BENEFITS OF CORRECT POSTURES FOR BETTER LEARNING By Preety Agarwal[1]

 

 Abstract

Good posture involves having a relaxed appearance and a “neutral spine.” A neutral spine retains three natural curves: a small hollow at the base of the neck, a small roundness at the middle back, and a small hollow in the lower back. Many people overcompensate for bad posture by standing too straight, thus eliminating the natural curves of the spine. When our posture is correct, the ears, shoulders, hips, knees, and ankles should align in one straight line. To give you a mental image of what good posture looks like, imagine hanging a plumb line from your earlobe.  If your posture is correct, the line would hang straight to the middle of the anklebone. If you’re not a mental imagery kind of guy, perform this “wall test.” Stand with head, shoulders, and back against the wall and your heels about 5-6 inches forward. Draw in the lower abdominal muscles, decreasing the arch in your lower back. Push away from the wall and try to maintain this upright, vertical alignment. That’s good posture. Having excellent posture can lead to a lot of great benefits, like lowering your stress level, but it can also affect how well you learn and remember new things. Posture is thus a constant; something we are never frees from; but also by its nature something that we rarely give conscious thought to. The exception to this is when different postures cause a change in a healthcare problem. It is known also that different postures affect physiological functions, and that postural possibilities may be affected by pathology. This article will focus on posture and lumbar spine pain; and specifically address these areas:

  • Analyzing posture
  • Affect of posture of anatomy and physiology
  • Normal posture
  • ‘Ideal postures’
  • Affect of sustained postures
  • Is there an optimal posture for sitting?
  • Is sitting a risk factor for low back pain?
  • Are certain sitting postures a risk factor for back pain?
  • Do certain postures aggravate back pain when it is present?
  • Are there postural variations in those with symptoms?

INTRODUCTION

What Is Good Posture? According to a study conducted at Florida State University, researchers found out that “congruent body posture” significantly improved access to and retention of autobiographical memories in both young and adult people (Dijkstra, 2005). Therefore, we can say that posture is in some way affecting our ability to recall specific types of memories. But how so? The suggestion seems to be that when you remember something you are also reminded of the “state” of learning, a concept that not only includes posture but also emotions and surrounding environment. Bad posture can therefore be a hindrance to effective learning merely because we later interpret it as an “incongruent” positioning of the body. Having excellent posture can lead to a lot of great benefits, like lowering your stress level, but it can also affect how well you learn and remember new things.

The definition of posture can be rather vague. A classic ergonomic text book discusses aspects of posture at great length without actually defining it (Pheasant 1998). A more recent ergonomic textbook is slightly more explicit: ‘posture is defined as the average orientation of the body parts over time.’ (Bridger 2003). An undergraduate textbook on human movement also keeps it simple: ‘posture means simply position or alignment of body parts’ (Trew and Everett 2001). A dictionary defines it as ‘the way one holds one’s body while standing, sitting or walking’, or ‘a particular position or attitude of the body’ (Chambers Concise Dictionary 2004). Probably a more useful reflection of aspects of posture is the dimensions considered relevant in analyzing static workloads (Corlett 2005):

  • Angular relations between body parts
  • Distribution of mass of body parts
  • Forces exerted on environment during posture
  • Length of time held in that posture
  • Effects on individual who maintain that posture

All descriptions of posture imply that posture is an active process, rather than a static one. We may remain in relatively static postures for long periods during work, relaxation or sleep, but all of these activities are characterized by intermittent changes in posture. Periods of relatively static posture can be interrupted by periods of vigorous activity, for instance during running, working out at the gym, manual labour, or gardening. ‘Posture cannot be separated from movement, but should be regarded as temporarily arrested movement as it is in a constant state of change, as anyone trying to stay still for any length of time will know’ (Trew and Everett 2001).

Static postures tend to grow more fixed as we age, and our active postures decline. For instance, between childhood and 60s there is nearly a halving of sagittal and frontal plane movements of the lumbar spine (Twomey and Taylor 1994), and there is an age-related decline in participation in exercise, especially amongst women (O’Brien Cousins 1998). Aging can be associated with more fixed postures, such as loss of lumbar extension and exaggerated cervico-thoracic hypnosis because of spondylotic changes or osteoporosis. Inflammatory joint pathologies, such as ankylosing spondylitis and rheumatoid arthritis, can produce dramatically reduced movement (Bland 1994).

Analyzing posture

There are numerous ways of analyzing posture that are explored in detail in ergonomic text books (Pheasant 1998, Bridger 2003, Corlett 2005). These include direct observation, measurement with goniometers, video-computer analysis, subjective measures, such as onset and levels of discomfort from sustained postures and different types of electromyography (Corlett 2005). Obviously the different methods of observation capture different dimensions of the components of posture; some focusing on the angular relations between body parts, some on muscle work, and others on the effect of posture in terms of discomfort.

