Physical Limitations Expressed in a Hitters Swing: Identifying "drift" in a hitters swing
When we talk about physical limitations, we're talking about impairments that affect how an athlete swings at the plate. There are some components that are present in an athletes swing that universally would be seen as being “faults”, but the player is so consistent with this style of swing that they are successful using it. For the sake of this blog, we aren't referring to these hitters. OnBaseU believes that through various points of the swing we can take snapshots and use basic biomechanical principles that are specific to that segment of the swing, and also, is consistent with the majority of great hitters. The question posed is when we visually analyze a fault in an athletes swing, are the characteristics we see in his/her swing because of their style, therefore, technique or because there are physical limitations that force that athlete to compensate? What happens to athletes that keep doing the same thing even after coaching and cueing?...
Drifting, which is basically identified from first movement of the hands toward the pitcher and includes everything up until contact. In figure 1, you can see the red line that is present on the front hip, and after movement towards the pitcher and until contact, we don’t want to see the pelvis move in a linear fashion past this line; if it does, it suggest there is a drift present.
Figure 1: Visually analyzing drift in the baseball swing
What does a drift mean in the swing? To get a better understanding of this concept, lets first look at how a hitter generates power. In order to produce the most possible force, we use what’s called Ground Reactions Forces (GRF), this is generated by planting the front foot into ground (using Newton’s third law, force exhibited on an object will reciprocate an equal and opposite reaction) that moves up the chain and is then amplified by the biomechanics of hips, torso, arms and bat until finally transferring to the ball at contact. If the athlete isn’t staying true to these mechanics (in the form of a drift), then they are losing power and above all adding more moving parts to an already complicated movement; decreasing the consistency from swing-to-swing.
If there is a mechanical limitation in the athlete, then it will present itself in three different forms we analyze an athlete, first one being the video analysis, second is a physical screen, and the third is 3D motion capture. Since we’ve already established a drift with video analysis, we can then move on to the physical screen, which assesses the physical competency with which is required for this segment of the swing. Limitations that would present themselves as a drift in the swing would be identified in the movements exhibited in figure 2 and 3, figure 2 is analyzing the internal rotation of the front hip and figure 3 is assessing hip stabilization. From this point we ask two questions, which is, can the athlete perform the movement and do they meet the criteria we set for each movement; this decides whether or not further physical investigation is warranted.
Figure 2: Internal rotation of hip
Figure 3: Stabilization of left side of the pelvis
The third way we can assess drift occurring with an athlete is to assess the energy produced by each body region and the transfer of that energy from segment to segment, this is known as 3D motion capture. 3D motion captures allow us to see how deep this swing fault goes, which simply means attaching body sensors on the athlete and assessing the acceleration and declaration of those sensors (body segment). Figure 4 represents the kinematic sequence of an athlete and the red line represents acceleration/deceleration of the athlete’s pelvis. The curve circled represent the deceleration of the pelvis or the transfer of force from the hips through to the torso. What we see in great hitters is after the peak of the deceleration of the pelvis, there should be a sharp decline in this curve. Hitters who have a drift have an insidious deceleration after the peak and not as a drastic decline like we want. This basically means that there is an energy leak present, due to the physical limitation or technique deficiency.
If the athlete has a physical limitation that is causing the drift, then it will be apparent on all forms of assessments, the video analysis, physical screen and ultimately the 3D motion. The best way to address a physical limitation is by joint mobilization/manipulation to the hip or ankle, muscular release, and/or introducing stabilization to the region. Coaching or cueing an athlete for a drift with this type of physical limitation will more than likely cause the athlete to compensate in other means, because he/she does not have the physical competency to perform the movement; thus will seek other strategies to accomplish the movement. After we’ve taken care of the physical limitation, then we can start addressing the technique and cueing with the hitter to properly integrate the once physically limited region back into the swing.
Figure 4: Deceleration or transfer of energy from the pelvis to torso
I can tell you that I wish I had this as an athlete growing up… The detail is unparalleled to anything I have seen and making is accessible to athletes that aren’t responding to technique ques or just want to get an overall report of how they hold up against what is suggested as biomechanically sound movements in the sport they perform is what I’m trying to do. If you have any questions on the topic or just want to discuss this in further detail, you can email me at drdakota@focusonhealthchiro.com or DM me on any of the social media platforms I have. Thank you and happy swinging!
Dr. Dakota