Efficient erect adult human posture is believed to reflect the least amount of physical activity required to maintain body position in space [ 8- 12], and which minimises anti-gravity stresses on body tissues.
When in doubt, medial integrity could be tested by gravity stress radiography.
To solve this problem Michelson proposed a gravity stress test [86].
The main limitation of the gravity stress radiograph is the inability to control dorsiflexion and plantar flexion.
Such a hypothesis for the existence of "altered gravity stress proteins" is discussed.
The gravity stress radiograph has provided the best results in detection of deltoid ligament rupture in patients with SE ankle fractures.
To represent the weight of the overlying strata not included in the model, an additional vertical gravity stress was calculated and loaded on the model's upper surface.
The reported amount of widening of the medial clear space as indicative for a positive external rotation stress test or gravity stress test varies [19, 25, 36, 41, 44, 46, 57, 75, 78, 86, 99, 102, 117].
None of these has shown to possess the combination of being cost-effective, reliable and easy to use; currently gravity stress radiography is favoured and, in cases of doubt, arthroscopy could be of value.
Ground pressure consists of gravity stress and tectonic stress: sigma_{text{s1}} = gamma H + lambda gamma H = (1 + lambda )gamma H (6). Abutment stress is expressed as: sigma_{text{s2}} = (k - 1 gamma H (7). In particular, when mining approaches to faults, the rockburst induced by fault slipping takes a dominant position.
Particularly, the bending force in young trees and seedlings could be much larger than gravity stress.
