PELVIS AND HIPS
We can think of the pelvis and hip as the chassis and the tires of the car. The pelvis is the foundation and hips help to turn and control our car.
Pelvic control is the foundation of all patterns within the body; the pelvis is the base to our tower. Developing the ability to control the pelvis should be a priority for efficient overhead motion. Pelvic stability should revolve around the rectus abdominus, obliques, and gluteal complex. This allows the lower body to rotate independently from the upper body during hitting and pitching. It is critical for optimal power transfer from the lower body to the upper body. This creates proper hip to shoulder separation.
A decrease in hip mobility that occurs over the course of the season can cause compensatory movement patterns as well as stress on the front of the shoulder and elbow when throwing. A study published by the American Journal of Sports Medicine showed MLB pitchers who required TJ surgery were found to sustain a higher frequency of groin and hip injuries before and after surgery than the control group. The association to TJ surgery is not always the resulting hip-related injury but it’s the build-up process that manifests as a result of them.
The hips of a pitcher are subject to loss of internal rotation mobility (moving inwards) especially in the front stride leg. Athletes need adequate and range of motion and strength of stance hip’s internal rotation and stride hip external rotation (moving outward) for ideal timing of trunk rotation to square to home plate. Saito et al, found that youth baseball players who complained of elbow pain demonstrated a decrease in hip internal rotation. Furthermore, pitchers who lacked hip strength were unable to effectively stabilize and absorb force of the knee of the lead leg or apply force into the ground with the drive hip. Pitching with an unstable base decreases force production, drops velocity, and increases stress on the arm.
Loss of hip internal rotation in the lead leg to potential arm issues:
· Poor deceleration pattern – When an athlete does not possess the ability to continually rotate into their front hip after ball release, the shoulder and elbow have to slow down the arm rapidly (think of the arm slamming shut repeatedly). If an athlete can possess the proper internal rotation in their lead leg, it buys them more time to slow their arm down which will reduce the amount of stress being put on their shoulder or elbow.
· Transfer of force to the upper half (post-up) – When an athlete cannot Internally rotate into their front hip, it presents a possible issue in the “transfer of force”. Once foot plant occurs, the power must transfer force from the lower half to the upper half. Poor internal rotation into the front hip can put the hip in poor position to accept force and result in leaking energy. This can potentially leave velocity on the table.
· Pitchers with limited hip range of motion tend to land with an open-shoulder position at foot contact. This landing position results in the pelvis rotating towards home plate too early. This throws off the timing of the pitching delivery and leads to an over-reliance on the arm for force production since the energy generated from the pelvis has been dissipated. The hip and shoulder open at the same time, like a gate. Not only is this an inefficient way to throw a baseball, but it also leads to increased stress being placed on the throwing shoulder and elbow.
Loss of internal rotation does not only affect our pitchers, but our hitters as well. This can contribute to improper loading of the back hip during the negative mode or to support and stiffen up our front hip after heel plant. This robs the hitter of power.
Recent literature has focused on the importance of hip abductor muscles. The “side hip muscles”, contribute to single leg balance and dynamic control of the trunk and legs. The act of pitching is a series of single leg balances on each leg done repeatedly throughout a game. Specifically in pitchers, hip abduction weakness has been related to increased movement of the leg and pelvic regions during dynamic single leg activities. These deficits could translate to altered pitching performance and injury. Greater than 5% difference in hip abduction strength has been shown to be a correlate to shoulder and elbow injuries in pitchers. Decreased hip strength and range of motion (ROM) may limit stride distance and lead-leg positioning. This will impede the overhead athlete from being able to generate the necessary torque from the pelvis/hip and in turn transferring the torque requirements to the upper extremity.
An 18 year study Injury Trends in Major League Baseball from 1998-2015 showed hip, leg and foot injuries account for 31% of total time lost due to injury. A study by Kibler calculated that a 20% decrease in energy delivered from the hip and trunk to the arm requires a 34% increase in the rotational velocity of the shoulder to generate the same amount of force to the hand. This makes a significant case for proper rehabilitation and care to these injuries, even minor “tweaks” and their long-term impact on shoulder and elbow health and durability. Kibler et al proposed that inadequate hip ROM and poor balance may significantly affect an athlete’s ability to transfer energy along the kinetic chain, resulting in dysfunctional movement and increased stresses on the shoulder and elbow.
Our home-grown S.C.O.R.E. movement screen can identify areas of tightness or weakness in the hip as well imbalances between the right and left side. Mobility exercises will always be prescribed before strengthening exercises. Often low load unilateral exercises are needed with end range focus are needed for our pitchers. With our often fast-growing male athletes, muscles around the hip such in the hamstrings can get tight quickly.
I hope you enjoyed this off season round up on mobility and strength. Our next topic will be on WEIGHTED BALL!