If you have read my last four articles in this series on Injury Prevention you’ll know how passionate I am about the anatomy of the human body. I am a firm believer that knowing how the body moves through space and how exploring and supporting these movements with our breath and bandha activation encourages a long, active and vibrant life both on and off the yoga mat. You’ll find the links to the previous articles at the bottom of this article.
In this article I will take a deeper look at the importance of joint integration, more specifically the subject matters of gravity, joint reaction forces, the “inelastic-ness” of ligaments and the importance of not hanging on our joints in poses such as Downward Facing Dog, Chaturanga Dandasana and standing poses such as Natarajasana (Dancer’s Pose).
How well do you know your joints?
How we approach strengthening (joint integration during weight/load bearing) and stretching (dynamic rotations and static stretching of soft tissue in and around the joints) will depend on these six inquiries:
1. Joint construction: is it a two bone or three bone joint?
2. Joint type: Is it ball-and-socket (hips/shoulders), hinge(elbows/knees), compressive (vertebral column/talus-calcaneus), ellipsoid (wrists), or saddle (thumbs)?
3. Primary function: little to no movement (fibrous, sutures of skull); weight bearing/compressive joints (cartilaginous vertebral column) or movement/leverage (synovial joints like hips, knee, shoulders and elbows)?
4. Orientation: higher or lower center of gravity (in anatomical position)?
5. Mobile or stable?
6. What type of soft connective tissue supports it: thick and dense or thin and strappy?
We can compare and contrast the shoulder and hip joints to illustrate joint similarities and differences. For detailed diagrams of the skeletal and muscular systems take a look at InnerBody.com
Shoulder Joint
1. Construction: Three Bone Joint (humerus, clavicle and scapula)
2. Joint Type: Ball-N-Socket (flexion, extension, abduction, adduction, internal and external rotation)
3. Leverage (reach and pull)
4. Higher center of gravity (attaches to axial skeleton at sternal-clavicular joint)
5. Mobile (spacious and shallow joint)
6. Thin and strappy supportive tissue (like fettuccine!)
Read more about shoulder anatomy in For the love of the shoulder
Hip Joint
1. Construction: Two bone joint (femur and Ilium)
2. Ball-N-Socket (flexion, extension, abduction, adduction, internal and external rotation)
3. Leverage (movement on this earth i.e. walking, running, biking, lifting form seated)
4. Lower center of gravity (attaches to axial skeleton via thick bones of ilium and strong gluteus maximus and ellipsis muscles)
5. Stable (one bone into one socket)
6. Connective tissue: Thick and dense
As you can see, both the shoulder joint and the hip joint have Leverage as their primary function. Due to the lower center of gravity of the hip girdle it is a given that the hip joint and extremities will incur a lot of weight bearing (simply by standing not to mention running, jumping and other higher impact activities). The thick fibrous ligaments and the strong, multilayered muscles of the hip and buttock support this.
It is important to mention that the knee, even though a lower center of gravity than the hips, has strappy and thin ligaments (thicker than in the shoulder girdle but definitely nowhere as thick and dense as the ligaments found in the hip).
With this appreciation for the design of the knee and the “inelastic-ness” of ligaments, yogis, especially hyper extenders like myself, should take care to not “hang out” on the back of the knee in standing poses such as Natarajasana. Especially in classes that specifically instruct you to “lock your knee”. It is more conducive to the health of the knee (cruciate ligaments as well as hamstring and adductor tendons) to activate the necessary quadriceps muscles to provide support and stability – this is joint integration!
By pressing down through the four corners of the standing foot and extending the knee by engaging the quadriceps muscles (lifting the kneecap) you effectively put into practice the concept of joint reaction forces (gravity pulling us down and the force we apply to defy this downward pull).
Remember: every action has an equal and opposite reaction. Are you doing your part in effectively executing the opposite reaction to gravity?
The shoulder girdle, for most of us, is rarely asked to take upon itself the weight of the body. For many aging adults shoulder/weight bearing happens rarely: pressing on armrests to help propel oneself out of a chair, leaning on an arm for the required push to get out of bed, and/or sometimes lifting something overhead to put on a high shelf. That is why we often come to the yoga mat to encourage more mobility in our hips and more strength and stability in our shoulders. Those of us practicing challenging styles of yoga such as Ashtanga Yoga, Power Yoga and other forms of dynamic Vinyasa Flow find ourselves in many upper body weight bearing postures.
The same rules apply here as in the knee: just because you have the range of motion in certain joints to hyper-extend (akin to “hanging out”) doesn’t mean it is good for the ligaments of that joint, especially in weight bearing postures, for you to do so.
Joint Integration
“Just because you can hang out on your joints doesn’t mean you should!”
