MODUL 4
What are we commonly doing with the spine in modern life?
Prolonged sitting is a significant risk to the spine – it exaggerates the rounding of the spine and the muscles and other soft tissues weaken.
Repetitive flexion and rotation postures and movements are also a risk in modern life in several occupations.
Also to note is the tendency toward a head-forward syndrome particularly with the proliferation of digital devices.
Functional anatomy
The curves of the spine
Side view (sagittal plane): double-S-shape due to kyphosis and lordosis.
Physiological curvatures of the spine are different in every individual!
Changes with development from infancy.
Affected by use and posture, age, genetics, injury.
Intervertebral disc
The intervertebral disc consists of cartilage. Because cartilage does not have blood circulation it is nurtured by diffusion from the vertebral end plates. It depends on cycles of loading and unloading for nourishment to flow into it and waste products to be cleared out of it.
The disc is not just cartilage though – it is a specialized structure that has rings of fibers on the outside (annulus fibrosus) and a gel like consistency (nucleus pulposus) inside. Due to this specialized arrangement, it is capable of resisting forces in all directions.
A further detail is the criss-cross architecture of the outer fibers. The result? Rotation leads to increased tension in one half of the fibers and decreased tension in the other half. This renders the disc less resistant to bulging in some regions. This is why some movements like loaded flexion plus rotation place the disc in danger of damage. In fact, that is the most common mode of injury to the disc – repeatedly loading the disc in these vulnerable positions over time.
Strong ligaments stabilize in the front and the back of the discs, so the disc can bulge in a diagonal direction most easily – this is why it tends to compress the nerves on one side of the spine, particularly in the low back, resulting in the characteristic pattern of sciatica or pain running down the leg.
In the context of yoga, note that the pressure inside the disc is greatest in the morning – so be careful of forward bends and rotations in the morning practice.
Concept of neutral spine
The middle position where the curves of the spine are not too much or too little – neither in excessive kyphosis or excessive lordosis.
The action of lengthening upward, being tall, is termed axial extension – it feels as if the spine is extended along its long axis.
Neutral spine / axial extension incorporates a smooth lordosis of the lumbar spine, comfortable extension of the lower thoracic spine, a tall cervical spine, and aligning the head with the neck.
Extending or lifting from the lower thoracic spine is the key to the neutral spine. The lumbar spine position is related to the pelvic tilt. Comfortable engagement of the lower abdominal muscles as well as the spine extensors is required to support the neutral spine position.
To improve posture, it often is useful to start with the thoracic extension component. This is mostly more important in all standing postures and movements. Seated positions often require to reposition the pelvic region – mostly towards anterior pelvic tilt to reestablish the physiological lordosis along with the gentle lift of the thoracic spine.
“Neutral Spine” is not a fixed position but a range of motion in the middle – it’s not required that it be a perfect point, you have to discover that middle range where the spine is stable, strong, and tall. This position also allows for deeper and better breathing (increased ROM for the chest, diaphragm, abdomen), better cardiovascular functions (amongst others increased movement of the heart along with the breath), enhanced digestive functioning and alters one’s emotions/feelings as well as the expression (as one is being perceived).
Loading the spine
Like all other tissues in the body, the spine needs loading to be healthy and resilient. The safest position for loading is a neutral spine where the forces are distributed most evenly among the structures of the spine – the disc and vertebral bodies in front, the joints at the back, and the supporting soft tissues like ligaments surrounding these.
In particular, the neutral spine makes it easier for the spine muscles to stay active. Active muscles are profoundly protective of the other structures in the spine – it converts shear forces to compressive forces, which the spine can tolerate much better.
Low back (lumbar spine)
Functional Anatomy
Different parts of the spine move differently. The anatomy of the lumbar spine allows flexion (forward bending) and extension (backward bending) most easily. Rotation is limited in the lumbar spine.
The lumbar spine is closely attached to the pelvis, so the tilt of the pelvis is reflected in the lumbar spine. With an anterior pelvic tilt, the lumbar spine moves into extension and with a posterior pelvic tilt the lumbar spine moves into flexion.
