With the U.S. Open heading into full gear, all eyes are again on golf. Also, now that summer has arrived, more and more average Joe's (and Jane's) are hitting the links. Most are ecstatic, some are limping.

When Tiger Woods stepped up to his first competitive tee shot since having arthroscopic knee surgery eight weeks ago, all eyes were on him, and his knees. I was not at all surprised that his first shot lifted off a large chunk of turf and went far far out of play. Not typical for Tiger, but fairly typical with someone whose knee is not quite 100%.

He struggled in his first round, wincing a few times when he swung, and admitted afterwards that his knee was a little sore. At the end of the day, he somehow hung in there not far behind the pack, a credit to his talent and determination.

In a recent blog entry, I talked about Tiger's knee surgery, anticipated recovery and potential problems.

Compared to other sports, golf is relatively safe. Injury rates are relatively low, and the types of injuries that do occur are often not severe in nature. However, injuries and other musculoskeletal ailments certainly do occur.

In my orthopedic practice I see several golf enthusiasts per week with aches and pains that are limiting their enjoyment of the game, or stopping them completely. Although golf is not considered a "high impact" activity, one should not assume that the forces exerted on your body are not substantial.

In fact, the golf swing puts tremendous forces across the body in a somewhat unnatural manner, and those forces are not distributed equally across your frame. Just like with the tennis swing, there are inherent imbalances. And those high stress, high force imbalanced loads occur over and over and over, as with any repetitive movement sports activity.

Common golf injuries include issues with the lower back, wrist, elbow, shoulder and knee. In my private practice as a knee specialist, I see a variety of knee problems in golfers.

For many years I've heard the term (and I'm sure you have as well) "runner's knee." It is a bit of a misnomer. Runners do indeed get a variety of knee conditions, but there is no one single "runner's knee" ailment. There are a variety of conditions that can cause knee pain, swelling and other problems with runners. The same is true of "golfer's knee."

When it comes to knee pain, especially in golfers, all knees are not created equally, and it takes a careful evaluation to determine the exact diagnosis.

The most common knee problems in golfers include:

• Torn meniscus. The meniscus is a C-shaped shock absorber. There are two in each knee, one on the medial side (medial meniscus) and one on the lateral side (lateral meniscus). The meniscus can tear from a single injury such as a fall or severe sudden twisting episode, or more commonly (especially as we age and some of our tissues weaken) it can tear from even relatively minor repetitive twisting or squatting maneuvers.
  
  The golf swing puts tremendous force on the inner side of the lead leg (i.e. left leg in a right-handed golfer). This is especially true with Tiger's biomechanics, which tend to throw even higher forces on the inside of his left knee.
  
• Osteoarthritis. Normal knee joints have a healthy, thick, smooth, slippery and well-lubricated cushion on either side of the bones (femur and tibia) that make up the joint. When that cushion begins to wear, it is called arthritis. In some cases the wear is minor, and other times the cushion can be completely worn out and "down to bone."
  
  Osteoarthritis (the most common form of arthritis) can be caused by old injuries, genetics, poor alignment (i.e. bow-legged or knock-kneed), repetitive microtrauma (like swinging a golf club over and over and over) or just wear and tear. The result can be pain, stiffness and/or swelling.
  
  A knee with arthritis can flare up from the repetitive twisting needed in golf, or even just walking the golf course. Interestingly, we are seeing arthritis in younger and younger patients.
  
• Tendinitis. The tendons around the knee can become inflamed and irritated from overuse and repetitive strain.
  
• Chondral defect. Sometimes damage to the joint surface can be pretty localized. The result is a divot or pot-hole in the joint surface cushion. This can result in pain and even floating chips or loose bodies in the knee. Left untreated, many of these defects will spread and create arthritis.

So, if you are a golfer with a sore knee, my best advice is to get it checked out, and get an accurate diagnosis. This is usually accomplished with a simple office visit and some x-rays. Sometimes an MRI will be needed to shed additional light on the diagnosis.

Most conditions can be treated with conservative simple measures including ice, rest, medication and therapy. Also, talk to your golf pro and consider taking a lesson. Often there is a biomechanical or technical flaw in your swing and your stroke that may be setting you up for injury. If surgery is needed, it can usually be done as an outpatient via arthroscopy with a quick recovery, just like Tiger.

But something to learn from Tiger's experience is that even if you are as fit, lean and motivated as Tiger, full recovery can take time, and you must be patient. Also, remember what I said earlier: Every knee is different -- so talk to your doctor and get the full details of the type and severity of your problem. Also find out if it's something that can be completely cured, or if it is something you are going to need to learn to live with, manage and/or work around.

Have you had significant knee issues related to golf? What has helped you? Share your stories. You never know, maybe Tiger will be reading.