“” Using PULSE to guide phases of throwing rehab - Driveline Baseball

Using PULSE to guide phases of throwing rehab

| Blog Article, Pitching, Pulse
Reading Time: 8 minutes
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Previously, with case studies such as Troy Rallings, we explored using data and technology to tighten the feedback loop in the rehabilitation process for throwers. Throughout Troy’s rehab we monitored his workload and elbow torque as measured by PULSE (then Motus) to ensure he wasn’t being stressed too aggressively, too fast. 

Today, with PULSE, we’re able to provide athletes with unmatched feedback about their throwing fitness and intensity to help them get back in shape and ready to compete. The information from PULSE allows for clear expectations and guidelines for each phase of the return to throw process — insights you can’t get from throw counts alone. 

Using PULSE as a prescriptive tool

This previous winter, we had a professional athlete named Ezekiel who was going through the rehab process. (Not his real name. But it sure would be awesome if it was).

For Ezekiel, we aimed to use PULSE as a prescriptive tool to aid in the rehabilitation process, rather than just a monitoring tool. This was our first time attempting to use PULSE as a prescriptive tool in the return to throw process. For this reason, it is worth mentioning that we predominantly applied additional prescriptive boundaries to the existing programming being used by our rehabbing athletes – courtesy of our DPT Terry Phillips. 

The main goal with any rehab program is to safely return the athlete to competition mode by building throwing strength and fitness — or chronic workload. In Ezekiel’s case, we hoped that his program would look something like the graph below. The graph below shows the planned one-day workloads (the bars) with the chronic workload (the line) overlaid. We see varying amounts of one-day workloads, while the chronic workload steadily increases. 

We settled on tracking the following criteria to make that happen: 

  • Amount of Throwing
  • Intensity of Throwing
  • Frequency of Throwing
  • Progression of Throwing Volume
  • Progression of Throwing Intensity
  • Expected “Stress” Based Upon Pre-Injury Information

Using the above criteria, we were able to build out phases for Ezekiel, each with a clear goal and purpose to help him get back in throwing condition. 

Throughout the rehab process, iterations upon this schedule were made but the rough framework remained the same.

Phase 1: Initial Return to Throwing (6 weeks)

Primary Objective – Increase throwing frequency.

During the initial phase, we collected baseline torque and velocity readings in order to establish guidelines for future “stress caps” and one day workloads. “Stress caps” were meant to serve as an intensity threshold for each throwing session. 

From there we increased Ezekiel’s workload by introducing more frequent throwing sessions. We started by prescribing 3 sessions a week, then 4, until Ezekiel was throwing 5-6 times per week. All sessions were at or close to his stress cap and one day workload target. 

Because there is some normal fluctuation in these metrics on a throw-to-throw basis we selected a small bandwidth for each day that was then translated into a velocity range that Ezekiel would follow. 

Intensity and one day workload were monitored closely, but they weren’t the drivers of the throwing program.

Phase 2: Increasing Daily Throwing Volume (8 weeks)

Primary Objective – Build throwing fitness by increasing throwing volume

Now that Ezekiel was throwing most days of the week, we introduced additional throwing volume to help him build throwing fitness. 

One day workloads were progressively increased by adding throwing volume as opposed to intensity, which stayed around his previously established stress cap. Throughout this phase, intensity and one day workload values were prescribed.

Phase 3: Developing “Arm Fitness” (6 weeks)

Primary Objective – Build chronic workload by increasing throwing intensity

Phase 3 is an extension of the previous phase, but instead of further increasing throwing volume we started to increase intensity. 

During this phase, we began to progress the peak stress Ezekiel experienced in his higher intensity throwing sessions until he was back at his average stress levels before surgery. At the end of this phase, Ezekiel was fully onboarded to the point where we wouldn’t treat him any differently than other healthy athletes. 

Phase 4: “Traditional On-Ramp” (8 weeks)

Primary Objective – Return to normal throwing programming

As noted above, Ezekiel had just started working at throwing volumes and intensities close to his previous baselines, but wasn’t doing so multiple times per week. The goal of this phase was to get him working at those levels regularly every week. 

During this phase, peak stress and average stress incrementally increased. To account for this, we kept his chronic workload consistent, if not slightly lower than than the previous phase to avoid overworking Ezekiel. From there, intensity and one day workloads continued to increase incrementally.

This phase is typically the last phase of our in-house return to throw program and serves as an extended on ramp back into traditional throwing programming. At the end of this stage Ezekiel was fully rehabbed and ready to compete.

Phase 5: Return to Velocity Training (6 weeks)

Primary Objective – Prepare the arm for consistent high intensity throwing.

Ezekiel had consistently been throwing at maximum intent on a regular basis. He had successfully returned to a confident level of throwing fitness and had also been exposed to stress levels similar to what was expected based upon their previous level of competition. 

At this point, Ezekiel was technically prepared to return to competition. However, a common trend we see in post-op athletes is that they have a hard time throwing at truly max intent, so we opted to put Ezekiel in a velocity building phase. 

The velocity building phase is intended to get athletes used to throwing at maximal intent on a regular basis. Similar to the previous phase, chronic workload decreased slightly at the beginning of the phase to account for the increase in throwing intensity. 

Following this phase the athlete was fully rehabbed and ready to compete.

What Comes Next?

It depends! At the conclusion of Phase 5, Ezekiel returned to his organization. Other athletes may have more time before needing to report to camp and can spend time in a competition- or pitch design-focused stage depending on what their needs are. At the end of the day what matters is that the athletes are fully rehabbed, fully onboarded, and ready to compete. 

The key advantage to using PULSE in this data-driven approach is that it eliminates any biases or uncertainty in programming, allowing the athlete to progress based on when his body is saying, rather than simply following the program and guessing. 

Since returning to his organization, this athlete has begun throwing live to hitters again and is throwing his fastball in the mid-90’s, reaching as high as 96 miles per hour.

What’s This Mean for the Future of Rehab at Driveline?

This was an extremely important learning experience for us at Driveline. We had used PULSE to monitor the rehab process before, but never to directly drive programming with it. Building on the workload-driven rehab programs by Ben Hansen and Weston Germain we were able to successfully monitor and prescribe return to throw protocols for Ezekiel. 

Being able to leverage data and tools to improve upon the rehabilitation process within baseball is something that we hope to continue to push forward. From Ezekiel’s rehab, we had the following takeaways:


  • We can build towards the demands of competition using PULSE
  • We can distinguish between varying intensities and workloads throughout the rehab process
  • We can make alterations to the plan when/if setbacks, weather, etc. interfere with the original plan


  • Athletes can become “victim” to the data (scared to push too far)
  • It’s not always feasible to have live data within the rehab setting

The good goes without saying — by using a methodical approach founded on tracking workload with PULSE we were able to create a more effective rehab program. 

The bad leaves us with room for improvement. It’s essential that the athlete understands that the throwing program is designed around how they feel. As they start to get comfortable throwing again, it’s actually encouraged that they start to stretch their throwing velocity and stress levels. 

Additionally, mapping velocities to stress levels for the athlete can help limit the need to track throws live. 

We also picked up some good ideas for future iterations of the rehab program: 

  • Prescribe ball weights in accordance with arm stress/ arm speed guidelines
  • Monitor throwing fatigue units. Rest between throws and sets of throws

It would certainly be inappropriate to conclude that Ezekiel’s rehab program is the definitive way to handle a rehab throwing program, or that no further iterations should be had. Applying additional criteria onto our existing return-to-throw framework provided us with additional insight into the good and bad of the current system, as well as identify areas to improve for the future.

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