Here are some common examples where “hanging out” can happen and how to use joint integration to prevent injuries:
Shoulders in Chaturanga Dandasana:
If you are hanging out on the ligaments between the clavicle (collarbone) and acromion process (roof of the scapula/ shoulder blade) and also on the ligaments inside the shoulder girdle itself, the chest and ribs will be noticeably lower than shoulders and shoulders will be dipped far below the elbows.
Instead it is important to find the proper “L” shape through bone alignment, muscle activation and joint integration:
- Bone alignment: head of humerus (upper arm bone) in line with the elbow, elbow on top of wrists and ribs never breaking the plane of the humerus bones.
- Muscle activation: healthy pectoral activation, balance between biceps/triceps, lower trapezius, latissimus dorsi, infraspinatus and serratus anterior.
- Joint integration: using these muscles to effectively and efficiently support the humerus bone in socket.
Elbows in Chaturanga Dandasana:
If your Chaturanga Dandasana is too low you will be applying too much weight/load bearing on elbow ligaments. Instead find the “L” shape described above for elbow health as well as shoulder health. Also…NO JUMPING BACK TO HIGH PLANK…the repetitive shifting of the humerus above the ulna and radius over time will result in laxativity in your elbow ligaments!
Shoulders in Downward Facing Dog:
For those that have the range of motion to bring the chest through the shoulders in Downward Facing Dog remember, although it may feel good to stretch so deep, it is a weight bearing pose on your ligaments. And ligaments, once overstretched, will never go back to their original state.
To support the joint integration of the shoulder girdle, engage infraspinatus and serratus anterior to wrap shoulder blades (adduct) towards outer ribs and externally rotate upper arm bones in their sockets.
Elbows in Downward Facing Dog:
For those that can hyperextend their elbows it is important to not turn the eyes of the elbows towards front of mat but instead keep a micro-bend at the elbow with bicep strength in Downward Facing Dog (plank and side plank too).
Connective tissue and individual differences
elastic: material that can return to its original state after being contracted, stretched or distorted.
All connective tissue in the body, from our bones to our skin, is a matrix mixture of collagen, elastin and ground substance.
Collagen is an inelastic protein that when abundant makes the connective tissue more dense.
Elastin is a protein capable of returning to its original shape once distorted, and
Ground substance is amorphous material supporting the homeostasis of other cells and fibers.
Even though there is a general consensus that some connective tissue has more elastin than collagen (muscles and tendons) and others more collagen than elastin (ligaments, cartilage and bones) it is important to note that the proportions of elastin and collagen can differ from body to body. Some people are naturally more “bendy” than others and are able to maintain great joint stability even while wrapping their long limbs around their other long limbs. Their ligaments have a little bit more elastin than someone else who is so solid, sturdy and compact that to put them in a similar posture would mean utter and complete destruction to the ligaments connecting their bones. Always check in with the strength (stability) and suppleness (mobility) of your connective tissues and joints – it is not wise to sacrifice one for the other. This is a case of both/and, not a case of either/or.
Yogis: Superheroes Defying Gravity
Gravity wants to pull us down – it is what gravity does. What we can superficially see as the effects of gravity (our skin succumbing to its downward pull) is happening deep on the inside as well (fluids, internal organs, and connective tissue being drawn downward). Yogis, among other physical and mental benefits, seek to reverse the ravages of time by defying gravity (turning upside down and floating through air). My five step process for longevity – breath, bandhas, bone alignment, muscle activation and joint integration – all play an important part in this intention.
Where once you may not have been able to hold your own body weight up in a Side Plank, Full Wheel, or Handstand with the practice of yoga you now do effortlessly. Where once you may not have had the strength to perform one perfect Chaturanga you can now safely float your way in and out of 25 of them with ease and grace. Where once the thought of floating from a Handstand to a Chaturanga or landing in a Full Wheel variation from a Forearm Balance made you gasp and shake your head now, with a consistent practice of the step-by-step process of yoga AND the practical application of breath, bandhas, bone alignment, muscle activation and joint integration, you think, “I too can do this; the possibilities are endless”.
One of my favorite sentences from the Bone Alignment article in this series is “At the bone level we are essentially an axis with a bunch of levers and fulcrums…both a mathematician’s and an engineer’s dream!”. The first step for caring for the fulcrum and levers (joints of our body) is knowledge. Then it is of the utmost importance that we embody these facts and theories with our consistent diligent practice of body-mind connection practices such as Hatha and Vinyasa Yoga. And remember: just because we can hang on our joints doesn’t mean we should!
x Jennilee
Read all the articles in Jennilee’s 5-step series on preventing yoga injuries:
