Arm Assessment for Velocity Programs

Velocity, accuracy and durability. These are the characteristics that set a pitcher up for success. Without any one of these characteristics, the full athletic potential of a player will be missed. So what is the best way to maximize each of these? The answer is to utilize an assessment based arm care program regularly to identify impairments, fatigue and shortcomings of each individual athlete. Without testing, you’re just guessing.

Velocity development programs (Velo programs) are one of the most common training protocols being utilized by coaches across the country. These programs often utilize weighted balls in an attempt to optimize throwing efficiency, train arm speed and increase passive external rotation during layback to collectively increase throwing velocity.

But how do you know if an athlete is ready to participate in a velo program? How do we maximize the benefit of the velo program for each athlete? How do we reduce the injury risk during a velo program? The answer, utilize an evidence based pre-velo screening tool as a part of your assessment based arm care program.

Research has consistently highlighted a number of modifiable risk factors that predispose a pitcher to an increased risk of injury. Each of these risk factors should be assessed during a pre-velocity screen. 

Below are a few of the arm diagnostics that the Arm Care Pre-Velocity Screen will evaluate to determine a player’s readiness to participate in a velocity program. In addition to the objective evaluation, we have also provided a checklist of additional considerations that should be followed prior to starting a velocity program.

IR Strength

Internal shoulder rotation strength (IR Strength) helps to accelerate the arm toward the target and also provides stability to the shoulder as the internal rotator muscles lengthen to slow down layback of the arm.

IR strength is shown to be one of the biggest influencers of throwing performance. Pitchers often have greater IR strength on their dominant arm compared to non-dominant arm, as well as increased IR strength compared to non-throwing age matched individuals.

If your internal rotation strength is in the bottom 25% of your age group, you will benefit from additional strength work prior to starting a velocity program. By following your recommended arm care program and training, you will address this underlying weakness, reduce your risk of injury and likely experience greater performance gains than you would if you jumped into a weighted ball program.

ER Strength

External rotation or posterior cuff strength is responsible for controlling the ball in the socket during layback as well as the deceleration of the arm after ball release. 

Preseason weakness has been shown to be one of the strongest predictors of throwing injuries in the shoulder as well as the elbow.  In fact, athletes that suffer Tommy John (UCL) injuries have demonstrated a 30% decrease in their ER strength tests prior to their injury. 

Based on the overwhelming body of research linking ER weakness to injuries in throwing athletes, if your strength falls in the bottom 25% of your age group, your focus should be on a posterior cuff strengthening program rather than a velocity program at this time.

Scaption Strength

Scaption strength plays a key role in shoulder stability and the ability to transfer power during the throwing motion. During the course of a season, or following heavy workloads, scaption strength has been shown to decrease by 13%.  In addition, pre-season scaption weakness was a strong predictor of in-season injury.  

If your scaption strength test is in the bottom 25% of your age group, you are risking injury and decreased accuracy due to poor control at your shoulder joint.  Take time to focus on strength and improve your mechanics prior to starting into a velocity program.

IR Symmetry

Internal rotation strength has consistently been shown to be stronger on the throwing side, compared to the non-throwing side in healthy shoulders.  This IR strength gain is consistent across age groups (high school, college, and pro) and ranges from 5-15% stronger. 

If your throwing arm internal rotation strength is significantly weaker than your non-throwing arm, it could be an indicator of fatigue and needs to be restored prior to starting a velocity program.

ER Symmetry

External rotation strength symmetry findings in the research have been mixed, with some studies showing stronger dominant arm, while others show a weaker dominant arm, while even some others show the differences between sides are not statistically significant.  Taking the literature as a whole, it can be extrapolated that ER strength symmetry should be within 10% in either direction.

If your throwing arm external rotation strength is significantly weaker than your non-throwing arm, it could be an indicator of fatigue and needs to be restored prior to starting a velocity program.

ER/IR Strength Ratio

In addition to an athlete’s raw strength numbers it is important to make sure their strength remains in balance.  The nature of throwing mechanics as well as a high volume of pitches naturally increases a pitcher’s internal rotation strength.  However, if there is a lack of increased external rotation strength to counter the internal rotators, athletes end up with an increased risk of injury. 

