Definition of eccentric
Against or in the opposite direction of contraction of a muscle. (E.g., flexion of the lower arm (bending of the elbow joint) by an external force while contracting the triceps and other elbow extensor muscles to control that movement.
Examples of eccentric in the following topics:
- Exercise damages muscles due to eccentric and concentric muscle loading.
- Resistance training, and particularly high loading during eccentric contractions, results in delayed onset muscle soreness (DOMS).
- Acute inflammation of the muscle cells, as understood in exercise physiology, can result after induced eccentric and concentric muscle training.
- Participation in eccentric training and conditioning, including resistance training and activities that emphasize eccentric lengthening of the muscle including downhill running on a moderate to high incline can result in considerable soreness within 24 to 48 hours, even though blood lactate levels, previously thought to cause muscle soreness, were much higher with level running.
- These substances then stimulate the free nerve endings in the muscle; a process that appears accentuated by eccentric exercise, in which large forces are distributed over a relatively small cross-sectional area of the muscle.
- Exercise damages muscles due to eccentric and concentric muscle loading and often results in delayed onset muscle soreness (DOMS).
- Isotonic muscle contractions can be either concentric (muscle shortens) or eccentric (muscle lengthens).Concentric ContractionsA concentric contraction is a type of muscle contraction in which the muscles shorten while generating force.
- Eccentric ContractionsAn eccentric contraction results in the elongation of a muscle.
- During an eccentric contraction, the muscle elongates while under tension due to an opposing force which is greater than the force generated by the muscle.
- Over the short-term, strength training involving both eccentric and concentric contractions appear to increase muscular strength more than training with concentric contractions alone.
- Exercise resulting in eccentric contractions at high loading can cause muscle soreness, indicative of muscle tearing, and reduced or impaired muscle function.
- This is specifically caused by eccentric exercise altering muscle ultrastructure and sarcoplasmic reticulum functioning.
- Muscle soreness, once thought to be due to lactic acid accumulation, has more recently been attributed to small tearing of the muscles fibers caused by eccentric contraction.
- The tibialis anterior functions to stabilize the ankle as the foot hits the ground during the contact phase of walking (eccentric contraction) and acts later to pull the foot clear of the ground during the swing phase (concentric contraction).
- Lymphocytes are distinguished by having a deeply staining nucleus that may be eccentric in location and a relatively small amount of cytoplasm.
- The umbilical cord inserts into the chorionic plate (has an eccentric attachment).