In my last post What is Range of Motion (ROM) we discussed ROM and how it is measured. It is something that is interesting to note, as we often assume in Yoga that all joints can move in all directions and degrees in all bodies. I have often heard one “should” get to blah blah in a certain pose. Have you ever considered the length of limbs, torso-to-limb ratio, height, weight, age etc. and how that might impact a pose, and everyones ability to be in a shape.

That would be akin to saying all women wear the same dress size. And I don’t know about you, but I certainly know that I am Not the same size as a Sports Illustrated or Victoria’s Secret model. Or many of the yoginis I teach!

We often say that Yoga is individuated, and yet also say that we “should All be able to have 90 degree arms in chattaranga” , be able to bind our arms around leg/torso in all bound poses, and other myths. As I have continued my own study of anatomy (under the guidance and tutelage of Judith Hanson Lasater, who is a physical therapist and senior yoga teacher), I have discovered my own truths about myself and others. Additionally, I have grown older, had injuries, illnesses and other aspects of life that have changed my view on asana.

Types of Joints
There are 360 joints in the human body, and joint pain is defined as pain, stiffness, or swelling in or around a joint. There are several types of joints in the human body.

Ball and Socket Joints – a wide range of rotation and movement. The shoulder and hip are ball and socket joints.
Condyloid Joints – movement but no rotation. There are condyloid joints in the jaw and fingers.
Gliding Joints – bones glide past each other. There are gliding joints in the ankles, wrists and spine.
Hinge Joints – movement like a door hinge. The knee and ulna part of the elbow are hinge joints.
Pivot Joints – allow bones to spin and twist around other bones. There are pivot joints in the neck and the radius part of the elbow.
Saddle Joints – back and forth and side to side motion but limited rotation. There is a saddle joint in the thumb.

So, after hunting around the web, I have found some medical standards for “average and normal” ROM (Range of Motion) in major joints of the human body. Here it is, and it may surprise you!

The Jaw
HINGE MOTION – open at least one inch, closed to proper occlusion.
Retrusion – 1/16 inch, protrusion – 1/4 inch. Rotation through a vertical or transverse axis – 1/4 inch from midline.

The Neck

NEUTRAL POSITION – Head Up and Chin In.
Forward bending (flexion) – 50 to 60°
Backward bending (extension) – 45 to 55°
Lateral bending, right and left – 30 to 40°
Rotation, right and left – 50 to 60°
When we nod the head in “Yes” we seesaw the skull on atlas joint, in a rocking motion. If the head is rotated from side to side in “No”, it is turned on the pivot joint between the atlas and axis, as a rotating platform.

The Spine

NEUTRAL POSITION – Spine in Perpendicular Position.
Forward bending (flexion) – 70 to 90°
Backward bending (extension) – 20 to 30°
Lateral bending, to right and left – 25 to 35°
Rotation, with pelvis fixed, right and left – comparing angle made by shoulders with pelvis – 30 to 40°
Motion in spine is hard to evaluate because the cervical and lumbar regions are freely movable, while thoracic spine is limited. Forward bending is extremely variable, and depends upon general physique, exercise, laxity or contracture of muscles, etc.

The Shoulder

NEUTRAL POSITION – arm at side with humerus in lateral plane of body and elbow extended. Since arm is pointing to 6 o’clock on a circle, the starting point is one of 180°.
Abduction, with elbow flexed 90° (glenohumeral motion) – arc 180 – 90°
Adduction, with elbow flexed 35 to 45° (glenohumeral motion) – arc 180 – 145 to 135°
Abduction with scapula fixed elbow extended 90° (glenohumeral motion) – arc 180 – 90°
Abduction, with scapula free elbow extended 180° (shoulder girdle motion) – arc 180°
Forward elevation (flexion), with scapula fixed 90° (glenohumeral motion) – arc 180 to 90°
Forward elevation (flexion), with scapula free 180° (shoulder girdle motion) – arc 180°
Backward elevation (extension) 45 to 55° (glenohumeral motion) – arc 180 – 135 to 125°
Adduction with elbow extended 35 to 45° – arc 180 – 145 to 135°
External and internal rotation, with arm in abduction – arc of 180°
External rotation, with arm at side and elbow flexed 35 to 45° – arc 180 – 145 to 135°
Internal rotation, with arm at side and elbow flexed 70 to 90° – arc of 180 – 110 to 90°
Circumduction – 360° (shoulder girdle motion)

The Elbow

NEUTRAL POSITION – forearm in extension
Extension to 180°
Flexion to 45° – arc 180 to 135°
The carrying angle of the elbow is the angle at the long axis of the humerus and the long axis of the forearm. The average is about 15º.

NEUTRAL POSITION – elbow flexed at 90° and forearm midway between pronation and supination (forearm at the vertical)
Supination, with wrist, from vertical – 90°
Pronation, with wrist, from vertical – 90°
Supination, without wrist, from vertical – 85°
Pronation, without wrist, from vertical – 50°
The radius may be the main bone of forearm and wrist, just above distal end of the radius, and on inner side of the bone, there is an articular surface – sigmoid cavity. This is for articulation with distal end of ulna. The distal portion of ulna also has a lateral articular facet. This joint permits radius to rotate around ulna through an arc of about 140º, hand and fibrocartilage moving with radius.

The Wrist

NEUTRAL POSITION – Hand in line with forearm with palm facing downward
Radial flexion – 25 – 35°; arc 180 to 155 – 145°
Ulnar flexion – 35 – 45°; arc 180 to 145 – 135°
Dorsiflexion (extension) – 55 – 65°; arc 180 to 125 – 115°
Palmar flexion (flexion) – 60 – 70°; arc 180 to 120 – 110°
Abduction and adduction of wrist occur almost entirely at radio-carpal joint. Flexion and extension are largely at this joint. The position of strength in the hand is one of moderate dorsiflexion. As the angle of dorsiflexion is lost, the flexion power of the fingers is diminished.

The Thumb

NEUTRAL POSITION – thumb alongside forefinger and extended.
Extension to straight position – 180°

Abduction (metacarpophalangeal joint) – 50 – 60°
Adduction (metacarpophalangeal joint) – 20 – 25°
Proximal joint (metacarpophalangeal joint) – 30 – 35° – arc 180 – 150 to 145°
Distal Joint (interphalangeal joint) – 70 – 90° – arc 180 – 110 to 90°
Abduction – 50 to 60° – arc 180 – 130° to 120°
The trapezium-metacarpal joint is part of the wrist, but its motions are, within limits, independent of the wrist. Abduction of thumb is measured by taking the distance from proximal joint of index finger to tip of thumb in abduction and comparing it with opposite side. One main function of the hand is grasping power between thumb and fingers. Loss of motion, particularly in  thumb, is extremely important.

The Finger

NEUTRAL POSITION – fingers in extension
Extension – 180°
Proximal joints – 80 to 90°; arc 180 – 100 to 90°
Middle joints – 90 to 100°; arc 180 – 90 to 80°
Distal joints – 45 to 60°; arc 180 – 135 to 120°
In the fingers, the metacarpophalangeal joint plays an important role. Limitation of motion affects the entire finger in normal closure of hand.