Shear forces are greatest in the lumbar spine. It is at the base of a long, loaded column, rather like the base of a fishing rod. Hence the disc and other non-contractile soft tissues such as ligaments are at maximum risk of damage in the lumbar segment of the spine.
Repetitive forward bending especially in combination with rotation, lifting wrongly and slumping in a seated posture are major culprits that cause problems in the lumbar spine tissues.
Muscles surrounding the lumbar spine
The spine extensors run in long columns along the lumbar spine to the back, to either side. They are part of the longer chain extending up the spine – functionally they cannot be separated from the extensors of the thoracic spine. These muscles are key to lifting and lengthening the spine into a tall posture. Contraction of one side of these muscles leads to side/lateral bending. All three layers of abdominal muscles do have part of their origin within the lumbar fascia. This is the biggest fascial sheath of the human body covering and interfusion all three layers of back muscles.
Deeper, numerous small muscles (multifidi, rotatores) span the smaller segments of the spine from one vertebra to the next one, two, or three vertebrae. These muscles generate smaller movements, especially rotation and also help to sense the position of each vertebra clearly. They stabilize and participate in any asymmetric movement or hold.
The abdominal muscles wrap around the lumbar region, from the ribs above to the pelvic bone below. Inserting into the fascia surrounding the lumbar spine they are crucial in maintaining stability in the lumbar region. They are also most important to generate a full exhalation.
The diaphragm and pelvic floor form the internal support of the spine, providing inner pressure changes with the breath that naturally stabilize and mobilize the spine from within. A simple truth is, that due to their origin and insertions, inhalation which is the contraction of the abdominal diaphragm helps towards spinal extension and deep exhalation facilitates and enhances spinal flexion.
Spine joints, ligaments, and other soft tissues
Viewing the spine from the back, you may observe that each vertebra connects to the one above it through joints on either side. Every rib also connects with the vertebrae and the processus transversi of the thoracic spine through joints.
The columnar stack of vertebra constituting the spine requires stabilization. That is provided by muscles and also by many ligaments – long ligaments running through most of the length of the spine and shorter ones spanning just a few vertebrae.
Ligaments also serve critical sensory functions. The tension on ligaments informs the nervous system of the position of the vertebra and the load on them.
Pain Free
Suggested positions in order to make someone feel comfortable and safe. Make sure, you find a good position to start with. Breathing should be possible in an easy way.
- Supine with knees bent or roll under the knees
- Lying prone or on one side
Sometimes clients may even feel much more at ease in hands-and-knee pose rather than standing, sitting or lying down. Do not be afraid to actually let people try out different positions from where a practice could be started.
Alignment – Axial Extension or “Neutral Spine”
For the lumbar spine the safest alignment is in the middle position. Gentle curves of the spine established usually leads to a smooth, long lordosis in both seated and standing positions that extends well into the thoracic spine. To establish that or even find the neutral position you may try to:
- Standing – hands on chest and abdomen
- Standing – one hand spanning navel to sternum
- Standing – hands on head
- Seated – someone’s hands on the shoulders
If this is felt by you or your student and one is able to stay, walk with or even bent a little forward while maintaining the gentle lordosis you may proceed with establishing neutral spine position in:
- Rising from seated on a chair
- Kneeling
- all-fours pose
- all-fours with raising the knees off the mat
- Plank or side plank
- Bridge
- Lying to seated with a relatively neutral spine
After that, the last and equally important step is to put on additional weight and add movement tasks while maintaining the spine close to its optimal position. One may try variations in lifting:
- Something from standing
- Lunging forward / reaching / turning
Stabilization
In order to stabilize the lumbar spine, a concerted action of all muscles involved is needed. To prevent injury or to recover from locomotor system problems alignment is of the essence in both movement and stay. This is especially important also in daily life, as we will see later on. To keep the spine stable meaning to restrict movement as close to the neutral spine position and within the pain-free ROM.
