03/06/2013 09:15 am ET Updated May 06, 2013

Fresh Ulnar Fractures in MLB

With injuries currently reported for 125 MLB players, a number of teams are already forced to rethink their opening lineups. The aging Yankees, contribute nine to the list, most in the majors. The Seattle Mariners is the only team that has not reported an injury to date. Sixty-nine of those not able to participate fully in spring training are pitchers, while another pitcher, Bartolo Colon is finishing out a 50-game suspension and will return on April 6. Some of the less acutely injured are expected to be in action by opening day, though, as is typical of recovery prognostications, optimism reigns, so don't hold your breath.

The hot injury of the young spring training season appears to be ulnar fractures. First it was Curtis Granderson, who throws right-handed but bats left, and was hit on the right forearm on February 24th by the first pitch he faced in a spring training game. He'd never even had the opportunity to officially test his prowess in his intended new position in left field. Manager Joe Girardi has since been quoted as saying that as a result, Granderson will return to center when healthy. It is predicted he will be out for ten weeks, returning in early to mid-May. The good news? Granderson will be able to maintain the strength and condition of his right arm and hand and so the injury will not affect his ability in the field. However, his bat will be sorely missed until he is 100 percent. Though ten weeks is best-case scenario, it is doable.

Left-handed starting pitcher, Martin Perez of the Texas Rangers was hit by a comebacker off the bat of Seattle's Brad Miller on March 3rd. Perez, a top Rangers prospect who made his first major league start in 2012 also has a non-displaced fracture, though of his left ulna. A non-displaced fracture is a crack (partial or all the way through a bone) that does not result in a separation of the pieces of bone or impact its alignment. Therefore, surgical repair is not needed. Though the Rangers are also hoping Perez returns to the lineup in early to mid May, his is a tougher order.

The forearm is comprised of two bones, the radius, and the larger of the two, the ulna. It is the ulna that, along with the humerus of the upper arm, forms the elbow joint. Both the radius and ulna meet the first of two rows of small bones of the hand (the carpals) to form part of the wrist. The connections between the two rows of carpals comprise the other portion of the wrist joint.

Though I was unable to find reports detailing Granderson's early treatments,'s "Foul Territory" reported that Perez is wearing a removable splint so that he could begin early range of motion exercises but will otherwise be immobilized full-time for at least two weeks before initiating any strengthening..

The healing response time of a non-displaced fracture is considered to be between four and six weeks, though varies based on age and general health. Though the players' ulnar fractures occurred in the forearm and not at the wrist itself, the wrist is immobilized initially to prevent the movement of the ulna. The forearm muscles control wrist movement and so they are put out of action, resulting in disuse atrophy and weakness. Immobilization generally results in some loss of mobility at the wrist as well as in the forearm's ability to turn the palm upward (supination) or downward (pronation). Mobility of the fingers may also be impacted, though to a lesser extent. Strength of the entire extremity is affected by disuse and so the players will work from the outset to maintain shoulder girdle strength and begin progressive strengthening of the entire upper extremity as soon as possible. This takes time.

Most routine ulnar fractures are due to a fall and occur at the wrist rather than in the shaft of the bone as with the players' impact injuries. Rehab for fractures at the wrist itself is likely to progress more slowly.