more stress is placed on the cervical spine. Reproduced by permission from: Hansraj, K. K. (2014). Assessment of stresses in the cervical spine caused by posture and position of the head. Surgical Technology International, 25, 277–279.
Most people are totally unaware of slouching positions and postures until they experience neck, shoulder, and/or back discomfort. Neither clients nor therapists are typically aware that slouching may decrease energy levels and increase the prevalence of negative (hopeless, helpless, powerless, or defeated) memories and thoughts (Peper & Lin, 2012; Peper et al, 2017)
Recommendations for posture awareness and training in treatment/education
The first step in biofeedback training and therapy is to systematically increase awareness and training of posture before attempting further bio/neurofeedback training and/or cognitive behavior therapy. If the client is sitting in a collapsed position in therapy, then it will be much more difficult for them to access positive thoughts, which interferes with further training and effective therapy. For example, research by Tsai, Peper, & Lin (2016) showed that engaging in positive thinking while slouched requires greater mental effort then when sitting erect. Sitting erect and tall contributes to elevated mood and positive thinking. An upright posture supports positive outcomes that may be akin to the beneficial effects of exercise for the treatment of depression (Schuch, Vancampfort, Richards, Rosenbaum, Ward, & Stubbs., 2016).
Most people know that posture affects health; however, they are unaware of how rapidly a slouching posture can impact their physical and mental health. We recommend the following educational and clinical strategies to teach this awareness.
- Practicing activities that raise awareness about a collapsed posture as compared to an erect posture
Guide clients through the practices so that they experience how posture can affect memory recall, physical strength, energy level, and possible triggering of headaches.
A. The effect of collapsed and erect posture on memory recall. Participants reported that it is much easier evoke powerless, hopeless, helpless, and defeated memories when sitting in a collapsed position than when sitting upright. Guide the client through the procedure described in the article, How posture affects memory recall and mood (Peper, Lin, Harvey, and Perez, 2017) and in the blog Posture affects memory recall and mood.
B. The effects of collapsed and erect posture on perceived physical strength. Participants experience much more difficulty in resisting downward pressure at the wrist of an outstretched arm when slouched rather than upright. Guide the client through the exercise described in the article, Increase strength and mood with posture (Peper, Booiman, Lin, & Harvey, 2016) and the blog, Increase strength and mood with posture.
C. The effect of slouching versus skipping on perceived energy levels. Participants experience a significant increase in subjective energy after skipping than walking slouched. Guide the client through the exercises as described in the article, Increase or decrease depression—How body postures influence your energy level (Peper & Lin, 2012).
D. The effect of neck compression to evoke head pressure and headache sensations. In our unpublished study with students and workshop participants, almost all participants who are asked to bring their head forward, then tilt the chin up and at the same time compress the neck (scrunching the neck), report that within thirty seconds they feel a pressure building up in the back of the head or the beginning of a headache. To their surprise, it may take up to 5 to 20 minutes for the discomfort to disappear. Practicing similar awareness activities can be a useful demonstration for clients with dizziness or headaches to experience how posture can increase their symptoms.
- Watching a Youtube video to enhance motivation.
Have clients watch Professor Amy Cuddy’s 2012 TED (Technology, Entertainment, and Design) Talk, Your body language shape who you are, which describes the hormonal changes that occur when adapting a upright power versus collapsed defeated posture.
- Electromyographic (EMG) feedback to demonstrate how posture affects muscle activity.
Record EMG from muscles such as around the cervical spine, trapezius, frontalis, and masseters or beneath the chin (submental lead) to demonstrate that having the head is forward and/or the neck compressed will increase EMG activity, as shown in Figure 3.
Figure 3. Electromyographic recording of the muscle under the chin while alternating between bringing the head forward or holding it back, feeling erect and tall.