Muscles involved in restoring and maintaining a good posture are the back muscles including the quadratus lumborum and iliopsoas, but also the abdominal muscles (all four of them) as well as the abdominal and pelvic diaphragm. Again, the differentiation of muscles or muscle groups is somewhat artificial and due to didactical purposes as all the muscles mentioned above actually work together in an orchestrated way in order to help stabilizing the trunk in an upright position. Additionally and selv evidently, also the muscles of the adjacent regions of the thoracic spine (front, sides and back), the muscles around the shoulder blades and the muscles stabilizing the pelvic bones with the lower limbs are essential in restoring or maintaining stabilization of the lumbar region within complex movements in sports and daily life. The above mentioned technical term of cocontraction is especially important for the center of our body. The lumbar spine and the region of the lower abdomen and pelvis are exposed to huge leverage. Whatever movement we do on the yoga mat and in daily life, the center should be stable in order to allow the limbs to do movements without us losing either balance or alignment. That said, you might understand, why it is so essential to move from a stable core. Not doing so – also in yoga – often leads to a huge variety of trouble and injury.
Strength, Endurance
Asana one might choose in order to work on the strength or/and endurance of the:
- Spine extensors:
- One third chair with neutral spine
- Variations of one-third chair with different arm loads
- Gentle forward folds from chair pose, straightening up to strengthen e.g. hugging to round the spine and flying with arms open as spine straightens.
- Hug + fly + rotation
- Bridge
- All fours arm and leg raises with lots of variations.
- Cobra variations (note: to create strength in the low back it is not enough to work on the muscles of the low back alone. Backup is needed from the spine extensors further up! And like always: try along with different breath patterns supporting either stability or flexibility)
- Engaging movement or hold in warrior I and warrior III towards neutral spine or extension from hip flexion or even the lumbar spine flexion are asymmetric by nature and require strength not only in the region of the glutes but also strengthen the erector trunci muscles.
- Abdominal muscle
- Plank variations
- Side plank variations (note: these do not simply strengthen the abdominal muscles. Of course, there are all muscles involved that help to stabilize the pelvis-thigh conjunction as well as the erector trunki on the lower side of the spine)
- Active variations of knees-to-chest pose and no-floor touch twists (in fitness often called crunches)
- Leg lift (one side, both sides) best performed while maintaining gentle low back lordosis. Variations of the head position and if done with one leg also of the position of the leg which remains on the ground
- Diaphragm and pelvic floor muscles
- Stay in all gentle to complete inversions will strengthen the abdominal diaphragm as for example staying in bridge, forearm-knee pose, half shoulder stand, down dog, dolphin, head- or handstand
- Package post (lying supine, embracing your legs with your forearms and lifting your head towards your knees gives access to cultivating and experiencing pelvic floor movements and thereby enabling students to exert more activation is usually a good starting point.
- Conscious engagement is often the method of choice if one is not habitually using the pelvic floor muscles in complex movements on the mat and in daily activities. If you carry things or lift from the floor usually these muscles are involved. A lot of life events, trauma, giving birth and patterns learned amongst others may prevent one from engaging the pelvic floor muscles. If so, we have to mention the activation by wording in different asana in order to facilitate reintegration. Also with deep exhalation, prolonged as well as fast exhalation techniques usually the engagement of the pelvic floor muscles happens without further need of facilitation. But that has to be communicated or trained with the person or being a topic of discussion in a group class situation. Some people within the field of yoga consider mula bandha as being the contraction of the pelvic floor. If agreed upon this terminology, it becomes easier to make sure the students get what you want them to do without using more words. If the contraction of these muscles does give justice to the terminology is a matter of consideration.
Mobilization and Traction
Mobilization of the lumbar spine can best be done in either lying supine, prone or on all-fours-
- Supine legs straight
- Heel push
- Hip kick
- Supine legs bent in the knee joint, feet on the ground
- Grass in the wind
- Hip kick
- Lying twist variations with one leg straight
- Prone
- Pelvic shake
- All-fours (hands or forearms on the ground)
- Cat-cow movement
- Milk tread
- Concrete mixer
- Lying eight with the trunk
- Wailing dog tail (one leg or both legs)
- Funny crawling
Traction in the region of the lumbar spine is best done in:
- Hanging both upside down or hands on a bar.
