What are the forearm and the shin in the context of a woman's 'awrah in front of her mahrams, and is it permissible to touch above the elbow from over a barrier if this limb is part of a woman's 'awrah in front of her mahrams?

If a pilgrim (muhrim) needs to touch above the elbow of his female relative (mahramah) from behind her clothes, it is permissible for him to do so if there is no fear of temptation (fitnah), as this usually does not lead to lust. However, if there is no need, it is recommended to abstain. Ibn Umar carried a man who was carrying his mother while circumambulating the Kaaba, and he did not object to it. It is permissible for a son to touch his mother's belly and back from behind her clothes, and it is permissible to touch the shin from behind the clothes. As for touching the thigh, there is a difference of opinion regarding it.