Healing rates and genetics
On Tuesday afternoon, the baseball community was shocked by Albert Pujols’ return from a fractured distal radius after only 15 days on the shelf. Now that he's back, people are wondering what makes him so different (aside from all that hitting, we mean), since initial estimates put him out until September.

At the time of Pujols’ injury, the best information anyone had suggested a September recovery. When medical professionals provide a prognosis of four to six weeks, they do so because that's where the recovery time falls in the majority of cases. On the whole, the time required for healing has decreased over the years, as medical techniques and information have improved. However, everything associated with healing is a piece of data, and—as is the case with most data—outliers exist.

Medical staffs do everything they can to optimize the chances of a quick recovery. Initially, some level of immobilization is required, and therapy starts. Fractures and other common injuries have fairly standard rehabilitation protocols, and bone stimulators are being employed more frequently by major-league medical staffs for fracture healing. So is there such a thing as being injury-prone? The answer is yes, and genetics can go a long way toward explaining why players return from similar injuries in different periods of time.

Genetics have been understood to influence healing rates for decades, but more research is being performed to determine how to improve natural healing. It has long been known that bones can heal themselves, but only relatively recently was bone morphogenetic protein 2, or BMP2, shown to be required for early fracture healing. BMP2 and thousands upon thousands of genes take part in the healing of a single fracture, and slow healing can be traced to the actions of one component among many.  

Very few players make it through the season without suffering an injury; in fact, at the major-league level, there is likely not a single injury-free player. When we start seeing a player consistently get injured and end up missing weeks or months on end, suspicions naturally arise—see Nick Johnson, Chipper Jones, Erik Bedard, A.J. Burnett, and Josh Beckett, among others.

Genetics can affect not only how quickly a player heals, but also whether the player gets injured in the first place. We’ve talked about the movie Unbreakable, in which Bruce Willis’ character has a genetic mutation that prevents him from being injured, while Samuel L. Jackson’s character has the opposite mutation and brittle bones (which is a real-life condition). While the movie vastly oversimplifies the issues, genes are vital in building the body and determining how much force it can take.

Genes give the muscles and tendons blueprints for how much stress or strain they can endure. They determine how quickly nerves can transmit information when the body is attempting to respond to threats. They even control the degree to which we feel pain. These are just a few of the genetically-influenced factors that dictate whether someone gets injured. For these and other reasons, capable sports medicine professionals never claim that they’ve healed a person after an injury; they endeavor only to optimize conditions for the body to heal itself.

We've only scratched the surface in our discussion about genetics and sports. The next frontier among sports medicine professionals in baseball—at least until someone synthesizes Prince Albert in a can—involves treatments tailored to genetic makeup and genetic testing to identify at-risk players.

As for Pujols, while it may be safe for him to play, it remains to be seen whether he will be as productive after his return. However, the role of the sports medicine staff in this case (at least in theory) isn't to factor in production, but to pass judgement on whether the player can safely participate in his sport without incurring any additional risk of injury.

Jon Lester, BOS (Left latissimus dorsi strain/cramping)
Remember the advantage in pitching depth the Red Sox had over the Yankees at the beginning of the season? Much of it has evaporated since spring training, and that trend continued as Lester felt cramping or strained his lower left latissimus dorsi in the middle of last nights' start and will likely spend some time on the disabled list. The latissimus dorsi is a very large muscle of the back and is one of the major contributors to velocity, and the earliest that a starting pitcher has returned in the middle of the season from a strained latissimus was 26 days, which does not bode well for the Red Sox staff.

Jose Reyes, NYN (Left hamstring strain)
Reyes' leg problems are well-chronicled, so whenever anything even hints at another injury to his legs, concern pops up immediately. On Saturday, Reyes felt tightness in his hamstring and was removed as a precaution before an MRI confirmed a minor strain of the left hamstring. The shortstop has not been placed on the disabled list yet and is considered day-to-day.

Reyes has been tremendously productive this year, but much of his production is predicated on the health of his legs, as is the case with most speedsters. The Mets obviously want him to return as soon as possible, but in light of his injury history and admission to rushing back two years ago, they’ll let some time pass before allowing him to return.

J.J. Putz, ARI (Right elbow tendinitis)
Putz was placed on the disabled list with right elbow tendinitis following a very rocky June. Most reports of his elbow surgery in 2009 overlook the fact that a partial ulnar collateral ligament tear and fraying of the flexor tendon were discovered. The ligament was not reconstructed at that time and therefore remains loose, even if only on the microscopic level.

