What Mustard Actually Does
Youth sports training tech is full of gadgets that promise elite metrics, but Mustard keeps things surprisingly grounded. You record a pitcher from two specific angles—open side and front view—and the app's computer vision algorithm processes the video into a 3D skeletal overlay. It automatically clips the footage to key biomechanical checkpoints: initial movement, peak leg lift, footstrike, and ball release.
From there, it scores movement patterns against Tom House's database of biomechanical markers. If your pitcher is opening their front hip too early or dragging their arm behind their torso, Mustard highlights the flaw and suggests specific drills to correct it.
Arm Care First
Pitching injuries in youth baseball have surged over the last decade, largely due to year-round play and poor mechanics under fatigue. What sets Mustard apart from raw radar gun apps is its emphasis on arm safety. The app builds custom warm-up and arm care routines tailored to the player's mechanics and workload. It treats biomechanical efficiency as a health requirement, not just a way to add two miles per hour to a fastball.
The Real-World Workflow
To get good data, someone has to stand behind or beside the mound with a steady phone camera. If the camera shakes or the lighting is poor, the skeletal tracking struggles. For kids under 12, this is strictly a joint project—parents manage the device and the recording while the kid throws. High school pitchers can easily use it during bullpen sessions with a cheap tripod.
While basic motion capture tools are available on the free tier, long-term stat tracking and the parent/coach portal sit behind a subscription paywall. If your kid is pitching multiple innings a week, testing the free version during a bullpen session is an easy call before deciding on the paid upgrade.
