what is an eccentric muscle contraction

An Overview of Eccentric Muscle Contraction

• Examples. Eccentric contractions are essentially the yin to concentric contractions' yang. ...
• Biomechanics. When used in medicine, the term "eccentric" means "away from the center." This is an apt way to describe when a muscle is both activated and lengthened.
• Negative Work. Eccentric muscle contraction produces negative work. ...
• Benefits. ...

Full Answer

What is the eccentric phase of a squat?

What’s The Difference Between An Eccentric Squat And Concentric Squat?

1. Weight Used. The eccentric squat will use heavier weights, as muscles are stronger at resisting load while they’re lengthening.
2. Range Of Motion Emphasized. The eccentric squat places a greater emphasis on the eccentric (descending) phase of the squat, which is when your muscles are actively lengthening.
3. Exercise Purpose. ...
4. Equipment Needed. ...
5. Tempo. ...

What are examples of eccentric exercises?

• Squats
• Leg Extensions
• Lunges
• Zercher Squats
• Leg Press
• Lunges
• Pistol Squats

What are examples of concentric exercises?

What are some concentric movements?

• lifting objects.
• bicep curl.
• extending from a pushup.
• standing from a squat.
• hamstring curls.
• situps.

What is eccentric phase of exercise?

What is the eccentric phase? Eccentric is the lowering phase of a movement when the muscles under contraction are lengthening. So when you're slowly lowering the dumbbell under control back to the starting position, that's the eccentric phase. This is also known as the “negative” phase.

What is an example of an eccentric contraction?

Eccentric contraction occurs when the total length of the muscle increases as tension is produced. For example, the lowering phase of a biceps curl constitutes an eccentric contraction. Muscles are capable of generating greater forces under eccentric conditions than under either isometric or concentric contractions.

What is eccentric and concentric muscle contraction?

In a concentric contraction, the muscle tension rises to meet the resistance then remains stable as the muscle shortens. During eccentric contraction, the muscle lengthens as the resistance becomes greater than the force the muscle is producing.

What are examples of eccentric exercises?

Examples of eccentric exercises include:Lowering the barbell toward your chest in a bench press.Lowering into a parallel squat position in a squat.Lowering into the bottom of a pushup.Bringing a barbell back to the ground at the end of a deadlift.Lowering your torso back to the ground in a situp.More items...•

What is the meaning of eccentric movement?

Overview. Eccentric contraction refers to any movement that lengthens a muscle at the same time it is being contracted. 1 It is a braking force that directly opposes the shortening of a muscle (known as a concentric contraction).

How do you remember eccentric and concentric?

A simple method to learn the difference between Eccentric and Concentric contractionsConcentric = Collapsing (shorter)Eccentric = Elongating (longer)Concentric phase: ... Eccentric phase: ... [NOTE: The answers are below the 3rd questions]During the concentric phase of the squat what happens to the quadriceps?More items...•

What are the 3 types of muscle contractions?

There are 3 main types of muscle contractions: Isometric, Eccentric, and Concentric.

Is walking eccentric or concentric?

Stepping upstairs involves what are called concentric muscle contractions, meaning your leg muscles (quadriceps in this case) shorten when you step up. Walking downstairs involves eccentric contractions, during which your quadriceps muscles stretch.

Is a push up concentric or eccentric?

During a pushup, your chest muscles and triceps work concentrically as you push up, and eccentrically as you lower back down.

Is a sit up concentric or eccentric?

Every time you sit up from a chair or as you are getting out of bed, your core performs a series of concentric muscle contractions to allow you to do this with balance and control.

Why is eccentric contraction important?

Eccentric contractions play an important role in everyday human movements, including mobility, stability, and muscle strength. Shortly after the sliding filament theory of muscle contraction was introduced, there was a reluctant recognition that muscle behaved as if it contained an “elastic” filament.

Why is eccentric exercise important?

Eccentric exercises strengthen not just your muscles, but also your body's connective tissues, helping to both rehab any aches and pains as well as prevent injuries ranging from tendinitis to ACL strains!