- Note, that also the fast and small movements mentioned above under mobilization do exert traction on the facet joints and somewhat on the intervertebral discs.
- Assists – sometimes used in the field of yoga or in one-to-one situations can exert gentle traction e.g. pulling the calf while lying supine with the knees bend, pulling both legs lying supine or even more common pulling the pelvic area while student in down dog.
Flexibility, ROM and Stretching
Most of the asana commonly done promote a fair amount of flexibility. Individual adaptation is extremely important, otherwise damage may be done over time.
Flexibility can be increased along with the help of gravity, against gravity (more strength required) or lying down. The more load is put on the lumbar spine, the better one’s strength should be and the more important alignment becomes. Using gravity to facilitate the ROM is perhaps the most dangerous way to increase the ROM and needs careful awareness in order to not exceed one’s limits.
- Lying down:
- Pelvic rolling
- Lying twist
- Standing legs parallel
- Standing legs spread or in front of each other
Coordination and Speed
Detoxification
In both, everyday life whether the private part or professionally and on the yoga mat sometimes detoxification does the job. The greatest impact on a body region happen with things we do a lot. For a lot of people that is sitting. All tissues of the lumbar spine are exposed to loading, movements and of course many other influences such as nourishment, thoughts and other habit patterns. The way one sits and the duration of each sitting period, the way one stands up from a chair or lifts things from the ground affect not only the bony structures, but also the lumbar discs and the forces they have to counteract, the facet joint and their nourishment situation as well as the nerves and connective tissues in this area undergo either beneficial stimuli or are exposed to wear and tear. Possibilities to easily enhance the wellbeing of this region are positive changes in your ADL. One might try to improve:
- Sitting position as well as trying breaks or microbreaks in between
- Sitting up or down
- Lifting from the floor
- Kitchen related tasks
- Household related tasks
- Carrying (things / bags / backpacks)
- Daily routines often can be altered significantly to the better as one reevaluates habits as in how to get to work, where to park the car, how to use the breaks, possible times to rest or to incorporate useful and healthy movements in ones daily or weekly routines as walking, crawling, hanging, sports and of course nourishment habits.
Disorders of the Lumbar Spine
Missing: Spondylosithesis, Lumbar disc herniation, Osteoporosis, some words on scoliosis, low back pain
Sacroiliac Junction
What is the sacroiliac region meant to do?
All forces such as weight of the trunk, head and upper limbs are transmitted via the sacroiliac junction towards our hip joints and further down towards our feet. Gravity puts a lot of load on this area and as it is close to the center of our body, the lever of the movements we do with our limbs is huge. Evolutionary development has put a lot of challenges to this region, as upright walking had to be considered. Movements of our trunk and limbs have to be conducted without endangering the stability that is needed to do so. Both, the spine and the hip joint are much more flexible and put a lot of leverage on this junction which essentially is made to be stable and has a huge surface which fits congruently into each other. Indeed, the construction of the joint is such that it does not even need so much directly covering muscles. As you will see later, the opposite is true for the hip joint and the adjacent spine. On the other hand, the SI-Joint region had to allow for giving birth to human babies which have relatively huge diameters meaning, under delivery this region had to be somewhat more lose at least in women.
What are we commonly doing with the sacroiliac region in modern life?
Nowadays, most people engage into a sedentary lifestyle with more or less movements in between. The level of activity that would strengthen or challenge the sacroiliac junction – or ligaments, fascia, muscles and the joint structure itself – is limited apart from times of sports or when being on the yoga mat. As this is done in a balanced way, hardly any problems in this region arises. The opposite is true for people who engage in intensives ways of practicing yoga, dancing, gymnastics or onesides load bearing activities. If challenged, the hip joint is built so strongly that it will withstand a lot of activities easily, but the same does not count for the SI-Joint. Whenever the ROM of the spine or the hip joint is exceeded, the forces are delivered through the SJ-Joint. Repetitive strain may be put on this region with limited possibilities to adapt.
