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Why You Should Be Using Biofeedback in Rehabilitation

This week’s article is an excellent guest post from my friend Russ Paine, PT, discussing why and how we should be using biofeedback in our rehabilitation patients.  Russ and I are both big fans of biofeedback but unfortunately it’s fallen out of favor because insurance companies don’t reimburse it. But that doesn’t mean it’s not effective.  And now, there’s a new biofeedback device, the mTrigger, that uses an app on your phone that is amazingly easy to use and affordable. I think this is going to be a real game changer.  And mTrigger was nice enough to offer my readers 10% off! More details below, but check out the article and our video first!


Why You Should Be Using Biofeedback in Rehabilitation

I have been involved in the evaluation and treatment of sports medicine injuries for 33 years.  I have been very fortunate to have a “true” sports medicine practice that predominantly includes professional, college, high school, amateur, and aging athletes.  Having this type of clientele has forced me to explore and pursue restoring full function in the timeliest manner, being very careful to not cause harm using an aggressive approach.  

I believe that one of the secrets to having successful return to sports with minimal adverse effects is fully restoring muscle function.  

Although many aspects of our field have seen excellent advancements and growth, we continue to combat one of the most difficult challenges following injury and surgery, muscle atrophy and weakness.  

Restoration of muscle function should not only be measured by muscle force output and scores obtained on functional tests, but neurological function. In my practice, establishing normal neurological function following knee surgery is goal number one for our patients’ initial step on the path toward successful return to function.  

 

The Use of Biofeedback in Rehabilitation

So how do I do this?  The use of biofeedback is my preferential method of attacking the neurological deficit following surgery or injury.  

New advances in biofeedback devices have recently allowed the ability to provide a general assessment of the patients’ EMG neurological status. The subjects’ ability to fire the inhibited muscle may now be conveniently measured by recording EMG activity of the involved extremity and comparing this to the opposite normally functioning muscle group.

The primary rationale for use of biofeedback is the belief that the patient should begin use their own “electrical system” as soon as possible through volitional contraction.  

The concept known as order of recruitment lends support to the use of biofeedback to enhance volitional contraction.  This order is based on the size principle. Heinemann’s size principle states that under load, motor units are recruited from smallest to largest. In practice, this means that slow-twitch, low-force, fatigue-resistant muscle fibers are activated before fast-twitch, high-force, less fatigue-resistant muscle fibers.  

When using a biofeedback device, the clinician sets the goal for the inhibited muscle so that a strong voluntary effort is required by the patent for each contraction.  This is visible to the patient and forces a strong contraction to reach the pre-set goal. I believe that voluntary contraction using biofeedback produces the greatest results in restoring muscle function early.

 

Biofeedback or Neuromuscular Stimulation?

Neuromuscular electrical muscle stimulation (NMES) is often used to stimulate muscle contraction.  There is a vast amount of literature supporting NMES for use during rehabilitation. Until recently, NMES has been a reimbursable modality, thus there was much financial support to research its’ effectiveness.  

Biofeedback has not been reimbursable and that may have had an effect on the comparative lack of literature.  One article from Draper and Ballard supports the use of biofeedback over NMES.  This article compared the two modalities during ACL rehabilitation.  After 6 weeks, the biofeedback group was shown to provide greater quadriceps isometric muscle strength than NMES treated group.

I believe in the use of NMES if a patient is unable to make any voluntary contraction, which sometimes happens following ACL reconstruction surgery.  But, once a patient is able to produce a voluntary contraction, detected by the biofeedback, we immediately switch the patient to biofeedback.

When using NMES, all nerve fibers are stimulated simultaneously.  This, in my opinion, is not as effective as biofeedback because the order of recruitment from small to large diameter nerve fibers is not sequential as is the case with voluntary contraction.  NMES actually recruits the large diameter nerve fibers first because they are more excitable, as large diameter axons have less resistance to firing. Atrophy of muscles has predominate effects on the slow twitch smaller diameter Type I  fibers, so recruiting these muscle fibers is critical to reverse the effects of muscle inhibition and atrophy.

