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On the subject of manual muscle work…There is more to it than meets the eye….

Following with our last few posts, here is an article that may seem verbose, but has interesting implications for practitioners who do manual muscle work with their clients. We would invite you to work your way through the entire article, a little at a time, to fully grasp it’s implications.

Plowing through the neurophysiology, here is a synopsis for you:

Tactile and muscle afferent (or sensory) information travels into the dorsal (or posterior) part of the spinal cord called the “dorsal horn”. This “dorsal horn” is divided into 4 layers; 2 superficial and 2 deep. The superficial layers get their info from the A delta and C fibers (cold, warm, light touch and pain) and the deeper layers get their info from the A alpha and A beta fibers (ie: joint, skin and muscle mechanoreceptors).

So what you may say.

The superficial layers are involved with pain and tissue damage modulation, both at the spinal cord level and from descending inhibition from the brain. The deeper layers are involved with apprising the central nervous system about information relating directly to movement (of the skin, joints and muscles).

Information in this deeper layer is much more specific that that entering the more superficial layers. This happens because of 3 reasons:

  1. there are more one to one connections of neurons (30% as opposed to 10%) with the information distributed to many pathways in the CNS, instead of just a dedicated few in the more superficial layers
  2. the connections in the deeper layers are largely unidirectional and 69% are inhibitory connections (ie they modulate output, rather than input)
  3. the connections in the deeper layers use both GABA and Glycine as neurotransmitters (Glycine is a more specific neurotransmitter).

Ok, this is getting long and complex, tell me something useful...

This supports that much of what we do when we do manual therapy on a patient or client is we stimulate inhibitory neurons or interneurons which can either (directly or indirectly)

  1. inhibit a muscle
  2. excite a muscle because we inhibited the inhibitory neuron or interneuron acting on it (you see, 2 negatives can be positive)

So, much of what we do is inhibit muscle function, even though the muscle may be testing stronger. Are we inhibiting the antagonist and thus strengthening the agonist? Are we removing the inhibition of the agonist by inhibiting the inhibitory action on it? Whichever it may be, keep in mind we are probably modulating inhibition, rather than creating excitation.

Semantics? Maybe…But we constantly talk about being specific for a fix, not just cover up the compensation. Is it easier to keep filling up the tire (facilitating) or patching the hole (inhibiting). It’s your call

The Gait Guys. Telling it like it is and shedding light on complex ideas, so you can be all you can be.

link: http://jn.physiology.org/content/99/3/1051

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 : )

Tight ankles ? Here we do a short little video for mom.

Gain strength in the anterior compartment to achieve posterior compartment length. Stretching calf is not enough when the calf is tight due to increased neurologic protective tone, possibly an attempt to protect the ankle mortise joint.
So, if stretching is not the solution, look to increase facilitation and strength of the weaknesses in the other compartments.  You just might feel the tightness melt away without stretching at all !

Spindle responses and golgi tendon organ responses. The more you know about the nervous system the smarter your treatments will be.

The Gait Guys, using the functioning of the  nervous system to get the responses we want.

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The whole is greater than the sum of its parts…

This week in Neuromechanics Weekly, we will explore proprioception and total hip replacements.

You would think proprioception (ie body position awareness) would be impaired in a total hip replacement (THR). Not according to this study (see below) BUT Balance, the dynamic interaction of proprioception and the ability to maintain ourselves upright in the gravitational plane AND GAIT were…

We remember there are 3 systems that keep us upright: vision, the vestibular system and the proprioceptive system (ie joint and muscle mechanoreceptors). A THR would effect mostly the latter, especially in this case, whee they REMOVED the hip capsule (capsulectomy). This, of course, would remove any of the joint mechanoreceptors, but probably not the muscle mechanoreceptors (ie spindles and golgi tendon organs).

Look at the conclusion “Compared with the healthy age- and sex-matched controls, patients with total hip replacement did not have any proprioceptive deficit. Patients required extrasensory input, and there was a delayed motor response. Gait and dynamic balance results also indicated the motor deficit and required a compensatory strategy. Restoration of the postural control in these patients is thus essential.”

So, they required a GREATER amount of sensory input and the response was DELAYED. This leads us to believe that is must be the integration of the systems that is the key.

The whole is greater than the sum of the parts… 

All this information is integrated in the cerebellum. Think about the 4 types of joint mechanoreceptors: Type 1 on the outside of the joint (tonic or respond to small movements); Type 2 on the inside of the joint phasic, or respond to large amplitude movements); Type 3, basically a golgi tendon organ type receptor, and Type 4, pain receptors. All this is taken away and they can still tell you where the limb is in space.

What does that mean? ..It means there are MORE receptors, somewhere, providing this info to the brain. They also required “extra input”. Hmmm…something needed to tell the brain that the action (in this case balance and gait) were happening. What was providing it? Muscle spindles and golgi tendon organs (see last weeks high heels post for more info); the former responds to length change and the latter to tension change.

The whole is greater than the sum of the parts.

Rehab it. Work on motor control strategies. Skill, endurance, strength; in that order. Ivo and Shawn. The Gait Guys. Exploring the literature to bring you the best of the best and help you to help others….better.


Balance and gait in total hip replacement: a pilot study. Nallegowda M, Singh U, Bhan S, Wadhwa S, Handa G, Dwivedi SN.

2003 Sep;82(9):669-77. AM J Phys Med Rehabil

Abstract OBJECTIVE:

Evaluation of balance, gait changes, sexual functions, and activities of daily living in patients with total hip replacement in comparison with healthy subjects.

DESIGN:

A total of 30 patients were included in the study after total hip replacement. Balance was examined using dynamic posturography, and gait evaluation was done clinically. Sexual functions and activities of daily living were also assessed. A total of 30 healthy subjects of comparable age and sex served as a control group.

RESULTS:

Dynamic balance and gait differed significantly in both the groups. Despite capsulectomy, no significant difference was observed on testing proprioception. In the sensory organization tests with difficult tasks, patients needed more sensory input from vision and vestibular sense, despite normal proprioceptive sense. Significant difference was observed for limits of stability, rhythmic weight shifts, and for gait variables other than walking base. Some of the patients had major difficulties with sexual functions and activities of daily living.

CONCLUSIONS:

Compared with the healthy age- and sex-matched controls, patients with total hip replacement did not have any proprioceptive deficit. Patients required extrasensory input, and there was a delayed motor response. Gait and dynamic balance results also indicated the motor deficit and required a compensatory strategy. Restoration of the postural control in these patients is thus essential. Necessary training is required for balance, gait, and activities of daily living, and proper sexual counseling is necessary in postoperative care.

http://www.ncbi.nlm.nih.gov/pubmed/12960908

hip replacement image from: http://www.wpclipart.com

champagne lady from: icr.org