While experts claim stretches can be held from as little as 10 seconds to feel the benefit and up to minutes at a time, it’s both dependent on the individual and the type of stretch.
What does the stretch reflex do?
The stretch reflex ( myotatic reflex ), or more accurately "muscle stretch reflex", is a muscle contraction in response to stretching within the muscle. The reflex functions to maintain the muscle at a constant length. The term deep tendon reflex is often wrongfully used by many health workers and students to refer to this reflex.
What is the dynamic phase of the stretch reflex?
The static component of the stretch reflex is in place as long as the muscle is stretched. The dynamic phase occurs only when the muscle is stretched e.g. when the tendon is struck with a tendon hammer. When the muscle is stretched, they send an impulse via the sensory neurons to the relevant spinal cord segment.
How do I get the most out of the stretch reflex?
To get the most out of the stretch reflex, the muscles and nervous system should be fresh. Thus, speed and explosive exercises should always be done at the beginning of training after you have undergone a vigorous warm up to prepare the muscles for this work. When fatigue sets in, do not use the stretch reflex.
How long should you hold stretches to feel the benefits?
While experts claim stretches can be held from as little as 10 seconds to feel the benefit and up to minutes at a time, it’s both dependent on the individual and the type of stretch.
How do I get rid of my stretch reflex?
Stop contracting stretching muscle. 4. You should feel release in stretching muscle; if so move deeper into pose....Create very mild, pleasant stretch.Hold perfectly still until sensation of stretch fades or disappears.Slowly move deeper into pose, just enough to reinstate same mild, pleasant stretch.Repeat.
What triggers the stretch reflex?
The receptor responsible for initiating a stretch reflex is the muscle spindle. Muscle spindles are found in almost all skeletal muscles and are particularly concentrated in muscles that exert fine motor control (e.g., the small muscles of the hand and eye).
Is stretch reflex normal?
The stretch reflex (myotatic reflex), or more accurately "muscle stretch reflex", is a muscle contraction in response to stretching within the muscle. The reflex functions to maintain the muscle at a constant length....Clinical significance.GradeResponseSignificance4+clonusalways abnormal4 more rows
Are stretch reflexes automatic?
Our brain is sending the voluntary message to manually stretch our muscles by pulling on them. But despite all our efforts, our stretch reflex is automatically kicking in, contracting our muscles to prevent us from overstretching and tearing our muscles, tendons, and ligaments.
What happens in stretch reflex?
The stretch reflex is activated (or caused) by a stretch in the muscle spindle. When the stretch impulse is received a rapid sequence of events follows. The motor neuron is activated and the stretched muscles, and its supporting muscles, are contracted while its antagonist muscles are inhibited (relaxed).
What is hyperactive stretch reflex?
Hyperactive stretch reflexes are seen when there is interruption of the cortical supply to the lower motor neuron, an "upper motor neuron lesion." The interruption can be anywhere above the segment of the reflex arc. Analysis of associated findings enables localization of the lesion.
Why does the body automatically stretch?
Pandiculation is your body's way of releasing tension in your fascia, the connective tissue that surrounds your muscles, organs and blood vessels. Stretching is one of the ways that our body keeps fascia flexible and full of oxygen. Sometimes, your body will stretch involuntarily to achieve this result.
What purpose do stretch reflexes serve?
Functions. The first major function of the stretch reflex is muscle protection. When a muscle length increases, the muscle spindle within that muscle stretches, and its nerve activity will increase. Resulting from this is increased alpha motor neuron activity.
What is the difference between stretch and tendon reflex?
The stretch reflex operates as a feedback mechanism to control muscle length by causing muscle contraction. In contrast, the tendon reflex operates as a negative feedback mechanism to control muscle tension.
What stimulates tendon reflexes?
Tendon reflexes are single synapse reflexes. A rapid stretch of the muscle stimulates the muscle spindles and this message is conveyed via the sensory root to the spinal cord at the segmental level of the muscle stimulated.
What causes muscle stretch?