Which of the following best describes an eccentric action?

Which of the following definitions BEST describes an eccentric muscle contraction? During the movement, the muscle's attachments move farther apart from each other.

What is the difference between concentric eccentric and isometric muscle contractions?

A concentric contraction causes muscles to shorten, thereby generating force. Eccentric contractions cause muscles to elongate in response to a greater opposing force. Isometric contractions generate force without changing the length of the muscle.

What are the 2 types of muscle contractions?

Isotonic contractions – these occur when a muscle contracts and changes length and there are two types:Isotonic concentric contraction – this involves the muscle shortening. ... Isotonic eccentric contraction – this involves the muscle lengthening whilst it is under tension.

What is an example of a concentric exercise?

Concentric Exercises Think of a concentric exercise simply as the opposite of an eccentric movement. In a bicep curl, it's the portion of the workout where you're raising the dumbbell up towards you. Other common concentric movements include: Lifting an object off the ground – first half of a deadlift.

Is walking concentric or eccentric?

Stepping upstairs involves what are called concentric muscle contractions, meaning your leg muscles (quadriceps in this case) shorten when you step up. Walking downstairs involves eccentric contractions, during which your quadriceps muscles stretch.

How do concentric and eccentric contractions work?

Although concentric contractions are effective in triggering muscle growth , the controlled use of both concentric and eccentric contractions can ensure greater, all-around strength by stabilizing the muscles in and around a joint. 3 . Eccentric contractions generally involve a lowering or releasing movement, while concentric contractions generally ...

How does eccentric contraction help in athletic training?

3 . Athletic training commonly uses plyometrics and eccentric exercises to build muscle strength and endurance. Running, sprinting, jumping, hopping, and throwing a ball all use eccentric contraction to deliver power.

What is the difference between eccentric and concentric contractions?

Eccentric contractions generally involve a lowering or releasing movement, while concentric contractions generally infer lifting or rising. For example, when you lift a barbell, you are using concentric contractions; as you lower it, eccentric contractions are at play.

Why is eccentric exercise more likely to cause delayed onset muscle soreness?

While eccentric exercise is more likely to cause delayed onset muscle soreness (DOMS), repeating the exercise a week or so later will invariably decrease DOMS symptoms. 3 

What is a concentric contraction?

When you think about muscle contractions, most people will assume this to mean a concentric contraction, such as a biceps curl, in which the muscle simultaneously contracts and shortens.

What does eccentric mean in medicine?

When used in medicine, the term "eccentric" means "away from the center.". This is an apt way to describe when a muscle is both activated and lengthened. During an eccentric contraction, the muscle will be challenged by an opposing force, such as a heavy weight or gravity. Even though the muscle is able to oppose the force, ...

What is elastic recoil?

Elastic recoil is energy that can be used for the next movement. For example, if you are doing squats, the lifting (concentric) phase utilizes energy, while the squatting (eccentric) phase absorbs energy and potentiates the next concentric movement. It is not dissimilar to the action of springs in which absorbed energy is converted ...

What is eccentric muscle contraction?

Eccentric contractions, characterized by the lengthening of the muscle-tendon complex, present several unique features compared with other types of contractions, which may lead to unique adaptations. Due to its specific physiological and mechanical properties, there is an increasing interest in employing eccentric muscle work for rehabilitation and clinical purposes. However, unaccustomed eccentric exercise is known to cause muscle damage and delayed pain, commonly defined as “Delayed-Onset Muscular Soreness” (DOMS). To date, the most useful preventive strategy to avoid these adverse effects consists of repeating sessions involving submaximal eccentric contractions whose intensity is progressively increased over the training. Despite an increased number of investigations focusing on the eccentric contraction, a significant gap still remains in our understanding of the cellular and molecular mechanisms underlying the initial damage response and subsequent adaptations to eccentric exercise. Yet, unraveling the molecular basis of exercise-related muscle damage and soreness might help uncover the mechanistic basis of pathological conditions as myalgia or neuromuscular diseases. In addition, a better insight into the mechanisms governing eccentric training adaptations should provide invaluable information for designing therapeutic interventions and identifying potential therapeutic targets.

