YOGA STUDIES with Paul and Suzee Grilley

Bone Photos

These images show the normal variation in human bones. None of them are pathological. They graphically display why no two people will ever do yoga poses the same way. If peoples' bones are different then their joints will have different ranges of motion.

Please feel free to download and use these images for educational presentations and lectures. Click on each image you want and a larger file of that image will come up for you to download.

Hip Socket

Photo of left hip socket of two pelvises

Left hip socket of two pelvises. The socket of the left specimen is pointed forward and down. The socket of the right specimen pointed sideways and nearly horizontal.

Photo of two hip sockets pointing in different directions

Hip sockets pointing in different directions. Therefore the range of motion in different directions will be different.

Photo of two hip sockets

Hip sockets on right hand specimen are not visible from this front view because they are oriented out to the sides rather than forward.


Photo of six left femurs

Six left femurs. Oriented upside down in this image to make it easier to show torsion in the next two images.

Photo looking down on six left femurs

Looking down on the neck/head of six left femurs. The degree of torsion (twist) increases from left to right.

Photo looking down on two extremes of femoral torsion

Two extremes of femoral torsion. Looking down on the neck/head of two left femurs. Feet parallel requires completely different femoral rotations.

Photo of two left femurs

Two left Femurs. The inclination of the neck is 40° different. The ability to abduct would be 40° different.

Photo of two left femurs from the front

Two left femurs in front view. Specimen on the left has a neck that is twice as long.


Photo of two right tibia

Two right tibia. The specimen on the left has external torsion. "Feet Parallel" would require an internal rotation of the tibia or femur.


Photo of two right humerus bones

Looking down two right humerus bones. Specimen on left is torsioned internally. Therefore the humerus would have to externally rotate to place "hands parallel".


Photo of two right scapula from the back view

Two right scapula from the back view. The acromion process on the left specimen doesn't cover the shoulder socket. Humerus abduction would vary tremendously.

Photo of two right scapula

Two right scapula. Left specimen could easily clasp hands behind the back. The acromion of the right specimen would block this movement.

Photo of three right shoulder sockets of the scapula

Three right shoulder sockets of the scapula. The vertical axis of each is different. The acromion processes are also different.

Photo of the ventral view of two right scapula

Ventral view of two right scapula. Coracoid process on the right specimen is slanted downward, more likely to pinch with humerus in chaturanga.

Photo of two left scapula

Two left scapula. Acromion on left specimen doesn't cover shoulder socket, making it easy to raise arms past vertical.

Lumbar Vertebrae

Photo of lumbar vertebrae

Lumbar vertebrae. The gaps between spinous processes are different, so their back bending extensions would be different.


Photo of three sacrum

Three sacrum. Originally five bones fused in the womb. Different ratios of length to width due to the shape of bones.

Photo of two sacrum

Two sacrum. Originally five bones that fuse in the womb. Difference in curve due to difference in the five bones.