The stretching of a muscle fiber begins with the sarcomere, the basic unit of contraction in the muscle fiber. As the sarcomere contracts, the area of overlap between the thick and thin myofilaments increases (discussed above). As it stretches, this area of overlap DECREASES, allowing the muscle fiber to elongate.
Why does the body automatically stretch?
Pandiculation is your body's way of releasing tension in your fascia, the connective tissue that surrounds your muscles, organs and blood vessels. Stretching is one of the ways that our body keeps fascia flexible and full of oxygen. Sometimes, your body will stretch involuntarily to achieve this result.
What happens in a stretch reflex quizlet?
The stretch reflex (myotatic reflex) is a muscle contraction in response to stretching within the muscle. It is a monosynaptic reflex which provides automatic regulation of skeletal muscle length. When a muscle lengthens, the muscle spindle is stretched and its nerve activity increases.
What Activates the Stretch Reflex?
The stretch reflex is activated (or caused) by a stretch in the muscle spindle. When the stretch impulse is received a rapid sequence of events follows. The motor neuron is activated and the stretched muscles, and its supporting muscles, are contracted while its antagonist muscles are inhibited (relaxed).
What is the muscle spindle reflex?
The stretch reflex (also called the myotatic reflex, the muscle stretch reflex and sometimes the knee-jerk reflex), is a pre-programmed response by the body to a stretch stimulus in the muscle. When a muscle spindle is stretched an impulse is immediately sent to the spinal cord and a response to contract the muscle is received. Since the impulse only has to go to the spinal cord and back, not all the way to the brain, it is a very quick impulse. It generally occurs within 1-2 milliseconds.
How does the deep tendon reflex work?
If a muscle is put under excessive tension (contraction) the golgi tendon organs (GTO’s) are excited and the deep tendon reflex is activated, which causes the muscles to relax, thereby protecting the muscle from being over stretched or torn. Note that in day-to-day movement, tension in the muscles is not sufficient to activate the GTO’s deep tendon reflex. By contrast, the threshold of the muscle spindle stretch reflex is set much lower.
What is the body's response to stimulus?
Another automatic response by the nervous system is the reflex. The body reacts in a predetermined way based on specific stimulus. This may be a practiced response or a pre-programmed one. The stretch reflex (or myotatic reflex) is one of those responses.
Why is the stretch reflex important?
It helps maintain proper posturing because a slight lean to either side causes a stretch in the spinal, hip and leg muscles to the other side , which is quickly countered by the stretch reflex. This is a constant process of adjusting and maintaining.
How long does it take for a stretch reflex to occur?
Since the impulse only has to go to the spinal cord and back, not all the way to the brain, it is a very quick impulse. It generally occurs within 1-2 milliseconds. The stretch reflex is designed as a protective mechanism, to prevent strain and tear injuries to the muscles and tendons.
Why is the gamma efferent cell important?
This is important because if the muscle is working against a load and shortening during contraction and an additional load is added, the muscle recognizes the stretch immediately and can compensate with a stronger contraction. This also protects the inhibited antagonist muscles from being injured from excessive stretching.
What is a stretch reflex?
The stretch reflex can be a monosynaptic reflex which provides automatic regulation of skeletal muscle length, whereby the signal entering the spinal cord arises from a change in muscle length or velocity. It can also include a polysynaptic component, as in the tonic stretch reflex. When a muscle lengthens, the muscle spindle is stretched ...
What are the structures of stretch reflex?
In the muscle, there are muscle spindles, whose extrafusal muscle fibers lie parallel to the muscle and sense changes in length and velocity. The afferent sensory neuron is the structure that carries the signal from the muscle to the spinal cord.
How do gamma motoneurons regulate stretch reflex?
Gamma motoneurons regulate how sensitive the stretch reflex is by tightening or relaxing the fibers within the spindle. There are several theories as to what may trigger gamma motoneurons to increase the reflex's sensitivity. For example, alpha-gamma co-activation might keep the spindles taut when a muscle is contracted, preserving stretch reflex sensitivity even as the muscle fibers become shorter. Otherwise the spindles would become slack and the reflex would cease to function.
What is the supraspinal control of the stretch reflex?