Why is eccentric training important?

Indeed, because of its distinct characteristics, eccentric training modalities can further enhance maximal muscular strength and optimize improvements to power, optimal muscle length for strength development, as well as coordination during eccentric tasks (LaStayo et al., 2003a).

Why is plyometric exercise important?

Plyometric exercises, such as drop jump, is frequently used to improve speed and jumping ability in athletes. The literature recommends specific habituation training and knowledgeable supervision due to the inherent risk of injuries in such exercises (Hoppeler, 2016).

Does eccentric training increase muscle strength?

The mechanical origin of initial muscle damage has led authors to suggest that changes in mechanical properties of the musculoskeletal system could render the muscle more resilient to EIMD. With respect to this hypothesis, both the passive and dynamic stiffness of the muscle-tendon complex has been shown to increase after eccentric training (Howell et al., 1993; Reich et al., 2000). These modifications have been, respectively, attributed to an increase in intramuscular connective tissue improving the ability to withstand myofibrillar stress and to a reinforcement of intermediate filament system, in charge of maintaining the alignment and structure of the sarcomeres (i.e., titin, desmin) (McHugh, 2003). In agreement with the reorganization of cytoskeletal proteins, the level of certain structural proteins, such as desmin, was found to increase in the days following eccentric exercise (Feasson et al., 2002; Lehti et al., 2007). This suggests that muscle-specific cytoskeletal remodeling could play a role to protect from future sarcomere disruption. Desmin, the major protein of the muscle intermediate filament, would act as mechanical integrator for the repair of the filaments (Yu et al., 2002). Its reinforcement secondary to transcriptional upregulation may provide mechanical protection from future sarcomere disruption (Peters et al., 2003). However, some studies showing that stiffer muscles are more prone to damage questioned the mechanical theory (McHugh et al., 1999b). Moreover, desmin knockout (KO) mice have been found to exhibit less exercise-induced than wild-type mice (Sam et al., 2000). This finding was, however, imputed to more compliant muscles of KO mice. Recent works have suggested that in addition to their function of structural support to the cell, the intermediate filaments may play an active role in biological processes such as signaling, mechanotransduction and gene regulation. The mechanisms behind these processes are not well understood. Desmin, which is responsible for transmission of stress among myofibrils appears to be required for the maintenance of myofiber alignment, nuclear deformation, stress production and JNK-mediated stress sensing (Palmisano et al., 2015). Growing evidence supports the role of the skeletal muscle intermediate filaments as a stress-transmitting and stress-signaling network. Notably, cytoskeletal proteins help mitochondria not only in their movement and proper cellular positioning, but also to maintain their biogenesis, morphology, function, and regulation of energy fluxes. The functionality of these cytoskeletal proteins may thus influence the mitochondria functions, including the regulation of Ca2+signals and apoptosis (Mado et al., 2019). Remodeling of the intermediate filaments network may also impact cell migratory behaviors important to development (Sanghvi-Shah and Weber, 2017).

Does eccentric exercise cause muscle damage?

