Pain in the neck: Some thoughts on how to ensure this does not happen in class or practice

photo from wikipaedia

I will start this by saying that if you feel any discomfort or pain during or after a yoga class, please discuss it with your teacher.  In general, if you move slowly and tense less and stretch less, I hope that you never feel discomfort.   

In this post I will give a few specific cues that work really well to help ease neck discomfort in daily life and certainly while in yoga postures.  However, I advise that you do not practice anything without the guidance of an experienced teacher, especially if you have an injury.  Instead, I hope you might learn or appreciate some of the ways to ensure you do not experience neck pain in yoga and seek to discuss them with a teacher. 

With that said, last week a teacher noted she had advised a student to move from one style of yoga, where poses were held longer, to a more flowing style of yoga.  The advice was given, in part, on the basis that the student’s neck hurt from holding poses to long. 

The student had some form of pre-existing neck issue and it was proposed that the style of yoga (with long held poses) was exacerbating it. 

While this could be true, and other people might draw the same conclusion, I would be cautious to label a particular style of yoga as the reason a neck condition, in and of itself, would be exacerbated (and the teacher would also have had other reasons for recommending a different style for this student as well, including that she genuinely cared for the student and wanted her to continue a yoga practice and so enjoy the benefits of yoga).

Focusing on the questions of whether the style of yoga was to the main contributing factor, the immediate thoughts that came to my mind were:

• ·      Is the problem holding the pose itself too long or is it the position of the head and neck in that particular pose? 
• ·      What are the arms and armpits doing in the poses and could the position of the arm/shoulder joint complex be contributing to tension in the neck?
• ·      What is she doing with her tongue and jaw?
• ·      How are the mats aligned in the room in the class?

I will talk about each these points in turn below and why they sprung to mind.  They are not necessarily the only things to consider but they are some important ones.

Is the problem holding the pose itself too long or is it the position of the neck in that particular pose? 

This is a really important question to ask. 

Any pose in any style of yoga has the potential to exacerbate neck conditions if you hold the head and neck awkwardly.   The same could be said of lower back conditions and a variety of other health and medical conditions (pregnancy, shoulder injury, knee injury, etc).

For instance, I have compressed and rotated cervical vertebrae.  I know if I hold my head awkwardly any yoga class, whether slow or fast, I will end up uncomfortable and possibly with nerve symptoms such as numbness in my fingers. 

For that matter, I can experience these symptoms if I hold my head awkwardly in daily life.

As an experienced yogi, the risk for me of disturbing my neck is actually heightened in a flowing class if I am unfamiliar with the class or if I do not know what poses to expect or what if coming up and wondering if I am doing the same thing as the teacher. 

All of these things might mean that I keep trying to look at the teacher from the poses while never getting to settle into the pose.  As a result my head and neck would be repeatedly twisting, possibly quickly and awkwardly, to get a view of what the teacher is doing. 

On the other hand, as an experienced yogi in a slower class, with long held postures, at least I have the chance to settle my neck into a comfortable position even if I am unfamiliar with the poses or sequence. 

The key, I think, is to have the appropriate cue about what to do with your head and neck, whether this is a faster or slower moving class. 

Sometimes we assume people know how to hold their head and necks.  And you would certainly think that I, as a teacher, would know how to do so!  But when I am learning something new, sometimes I forget.  There is so much to look at and attend to that you can easily forget how you are holding your head.   

Over time I learned that, as a person with a neck condition, I needed to really attend to neck/head position as a key priority whether or not I am teaching, learning, or just sitting around in daily life.

Again, I re-iterate that this goes for anyone with any condition.  If you had a lower back condition you would probably attend to your needs in the lumbar spine when you were in a pose or learning a pose.  In the same way when I work with pregnant women I think about their needs in constructing a pose and sequence.

Giving clear and appropriate cues to people about how to move and hold their head and neck is vital.  Simon Borg Olivier and Bianca Machliss, in their excellent online courses, talk about the importance of what they call the neck joint complex (consisting of skull and cervical vertebrae and structures). [see http://blog.yogasynergy.com for more information on courses and yoga from Simon and Bianca].

High on their agenda with regards to the neck is helping you understand how to create length and stability on all sides of the neck—front, back, and sides—in posture and movement. 

Three important cues they give are:

• ·      Head down, neck back (chin to the middle of the throat) when taking the head down as though to look downwards or if looking forwards or standing steady.  This creates length at the back of the neck without squashing the front;
• ·      Throat forward, head up when taking the head up as though to look upwards.  This creates length at the front of the neck without squashing the back;
• ·      Chin to the middle of the throat, right ear lifting when turning head to right (or left ear lifted when turning head to the left).  This creates length at the side of the neck when turning.

