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Last 10 Posts (In reverse order)
Guest Posted: Thursday, January 18, 2018 11:38:26 PM(UTC)
My Wobblies (continued)

At the end of the first summer with discouragingly little aerobatics in my new plane, my wife (who suffers with appreciable chronic pain which is relieved partially, temporarily, by treating trigger points) noticed that two of her books mention dizziness as a symptom of active trigger points in the sternocleidomastoid muscles. I found trigger points in my neck muscles and treated them as described earlier, and resumed flying 10 days later. Over two weeks I moved up to +7 and -5 and used maximum roll acceleration from the third flight onwards without any hint of the wobblies. After continuing to treat my trigger points over the winter, this past season I was able to move up to that g range much more quickly than I could in the Pitts, and I experienced no wobblies over the rest of the summer despite using the maximum roll acceleration routinely. One aspect I have not investigated is the effect of a lot of outside snap rolls because I intend to fly Advanced for at least another year.

My current theory is that roll acceleration is the main source of activation of trigger points in my neck muscles, which are the direct cause of my wobblies. Treating the trigger points daily is sufficient to prevent them from activating to the point that they cause the wobblies. In the Pitts the negative g of outside snap rolls somehow must have amplified the effect of the lazy roll acceleration. The pilot's head is substantially farther from the roll axis in a typical monoplane than in a Pitts, which should amplify the effect of roll acceleration.

This interpretation is supported by an observation that I couldn’t understand when I was flying the Pitts. If I had a moderate case of the wobblies, a six hour drive over rough roads in my Chev S10 (a tall, narrow compact truck) made the symptoms worse, while the same drive in my Corvette, a much harder riding vehicle but lower and wider, had no effect on my wobblies. It now seems significant that the truck snapped my head from side to side much more vigorously than the car did.
Guest Posted: Thursday, January 18, 2018 11:36:11 PM(UTC)
My Wobblies

To explain my enthusiasm for the trigger point hypothesis as the explanation for my wobblies I need to describe my experience with the wobblies in considerable detail.

Mine are somewhat atypical, in that each episode lasts only 1/2 second. At their most severe I get an overpowering sense that I am falling backwards that lasts just long enough for me to initiate a reaction to steady myself and it ends before I actually move, and I do not fall back either. At the mildest the uncertainty in my head orientation increases from the usual 5 degrees to 20 degrees - a strange sensation that seems to come from the center of my head. These momentary bits of disorientation occur only after I move my head in a direction it hasn’t moved for several minutes. I do not get symptoms while flying, probably because I move my head too frequently to allow the stationary time that seems to be necessary.

I first experienced these wobblies while practicing daily for my first Unlimited contest in a Pitts Special. It took two weeks of no flying for the severity of the symptoms to drop to the lowest detectable level, and the frequency from every few minutes to once an hour. I resumed practicing and continued to experience the symptoms at a low level of severity and frequency. Over the next 10 years I learned to pace my flying to keep them from getting up to the most severe level. Every spring I started out at +6 and -3 and gradually increased to -5 over about 20 flights. Despite this conditioning program I still experienced the mild form as soon as I started practicing negative g figures frequently. I suspect that outside snaps were more important than pushes because I did not experience the wobblies while flying Advanced in the same plane. I learned to tolerate the mild form of my wobblies and adjusted my flying schedule whenever I started to get any sense of falling backwards.

I tried the pre-flight neck stretches suggested by Fred DeLacerda, as well as his ideas of immobilizing my head with my chin on my chest during g-loading and lying down after flying. This made no difference that I could detect. I contemplated trying strength training during the winter, but I couldn’t bring myself to do something so boring and unpleasant.

Two years ago I switched to a plane with much greater roll rate and a reclined seating position. I started the usual way at +6 -3g. On the third flight I experimented with using the full roll acceleration of the plane and with inside snaps, and I was hit with moderately severe wobblies. I resumed flying after the symptoms subsided two weeks later and I got exactly the same results - no wobblies until I used the maximal roll acceleration. Out of curiosity I did this again with the same results.
Guest Posted: Thursday, January 18, 2018 11:33:45 PM(UTC)
Treating Trigger Points in the Neck

There are several different treatments for trigger points, but the only practical method of self-treatment is massage. You simply stroke across the trigger point using direct pressure (or a pinch) that causes roughly half the maximal pain intensity that extreme pressure causes. It’s probably best to stroke in one direction only, and there is some theoretical justification for stroking towards the heart. Some therapists recommend very mild exercise to mobilize the affected muscles prior to massage and gentle stretching after massage, and I chose to do both.

For gentle exercise I tilted my head towards the affected muscle against light resistance from my hand, ten times. For massage I settled on 17 strokes, as more than 20 seemed to cause the trigger point to become more sensitive. Stretching after massage, which was the most time-consuming part of treatment, followed the usual physiotherapists advice. I stretched each muscle by tilting my head gradually until reaching some resistance or pain, stopping until that abated (typically ten seconds), then continuing for a total of 30 seconds. I worked around my neck and stretched each muscle three times.