Indeed, eccentric exercise induces greater muscle damage and negative functional consequences in an healthy naïve muscle than other types of exercise (Friden and Lieber, 1992). Indeed, the combination of high force and reduced recruitment of fiber number during eccentric contractions causes a high mechanical stress on the involved structures that may lead to focal microlesions of the muscle fibers (Lieber and Friden, 1999). Numerous histological studies described widespread Z-line streaming with myofibrillar disruption and necrosis following intense and/or unaccustomed eccentric exercise (Friden and Lieber, 1998; Crameri et al., 2007; Lauritzen et al., 2009). The sarcomeric disorganization has been associated with disruptions to the sarcolemma and the extracellular matrix, swelling of mitochondria, dilation of the transverse tubule system and fragmentation of the sarcoplasmic reticulum (Takekura et al., 2001; Crameri et al., 2004). Sarcolemmal disruption may be highlighted by the appearance of sarcoplasmic proteins into the blood (as creatine kinase, CK and myoglobin, Mb) or by the cytoplasmic accumulation of proteins that are normally not present in muscle fibers (as albumin and immunoglobulins) (McNeil and Khakee, 1992; Clarkson and Hubal, 2002). Vital dye such as Evans blue is also used in rodents to demonstrate increased sarcolemmal permeability (Hamer et al., 2002). Damage to extracellular matrix and connective tissue components also occur following a novel eccentric exercise (Brown et al., 1997; Crameri et al., 2007). Morphological abnormalities observed immediately after exercise gradually extent to a larger number of muscle fibers and appear exacerbated 2–3 days post-exercise (Friden et al., 1983a). These observations have led authors to define primary and secondary damage phases (Morgan and Allen, 1999). Both human and animal studies supported that Type II (in particular IIb) muscle fibers are more damaged after eccentric exercise than Type I fibers (Friden et al., 1983b; Jones et al., 1986; Lieber and Friden, 1988). Several hypotheses could explain the higher susceptibility of Type II fibers to exercise-induced muscle damage (EIMD). Among these are differences in their structural composition (Z-line, fiber type specific protein isoforms such as titin), a reduced oxidative capacity, a lower ability to regulate calcium homeostasis or a selective recruitment of fast-twitch muscle fibers during eccentric contraction (Lieber and Friden, 1999; McHugh et al., 1999a; Byrne et al., 2004).

Does eccentric exercise increase sarcomeres?

Another group of theories explaining the RBE relies on cellular adaptation. Given the focal feature of muscle damage, speculation has been made that the muscle becomes more resistant to EIMD thanks to the removal of stress-susceptible fibers or sarcomeres resulting from the initial eccentric bout (Armstrong, 1984; Newham et al., 1987). However, this is inconsistent with the fact that the initial bout does not have to cause appreciable damage to confer a protective effect. Several works provided evidence that eccentric exercise promotes an increase in series sarcomeres (Lynn and Morgan, 1994; Yu et al., 2004). Such longitudinal addition of sarcomeres is thought to contribute to the protective effect as it would avoid the sarcomere stretching beyond their overlap and thus, their disruption. The sarcolemma and sarcoplasmic reticulum would also become stronger following the initial bout of eccentric exercise (McHugh, 2003). This may limit perturbations of calcium homeostasis and thus, may prevent the calpain activation and the degradation of cytoskeletal proteins. The reduced calpain activity could then explain the attenuation of mitochondrial dysfunction following chronic exposure of eccentric exercise. Other potential adaptations such a decreased susceptibility to calcium-induced mPTP (mitochondrial permeability transition pore) opening or upregulation of heat shock proteins, in particular Hsp70, may also be contribute to protect mitochondrial function (Rattray et al., 2013). In addition, changes in the inflammatory response, such as a reduced activation of the monocytes and neutrophils, have been described after repeated eccentric bouts and may also be related to the RBE (Pizza et al., 1996). Nevertheless, whether adaptation in the inflammatory process is the cause or a consequence of reduced muscle damage is not elucidated. Adaptation may also rely on the monocyte chemoattractant protein 1 (MCP-1), a chemokine involved in activation and attraction of inflammatory cells. Indeed, MCP-1 is dramatically overexpressed at the transcript level after a single bout of eccentric exercise and it appeared even more upregulated after a second bout (Hubal et al., 2008). Authors have thus suggested that MCP-1 enhances muscle recovery after a repeated bout of eccentric exercise via improved signaling between macrophages and satellite cells. Other chemokines may contribute to the protective adaptation to exercise-induced muscle damage. Upregulation of CCL2 and a decreased of NF-kB DNA-binding activity occur following repeated bouts of eccentric exercise. These observations supports the hypothesis that the immune response becomes more efficient to promote the regeneration of muscle tissue after an initial bout of eccentric exercises, notably through enhancement in inflammatory cell infiltration into the muscle and myoblast proliferation (Peake J. et al., 2005). Furthermore, a remodeling of the surrounding extracellular matrix might also occur during the RBE. A strengthening of the extracellular matrix such as an improved integrin support may help to recover faster after eccentric contractions (Hyldahl et al., 2015).

