Sports medicine experts weigh in on Eagles' injuries and Chip Kelly's sports science program

Every team in the NFL cares about injury, but the Philadelphia Eagles put more emphasis on preventative medicine than most. Chip Kelly's sports science program is shrouded in mystery, but what little we do know about it seems to say that the Eagles are interested in curbing muscle injuries through monitoring and prevention.

And yet, there have been several injuries to the Eagles this season. In last week's loss to the Cowboys the Eagles suffered several key injuries, including Kiko Alonso and Mychal Kendricks. And earlier in the week, running back DeMarco Murray suffered a hamstring injury during practice.

To help us sift through all the injury news, we've partnered with Dr. Arthur Bartolozzi, former team physician for the Philadelphia Eagles and Flyers and current director of sports medicine at 3B Orthopaedics at Aria Health, as well as Justin Shaginaw MPT, ATC, former team physical therapist for the Philadelphia Charge and the Philadelphia Kixx, and current physical therapist and coordinator of sports medicine for 3B Orthopaedics at Aria Health and athletic trainer with the US Soccer Federation.

We spoke with these two experts about the Eagles' recent injuries, and more. To hear the audio version, check out this week's episode of BGN Radio:

What is an ACL tear?

Dr. Arthur Bartolozzi: A ligament is made of a number of fibers. And the ACL has a number of complex fibers that all function to stabilize. When [the knee] becomes unstable, it can rotate more than its supposed to, or twist more than it's supposed to. And it can actually twist enough to make the player feel like the knee is insecure or comes out of joint.

When you tear a ligament, a sprain is technically a tear. So we grade the sprain based on how much tearing there is. If there's a little bit of tearing, there's no looseness. If there's a lot of tearing or a complete tear, there's a lot of looseness. So we grade that 1, 2, 3. Most types of sprains we diagnose are in the range of 1 or 2, where there may be a little bit of pain; a little bit of weakness or a little bit of looseness.

What does it mean when a player gets a second opinion?

AB: Sometimes you want to have an opinion from someone who's not intimately involved with the process. A lot of players, while they have confidence in their medical staff and doctors, sometimes want to have another set of eyes. And when I was working with the Eagles, I welcomed other opinions, because I thought it would be helpful to really instill confidence in the player, and to make sure the player is aware of exactly what we're telling them is exactly what's being said. And that's not always the case.

And so if there's a difference of opinion, then it creates a venue for discussing. "Hey, what's up? Why are there differences?" But really it's mostly so the player has confidence in the direction he has to go.

How long is a recovery for Kiko Alonso's low-grade sprain?

AB: Well, let's talk about this particular player. This is a very tricky process. Grade 2 determined by MRI is different than Grade 2 determined by a physical examination. Sometimes these ligaments, even after being replaced, don't appear entirely normal on the MRI scan. And Grade 2 means there's some laxity in the knee, or some looseness in the knee, that may not have been there before.

So partial tearing, but not a complete tear, where the fibers are completely disrupted and the knee is totally loose. But sometimes a partial tear results in looseness that places you at risk for further injury, or looseness that the player can proceed with. And sometimes, players can play with a certain amount of looseness and never even notice it.

So some of it is going to be based on the examination of his knee and checking out how loose it is, and then how does the player feel when using that knee? Most ACL surgeries restore the knee to near-normal, and not exactly normal. But it's close enough that players can play without a problem.

What should fans know about DeMarco Murray's hamstring injury?

AB: Hamstrings are a significant problem. Muscle injuries in general are significant problems in sports. There have been some studies that show that if you have 25 players on a team, you can expect 15 muscle injuries. If you have 50 players, you can expect 30 muscle injuries. And these really account for most of the time missed in playing football. So whether it's a bruised muscle or a strained muscle, muscles are injured.

The reason why hamstrings get injured is because the muscle, as it attaches to the tendon, is so strong that it actually exceeds the normal ability of that stuff to stay attached, so they rip off a little bit. It rips off, it causes pain, causes a little bleeding. And it hurts!

What places you at an increased risk for muscle injury is fatigue. And so a lot of these injuries occur either toward the end of the half or the end of the game, or in practice after an extensive practice, or the next day after an extensive practice. So fatigued muscles have a higher risk of injury. So previous injury also places you at increased risk. And most of these hamstring injuries are relatively minor muscle tears. They're not significant to the point where the muscle tears off the bone.

The large majority of these injuries are graded from Grade 0, which means you can't even see it on an MRI scan, or Grade 1, where there's just a little bit of swelling but no obvious tearing. Those types of injuries account for the most common causes of injury. And there are serious ones, where you've seen players miss half or all of the season with serious injury. So most are minor.

In DeMarco Murray's case, as is the case with most of these injuries, it takes a week or two to get back to physical activity. And players often know where they stand, having had previous injuries like that.

What is sports science, and can Chip Kelly's program really prevent injuries?

Justin Shaginaw: Across all sports they're really trying to use sports science to limit injuries and improve performance. You can see this with the NBA starting to use metrics now. Soccer, we've used it a little bit longer than the NFL, looking at heart rate monitors and work load and that kind of thing.

Sports science is really trying to find the balance between sure an athlete is as fit as possible without overtraining them. If you're not in shape, you're more likely to sustain injury, especially muscle strains. And if you're fatigued you're at more risk. And I think that's the sweet spot that all the sports science people are trying to figure out.

I think this is new to football, and if you look at fitness and football, it's a different animal than most other sports because if you look at the total work done in a football game, it's not a lot compared to a basketball game or a hockey match or a soccer match.

And I think Chip Kelly, with the increased plays, is trying to improve fitness over players. You may not see a return in investment of this for another two or three seasons until the players really buy in; they've gone through a season or two of the sports science program. I think that's really when you might start to see a payoff.

For more information on the medical experts interviewed here, visit the 3B Orthopaedics at Aria Health website.