More effective stretching, Part 2

Last week we looked at one (of many) methods to make stretching more effective, utilizing a neurological reflex called “reciprocal inhibition” If you missed that one, or need a review, click here

Another way to get muscles to the end range of motion is to utilize a technique called “post isometric relaxation”. Notice I did not say to lengthen the muscle; to actually add sarcomeres to a muscle you would need to use a different technique. Click here to read that post.

Contracting a muscle before stretching is believed to take advantage of a post isomteric inhibition (sometimes called autogenic inhibition), where the muscle is temporarily inhibited from contracting for a period immediately following a isometric contraction. This has been popularized by the PNF stretching techniques, such as “contract hold” or “contract relax” . EMG studies do  jot seem to support this and actually show muscle activation remains the same (1, 2) or increased after contraction (3-6). Perhaps it is due to an increased stretch tolerance (7,8). 

The technique was 1st described by Mitchell, Morgan and Pruzzo in 1979 (9). These gents felt it was important to utilize a maximal contraction (using 75-100% of contractile force) to get to have the effect. It was later shown by Feland and Marin (10) that a more minimal, submaximal contraction of 20-60% accomplished the same thing.  Lewit felt that a less forceful contraction offers the same results, and combined respiratory assists (inspiration facilitates contraction, expiration facilitates relaxation) with this technique (11). Interestingly, there are bilateral increases in range of motion with this type of stretching, indicating a cross over effect (12). Regardless of the mechanism, the phenomenon happens and we can take advantage of it. 

This is how you do it: 

  • Bring the muscle to its end range (maximum length) without stretching, taking up the slack. This should be painless, as this will elicit a different neurological reflex that may actually increase muscle tone. 
  • resist with a minimal isometric contraction (20-60%) and hold for 10 seconds.  You can inspire to enhance the effect.
  • relax and exhale slowly. It is important to wait and feel the relaxation. Stretch through the entire period of the relaxation. You should feel a lengthening of the  muscle.
  • repeat this 3-5 times

This technique can also be used with the force of gravity offering isometric resistance. In a hamstring stretch, you could lean forward while maintaining the lumbar lordosis and allowing the weight of the upper body to provide the stretch. 

Wasn’t that easy? Now you have another tool in your toolbox for yourself or your clients.

The Gait Guys. Giving you useful information and explanations in each and every post.

  1. Magnusson SP, Simonsen EB, Aagaard P, Sorensen H, Kjaer M. A mechanism for altered flexibility in human skeletal muscle. J Physiol. Nov 15 1996;497 (Pt 1):291–298
  2. Cornelius WL. Stretch evoked EMG activity by isometric coontraction and submaximal concentric contraction. Athletic Training. 1983;18:106–109
  3. Condon SM, Hutton RS. Soleus muscle electromyographic activity and ankle dorsiflexion range of motion during four stretching procedures. Phys Ther. Jan 1987;67(1):24–30 
  4. Mitchell UH, Myrer JW, Hopkins JT, Hunter I, Feland JB, Hilton SC. Neurophysiological reflex mechanisms’ lack of contribution to the success of PNF stretches. J Sport Rehabil. 2009;18:343–357 
  5. Youdas JW, Haeflinger KM, Kreun MK, Holloway AM, Kramer CM, Hollman JH. The efficacy of two modified proprioceptive neuromuscular facilitation stretching techniques in subjects with reduced hamstring muscle length. Physiother Theory Pract. May 2010;26(4):240–250 
  6. Osternig LR, Robertson R, Troxel R, Hansen P. Muscle activation during proprioceptive neuromuscular facilitation (PNF) stretching techniques. American journal of physical medicine. Oct 1987;66(5):298–307
  7. Mahieu NN, Cools A, De Wilde B, Boon M, Witvrouw E. Effect of proprioceptive neuromuscular facilitation stretching on the plantar flexor muscle-tendon tissue properties. Scandinavian journal of medicine & science in sports. Aug 2009;19(4):553–560 
  8. Mitchell UH, Myrer JW, Hopkins JT, Hunter I, Feland JB, Hilton SC. Acute stretch perception alteration contributes to the success of the PNF “contract-relax” stretch. J Sport Rehabil. May 2007;16(2):85–92
  9. Mitchell F Jr., Moran PS, Pruzzo NA: An Evaluation of Osteopathic Muscle Energy Procedures. Pruzzo, Valley Park, 1979.  
  10. Feland JB, Marin HN. Effect of submaximal contraction intensity in contract-relax proprioceptive neuromuscular facilitation stretching. Br J Sports Med. Aug 2004;38(4):E18.
  11. Lewit K: Postisometric relaxation in combination with other methods of muscular facilitation and inhibition. Man Med, 1986, 2:101-104.
  12. Markos PD. Ipsilateral and contralateral effects of proprioceptive neuromuscular facilitation techniques on hip motion and electromyographic activity. Phys Ther. Nov 1979;59(11):1366–1373

Do you do manual muscle testing?