The client can then learn awareness of the head and neck position. For example, one client with severe concussion experienced significant increase in head pressure and dizziness when she slouched or looked at a computer screen as well as feeling she would never get better. She then practiced the exercise of alternating her awareness by bringing her head forward and then back, and then bringing her neck back while her chin was down, thereby elongating the neck while she continued to breathe. With her head forward, she would feel her molars touching and with her neck back she felt an increase in space between the molars. When she elongated her neck in an erect position, she felt the pressure draining out of her head and her dizziness and tinnitus significantly decrease.
- Assessing ergonomics to optimize posture.
Change the seated posture of both the therapist and the client during treatment and training. Although people may be aware of their posture, it is much easier to change the external environment so that they automatically sit in a more erect power posture. Possible options include:
A. Seat insert or cushions. Sit in upright chairs that encourage an anterior pelvic tilt by having the seat pan slightly lower in the front than in the back or using a seat insert to facilitate a more erect posture (Schwanbeck, Peper, Booiman, Harvey, & Lin, 2015) as shown in Figure 4.
Figure 4. An example of how posture can be impacted covertly when one sits on a seat insert that rotates the pelvis anteriorly (The seat insert shown in the diagram and used in research is produced by BackJoy™).
B. Back cushion. Place a small pillow or rolled up towel at the kidney level so that the spine is slight arched, instead of sitting collapsed, as shown in Figure 5.
Figure 5. An example of how a small pillow, placed between the back of the chair and the lower back, changes posture from collapsed to erect.
C. Check ergonomic and work site computer use to ensure that the client can sit upright while working at the computer. For some, that means checking their vision if they tend to crane forward and crunch their neck to read the text. For those who work on laptops, it means using either an external keyboard, a monitor, or a laptop stand so the screen is at eye level, as shown in Figure 6.
Figure 6. Posture is collapsed when working on a laptop and can be improved by using an external keyboard and monitor. Reproduced by permission from: Bakker Elkhuizen. (n.d.). Office employees are like professional athletes! (2017).
- Wearable posture biofeedback training device
The wearable biofeedback device, UpRight™, consists of a small sensor placed on the spine and works as an app on the cell phone. After calibration the erect and slouched positions, the posture device gives vibratory feedback each time the participant slouches, as shown in Figure 7.
Figure 7. Illustration of a posture feedback device, UpRight™. It provides vibratory feedback to the wearer to indicate that they are beginning to slouch.
Clinically, we have observed that clients can learn to identify conditions that are associated with slouching, such as feeling tired, thinking depressive/hopeless thoughts or other situations that evoke slouching. When people wear a posture feedback device during the day, they rapidly become aware of these subjective experiences whenever they slouch. The feedback reminds them to sit in an erect position, and they subsequently report an improvement in health (Colombo et al., 2017). For example, a 26-year-old man who works more than 8 hours a day on computer reported, “I have an improved awareness of my posture throughout my day. I also notice that I had less back pain at the end of the day.”
- Integrating posture awareness and position changes throughout the day
After clients have become aware of their posture, additional training included having them observe their posture as well and negative changes in mood, energy level or tension in their neck and head. When they become aware of these changes, they use it as a cue to slightly arch their back and look upward. If possible have the clients look outside at the tops of trees and notice details such as how the leaves and branches move. Looking at the details interrupts any ongoing rumination. At the same time, have them think of an uplifting positive memory. Then have them take another breath, wiggling, and return to the task at hand. Recommend to clients to go outside during breaks and lunchtime to look upward at the trees, the hills, or the clouds. Each time one is distracted, return to appreciate the natural patterns. This mental break concludes by reminding oneself that humans are like trees.
Trees are rooted in the earth and reach upward to the light. Despite the trauma of being buffeted by the storms, they continue to reach upward. Similarly, clouds reflect the natural beauty of the world, and are often visible in the densest city environment. The upward movement reflects our intrinsic resilience and growth. –Erik Peper
Have clients place family photos and art slightly higher on the wall at home so they automatically look upward to see the pictures. A similar strategy can be employed in the office, using art to evoke positive feelings. When clients integrate an erect posture into their daily lives, they experience a more positive outlook and reduced neck and shoulder discomfort.
