Putting on the Brakes to Throw Gas… What is Lead Leg Block?

lead leg block

The lead leg block is the act of slowing down your body’s momentum with your lead leg at landing. In biomechanics, deceleration and the lead leg block can be represented by peak changes in angular velocity. Think about your car. The gas pedal represents your drive leg at the start of the pitching delivery (power output) and the brakes represent your lead leg’s role at foot contact (power absorption and transfer of force).  Let’s cover this in three parts:

    • Why is it Important to be Good at Decelerating?
    • What We Look For?
    • How We Address Lead Leg Block Issues?

Why is it Important to be Good at Decelerating?

Going back to the car analogy. Do you want to be driving around a car that has no brakes? The obvious answer is no. With poor brakes (lead leg) you can’t slow down safely and over time you end up causing wear and tear to the surrounding joints and ligaments because they are now handcuffed into absorbing excessive forces that they are not meant to handle.

The ability to decelerate (great brakes) is essential for protecting pitchers and players from high magnitudes of forces experienced on the mound and/or field. In the literature, it has been supported that a high incidence of non-contact lower extremity injuries such as ACL tears and ankle sprains occur during eccentric muscle actions (sudden pivots, landing and decelerating).

Being able to distribute force away from the ligaments such as the (UCL and ACL) and properly disperse them throughout the tendons and musculature could significantly contribute to increased throwing velocity as well as adding to the longevity of an athlete’s career.

What We Look For?

Pitching is one of the fastest motions in all of sport. So, it’s important to evaluate any movement pattern from multiple different viewpoints.  With respect to decel, we look at the following:

    • Kinematic Sequence
    • Braking Ability
    • Lead Leg Blocking

Kinematic Sequence – The human eye paired with the use of motion capture technology is a great place to start to examine both the kinetic and kinematic forces that occur during the baseball pitching, hitting, and even change of direction. With this technology, we essentially can see how smooth and efficient an athlete’s braking ability is.

lead leg block

Braking Ability – When it comes to assessing athletes braking ability, here are 2 questions to keep in mind:

    • Question 1 – What is this athlete’s relative strength and force absorption capabilities?
      • Relative strength = Absolute strength / bodyweight
      • If their relative strength is low focus on increasing strength and implementing force absorption exercises

(1-Leg Snap Down w/ Med Ball)

    • Question 2 – How quickly and how much of this force are they able to absorb (rate of force acceptance)?
      • Are they able to maintain strength and posture within all joints as ground contact is made?
      • Keep in mind research has shown that athlete demands in sport occur at or less than .250ms for sagittal plane movements and .300ms for frontal plane movements.

To learn more about how to maximize reactive strength click here.

Lead Leg Blocking – Two pieces of information we look at in the pitching delivery are knee flexion angles at foot contact and lead knee extension angular velocity at ball release (how fast the knee angle changes). In athletes who struggle with force acceptance, you’ll most likely see them sink into their front leg increasing knee flexion angles, and be late posting up. This is commonly associated with lower pitching velocity.


On the other hand, Dr. Fleisig among other preeminent researchers in the field have noted that pitchers who were able to generate a higher ball velocity also demonstrated faster lead knee extension angular velocities greater than 250 deg/sec. With these athletes, you will see them continually extending after foot plant.

How We Address Lead Leg Block Issues?

The SSC is what gives the athlete the ability to quickly switch from eccentric to concentric while producing maximal force in the least amount of time. In a sport like baseball there are specific time constraints a pitcher has to perform under.

A slow pitcher who takes anywhere from 1.5-1.6 sec (slow in and out of glute load) from the time he initiates his pitch until the ball reaches the catcher is going to have to have baserunners stealing on him all day long. On the other hand, a pitcher who is 1.3 or less (fast in and out glute load) is going to have a more effective pitching delivery and keep baserunners from stealing.

Taking a closer look into the Stretch Shortening Cycle (SSC)  and the role it plays in improving an athlete’s ability to produce, absorb and redirect those forces (flipping the switch)  we can structure an athletes training into three categories that mirror the inner lying mechanisms at work in the SCC:

    1. Plyometric and Force Application Progressions
    2. Accentuated Eccentric Loading
    3. Medicine Ball/Plyometric Work

1. Plyometric and Force Application Progressions

Due to the fact that The SSC cannot be trained with the same exercise, here at RPP, we break them into 3 distinct phases lasting 4-6 weeks.

Phase 1: Focus is developing eccentric strength deceleration and correct technique in jumping and landing mechanics.

(Heiden and Stick)

Phase 2: Focus is Eccentric strength and multi-direction work with longer ground contact times (flipping the switch) .

(45 deg Double Bound and Stick)

Phase 3: Focus is Concentric Phase with a primary emphasis of horizontal power in the frontal plane into vertical power


    • Gradually build the distance the athlete is jumping to
    • Challenge them to stick and hold this athletic position for a solid second
    • Use visual markers to give the athlete a target and move this target as the athlete starts to master shorter distances

2. Accentuated Eccentric Loading 

Eccentric/isometric training or “Tissue-Prep” is a great way to essentially “safeguard” athletes by adding more sarcomeres to the skeletal muscle and is best trained early in the off-season in preparation for any heavier work in later phases.  Adding tempos emphasizing slow eccentrics (3-5 sec) and isometric pauses (2-3 sec) helps break down the components that make up a muscle cell (Titan). In response, the body will go into “protective mode” and repair it by adding more sarcomeres to the skeletal muscle.

The more sarcomeres, more actin and myosin we have and resulting in more powerful cross bridges being formed. The extra bridges means we have developed a bigger and stronger muscle with the capability of producing more force and hopefully improving an athletes declaration pattern by being able to absorb more force as well.

Tissue Prep:


(RFESS w/ Pause)


    • Technique is everything, make sure the athlete’s posture doesn’t break
    • Stay as close to the prescribed tempos as possible

3. Medicine Ball/Plyometric Work 

At RPP we are a huge fan of using med balls because it can help athletes coordinate the proper sequence of the kinetic chain and improve the rate at which force can be accepted and transferred into a different direction (pitching).

Phase 1: Focus is proper sequence of kinetic chain with low eccentric force.

(Med Ball Shovel Pass)

Phase 2: Focus is proper sequence of kinetic chain with medium eccentric force and longer ground contact times.

(Step Back Shovel Pass)

Phase 3: Focus is proper sequence of kinetic chain with high eccentric forces and shorter ground contact times.

(Lateral Hurdle Hop to Heiden)

It’s important to note that a there is mutualistic relationship between producing high forces and the ability to decelerate against those forces under specific time constraints with a solid lead leg block. By organizing training that develops the under lying mechanisms of the SCC, athletes can reap the benefits of a highly efficient and effective kinetic chain and more efficient transfer of power to sport.

By Nancy Newell (BS, Strength Coach at RPP)

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