Exploring the Links Between Human Movement, Biomechanics & Gait
How are your hammy’s?
Another tool for you, in addition to making sure the gluten are on line, to improve ankle rocker and hip extension.
“This study concludes that neural mobilization techniques are a useful adjunct to static stretching, without any risk of adverse events or injuries. Athletes or trainers can consider using one or both types of neural mobilization techniques to enhance muscular flexibility. Dosage of the neural mobilization as well as the proposed working mechanism behind the increase in hamstring flexibility can be found in the full text of the article.”
Phys Ther Sport. 2016 Jan;17:30-7. doi: 10.1016/j.ptsp.2015.03.003. Epub 2015 Mar 17. Short term effectiveness of neural sliders and neural tensioners as an adjunct to static stretching of hamstrings on knee extension angle in healthy individuals: A randomized controlled trial. Sharma S, Balthillaya G2, Rao R, Mani R .
Do you treat runners? Do you treat folks with knee pain? Patellar tracking issues? Do you treat the quadriceps? Do you realize that the vastus lateralis, in closed chain, is actually an INTERNAL rotator of the thigh (not a typo), and many folks have a loss of internal rotation of the hip? Do you give them “IT band stretches” to perform?
In this short video, Dr Ivo demonstrates some needling techniques for the quads and offers some (entertaining) clinical commentary on the IT band. A definite view for those of you who have needling in their clinical tool box.
We often think of neurological reasons (increased facilitation of the agonist, decreased reciprocal inhibition of the antagonist, increase gamma drive, etc), but how about the series elastic element (ie the connective tissue)? Or perhaps the sarcomere (individual contractile unit of the muscle)? How can we fix that? It is easier than you thought!
An oldie but a goodie. A great FREE FULL TEXT paper on sarcomere loss and how to prevent it. Yep, would you have guessed static stretching? Yes, this study was on mice and it seems plausible that it would be applicable to humans as well.
“When muscle is immobilised in a shortened position there is both a reduction in muscle fibre length due to a loss of serial sarcomeres and a remodelling of the intramuscular connective tissue, leading to increased muscle stiffness. Such changes are likely to produce many of the muscle contractures seen by clinicians, who find that such muscles cannot be passively extended to the full length, which normal joint motion should allow, without the production of muscle pain or injury.
…These experiments show that in addition to preventing the remodelling of the intramuscular connective tissue component daily periods of stretch of ½ h or more also prevent the loss ofserial sarcomeres which occurs in mouse soleus muscles immobilised in the shortened position.”
The last few weeks , we have been talking about techniques to improve your (or your clients) stretching experience. 1st, we talked about reciprocal inhibition here. Next we talked about post isometric inhibition here. The we spoke about the symmetrical tonic neck reflex (response) here. If there is a symmetrical tonic neck reflex, then there must be an asymmetrical one as well, eh? That is the topic of todays discussion.
The asymmetrical tonic neck reflex was 1st described by Magnus and de Kleyn in 1912 (1). Like in the pictures above, when the head is rotated to one side, there is ipsilateral extension of the upper and lower extremity on that side, and flexion of the contralateral (the side AWAY from where you are rotating) upper and lower extremity. Take a few minutes to see the subtleness of the reflex in the pictures above. Now think about how this occurs in your clients/patients. The reflex is everywhere!
The reflex persists into adulthood (2) and is modulated by both eye movement and muscular activity (3). When there is neurological compromise, the reflex can be more prevalent, and it seems to arise from the joint mechanoreceptors in the neck and its connection to the reticular formation of the brainstem (4). It may modulate blood flow and cardiovascular activity as well (5).
So, how can we take advantage of this? We could follow in the footsteps of Berta Bobath (6) and incorporate these into our rehabilitation programs, which we have done, quite successfully. But rather than read a whole book, lets talk about how you could incorporate this into your stretching program.
Let’s say you want to stretch the right hamstring:
actively rotating the head to the right (see reference 3) facilitates the right tricep and right quadricep AND facilitates the left bicep and left hamstring
through reciprocal inhibition, this would inhibit the right bicep and hamstring AND left tricep and left quadricep
To get a little more out of the stretch, you could actively contract the right tricep and quadricep (MORE reciprocal inhibition), amplifying the effect
We encourage you to try this, both on yourself and your clients. It really works!
Wow, isn’t neurology cool? And you thought it was only for geeks!
The Gait Guys. Giving you info you can use in a practical manner, each and every post. Be a geek. Spread the word.
Before we talk about this next one, we need to give you a little background (neurologically speaking).
Take a look at the picture above and note the posturing of the baby in the 2 positions. These neurological reflexes (or postures) are called symmetrical tonic neck reflexes or responses (STNR’s for short) and were described in animals and men by Magnus and de Kleyn in 1912 (1). This work was later studied and reported by by Arthur Simons in 1916 (2) and later by Francis Walshe in 1923 (3). These were later made popular by Berta and Karl Bobath in the 70’s (who studied Walshes work), whom they are often attributed to (4).
