Abu Hurairah (RadiyAllahu anhu) reported: Messenger of Allah (Sallellahu alaihi wa sallam) said: "On every joint of man, there is charity (Sadaqah), on everyday when the sun rises: doing justice between two men is charity, and assisting a man to ride an animal or to load his luggage on it is charity; and a good word is charity, every step which one takes towards (the mosque for) Salat is charity, and removing harmful things from the way is charity".
[Al-Bukhari and Muslim].
Almighty Allah has made human body flexible, that is to say, its parts have joints which enable him to make all kinds of movements. If human beings did not have these joints, it would not have been possible for its different parts to make movements which they do. Had it been so, one would not have been able to use various parts of his body as he likes. Thus, these joints are a valuable gift from Allah for which one should always be grateful to Him. In all, a person has three hundred and sixty joints in his body, as has already been stated in a Hadith narrated earlier. According to some Ahadith, two Rak`ah of Duha prayer (optional forenoon prayer) has been regarded sufficient for this purpose, while in others, it has been stated that if one cannot do anything else for expressing gratefulness to Allah, he should refrain from harming others as it is a form of Sadaqah.