Supraspinal control of the stretch reflex means the signal travels above the spinal cord before traveling back down to the same segment it entered the spinal cord from. The responses from these pathways are often termed medium or long latency stretch reflexes, because the time course is longer due to distance it needs to travel. The central nervous system can influence the stretch reflex via the gamma motoneurons, which as described above control the sensitivity of the reflex.
What happens when a muscle is stretched?
When a muscle lengthens, the muscle spindle is stretched and its nerve activity increases. This increases alpha motor neuron activity, causing the muscle fibers to contract and thus resist the stretching. A secondary set of neurons also causes the opposing muscle to relax. Gamma motoneurons regulate how sensitive the stretch reflex is by tightening ...
What is a patellar reflex?
The patellar reflex is an example of the stretch reflex. The stretch reflex ( myotatic reflex ), or more accurately "muscle stretch reflex", is a muscle contraction in response to stretching within the muscle. The reflex functions to maintain the muscle at a constant length. The term deep tendon reflex is often wrongfully used by many health ...
Which reflex has the shortest latency?
Otherwise the spindles would become slack and the reflex would cease to function. This reflex has the shortest latency of all spinal reflexes including the Golgi tendon reflex and reflexes mediated by pain and cutaneous receptors.
How long does a box squat stretch reflex last?
On the subject of the stretch reflex, however, someone said that the stretch reflex does not last four seconds as a study by Wilson (1990) states.
How long does bench pressing stretch last?
A study by Wilson (1990) concluded that while bench pressing, the stretch would last up to four seconds. At that point all started elastic energy is lost. Other studies by Chapman and Caldwell (1985) found it to be the same as Pete—0.25 seconds and the plyometric action is lost.
Is the amortization phase longer or shorter?
The idea is that the muscular force developed at the instant of going from eccentric to concentric work will be greater for a shorter amortization phase and a shorter braking time. But if you constantly add weight to the falling bar, the amortization phase will be longer and longer.
Why do we have the stretch reflex?
In general, reflexes exist to help us stay alive and avoid injury. In fact, the neurons carrying the stretch reflex messages back and forth from the spine are among the most heavily myelinated (insulated) in the body. This means that their messages travel faster and are more important to our survival than the sensations of pain, touch, and temperature.
What is the function of stretch reflex?
One critical function of the stretch reflex is that it helps us stand upright. If you suddenly lean to the right side, the postural muscles on the left side of your vertebral column are stretched. When the muscle spindles in those muscles sense that they’re being lengthened, they automatically send the message to contract to correct your posture.
What are spindles in the body?
Muscle spindles play an important role in our stretch reflex. Muscle spindles are sensory receptors located within our skeletal muscles (the type of muscles that move our skeleton around, in contrast to the smooth muscle of our internal organs). Muscle spindles detect changes in the length of our muscles, and for this reason they’re also referred ...
What is a knee jerk reflex?
The knee-jerk reflex is a great example of the stretch reflex. When the doctor taps your patellar tendon just below your knee, it stretches your patellar tendon, your quadriceps tendon, and your quadriceps muscles. The muscle spindles in your quadriceps sense the sudden increase in length and automatically send the message to contract your ...
What are spindles in muscles?
Muscle spindles detect changes in the length of our muscles, and for this reason they’re also referred to as stretch receptors. When one of your skeletal muscles is stretched—either by you pulling on it, someone else pulling on it, or by someone giving you a deep massage—the muscle spindles within that muscle are stretched too.
Why do muscles become tight?
But while your muscles became tight as a result of the automatic, often subconscious learning process of developing muscle memory, you must use a voluntary, conscious learning process to release them.
Why is stretching important?
If we’re involved in sports or physical training, we stretch to warm up, cool down, and during breaks to help us stay loose. Unfortunately, stretching usually doesn’t accomplish much, mainly due to the myotatic reflex, more commonly referred to as the stretch reflex.
How Long Should Each Stretch Last?
While experts claim stretches can be held from as little as 10 seconds to feel the benefit and up to minutes at a time, it’s both dependent on the individual and the type of stretch. According to Jeffcoat, a static stretch is achieved by holding a single position for 30 seconds, while dynamic stretching can be conducted in a rep manner for around 10-12 repetitions .
