Knee of the Tiger: Limping to the Challenge of Your Rivals
As I’m sure many of us have heard Tiger Woods (Real name: Eldrick Tont Woods) has run into some problems in recent years. During the U.S. Open in June 2008, Woods seemed to be in pain, occasionally wincing after tee shots and favoring the left foot to keep weight off of it. Despite the pain, Woods managed to force the game into a sudden death playoff with Rocco Mediate which Woods won when Mediate missed his putt for par.
Now I’ll grant you that the phrase ‘sudden death’ can make anything more interesting, even golf, but what everyone considers the most impressive feat of that day is the fact that Tiger Woods managed to win while suffering a torn anterior cruciate ligament (ACL) and a double-stress fracture of his left tibia. Or as fellow PGA golfer Kenny Perry so succinctly put it, “He beat everyone on one leg.”
For those of you familiar with sports, you may not be surprised to hear of an ACL injury in basketball, football, rugby or American football since most injuries of that kind are due to quick acceleration, deceleration or changing direction (especially in contact sports), but a torn ACL in golf? Unpossible. And in this case, you’d be right. Although chronic problems may have contributed to the injury, the actual ACL injury happened while running near his Florida home sometime after the British Open in 2007, according to Woods.
This injury left Woods conspicuously absent from the world of golf for the latter part of 2008 (it also left spectators conspicuously absent from golf), and although he seemed to be getting back into the swing of things since he started playing tournaments again in February 2009 before taking a break at the end of this year. But is this injury going to intensify his chronic knee problems and continue to handicap him, or are there ways to manage the condition? Furthermore, where the heck is an ACL and what does it do?
Glad you asked, because the ACL plays an important role in stabilizing your knee so the lower leg doesn’t wobble around under you like a pirate’s poorly fitted peg leg. In order to more fully understand the impact of Tiger’s injury on his golfing performance, we’ll take a look at some basic knee anatomy.
The knee is often considered the most complex joint in the body because it allows for flexion and extension (right leg in, right leg out) as well as slight rotation (shake it all about), and it has to do all this while supporting the full weight of the human body. The complexity of the joint is not manifested in the bones as the knee is comprised of only 3 bones; the femur (thigh bone), the tibia (big, weight bearing shin bone in the lower leg) and the patella (kneecap). The fibula (little bone in the lower leg that runs down the calf) connects to the tibia below the joint and is thus not included in the actual joint functioning.
The way these bones are shaped and fit together is integral to the joint’s function. As you’ll see from the diagrams, the bottom end of the femur and the top end of the tibia where they form the knee joint, are formed into two rounded knuckles which are referred to as the Medial and Lateral condyles. This doesn’t make a whole lot of sense until you do what the medical profession did and think of an imaginary vertical plane bisecting your body equally into left and right halves, otherwise known as the median plane or midsagittal plane. In reference to this imaginary plane, the condyle on the outside of either knee is referred to as the Lateral condyle because it is further away from the median plane and the condyle on the inside of the knee is called the Medial condyle for obvious reasons.
These condyles are incredibly important because they function as a point of attachment for the many tendons and ligaments necessary for the function of the knee, while the space in between the condyles of the femur creates a groove for the patella (kneecap) to slide through. The condyles of the femur and tibia are what support the weight of the entire human body, which in some cases, can be considerable.
In order to prevent these bones grinding together during joint movement, there are pads of fibrous cartilage-like tissue between each condyle of the femur and tibia called menisci (plural), if you couldn’t guess already, they’re referred to as the Lateral meniscus and the Medial meniscus. The menisci of the knee are attached to each other as well as to surrounding parts of the knee by fibers of varying strength. Despite being anchored firmly in the knee, the menisci are sufficiently free moving to allow them to slide over the top of the tibia when the knee is rotated, while also being able to move over the condyles of the femur during extension or flexion of the knee.
Other forms of protection against wear and tear in the knees come in the shape of bursae, which are saclike structures that are strategically placed to reduce friction between soft tissues as well as around prominent bone structures in joints. There are at least 13 bursa in and around the knee, I told you it was a complicated joint. While usually not a problem, any of these bursae may become irritated, and possibly fill with fluid, becoming a cystic mass putting pressure on the joint instead of reducing friction.
Actually linking the bones together are the ligaments of the knee. The ones least relevant to us today are the patellar ligament joining the patella to the tibia, and the quadriceps tendon which connects the quadriceps muscle to the patella. Today we’ll focus on the four major ligaments of the knee; the cruciate ligaments and the collateral ligaments which are there for the purpose of stabilizing the knee.
The medial collateral ligament (MCL) runs from the medial epicondyle of the femur (fancy terminology for the outside of the femur’s medial condyle) to the medial condyle of the tibia, it prevents the knee from bending inwards towards the median plane by forces applied to the lateral side of the knee, which are called valgus forces. The lateral collateral ligament (LCL) runs from the lateral epicondyle of the femur to the top of the fibula and protects against varus forces which push the knee away from the median plane. If you’re an avid sports watcher, you may have seen a football, rugby or American football video where someone gets tackled hard and comes out with a knee bending to the side. That would be strong evidence for a collateral ligament injury.