 

How to Use Biofeedback in Rehabilitation

I use biofeedback on virtually every knee patient that has decreased neurological EMG output.  As previously mentioned, we are able to use a new device to provide a side to side assessment of EMG activity.  

This information as also very educational and motivational to the patient as they can see the actual deficit via visual EMG numbers between normal and involved.  

Cycles of 10 seconds on and 10 seconds off are utilized during the 10 minute biofeedback session.  My instructions to the patient for quadriceps re-education are to “tighten your muscle and force your knee straight”.  Progress is continued to be monitored on a weekly basis to measure the change in EMG activity, as shown using the biofeedback application.  

The mTrigger Biofeedback device that we use utilize has an amplifier that sends the measured EMG activity via a Bluetooth signal to an android or IOS device with the appropriately downloaded software application.  

This mTrigger is available for home use as well as clinical use.  Patient reported motivation using this type of biofeedback product is very high as they can actually visualize their intensity of muscle contraction when performing home exercise programs.  There seems to be an interesting psychological connection between the use of one’s personal smartphone or computer pad and their muscle activity.

Lack of extension of the knee has been shown to have an adverse effect of knee function.  Loss of extension alters the gait pattern and can produce abnormal stresses to the patellofemoral joint.  Due to a lack of quadriceps control many quad inhibited patients will ambulate with a flexed knee gait pattern.  

The use of biofeedback can be used to combat this common malady often associated with post-op care of the knee.  Lacking quad control, patients’ are unable to eccentrically control the knee flexion moment that occurs during single limb balance.  A quad inhibited patient will assume this flexed knee position because they “know” the position of the knee during single limb balance.

This sets up the knee for a co-contracted state and presents as muscle splinting until normal muscle tone and function are restored.  This muscle splinting will continue to exacerbate the lack of extension in the knee. Biofeedback can be very effective at addressing this issue.  

With muscle splinting, we want to teach the patient to relax the hamstring muscle during knee extension stretching, thus negating the effect of a contracting hamstring muscle.  The patient is placed in a prone position, with both patella over the edge of the table. Electrodes are placed over the hamstring muscle. Unlike the inhibited quadriceps muscle where we are trying to elicit a more perfect contraction, the biofeedback unit is now used for relaxation purposes.  As the patient uses the relaxation mode of the unit, and learns to control the overly active hamstring contraction immediate increase in passive knee extension is observed.

This position is maintained for a 10 minute period.  Once the patient has “learned” to control the hamstring over activity, a light weight may be applied for the 10-minute period to produce a low-load long-duration stretch.  Change in knee extension can be measured using heel height difference measurement technique. Dale Daniel described this measurement and showed that 1cm of HHD = 1 degree of flexion contracture.

Note from Mike: That’s a great example of how you would use biofeedback to work reducing muscle activity.  It’s not always used to increase activity. Another way we use it is to use both channels together on 2 different muscle groups.  Imagine doing a bird dog or glute bridge with the pads on the glutes and low back. You would focus on performing the drill with high glute activity and low back activity.  It’s pretty neat.

 

Return to Play

Return to play is a hot topic in rehab right now.  It’s difficult to determine if the athlete is ready to return to sport.  There are many obstacles when assisting your athlete to the ultimate goal of returning to sport with pre-injury level of performance.  

Too often, a shift is made during the rehabilitation process to more functional activities and reduced emphasis on strengthening.  If your patient continues to possess a decreased EMG signal compared to normal side, it will be highly unlikely that they will be able to resume the pre-injury level of function.  

With biofeedback, we have a tool that makes certain that we have completed one of the early critical steps in the process of rehabilitation – restoring and measuring normal neurological function of the inhibited muscle group.  Don’t allow decreased EMG function be one of the obstacles to continue to linger.

