This document discusses the biomechanics of yoga asanas. It begins by defining biomechanics as the study of structure, function and motion of biological systems. It then covers the key components involved in biomechanics - bones, joints, muscles, ligaments, tendons and nerves. The rest of the document analyzes the biomechanics of different parts of the body like the vertebral column, hips, knees, ankles and shoulders and how they function in specific yoga poses. It emphasizes applying mechanical principles to understand joint movements and muscle actions to perform asanas correctly and prevent injuries.

1. Biomechanics of Yoga
Presentedby:
YogaLife AsanasandMeditation

2. • Biomechanics involves:
• study of the structure, function, and motion of the mechanical aspects of biologicalsystems.
• study of the effects of internal and external forces on the human body is called
biomechanics.
• Mechanical principles applied to the study of biological functions is called biomechanics.
• Bones, Joints, Muscles, Ligaments, Tendons, Nerves etc. play equally important role in
biomechanics of human body.
• The application of mechanical laws to human body while practicing yoga posture is called
biomechanics ofYoga.
Introduction

3. Different types of joint

4. Joint Movements

5. Muscle
• There are about 640 muscles in human body.
• There are three types of muscle tissue: cardiac, smooth, and skeletal.
• Skeletal muscles are attached to bones, allowing body to move.
• Joints move because skeletal muscles contract and move them.
• Skeletal muscle is responsible for the movement of joints in asana.

6. GroupAction of Muscles
Agonists: Group of muscles which contract to provide the force required to produce the
movement.
Antagonists: These muscles oppose the action of agonists and relax progressively for
permitting the movement.
Synergists: These groups of muscles work with agonists to provide a suitable activity and
facilitates the movements
Fixators: These muscles stabilize the bones of origin of the agonists and increases their
efficiency for production of movement.

7. Bones, Joints,Muscles,Ligaments, Tendons,Nerves etc.work togetherto produce
movement in humanbody.

8. AnatomicalDirectionsand Planes

9. Movement on Frontalplane Movement on Sagittalplane Movement on Transverseplane

10. Stretching
Cyclic stretching: A relatively short-duration stretch force that is repeatedlybut
gradually applied, released, and then reapplied
Ballistic stretching: A rapid, forceful intermittentstretch,that is, a high speed and
high intensity stretch
Mechanical stretching: Using equipment to stretchand increase joint ROM.
Manual stretching: External force applied by therapist to move the involved body
segment slightly beyond the point of tissue resistance andavailable ROM.
Neuromuscular inhibition techniques: these proceduces reflexively relax tension in
shortened muscles prior to or duringstretching.

11. Postures
Posture is the attitude assumed by the body
Postures may be either Active or Inactive
There are basically three categories of postures in Yoga
• Cultural: for physical fitness, specially by stimulating and relaxing different groups of muscle
• Relaxing: for relaxation, specially before and after cultural postures
• Meditative: for meditation (mental fitness), generally sitting and stable
Culturalposture Meditativeposture Relaxingposture

12. Muscularpositions in YogaPostures
Ekapada Rajakapotasana

13. Biomechanics ofMuscles
All movements are shaped by force ofgravity.
In Padahastasana:
• Hamstrings, gluteus muscles and erector spinae are extensors of hip joint not flexors.
• They act to create flexion of hip by letting go with gravity to control downward
movement.
• It’s lengthening contraction of hip extensors and erectors
In Virabharadrasana II:
• Partially bent but stabilized knee
• The antagonist must release at the same rate that the agonist contracts.

14. Padahastasana VirabhadrasanaII

15. Biomechanics of VertebralColumn
• Biomechanics call it a kinetic chain (connected chain of moving parts).
• It is designed for both movement and stability.
• Stability is created by tripod stool in each vertebra (Intervertebral disc and two facet
joints).
• In vertical pose like Tadasana and siting in Siddhasana, maintaining the natural curve
will create most stability.
• Range of movement of each vertebral segment is determined by intervertebraldiscs.
• Direction of movement is determined by angle of facetjoints.

16. Tadasana
Siddhasana

17. Biomechanics of CervicalColumn
• Joints between skull and C1 allows only flexion and extension (Yes Joint)
• C1-C2 joint allows flexion, extension, & rotation (NoJoint)
• 50% of rotation on cervical spine comes from C1-C2 joint.
• Apex of extension is at C4 and apex of flexion is atC5
• Rolling head and neck around in a circle is a non-anatomical movement.
• The cervical joints are not ball and socket joints like the shoulderjoints.