Research has focused a lot of attention to the ER:IR strength ratio and the role it has in risk of injuries to the rotator cuff, labrum and UCL.  If you have greater than a 20% difference between your ER and IR strength, you are at an increased risk of injury, and not appropriate to begin a velocity program at this time.

Scaption Symmetry

Scaption (Supraspinatus) strength symmetry: In throwing athletes, weakness of the supraspinatus muscle is strongly linked to an increased risk of injury.  But despite a pitcher having a dominant side, research indicates that there is no significant difference in supraspinatus strength between dominant and non-dominant sides.  

Anything greater than a 10% difference in limb symmetry should be examined further and corrected prior to starting a velocity program.

Internal Rotation Range of Motion (ROM)

The internal rotation range of motion of the shoulders is often asymmetrical, with less internal rotation occurring on the throwing arm. These changes are often normal adaptations to throwing, but may also be a sign of restrictions developing in the arm. A loss of internal shoulder rotation is commonly called GIRD and currently defined as a loss of more than 20° of internal rotation on the throwing arm compared to the non-throwing arm. Research shows a significant loss in internal shoulder rotation after pitching, which can accumulate throughout a season if it’s not caught or left unaddressed. These changes can alter the biomechanics of the shoulder and increase the risk of injuries like labrum and rotator cuff tears.

External Rotation Range of Motion (ROM)

Baseball players often have greater external rotation range of motion on their throwing arm. In fact, research defines a pitcher having ER Deficit if their throwing shoulder doesn’t have at least 5 degrees more external rotation than their non-throwing arm. This is a normal and protective adaptation to throwing. Pitchers who have ER Deficit have a moderate increased risk of shoulder injury, and a significant increased risk of elbow and UCL injuries.

Flexion Range of Motion (ROM)

Shoulder flexion range of motion is an important factor when looking at injury risk. Baseball players should have the ability to bring the arms all the way overhead and should be symmetrical between the right and left sides. In fact pitchers with shoulder flexion deficit in their throwing arm greater than 5 degrees was determined to be the most significant categorical risk factor associated with increased elbow injuries. Your arm care needs to focus on shoulder mobility and range of motion at this time rather than starting a velo program.


Indicated through decreasing trend of strength & ROM.

Strength Fatigue Trends Fatigue is the number one predictor of injury in baseball pitchers. Pitching while the arm is fatigued results in a 36x increase in the athlete’s risk of injury. By closely tracking your strength numbers through your assessment based arm care program, you will be able to pick up trends of decreasing strength if fatigue is present. It is not the right time to start a velo program when your arm is fatigued, and your strength values are trending down.

Shoulder ROM Trends – Acute changes in shoulder range of motion can be indicative of fatigue. Fatigue is the number one predictor of injury in baseball pitchers. By closely tracking your range of motion through your assessment based arm care program, you will be able to pick up trends of acute or progressive changes indicating fatigue or early injury is likely present. 

Velocity Checklist

If you pass the Velocity Screen that is great. But just because your arm checks out, does not mean that you are ready or it is the right time to start a velocity program. Below is the Velocity Checklist that you need to pass prior to beginning a velocity program:

  • 1. You have never experienced an injury that required surgery – If you have experienced a prior surgery to your arm; a velocity program us bit advised as it is possible that you could have a secondary injury where surgical outcomes are not as favorable. If you have had a previous surgery; please consult your orthopedic surgeon prior to beginning a velocity program.
  • 2. If you do experience arm pain – Hopefully this is an obvious point. You never want to throw through pain. If you do experience arm pain; communicate with your coach and STOP THROWING.
  • 3. You are not in-season – During the season; your goal is to properly manage your workloads and recovery periods so that you feel fresh and strong. This is not the time to do a velocity program. Typically velocity programs are done in the off-season training period or the pre-season (60-80 days before the season begins).
  • 4. Have been throwing consistently for at least 6 weeks – You need to build a base of throwing prior to engaging in any Velocity Program. Six weeks is the bare minimum. This base also known as chronic load will better prepare your soft tissue for the forces it will encounter during the velocity program. To ensure your arm has had suitable amount of work; it is recommended to start velocity programs after bullpens have started in your throwing program. You do not run and gun before throwing off the mound.
  • 5. Have taken time off if your workload was high last season – If you have had a heavy throwing workload last season (80 or more innings); you need to take a minimum of 2 weeks to a maximum of 4 weeks off of no throwing and do not feel fatigued or sore when playing catch.
  • 6. Baseline Physical Condition – You will need to build a foundation of strength of at least a year prior to the start of a velocity program. The following are recommended physical benchmarks to achieve prior to beginning a velocity program that can be assessed by a qualified strength and conditioning professional:
    • a. Able to squat your body weight for 6 reps

