Lotus Pose might be physically impossible for that student no matter how much they practise. The femur on the left might make it reasonably easy for that student to sit in Lotus Pose while the femur on the right might make it really difficult for that student to even sit crossed-legged. The image below on the left, courtesy of Paul Grilley, beautifully demonstrates this huge variation in the position of the head of the femur relative to the shaft of the femur between individuals. The AV angle will inevitably impact the range of movement of the hip joint in flexion, extension and rotation.

The mean left/right difference in AV was 3.8°. Bråten et al (1992) found significant variation amongst the group in their study and stated that the mean AV angle was 18° in the women and 14° in the men.

The femoral neck in the average person is also rotated slightly anteriorly and this is referred to as femoral anteversion (AV). Relating this natural variation to yoga, the femoral neck-shaft angle will impact the degree to which one can move one’s leg directly out to the side (abduction) in a pose like Wide Leg Forward Fold (Prasarita Padottanasana). Anderson and Trinkaus (1998) stated that mean values range from 122° to 136°, and normal individuals are found from around 110° to almost 150°.

There are no universally accepted normal or abnormal angles. Femoral neck-shaft angles (in blue in the image above) show considerable variation within human populations.

Lotus position