September 2014

Internal vs external focus: Effects on motor learning

9rehab-iStock14319877A growing body of research is demonstrating that the focus of actions or movements is critical to how well athletes and patients respond to feedback from instructors or clinicians, and one of the central issues is the distinction between internal focus and external focus.

By Cary Groner

The conundrum is familiar to athletic trainers, physical therapists, and others: How do you most effectively teach skills, optimize performance, and address gait and movement issues? If the approach isn’t right, problems involving biomechanics can take longer to fix than they need to. They can even get worse.

Professional football kickers in slumps begin paying close attention to their mechanics and often get less accurate instead of better, for example. Golfers with the yips, ditto. Dancers, faced with a complex series of choreographed moves, become so paralyzed they can barely pirouette.

And that’s just the performance end of the spectrum. Similar issues can affect those undergoing rehabilitation or physical therapy—say, for knee osteoarthritis (OA) or patellofemoral pain (PFP). How a clinician presents rehab and retraining—not just the regimen itself—turns out to have marked effects on outcomes.

“This is a hot topic in motor learning; everyone is racing to figure out the best and most efficient way to give feedback,” said Gregory Myer, PhD, director of the Human Performance Laboratory at Cincinnati Children’s Hospital Medical Center.

Focus

A growing body of research is demonstrating that the focus of actions or movements is critical to how well athletes and patients respond to feedback, and central to that is the balance between internal and external focus.

Simply put, in internal focus the individual’s attention is drawn to the body part in question. To a young female basketball player whose landing mechanics put her at risk for anterior cruciate ligament (ACL) injury, one trainer might say, “Spread your knees as wide as possible when you land.”

In external focus, by contrast, the woman may perform essentially the same action, but with a focus beyond the body. In other words, the trainer might say, “Try to bring your knees as close to the outside walls as possible when you land.”

Doesn’t sound like it would make much difference, does it? But there’s growing consensus that it does.

9rehab-iStock39053400“The idea with external focus is to set up a goal,” Myer said. “That’s why we think it might be more suitable for the acquisition and control of complex motor skills.”

Research increasingly supports the view that external focus affects motor learning by directing the attention to the outcomes of movements instead of the movements themselves.1 The goal is to make actions more automatic and reduce conscious control; and although the mechanism by which this takes place remains murky, internal focus triggers neural activity in the self-system (the collection of drives and responses relating to self-perception) and thereby degrades performance, according to Gabrielle Wulf, PhD.1 In one way, of course, this is intuitive: if you’ve ever had a coach yell at you to get out of your head and just play, this is partly what he was talking about.

The effect has been documented across a range of sports and rehab activities. In a literature review and analysis published last year in the International Review of Sport and Exercise Physiology, Wulf delineated the extent to which research supports the efficacy of externally focused actions.1

“In my review I found no exception to the rule that external-focus instructions or feedback result in more effective and efficient performance or learning than those inducing an internal focus,” she told LER.

A professor in the Department of Kinesiology and Nutrition Sciences at the University of Nevada–Las Vegas, Wulf added that, in the few studies that failed to show benefits of externally focused feedback, there were usually either methodological limitations or an emphasis on relatively simple tasks that were already largely automatic.

“The more complex or challenging the task, the greater the advantages of adopting an external focus,” she continued. “It’s been shown to promote automatic movement control and enhancements in all aspects of performance, including movement effectiveness [balance or accuracy] and efficiency [force production, speed, and endurance].”

In her review, Wulf found that the advantages of externally focused techniques applied to a host of endeavors. In terms of movement effectiveness, these included balance exercises, golf, tennis, throwing, ball kicking, juggling, and gymnastics. In efficiency, studies reported benefits in isometric force production, weightlifting, track-and-field activities, swimming, rowing, and kayaking. They also applied to a range of skill levels and ages.

In one study,2 for example, researchers split novice golfers into two groups. While hitting the ball, one group focused on shifting weight to the forward foot (internal focus), whereas the other group focused on pushing against the ground with that foot (external focus). It sounds like a fine distinction, but those in the second group outperformed the first for a variety of outcomes, including greater carry distance of the ball.

Wulf also clarified that in sports such as basketball, darts, volleyball, and soccer, wording instructions to direct the player’s attention to the anticipated trajectory of the object leads to increased movement accuracy, versus instructions that direct attention to the body part involved, such as the hand or foot.3

Feedback and learning

In both athletics and rehabilitation, experts draw a distinction between performance (the phase when focus instructions are given in real time) and learning (a more permanent change in the ability to perform a skill due to the repetition of these instructed activities).1 This difference helps elucidate the ways in which methods of focus affect behavior.

