With negative ulnar variance, the load across the TFC is decreased. This occurs during supination, because the radius moves distally on the ulna and creates a negative ulnar variance. With positive ulnar variance it is reversed. The load that is transmitted across the TFC is then increased. This positive ulnar variance occurs during pronation.[8]
Radioulna ligament ;During supination the superficial palmar and the deep dorsal ligaments are tighten, they prevent palmar translation of the ulna. In pronation this is reversed, the superficial dorsal and the deep palmar ligaments are tighten. They prevent dorsal translation of the ulna in pronation.