Bianca with throat forward and chin up when looking up so as not to squash the back of the neck.

It is beyond the scope of this blogpost to give further details and I do not advise practicing without an experienced and knowledgeable teacher.  You can learn a lot by either coming to one of my classes or taking Simon and Bianca’s online courses. 

Perhaps the key is to appreciate that there are specific cues you can give with regards to head and neck position in all postures.  If you do not know them then go to an experienced practitioner and learn from them!

When the student with the neck condition came to class I found she was not quite sure how to hold her head and did not realize the position of her head itself might be contributing to or causing tension. 

When I saw her in various poses it seemed she was holding the neck slightly awkwardly (in this case throat back, head up in downward dog), which was contributing to tension at the back of the neck and upper back. 

Certainly, holding the pose for a long time would have exacerbated the neck condition she already had, especially since she was raising her head against gravity.  However, it looked to me that this could have been prevented if she adjusted her head position while in the pose (in this case to look towards her navel or otherwise to bring head down, neck back).

Simon showing looking to navel in downward dog, which helped the student relieve tension in her neck in that pose.

On this note, while I often use the three important cues in class, I will also often just cue people to move their head and neck softly once in a position and instruct them to ‘find a comfortable position for your neck.’  I also advise people to move from the base of the spine and to move their head last.

Having said this, I am always mindful that some people will not be aware that the position they are currently holding has the potential to create tension over time.   This means I will always tell people in poses like trikonasana and parsvakonasana that the most comfortable position for their neck might be looking down rather than up, and that if they need to come out of the pose then they should do so. 

The important point is holding any pose too long can contribute to tension if you are in an awkward position.  A pose as a whole is made up of all parts of the body and you need to look at all parts of the body to make sure they are not being held awkwardly.  Adjust your position, modify the pose, or come out of the pose if it is not comfortable.  

What are the arms and armpits doing in the poses and could the position of the arm/shoulder joint complex be contributing to tension in the neck?

What you do with your shoulders and arms makes a difference to what you feel in your neck. 

If you are tensing muscles above the shoulder, even subtly, you can end up with pain in the neck.  This will be exacerbated if your head and neck are held awkwardly in the first place. 

Armpit awareness is key here.  I have written a few posts on this previously. 

In general, I would advise you cultivate an approach to your practice where you firm the armpits by lightly pressing them in the direction they are facing.  Again, this is a cue I learned from Simon and Bianca.

When the student came to class I found that she had previously been to a physiotherapist and been given exercises to promote scapular movement and stability.  However, these were not generalized to the postures of yoga and indeed, it is beyond the scope of the physio to tell you this.  

In yoga class then we worked a lot on figuring out how use what she had learned in physio with her yoga poses.  It included figuring out what to do with her arms/shoulders/scapula in a variety of common yoga positions such as arms to side in vira II, arms overhead in down dog, arms to the front in kneeling plank etc.  We focused a lot on armpit activity here. 

In this regard, knowing that arm and shoulder position can influence what you experience in your neck, I also often advise people they do not have to take their arms into a particular position.  For example, I advise to move from the base of the spine up in trikonasana and then to choose whether to keep the top arm on the hip or take it up.

What is she doing with her tongue and jaw?

Whether you or a kid or an adult, when you learn something new you often do funny things with your face. 

Even at rest a lot of us hold tension in our face. 

Commonly the tongue and jaw can tense up.  You might feel tension in the throat. 

Tension in these places can also relate to tension in the neck. 

Relaxing the tongue and jaw are key to helping you relax your parasympathetic nervous system (physiological relaxation) but can also help physical relaxation of the muscles around the head and neck. 

In class, I will often cue people to relax the tongue and jaw or relax the face.  I am known for pulling funny faces to remind you of this. It really helps.

How are the mats aligned in the room in the class?

It might sound benign but the first thing I ask people to do in class is to align their mat so they are looking towards me with their whole spine when standing at the top of the mat.

If your mat is aligned to the front wall of the class and not the teacher you will necessarily have to twist your neck in an awkward position to see them even when you are standing straight. 

These days I rarely practice with a mat as I find that you can tend to prioritise aligning yourself on your mat rather than aligning yourself to yourself.  I have found that students naturally align their spines better when they don’t have this mat anxiety, although I appreciate that some people really like them and don’t mean to suggest you shouldn’t use one or that they are not useful.

And then…

Applying cues for head and neck position, cues about shoulder and arm position and armpit activation, cues to relax jaw and tongue, and reminders about aligning your spine to the teacher (or mat position if you use one) can really help to prevent neck tension when teaching/practicing.