You next question is “Do these persist into healthy adulthood”? and the answer is a resounding YES (5).
Take a look at the picture above again and note the following:
When the neck is flexed, the fore limbs flex (and the muscles facilitating that, bicep, brachialis, anterior deltoid are contracting) and the hind limbs are extending (relatively), with the glutes maximus, quadriceps, foot dorsiflexors contracting.
Note that when the head is extended, the forelimbs are extended and the hind limbs flexed. Think about the muscles involved. Upper extremity tricep, anconeus, posterior deltoid, lower back extensors, hamstrings and foot plantar flexors facilitated.
The reflex is based on the mechanoreceptors in the neck articulations and muscles and are frequently used by us and many others in the rehabilitation field. Generally speaking, looking up facilitates things which make you extend above T12, and flex below T12. Looking down facilitates flexion above T12 and extension below.
We would encourage you at this point to “assume” these positions and feel the muscles which are active and at rest.
So, how can we take advantage of these while stretching?
Think about your head position:
If you are standing up and hinging at the hips to stretch your hamstrings (notice we did not say “bent at the waist”; there is a BIG difference in shear forces applied to your lumbar spine) you would probably want your neck bent forward, as this would fire your quads which would in turn ALSO inhibit your hamstrings, in addition to the STNR inhibiting the hamstring.
If you were in a hip flexor stretch position, you would want you head up, looking at the ceiling to take advantage of the reflex.
We are confident you can think of many more applications of this reflex and trust that you will, as it can apply to both upper and lower extremity stretches. Just remember that this reflex is symmetrical and will affect BOTH sides. Of course, there are reflexes that only effect things unilaterally, but that is the subject of another post.
The Gait Guys. Helping make you better at what you do for yourself and others and assisting you on using the neurology that God gave you.
Simons A (1923) Kopfhaltung and Muskeltonus. Ges.Z. Neurol.Psychiatr. 80: 499-549.
Walshe FMR (1923) On certain or postural reflexes in hemiplegia, with special reference to the so-called “associated movements.” Brain 46: 1-37.
Janet M. Howle . Symmetrical Tonic Neck Reflex in Neuro-developmental Treatment Approach: Theoretical Foundations and Principles of Clinical Practice. NeuroDevelopmental Treatment, 2002 p 341 ISBN 0972461507, 9780972461504
While I was making linguine and clam sauce for my family, one of my favorite foods that I haven’t had in quite some time( and listening to Dream Theater of course) I was thinking about this post. Then I remembered about voice recognition on my iMac. Talk about multitasking!
What do you agree that stretching is good or not, you or your client still may decide to do so possibly because of the “feel good” component. Make sure to see this post here on “feel good” part from a few weeks ago.
If you do decide to stretch, make sure you take advantage of you or your clients neurology. There are many ways to do this.One way we will discuss today is taking advantage of what we call myotatic reflex.
The myotatic reflex is a simple reflex arc. The reflex begins at the receptor in the muscle (blue neuron above) : the muscle spindles (nuclear bag or nuclear chain fibers). This sensory (afferent) information then travels up the peripheral nerve to the dorsal horn of the spinal cord where it enters and synapses in the ventral horn on an alpha motor neuron. The motor neuron (efferent) leaves the ventral horn and travels back down the peripheral nerve to the contractile portion of the myfibrils (muscle fiber) from which the the sensory (afferent) signal came (red neuron above). This causes the muscle to contract. Think of a simple reflex when somebody taps a reflex hammer on your tendon. This causes the muscle to contract and your limb moves.
Nuclear bag and nuclear chain fibers detect length or stretch in a the muscle whereas Golgi Tendon organs tension. We have discussed this in other posts here. With this in mind, slow stretch of a muscle causes it to contract more, through the muscle spindle mechanism.
Another reflex that we should be familiar with is called reciprocal inhibition. It states simply that when one muscle (the agonist) contracts it’s antagonist is inhibited (green neuron above). You can find more on reciprocal inhibition here.
Take advantage of both of these reflexes? Try this:
do a calf stretch like this: put your foot in dorsiflexion, foot resting on the side of the doorframe.
Keep your leg straight.
Grab the the door frame with your armsand slowly draw your stomach toward the door frame.
Feel the stretch in your calf; this is a slow stretch. Can you feel the increased tension in your calf? You could fatigue this reflex if you stretched long enough. If you did, then the muscle would be difficult to activate. This is one of the reasons stretching seems to inhibit performance.
Now for an added stretch, dorsiflex your toes and try to bring your foot upward. Did you notice how you can get more stretch your calf and increased length? This is reciprocal inhibition at work!
There you have it, one neurological tool of many to give you increased length.The next time you are statically stretching, take advantage of these reflexes to make it more effective.
The Gait Guys. Teaching you more about anatomy, physiology, and neurology with each and every post.
We get a lot of interest in our posts on stretching. Seems like this is a pretty hot subject and there is a lot of debate as to whether it is injury preventative or not. Are you trying to physically lengthen the muscle or are you trying to merely bring it to its physiological limit? There’s a big difference in what you need to do to accomplish each of these goals. Lets take a look at each, but 1st we need to understand a little about muscles and muscle physiology.