Affect of posture on anatomy and physiology

Different postures affect the spine in different ways. Bending and sitting is associated with flexion of the lumbar, thoracic and lower cervical spine, unless a very upright sitting posture is maintained, whereas walking and standing is associated with extension or lordosis of the lumbar spine (McKenzie and May 2003). Flexion of the hip and knee causes posterior tilting of the pelvis, which in turn produces a flattening of the lumbar lordosis (Bridger 2003). Thus crossing the legs flattens the lumbar spine. Forces on the spine result from the posture of the spine, muscle activity, and passive support, as from a chair (Adams et al. 2006). The angle of the sitting surface will have implications for the posture of the spine: a downward sloping surface encourages a lordotic posture; a flat seat encourages a flattening of the lordosis, and a very low seat, in which the knees are higher than the hips, encourages flexion of the lumbar spine (Bridger 2003). Different postures alter muscle activity; during standing back muscles show slight, intermittent or no activity, with activity influenced by the position of the spine in reference to the line of gravity (Bogduk 1997). The more off the centre of gravity the more contra-lateral muscle groups will need to work to maintain control. During sitting muscle activity is minimal so loads tend to be transferred to local soft tissues (McKenzie and May 2003).

Postures affect anatomy and physiology. With flexion of the lumbar spine the intervertebral disc is compressed anteriorly, which causes a posterior displacement of the nucleus pulposus, an increase in intra-discal pressure, there is even distribution of stress within the disc, and increased supply of metabolites to the disc. The spinal and vertebral canals are widened, the spinal cord is tensioned, and the load on the zygapophyseal joints is reduced with flexion. Opposite effects occur with extension, as well as reduced pressure on the nucleus pulposus (Adams et al. 2006). These are all normal anatomical changes to these different postures. Prolonged standing causes peripheral pooling of the blood, changes to heart rate and blood pressure, and cessation of the venous muscle pump, which returns blood to the heart (Bridger 2003).

Normal posture

There have been attempts to define types of body posture, but these are generally not useful as individuals have unique anthropometric and physiological profiles (Trew and Everett 2001). Individual variability during the day and inter-individual variability about what is considered ‘normal’ makes this impossible to define. For instance, sitting can range from upright sitting with lumbar support maintaining almost end-range lumbar extension to relaxed slump sitting on the sofa, which might be near end-range lumbar flexion.

‘Ideal postures’

Ideal postures have been defined, mostly related to symmetry of body parts and equilibrium or balance between right and left and posterior and anterior (Trew and Everett 2001). However it is unclear if there are ideal body postures. Asymptomatic asymmetry is not unusual and if not dramatic is not linked to pain or functional limitations. Given the multiple effects of different postures on numerous structures, and the theoretical basis for determining what the ‘ideal posture’ is, not surprisingly there have been conflicting interpretations about this. Some authorities suggest that the lumbar spine should be slightly flexed when sitting (Adams et al. 2002); whereas others suggest that a more lordotic posture is best (Harrison et al. 1999; Pynt et al. 2001; 2008).

Is there an optimal posture for sitting?

There is some debate about the optimal sitting posture. Some experts suggest that sitting in moderate flexed postures is preferable, whereas during walking a slight lordosis has certain advantages (Adams et al. 2006). However too much flexion is worse than a little; and prolonged flexion may compromise the ability of the muscles to protect the lumbar spine. Others have suggested that there are several disadvantages to sitting in flexion and that maintenance of lordosis is best when sitting (Harrison et al. 1999; Pynt et al. 2001; 2008).

A lot of this debate is based on the anatomical and physiological effects of different postures that are outlined above. Several studies suggest that sitting in more flexed postures for sustained periods is more likely to generate discomfort than extended postures (Knutsson et al. 1966; Mandal 1984; Harms-Ringdahl 1986; Eklund and Corlett 1987; Harms 1990; Wormersley and May 2006; Bakker et al. 2007; McGill and Fenwick 2009), though some of the earlier studies have weak study designs. Furthermore those who develop postural back ache sit in more flexion and for longer periods without interruption than those who do not develop this discomfort (Wormersley and May 2006). Ultimately it should be recognized that there may be no single ideal sitting or standing posture. It is clear that any posture maintained for any length of time without interruption will become uncomfortable and even painful. Despite disagreement about what is the optimal sitting position, several reviewers were clear and consistent about the recommendation for regular interruption from any sustained position, and the importance of intermittent postural adjustments (Pynt et al., 2001; Adams et al. 2006).

The Benefits of Good Posture

There are several ways that good posture can improve both mind and body. Below we list a few of them:

Improves organ function. When we’re slouched forward, our rib cage is actually pushing down on our internal organs. All this mashing can cause digestive problems. By having good posture, we keep things nice and open for our intestines to do their work.

Reduces tension and pain in neck, shoulders, and back. If you suffer from chronic pain in your upper body, it may be caused by your poor posture. When you first start practicing good posture, you may feel as though you had less pain and tension when you slouched around all day. But keep at it. You’re retraining your body to have the posture nature intended. After a week of strengthening muscles you probably haven’t worked in awhile, your chronic pain should begin to dissipate.

