The sports medicine practitioner has two goals: one, to keep the athlete healthy, and two, to help that athlete perform to the best of his or her ability. But when it comes to lower extremity bracing, those two objectives sometimes butt heads. Even when bracing is indicated to protect a joint during rehabilitation or prevent recurrent injury, will an athlete’s performance be affected? The short answer: It depends.
by Cary Groner
The sports medicine community has long been divided as to the merits of prophylactic or rehabilitative bracing of the knees and ankles. Some orthopedists won’t let their post-surgical patients onto the field without a brace, for fear of re-injury. Others don’t let them go with a brace, out of concern that it will become a crutch that prevents players from regaining their full skills. Still more make their decisions based on the individual athlete. Nevertheless, as experts continue to thrash their way through this thorny debate, a consensus is emerging about certain aspects of bracing and their effects on injury prevention and athletic performance.
To brace or not to brace? Every day the question confounds trainers, surgeons, coaches, and of course athletes themselves. One consideration, it turns out, is whether the body part in question is the knee, the ankle, or even the foot.
The bee’s knees
In knee research, one recent study found that bracing increased knee flexion angle and decreased peak ground reaction force during a stop-jump task.1 Other research has found that knee braces don’t significantly affect speed or agility;2 may be valuable for rehabilitation but decrease local blood flow and increase fatigue;3 and protect from lateral blows but may slow sprint speeds.4
According to Kenneth Gavin, CO, who practices at Audubon Orthotics and Prosthetics in Colorado Springs, bracing for minor injuries such as sprains can often be accomplished with a simple knee sleeve rather than a full hinged brace.
“We want to provide a little extra warmth and proprioceptive feedback,” Gavin said. “The compression helps prevent swelling, and the sleeve restricts motion a little so things heal.”
One well-known study has affected bracing strategies at the college football level, said Tim Hewett, PhD, director of the Sports Medicine Biodynamics Center at Cincinnati Children’s Hospital. Research on Big Ten teams found that preventive bracing helped reduce medial collateral ligament injuries—but only in linemen, linebackers, and tight ends. Other players, particularly those in “skill positions” (e.g., running and defensive backs) were negatively affected by the braces, whether in performance or by a slight increase in injury risk.5
“Interior linemen are now wearing prophylactic ACL [anterior cruciate ligament] braces, but no one else wears a brace unless they’ve had an injury,” Hewett said.
God in the details
Hewett is well-versed in the intricacies of the arguments surrounding the use of knee bracing.
“Prophylactic [ACL] braces tend to decrease hamstring activity, which is not a good thing because the hamstring pulls the tibia back relative to the femur and takes stress off the ACL,” he said. “From a rehabilitative standpoint, there is little strong evidence that the brace alters the biomechanics of the knee; and from an epidemiological perspective, there’s little data to say they prevent re-injury of the graft.”
In fact, Hewett said, Canadian researchers determined that after ACL reconstruction, players wearing a simple neoprene sleeve had the same outcomes as those fitted with a structured metal brace.6
So when players and trainers swear by their braces, what’s going on?
“There are kids who tell you they absolutely cannot play without that brace, and despite the lack of strong evidence, there’s a place for braces in the field,” Hewett acknowledged. “We just don’t know whether the benefits are biomechanical, proprioceptive, or psychological.”
Hewett and his colleagues did a study on patellofemoral knee sleeves, for example, and found a significant beneficial effect on function. One reason, he thinks, is that a normal ACL contains between 3% and 5% nervous tissue. It’s full of mechanoreceptors that sense the position of the knee in three-dimensional space and provide feedback about position, force, and torque. When the joint is reconstructed using tendon tissue, the body and brain lose that vital feedback. Hence the possible value of a sleeve.
“Having something external to the knee joint to provide a more tactile sensation of the knee in space may be helpful, which would explain the findings of the Canadian researchers,” he said.
Many physical therapists and surgeons feel that braces should not be worn during rehabilitative exercises, Hewett continued.
“If you want neuromuscular adaptation to the loss of those proprioceptive receptors in your knee joint, you should develop them independently of a brace,” he explained. “If you use the brace, it should be done during play, so you can protect the knee.”
Jonathan Chang, MD, a clinical assistant professor of orthopedics at the University of Southern California, said that decisions about bracing may be affected by strategic matters beyond the purely physical.
“The purpose of bracing in the short term is to allow return to play when it’s unlikely to aggravate the injury,” he said. “A good example is an isolated MCL tear, where with good rehabilitation and a hinged brace, players—particularly linemen—can be back in six to eight weeks. A lot depends on the player, the team’s depth at that position, and the time of the season that the injury occurs.”
In practical terms this means that a guard with, say, an MCL and meniscus tear, might opt for bracing and rehab if the injury occurs in week 2 (the NFL regular season is 17 weeks long). If it happens in week 14, however, it will take too long to come back, so he might as well end his season and proceed straight to surgery.
In other situations, matters become more complicated.
“There is no tried-and-true decision tree,” Chang admitted. “Each case is different, and that’s why all the teams have doctors to help make that determination.”
Ligament braces, of course, are theoretically designed to prevent the abnormal joint motion that often follows an injury. An MCL tear is easier to brace, Chang believes, because it is a more peripheral ligament, and the action of the brace is more congruent with the function of the ligament itself. It’s more difficult to successfully brace internal ligaments such as ACLs.
“The problem in that case is that you have an external device trying to mimic the performance of an internal ligament that is closer to the axis of rotation,” he said.
Chang also noted that simple superstition can come into play.
