Individuals with smaller joints and thinner spines may have greater spinal mobility but less capacity to sustain vertical compression.

“now at the opposite extreme you're going to have people with smaller RIS smaller ankles smaller knees and they in general are going to have a thinner spine meaning vertebrae and discs that are smaller in circumference and they are not going to have the capacity to sustain as much vertical compression along the length of the spine as somebody with thick spinal segments but they are going to be more quote unquote bendy if you will”