Sirsasana (headstand) technique alters head/neck loading : considerations for safety
MetadataShow full item record
Headstand, the king of all yoga poses, requires practitioners to support the full body with the forearms and crown of the head. A goal of novice and expert practitioners alike, sirsasana performance technique significantly modifies head and neck loads. This study examined the weight-bearing responsibility of the head and neck (separate from the arms) at moments of peak force during entry, stability, and exit of three typical performance methods. The three methods were: symmetrical extended leg (SE), symmetrical flexed leg (SF), and asymmetrical flexed leg (AF). Three groups of 15 participants each (2 males, 13 females) were formed, each group performing one technique. All 45 subjects (18-60 years of age) reported an active yoga practice including sirsasana with no record of cervical injury. After a 10 min warm up, participants performed three headstands. Kinematic and kinetic Vicon data were analyzed to locate peak forces acting on the head, loading rate of those forces, center of pressure, and neck angle at C3 in the frontal plane. Force plate data revealed flexed leg techniques produced the greatest forces during entry and nominal forces on exit. The SE condition produced lower forces on entry as well as slower loading rates during stability. In the frontal plane, neck angle about C3 tended towards neutral, or natural cervical lordosis, in SE and flexion in SF and AF during entry. COP showed no significant differences between groups; however, lateral movement at the apex of the head was markedly larger than movement in the sagittal plane for all techniques. Previous research has shown flexed loading, rapid loading and larger loads can increase potential damage to the cervical spine especially in women and aging individuals. As that population is heavily represented in yoga studios, the data support the conclusion that modifying headstand technique may reduce some of the mechanical risks of headstand.