Following up on yesterdays post…
We all like to evaluate our patients; hopefully on the table as well as observation while weight bearing. Here is some food for thought.

When your patient or client is lying on the table, do you pay attention to where there head is in space (ie the position of their head)? Why should you care?

Remember our post on facilitation (if not, click here)? That has something to do with it.

Here is the short story. Make sure the head is neutral and midline (lined up between the shoulders), there is good preservation of the cervical curve , with a small pillow supporting the neck, but not altering it’s angle.

The long story involves the vestibular system. It is a part of the nervous system that lives between your ears (literally) and monitors position and velocity of movement of the head. There are three hula hoop type structures called “semicircular canals” (see picture above) that monitor rotational and tilt position and angular acceleration, as well as two other structures, the utricle and saccule, which monitor tilt and linear acceleration. I think you can see where this is going….

The vestibular apparatus (the canals and the utricle and saccule) feed into a part of the brain called the floccular nodular lobe of the cerebellum, which as we are sure you can imagine, have something to do with balance and coordination. This area of the cerebellum feeds back to the vestibular system (actually the vestibular nucleii); which then feed back up to the brain as well as (you guessed it) down the spinal cord and to predominantly the extensor muscles.

So, what do you think happens if we facilitate (or defaciltate) a neuronal pool? We alter outcomes and don’t see a clear picture.

Look at the picture above. Notice the lateral semicicular canals are 30 degrees to the horizontal? If you are lying flat, they are now at 60 degrees. If the head is resting on a pillow and flexed forward 30 degrees, the canals are vertical and rendered inoperable. This could be good (or bad) depending on what muscle groups you are testing.

OK. HEAVY CONCEPT APPROACHING

So if we defacilitate the extensors, what happens to the flexors? Remember reciprocal inhibition (If not click here)? According to the law of reciprocal innervation, the flexors will be MORE FACILITATED. If the extensors are faciltated, they will appear MORE ACTIVE and the flexors LESS ACTIVE.

Wow. All this from head position…The key herer is to know what you are doing, This gait stuff can get pretty complex; but don’t worry. We aren’t going anywhere and are here to teach you.

The Gait Guys . Gait Geeks are the new cool….

Just because a muscle tests weak doesnt mean it needs activated.

To Activate or Not Activate: That is the question…

Just because a muscle tests weak does not mean it can, should or needs to be activated.

Muscles become inhibited for many reasons.  Perhaps it is being forced into a substitution or compensation pattern because the primary motor pattern is not accessible.  Perhaps it is because there is a local inflammatory response (ie injury) near by or within the muscle. Perhaps the muscle is lacking in one or several of its primary tenants, S.E.S. (Skill, Endurance, or Strength). Perhaps the joint(s) that muscle crosses are arthritic, inflamed, damaged, remember that an inflamed joint does not like compression/loading. When a muscle contracts it will increase compression across the joint surfaces. Maybe it is being reciprocally inhibited by it’s antagonist, or does not have appropriate sensory feedback from its mechanoreceptors and is neurologically inhibited. The nervous system is wired with many “faults”, which shut things down. Often times, you need to explore the reason why.

So…What happens if you decide to “activate” the muscle regardless of any of the above, which should have been clearly determined by a clinical examination ?

You very well could be forcing that muscle back on the grid encouraging the muscle to perform in an unsafe or undesirable environment. You may be forcing compressive loading across a joint that is inflamed. You could be forcing compression and shear across a damaged cartilage interface, an osteochondral defect, a ligamentous tear or a combination of the above.  You will also be over riding the nervous systems inherent neuro-protective mechanism and by forcing the muscle to once again activate and work in a faulty movement pattern.  You very likely are reprogramming an unsafe and potentially damaging motor pattern.

Remember, when you “mess around” and over ride neuro-protective inhibition of a motor pattern you reteach a potentially dangerous sensory response telling the joint that the nervous system has been mistaken, that it is actually safe to place load and shear across the joint when in fact it is dangerous. Protective reflexes are there for a reason, to protect you!

We have seen the results of well intentioned or sometimes untrained individuals implementing activation into their clinical practices, coaching, or training.  Without a sound clinical examination to determine the reason for muscle inhibition one is taking a whole pile of warning signs and throwing them to the wind.  Remember, if you force a muscle back into activation despite all of the warning signs and reasons for inhibition, you will get a temporarily stronger muscle. This is not necessarily success.

In fact, what you have done, is enabled your client the ability to once again impart load and shear across a joint(s) and motor chain that was getting clear central nervous system signals to avoid the loading response.  You are essentially forcing a  compensation pattern and we all know where that leads to. 