How long does it take to feel a stretch?
While experts claim stretches can be held from as little as 10 seconds to feel the benefit and up to minutes at a time, it’s both dependent on the individual and the type of stretch.
What Are Some Common Stretching Mistakes to Avoid?
Mistakes can arise in our body positioning and also the degree of stretch, such as trying too hard to push out with our stretching boundaries, risking tearing of muscle fibers . The muscle has a natural protective response called "the stretch reflex" that allows the muscle to contract in response to the stretch, but pushing beyond this resistance can cause damage and counteracts the goal of stretching.
What Simple, Yet Effective Stretches Are a Good Start for Beginners?
If stretching is a new and somewhat bewildering concept for you, it’s wise to ease into a regimen small steps at a time. Here are three of Fornarola’s suggested stretches for beginners.
How long should you stretch for a static stretch?
Similarly, Fornarola recommends holding a static stretch between 30-60 seconds to achieve a lengthening of muscles and increase in flexibility before repeating a few times to gain the full benefit of the stretch. “ An interesting rule of thumb is to stretch for one minute for every two minutes of exercise; so, for instance, if you complete a 30-minute workout, you should spend at least 15 minutes stretching.”
What is passive stretching?
“A static or passive stretch is a technique best used after exercise or sport as part of a cool-down routine ," explains Jeffcoat. "Gentle static stretching is also great for chronic pain.".
Why do we stretch in the morning?
In addition, due to inactivity, muscles and tendons become tighter during sleep, and so a gentle morning stretch is a refreshing wake up for the body. “Evening is also a perfect time to sneak in a stretch following a full day of activity, as it helps to lengthen the muscles and realign the muscular-skeletal system”.
What is the ability of the muscles to undergo a stretch and accumulate energy to produce a forceful and fast contraction?
The ability of the muscles to undergo a stretch and accumulate energy to produce a forceful and fast contraction in the shortening phase is known as muscle resiliency. This is the key to all speed and power movements (i.e. movements that involve acceleration).
Why is the stretch reflex important?
When the stretch reflex is used, it can bring about additional gains in strength and more muscle mass because of the greater development of the fast twitch fibers. However, this is only one technique for training. It is not meant to replace the other types of exercise execution. Keep in mind that variety is most important in developing muscle strength and mass. Incorporating the stretch reflex in some of the exercises is a very effective, if not the most effective, method for maximally developing the size of the fast twitch fibers.
Why do bench presses use stretch reflex?
The reason for this is that you use the energy accumulated on the down movement to execute the switch and upward acceleration of the barbell. Keep in mind that as you lower the barbell, the triceps, pectorals, and anterior deltoids undergo an eccentric contraction during which the muscles lengthen and become tenser. This muscle tension is used to stop the downward movement, switch to a brief isometric movement when the movement stops going down, and then change to the concentric contraction with which you accelerate the barbell upward. The eccentric contraction is most important for eliciting the stretch reflex and for controlling the barbell on the down phase.
What is the purpose of the fast twitch fibers?
Training the fast twitch fibers also includes the storage and release of elastic energy by the connective tissues in the muscle/tendon complex and should not be ignored by bodybuilders, powerlifters, power athletes, and endurance athletes. This is done by involving the stretch reflex, which entails accumulation of energy in the muscle-tendon complex prior to a quick explosive contraction and accelerates the weight or object held. After this, the weight or object moves on its own momentum followed by some muscle involvement until the movement stops.
What is fast twitch muscle fiber?
The fast twitch muscle fibers are sub-divided into several sub-classes and include fibers that are fast contracting and resistant to fatigue (FRF), fast contracting but more easily fatigued (FEF), and fast contracting fast fatiguing white fibers (FFF). Near-maximal and explosive resistance training produces greater hypertrophy of the fast twitch muscle fibers than the slow twitch muscle fibers.
How is explosive movement determined?
