It is accompanied by the branch of the femoral nerve to the vastus lateralis muscle.

The lateral retinaculum is an extension of the fibrous 'aponeurosis' of the vastus lateralis muscle (itself a part of the quadriceps muscles making up the 'lap').

Intramuscular injections are often given in the deltoid muscle of the arm, the vastus lateralis muscle of the leg, and the ventrogluteal and dorsogluteal muscles of the buttocks.

In untrained individuals, the proportion of ST fibers in the vastus lateralis muscle (the largest of the quadriceps muscles and the most commonly studied muscle in humans), is typically around 55%, with FT a fibers being twice as common as FT b fibers (Saltin et al. 1977).