What is eccentric contraction?

Eccentric contraction. Eccentric contraction occurs when the total length of the muscle increases as tension is produced. For example, the lowering phase of a biceps curl constitutes an eccentric contraction.

What is the force produced by a muscle during eccentric contraction?

The force produced by a muscle during eccentric contraction depends on the speed of lengthening, which depends on the size of the external load. The greater the external load (in relation to the isometric strength of the muscle), the greater the speed of lengthening. The greater the speed of lengthening, the greater the effect ...

How does a muscle contract isometrically?

When the amount of force produced by a muscle (muscle–tendon unit) just matches the external load, the muscle contracts isometrically. The maximum load the muscle can sustain isometrically is called the isometric strength of the muscle. When the external load is less than isometric strength, the muscle is able to contract concentrically. The speed of shortening in a concentric contraction depends on how much force the muscle needs to produce to move the external load. The greater the external load, the greater the muscle force needs to be, and the greater the muscle force (as a proportion of isometric strength), the slower the speed of shortening. A muscle can shorten at maximum speed when the external load on the muscle is zero. When the external load on a muscle is greater than the isometric strength of the muscle, it is forced to lengthen (contract eccentrically).

How does speed of shortening affect concentric contraction?

The speed of shortening in a concentric contraction depends on how much force the muscle needs to produce to move the external load. The greater the external load, the greater the muscle force needs to be, and the greater the muscle force (as a proportion of isometric strength), the slower the speed of shortening.

Which type of contraction requires less energy than the other two types?

In a concentric contraction, the force generated by the muscle is less than the muscle’s maximum, and the muscle begins to shorten. This type of contraction is widely known as muscle contraction. It requires more energy compared to the other two types, but this contraction generates the least force. −.

When a muscle is shortened at maximum speed, what is the external load?

A muscle can shorten at maximum speed when the external load on the muscle is zero. When the external load on a muscle is greater than the isometric strength of the muscle, it is forced to lengthen (contract eccentrically). In an eccentric contraction a muscle resists the stretching load. In so doing, the attached cross bridges are themselves ...

What happens when the external force exceeds the maximum strength of the muscle?

When the external force exceeds the maximum strength of the muscle, the muscle and its tendon will be damaged.

What is eccentric contraction?

An eccentric contraction is the motion of an active muscle while it is lengthening under load. Eccentric training is repetitively doing eccentric muscle contractions. For example, in a biceps curl the action of lowering the dumbell back down from the lift is the eccentric phase of that exercise — as long as the dumbbell is lowered slowly rather than letting it drop (i.e., the biceps are in a state of contraction to control the rate of descent of the dumbbell).

What does it mean when a muscle is eccentric?

Eccentric contraction means lengthening of muscle fiber and slow down the movement of joint

How do eccentric and concentration contractions work?

Concentric contractions allow force to be applied to a weight by pulling on the bone the muscle is attached to (by shortening), while eccentric contractions control the reduction of that force by relaxing and elongating the muscle.

How does the deltoids contract in real life?

It is used often in real life. If you raise your arm up to get a plate off a high shelf the deltoids contract concentrically to get the arm up but, as your are bringing it down, they must contract eccentrically so the plate does not come crashing down in response to gravity. Another example is descending stairs. You will get to the bottom, gravity guarantees that, but you probably want to do without broken limbs and a concussion. To descend safely the quads have to contract eccentrically, allowing your knee to

Which contractions allow force to be applied to a weight by pulling on the bone the muscle is attached to?