Increases concentration and mental performance. A study done by Colorado College showed that male students with the best sitting posture scored significantly higher on tests than students who slouched. ((http://www.theatlantic.com/doc/200710/primarysources/2)) Tomi Ann Roberts PhD, lead study author, stated that “an upright posture makes people feel dominant and successful, which in turn improves their ability to relax and focus on problems.” Interestingly, the study showed that only male students benefited academically from improved posture. Good posture didn’t seem to have an effect on women.

Prevents humped shoulders. We often only associate the shoulder hump with little old ladies and Quasimodo. But men can develop a “dowager’s hump,” too. The hump develops through a combination of bad posture and osteoporosis. Osteoporosis is common in older women, but men can also see a significant loss of bone mass as they age. You can help stave off the hump by focusing on maintaining good posture throughout your life (and taking a calcium supplement when you get older).

Prevents “beer belly.” Have you ever seen those old men who have super skinny legs and arms, but then a small or sometimes huge beer belly? Well, there are two factors at play here. First, as we age, our metabolism slows down, and as men, we store more fat in our bellies. This factor can be mitigated by proper diet and exercise. The other factor is- you guessed it- posture. As mentioned above, bad posture causes your rib cage to push down on your organs. Your organs are surprisingly malleable and will consequently protrude out and push against our abdominal wall.

Increased confidence. Remember that Colorado College study we mentioned above? It also said that improved posture increases confidence in men. So next time you’re about to go into a job interview or are about to talk to a woman for the first time, stand up a little straighter to increase your manly swagger.

Posture While Standing

  1. Feet should be shoulder width apart, thigh muscles elongated without locking the knees back. Maintain most of your weight on the balls of your feet and not on your heels. When you put your weight on your heels, you create misalignment with your body. A quick test to see if your weight is properly distributed is to have someone gently push on your sternum. If you lose balance easily, then your weight is on your heels. Now try putting more of your weight on the balls of your feet and have someone push you again. You’re probably more stable this time because your body is better aligned.
  2. Maintain a small hollow in your lower back, but avoid the tendency for too much arching or leaning back, especially with prolonged standing. The “tail” should remain slightly tucked down.
  3. Lift your chest. Your shoulder blades should move down and back. This will create a good distance from your hip bone to your rib cage.
  4. Make your chin level. The highest point of your body should be the top back region of your head. Relax your jaw and neck muscles.
  5. Perform the wall test if needed to ensure your posture is good.

Posture While Sitting at a Desk

  1. Feet should be resting on the floor with knees and hips bent 90 degrees. While it may seem more comfortable to cross our feet, this actually screws up our body’s alignment and causes unneeded stress on joints and muscles.
  2. Maintain an arch in the lower back. If you are unsure how much arch is “good,” go from a slouched position up to the extreme end range of erect posture. Now back off 10-15%. This is the neutral position for your lower back.
  3. Lift your chest. Picture a string tied to the 2nd or 3rd top button on a shirt pulling straight up to the ceiling.
  4. Make your chin level. If it helps, picture a book on your head. The highest point of your body should be the top back region of your head.
  5. Avoid slouching or leaning forward, especially when tired from sitting in the office chair for long periods.
  6. Take frequent breaks. At first, trying to sit up straight in a chair can be tiring. After years of slouching, your body has probably created a new “bad” posture for itself, and it’s going to take some work to get it back to the way it should be. Take it slow from the beginning. Sit straight for 20 minutes and get up and take a break. Walk around; reach your hands towards the sky, and stretch. Sit down again and get back to work. Take another break 20 minutes later.

Keep Your Posture in Check

Maintaining good posture is definitely not easy. We can’t be thinking about it all the time. We may start off the day sitting upright, but a little while later; we’re lost in our work and slouching down. Here’s a easy way to remind yourself to work on your posture:

  1. Tie one end of a string to the top button on your shirt.
  2. Tie the other end of the string to your belt buckle, so that the string is taut when you’re sitting upright.
  3. Whenever the string goes slack, you know you’re slouching. Sit up and restore your good posture.

CONCLUSIONS

Posture is a complex issue, the definition frequently vague, and multiple variables are relevant when considering the issue. Posture is with us all the time and is generally ignored, but we know it affects anatomy and physiology. The most important variables are probably related to sustained postures and the effect these might have on an individual. The evidence about its role in provoking musculoskeletal symptoms and as a risk factor for back pain is weak. However it is clear that specific postures, most commonly ones of flexion, commonly aggravate back pain when present. The inconclusiveness of previous research about the relevance of posture and back pain may relate to the heterogeneous back pain population. Aggravating postures may be particular to certain sub-groups of the low back pain population.

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[1] Asst.Prof.Dept.Of Teacher Education, Pt.J.N.PG.College, Banda.U.P.