It is likely you will find you need to keep giving these cues to yourself/your class as you practice, as it can be easy to forget, especially if you have habitual patterns of tension.

As a teacher teaching a large class it can be difficult to address each student’s unique needs.  I find these cues are helpful for everybody irrespective of whether they have a pre-existing neck condition.  As a student you need to remind yourself to approach your teacher if things do not feel right, as they will always seek to give helpful advice and feedback. 

I am always mindful that our bodies are all different on different days and that sometimes cues that work for most of the population might not work for you in particular.  You need to pay constant attention to what is going on and if a particular instruction or cue does not feel right then do not use it.  I would always recommend asking your teacher about it as they will have given it for a reason and it could be that you are not quite doing what they asked or it is, indeed genuinely the wrong cue for you. 

I know this particular student had come from an Iyengar style class and that this approach is very therapeutic.  With these cues in mind I think she would be able to participate in those classes and just make appropriate modifications that suit her needs.  But it might also be that a flowing style is more conducive to her overall goals and needs at this particular time.  There are so many styles of yoga and even within particular styles the teacher will have their own slant.  I think the sorts of cues I have written about here can go beyond a style though and I hope that, having them on board, you can participate in whatever class is right for you!

I really recommend the online courses by Simon and Bianca to further your learning and approach to practice.   Happy and safe practicing!

Is it wrong to take your shoulders towards your ears in when taking arms overhead?

Me in natarajasana where I need to move my armpits forwards and upwards so I don't squash my back.  [photo from Canberra Yoga Space].

Is it wrong to take your shoulders upwards as though to your ears? 

Do you know you have muscles put on your body to do precisely that?  Has your body been designed incorrectly?

It is not wrong to take your shoulders upwards towards your ears.  Ordinary life requires it, especially when reaching overheard. 

Go find a shelf that is beyond your reach and try to reach for something that is on it.  Barring any shoulder/neck issues you will no doubt automatically take your shoulder forward and upward.  If you looked to the side you could probably smell your armpit it is so high.

If you have young kids then take them to a playground and watch them swing and hang from bars.  You will see that when they hang their shoulders are right up beside their ears (and they will probably bring their knees to their chest with ease, something that most adults cannot do!). 

The movement of shoulders towards ears is a natural movement that will happen in overhead reaching, often with a little side bend if you are doing it one-armed.

So I have to ask myself why am I being told in some yoga classes I attend to take my shoulders away from my ears when they are overhead?

[And I have to ask myself why did I sometimes say this to students when I was a new teacher?  Certainly not because my senior teachers had ever told me to.]

Here are some reasons I have come up with.

·      People think that a lot of us already have tension around the upper shoulders and next and hold our shoulders in a little shrug so as a yoga teacher we should tell them to counter this by keeping them down away from the ears.

·      People think it squashes the neck to take the shoulders to the ears in overhead movements.

·      People want to strengthen muscles around the shoulder blades, especially when they give the instruction to pull the shoulder blades down and together. 

There could be other reasons as well and it would be great to hear from people about this.

Here is why I am not comfortable with those three reasons as being sufficient explanation or justification for teachers to give the instruction to move the shoulders away from the ears in overhead reaching. 

Overhead reaching includes poses like adho mukha svanasana (downward dog), adho mukha vrksasana (handstand), urdhva hasta tadasana (standing with arms overhead), utkatasana (fierce or chair pose), urdhva dhanurasana (back arch from the floor), and virabadhrasana 1 (warrior 1).  There are many more, including most of the advanced backbends where you reach and catch a toe behind your head, as well as inversions like pincha mayurasana and headstand.

First, it is true that many of us hold subconscious tension around the upper shoulders and hold them in a little shrug.  But we generally hold them in a little shrug, not a big one, and the shoulder never gets the chance to go all the way up.  It is important to encourage people to take their joints through their full natural range of movement.

Also, sometimes people who hold persistent slightly shrugged shoulders might not be aware they are doing so.  Sometimes activating the muscles with consciousness and taking them all the way up can alert them can help them become aware of this and learn to notice when there is slight tension and then learn to try to relax.

Importantly, as I discuss later, if they are going to take their arms overhead for advanced postures they need to take learn to move their shoulders towards their ears when it is required or they will squash their spine.

Second, it is true that it can squash the neck if you take your arms overhead and lift shoulders to ears.  However, that is often because people are trying to take their arms overhead and then behind their ears or level with their ears.  Most western people are way too stiff to be able to do this correctly. 

Instead, if you take the arms overhead and push the armpits forward and up you should find any neck squashing tendencies are countered. 

Allow people to keep their arms in front of their ears and encourage them to push their armpits in the direction they are facing. 

