One of the more traumatic and unheard of baseball injuries of recent years, Cody Ross' dislocation and fracture of his right hip last August conjured memories of Bo Jackson and the career-ending hip injury he sustained playing football. Thankfully for Ross, his injury, while serious and a cause for concern both in the short and long term, was quickly seen to and resolved, leading him to recently receive clearance to participate in all spring-training activities with the Arizona Diamondbacks.
Instead of diving head first when I tripped, I decided, the bag was right there, I was just going to try and reach for it," recalls Ross during a 3TV interview at Salt River Fields. "And when I did, my knee hyper extended and all the force went out my hip and dislocated it.
From research of available information, the diagnosis was apparently a complete posterior dislocation of the right femur with a fracture of the posterior wall of the acetabulum, the hip socket in which the femur rests within under normal circumstances. This is thought to be the first of this injury type seen at the MLB level; hip dislocations are rarely seen in sport, with most cases occurring in high-energy impact athletic events, such as rugby and football. Hip injuries more commonly seen in baseball include injuries such as tears of the hip labrum—the cartilaginous and fibrous aspects of the acetabulum—as well as impingement of the femoroacetabular joint and arthritic conditions.
For Ross, immediate treatment of his dislocation included imaging studies to identify and determine the type and severity of the dislocation, while also ruling out a fracture. Reduction of the femur back into the acetabulum is also performed as soon as possible, in order to reduce the potential for additional damage in the form of damage to the sciatic nerve, which supplies motor innervation to the posterior portion of the thigh and the lower leg and sensory innervation to the lateral aspect of the leg and most of the foot. Reduction can be performed either 'closed' or 'open', with open requiring a surgical procedure. For Ross, doctors were able to perform a closed reduction soon after his injury, with follow up surgery to repair his fracture, which included instrumentation placed to further strengthen the fractured area.
As horrific an injury and rehabilitation as Ross underwent, he appears to be well on track to having a full return to baseball activities. What biomechanical aspects of batting and throwing could be at risk as he mounts his comeback in 2014? Will he be the Ross of old, or will there be particular aspects of his game that he might struggle with as he gets back up to game speed?
Ross is an interesting subject, due to his split-handedness and throwing left, but batting from the right. This idiosyncrasy will put the repaired right hip in different biomechanical positions of dominance and non-dominance that a more traditional left/left or right/right player would undergo.
With Ross being a lefty, his right hip and leg will lead. In the prep phase of throwing, which entails a shuffle step and a setting of his feet in order to step towards his target, his body perpendicular to said target. In this phase not much weight-bearing is required of Ross' right hip. With striding, his right leg and hip will go through a move of open-chain adduction-internal rotation to abduction-external rotation via an arc of flexion. Simply put, the hip and lead leg will start inward towards the body and the move outward and away from the body in an arc as a stride is initiated. At foot plant, the right hip/leg will bear 100% of body weight and will then become a stabilizer, creating a fulcrum allowing rotation of the pelvis and then the torso and upper body as the throw is attempted. Upon release of the throw, the right hip will then endure increased internal rotation, flexion, and adduction, as it works to decelerate to the body.
While the mechanics and anatomy involved will remain somewhat similar to what was discussed with throwing, Ross' split-handedness puts his repaired right hip in a dominant, or trail leg, position, which puts different stresses on the joint than what is seen in non-dominant joints.
With his stance, his right hip will bear most of the body weight; in particular, 100% of his weight will be on his back leg, as a coiling phase which includes a slight rotation of the torso and pelvis away from the pitcher continues the swing. As Ross accelerates his swing as his left lead leg strides towards the pitch, all of his body weight will be on his right hip and leg. Upon foot strike post-stride, a large rotational force is generated at the pelvis, with a quick transfer of weight commences, with roughly half of Ross' body weight now on the right hip. External rotation and abduction at the right hip will occur at this point. Also at this point and at maximal stride length, both hip femoroacetabular joints will move inwards and will be typically at their maximal range of abduction. With follow-through, the right hip and leg will return to a more neutral level of rotation, with the right leg remaining in extension.
Running the bases will be a particular point of interest in the recovery process for Ross. Since running the bases involves quick lateral movements, especially when at first base, the crossover step will be of particular importance to Ross, since much of the action needed to initiate the crossover will originate from the right hip and leg. In particular, pelvic rotation towards the right side with concomitant push off from the left leg in an effort to move the body towards second base could be possibly a contentious task. Further adduction with internal rotation and extension of the right hip will also occur, as the lead hip turns and pulls the trail leg into position to engage a normal running stride and sequence. Similar motions are also used in the outfield in order to get to balls hit quickly to either side of the player.
With these in-depth biomechanical aspects of baseball in mind, what will 2014 potentially look like for Ross?
From a batting perspective, the injury and any potential setbacks due to pain or lack of flexibility or strength could lend Ross to a drop in power. Not only could tenderness of the area have Ross not want to plant or bear all of his weight on his back leg as he initiates pre-load, any misgivings related to strength or flexibility might also preclude Ross from complete hip rotation through the swing phase. Not only could this limit the amount of hard contact, this could also lead him to being susceptible to hard stuff on the inside corner, especially against righties, as his ability to 'throw' (externally rotate and abduct) his hips and create room for his swing path could be minimized. A look at Ross' whiffs per swing show a slow progression of his difficulties in getting to hard stuff inside and especially up in the zone.
The zone profile on the left shows Ross' percentage of whiffs per swing in between 2007 and 2012 against hard pitches from righties; the profile on the right shows the same information only from his abbreviated 2013. As the profiles show, Ross' ability to turn on hard stuff on the inner portion of the plate had already been waning before the injury; any setbacks arising from the hip issues could exacerbate and speed up the process even further. Any potential issues related to hip pain could also create an issue with Ross hitting more off his his front foot, which could potentially leave him susceptible to offspeed pitches and a lot of off-balance swings and misses.
Throwing-wise, Ross has never had a cannon of an arm, so any nagging effects arising from his hip are less of a concern here. However, pain could create issues with planting and quickly throwing on balls in the gap, creating potential problems further up the kinetic chain, leading to arm problems.
In the field and on the basepaths, running could be problematic and any issues in the rehabilitation process could be more visible in this arena at first more so than some of the other aspects playing baseball. A quick first step, be it of the crossover variety or otherwise, could be hampered by limitations in range of motion of the hip or by tenderness, which could slow Ross down. This slowing down could create issues not only with baserunning, especially at first base, where the cross over step and the 90 degrees rotation of the body and explosive first step towards second are crucial to not only basestealing but also taking the extra base, but also in the field with balls in the gap. Ross split most of his playing time last season between right and left field; with this injury any balls in the gap might give him headaches, but it would be imagined that gap hits in right-center field as a rightfielder could cause issues should his hip not be fully healed.
Overall, Ross' upcoming season will be a crucial one in the long term process of his recovery from such a devastating injury. While all signs point to his being ready for the season, the biomechanical complexity of the hip and severity of the injury all lead to a cautious outlook on the ultimate success of the upcoming season for Ross. With some help from medical advances and a better understanding and awareness of hip injuries, Cody Ross should still be able to perform at the MLB level. However, it should not be at all surprising to find his productivity to be diminished as compared to recent years even in light of his increasing age, with less power and explosiveness possibly unfortunate ramifications of his injury.
Zone profile data courtesy of Brooks Baseball.
References: Dines, Joshua S. Sports Medicine of Baseball. Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins, 2012. Print.