Compliance with Ethical Standards:
Conflict of Interest: Author Erik Peper has received donations of 15 UpRight posture feedback devices from UpRight (http://www.uprightpose.com/) and 12 BackJoy seat inserts from Backjoy (https://www.backjoy.com) for use in research. Co-authors I-Mei Lin and Richard Harvey declare that they have no conflict of interest.
This report evaluated a convenience sample of a student classroom activity related to posture and the information was anonymous collected. As an evaluation of a classroom activity, this report of findings was exempted from Institutional Review Board oversight
References:
Bakker Elkhuizen. (n.d.). Office employees are like professional athletes! (2017). Retrieved from https://www.bakkerelkhuizen.com/knowledge-center/whitepaper-improving-work-performance-with-insights-from-pro-sports/
Cuddy, A. (2012). Your body language shapes who you are. Technology, Entertainment, and Design (TED) Talk, available at: www.ted.com/talks/amy_cuddy_your_body_language_shapes_who_you_are
We thank Frank Andrasik for his constructive comments.
Cellphone harm: Cervical spine stress and increase risk of brain cancer
Posted: November 20, 2014 Filed under: Uncategorized | Tags: cancer, cell phones, ergonomics, health, microwaves, neck pain, posture, shoulder pain, wireless 2 CommentsIt is impossible to belief that that only a few years ago there were no cell phones.
When I go home, I purposely put the phone away so that I can be present with my children.
I just wonder if the cell phone’s electromagnetic radiation could do harm?
Cell phone use is ubiquitous since information is only a key press or voice command away. Students spend about many hours a day looking and texting on a cell phone and experience exhaustion and neck and shoulder discomfort (Peper et al, 2013). Constant use may also have unexpected consequences: Increased stress on the cervical spine and increased risk for brain cancer.
Increased cervical spine stress
As we look at the screen, text messages or touch the screen for more information, we almost always bend our head down to look down. This head forward position increases cervical compression and stress. The more the head bends down to look, the more the stress in the neck increases as the muscles have to work much harder that hold the head up. In a superb analysis Dr. Kennth Hansraj, Chief of Spine Surgery 0f New York Spine Surgery & Rehabilitation Medicine, showed that stress on the cervical spine increases from 10-12 lbs when the head is in its upright position to 60 lbs when looking down.
Figure 1. Stress on the cervical spine as related to posture. (From: Hansraj, K. K. (2014). Assessment of stresses in the cervical spine caused by posture and position of the head. Surgical technology international, 25, 277-279.)
Looking down for a short time period is no problem; however, many of us look down for extended periods. This slouched collapsed position is becoming the more dominant position. A body posture which tends to decrease energy, and increase hopeless, helpless, powerless thoughts (Wilson & Peper, 2004; Peper & Lin, 2012). The long term effects of this habitual collapsed position are not know–one can expect more neck and back problems and increase in lower energy levels.
increased risk for brain cancer and inactive sperm and lower sperm count
Cell phone use not only affect posture, the cell phone radio-frequency electromagnetic radiation by which the cell phone communicates to the tower may negatively affect biological tissue. It would not be surprising that electromagnetic radiation could be harmful; since, it is identical to the frequencies used in your microwave ovens to cook food. The recent research by Drs Michael Carlberg and Lennart Hardell of the Department of Oncology, University Hospital, Örebro, Sweden, found that long term cell phone use is associated by an increased risk of developing malignant glioma (brain cancers) with the largest risk observed in people who used the cell phone before the age of 20. In addition, men who habitually carry the cell phone in a holster or in their pocket were more likely to have inactive or less mobile sperm as well as a lower sperm count.
What can you do:
Keep an upright posture and when using a cell phone or tablet. Every few minutes stretch, look up and reach upward with your hands to the sky.
Use your speaker phone or ear phones instead of placing the phone against your head.
Enjoy the cartoon video clip, Smartphone Ergonomics – Safe Tips – Mobile or Smart Phone Use while Driving, Traveling on the Move.