If anyone still feels any neck squashing then you could instruct them to take the arms lower so they are in front of the face (but still pushing armpits forward). 

Third, I believe this is probably an instruction that is not helpful in yoga with overhead reaching positions.  The reason is I have seen it given mostly in positions where the spine is upright and also extended (going towards a backbend). 

In a backbend you want to use your arms to help you create length in the spine, not compression. 

The instruction to move the shoulders down and together will create compression in the spine.

The instruction to move the armpits and shoulders up and forwards will create length in the spine. 

To tell people to bring the shoulders down in poses like utktasana or virabadhrasana 1, where the lower back is already more likely to be squashed (though with careful practice it will not be), will place most people at risk of further squashing their spines. 

It is not until you start to move into more advanced postures that you realize the real importance of being able to take shoulders up and forwards.  Drop-backs, backbends from the floor and advanced backbends that involve reaching arms overhead to hold onto a foot that is also circling behind and up (like a full natarajasana or kapotasana) all require you to take the armpits towards the ears. 

Ask any practitioner who is in those poses to do otherwise and they will instinctively tell you no way as it will shorten the back body, which they are trying to lengthen. 

My view is that we are trying to help people free their spines, not squash them.  So let’s give them instructions that will help them in that regard.  While you may not be teaching your students these advanced backbends, poses like vira 1 and utktasana are preparatory poses for those positions and if you do not give appropriate instructions in those poses they will never get to the more advanced versions.

If you want to help them build strength around the shoulder blades through actions of drawing them back and down there are other postures more suitable.

These include poses that require interlacing behind the back, or the floor backbends that do not involve taking the arms overhead such as up dog or the simple forms of dhanurasana where you hold the ankles (but not the full dhanurasana which has you take the arm forward and overhead to reach the toe), or simple bridge poses with arms interlaced behind the back. 

It might be a more useful cue for your students to watch they do not flare their lower ribs forward as they take their arms overhead. Stiff people will often use spinal extension to get their arms fully overhead by pushing the ribs forward to compensate for lack of movement in the shoulders.  This can again squash the lower back and it is perhaps more useful for them to not take the arms so high so the spine is not masking the work. 

I want to finish by being clear that I am talking about taking shoulders to ears in overhead reaching positions.  Also, I want to be clear that I do not think it is wrong to take shoulders away from the ears (depression).  That is also a natural movement of the body. 

However, I wanted to inspire some thought about considering the consequences of what you instruct and whether your instruction is contradicting another instruction you are giving, or whether you really mean to be giving that instruction for that particular pose.  I see this frequently when teachers tell me to lengthen my spine in vira 1 and then come and tell me to pull my shoulders down and back. 

For me, the best instruction to give is to tell people to activate their armpits when taking the arms overhead so the armpits press in the direction they are facing.  In an overhead position this is forward and upward.  I learned this from Simon and Bianca at Yoga Synergy.  

This simple instruction can be applied to positions where the arms are not overhead, such as plank, where again you can just instruct people to push the armpits in the direction they are facing (in that case down towards the floor and towards the hips).  If I take my arms behind my back I can press my armpits down and towards one another.  You can learn more about this and other tips to enhance your yoga practice via the Yoga Synergy online anatomy course. 

While about to post this, I also found another article that explains some of these ideas from an anatomical perspective written by Dr Roger Cole.  You can link to it here.

Also, last year I also wrote a post about taking the shoulders away from the ears!  There, I focussed on addressing the tension that gives some of us chronic tension and causes that habitual half-shrug look about us in our day to day life (I rather, perhaps unthinkingly called it rugby neck, mainly based on the look of the shrugging shoulders not necessarily what is happening at the shoulders).  My aim was to get people to use some tricks outside of yoga (e.g., at their desks) to catch that creep, or to provide them with a useful tool to counteract the tension.  However, in that post I clearly stated there are occasions where you want or need to take them up--especially in overhead positions.  I promised to write more on that but it has taken me time.  This article is the article I should have written a while ago on that matter!

5 Minute Sequence To Release Neck & Shoulder Tension

I wanted to post a serious video.  A few seconds into recording my 2 year old niece walked in.  I think the video is much better with her in it.  You can watch me or you can watch her running around having fun.  She doesn't need to be told how to release her neck and shoulders as she spends her time running around and playing and we can all learn a lot from such unencumbered movement and joy.

For those of us who have become a bit gnarly with age, see if you can watch and listen to my instructions and move your shoulders and neck in freedom.

Remember, never force, tense less, stretch less, and move slowly.  If it does not feel good then it is not good.  Talk to me in class, by email, or otherwise discuss with your teacher if you need clarification.

