what is the lump in the back of rugby shirts

The “lump” you see in the back of professional rugby shirts is the casing for a wearable GPS and biometric tracking device that sits between the player’s shoulder blades, just under the jersey.

What the lump actually is

• It’s a padded, rectangular pouch sewn into the jersey that holds a small tracking unit , often called a GPS pod or “GPS tracker.”

• The unit is usually about the size of a large smartphone or smaller, so it bulges slightly under the thin fabric of the match jersey.

What the device tracks

Modern rugby trackers do a lot more than just positioning:

• Location and movement : speed, distance covered, sprints, accelerations, and decelerations.

• Biomechanics and load : impacts, collisions, heart‑rate–linked effort, and “player load” metrics coaches use to manage fatigue and injury risk.

Why it’s placed on the back

• The small of the back between the shoulder blades is relatively stable and central, so it gives clean, consistent data without being in the way of the ball‑carrier or tackler.

• It’s also a compromise between visibility for TV cameras (it’s clearly visible) and safety (it’s not in the neck or collarbone area).

Is it used in every game?

• In professional and elite rugby (Premiership, Top 14, Super Rugby, World Cup, internationals), players almost always wear these units during training and matches.

• In recreational or club rugby , many teams still don’t use them, so you won’t see the lump on lower‑level squad shirts.

So the next time you’re watching a high‑level game and notice that strange “handle‑like” box on the back of a jersey, it’s essentially a sports‑science data pack that’s quietly logging every sprint, tackle, and metre covered.

Information gathered from public forums or data available on the internet and portrayed here.