Functional anatomy of the sacroiliac region
The sacrum and coccyx bone are built like a triangle fused into each other without any intervertebral disc in between. The junction between the sacrum and the two pelvic bones on either side is called the SI-Joint. It is nicely congruent providing enough stability to transmit the forces from the spine towards the hip joints and vice versa. The stability is such, that even without muscles directly covering the joint region, everyday activities and even prolonged periods of sitting or sports usually do not harm the joint. A tight joint capsule and ligaments cover the relatively huge joint surface (compared to the facet joints) and provide only little movement possibilities. The 1-2 millimeters of movement the joint is capable of in relation to the adjacent pelvic bones is called nutation and counter nutation. It is done in the sagittal plane (anterior/posterior). For all other directions the joint is pretty much fixed due to the nice fit of the joint surfaces.
To keep these joint surfaces firmly connected, the hip bone can be pressed towards the sacrum. This can easily be done by abduction and external rotation in the hip joint, so that gravity and the weight of the thigh put more load on the SJ-Joint.
Problems arise usually when the movement capabilities of the spine or the hip joints are exceeded and thereby forcing the SI-Joint into movement. Especially for torque, torsion or asymmetric forces as done in splits, deep lunge, asymmetric forward bends (pigeon pose, one-leg flexed forward bend like janu sirsasana), triangle with and without twists as well as seated twists and many others) the SI-Joint has little to ability to counteract. Over time, the joint gets more flexible which otherwise only occurs in late pregnancy to allow for delivery. More flexibility is a common source of discomfort or even pain in this region. And please note, that for some people, the poses mentioned above are no problem at all due to the anatomic/genetic flexibility and accompanying strength, whereas for others, these positions lead towards chronic pain experiences even when from outside, the SI-Joint appears in perfect alignment. If done in the end ROM abilities, the outside appearance does not reflect upon the forces applied on joint level.
Pain-free
In the area of the sacrum and the SI-Joint this goal appears a little tricky as pain usually does not arise in the very situation. Not even after one or several times of stressing the area pain usually is a problem. With some awareness, discomfort could be noticed, but usually ambition takes over when reaching towards somewhat more demanding positions and in everyday life sitting in a stooped and asymmetric position (half cross-legged, lazy sofa position or putting one leg upon the other) does not lead to pain. Only when lifting a little to much on top of not being in good shape or – in the context of yoga – pushing a little too often and too much seemingly suddenly brings up the feeling of pain. So our suggestion is on one hand being extremely careful with asymmetric legg positions and using gravity to increase ones range of motion and on the other hand, to reduce the amount of repetitions in order to prevent repetitive strain (injury) on the mat and in ADL (e.g. lifting, sitting, carrying,…). This requires a lot of the other skills we will discuss further down such as awareness and strength/endurance to maintain stability.
Pain in the SI-Joint region arises due to instability, not with stiffness
Awareness & Exploration
Keep an eye on the region!
Knowing the anatomy, even looking up the pictures and functional context at the skeleton or in a book is worth a try in order to make sure one is not suddenly facing harm or pain. During movements in everyday life and on the mat or while doing whatever sports activity one does, it is useful to connect with this area of concern. Mild discomfort or the sensation of comfortable pain should be questioned. Being clear about the adjacent regions as the lumbar spine and the hip joint coming to their individual end range of movement abilities and thereafter straining the SJ-Joint is helpful to prevent going to deep into asymmetric forward bends and combined rotation as these are the movements of concern.
Stress Management and Relaxation
In a broader sense applying heating oil, external warmth and gentle massage may help locally to relax the region. Apart from that, the understanding of the functional anatomy and the necessity for stabilization may also add to relaxation of the mind, as one might feel empowered on which steps to take to reach towards healing or in preventing damage.