“For complex, real-life tasks, real-time feedback can enhance learning, particularly when it is interpreted as representing an external movement effect, such as the movements of a balance platform—an external focus—versus the movement of the feet—an internal focus,” Wulf said.

She added, however, that in the artificial environment of the laboratory, individuals’ dependence on real-time feedback can actually impede learning. Many clinicians have noticed the same thing, and as a result have developed strategies to wean patients from real-time feedback so their learning improves and they become self-sufficient sooner. The approach is called “faded feedback,” and it has been applied in a variety of settings.

Occasionally, however, this trend has muddied the distinctions between feedback types, because such clinicians may describe a need to progress from dependence on external feedback (eg, watching a video representation of their stride during gait retraining) to a more internally focused, self-sustaining approach. The problem is at least partly semantic, because it appears that what they’re describing is a shift from effortful activity to one that is more automatic as a result of the learning process. Automaticity, as Wulf points out in her papers, is an important goal; the confusion arises when “internalized” is used as a synonym for “automatic.” This has been common usage for a long time, but internalized feedback is different than internally focused feedback, which involves acute self-examination and is anything but automatic.

Differences of opinion about the relative value of internally and externally focused feedback aren’t all semantic, however. Some clinicians, while acknowledging the value of the latter, disagree that it’s a panacea.

“I don’t think we’re ready to abandon internally focused feedback,” said Greg Myer. “There are cases in which you have to break down complex tasks to identify the specific cause of a problem.”

Richard Willy, PT, PhD, an assistant professor in the Department of Physical Therapy at East Carolina University in Greenville, agreed.

“There is a lot of evidence that externally focused feedback is more conducive to motor learning,” he said, “but some articles4 have found that internal focus in novices can be more beneficial.”

Willy, who touched on the subject as applied to retraining injured runners in a 2013 article for LER,5 typically recommends that, if a patient is having trouble with a novel task, they start with an internal focus, then transition as quickly as possible to external focus once they’ve mastered the basics.

“For example, consider a female runner with patellofemoral pain, who has that classic mechanism of medial-collapse mechanics, but who has a hard time activating her gluteus medius and maximus musculature to control it,” Willy said. “In external focus, you might put a marker on the outside of her knee and ask her to push against it. But in some cases it actually works better to ask her to squeeze her glutes or push her knee out. You might also use both approaches; asking her to squeeze the muscles and push against a marker. It depends on the individual and her skill level.”

To support this idea, Willy noted a paper from the British Journal of Sports Medicine earlier this year, which reported that reduced hip strength may be a result of PFP rather than its cause.6

“Maybe we have some activation deficits,” Willy said. “You have pain, and the pain causes some neural inhibition, which makes it harder to activate your glutes. That’s why I think internal focus can be especially useful and very powerful, in the early stages. Even a runner with a lot of experience may have trouble controlling the mechanics of what’s causing the PFP, and that’s what needs to be retrained.”

Willy also clarified the relationship among real-time feedback, focus, and learning.

“Real-time feedback provides an external focus, in that you’re trying to get the patient to move something on a monitor—a line, bar graph, or cursor—that’s external to their body,” he explained. “There are pros and cons to that.”

For example, Willy and his colleagues are providing real-time feedback on multiple gait parameters to evaluate tibial loading in patients prone to tibial stress fractures. The problem, they’ve found, is that continuous feedback doesn’t facilitate internalization (or “automation,” at the risk of sounding robotic) of the new movement pattern.

The solution has been the “faded feedback” approach mentioned earlier.

“We ramp up their running time together with the amount of feedback, then eventually continue to increase run time while decreasing the feedback,” Willy said. “We want to move gait retraining from the lab to outside.”

Similarity

Other clinicians have had good results with similar approaches. Brian Noehren, PT, PhD, an assistant professor of physical therapy at the University of Kentucky in Lexington, told LER that combinations of internal and external feedback have worked well for him.

“The two coupled together is a powerful way to teach people to modify the way they run,” Noehren said. “As we gradually remove the real-time external feedback, we ask them to focus on the internal feedback. It challenges them, makes them more self-aware, and I think that’s good, because we are really trying to retrain the brain.”

In a study of 10 runners with PFP, Noehren and his colleagues found that the approach led to a significant improvement in hip mechanics, reductions in pain, better function, and a decline in vertical load rates.7

At the University of British Columbia in Vancouver, Michael Hunt, PT, PhD, associate professor of physical therapy, said he and his colleagues emphasize external focus, then gradually move the patient to more internalization.