I treated each trigger point twice a day until they because noticeably less sensitive to pressure, which took 10 days, then resumed flying aerobatics and found my wobblies were gone. I’ve continued to massage the affected parts of my neck muscles once a day since my discovery of the trigger points, and I’ve had no recurrence of my wobblies. In that time, occasionally every trigger point abruptly became more sensitive to pressure and improved over several days of massage, including during the winter when I wasn’t flying, probably because my poor posture continually reactivates them. However, in no case has any trigger point become as sensitive to pressure as they were when I first discovered them.
Guest Posted: Thursday, January 18, 2018 11:27:31 PM(UTC)
Detecting Trigger Points

The defining characteristic of a trigger point is moderately intense pain which occurs when pressure is applied directly to the affected portion of muscle, which cannot be explained by a recent injury. For trigger points that are actively causing symptoms this takes far less pressure than is required to cause pain or discomfort in an unaffected portion of muscle. The pressure must be applied accurately, as missing the trigger point by as little as a half inch may not provoke any pain. Normally the pain is perceived within the portion of muscle being pressed, but sometimes the pressure also elicits the remote symptoms that the trigger point is responsible for. When trigger points are first discovered, it is commonplace for their existence to be a surprise.

It is fairly easy to test yourself for trigger points in the sternocleidomastoid muscles. A search on Google will pull up diagrams to show you where to probe. To calibrate your fingers, press on or pinch a small muscle in your forearm hard enough to cause a bit of discomfort, but not actual pain. Use half that force on your neck muscles. Since trigger points are small, it’s best to stroke along about an inch of muscle at a time. If you hit an active trigger point, you will feel fairly significant pain. One thing to be careful of is applying pressure anywhere you can feel a pulse, as you don’t want to press hard on the carotid artery. Where the sternocleidomastoid muscle passes over the carotid, it’s better to tilt your head to relax the muscle and pinch it between your thumb and fingers. Or, it may be easier for you to pinch the muscle if you turn your head to the side to stretch the muscle and lift it off the underlying structures.

I was astonished to find a dozen or so trigger points in all sections of my sternocleidomastoid muscles. I also found trigger points in the trapezius muscles, which were implicated in causing dizziness in one report I found, as well as several trigger points in other muscles in the back and sides of my neck. (I had no neck pain of any sort at the time I found these exceptionally tender spots in my neck muscles.) Just once, when I pressed on a trigger point in the sternocleidomastoid for the first time I induced a mild form of my wobblies.

Subsequent reading led me to the speculation that these trigger points are the consequence of chronic misuse of my neck muscles as a result of lifelong improper posture. I treated all of them.
Guest Posted: Thursday, January 18, 2018 11:19:31 PM(UTC)
I would like to relate my experience with curing the wobblies, as it might help others struggling with the same problem. If you decide to assess for yourself whether you might have the same cause of your wobblies, it will take you less time than it will take to read this post. My experience might be relevant to only a subset of acro pilots because it is likely that there are multiple causes of the wobblies.

The Hypothesis

I propose a reinterpretation of the idea that the wobblies can be caused by problems in the neck muscles, which was suggested by Fred DeLacerda in an article in Sport Aerobatics (October 2000). He noted that injuries to the neck muscles can cause vertigo in many other situations, and he speculated that aerobatics can cause similar injuries. In cases where neck muscles are the origin of the wobblies, I think the cause is not injuries to the neck muscles, but trigger points in those muscles.

This is an important distinction for several reasons. First, the treatment proposed by Fred, stretching of the neck muscles prior to flying aerobatics, is a minor part of the treatment for trigger points but by itself it is insufficient and might be counterproductive. Second, the IAC Wobblies Study found a reduced incidence of the wobblies among pilots who do frequent strength training (Sport Aerobatics, February 2003, complete report January 2004). Fred wrote a commentary on that study (Sport Aerobatics June 2004) in which he appeared to regard this as a vindication of his theory, but it wasn’t clear whether he regarded strength training as only a method of preventing the wobblies or also as a treatment. If the actual problem is trigger points, it is absolutely the wrong thing to do strength training as a treatment for the wobblies. Third, most people with the wobblies have not had a recent neck injury which might be aggravated by the stresses of aerobatics. Finally, Fred’s idea isn’t plausible to me. It is possible to move the head in any direction without excessive effort during the +6 and -5g aerobatics that causes my wobblies. I cannot see how stresses on the neck muscles during aerobatics could injure them sufficiently to cause the wobblies.

Trigger points are small tender parts of muscles which cannot be explained by recent injury. While the science of trigger points is meagre, it is speculated that they are small regions of persistent contraction. How they arise is unknown. They appear to cause a variety of symptoms, for reasons that are not understood. The most frequent is pain which often is perceived at some distance from the trigger point. Other symptoms include reduced range of motion and numbness, and dizziness if the trigger points are within the sternocleidomastoid muscles of the neck.

It is generally accepted in the trigger point literature that trigger points can be activated by stresses that do not damage muscle fibres. Thus it seems possible that the stresses of aerobatics might activate latent trigger points in key neck muscles. Once activated they might cause errors in positional information sent to the brain which would cause dizziness just as injuries to neck muscles may cause dizziness.

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