Muscles are composed of small individual units called sarcomeres. Inside of these “sarcomeres” there are interdigitating fibers of actin and myosin (proteins) which interact with one another like a ratchet when a muscle contracts. Sarcomeres can be of various lengths, depending on the muscle, and are linked and together from one end of the muscle to the other. When a muscle contracts concentrically (the muscle shortening while contracting) the ends of the sarcomere (called Z lines or Z discs) are drawn together, shortening the muscle fiber over all (see the picture above).
Signals are sent from the brain (actually the precentral gyrus of the cerebral cortex areas 4, 4s and 6) down the corticospinal tract to the spinal cord to synapse on motor neurons there. These motor neurons (alpha motor neurons) then travel through peripheral nerves to the muscles to cause them to contract (see picture above).
The resting length of the muscle is dependent upon two factors: The physical length of the muscle 2. The “tone” of the muscle in question.
The physical length of the muscle is determined by the length of the sarcomeres and the number of them in the muscle. The “tone” of the muscle determined by an interplay of neurological factors and the feedback loops between the sensory (afferent) receptors in the muscle (Ia afferents, muscle spindles, Golgi tendon organs etc.), relays in the cerebellum and basal ganglia as well as input from the cerebral cortex.
If you’re trying to “physically lengthen” a muscle, then you will need to actually add sarcomeres to the muscle. Research shows that in order to do this with static stretching it must be done 20 to 30 minutes per day per muscle.
If you were trying to “bring a muscle to its physiological limit” there are many stretching methods to accomplish this. Pick your favorite whether it be a static stretch, contract/ relax, post isometric relaxation etc. and you’ll probably be able to find a paper to support your position.
Remember with both not to ignore neurological reflexes (see above). Muscle spindle loops are designed to provide feedback to the central nervous system about muscle length and tension. Generally speaking, slow stretch activates the Ia afferent loop which causes causes physiological contraction of the muscle (this is one of the reasons you do not want to do slow, steady stretch on a muscle in spasm). This “contraction” can be fatigued overtime, causing the muscle to be lengthened to it’s physiological limit. Do this for an extended period of time (20-30 mins per day) and you will physically add sarcomeres to the muscle.
Next time you are stretching, or you were having a client/patient stretch, think about what it is that you’re actually trying to accomplish because there is a difference.
We are and remain The Gait Guys. Bald, good-looking, and above-average intelligence. Spreading gait literacy with each post we publish.
thanks to scienceblogs.com for the corticospinal tract image
We are sure you have read many articles, some written by us, about the good the bad and the ugly about stretching.Regardless of how you slice the cake, we think we can all agree that stretching “feels” good. The question of course is “Why?”
Like it or not, it all boils down to neurology. Our good old friends, the Ia afferents are at least partially responsible, along with the tactile receptors, like Pacinian corpuscles, Merkel’s discs, Golgi tendon organs, probably all the joint mechanoreceptors and well as a few free nerve endings. We have some reviews we have written of these found here, and here and here.
What do all of these have in common? Besides being peripheral receptors. They all pass through the thalamus at some point (all sensation EXCEPT smell, pass through the thalamus) and the information all ends up somewhere in the cortex (parietal lobe to tell you where you are stretching, frontal lobe to help you to move things, insular lobe to tell you if it feels good, maybe the temporal lobe so you remember it, and hear all those great pops and noises and possibly the occipital lobe, so you can see what you are stretching.
The basic (VERY basic) pathways are:Peripheral receptor-peripheral nerve-spinal cord-brainstem-thalamus-cortex; we will call this the “conscious” pathway: and peripheral receptor-peripheral nerve-spinal cord-brainstem-cerebellum- cortex; we will call this the “unconscious” pathway.
Of course, the two BASIC pathways cross paths and communicate with one another, so not only can you “feel” the stretch with the conscious pathway but also know “how much” you are stretching through the unconscious pathway. The emotional component is related through the insular lobe (with relays from the conscious and unconscious pathways along with collaterals from the temporal lobe to compare it with past stretching experiences) to the cingulate gyrus and limbic cortex,where stretching is “truly appreciated”.
As we can see, there is an interplay between the different pathways and having “all systems go” for us to truly appreciate stretching from all perspectives; dysfunction in one system (due to a problem, compensation, injury, etc) can ruin the “stretching experience”.
Hopefully we have stretched your appreciation (and knowledge base) to understand more about the kinesthetic aspect of stretching. We are not telling you to stretch, or not to stretch, merely offering a reason as to why we seem to like it.
richies77 asked a questionHi, Incredible source of information. I have severe arthritis in the 2nd toe of my left foot. I have very little dorsiflexion and this has caused my hip flexor to become chronically, extremely tight. This has twisted my entire spine and made me pretty much disabled. I’ve been offered orthotics and perhaps rocker shoes but do you think surgery is the only way to bring back correct balance to my spine? Does anything else actually work? Thank you!