References:
Agarwal, A., Singh, A., Hamada, A., & Kesari, K. (2011). Cell phones and male infertility: a review of recent innovations in technology and consequences. International braz j urol, 37(4), 432-454. http://www.isdbweb.org/documents/file/1685_8.pdf
Carlberg, M., & Hardell, L. (2014). Decreased Survival of Glioma Patients with Astrocytoma Grade IV (Glioblastoma Multiforme) Associated with Long-Term Use of Mobile and Cordless Phones. International journal of environmental research and public health, 11(10), 10790-10805. http://www.mdpi.com/1660-4601/11/10/10790/htm
De Iuliis, G. N., Newey, R. J., King, B. V., & Aitken, R. J. (2009). Mobile phone radiation induces reactive oxygen species production and DNA damage in human spermatozoa in vitro. PloS one, 4(7), e6446.
Hansraj, K. K. (2014). Assessment of stresses in the cervical spine caused by posture and position of the head. Surgical technology international, 25, 277-279.
Peper, E. & Lin, I-M. (2012). Increase or decrease depression-How body postures influence your energy level. Biofeedback, 40 (3), 126-130.
Peper, E., Waderich, K., Harvey, R., & Sutter, S. (2013). The Psychophysiology of Contemporary Information Technologies Tablets and Smartphones Can Be a Pain in the Neck. In Applied Psychophysiology and Biofeedback, 38(3), 219.
Wilson, V.E. and Peper, E. (2004). The Effects of upright and slumped postures on the generation of positive and negative thoughts. Applied Psychophysiology and Biofeedback.29 (3), 189-195.
Adjust your world to fit you: Become the unreasonable person!*
Posted: November 12, 2014 Filed under: Uncategorized | Tags: computer, ergonomics, muscle tension, neck pain, posture 2 Comments“Reasonable people adapt themselves to the world; unreasonable people persist in trying to adapt the world to themselves. Therefore all progress depends on unreasonable people.”
–Paraphrased from Bernard Shaw
Photo by Erik Peper
Having the right equipment and work environment will reduce injury and improve performance. This is true for athletes as well as for people using computers, laptops, tablets and smartphones. We look down and curve our upper spine to read the tablet, crane our heads forward to read the screen, lift our shoulders, arms and hands up to the laptop keyboard to enter data, and we bend our heads down and squint to read the smartphone—all occurring without awareness (Straker et al, 2008; Asunda, Odell, Luce, & Dennerlein, 2010; Peper et al, 2014). We are captured by the devices and stay immobilized until we hurt. At the end of the work day, we are often exhausted and experience neck and shoulder stiffness, arm pain and eye fatigue. This stress immobility syndrome is the twenty first century reward for digital immigrants and natives.
We hurt because we fit ourselves to the environment instead of changing the environment to fit us. The predominant slouched position even affects our mood and strength (Peper and Lin, 2012). Experience how your strength decreases when you slouch and look downward as compared when you sit tall with your spine lengthened at your laptop, tablet or phone. You will need a partner to do this practice as shown in Figure 1.
Sit in your slouched position while looking down and extend your arm to the side. Have your partner stand behind you and gently press downward on your upper arm near your wrist while you attempt to resist the pressure. Now relax and let your arms hang along the side of your body. Now sit upright in a tall position with your spine lengthening while looking straight ahead. Again extend your arm and gently have your gently press downward on your upper arm near your wrist while you attempt to resist the pressure.
Figure 1. Measuring the ability to resist the downward pressure on the forearm while sitting in either slouched or tall position.
You probably experienced significantly more strength resisting the downward pressure when sitting erect and tall than when sitting collapsed as we discovered in our study at San Francisco State University in with students as shown in figure 2.
Figure 2. Change in perceived strength resisting a downward pressure on the extended arm while sitting. Reproduced by permission from Schwanbeck, R., Peper, E., Booiman, A., Harvey, R., and Lin, I-M. (in press).