Shoulder/Shoulder Blade Movements
This sequence gets us to move our shoulders and shoulder blades in four general directions (there are some other things going on but I won't complicate things).

High Shoulders
I ask us to move the shoulders up high.  To the ears if possible.  Some people are scared of this movement, believing their shoulders are already a bit high.  However, while most of us probably do hold our shoulders a little high and tense this is generally subconsciously.  That is, they are tensed without us realising it.  We rarely bring them up through the full range of movement.

The ability to move the shoulders up high is essential for some other yoga postures where the arms are raised overhead (e.g., warrior 1, handstand).

Being able to bring the shoulders up high also helps to traction (lengthen your spine), especially when combined with softening the sitting bones down.

Taking the shoulders high and holding for a time also gets us to move them through the full range of movement.  If you release the shoulders down after holding them high for a little time you will often find they relax down more.

Armpits down
I also ask us to move the armpits down towards the waist. Moving the armpits towards the waist firms the inner and outer armpit muscles.

It also causes the muscles on top of the shoulders to relax through a spinal reflex known as reciprocal inhibition.  This basically means that when I firm a particular set of muscles, the muscles that cause the opposite movement to occur will relax.  If you hold tension on top of your shoulders then this is a great little trick to do a few times a day.  Just don't overdo it. Do not firm to your full capacity.  Be relaxed and calm.

Shoulder blades forward
Pressing the shoulder blades forward helps strengthen muscles on the front and sides of the chest.  When held for a few breaths this can also cause relaxation of the muscles that squeeze the shoulder blades together.

Moving the shoulder blades forward also naturally causes the upper spine to bend forward.  Over the years I have found that a lot of people spend a good deal of time being too straight--with shoulders pulled back and chest puffed up.  If you ever get pain between the shoulders blades or tired between the shoulder blades after sitting for some time then moving the shoulder blades forward like this can help relieve the fatigue and/or tension.

I find that I need to be particularly mindful of head and neck position when I press my shoulder blades forward or I get a little tense around the throat.

Shoulder blades drawn back
Drawing the shoulder blades back is something most of us are familiar with.  Some people will find this really difficult if they habitually slump or have their shoulders rounded, however.

At a particular point in the sequence I bring my shoulder blades back, then I press my armpits down.  From there I interlace my hands behind my back as this is comfortable for me to do.  It might not be comfortable for you so you do not need to interlace the hands and you can just keep the shoulder blades back and down.  Remember do not force this action.  Do not force any action.

Holding the shoulder blades back together will cause the muscles that draw them forward to relax a little.

Head/Neck Movements
This sequence also has some combined head/neck movements.  Make these movements small.  So small it feels like your head is floating.  Do not move the head as much as it can move.  Be cautious and alert to any disturbing sensations.  Correct practice can help your neck problems (I have them myself--you might notice how asymmetrical my head is atop my shoulders) but incorrect practice can aggravate.

Throat lightly forward, chin lightly up
At certain points in the practice I do what looks like taking my head up or looking up.  However, this is two movements.  The first movement is me pushing my throat lightly forward.  The second movement is me taking my chin lightly up.

When performed correctly it should feel like the front of the neck is lengthening without squashing the back.

Chin to the middle of the throat
I also direct us to bring the chin to the middle of the throat.  That action is also two movements.  Here, the throat moves lightly backward and the chin moves down towards the middle of the throat.

When performed correctly it should feel like the back of the neck is lengthened without squashing the front.

Chin to the shoulder, ear tipped away
At certain times in the practice the head is facing in a different direction to the centre of the chest.  If this is the case, then I tip the chin in towards the shoulder that my head is closest to and I tip my ear away from that shoulder.  I do this in twisting and side bending.

When performed correctly it should feel like both sides of the neck is lengthened.


I pop on a good song and do this type of practice throughout the day, especially if I have been sitting down for a long time.  It helps bring circulation into the shoulders, upper back, and neck area as well as improving overall mobility.

Bhujangasana Tips and Common Errors

Aiyo! Spot the issues

I want to start by getting you to take a look at the picture to the left.  This very flexible person has taken themselves into Bhujangasana, cobra pose.  We practice this pose a lot in my classes.  I chose this particular photo of it because it highlights some of the concerns I commonly raise  with my students.  Can you spot the issues I would raise about the way this guy is holding the pose?  Hint: there are five main ones.


Hands
Let's start with one of the main weight bearing points: his hands (the other is the legs but I will leave those aside for now).

Look closely at how he holds them on the floor.  It is hard to tell but I am pretty sure all of the weight is bearing down through his wrists because I cannot see his fingers spreading at all.