As clinicians, we take an oath that states: “Primo Non Nocere”, which means “first, do not injure”. Know what you are doing. If you don’t, then get the training or don’t do it.

The Gait Guys. Were are here to help. We are watching. Do us proud and do the right thing.

Just because a muscle tests weak doesnt mean it needs activated.

To Activate or Not Activate: That is the question…

Just because a muscle tests weak does not mean it can, should or needs to be activated.

Muscles become inhibited for many reasons.  Perhaps it is being forced into a substitution or compensation pattern because the primary motor pattern is not accessible.  Perhaps it is because there is a local inflammatory response (ie injury) near by or within the muscle. Perhaps the muscle is lacking in one or several of its primary tenants, S.E.S. (Skill, Endurance, or Strength). Perhaps the joint(s) that muscle crosses are arthritic, inflamed, damaged, remember that an inflamed joint does not like compression/loading. When a muscle contracts it will increase compression across the joint surfaces. Maybe it is being reciprocally inhibited by it’s antagonist, or does not have appropriate sensory feedback from its mechanoreceptors and is neurologically inhibited. The nervous system is wired with many “faults”, which shut things down. Often times, you need to explore the reason why.

So…What happens if you decide to “activate” the muscle regardless of any of the above, which should have been clearly determined by a clinical examination ?

You very well could be forcing that muscle back on the grid encouraging the muscle to perform in an unsafe or undesirable environment. You may be forcing compressive loading across a joint that is inflamed. You could be forcing compression and shear across a damaged cartilage interface, an osteochondral defect, a ligamentous tear or a combination of the above.  You will also be over riding the nervous systems inherent neuro-protective mechanism and by forcing the muscle to once again activate and work in a faulty movement pattern.  You very likely are reprogramming an unsafe and potentially damaging motor pattern.

Remember, when you “mess around” and over ride neuro-protective inhibition of a motor pattern you reteach a potentially dangerous sensory response telling the joint that the nervous system has been mistaken, that it is actually safe to place load and shear across the joint when in fact it is dangerous. Protective reflexes are there for a reason, to protect you!

We have seen the results of well intentioned or sometimes untrained individuals implementing activation into their clinical practices, coaching, or training.  Without a sound clinical examination to determine the reason for muscle inhibition one is taking a whole pile of warning signs and throwing them to the wind.  Remember, if you force a muscle back into activation despite all of the warning signs and reasons for inhibition, you will get a temporarily stronger muscle. This is not necessarily success.

In fact, what you have done, is enabled your client the ability to once again impart load and shear across a joint(s) and motor chain that was getting clear central nervous system signals to avoid the loading response.  You are essentially forcing a  compensation pattern and we all know where that leads to. 

As clinicians, we take an oath that states: “Primo Non Nocere”, which means “first, do not injure”. Know what you are doing. If you don’t, then get the training or don’t do it.

The Gait Guys. Were are here to help. We are watching. Do us proud and do the right thing.

Heads up!

Remember that song “Hold Your Head Up” by the British  band “Argent” in 1972? Ok, maybe not, but the principle is very important to runners and sprinters, so lets talk about it a bit. 

We are wired to maintain our visual axes parallel to the horizon. This involves a series of joint and muscle mechanoreceptors in the neck (for a review of joint mechanoreceptors, click here, muscle mechanoreceptors, click here). These muscle and joint mecanoreceptors receptors, through connections in the midbrain (or mesencephalon as we neuro geeks like to call it) and pons, interact with the vestibular system to keep our head (and our bodies) upright, by firing our extensor muscles.

Berta Bobath, physiotherapist, wrote a great book in 1965 entitled “Abnormal Postural Reflex Activity Caused By Brain Lesions”. In it she describes, among many things, reflexes involving the cervical spine and correlating them to motor function. One of these is the cervical extensor reflex.

To explain this reflex, think of a dog sitting to get a treat. As he looks up while sitting down he has to extend his head, extend his front legs and fires all the axial extensor muscles associated with performing this action. The opposite would also happen, but with the flexors, if he were to bend forward to take a drink; fire front flexors and rear extensors to bend down. There are many more reflexes (tonic neck, cervcio ocular, etc) that could be the subject of another post.

As we have learned from the principle of facilitation (see recent post here), when we fire pur extensors, we fire into the extensor pool, and as a result, ALL extensors get to benefit. The advantage of the receptors in the cervial spine is that the upper four fire DIRECTLY into the flocculo nodular lobe of the cerebellum, and thus have a PROFOUND EFFECT on extensor tone in general.

So, if you want to go faster, why not hold your head up and FIRE YOUR EXTENSORS MORE? Hmmm….Where have you heard this before?

Another magic bullet, courtesy of your built in neurology, we are sharing with you so you and your clients, patients and friends can be better at what they do

The Gait Guys. Stretching your neurology on a daily basis.