 

The mTrigger Biofeedback Device

I thought that was a great article from Russ.  Many don’t even realize how impactful biofeedback can be as it has fallen out of favor.  Here’s a great video from Russ and I demonstrating the mTrigger device and talking about how and why we use biofeedback:

 

As you can see, the new mTrigger device is so simple to use and completely affordable.  That has always been a limitation in biofeedback devices, they were just to clunky and expensive.

If you want to get started using biofeedback, mTrigger was nice enough to offer my readers 10% off their purchase, making this even more affordable.  Click the link below and be sure to use coupon code REINOLD to get your 10% off

 

About the Author

Russ Paine, PT, is known for his experience in sports medicine with special interests in injuries to the knee and shoulder, as well as golfing injuries and conditioning. His client list includes many professional athletes who have sought his expertise to help them recover to their prior level of function. Russ has a long career in sports medicine, having served as rehabilitation consultant to the Houston Astros, Houston Rockets, and NASA. Currently the Director of Sports Medicine Rehabilitation at UT Physicians in Houston, TX, Russ continues to devote his time to research and education while maintaining a busy sports medicine clinical practice.  Russ was inducted into the Sports Physical Therapy Hall of Fame in 2018. As a well-established author and lecturer on topics related to sports medicine, he has lectured at over 500 meetings in the US and abroad. He has published 25 chapters in textbooks and over thirty research articles in peer review journals.

 

 

 

Is Icing an Injury Really Bad for You? What the Science Says

Today’s article is an excellent review of the effects of cryotherapy, or ice, from my good friend Phil Page, PhD, PT, ATC, CSCS, FACSM.  Man, icing an injury sure has taken some heat (see what I did there…) lately on the internet.  There is a HUGE anti-ice movement.  I’m always amazed at how polarizing social media can be, with people screaming their black or white opinion, when in reality much of what we do is in the grey.  I get questions all the time about wether or not icing is good or bad for you, with many people quick to jump to the conclusion that we should not be icing.  Well, let’s find out what the research actually says.  Phil’s the Director of Research & Education with Performance Health, and one of the best at analyzing the research.

 

Is Icing an Injury Really Bad for You?

You’ve probably heard the debate on whether icing is helpful or harmful. You might be strongly on one side or the other, or maybe you aren’t sure which side you’re on because you’ve heard so many different things.

Despite what you might hear from anti-ice gurus that tend to be sensationalized on the Internet, let’s look at the facts and how we got here.

Ice isn’t the bad guy. Yes, we tend to apply ice in some situations that probably doesn’t help and claim we do so for the wrong reasons.  But the bottom line is that there are several benefits to ice, and ice has not been proven to impede the healing process as many claim.

About 30 years ago as a student athletic trainer at LSU, we frequently used ice, following the research of Dr. Ken Knight, who literally wrote the book on cryotherapy. I, as most other athletic trainers, was keenly aware of the mechanism of ice after an acute injury. As a graduate assistant athletic trainer for baseball at Mississippi State, I continued to advocate ice for my pitchers after they threw. Ice was my best friend.

Suddenly, stories came out that icing was bad for pitchers. As a matter of fact, one story back then was that it actually caused bursitis! Knowing a little about pathophysiology, I quickly dismissed that hogwash…  but the gears were in motion against using ice after pitching.

Fast forward to a few years ago. All of a sudden, ice is again demonized, but this time, it’s a vicious attack:

“Icing is wrong.”

“Ice impedes healing.”

“Icing is harmful.”

Say it ain’t so! Wha are we supposed to do?  Those are some bold claims!

The argument against ice tends to center around ice impeding the healing process as an ‘anti-inflammatory.’ Throughout the healing process (injury, inflammation, repair, remodeling), we need each of those stages to occur in order.  As an anti-inflammatory, the question was if ice actually creates an environment that does not allow the tissue to repair itself?  Interestingly, this same argument came out around the same time as people started questioning NSAIDS for the same reason!

Well, one study did get published (Tseng et al. 2013) titled, “Topical Cooling (Icing) Delays Recovery from Eccentric Exercise-Induced Muscle Damage.” The authors found increased signs of muscle damage after applying ice following eccentric exercise compared to a ‘sham’ application (although I’m not sure how you actually can apply ‘sham’ ice).