Your hands are like your feet.  They have natural arches in them.  You must cultivate those arches in the hands so that you generate lift.  If you do not, you will sink into the wrists and they will become painful and you won't be able to hold the pose for very long.  To help generate this lift and take away from the wrists you need to press very strongly down through the mounds of the fingers (the base of the knuckles).  Spread wide from the base of the index finger to the base of the baby finger and extend out through your fingers.  As you do this, see if you can suck up the middle of your palm from the floor almost as though you were trying to lift the floor up.  This takes quite a bit of work at first but you will find the pressure on the wrist reduces dramatically.  If you find you seem to be stuck in your wrists and they are hurting then you can always put a little bit of height under the wrists (fold up the end of your yoga mat) which will help you take the weight off the wrists.

Elbows
Moving up from there let's take a look at the elbows.  Elbow joints come in all forms.  This guy has what I would call really bendy elbow joints. People with bendy elbow joints often think their elbows are straight when in fact they are hyper-extended or over-straightening as I like to say.  The picture below shows a similar issue but from a different angle.

Locked elbows (pose needs improvement)

You can see the inside part of the elbows have spun around to point forwards (you can also see the same hand issue here with the fingers together and weight through the wrists).  What has happened here is that the elbows have locked into position so that the arms are effectively held straight by holding in the elbow joint rather than using the muscles.  Locking the elbow joints when you practice any pose where the arm is weight-bearing (like this one or downward dog or handstand) can lead to injuries in the wrist, elbow or shoulder joints so you want to avoid it.  From what I have seen on the mat, a tendency to lock in the elbow joints is often related to weakness in the biceps or triceps muscles (which are responsible for bending and straightening the elbow joint) so that if you enter a pose which requires those muscles to work with the arm in a straightened position your body chooses the easy way out locks the joint rather than use the muscles.

The problem for many people who tend to lock the elbow joints like this is that the arm 'feels' straight when they lock them.   And what often happens is when I come around in class to put the elbow in the correct position people with this issue will say the elbow now 'feels' bent.   Your body has internal sensors that give you an idea about the position of your joint without having to look at it (which is why we can walk without having to look at our feet).  In this case, the way these people have learned to interpret the sensations from the joint has lead to them mislabeling what is actually straight and what feels straight.  To compensate for this you need to look carefully at the elbows when you are in weight-bearing positions of the arm to check with your eyes rather than rely on the internal sensors.  The inner elbows should end up pointing rather more in towards one another rather than pointing to the front.

In bhujangasana the elbows don't have to be straight.  They can actually be bent.  How much they bend depends on how you do the pose.  There are many ways to do this pose and some people keep their elbows very bent and don't come off the floor all the way.  If you are going to straighten your arms you need to make sure you are not straining in your lower back and most of us will probably find that if we straighten our arms we will need to let the pelvis and maybe even the upper thighs come off the floor.  The photos below show some better elbow positions for this posture.

Elbows slightly bent (good, working with his capacity). 

The photos above shows a man with his elbows ever so slightly bent.  That is fine because he is working to his capacity.  His shoulders are down away from their ears (we will talk about the shoulders next).  His chest is open and expanding--just like a cobra spreading his hood.

Shoulders
If you don't use your hands and elbows properly, it is likely you will end up with your shoulders like the boy in the first photo--shrugged up around your ears.  Aside from making you look like a vulture or buzzard with no neck, this is not good for the shoulder joints.  Some people do use their hands and elbows well but still end up with their shoulders as ear-rings, although the three are often connected. 

Shrugged shoulders (pose needs improvement)

   
The photo above shows the hands are not working well (you can see the base of the knuckles are lifted off the ground rather than pressing), the inner elbows are pointing more to the front, and that she seems to be hanging in her shoulders.   She has pushed her chin up to give the illusion of a neck but this is just the front of her neck that is long--the sides of the neck are scrunched down into the shoulders. 

Now, look at the two photos below.  In the top one you can see the shoulder shrugging more clearly.  See how the tops of her shoulders seem to be pushing up and the chest is sagging below the shoulders?  It is almost as though her body is hanging down from the high point of her shoulders.  Contrast this with the shoulders in the bottom photo.  See how there is more space between the top of the shoulders and the ears? 

Shoulders pushing up and chest is sagging (pose needs improvement)

Chest is rising (good)

In bhujangasana the chest needs to rise up between the shoulders and expand outwards to give rise to the posture's namesake: the cobra.  To get this flare of the cobra's hood you need to use your hands and arms effectively but also draw your shoulder blades down your spine.  The image below showing this woman from the front clearly shows the expanding and lifting (as opposed to closed and drooping) chest.