The Power of Facilitation: How to supercharge your run.

While running intervals this crisp, cool 19 degree morning, something dawned on me. My left knee was hurting from some patellar tracking issues, but only on initial contact and toe off. I generally run with a midfoot strike. I began concentrating on my feet, lifted and spread my toes and voila! my knee pain instantly improved. Very cool, and that is why I am writing this today. 

Without getting bogged down in the mire of quad/hamstring facilitation patterns, lets look at what happened.

I contracted the long extensors of the toes: the extensor digitorum longus and the extensor hallicus longus; the short extensors of my toes: the extensor digitorum brevis, the extensor hallucis brevis: as well as the dorsal interossei.the peroneus longus, brevis and tertius were probably involved as well.

Do you note a central theme here? They are all extensors. So what, you say. Hmmm… 

Lets think about this from a neurological perspective:

In the nervous system, we have 2 principles called convergence and divergence. Convergence is when many neurons synapse on one (or a group of fewer) neuron(s). It takes information and “simplifies” it, making information processing easier or more streamlined. Divergence is the opposite, where one(or a few) neurons synapse on a larger group. It takes information and makes it more complicated, or offers it more options.

In the spinal cord, motor neurons are arranged in sections or “pools” as we like to call them in the gray matter of the cord. These pools receive afferent information  and perform segmental processing (all the info coming in at that spinal cord segment) before the information travels up to higher centers (like the cerebellum and cortex). One of these pools fires the extensor muscles and another fires the flexor muscles.. 

If someone in the movie theater keeps kicking the back of our seat, after a while, you will say (or do) something to try and get them to stop. You have reached the threshold of your patience. Neurons also have a threshold for firing.  If they don’t reach threshold, they don’t fire; to them it is black and white. Stimuli applied to the neuron either takes them closer to or farther from threshold.  When a stimulus takes them closer to firing, we say they are “facilitating” the neuron. If it affects a “pool” of neurons, then that neuronal pool is facilitated. If that pool of neurons happens to fire extensor muscles, then that “extensor pool” is facilitated.

When I consciously fired my extensor muscles, two things happened: 1. Through divergence, I sent information from my brain (fewer neurons in the cortico spinal pathway) to the motor neuron pools of my extensor muscles (larger groups of motor neurons) facilitating them and bringing them closer to threshold for firing and 2. When my extensor muscles fired, they sent that information (via muscle spindles, golgi tendon organs, joint mechnoreceptors, etc) back to my cerebellum, brain stem and cortex (convergence) to monitor and modulate the response.

When I fired my extensor muscles, I facilitated ALL the neuronal pools of ALL the extensors of the foot and lower kinetic chain. This was enough to create balance between my flexors and extensors and normalize my knee mechanics.

If you have followed us for any amount of time, you know that it is often “all about the extensors” and this post exemplifies that fact.

 Next time you are running, have a consciousness of your extensors. Think about lifting and spreading our toes, or consciously not clenching them. Attempt to dorsiflex your ankles and engage your glutes. It just may make your knees feel better!

The Gait Guys. Facilitating your neuronal pools with each and every post.

All material copyright 2013 The Gait Guys/ The Homunculus Group. All rights reserved. If you rip off our stuff, we will send Lee after you!

Understanding Neuroreceptors: Movement Concepts

For all you inquiring minds out there, here is a question on one of our YOUTUBE videos we though was worth making into a post.

Question: “Dr Waerlop says that GTO’s (golgi tendon organs) inhibit muscle tension and muscle spindle apparatuses (MSAs) increase muscle tension. But then he says to treat the attachments (GTOs) to increase the tension and the bellies (MSA’s) to decrease. Seems counterintuitive. What is the modality of tx, acupuncture? Massage?…..What is your modailty for treating these? And does that modality inhibit those neurosensors or stimulate them?”

Answer: GTO’s are high threshold receptors that actually modulate muscle activity through inhibition  (Ib afferents) and Spindles are lower threshold receptors receptors that modulate overall activity, particualrly length. Think of the GTO’s as responding to tension and the spindles as responding to muscle length. Spindles are more in the belly of the muscle and GTO’s at the musculo tendonous junctions. By treating the origin and insertion of the muscles, you can modulate both, whereas treating the belly of the muscles, seems to affect the spindles more.

By treating the origin and insertion of the muscles, you can modulate both, whereas treating the belly of the muscles, seems to affect the spindles more.

The modality can be manual or acupuncture stimulation of the origin/ insertion of the muscle that tests weak.We find that acupuncture seems to work bestbut manual methods work just fine as well. We believe we are normalizing function, rather than specifically inhibiting or exciting. Like Chinese medicine, we are balancing the Yin and the Yang, creating homeostasis.

The Gait Guys: Making it real. Making it understandable. Making it happen : )