Bingo. Proof that ice impedes healing!  Right?  Hold on cowboy. That’s not the whole story.

What you didn’t hear about unless you actually read the study was that the authors concluded:

This study does not provide evidence on whether recovery from pitching-induced muscle damage would be slowed down by topical cooling.”

And while the authors found increased biomarkers in the group receiving cold therapy, there was no difference in strength or pain between the groups.  And I won’t even get into the question of adequate power with an n of 11.  You could argue that the study did not have enough subjects to have much clinical relevance.

Yet, ice was under attack again.

In addition, a few review studies of ice after ankle injuries raised more doubt on the practice of “RICE” (Rest, Ice, Compression, Elevation). The conclusion was that the quality of the research was generally poor quality, and the outcomes were inconclusive.

Note the word, “inconclusive” is not the same as “ineffective.”

And many times, effectiveness of icing was measured by the amount of swelling, rather than the actual healing process and return to activity. And while we know that ice doesn’t do much for swelling after the first 48 hours (Cote et al. 1988), modest cooling has been shown to reduce edema in animal studies (Collins 2008, Deal et al. 2002).

Yet, there we were, left to question if icing for recovery or after acute injuries was actually helping or hurting our athletes.  How did we get to this point?

 

The Claims Against Ice are Largely Based on Pseudoscience

The claim that ice is harmful by delaying the healing process is not supported by science. You may have seen bits and pieces of “science” in the false claim, but it’s a play on science that doesn’t give you the full picture or ability to make such a bold statement.  It’s called pseudoscience….statements that appear to be based on the scientific method, but are not.

Icing is not harmful or wrong to use.

You have witnessed a sham. Like the cup-and-ball game. It happens so fast and seems logical, but it’s a mind-trick.  Here are several things to consider.

Confirmation Bias

This is the tendency for us to accept evidence to confirm our own beliefs or theories. If you think ice is bad, you will tend to accept the information that supports your belief.  This makes us feel good because it confirms our prejudice.

False Logic

If inflammation (A) is necessary to get to healing (C), and ice (B) reduces inflammation (A), then ice (B) must reduce healing (C). FALSE. There is no direct evidence that icing reduces the healing process. In contrast, research supports the fact that ice does not impede healing (Vieira Ramos et al. 2016).  Granted, this was a study from an animal model, but who wants to be a human subject to test that theory?

Circumstantial Evidence

Evidence that attempts to prove a fact by connecting a related event or condition to a conclusion, as opposed to direct observation, is considered ‘circumstantial.’ This could be one of the most common ways science is used to incorrectly support claims. The presence of biomarkers in the blood may be an indirect measure of muscle damage, but it does not prove ‘cause-and-effect’. (Remember the DOMS study I referenced above?) Guilt by association is not the same as ‘causation.’ Using surrogate measures to make a definitive conclusion is a slippery slope.

Inconclusive Conclusions

Poor research (or no research) cannot serve as a basis for a conclusion on efficacy, let alone harm. The evidence on applying ice after an acute ankle injury is ‘inconclusive’ based on only a few studies of poor quality (Bleakley et al. 2004; van den Bekerom et al. 2012). There are no studies that applying ice after an ankle injury reduces recovery time (Hubbard et al. 2004). In fact, one study showed that early application of ice (< 36 hours) resulted in significantly faster return to play compared to delayed cryotherapy (Hocutt et al. 1982).

Comparing Apples to Oranges

Equating 2 things that appear similar, but are actually different, is not a fair comparison. Comparing DOMS to the healing process is not an accurate comparison. We know more about soft tissue healing after an injury than we do about the mechanism of DOMS, which is not a true model of an acute injury. Don’t forget, inflammation is not the same thing as swelling and edema!