At the same time, maximal muscle power output and the potential for explosive movement is determined mainly by the proportion of fast twitch fibers. For example, weightlifters and sprinters who must do more explosive movements have a considerably higher proportion of fast twitch fibers than bodybuilders, powerlifters, and endurance athletes. High intensity is not necessarily dependent upon the use of near-maximal or maximal loads but more to the degree to which the relevant muscle fibers are recruited during the effort. The terms “fast twitch” and “slow twitch” do not necessarily mean that fast movements recruit exclusively fast twitch fibers and slow movements recruit exclusively slow twitch fibers. The fibers involved are determined by the force that is produced.
How much did Phil Murphy lose in his stretch reflex?
Phil Murphy, a former lineman for the then Los Angeles Rams football team in the early 80s, is a great example of what can be accomplished with explosive training using the stretch reflex. Phil, who was already extremely strong, was brought to me for quickness and explosive training. He weighed 352 pounds and stood between 6’4” and 6’5”. After approximately seven weeks of training, Phil lost 25 pounds of mostly fat and posted 255 pounds of lean muscle mass at a weight of 325. This is more muscle than I have ever seen on any other athlete. In testing done by the team, he was equal to, if not superior, to all the other linemen (who weighed around 280) in the 10- and 20-yard dashes and in the agility test. He was so powerful that he was able to leap up onto a three-foot table from a push-up position.
What is a muscle stretch reflex?
A reflex is defined as an involuntary, unlearned, repeatable, automatic reaction to a specific stimulus which does not require input from the brain. The muscle stretch reflex is the most basic reflex pathway in the body and as such, understanding this allows understanding of more complex reflexes.
What is the strength of reflex?
The strength of the reflex can be graded from 0 (no response) to 4+ (clonus) with 2+ (brisk response) being normal.
What is a monosynaptic reflex?
A monosynaptic reflex, such as the knee jerk reflex, is a simple reflex involving only one synapse between the sensory and motor neurone. The pathway starts when the muscle spindle is stretched (caused by the tap stimulus in the knee jerk reflex).
What is the pathway that controls reflexes?
A reflex arc is a neural pathway that controls a reflex. Most sensory neurones have a synapse within the spinal cord, allowing for reflexes to take place without the involvement of the central nervous system (CNS) - speeding up the process. The pathway can be described as a ‘reflex arc’ which is made up of 5 components:
What is the most basic reflex pathway in the body?
The muscle stretch reflex is the most basic reflex pathway in the body and as such, understanding this allows understanding of more complex reflexes. This article shall discuss the components of a reflex arc, the monosynaptic reflex and relevant clinical issues. Reflex Arc Components. A reflex arc is a neural pathway that controls a reflex.
Why is reflex not present?
When testing reflexes it is important to know which spinal root level you are testing. If the reflex is not present it could be due to a problem with the receptor, the spinal cord, the motoneurone, the neuromuscular junction or the muscles.
Which muscle is inhibited in the knee jerk reflex?
The antagonistic muscle is inhibited and the agonist muscle contracts i.e. in the knee jerk reflex the quadriceps contract and the hamstrings relax. The sensitivity of the reflex is regulated by gamma motoneurones – these lead to tightening or relaxing of muscle fibres within the muscle spindle.
How to get your heart rate to drop?
Stretch your body when your muscles are already warm, either after a warmup or at the end of your workout as part of a cool-down routine. Or, you can do a simple stretching routine on its own. Doing stretches after you warm up and before you start a high-intensity activity can cause your heart rate to drop. Make sure your heart rate is elevated ...
How does stretching help your back?
Increases flexibility and range of motion. Regular stretching can increase flexibility and improve your range of motion. Improving your flexibility opens up your body, releasing stress and tension. It also helps to treat and prevent back pain.
How long does it take to stretch a muscle?
Static stretches are held for a set time, which can range from 10 seconds to 3 minutes.
How to be more active?
You’ll feel better mentally and physically, which may inspire you to be more active. Check in with a fitness professional or friend every so often to make sure you’re stretching safely and effectively. Change up your routine from time to time to give your body a chance to get used to different stretches.
How to prevent muscle soreness?
Boosting your blood flow may even start or speed up the recovery process and prevent delayed onset muscle soreness (DOMS). In addition to exercise, include some of these foods in your diet to improve blood flow and circulation.