“If we go with a solely external focus of control, they’re going to have a very difficult time trying to relearn that motor program,” he said. “We have to consider their lives outside of the lab, in the community, where they spend most of their time. They might be in a study for only ten or twelve weeks; what’s going to happen after that?”

Hunt, too, uses a faded feedback design, and has written about gait retraining for knee OA in LER.8 He and his colleagues train OA patients to toe out when they walk to redistribute knee joint loads away from the medial compartment. In a study recently accepted for publication in Physical Medicine & Rehabilitation, they taught people to increase the toe-out angle using one of three types of real-time feedback. The researchers performed simultaneous video-based gait analysis to measure actual performance relative to target goals.

“Over the course of treatment, we gradually introduce times within their training where they don’t see anything, to try to get them to internalize the motor relearning so they don’t become reliant on the external focus,” Hunt explained.

After 12 weeks, almost all the patients had significantly improved their performance.

“It doesn’t matter to me whether the focus is internal or external; if there are benefits biomechanically, or in terms of energy or function, I think that’s the most important thing,” Hunt said.

Pete Shull, PhD, an assistant professor in the School of Mechanical Engineering at Shanghai Jiao Tong University in China, agreed. Shull and his colleagues use a faded external feedback approach as well in their work with OA patients.

“They get instant feedback that’s very effective for making quick changes, but lasting change is another question,” Shull said.

In a recent study, their faded feedback system was effective; patients had retained their improved gait patterns at one month out, and the researchers are now doing longer-term testing.9,10

ACL issues

Feedback focus has gained particular attention in the prevention and rehabilitation of ACL injuries, perhaps because they’ve traditionally been challenging to address and clinicians are eager for anything that may help. A literature review of prevention programs recently published in Physical Therapy in Sport found that significantly better motor performance and movement technique were achieved with external focus than internal focus.11

Anne Benjaminse, MS, PT, the paper’s lead author, is a PhD candidate at the Center for Human Movement Sciences at University of Groningen in the Netherlands.

“As externally focused learning has proven effective in establishing a certain movement goal or effect, we thought it might also be potentially beneficial for injury prevention,” she said. “Lowering the chances of injury during a high-performance task is an integrated part of the task itself.”12

In another paper still in press, Benjaminse and her colleagues studied athletes after ACL reconstruction, and found that although external focus didn’t significantly affect jump distance, it was associated with a significantly better knee flexion range of motion on landing than internal focus.13

Kevin Ford, PhD, director of the Human Biomechanics and Physiology Laboratory in the School of Health Sciences at High Point University in North Carolina, has also studied the role of focus in ACL injury prevention, particularly in female athletes.

“I think we’re headed more toward external feedback,” Ford said. “That allows us to act more the way we would on the field.”

Ford and his colleagues presented findings in July at the World Congress of Biomechanics in Boston showing that female athletes performed better on a drop vertical jump test if they had either a real or virtual ball as a target, versus jumping without a target.14 And, in a pilot study published in June, they reported that real-time kinetic biofeedback during squat exercises was associated with improved drop-landing mechanics.15

At the University of North Carolina at Chapel Hill, researchers are investigating electromyographic biofeedback (EMG-BF) as an approach to ACL rehab and other problems. Brian Pietrosimone, PhD, ATC, an assistant professor in the Department of Exercise and Sport Science, told LER that experts often talk about reflex inhibition of an uninjured muscle following a joint injury, but that that doesn’t tell the whole story.

“There are issues with descending cortical function,” he said. “It takes more of a stimulus to get the primary motor cortex to send a descending potential to a muscle to get it to fire.”

In an abstract presented in June at the annual meeting of the National Athletic Trainers’ Association in Indianapolis,16 Pietrosimone and his coauthors reported that a single EMG-BF intervention in healthy individuals produced immediate increases in vastus lateralis corticospinal excitability and knee extension torque production, whereas a control intervention with no EMG-BF did not. In another presentation, they reported evidence that alterations in corticospinal pathways may be necessary for changes in movement strategies.17

Form and function

One obvious question about the role of externally focused feedback has to do with the balance of form and function. In most of the activities discussed so far, whether athletic or rehabilitative, function is paramount. Gabrielle Wulf’s personal epiphany came when she redirected her attention while windsurfing,1 where nobody much cares what you look like as long as you’re not drowning.

But what about gymnastics and dance—especially classical ballet—where the body’s form and position are just as important as how it moves? Might the traditional attention to detail, as taught through internal focus, still be appropriate in those situations?

Clare Guss-West, MA, a registered instructor for the London-based (though international) Royal Academy of Dance, acknowledged that 90% of dance instruction worldwide is still internally focused. But, when basic skills have been learned, she said, external focus often improves dancers’ mastery and fluidity. Guss-West, who lives in Zurich, has worked with Wulf and generally subscribes to her approach.