Selective Science

Unbalanced reporting. Cherry-picking the literature. All signs of pseudoscience. The anti-ice movement has neglected years of research on the mechanism of ice after injury, focusing only on a select few studies that support (but in reality DON’T support) their argument. Dr. Knight explained that ice is not an ‘anti-inflammatory’ per-say (Knight, 1976); rather, it prevents the secondary injury to tissues by dampening the negative physiological effects of widespread inflammation. His position has been supported by other researchers as well (Ho et al. 1994, Merrick et al. 1999). And to top it off, one study quoted against icing (Bleakley et al. 2004) even concluded, “The sooner after injury cryotherapy is initiated, the more beneficial this reduction in metabolism will be.” Hmmm…the anti-ice crowd must have missed that statement.

 

The Benefits of Ice

Ice is not wrong or harmful.  The theory that ice impedes the normal healing response by limiting inflammation is not well documented in the literature. If you have been swayed by this on the internet, I would urge you to try to research this more and scrutinize the literature.  Be careful of what you see on the internet and ALWAYS seek to validate anything yourself.

Ice has plenty of benefits and clinical validation.

Proper application of cryotherapy can reduce secondary injury and reduce edema formation if applied within the first 36 to 48 hours (remember, ice doesn’t reduce swelling after the acute injury phase, and may not play a huge role in inflammation or recovery).  We do know that ice helps reduce pain, spasm, and guarding, allowing more mobility (Barber et al. 1998, Raynor et al. 2005).   More than anything, ice is a convenient and potent pain reliever, so it’s ok to apply ice to ‘chronic’ conditions as a safer pain reliever at any time. In fact, cryotherapy has been shown to decrease the amount of prescription pain medications needed after surgery (Barber et al. 1998, Raynor et al. 2005).

Sure, there are some times that ice is overused or erroneously used fort the wrong reasons, like reducing swelling after 48 hours.  The clinical research may not be conclusive, but there is no direct evidence that ice impedes healing. The argument that ice is ineffective or harmful is based on pseudoscience, and we need to be aware of this tactic.

Just be careful what you read, everyone has a bias.  #StandUp4Ice.

 

Is the Intensity of NMES Important for Strength Gains?

Rotator Cuff NMESNeuromuscular electrical stimulation (NMES) is a common modality used in rehabilitation to help restore function and strength of inhibited muscles.  As our professions continue to grow and expand our goal of restoring “function,” many have moved away from modalities like ultrasound and electrical stimulation, and probably for good reason.  However, I still use NMES frequently in my practice to help kick start my strength recovery after injury or surgery.  I like to superimpose NMES on a muscle that is weak or inhibited to help maximize my gains during both simple isotonic exercises and functional movement patterns.

NMES has bee shown in several studies, too many to cite here, to help restore strength faster than exercise alone following surgeries such as ACL reconstruction and total knee replacements.  Furthermore, I have publish and presented on how I use NMES for the rotator cuff after injury and surgery as well.  It appears that patients that have difficulty activating their muscle have difficulty training their muscles at intensities sufficient enough to promote strength gains.

If you want to learn more about how I use NMES for the shoulder, I have a webinar on this topic at RehabWebinars.com.  I definitely recommend you try this as I can honestly say this is something that I do that produces really good results.

A common question regarding NMES involves the intensity of the stimulation.  How strong of a stimulation should we be trying to achieve?

 

Even a Small Amount of NMES is Effective

In my article in AJSM, we reported that peak force production of external rotation with NMES applied was 22% greater than without NMES.  Furthermore, the increase in peak force production was not significantly different based on the intensity of the stimulation.  Essentially, it didn’t matter how high you turned up the ESTIM, you still saw a nice increase in force production.

Even low thresholds of NMES intensity could result in altered motor unit recruitment and subsequent improvement in muscle function.  This doesn’t mean that a small amount of NMES is best, it just means that if you have a patient that doesn’t tolerate a strong contraction, it is still going to provide some benefit and is worth performing.