    • b. Able to lunge with half your body weight for 6 reps each leg (Example: if you weight 200 lbs.; you should be able to lunge with 100 lbs. of resistance; meaning you will have 50 lbs. dumbbells in each hand)

    • c. Able to press 80% of your body weight for 5 reps (Example: if you weight 200 lbs.; you should be able to press 160 lbs.; meaning you will have 80 lbs. dumbbells in each hand)

    • d. Vertical Jump should be over 28″

    • e. Can hold a plank for 3 minutes

    • f. Can perform 6 continuous pull-ups with a 1 second pause at the bottom

    • g. You are sprinting at least twice per week

  • 7. Baseline of arm care (minimum 3 months) – You need to build a strong and stable foundation around your arm; prior to starting a velocity program. This can be accomplished by following the assessment based arm care in the app. Arm Care will help protect your arm from injury as well as aid in throwing velocity. Research has shown that arm care can help you increase velocity by 2% – 4%. In using the Arm Care app; you should meet the following strength and range of motion requirements prior to beginning a velocity program:
    • a. External Rotation: Internal Rotation Strength Ratio between 0.85 – 1.0 (if you are too low; you need more external rotation strength. If you are too high; you need more internal rotation strength)

    • b. External Rotation and Internal Rotation Strength that are both greater than 25% of your body weight

    • c. Grip Strength greater than 15% of your body weight (Arm Care Grip Strength Test)

    • d. Total Shoulder Arc of Motion with 10 degrees difference between throwing and non-throwing arm

    • e. Throwing arm has at least 5 degrees more external rotation than the non-throwing arm

  • 8. Have a qualified coach designing & monitoring your program – You need the guidance of a coach who has a successful track record of conducting velocity programs with positive results. Meaning players are increasing velocity and staying healthy during and after these programs. Effective programs are generally at least 7 – 8 weeks long and heavy throwing days are spaced out by 72 hours of recovery work.
  • 9. Your throwing mechanics are efficient – Throwing mechanics need to be analyzed on slow motion video and determined to be reasonably efficient by your coach. An additional aspect to review in evaluating efficient mechanics is your strike percentage. Your coach should be able to determine if your strike percentage is consistent successful for your level of competition. If you are not consistent in your mechanics; your involvement in a velocity program may expose you to increased injury risk and actually hurt your performance as you may throw harder; but unable to command the baseball.
  • 10. Nutrition & Sleep are essential – Nutrition & sleep are critical in promoting recovery. This is especially important when participating in a velocity program. Nutrition & sleep will not only have an impact on the health of your arm but will also aid in your velocity development. In addition to sleep and nutrition; be educated on other forms of recovery for your throwing arm such as the use of a MarcPro; Compex units or other recovery devices that help control inflammation. Do you best to avoid ice as it may delay recovery. If you continuously ice your arm; you may be experiencing chronic pain and should consult a medical official. If out of habit; consider other alternatives.
  • 11. Understand & acknowledge that there are risks involved – Whenever you push yourself to your physical limits; there are risks to acknowledge. The velocity program checklist and Arm Care app is designed to ensure you are physical ready for the program and extensively monitored. However; you have to determine if you are psychologically ready for a velocity program. If you have doubts; it is a good idea to consider other programming alternatives; as your mindsets is as important to success as your body in a velocity program.
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