Why is it important to get blood flowing to your muscles?
Getting the blood flowing to your muscles supports your body’s overall function by reducing stress and delivering oxygen throughout your body. This is especially important if you spend a lot of time sitting or have a sedentary lifestyle.
Why is increasing range of motion important?
Increasing your range of motion allows your body to work efficiently and effectively, so you can:
How to swaddle a baby?
To swaddle your baby, follow these steps: Use a large, thin blanket. Lay the blanket out on a flat surface. Fold one corner in slightly. Gently lay your baby face up on the blanket with their head at the edge of the folded corner. Bring one corner of the blanket across your baby’s body and tuck it snugly beneath them.
Why is my baby not having reflexes?
When to call your doctor. When a baby doesn’t have normal reflexes, it can be sign of potential problems. If the Moro reflex is lacking on one side of your baby’s body, it can be the result of a broken shoulder or a nerve injury. If the reflex is lacking on both sides, it might suggest brain or spinal cord damage.
Why do babies close their fingers?
Your baby will close their fingers around something pressed into their hand, like your finger or a toy. This reflex helps babies develop the skills to intentionally grasp things as they grow.
How to get a baby to sleep on their back?
Fold up the bottom piece of the blanket, leaving room for your baby’s feet and legs to move. Bring the last corner of the blanket across your baby’s body and tuck it beneath them. This will leave only their head and neck exposed. Your swaddled baby should only be laid on their back to sleep.
What is it called when a baby starts crying?
Your baby may or may not cry when they do this. This is an involuntary startle response called the Moro reflex.
Why does my baby suck?
Your baby will automatically begin sucking if something touches the roof of their mouth. Babies do this instinctively for nourishment. But although your baby naturally knows how to suck, it can take some practice to turn it into a skill. If you’re having difficulty breastfeeding, don’t be discouraged.
How do babies pick up their feet?
If you hold your baby upright and let their feet touch a flat surface, they’ll pick up one foot and then the other. It looks as though they’re trying to take steps. This reflex helps babies develop the controlled skill of walking, which they’ll probably start doing around their first birthday.
Overview
Supraspinal control
Supraspinal control of the stretch reflex means the signal travels above the spinal cord before traveling back down to the same segment it entered the spinal cord from. The responses from these pathways are often termed medium or long latency stretch reflexes, because the time course is longer due to distance it needs to travel. The central nervous system can influence the stretch reflex via the gamma motoneurons, which as described above control the sensitivity of t…
Structures
The stretch reflex is accomplished through several different structures. In the muscle, there are muscle spindles, whose extrafusal muscle fibers lie parallel to the muscle and sense changes in length and velocity. The afferent sensory neuron is the structure that carries the signal from the muscle to the spinal cord. It carries this action potential to the dorsal root ganglion of the spinal cord. The efferent motor neuron is the structure that carries the signal from the spinal cord bac…
Examples
A person standing upright begins to lean to one side. The postural muscles that are closely connected to the vertebral column on the opposite side will stretch. The muscle spindles in those muscles will detect this stretching, and the stretched muscles will contract to correct posture.
Other examples (followed by involved spinal nerves) are responses to stretch created by a blow upon a muscle tendon:
Spinal control
Spinal control of the stretch reflex means the signal travels between the muscle and spinal cord. The signal returns to the muscle from the same spinal cord segment as where it entered the spinal cord. This is the shortest distance for a reflex signal to travel, thus creating a fast response. These responses are often referred to short latency stretch reflexes.
Clinical significance
The patellar reflex (knee jerk) is an example of the stretch reflex and it is used to determine the sensitivity of the stretch reflex. Reflexes can be tested as part of a neurological examination, often if there is an injury to the central nervous system. To test the reflex, the muscle should be in a neutral position. The muscle being tested needs to be flexed for the clinician to locate the tendon. After the muscle is relaxed, the clinician strikes the tendon. The response should be contraction …
See also
• Proprioception
• Reflex
External links
• Reflex,+Stretch at the US National Library of Medicine Medical Subject Headings (MeSH)
• "Stretch reflex" at Dorland's Medical Dictionary