Increase your power and take charge! Arrange your laptop, computer and tablet so it fits you. This usually means changing your home and office chairs and desks; since, they have been manufactured for the average person. Just like the average coach airplane seat – it is uncomfortable for most people. As my colleague Annette Booiman who is a Mensendiek practitioner has pointed out, “An incorrectly adjusted chair or table height will force you to work in a dysfunctional body position while an appropriately adjusted chair or table height offers you the opportunity to work in a healthy position.”
Become the unreasonable person and fit the world so that you are comfortable while using digital devices. There are solutions! Take responsibility and adjust your posture to a healthy one–it will make your life so much more energetic. Sit on your sit bones (ischial tuberosities) as if they are the feet of your pelvis and feel your spine lengthening as you sit tall. Alternatively, stand while working and adjust the desk height for your size. Regardless of whether you sit or stand while working, take many breaks to interrupt your immobilized posture. Install a software program on computer to remind you to take breaks and watch the YouTube clips on cartoon ergonomics for working at the computer.
Implement the following common sense ergonomic guidelines:
For working at a computer sit in a chair with your feet on the floor, the elbows bend at 90 degrees with the hands, wrists, and forearms are straight, in-line and roughly parallel to the floor so that the hands can be on the keyboard while the top of monitor is at eye brow level as shown in Figure 3.
Figure 3. Optimum position to sit at a computer work station. From: http://bmarthur.files.wordpress.com/2009/03/good-posture-how-to-sit-at-a-desk.png
For working with a laptop you will always compromise body position. If the screen is at eye level, you have to bring your arms and hands up to the keyboard, or, more commonly, you will look down at the screen while at the same time raising your hands to reach the keyboard. The solution is to use an external keyboard so that the keyboard can be at your waist position and the laptop screen eye level as shown in Figure 4.
Figure 4. Optimum position to sit while using a laptop. From: http://www.winwin-tech.com/uploadfile/cke/images/6.jpg
For working with tablets and smart phones you have little choice. You either look down or reach up to touch the screen. As much as possible tilt and raise the tablet so that you do not have slouch to see the screen.
If you observe that you slouch and collapse while working, invest in an adjustable desk that you can raise or lower for your optimum height. An adjustable height desk such as the unDesk offers the opportunity to change work position from sitting to standing as shown in Figure 5.
Figure 5. Example of a height adjustable desk (the unDesk) that can be used for sitting and standing.
Although office chairs can give support, we often slouch in them. While at home we use any chair that is available—again encouraging slouching. Reduce the slouching by sitting on a seat insert such as a BackJoy® which tends to let you sit more erect and in a more powerful and energizing position see Figure 6.
Figure 6. Example how BackJoy® seat inserts allows you to sit more erect. Reproduced with permission from: http://www.backjoy.com/sit/
Finally, whether or not you can change your environment, take many, many short movement breaks– wiggle, stretch, get up and walk–to interrupt the muscle tension and allow yourself to regenerate. To remind yourself to take breaks while being captured by your work, install a reminder program on your computer such as Stretchbreak that pops up on the screen and guides you through short stretches to regenerate.
Suggested sources:
Cartoon videos on ergonomics: https://peperperspective.com/2014/09/30/cartoon-ergonomics-for-working-at-the-computer-and-laptop/
Healthy computing tips: http://biofeedbackhealth.files.wordpress.com/2013/01/health-computing-email-tips.pdf
Seat insert such as BackJoy®: http://www.backjoy.com/sit/
Height adjustable desk such as The unDesk: http://www.theundesk.com/
Interrupt computer program such as Stretchbreak: http://www.paratec.com
References:
Asundi, K., Odell, D., Luce, A., & Dennerlein, J. T. (2010). Notebook computer use on a desk, lap and lap support: Effects on posture, performance and comfort. Ergonomics, 53(1), 74-82.
Peper, E., & Lin, I. M. (2012). Increase or decrease depression-How body postures influence your energy level. Biofeedback, 40 (3), 126-130.
Peper, E., Booiman, A., Lin, I-M., & Shaffer, F. Making the Unaware Aware-Surface Electromyography to Unmask Tension and Teach Awareness. Biofeedback, 2(1), 16-23.
