On the injury front, no major news is good news, especially during this time of the year, when optimism (no matter how misguided) springs forth from every camp. Fortunately, there are no major injuries to report today—something Cardinals' management and fans should be pleased about, given the scares and losses they have already had to deal with this spring—which gives us some freedom to examine some common leg injuries in detail.

Chris Carpenter, STL (Left hamstring strain)
Mike Stanton, FLO (Right quadriceps strain)

There are several muscle groups in the thighs, but the ones we hear about most often, as they relate to injuries, are the quadriceps and hamstrings. To summarize the anatomy, the quadriceps are located on the front of the thigh and involve four muscles (rectus femoris, vastus medialis, vastus lateralis, and vastus intermedius), while the hamstrings are located on the back of the thigh and involve just three muscles (biceps femoris, semitendinosus, and semimembranosus).

Hamstring strains occur more often than quadriceps strains for a few reasons. As a multiple joint muscle, the hamstrings originate on the ischial tuberosity (the bony part of your backside) and then attach all the way down on the knee. Multiple joint muscles, such as the hamstring, gastrocnemius (calf), and biceps brachii (arm), are more prone to strain because those muscles are trying to perform several functions at once.

As the back leg is getting ready to push off and drive the body forward, the knee is moving into extension, and in some cases hyperextends. The hamstrings normally reflexively contract to protect the knee from further damage. At the same time, the hamstrings are also trying to contract consciously to bend the knee in preparation for bringing the leg around for the next stride. When injury occurs, the hamstrings are often stretched too far from the knee—they extend before they start contracting, reflexively and consciously at the same time. These reactions occur through different neural pathways. As a result, the contraction can cause tearing of the fibers, usually at the junction of the muscle and the tendon.  

The quadriceps has only one component muscle, the rectus femoris, which crosses the hip and knee joint. The quadriceps is also significantly larger and stronger than the hamstring, causing many to propose strength imbalance as a factor. Previous studies have shown that the quadriceps-to-hamstring strength ratio should be about 60-80 percent in order to decrease the chance of a hamstring injury. In other words, if your quadriceps can lift 100 pounds, your hamstrings should be capable of lifting at least 60 pounds, but preferably more. (As a side note, this relative strength of the quadriceps is part of the reason why the PCL does not have to be surgically repaired as often as the ACL.)

Treatments for the two muscle groups are the same, except with different exercises. The area must be rested to prevent further injury, control swelling and bleeding in the muscle, and ensure full range of motion and gradual strengthening to normal. Mike Stanton is expected to miss 1-2 weeks (although it could be more, judging by how he was moving early on) with his right quadriceps strain. Very early reports on Chris Carpenter's left hamstring strain say that it is mild, although an exact timeline has not been released yet.

Michael Cuddyer, MIN (Wart removal, left foot)

Topical medication did not work well enough, so Michael Cuddyer had a wart removed from his left foot on Tuesday—he will be out for about 1-2 weeks, per reports. Plantar warts can be extremely painful once they've grow large enough, especially if they lie on a weight-bearing surface such as the heel, the ball of the foot, or under the big toe.

Plantar warts themselves are actually caused by a virus called the human papilloma virus (HPV), which is contagious and is commonly spread at swimming pools or public showers (such as in a locker room).  It's not something that is automatically caught on contact, but normal precautions should be taken (such as wearing shower shoes and the like). In baseball, it doesn't effect performance, other than as a result of pain: there is no direct biomechanical change, but if a player is altering his running or gait pattern due to the pain, the change could lead to sprains, strains, and stress fractures.

Commonly removed by freezing them with liquid nitrogen, such warts can be treated by multiple other methods, including acid—or, as in Cuddyer's case, surgical removal. Removing a wart surgically or with a laser can cause scarring in the area, which could be just as painful as the wart itself, so that option is generally pursued as a last resort. Once frozen, the wart dies, becomes blackened, and falls off in a few days.

Omir Santos, DET (Fractured left big toe)

Omir Santos had the misfortune to fracture his left big toe after fouling off a pitch during Monday's contest. It was initially announced as a bruise, but further tests confirmed the fracture—he's expected to miss 4-6 weeks. Fortunately, it does not sound like the fracture needs to be surgically fixated, and it should heal well on its own. Fractures of the big toe have to be treated conservatively and not just taped to the other toe. The big toe bears a significant amount of weight and is a major part of the kinetic chain that transfers energy all the way up the leg. Another complicating factor is the position Santos plays: as a catcher, he is on his toes throughout the whole game (at least physically, if not mentally, too). That requirement demands that the Tigers and Santos take it slow and make sure that the fracture has healed properly before getting him back behind the plate. In the meantime, rabid Santos fans looking for a fix should direct their attention this way.

Jesse Carlson, TOR (Left shoulder inflammation)

Jesse Carlson underwent MRIs and was diagnosed with left shoulder inflammation after the area was deemed structurally sound—at least, as structurally sound as a pitcher's shoulder can be. The shoulder gets most of it's stability from its muscles and requires this dynamic stability to be able to perform even everyday tasks around the house, never mind throwing a baseball for paychecks. The difficulty in treating shoulders is that feedback into another system often complicates the issue. For instance, if there is pain from inflammation, it causes the muscles to weaken because they aren't being used as they normally would. This weakness causes impingement, which in turn causes further inflammation, and the cycle goes on and on until it is treated appropriately. Normally the easiest way to break the cycle is to limit the pain, follow it up with strengthening, and lastly perform surgery to correct impingement or degenerative changes in the joint. What Toronto will try to do is calm the area down with some physical therapy and then make sure Carlson has the proper strength before letting him back on the mound. He should be ready somewhere between two weeks from now and Opening Day.

Flesh Wounds: Corey Hart did not respond to his treatment for the last few days. It was determined that he would need a few weeks off to fully rest the lower abdominal muscle that he strained after slipping… Josh Beckett took a ball off his melon while in the outfield during batting practice. Beckett was reportedly dealing with concussion-like symptoms, but that could mean anything from having a headache to being irritable. He said that he already felt significantly better the next day… Brent Dlugach dislocated his left shoulder Tuesday making a great catch. Further tests will be required in order to determine the extent of the damage.

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Great write-up of the leg muscles. Highly-detailed, now we have a full understanding of how these things work.

I think it would be a good resource if you could create an "Injury Glossary" - basically just copy these write-ups (the wart one as well), that can be referenced in future articles.