Mobility, Flexibility & Stability Screening

Issues present in the screen started with lack of pelvic control. T-Spine tried to activate the lower lumbar and abdominals. This is present in the swing mechanics as well and is a big part of fast energy transfer up the chain. We’ll address this as part of the warm up plan on hitting days.

Excellent hip and torso disassociation. Slight limitation in flexion and extension of thoracic spine. Hamstring flexibility was normal. Slight limitation in external rotation of both shoulders. Left shoulder was in the normal range, but slightly limited for a left handed thrower. Internal rotation of both shoulders normal. Shoulder flexion was normal as well. Scapulas strong and stable.

T Spine rotation was at 45 degrees. That’s on the low side of normal, but fine for a hitter. This shows it will be easier to take the slack out of the core. Proprioception on single leg balance was good as well as ankle stability.

Internal rotation of both hips limited. As a hitter, this is one area I don’t mind players being short. Shortens the time it takes to finish range of motion in the hip during rotation for faster energy transfer. However, right external rotation was at 40 degrees – looking for 60 degrees there.

Cervical and wrists passed in all movements.

Force Plate Jumps

Left to right unilateral balance was good in all jumps. Good to see since there is a previous history of hamstring pulls. Explosiveness in counter-movement jump was 127% of body weight. Squat jump was 145% of body weight. This would indicate a slower rate of force production up the chain and need for a longer, slower loading mechanism.

Force Plate Swings

Here is an explanation of the force plate data. Videos of force plate data combined with 3d data are below in the 3d section. Data and videos for each of the three styles will be discussed.

The strength of the set up is the back leg force numbers. I’m looking for hitters to get 90% of their body weight into their back leg load and maintain that into the forward advance. Back leg vertical force numbers ranged from 95%-100% regardless of style and were held through the positive move.

Front leg vertical force numbers varied by style and it’s an area that needs improved consistency. I look for front leg numbers to double the back leg numbers. The regular style and handsy style fell well short of that in the 155% range while the pre-set scap style held at 185%. This shows the need for a firmer heel plant, better front leg stability and the need for faster front leg extension.

The X-axis timing number is an important one for me. This shows the smoothness of the advance. I want the advance force to be under 10% body weight. It held steady at 2-3% which is outstanding. It also shows how fast energy is being transferred from leg to leg. This is the feeling of maintaining back leg tension into the turn, which was lacking some. Glute pressure was being released into landing, prior to the turn.

Position of foot pressure was consistent from the ball of the foot to the mid-foot. I usually look for mid-foot to heel on this but the back leg load numbers are so good, the need for adjustment is inconsequential. Back leg torque numbers were hit and miss. The counter rotation into the lower body load produced torque readings of over 40 Newtons which is outstanding. Those same reps, the lower body fired sooner and the swing sequences were better. On reps, especially in the “handsy” set, the torque readings were lower and the hips were more in a neutral position causing the hands to go first. This may have been the mindset in that style anyway, because of what was trying to be accomplished. But the pre-set scap reps were inconsistent. The torque of the back leg would be necessary in this style and would diminish leg production.

Video of all three styles with force plate and k-vest explanations is on the following tabs.

KVEST Sequencing & Rotational Speeds

Out of the 3 styles we tested (Regular, Pre-set Scap and Chill), the Regular swing had the best sequencing and efficiency.

Regular Style

You can see in this graph, the efficient building of the sequenced peak’s on the x-axis. Essentially this means the body parts are working in the correct order to effectively transfer energy from the ground – up the chain. Rotational speed values are average for the professional level. Most noted here is the climb between hip speed and torso speed. A 300 degree/second climb is quality. However, the exit velocity and bat speed were less in the regular style than the pre-set scap style.

Video of Regular Style

Preset Scap Style

Though the exit velocity and rotational speeds were greater, the efficiency of this style is out of sequence. Therefore, there is more bat speed left in this style. Essentially, the shoulder is turning the core instead of the hips turning the core. This is because the hips were more in a passive state without the loading mechanism of counter-rotation you have in the rhythm and load of your normal style. Because the hips are riding out in your positive move, in neutral, there isn’t as much “spring” in them and they are late in rotation. This reduces the energy transfer potential in the swing. Again rotational speed values vs. professionals are average in hip speed and “good” (2^nd highest of 5 categories) in torso speed.

Video of Preset Scap

Handsy Style

This style accomplishes the goal – it’s a “B” swing used to get to a tough pitching where the pitcher isn’t going to give up much. Hands are quicker to the ball, but jump the sequence to do it. Rotational speeds are less, but time to full speed was improved (.216 – which is in the “average” professional category). Lead arm and torso essentially turning at the same time, because scap isn’t loaded as long.

Video of Handsy Style