Biomechanics lab and wearable sensor manufacturer Motus Global has expanded its offerings for baseball players over the winter. The Massapequa, N.Y.,-based company rolled out the mThrow last spring. This year, Motus Global will sell two systems: motusPRO, a full-body system available only to professional organizations, and motusBASEBALL, a single sensor system that provides feedback for both pitching and hitting.
Originally unveiled at the MLB Winter Meetings, the motusPRO is a system of five inertial measurement unit (IMU) sensors that offers biomechanical feedback on both hitting and pitching. The IMUs combine accelerometers and gyroscopes that can be combined to estimate joint angles, velocities, and other elements of the kinematic chain.
The sensors are designed to fit into iron-on pockets on the athlete's clothing or into clips that attach to a cleat or batting glove. The sensor locations (seen here) are mostly consistent for both batting and pitching: four sensors are placed near the top and bottom of the back, on the upper arm just above the elbow, and on the inside of the cleat on the stride foot (the left foot for right-handers). The fifth sensor is placed in a pocket just below the elbow to measure pitching and clipped to the lead hand batting glove to measure hitting. The pockets are color-coded to match LED lights on the sensors, ensuring that the sensors are placed correctly.
After every pitch (or hit), the system sends data via Bluetooth to an iOS device. Dozens of metrics are computed and uploaded to a cloud server for later analysis. But a subset of eight metrics is available on the iOS app for immediate feedback, as shown in the picture below. Chief technology officer Ben Hansen says these eight were chosen because they are the data points pitchers and coaches request most often during biomechanics sessions.
"The first four give insight into 'How strong is my kinetic chain?' and 'Am I achieving timing separation in my core?'" Hansen said. "The last four are quick checkpoints that pitching coaches and the research community have found to be significant."
Screenshot of motusPRO iOS app, with one of the new sensors. Courtesy Motus Global.
Motus Global expects teams to use the motusPRO system around once per month for each player. The system's more in-depth analysis can then serve as a baseline for comparison with the single-sensor motusBASEBALL system. Hansen says this will allow teams to collect useful biomechanical data without burdening the players.
"We are a firm believer in the value of the data we provide, but we also recognize that an athlete’s job is to compete," Hansen said. "We don’t want to get in the way of that."
The simpler motusBASEBALL system consists of a single sensor worn in a compression sleeve for pitching and clipped to a batting glove for hitting. (Like the mThrow, the device will retail at $150.) Designed primarily for amateur athletes, the motusBASEBALL system replaces Motus Global's earlier mThrow device but allows capture of both hitting and pitching metrics.
The iOS apps have been updated to support the new sensors; the new versions will be available in the App Store soon. The motusTHROW app includes many of the same features as the current mThrow app, including workload and elbow torque estimates. But the new app also estimates fingertip velocity (measured in miles per hour) and elbow height.
The motusBATTING app includes six metrics for hitters: bat speed, swing time, hand speed, swing length, attack angle, and vertical angle. The hitter's performance is broken down by area of the strike zone. If a hitter's swing is too long on pitches low and away, for example, the motusBATTING app will identify that and suggest drills the hitter can use to improve. The app actually estimates pitch location automatically, based on where the hitter is standing in the box, bat length, and batter height.
Both the motusPRO and motusBASEBALL systems rely on improvements to the IMU sensor found in the mThrow. The new IMUs feature an expanded accelerometer range (+/-24 g, up from +/-16 g) and a souped-up onboard processor. The gyroscope range (+/-4000 degrees per second) and sampling frequency (1000 Hz) are unchanged from the previous version.
The sensor design has changed, too, slimming down from 16 mm thick to 9 mm and charging by micro USB instead of induction (for speed and ease of use). When used in the motusPRO application, the sensors synchronize once every minute, enabling the system to capture time-sensitive biomechanics information.
"For instance, peak trunk speed can occur within 20 milliseconds of ball release," Hansen said. "If we were out of sync by even the slightest, we wouldn’t be able to tell you any meaningful information about the kinetic chain."
Although the motusPRO system is available only to professional organizations, the motusBASEBALL system will go on sale in the coming weeks, with the first sensors tentatively scheduled for shipping by the end of the month. Hansen said the company has grown in the year since the mThrow launch and is excited about the promise of their new offerings.
"We’ve now got a year’s worth of data that shows us what a Major League pitcher’s daily throwing regimen and workload profile look like," Hansen said. "We’re a bit older, a bit wiser, and have put a toolset in place to give teams a competitive edge."
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Bryan Cole is a featured writer at Beyond the Box Score. He was not compensated by, nor does he endorse, any of the companies or products mentioned here You can follow him on Twitter at @Doctor_Bryan.