“If you watch a game carefully, you’ll notice that at the beginning a significant number of players on both teams are wearing braces,” he said. “But by the end, those on the losing team start to believe the braces are slowing them down, so they take them off. Players are extremely suspicious of anything they think might be putting them at a disadvantage.”
Faking them out
Another kind of strategy comes into play in making bracing decisions, according to Jeremy Murray, CO, OTR. Murray, who is in private practice at the Michigan Hands and Sports Rehabilitation Center in Warren, MI, works with a variety of professional athletes including members of the Detroit Pistons basketball team.
Football linemen wear braces on both knees, not just as a prophylactic measure but to hide injuries, he said.
“Bracing both knees masks your weakness, so you don’t have people going after it,” he said. “In pro basketball, you never see a player wearing a big, bulky ACL brace in a game, because everyone will see it and cut to your bad side.”
In a reverse of the strategy reported above by Hewett, in fact, Murray said that in basketball, most players practice in their braces but take them off for games.
Because lateral ankle sprains are the most frequent sports-related injury, scientists and clinicians are motivated to determine optimal bracing strategies. As with knee bracing, research into the effects of ankle bracing can be contradictory; nevertheless, in recent years certain themes have emerged.
In a 2005 meta-analysis, for example, scientists at Indiana State University concluded that the benefits of preventing injuries outweighed the braces’ small impairment of performance.7 A German study from the same year compared 10 different braces (rigid, semirigid, and soft) in subjects with chronic instability and determined that significant performance differences were largely subjective.8 Another 2005 study at Georgia State University found that ankle-stabilizing orthoses (ASOs) were likely to prevent sprains during activities involving lateral cutting but didn’t impair performance.9
Laurie Tis, PhD, ATC, was an advisor to the authors of the Georgia State paper in her capacity as coordinator of the graduate sports medicine program there, a post she held for 18 years. (Tis is now an associate dean and professor of academics, sponsored programs, and technology at nearby Kennesaw State University.)
“In our drop-landing study,10 we found that ankle braces reduced impulse forces, and a lot of biomechanics people agree that those forces—when you first land—are associated with impact-related injuries such as stress fractures,” she said.
Tis believes that well-designed ankle braces reduce injuries without affecting athletic performance.
“Coaches and athletes always want to know—if I put on a functional brace, can I still play? Can I jump as high, run as fast? Can I move as well? The answer is yes,” she said. “And these braces don’t just prevent ankle sprains; they also provide some protection against chronic injuries, things we wouldn’t normally expect. Do your landing mechanisms improve? There’s a limited amount of evidence to suggest they do, and that will reduce the likelihood of injury as well.”
Tis, too, is aware of strategic considerations in bracing decisions.
“In a high-pressure [NCAA] Division 1 situation, if I can show that I’m preventing injuries with bracing, the coaches will put people into them,” she said.
According to Tis, AFOs are used primarily in volleyball and basketball. Football players have their ankles taped, and soccer players are the most finicky of all because braces won’t fit into their shoes and even taping can affect their feel for the ball.
“Sport specificity becomes a big issue in how we handle athletes,” Tis said.
Healing while playing
The most basic way in which a brace can improve performance, of course, is by facilitating an athlete’s return to action. When a player suffers a stress fracture of the foot, for example, most practitioners think there’s little to be done except rest for six or seven weeks until the injury heals. But a North Carolina maverick is turning that conventional wisdom on its head.
Harvey Johnson, CO, of Hillsborough, NC, has developed a unique bracing system that allows stress fractures to heal while athletes continue to practice and play. If this sounds impossible, consider some of the athletes he’s helped: several World Cup soccer players; a variety of Duke University basketball stars including Monique Curry, Elton Brand, Bobby Hurley, Daniel Ewing, Krista Gingrich, and Lindsey Harding; players from Vanderbilt and other universities; Stanford wide receiver Evan Moore; and his older brother, former UC Davis basketball standout Ryan Moore. Ewing, for example, played successfully with a Jones (fifth-metatarsal) fracture, which most clinicians would consider impossible.
Johnson, who has published his findings in Foot & Ankle International(11), has a threefold strategy. First, he fabricates an orthosis that redistributes forces away from the fractured bone; second, he makes a thin sheath that surrounds the foot to help immobilize the bones; and finally, he dismantles the shoe and puts it back together with a specially reconstructed sole.
“It’s always about redistribution of forces and changing the alignment of the foot,” Johnson said. “The design is based on the individual’s particular pathology, and the brace isn’t just used on metatarsal fractures; it’s also for foot sprains as well as navicular and Lisfranc injuries, and fasciitis. With metatarsal fractures, obviously surgery is sometimes necessary, but postoperatively orthotic management can be critical.”
Johnson gets a lot of inquiries from schools, but says the athletes always have to come to him.
“I can’t tell people how to do this over the phone,” he said. “It’s a complex and delicate brace to make because it sits on a very bony, rigid part of the foot.”
Johnson said that for him, everything comes back to the profound understanding of biomechanics he learned from a Colorado physical therapist named Beverly Cusick.
“I can’t eliminate all the forces, but I can reduce them so the person can perform,” he said. “Pain tells us everything; if we get the person playing without pain, or at a [pain level of] one out of ten, we know we’re doing OK. Instead of getting players back in seven weeks, I’m getting them back in three.”
Johnson is using this knowledge to go beyond healing into improving performance with custom orthoses, which athletes wear after the fracture is healed.
“Reducing pain improves performance, of course, but aside from that, if you can align a foot so that it becomes a more effective lever arm, if you reduce pronation by a third, your force systems are more efficient,” he said. “Your muscles will be working closer to their mid-range, where they’re more powerful. I believe that with some athletes, you can make them more efficient.”
Cary Groner is a freelance writer based in Northern California.
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