 

The More NMES Intensity the Better

A recent study was published in the journal Physical Therapy looking at the relationship between intensity of quadriceps NMES and strength recovery after total knee replacement.  The authors concluded that there is a relationship between NMES intensity and change in torque and muscle activation.  This is similar to past finds by Lynn Snyder-Mackler and her group that have published extensively on NMES.

While it does appear that “the more, the better” may be true, we should also careful consider the amount of discomfort and, if the patient is postoperative, the tissue healing status.  We certainly don’t want to increase the patient’s pain to a level of perceived threat that may cause a negative effect on recovery.  Because we know that even a small amount of NMES is beneficial, I generally use the patient’s comfort level as my guide.  Patients are often apprehensive when receiving NMES for the first time.  As their tissue heals and they become more comfortable, you will naturally be able to raise the NMES intensity to maximize gains.  My comment is always “the more the better, but I would like it to be comfortable.”

NMES

What has your experience been with NMES?  Are you using NMES more or less in recent years, and why?

To learn more about how I use NMES for the shoulder following injury and surgery, check out my webinar at RehabWebinars.com.

 

 

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Low-Level Laser Therapy for the Treatment of Chronic Tendinopathy

I found an interesting article in the American Journal of Sports Medicine on the effects of low-level laser on the treatment of Achilles tendinopathy. I must admit that I am, and have been, an avid user of laser energy. Over the years I have tried at least 5 different light/laser units, ranging from one the size of a closet (that required cool green goggles) to simplistic infrared light therapy. Lately, my laser of choice has been the Vectra Genisys by my friends at Empi and Chattanooga.

Lasers are definitely one of those modalities that are trendy right now. This is actually funny to me as the technology is certainly not new. While many clinicians may think laser treatments are “gimmicks,” I challenge those next time they whip out an ultrasound or TENs unit to show me such overwhelmingly positive documentation of it’s efficacy. To date, there have been more than 2 dozen studies on the use of laser technology on tendinopathies. I can tell you that lasers are gaining huge popularity in professional sports, where everyone is looking for an edge. The problem may arise from the lack of popularity in the USA, and thus the lack of knowledge regarding how best to use this modality, making clinical studies important.

The authors of this study sought to examine the effects of laser treatment in conjunction with standard treatment (including stretching and eccentric exercises) on chronic tendinosis of the Achilles in athletes over an 8 week period. One group performed exercises with laser treatments 2x a week for the first 4 weeks and then 1x a week for the next 4 weeks. Another group performed the same exercises but received a sham laser of the same frequency.

The results of the study overwhelming support the use of the laser for chronic tendinopathies.

The subjects in the laser group showed significantly less pain at the 4, 8, and 12 week marks. Pain was reduced by almost 50%.

Interestingly, the laser group had less pain at 4 weeks than the control group did at 12 weeks. The laser group also had significant less crepitation during palpation, tenderness during palpation, and morning stiffness and also increased their active dorsiflexion range of motion.

Clinical Implications

Laser energy is an effective modality for the treatment of tendonopathies. According to the authors, laser is effective on producing an anti-inflammatory effect and a stimulating effect of the tissue repair process. With more and more studies showing that NSAIDs and steroid injections actually impair the healing of acute injuries, treatments like laser energy should be considered.

The results may be dependent on the settings of your laser. There are many different lasers on the market and I will be the first to say that it can get confusing. The authors of the study made a specific point to mention that they notice the best results with lower power densities. They used a power density of 30 mW/cm2 and a low energy dose of 1.5 J. In laboratory studies with power densities > 50 mW/cm2, fibroblast activity and collagen production have been shown to be inhibited.

By reducing pain, laser energy may also allow a faster return to more aggressive stages of rehabilitation and eventually functional activities. I use laser daily to rehabilitate injuries but also to help repair tissue on my athlete’s “regen days.” My patients have reported subjective improvements, but I truly became a believer when I tried the laser on an open wound. The wound healed faster than any other wound I have treated.

I still believe that we have a lot to learn about the use of laser energy, but we are taking steps in the right direction. Please share your experience with lasers. What model are you using? What injuries have you seen success with laser energy? What settings do you use?