Now while the collateral ligaments protect the knee from bending the wrong direction, i.e. sideways, the cruciate ligaments are there to protect your tibia from sliding out from under your knee either forwards or backwards. The posterior cruciate ligament, or PCL, (posterior refers to it being located towards the back) is attached between the medial condyle of the femur to the posterior intercondylar area of the tibia (in between the condyles), it prevents the lower leg from moving too far backwards relative to the femur and can usually only be damaged by direct trauma. The anterior cruciate ligament, or ACL (posterior/back, anterior/front) runs between the lateral condyle of the femur and the anterior intercondylar area. This ligament prevents the tibia from moving too far forward relative to the femur and is unfortunately easy to injure, usually while the knee is being twisted or bent.
Now we’ve waded through that terminally exciting parcel of medical academia, we can move onto more Tiger-centric knee information. Woods has had a string of surgeries on his left knee throughout the years, starting in 1994 with a surgery to remove a benign tumor. During this surgery doctors discovered substantial scar tissue related to childhood injuries from skateboarding, crashing dirt bikes, etc. Although it makes me wonder, if Woods had practiced skateboarding as much as golf when he was a kid, maybe he could’ve given Tony Hawk a run for his money? At least the games would’ve been better.
In 2002, Tiger went in for arthroscopic knee surgery, which is a minimally invasive surgery procedure where the arthroscope and other surgical tools are inserted through holes made in the skin in order to reduce the amount of anesthetics, cutting and recovery time of the surgery. The 2002 arthroscopic knee surgery was done to drain fluid around the ACL and remove a benign cyst. Apparently Woods enjoys surprising his doctors because this time during surgery, it was discovered Woods’ ACL was overly stretched.
Now, golfing can be fairly inimical to your knees, depending on your swing. For right handed players, on the back swing your left foot is planted as you rotate your hips to the right, this means that your tibia rotates externally relative to the femur and the rest of your body. On the swing and follow through golfers transfer the weight to the outside of their left foot, rotating the tibia inwards while the femur rotates externally bringing the hips and trunk around in rotation to the left. This can put a lot of stress on the knee joint if you don’t carry the kinetic force generated by your swing into the trunk and arms, leading to rotational overload of the knee.
Before his surgery in 2002, while many people stood in awe of Tiger’s swing, although he did have a nasty habit of forcing his knee into hyperextension for more distance. This puts an incredible amount of force on your knee, and when the knee is in hypertension it puts a much greater force on your ACL relative to the PCL, which could have contributed to the worrying stretching that doctors found in the ligament during the arthroscopic surgery in 2002.
For those who either really like golf or just enjoy stalking Tiger Woods, you’ll probably know that in 2003-4 after having recovered from his surgery, Woods decided to change his swing. After a period of time, he drifted away from his previous swing coach, Butch Harmon and ended up working with Hank Haney as his swing coach from early 2004.
Now, I understand nothing about keeping the golf club in the same ‘plane’ on the upswing and down, but both Haney and Woods consider this important as it will allow the body a tighter swing. What they’re really talking about is making sure when Tiger swings the club, he’s taking full advantage of the kinetic chain effect where energy is more efficiently transferred from the feet, through the knees and hips, up into the rotating shoulders, down the arms and through the club into the ball. The less energy lost in transfer through the chain means less stress put on the joints, so the smoother the swing, the less wear and tear on Tiger’s knee.
While Tiger’s game started to improve in 2008, meaning the new swing was working for him, something had gone wrong as he was once again limping on the green during the U.S. Open. A few days after the tournament, Tiger announced he would be undergoing surgery once more. This time it would be for a torn anterior cruciate ligament and a double stress fracture in his left tibia.
When Tiger found that his ACL had been stretched after his previous surgery in 2002, he may have started training his legs hard to compensate, as having strong quadriceps and hamstrings lends extra support to the knee. However, repeated overworking after the surgery may have contributed to or even caused the stress fractures in his shin. As for the ACL injury he picked up while running, it is entirely possible that with his history of knee problems and an already stretched ligament, he may have just put his foot down wrong, forcing his knee into hyperextension which caused the tear in his ACL.
Now in 2009, Tiger seems to have rehabbed well after the 2008 surgery on his knee as he has been doing fairly well this year, winning a number of tournaments. However, assuming Woods intends to keep playing the game into the SPGA, or at least keep walking without pain for the rest of his life, he’ll need to look after his knee. In order to do this, he’ll need to condition his legs so that the leg muscles help support the knee, he’ll also have to avoid underestimating the power of a proper warm up and stretching regimen. Then again, he plays sports for large sums of money, so we’re probably not springing any surprises on him.