Putz’s elbow has likely become looser since then, and since his muscles have to absorb the additional forces generated by pitching, he's been experiencing inflammation. Putz received a cortisone injection last week, but that only treated his symptoms, not necessarily the root cause of his pain. It's likely that he will need more than the minimum based on his injury history, despite reports to the contrary.

Carlos Gonzalez, COL (Right wrist contusion)

Gonzalez appears to have dodged a major bullet, escaping a collision with the wall somewhat reminiscent of the one involving Ken Griffey Jr. in 1995 with only a bruised right wrist. The mechanism of injury was a little different than the one in Pujols’ case, as Gonzalez's wrist appeared to flex forward rather than into extension.

Fractures are not associated with hyperflexions of the wrist as often as they are with hyperextensions, but they do occur in both cases. Sprains, bruises, and even dislocations of some of the wrist bones can result from this mechanism. Gonzalez was able to play catch on Monday and may require several more days off, but a move to the disabled list doesn't appear to be an option at this point.

Placido Polanco, PHI (Low back pinched nerve)
Polanco admitted recently to experiencing numbness running down part of his leg, as well as back pain that has caused him to alter his swing. We've gone over disc injuries and sciatica multiple times already this season, which goes to show how common such injuries are among baseball players. Polanco is 35 years old and has taken tens of thousands, if not hundreds of thousands, of swings and ground balls in his career. That amount of twisting and turning, especially while bent over, takes its toll.

Eventually, even years down the line, Polanco could end up needing surgery if he wants to remain active. For the present, if the Phillies can calm the inflammation through medication and physical therapy, Polanco can try to play through the injury. However, when it reaches a level at which the numbness has been traveling down the leg, especially when the player has to ask out of the game, there is a good chance of recurrence even if the pain does subside temporarily.

Fausto Carmona, CLE (Right quad strain)

What looked like a fairly innocent trip and stumble near the bag is going to cost Carmona some time, as the starter suffered a moderate quad strain. Given its importance in transferring weight from the drive leg to the landing leg, the dominant quadricep is an important part of the pitcher's kinematics. If a pitcher tries to pitch through a dominant right leg injury, his upper body and arm have to produce more force in order for him to generate the same velocity, which is just asking for a cascade injury.

Ryan Braun, MIL (Left calf strain)
Braun's left calf has kept him out of the lineup for the past several days, but he is not expected to hit the disabled list. His left calf will bother him while running, but it's also the leg that he strides off of when coming out of the batter’s box. That initial burst and stretch is commonly when the area between the muscle and the tendon itself becomes injured.

Flesh Wounds
Clay Buchholz
will get a third opinion on his back from Dr. Craig Brigham today… Luke Scott was placed on the disabled list with a right knee contusion, but it's the right shoulder with the known labrum tear that's the concern. He's going to have an MR arthrogram with dye to evaluate the labrum and the under-surface of the rotator cuff, and depending on the results, he may need season-ending surgery… After taking the ImPACT test and clearing several other clinical exams, Josh Harrison was deemed concussion-free… Troy Tulowitzki very mildly strained his right quad, but this is nothing like what he suffered in 2008, when he missed almost two months. Expect Tulowitzki back within the next several days… Mariano Rivera felt tightness in his right triceps, which limited his availability over the last several days. He should be fine going forward… Ryan Zimmerman hasnot only been having trouble throwing but also feeling soreness in the area of his abdominal surgery… Scott Baker left his start with a mild right elbow strain, according to the Twins…

Marlon Byrd came back from multiple fractures around his eye a mere 41 days after his beaning. Pretty impressive, if you ask us… Brian Tallet was placed on the disabled list with an intercostal strain… Marcos Mateo and his sore left elbow landed on the disabled list on Tuesday as well… Shane Victorino is out until later this week with a jammed right thumb and will be further evaluated by noted hand specialist Dr. Randall Culp… Mike Stanton is still having some haziness in his right eye despite receiving medication… Fernando Abad was placed on the disabled list with left shoulder tendinitis… Jon Garland will undergo surgery on his shoulder on Monday. He will miss the rest of the season… Andre Ethier was out of the lineup last night with a migraine. We would have one, too, if our paychecks came from Frank McCourt.