19. Biomechanics of Thoracic Spine & Rib Cage
Over-flattening of natural kyphosis (sometimes,happens because of the practice of
wrong posture)
• Practitioner lift sternum with the intention of opening the chest
• After years of practice, the spine loses some of its natural curve
Side bending and rotation occur to the opposite side except the movement are
begun in flexion.
• In Trikonasanaperformed to right, the thoracic spine & cage rotate to left (toward ceiling)
• In ParivrttaTrikonasana,if you rotate first before flexing, the natural side bending will be to
opposite side.
• Bending forward first then rotate to Parivrttatrikonasanais under the law of movement of
thoracic spine.

20. ParivrttaTrikonasana
Trikonasana

21. Biomechanics of LumbarSpine
• Significant movements allowed in this region are flexion and extension.
• 50% of all the movements of flexion allowed in entire vertebral column is created in lumbar
spine.
• Out of that, 75% created in L5-S1 joint.
• Abdominal muscles and organs are highly responsible for the limitation of extension in lumbar
spine.
• The facets in this region allow for almost complete free range of extension.
• Rotation of the lumber spine is quite limited (10 degrees).
• It may seem like you are rotating from lumber spine in Ardha Matsyendrasana, but it’s not true.
• Here too, side bending and rotation occur to the opposite side (as in Trikonasana).

22. Ardha Matsyendrasana

23. Biomechanics ofSacrum
• Primary function of sacroiliac join is stability.
• Some passive joint movements occur here.
• When you bend your lumber spine back (as in Ustrasana), sacrumpassively
moves anteriorly.
• When you bend forward (as in Padahastasana), sacrum movesposteriorly.
• These coordinated movements are called lumbo-sacralrhythm.

24. Padahastasana Ustrasana

25. Biomechanics of HipJoint
• The gluteus maximus is a hipextensor.
• The gluteus maximus has a secondary action of external rotation as well.
• It extends the hip joint and externally rotates it at the sametime.
• In back bending poses like Dhanurasana & Chakrasana, feet and knees goesout
instead of being straightahead.
• By pressing the knees toward each other, you can activate adductormuscles.
• This neutralizes the external rotation component of the gluteus maximus

26. Dhanurasana
Chakrasana

27. Biomechanics of Knee Joint and Legs
• One of the misconception about the knee joint is that it acts as a hinge.
• Instead, the knee moves with a rolling and gliding action during flexion and extension.
• During extension, the femur rolls backward on, while tibia glides forward on femur.
• During flexion, the femur rolls forward, while tibia glides backward.
• During flexion, femur rotates slightly externally on the tibia (its healthy unlocking
mechanism).
• The rotation happens at front knee joint in Parsvakonasana, Virabhadrasana I &
Virabhadrasana II

28. VirabhadrasanaI

29. Biomechanics of Ankle and Foot
• In Normal ankle joint, there is approximately 45 degrees of planter flexion.
• Dorsiflexion is limited to approximately 20 degrees.
• Dorsiflexion is also limited by tightness in Achilles tendon, gastrocnemius andsoleus
muscles.
• The supination movement of ankle is quite free and can be overdone in poses like
Padmasana.
• Extreme supination easily can lead to sprain of lateral collateral ligaments of ankle.
• Pronation is much less free than supination in ankle joint.
• Eversion of the foot often accompanies pronation of the ankle.

30. Padmasana

31. Biomechanics of shoulderjoint
• Biceps muscle is elbow flexor and also a shoulder flexor.
• The strongest action performed by biceps is supination of forearm.
• Biceps action will be easier in Viparitakarani as biceps will have mechanical advantage
(supination of forearm).
• Most significant aspect of movement in shoulder joint is the glenohumeral rhythm.
• The gleno-humeral rhythm involves scapula, humerus & clavicle.
• The gleno-humeral rhythm accompanies shoulder flexion and abduction while
performing yoga postures.

32. Viparitakarani

33. Biomechanics of Elbow Joint and Forearm
• Common positional faults of elbow joint in yoga asana practice is hyperextension of elbow.
• The condition refers the relationship between humerus and ulna on extension of the joint.
• Hyperextension occurs when elbow is extended past the angle of 180 degrees.
• Another positional fault at elbow joint is called carrying angle, more common in women.
• When elbows are inside the straight line during full extension with supination, carrying
angle is present.
• Increased carrying angle contributes to the instability of elbow joint.
• Over stretch on elbow joint should be avoided while practicing asana.

34. hyperextensionof elbow
carrying angle

35. Biomechanicsof Wrist and Hand
• Under normal circumstances,the wrist and hand are not weight bearing
structure.
• But in asana practice, they sometimes bear weight in poses like Chaturanga
Dandasana.
• By strengtheningforearm muscles & by paying attention to alignment, they can
be kept healthy.
• One should pay attention to the placement ofhands on floor in weight bearing.
• One should be careful in the poses like Bakasana andmayurasana.

36. Bakasana

37. Knowledge of biomechanics is essential to perform postures correctly & to avoid injuries.
Thank You