Expanding and lifting chest (good)

Neck 
There are so many variations for the neck in this posture--as you can see from all of the photos above.  I tend to feel that unless you know how to take your neck back properly (if you are wondering what properly is then that is a clue) then you are better off just keeping your gaze directed forward.  Otherwise, you will just scrunch the back of your neck and that is never good.  

Take a look at the picture below of the guy in our first photo at the top of the page.  By now you will will notice the hand and shoulder shrugging problems previously mentioned and the hyper-extended elbows.  Now, look at the spine as a whole and notice the curvature.  Also, draw and imaginary line running from between his shoulder blades to the base of his skull.  What do you notice?

What can you notice about the angle of the neck relative to the rest of the spine?

What you will see is that all of the curve of the spine is coming first from the lower back (he is really flexible there) and from his neck.  In between he is pretty straight.  This is not the way to treat your spine if you want it to remain healthy.

The way I teach bhujangasana (which is not the only way) is to try and have students go for a more even distribution of the curvature of the spine from the bottom to the top.  This means trying to let the curve at the neck follow the curve of the rest of the spine.  You get a better idea of why when you take a look at the full expression of the pose below:

Full cobra with more even distribution of curvature of spine

In the full version of this posture the feet and head touch.  This pose might not be a place where a lot of us will ever get to (and who cares if we never do it anyway?  Will your life be so different?) mainly because it requires a lot of flexibility.  But, if you are working towards it what you need to do is emphasize more lift and open-ness through the thoracic spine (upper back) otherwise you will get scrunching in the lower back and neck.  Many very flexible people who lack the strength to hold this posture correctly may find themselves able to get into the position but experience discomfort in the lower back in particularly if they are not generating the appropriate lift and expansion of the chest.  But more about that in a second.

The neck is a very flexible structure that most of us hold tension in.  In my classes I see a lot of people automatically flopping their heads back when they come into this pose.  I always wonder why because I never teach people to take their heads back and I never do it myself.  If you are doing it and it feels good and there is no tension anywhere along your spine then by all means continue--I am not Uncle Scrooge and don't want to take away a nice feeling!  But if you are doing it because you have seen a picture of someone doing this pose before and their head is back then have a rethink about what you are doing.  If you are doing it because you think you should be doing it then also have a rethink.

Head and neck placement should always be very mindfully considered.  Here is what I would recommend.  If the centre of your breastbone (sternum) is pointing straight ahead then you should look straight ahead too.  Only if the top of your chest can start to turn up to the sky should you consider taking your head back.  If you are going to take it back make sure the curve in the neck follows the curve that is present in the middle of your upper back between the shoulder blades and try and feel that the distribution of the curve in your spine is even.  And remember, taking your head back is actually more about taking it up than backwards.  You need to feel your head lifting off your spine.  I am not going to go into detail here (might leave it for another post) and for the mean-time make sure you have a chat to your teacher if you are not sure about what to do with your head.  The safest thing to do if you have any doubt is to keep looking straight ahead!

Lower back
Finally, we get to the lower back or the lumbar spine.  The flexibility you have in this part of your spine  and across the front of the pelvis and thigh will ultimately determine how you come into this posture.   The main point to consider is that should have not pain or scrunching feeling in your lower back when you do this (or any) posture.

When I look at the guy in our first picture I get the impression he is extremely flexible in his lower back.  You can see there is an almost 90 degree angle between the pelvis and the rest of his spine.  Most of us will not get that sort of curve.  I can't help but feel if he continued to practice this pose as he is he will end up with lower back issues if they are not present already.  It is hard to tell but it seems to me he is locking into his elbows and collapsing into his wrists and shoulders in order to push himself into bending in the lower back to be in this posture rather than using his muscles to support himself there.

In bhujangasana the muscles along the spine need to work to hold us in place, rather than just collapsing into the most flexible parts (lower back and neck).  Nearly everyone I have ever seen in class with a very flexible lower back finds this pose difficult--not coming into it, which they can all do with ease--but holding it because they invariably tell me their back hurts.  This is usually because they are flexible in their spines but not strong.  And this is where the difficulty lies because this pose is as much about strength as it is about flexibility.  The muscles of the spine needs to be strong to bring your torso up against gravity, the muscles of the abdomen need to be strong to prevent collapsing into the lower back, the muscles around the shoulder blade need to be strong to open the chest and prevent you from collapsing into your shoulders, the muscles of the upper arms need to be strong to hold them straight, the muscles of the forearms and hands need to be strong so you don't collapse into your wrists.  This pose is about lifting, expanding and curling your body back onto itself and you will not get these things without using your muscles appropriately.

