A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs and the stable balance of attractive and repulsive forces between atoms when they share electrons is known as covalent bonding.ovalent bonding is implied in the Lewis structure by indicating electrons shared between atoms. The term covalence in regard to bonding was first used in 1919 by Irving Langmuir in a Journal of the American Chemical Society article entitled The Arrangement of Electrons in Atoms and Molecules.
Causes. Leg length discrepancies can be caused by poor alignment of the pelvis or simply because one leg is structurally longer than the other. Regardless of the reason, your body wants to be symmetrical and will do its best to compensate for the length difference.
1 Many causes of leg pain are obvious, such as injury after an accident. 2  Leg pain can have less obvious causes, such as peripheral artery disease.  Repetitive, excessive sports, especially in the form on running, can lead to trauma that creates leg pain - E.G: shin splints and stress fractures.