The objective of this study is to examine the influence of body position and additional axial load on spinal stiffness in young healthy adults.

Spinal stiffness plays an important role in the assessment of the spine in the clinical daily routine. It is often performed as a manual PA-pressure test in the prone position. The spinal stiffness is the result of the resistance from the active, passive and neurological subsystems, like muscles (active), ligaments, joint capsule and the skin (passive). Further research had shown, that the spinal stiffness depends also from other factors. It is increased by axial compression. A better understanding of spinal stiffness leads to novel insights into spinal stabilization mechanisms.

Inclusion Criteria:

• healthy

Exclusion Criteria:

• Acute backpain (thoracal or lumbar)
• History of significant backpain (thoracal or lumbar) or radiating pain down the leg
• Contraindications to PA mobilisation/manipulation
• Spinal fractures
• Spinal tumors
• Surgical intervention in the thoracic and lumbar spine
• Local infections of the spine or the surrounding tissue

Young healthy adults