For example, the average resting heart rate should remain between 60 to 100 beats per minute, according to the National Institutes of Health. Without negative feedback loops, there would be little regulation of crucial physiological functions.or example, the average resting heart rate should remain between 60 to 100 beats per minute, according to the National Institutes of Health. Without negative feedback loops, there would be little regulation of crucial physiological functions.
Medical Definition of flexion. 1  1: a bending movement around a joint in a limb (as the knee or elbow) that decreases the angle between the bones of the limb at the jointâcompare extension 2. 2  2: a forward raising of the arm or leg by a movement at the shoulder or hip joint.
Legs together and knee straight; Toes pointing straight forwards; Arms by the side; Palms facing forwards; Movements. Flexion and Extension . Flexion is a movement in the sagittal plane, which decreases the angle at the moving joint. Extension is the opposite movement, which increases the angle at the joint. Many types of synovial joint are capable of flexion and extension (hinge; ball and socket; saddle; condyloid) including the shoulder, elbow, wrist, hip and knee.