As I keep saying, there are so many variations of this posture so bear this in mind.  Some people like to practice keeping the pubic bone on the floor and with the arms bent.  Some practice with the arms in front of the shoulders.  Some practice with the arms below the shoulders.  Some allow the pubic bone to come off the floor and straighten their arms.  Some are able to keep the pubic bone on the floor and straighten their arms at the same time.  How you practice will depend on your yoga teacher's style and your own strength and flexibility.  Changing the position of the hands and elbows and deciding whether or not to allow the pubic bone to come off the floor are decisions you can make about your own practice, always bearing in mind that any of these adaptations should be made to maintain or promote freedom in your lower back.

Let's take a look at the photos below, which show adjustments of the hand, elbow, and pubic bone position that will give your cobra a different look and feel.  Each of these poses shows an accommodation for the flexibility in the lower back and across the front of the thigh and pelvis.

Fig 1: thigh bones lifted off the floor

Fig 2: hands moved in front of the shoulders

Fig 3: hands under shoulders and thigh bones on the floor

Fig 4: hands under shoulders, elbows very bent and pelvis on the floor 

Fig 5: hands under shoulders, elbows a little bent and pelvis on the floor

Each of these people is basically working within the limits of their lumbar spine coming into this posture.  Let's go through the figures one by one.  

In Figure 1 the person has straightened her arms fully.  However, because there is not enough flexion in her lower back she has done the right thing, which is to let the pelvis and top of the thighs come off the floor.  The main thing you need to remember if you are doing cobra this way is to make sure you do not  sag into your belly.  You need to keep the belly in very strongly or you end up 'hanging' in your lower back (having said this, all variations of cobra require you to draw in your abdominals--you will just feel the consequences of not doing so more strongly in this variation).  Always come back to the feeling you are having in your lower back and if you feel compression or scrunching then you can try to draw back through the belly and soften the lower ribs back to your spine and if these two don't work, bend the elbows and let the pelvis and thighs come back to the floor. This is the way we usually do the posture in my class (which doesn't make it right but is just the way I teach), and most people will have their pelvis off the floor.  

In Figure 2 the person has kept her pelvis on the floor but taken the hands out in front of the body.  In my classes we don't usually do this--not because it is incorrect but because we come up with the hands behind the shoulders.  If this person tried to bring her hands back under her shoulders she would probably find she would need to let the pelvis and thighs come off the floor like in figure 1.

In Figure 3 you can see the lady has hands under shoulders and elbows straight and pelvis on the floor, reflecting a very flexible lower back and flexibility across the front of the thigh and pelvis.  Most people would find this very difficult but some do not and you just need to make sure there is no scrunching in the lower back.  If there is, accommodate by going for the position in figure 1 or 2.

In Figure 4 the lady has decided to stay in a very low cobra and really use the muscles of her spine.  We  do this position often in my class (but without the hands on the floor) just before we take the hands to the floor and come up to finish with straight elbows (taking our pubic bones away from the floor as required).  This is a really good way to strengthen the muscles of the back and shoulder blades that help you hold this posture in the final version with ease.  You will likely feel the muscles of the lower back working the hardest here but see if you can get more even work throughout the spine so that you can feel work in the upper back as well.

In Figure 5 the lady has bent elbows and the pelvis on the floor.  She is still working the muscles along her spine really strongly and this is a good position to work in to combine strength and flexibility.  If you do not have the flexibility in the lower back the only way to come further up is to push with the arms and let the pelvis and thighs come off the floor, which is fine.  You will end up like the lady in Figure 1.  

Summary

I hope this post has been helpful in giving you some insight in the common errors I see in bhujangasana.  You need to carefully consider how you are using and positioning your hands, elbows, shoulders (and shoulder blades), neck, and lower back.  Remember all yoga postures are about lifting not sinking.  You need to generate lift out of all of these parts of your body or you will collapse somewhere else, which will lead to pain and possibly injury over time.  

The whole of your body is working in bhujangasana.  I did not mention the legs but the legs and feet need to be pressing into the floor, the abdominals lift to support your lower back, the muscles along the spine are working to lift you out of your pelvis and generate an even curve, the muscles of the shoulder blades are working to draw them down away from your ears and towards the centre of your spine to expand the chest, the muscles of the upper arms are working to hold the arms in place and prevent buckling into the wrists or pushing into the shoulders, the muscles of the forearm and hands are working to prevent collapse into the wrists.  Remember to carefully position your neck so that the curve is distributed evenly along your spine.  Go to your yoga teacher for guidance.  

As you practice, see whether or not you are falling into any of these common errors.  Look at yourself in a mirror if you can. Always ask yourself whether you are feeling freedom or compression, particularly in the wrists, elbows, shoulders, neck and lower back.  If the answer is compression then do something to change that.  If the answer is freedom, well done!

Happy and safe practicing.