The knee joint functions as a stabilizer for the lower extremity during weight bearing and allows large range of motion for various functional activities. The two primary articulations of the knee joint are the tibiofemoral joint and the patellofemoral joint.
1. electrocardiogram recorded between one limb and two other limbs. The augmented leads are designated aVF, aVL, and aVR for recordings made between the foot (left), left arm, and right arm, respectively, and the other two limbs. The definition information for augmented lead is provided by Stedman's.
1 Often this is the lead with the smallest QRS. 2  The QRS axis is perpendicular to that lead's orientation (see above diagram). 3  Since there are two perpendiculars to each isoelectric lead, chose the perpendicular that best fits the direction of the other ECG leads.