Concentric contractions allow force to be applied to a weight by pulling on the bone the muscle is attached to (by shortening), while eccentric contractions control the reduction of that force by relax

Why are muscles hard and contracted when a person dies?

It requires actin, myosin, and ATP. The muscles contract spontaneously or with stimulation but to relax requires ATP. This is why muscles are hard and contracted when a person dies (rigor mortis).

What are the three types of muscle tissue?

Figure: The body contains three types of muscle tissue: skeletal muscle, smooth muscle, and cardiac muscle, visualized here using light microscopy. Smooth muscle cells are short, tapered at each end, and have only one plump nucleus in each. Cardiac muscle cells are branched and striated, but short. The cytoplasm may branch, and they

What are some examples of concentric contractions?

An example of a concentric muscle contraction is picking up a heavy box. If you squat down to lift a box, your arm muscles may contract to hold the weight, but your leg muscles tighten as you stand up with the additional weight.‌. Eccentric Contractions.

How do you use isometric muscle contractions?

‌ Isometric muscle contractions. This type of contraction is used when your muscle stays in a single position and the attached joint doesn’t move. It doesn’t provide overall strengthening to the muscle group. Instead, it strengthens your muscle for that single, specific movement.

What type of contraction happens when you lower something heavy?

Eccentric muscle contractions also happen when you lower something heavy. Your muscle has to remain tight to manage the weight, but it lengthens to shift the weight into a different position.‌‌. Isometric Contraction. This type of muscle contraction happens when your muscle is actively held at a set length. Instead of lengthening and shortening as ...

What is the fiber that makes muscles contract?

How Your Muscles Contract. ‌Your muscles contain fibers called myosin. Depending on how you need to use your muscles, the myosin fibers either tighten up and shorten or loosen up and stretch out. Myosin is also responsible for muscle contractions like your heartbeat that happens at regular intervals.

What is passive muscle contraction?

Passive Stretch. This type of muscle contraction happens when your muscle is passively lengthened. For example, you lean down to touch your toes. There’s no additional weight that your hamstring muscle needs to hold or lift by applying force, but it still stretches from the movement. How You Use Muscle Contractions.

Why do muscles contract?

Your muscles contract for any number of reasons, but they primarily do the following:‌. Offer stability to your joints and connective tissues – Your muscles lengthen and shorten, sometimes involuntarily, as your body needs them. Produce heat to maintain your body temperature – Around 40% of your body’s temperature converts into muscle work.

What is an example of a contraction?

An example of this type of contraction is carrying something in your arms in front of you. You aren’t trying to raise or lower the object but keep it at a steady position.‌.

WHY YOU SHOULD FOCUS ON CONCENTRIC, ECCENTRIC & ISOMETRIC CONTRACTION IN YOUR TRAINING?

But we didn't really emphasize the importance of isometric contraction, which is to gain strength at specific ranges in a movement.

Which is better, eccentric or concentric?

Deciding on which is better does come down to what your goals are. Some people like to focus on their concentric contractions for their specific sports or to build power, while others like to focus on eccentric contractions to use heavier loads to build muscle and strength.

WHAT IS AN ISOTONIC EXERCISE?

While isotonic exercises can further fall into two different categories of concentric and eccentric movement, let's not get ahead of ourselves.

What are the two major phases of isotonic movement?

An isotonic movement breaks down into two major phases: a concentric phase and an eccentric phase. In the simplest explanation, the concentric phase of a movement is when you are contracting (shortening) the muscle, and the eccentric is when you are lengthening the muscle.

How to visualize isotonic exercise?

A good way of visualizing it is by thinking about pausing at any point during an isotonic exercise and holding the position. i.e., holding your position midway through a push-up.

What muscles do you work when you bend down?

This phase will mainly affect the lower back, glutes, and hamstrings. It is fairly straightforward. As you bury your feet into the ground and lift the weight, these muscles will start to contract.

When do you reach the final position of the concentric phase?

You will eventually reach the final position of the concentric phase when the muscles are fully contracted (or nearly in full contraction). This is when you are standing upright.