External focus doesn’t mean that teachers and choreographers stop breaking down movements, Guss-West explained; it’s merely a shift in how the task is approached.

“We’ve always taught that, especially with beginners, we had to break down every little movement,” she said. “But in my experience, that produces paralysis.”

She provided some examples of the alternative.

“You can say, ‘Let’s have a look at this position; maybe the arms are resting on water, or the foot is pushing the floor away,’” Guss-West said. “I’m always trying to use an image that is just beyond the body, so you still break things down but with different terminology.”

One distinction she draws between dance and athletic training is that in the latter, images often refer to real objects (eg, “reach for the basket,”), whereas in dance they’re usually imaginary.

“I often work with the continuation of lines of energy,” she said, by way of example. “If the dancer imagines shooting lasers through the hands or feet, you automatically get the extension you’re looking for. With images like that, even beginning dancers become more fluid.”

Sorting it out

External focus—whether on a nearby object, a biofeedback device or monitor, or an imaginary line of energy—appears to free the mind, and the body with it. The full applications of this understanding stand to benefit a wide range of people, whether they’re trying to stave off injury or improve performance. As the old coach said, sooner or later, we all have to get out of our heads and just play.

Cary Groner is a freelance writer based in the San Francisco Bay Area.

REFERENCES
  1. Wulf G. Attentional focus and motor learning: a review of 15 years. Int Rev Sport Exerc Physiol 2013;6(1):77-104.
  2. An J, Wulf G, Kim S. Carry distance and X-factor increases in golf through an external focus of attention. J Motor Learning Devel 2013;1(1):2-11.
  3. Wulf G, Shea C, Lewthwaite R. Motor skill learning and performance: a review of influential factors. Med Educ 2010;44(1):75-84.
  4. Perkins-Ceccato N, Passmore S, Lee T. Effects of focus of attention depend on golfers’ skill. J Sports Sci 2003;21(8):593-600.
  5. Miller A, Willy R. Retraining fixes faulty gait in injured runners. LER 2013;5(6):29-33.
  6. Rathleff M, Rathleff C, Crossley K, Barton C. Is hip strength a risk factor for patellofemoral pain? A systematic review and meta-analysis. Br J Sports Med 2014;48(14):1088.
  7. Noehren B, Scholz J, Davis I. The effect of real-time gait retraining on hip kinematics, pain and function in subjects with patellofemoral pain syndrome. Br J Sports Med 2011;45(9):691-696.
  8. Hunt M. Knee OA: The evidence for gait modification. LER 2012;4(1):39-43.
  9. Shull P. Gait retraining improves symptoms of knee OA. LER 2013;5(8):43-46.
  10. Shull P et al. Six-week gait retraining program reduces knee adduction moment, reduces pain, and improves function for individuals with medial compartment knee OA. J Ortho Res 2013;31(7):1020-1025.
  11. Benjaminse A, Welling W, Otten B, Gokeler A. Novel methods of instruction in ACL injury prevention programs: a systematic review. Phys Ther Sports 2014 Jun 19. [Epub ahead of print]
  12. Benjaminse A, Otten E. ACL injury prevention: more effective with a different way of motor learning? Knee Surg Sports Traumatol Arthrosc 2011;19(4):622-627.
  13. Gokeler A et al. The effects of attentional focus on jump performance and knee joint kinematics in patients after ACL reconstruction. Phys Ther Sports 2014 doi: 10.1016/j.ptsp.2014.06.002
  14. Ford K, Taylor J, Nguyen A-D, Hegedus E. Use of a virtual reality overhead goal improves vertical jump performance and biomechanics. Abstract presented at World Congress of Biomechanics, Boston, July 2014.
  15. Ford KR, DiCesare CA, Myer GD, Hewett TE. Real-time biofeedback to target risk of anterior cruciate ligament injury: A technical report for injury prevention and rehabilitation. J Sport Rehabil 2014 Jun 23. [Epub ahead of print]
  16. Florea D, McLeod MM, Gribble PA, et al. Electromygraphic biofeedback immediately increase his quadriceps corticospinal excitability. Abstract presented at the annual meeting of the National Athletic Trainers’ Association, Indianapolis, June 2014.
  17. Lefevre CE, Luc BA, Ericksen HM, et al. Associations between changes in quadriceps cortical excitability and sagittal plane jump-landing biomechanics following a four-week feedback intervention. Abstract presented at the annual meeting of the National Athletic Trainers’ Association, Indianapolis, June 2014.
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