Schwanbeck, R., Peper, E., Booiman, A., Harvey, R., and Lin, I-M. Posture changes with a seat insert: Changes in strength and implications for breathing and HRV. Poster submitted for the 46th Annual Meeting of the Association for Applied Psychophysiology and Biofeedback.
Straker, L. M., Coleman, J., Skoss, R., Maslen, B. A., Burgess-Limerick, R., & Pollock, C. M. (2008). A comparison of posture and muscle activity during tablet computer, desktop computer and paper use by young children. Ergonomics, 51(4), 540-555.
* Adapted from: Peper, E. (in press). Become the unreasonable person: Adjust your world to fit you! Western Edition and Schwanbeck, R., Peper, E., Booiman, A., Harvey, R., and Lin, I-M. (in press). Posture changes with a seat insert: Changes in strength and implications for breathing and HRV.
Optimizing ergonomics: Adapt the world to you and not the other way around
Posted: February 24, 2014 Filed under: Uncategorized | Tags: ergonomics, muscle tension, posture, stress, Workstyle 1 CommentHaving the right equipment doesn’t mean we use it correctly. It turns out that usage patterns matter just as much as fancy new office furniture. This post was inspired by a wonderful article that David Kadavy generously interviewed me for. His article explores split keyboards and working wellness. In this post, I go in-depth on some complimentary workplace tools and techniques.
After working on a laptop, smartphone or computer, many people experience discomfort and exhaustion. Back and neck pain and vision problems are very common. Although there are many components that contribute to maintaining health and productivity with digital devices, two factors stand out:
- Ergonomic arrangement: the way the physical environment forces the person to adapt, such as bending over to read and perform data entry with a tablet.
- Work style: the way the person manages themselves to perform the tasks.
Many problems that are aggravated or caused by inappropriate ergonomics can be compensated by changing workstyle. For example, if you bend forward to read the tablet or squint to see the text on the monitor, you can take many movement and stress reduction breaks to compensate for the challenging ergonomics. Having the right equipment, appropriately adjusted, is the focus of ergonomics. Working so that health is maintained regardless of equipment is the focus of work style.
Shoes are a great example. Healthy shoes would look like duck feet–wider at the ball of the feet and toes and narrower at the heel. However, most shoes have pointy or narrow toe boxes. Over time, incorrect footwear becomes a major cause of bunions, foot, hip and back pain for older adults. It causes physical deformity just as the 19th century Chinese practice of foot-binding crippled many women. If you want to run a 100 meter race or a marathon—running shoes are better than high heels. Adapting the environment to you instead of the other way around is the underlying theme of ergonomics.
But even with correctly fitting shoes many people still experience discomfort. Often this is because of misaligned movement patterns. such as their feet point outward while walking instead of pointing ahead. Or they unknowingly favor one leg over the other because many years earlier they broke that leg and adapted their walking pattern to reduce the pain. After walking to avoid pain for a month, this new dysfunctional pattern became habitual and their gait never returned to normal. Changing how you walk or work is the focus of optimum work style. For useful suggestions about workstyle see Healthy Computer Email Tips by Erik Peper.
Many experts have worked for decades on defining optimal ergonomics for using digital devices. The results are always compromises because human beings did not evolve to sit in a chair for hours without movement or read from a small screen in front of them. Nevertheless, the ergonomic setup while using laptops and tablets can be significantly improved. It is impossible to achieve a healthy ergonomic setup while using a laptop or tablet. If the screen is placed so that is easily readable, then the fingers and hands need to be lifted (which often involves lifting the shoulders) to perform data entry. On the other hand if the keyboard is at the appropriate height then you have to look down on the screen. If you regularly use a laptop or tablet, consider purchasing a separate monitor and/or keyboard to improve your setup.
And if you’re replacing your keyboard, make sure to check out David Kadavy’s excellent blog: This weird keyboard may be the biggest thing since your standing desk.
the peper perspective 
